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Transcriptional changes of the aging lung. Aging cell Aging is a natural process associated with declined organ function and higher susceptibility to developing chronic diseases. A systemic single-cell type-based study provides a unique opportunity to understand the mechanisms behind age-related pathologies. Here, we use single-cell gene expression analysis comparing healthy young and aged human lungs from nonsmoker donors to investigate age-related transcriptional changes. Our data suggest that aging has a heterogenous effect on lung cells, as some populations are more transcriptionally dynamic while others remain stable in aged individuals. We found that monocytes and alveolar macrophages were the most transcriptionally affected populations. These changes were related to inflammation and regulation of the immune response. Additionally, we calculated the LungAge score, which reveals the diversity of lung cell types during aging. Changes in DNA damage repair, fatty acid metabolism, and inflammation are essential for age prediction. Finally, we quantified the senescence score in aged lungs and found that the more biased cells toward senescence are immune and progenitor cells. Our study provides a comprehensive and systemic analysis of the molecular signatures of lung aging. Our LungAge signature can be used to predict molecular signatures of physiological aging and to detect common signatures of age-related lung diseases. 10.1111/acel.13969
The lung microenvironment shapes a dysfunctional response of alveolar macrophages in aging. The Journal of clinical investigation Alveolar macrophages orchestrate the response to viral infections. Age-related changes in these cells may underlie the differential severity of pneumonia in older patients. We performed an integrated analysis of single-cell RNA-Seq data that revealed homogenous age-related changes in the alveolar macrophage transcriptome in humans and mice. Using genetic lineage tracing with sequential injury, heterochronic adoptive transfer, and parabiosis, we found that the lung microenvironment drove an age-related resistance of alveolar macrophages to proliferation that persisted during influenza A viral infection. Ligand-receptor pair analysis localized these changes to the extracellular matrix, where hyaluronan was increased in aged animals and altered the proliferative response of bone marrow-derived macrophages to granulocyte macrophage colony-stimulating factor (GM-CSF). Our findings suggest that strategies targeting the aging lung microenvironment will be necessary to restore alveolar macrophage function in aging. 10.1172/JCI140299
CD38 Mediates Lung Fibrosis by Promoting Alveolar Epithelial Cell Aging. American journal of respiratory and critical care medicine A prevailing paradigm recognizes idiopathic pulmonary fibrosis (IPF) originating from various alveolar epithelial cell (AEC) injuries, and there is a growing appreciation of AEC aging as a key driver of the pathogenesis. Despite this progress, it is incompletely understood what main factor(s) contribute to the worsened alveolar epithelial aging in lung fibrosis. It remains a challenge how to dampen AEC aging and thereby mitigate the disease progression. To determine the role of AEC CD38 (cluster of differentiation 38) in promoting cellular aging and lung fibrosis. We used single-cell RNA sequencing, real-time PCR, flow cytometry, and Western blotting. We discovered a pivotal role of CD38, a cardinal nicotinamide adenine dinucleotide (NAD) hydrolase, in AEC aging and its promotion of lung fibrosis. We found increased CD38 expression in IPF lungs that inversely correlated with the lung functions of patients. CD38 was primarily located in the AECs of human lung parenchyma and was markedly induced in IPF AECs. Similarly, CD38 expression was elevated in the AECs of fibrotic lungs of young mice and further augmented in those of old mice, which was in accordance with a worsened AEC aging phenotype and an aggravated lung fibrosis in the old animals. Mechanistically, we found that CD38 elevation downregulated intracellular NAD, which likely led to the aging promoting impairment of the NAD-dependent cellular and molecular activities. Furthermore, we demonstrated that genetic and pharmacological inactivation of CD38 improved these NAD dependent events and ameliorated bleomycin-induced lung fibrosis. Our study suggests targeting alveolar CD38 as a novel and effective therapeutic strategy to treat this pathology. 10.1164/rccm.202109-2151OC
Senescence of Alveolar Type 2 Cells Drives Progressive Pulmonary Fibrosis. Yao Changfu,Guan Xiangrong,Carraro Gianni,Parimon Tanyalak,Liu Xue,Huang Guanling,Mulay Apoorva,Soukiasian Harmik J,David Gregory,Weigt Stephen S,Belperio John A,Chen Peter,Jiang Dianhua,Noble Paul W,Stripp Barry R American journal of respiratory and critical care medicine Idiopathic pulmonary fibrosis (IPF) is an insidious and fatal interstitial lung disease associated with declining pulmonary function. Accelerated aging, loss of epithelial progenitor cell function and/or numbers, and cellular senescence are implicated in the pathogenies of IPF. We sought to investigate the role of alveolar type 2 (AT2) cellular senescence in initiation and/or progression of pulmonary fibrosis and therapeutic potential of targeting senescence-related pathways and senescent cells. Epithelial cells of 9 control donor proximal and distal lung tissues and 11 IPF fibrotic lung tissues were profiled by single-cell RNA sequencing to assesses the contribution of epithelial cells to the senescent cell fraction for IPF. A novel mouse model of conditional AT2 cell senescence was generated to study the role of cellular senescence in pulmonary fibrosis. We show that AT2 cells isolated from IPF lung tissue exhibit characteristic transcriptomic features of cellular senescence. We used conditional loss of in adult mouse AT2 cells to initiate a program of p53-dependent cellular senescence, AT2 cell depletion, and spontaneous, progressive pulmonary fibrosis. We establish that senescence rather than loss of AT2 cells promotes progressive fibrosis and show that either genetic or pharmacologic interventions targeting p53 activation or senescence block fibrogenesis. Senescence of AT2 cells is sufficient to drive progressive pulmonary fibrosis. Early attenuation of senescence-related pathways and elimination of senescent cells are promising therapeutic approaches to prevent pulmonary fibrosis. 10.1164/rccm.202004-1274OC
Loss of IGFBP2 mediates alveolar type 2 cell senescence and promotes lung fibrosis. Cell reports. Medicine Accumulation of senescent cells contributes to age-related diseases including idiopathic pulmonary fibrosis (IPF). Insulin-like growth factor binding proteins (IGFBPs) regulate many biological processes; however, the functional contributions of IGFBP2 in lung fibrosis remain largely unclear. Here, we report that intranasal delivery of recombinant IGFBP2 protects aged mice from weight loss and demonstrated antifibrotic effects after bleomycin lung injury. Notably, aged human-Igfbp2 transgenic mice reveal reduced senescence and senescent-associated secretory phenotype factors in alveolar epithelial type 2 (AEC2) cells and they ameliorated bleomycin-induced lung fibrosis. Finally, we demonstrate that IGFBP2 expression is significantly suppressed in AEC2 cells isolated from fibrotic lung regions of patients with IPF and/or pulmonary hypertension compared with patients with hypersensitivity pneumonitis and/or chronic obstructive pulmonary disease. Altogether, our study provides insights into how IGFBP2 regulates AEC2-cell-specific senescence and that restoring IGFBP2 levels in fibrotic lungs can prove effective for patients with IPF. 10.1016/j.xcrm.2023.100945
Targeting Aging Pathways in Chronic Obstructive Pulmonary Disease. International journal of molecular sciences Chronic obstructive pulmonary disease (COPD) has become a global epidemic and is the third leading cause of death worldwide. COPD is characterized by chronic airway inflammation, loss of alveolar-capillary units, and progressive decline in lung function. Major risk factors for COPD are cigarette smoking and aging. COPD-associated pathomechanisms include multiple aging pathways such as telomere attrition, epigenetic alterations, altered nutrient sensing, mitochondrial dysfunction, cell senescence, stem cell exhaustion and chronic inflammation. In this review, we will highlight the current literature that focuses on the role of age and aging-associated signaling pathways as well as their impact on current treatment strategies in the pathogenesis of COPD. Furthermore, we will discuss established and experimental COPD treatments including senolytic and anti-aging therapies and their potential use as novel treatment strategies in COPD. 10.3390/ijms21186924
An atlas of the aging lung mapped by single cell transcriptomics and deep tissue proteomics. Angelidis Ilias,Simon Lukas M,Fernandez Isis E,Strunz Maximilian,Mayr Christoph H,Greiffo Flavia R,Tsitsiridis George,Ansari Meshal,Graf Elisabeth,Strom Tim-Matthias,Nagendran Monica,Desai Tushar,Eickelberg Oliver,Mann Matthias,Theis Fabian J,Schiller Herbert B Nature communications Aging promotes lung function decline and susceptibility to chronic lung diseases, which are the third leading cause of death worldwide. Here, we use single cell transcriptomics and mass spectrometry-based proteomics to quantify changes in cellular activity states across 30 cell types and chart the lung proteome of young and old mice. We show that aging leads to increased transcriptional noise, indicating deregulated epigenetic control. We observe cell type-specific effects of aging, uncovering increased cholesterol biosynthesis in type-2 pneumocytes and lipofibroblasts and altered relative frequency of airway epithelial cells as hallmarks of lung aging. Proteomic profiling reveals extracellular matrix remodeling in old mice, including increased collagen IV and XVI and decreased Fraser syndrome complex proteins and collagen XIV. Computational integration of the aging proteome with the single cell transcriptomes predicts the cellular source of regulated proteins and creates an unbiased reference map of the aging lung. 10.1038/s41467-019-08831-9
YAP1 inhibits the senescence of alveolar epithelial cells by targeting Prdx3 to alleviate pulmonary fibrosis. Experimental & molecular medicine The senescence of alveolar type II (AT2) cells impedes self-repair of the lung epithelium and contributes to lung injury in the setting of idiopathic pulmonary fibrosis (IPF). Yes-associated protein 1 (YAP1) is essential for cell growth and organ development; however, the role of YAP1 in AT2 cells during pulmonary fibrosis is still unclear. YAP1 expression was found to be downregulated in the AT2 cells of PF patients. Deletion of YAP1 in AT2 cells resulted in lung injury, exacerbated extracellular matrix (ECM) deposition, and worsened lung function. In contrast, overexpression of YAP1 in AT2 cells promoted alveolar regeneration, mitigated pulmonary fibrosis, and improved lung function. In addition, overexpression of YAP1 alleviated bleomycin (BLM) -induced senescence of alveolar epithelial cells both in vivo and in vitro. Moreover, YAP1 promoted the expression of peroxiredoxin 3 (Prdx3) by directly interacting with TEAD1. Forced expression of Prdx3 inhibited senescence and improved mitochondrial dysfunction in BLM-treated MLE-12 cells, whereas depletion of Prdx3 partially abrogated the protective effect of YAP1. Furthermore, overexpression of Prdx3 facilitated self-repair of the injured lung and reduced ECM deposition, while silencing Prdx3 attenuated the antifibrotic effect of YAP1. In conclusion, this study demonstrated that YAP1 alleviates lung injury and pulmonary fibrosis by regulating Prdx3 expression to improve mitochondrial dysfunction and block senescence in AT2 cells, revealing a potential novel therapeutic strategy for pulmonary fibrosis. 10.1038/s12276-024-01277-0
Why Does an Aging Smoker's Lung Develop Idiopathic Pulmonary Fibrosis and Not Chronic Obstructive Pulmonary Disease? Selman Moisés,Martinez Fernando J,Pardo Annie American journal of respiratory and critical care medicine 10.1164/rccm.201806-1166PP
The long-term sequelae of COVID-19: an international consensus on research priorities for patients with pre-existing and new-onset airways disease. The Lancet. Respiratory medicine Persistent ill health after acute COVID-19-referred to as long COVID, the post-acute COVID-19 syndrome, or the post-COVID-19 condition-has emerged as a major concern. We undertook an international consensus exercise to identify research priorities with the aim of understanding the long-term effects of acute COVID-19, with a focus on people with pre-existing airways disease and the occurrence of new-onset airways disease and associated symptoms. 202 international experts were invited to submit a minimum of three research ideas. After a two-phase internal review process, a final list of 98 research topics was scored by 48 experts. Patients with pre-existing or post-COVID-19 airways disease contributed to the exercise by weighting selected criteria. The highest-ranked research idea focused on investigation of the relationship between prognostic scores at hospital admission and morbidity at 3 months and 12 months after hospital discharge in patients with and without pre-existing airways disease. High priority was also assigned to comparisons of the prevalence and severity of post-COVID-19 fatigue, sarcopenia, anxiety, depression, and risk of future cardiovascular complications in patients with and without pre-existing airways disease. Our approach has enabled development of a set of priorities that could inform future research studies and funding decisions. This prioritisation process could also be adapted to other, non-respiratory aspects of long COVID. 10.1016/S2213-2600(21)00286-1
Current Status and Future Opportunities in Lung Precision Medicine Research with a Focus on Biomarkers. An American Thoracic Society/National Heart, Lung, and Blood Institute Research Statement. Wu Ann Chen,Kiley James P,Noel Patricia J,Amur Shashi,Burchard Esteban G,Clancy John P,Galanter Joshua,Inada Maki,Jones Tiffanie K,Kropski Jonathan A,Loyd James E,Nogee Lawrence M,Raby Benjamin A,Rogers Angela J,Schwartz David A,Sin Don D,Spira Avrum,Weiss Scott T,Young Lisa R,Himes Blanca E American journal of respiratory and critical care medicine BACKGROUND:Thousands of biomarker tests are either available or under development for lung diseases. In many cases, adoption of these tests into clinical practice is outpacing the generation and evaluation of sufficient data to determine clinical utility and ability to improve health outcomes. There is a need for a systematically organized report that provides guidance on how to understand and evaluate use of biomarker tests for lung diseases. METHODS:We assembled a diverse group of clinicians and researchers from the American Thoracic Society and leaders from the National Heart, Lung, and Blood Institute with expertise in various aspects of precision medicine to review the current status of biomarker tests in lung diseases. Experts summarized existing biomarker tests that are available for lung cancer, pulmonary arterial hypertension, idiopathic pulmonary fibrosis, asthma, chronic obstructive pulmonary disease, sepsis, acute respiratory distress syndrome, cystic fibrosis, and other rare lung diseases. The group identified knowledge gaps that future research studies can address to efficiently translate biomarker tests into clinical practice, assess their cost-effectiveness, and ensure they apply to diverse, real-life populations. RESULTS:We found that the status of biomarker tests in lung diseases is highly variable depending on the disease. Nevertheless, biomarker tests in lung diseases show great promise in improving clinical care. To efficiently translate biomarkers into tests used widely in clinical practice, researchers need to address specific clinical unmet needs, secure support for biomarker discovery efforts, conduct analytical and clinical validation studies, ensure tests have clinical utility, and facilitate appropriate adoption into routine clinical practice. CONCLUSIONS:Although progress has been made toward implementation of precision medicine for lung diseases in clinical practice in certain settings, additional studies focused on addressing specific unmet clinical needs are required to evaluate the clinical utility of biomarkers; ensure their generalizability to diverse, real-life populations; and determine their cost-effectiveness. 10.1164/rccm.201810-1895ST
Proactive Integration of Geriatrics and Palliative Care Principles Into Practice for Chronic Obstructive Pulmonary Disease. Iyer Anand S,Curtis J Randall,Meier Diane E JAMA internal medicine 10.1001/jamainternmed.2020.1088
Research Priorities in Pathophysiology for Sleep-disordered Breathing in Patients with Chronic Obstructive Pulmonary Disease. An Official American Thoracic Society Research Statement. Malhotra Atul,Schwartz Alan R,Schneider Hartmut,Owens Robert L,DeYoung Pamela,Han MeiLan K,Wedzicha Jadwiga A,Hansel Nadia N,Zeidler Michelle R,Wilson Kevin C,Badr M Safwan, American journal of respiratory and critical care medicine BACKGROUND:Obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD) are common conditions; the co-occurrence of these diseases, called the overlap syndrome (OVS), has been associated with poor health outcomes. PURPOSE:The purpose of this Official American Thoracic Society Research Statement is to describe pathophysiology, epidemiology, outcomes, diagnostic metrics, and treatment of OVS, as well as to identify important gaps in knowledge and make recommendations for future research. METHODS:Clinicians and researchers with expertise in sleep medicine, pulmonary medicine, or both were invited to participate. Topics were divided among the participants according to their interest and expertise. A literature search was conducted; the search was not a formal systematic review. Evidence was considered and supplemented with the panelists' nonsystematic clinical observations. Important knowledge gaps were identified. RESULTS:Recommendations for research to fill existing knowledge gaps were made. The recommendations were formulated by discussion and consensus. CONCLUSIONS:Many important questions about OVS exist. This American Thoracic Society Research Statement highlights the types of research that leading clinicians and researchers believe will have the greatest impact on better understanding the spectrum of disease, improving diagnosis, and optimizing therapy. 10.1164/rccm.201712-2510ST
Prevalence of chronic obstructive pulmonary disease in the global population with HIV: a systematic review and meta-analysis. Bigna Jean Joel,Kenne Angeladine Malaha,Asangbeh Serra Lem,Sibetcheu Aurelie T The Lancet. Global health BACKGROUND:In recent years, the concept has been raised that people with HIV are at risk of developing chronic obstructive pulmonary disease (COPD) because of HIV infection. However, much remains to be understood about the relationship between COPD and HIV infection. We aimed to investigate this association by assessing studies that reported the prevalence of COPD in the global population with HIV. METHODS:In this systematic review and meta-analysis, we assessed observational studies of COPD in people with HIV. We searched PubMed, Embase, Web of Science, and Global Index Medicus, with no language restriction, to identify articles published until June 21, 2017, and we searched the reference lists of the retrieved articles. Eligible studies reported the prevalence of COPD or had enough data to compute these estimates. We excluded studies in subgroups of participants selected on the basis of the presence of COPD; studies that were limited to other specific groups or populations, such as people with other chronic respiratory diseases; and case series, letters, reviews, commentaries, editorials, and studies without primary data or an explicit description of methods. The main outcome assessed was prevalence of COPD. Each study was independently reviewed for methodological quality. We used a random-effects model to pool individual studies and assessed heterogeneity (I) using the χ test on Cochrane's Q statistic. This study is registered with PROSPERO, number CRD42016052639. FINDINGS:Of 4036 studies identified, we included 30 studies (151 686 participants) from all WHO regions in the meta-analysis of COPD prevalence. 23 studies (77%) had low risk of bias, six (20%) had moderate risk of bias, and one (3%) had high risk of bias in their methodological quality. The overall prevalence of COPD was 10·5% (95% CI 6·2-15·7; I=97·2%; six studies) according to the lower limit of normal definition of COPD, and 10·6% (6·9-15·0; 94·7%; 16 studies) according to the fixed-ratio definition. COPD prevalence was higher in Europe and among current and ever smokers, and increased with level of income and proportion of participants with detectable HIV viral load. Prevalence of COPD was significantly higher in patients with HIV than in HIV-negative controls (pooled odds ratio 1·14, 95% CI 1·05-1·25, I=63·5%; 11 studies), even after adjustment for tobacco consumption (2·58, 1·05-6·35, 74·9%; four studies). INTERPRETATION:Our findings suggest a high prevalence of COPD in the global population with HIV, and an association with HIV. As such, COPD deserves more attention from HIV health-care providers, researchers, policy makers, and stakeholders for improved detection, overall proper management, and efficient control of COPD in people with HIV. Efforts to address this burden should focus on promoting the decrease of tobacco consumption and adherence to highly active antiretroviral therapy to reduce viral load. FUNDING:None. 10.1016/S2214-109X(17)30451-5
Blood Eosinophil Counts in Clinical Trials for Chronic Obstructive Pulmonary Disease. American journal of respiratory and critical care medicine 10.1164/rccm.201912-2384PP
Key roles for lipid mediators in the adaptive immune response. Duffney Parker F,Falsetta Megan L,Rackow Ashley R,Thatcher Thomas H,Phipps Richard P,Sime Patricia J The Journal of clinical investigation Chronic inflammation is an underlying feature of many diseases, including chronic obstructive pulmonary disease, rheumatoid arthritis, asthma, and multiple sclerosis. There is an increasing appreciation of the dysregulation of adaptive immunity in chronic inflammatory and allergic diseases. The discovery of specialized pro-resolving lipid mediators (SPMs) that actively promote the resolution of inflammation has opened new avenues for the treatment of chronic inflammatory diseases. Much work has been done focusing on the impact of SPMs on innate immune cells. However, much less is known about the influence of SPMs on the development of antigen-specific adaptive immune responses. This Review highlights the important breakthroughs concerning the effects of SPMs on the key cell types involved in the development of adaptive immunity, namely dendritic cells, T cells, and B cells. 10.1172/JCI97951
Elevated Plasmin(ogen) as a Common Risk Factor for COVID-19 Susceptibility. Physiological reviews Patients with hypertension, diabetes, coronary heart disease, cerebrovascular illness, chronic obstructive pulmonary disease, and kidney dysfunction have worse clinical outcomes when infected with SARS-CoV-2, for unknown reasons. The purpose of this review is to summarize the evidence for the existence of elevated plasmin(ogen) in COVID-19 patients with these comorbid conditions. Plasmin, and other proteases, may cleave a newly inserted furin site in the S protein of SARS-CoV-2, extracellularly, which increases its infectivity and virulence. Hyperfibrinolysis associated with plasmin leads to elevated D-dimer in severe patients. The plasmin(ogen) system may prove a promising therapeutic target for combating COVID-19. 10.1152/physrev.00013.2020
Swallow and Aspiration in Chronic Obstructive Pulmonary Disease. Cvejic Lydia,Bardin Philip G American journal of respiratory and critical care medicine 10.1164/rccm.201804-0704PP
Update in Chronic Obstructive Pulmonary Disease 2019. American journal of respiratory and critical care medicine 10.1164/rccm.202002-0370UP
Treating Hypertension in Chronic Obstructive Pulmonary Disease. Finks Shannon W,Rumbak Mark J,Self Timothy H The New England journal of medicine 10.1056/NEJMra1805377
American Thoracic Society/National Heart, Lung, and Blood Institute Asthma-Chronic Obstructive Pulmonary Disease Overlap Workshop Report. Woodruff Prescott G,van den Berge Maarten,Boucher Richard C,Brightling Christopher,Burchard Esteban G,Christenson Stephanie A,Han MeiLan K,Holtzman Michael J,Kraft Monica,Lynch David A,Martinez Fernando D,Reddel Helen K,Sin Don D,Washko George R,Wenzel Sally E,Punturieri Antonello,Freemer Michelle M,Wise Robert A American journal of respiratory and critical care medicine Asthma and chronic obstructive pulmonary disease (COPD) are highly prevalent chronic obstructive lung diseases with an associated high burden of disease. Asthma, which is often allergic in origin, frequently begins in infancy or childhood with variable airflow obstruction and intermittent wheezing, cough, and dyspnea. Patients with COPD, in contrast, are usually current or former smokers who present after the age of 40 years with symptoms (often persistent) including dyspnea and a productive cough. On the basis of age and smoking history, it is often easy to distinguish between asthma and COPD. However, some patients have features compatible with both diseases. Because clinical studies typically exclude these patients, their underlying disease mechanisms and appropriate treatment remain largely uncertain. To explore the status of and opportunities for research in this area, the NHLBI, in partnership with the American Thoracic Society, convened a workshop of investigators in San Francisco, California on May 14, 2016. At the workshop, current understanding of asthma-COPD overlap was discussed among clinicians, pathologists, radiologists, epidemiologists, and investigators with expertise in asthma and COPD. They considered knowledge gaps in our understanding of asthma-COPD overlap and identified strategies and research priorities that will advance its understanding. This report summarizes those discussions. 10.1164/rccm.201705-0973WS
International Differences in the Frequency of Chronic Obstructive Pulmonary Disease Exacerbations Reported in Three Clinical Trials. American journal of respiratory and critical care medicine Exacerbations of chronic obstructive pulmonary disease (COPD) are an important endpoint in multinational clinical treatment trials, but the observed event rate is often lower than anticipated and appears to vary between countries. We investigated whether systematic differences in national exacerbation rates might explain this observed variation. We reviewed data from three large multicenter international randomized trials conducted over an 18-year period with different designs and clinical severities of COPD, comparing bronchodilator and/or inhaled corticosteroids with bronchodilators alone and/or placebo. Exacerbations were defined by antibiotic and/or oral corticosteroid use (moderate) or need for hospitalization (severe). We calculated crude exacerbation rates in the 30 countries contributing 30 or more patients to at least two trials. We grouped data by exacerbation rate based on their first study contribution. For the 29,756 patients in 41 countries analyzed, the mean exacerbation rate was two- to threefold different between the highest and lowest tertiles of the recruiting nations. These differences were not explained by demographic features, study protocol, or reported exacerbation history at enrollment. Of the 18 countries contributing to all trials, half of those in the highest and half in the lowest tertiles of exacerbation history remained in these groups across trials. Severe exacerbations showed a different rank order internationally. Countries contributing to COPD trials differ consistently in their reporting of healthcare-defined exacerbations. These differences help explain why large studies have been needed to show differences between treatments that decrease exacerbation risk. 10.1164/rccm.202111-2630OC
Idiopathic pulmonary fibrosis: effects and optimal management of comorbidities. King Christopher S,Nathan Steven D The Lancet. Respiratory medicine Despite the development of pharmacological therapies that are effective in slowing the progression of idiopathic pulmonary fibrosis (IPF), it remains a debilitating and lethal condition. In addition to the adverse effects caused by pulmonary fibrosis, most patients with IPF have associated comorbid conditions, which might negatively affect functional status, quality of life, and survival. Comorbid conditions can be pulmonary or extrapulmonary. Pulmonary comorbidities include pulmonary hypertension, emphysema, and lung cancer, while non-pulmonary conditions include venous thromboembolism, coronary artery disease, congestive heart failure, sleep-disordered breathing, gastro-oesophageal reflux disease, and anxiety or depression. Although some of these comorbid conditions share risk factors with IPF, the likelihood for their presence or development in patients with IPF is still greater than expected. This might indicate that IPF fosters an environment for the development or perpetuation of comorbid conditions, or alternatively that they share causative factors. Optimal management of IPF therefore requires a comprehensive approach, which includes the identification and treatment of comorbid conditions to optimise patient outcomes. 10.1016/S2213-2600(16)30222-3
How Do Dual Long-Acting Bronchodilators Prevent Exacerbations of Chronic Obstructive Pulmonary Disease? Beeh Kai M,Burgel Pierre-Regis,Franssen Frits M E,Lopez-Campos Jose Luis,Loukides Stelios,Hurst John R,Fležar Matjaž,Ulrik Charlotte Suppli,Di Marco Fabiano,Stolz Daiana,Valipour Arschang,Casserly Brian,Ställberg Björn,Kostikas Konstantinos,Wedzicha Jadwiga A American journal of respiratory and critical care medicine Decreasing the frequency and severity of exacerbations is one of the main goals of treatment for patients with chronic obstructive pulmonary disease. Several studies have documented that long-acting bronchodilators can reduce exacerbation rate and/or severity, and others have shown that combinations of long-acting β-adrenergic agonists (LABAs) and long-acting muscarinic antagonists (LAMAs) provide greater reductions in exacerbation frequency than either their monocomponents or LABA/inhaled corticosteroid combinations in patients at low and high risk for these events. In this review, small groups of experts critically evaluated mechanisms potentially responsible for the increased benefit of LABA/LAMA combinations over single long-acting bronchodilators or LABA/inhaled corticosteroids in decreasing exacerbation. These included effects on lung hyperinflation and mechanical stress, inflammation, excessive mucus production with impaired mucociliary clearance, and symptom severity. The data assembled and analyzed by each group were reviewed by all authors and combined into this manuscript. Available clinical results support the possibility that effects of LABA/LAMA combinations on hyperinflation, mucociliary clearance, and symptom severity may all contribute to decreasing exacerbations. Although preclinical studies suggest LABAs and LAMAs have antiinflammatory effects, such effects have not been demonstrated yet in patients with chronic obstructive pulmonary disease. 10.1164/rccm.201609-1794CI
The Purinergic System as a Pharmacological Target for the Treatment of Immune-Mediated Inflammatory Diseases. Pharmacological reviews Immune-mediated inflammatory diseases (IMIDs) encompass a wide range of seemingly unrelated conditions, such as multiple sclerosis, rheumatoid arthritis, psoriasis, inflammatory bowel diseases, asthma, chronic obstructive pulmonary disease, and systemic lupus erythematosus. Despite differing etiologies, these diseases share common inflammatory pathways, which lead to damage in primary target organs and frequently to a plethora of systemic effects as well. The purinergic signaling complex comprising extracellular nucleotides and nucleosides and their receptors, the P2 and P1 purinergic receptors, respectively, as well as catabolic enzymes and nucleoside transporters is a major regulatory system in the body. The purinergic signaling complex can regulate the development and course of IMIDs. Here we provide a comprehensive review on the role of purinergic signaling in controlling immunity, inflammation, and organ function in IMIDs. In addition, we discuss the possible therapeutic applications of drugs acting on purinergic pathways, which have been entering clinical development, to manage patients suffering from IMIDs. 10.1124/pr.117.014878
Lipid-based biomarkers for CVD, COPD, and aging - A translational perspective. Ekroos Kim,Lavrynenko Oksana,Titz Bjoern,Pater Calin,Hoeng Julia,Ivanov Nikolai V Progress in lipid research For many diseases, there is an unmet need for new or better biomarkers for improved disease risk assessment and monitoring, as available markers lack sufficient specificity. Lipids are drawing major interest as potential candidates for filling these gaps. This has recently been demonstrated by the identification of selective ceramides for prediction of cardiovascular mortality, enabling improved risk assessment of cardiovascular disease compared with conventional clinical markers. In this review, we discuss current lipid biomarker findings and the possible connection between cardiovascular disease, chronic obstructive pulmonary disease, and aging. Moreover, we discuss how to overcome the current roadblocks facing lipid biomarker research. We stress the need for improved quantification, standardization of methodologies, and establishment of initial reference values to allow for an efficient transfer path of research findings into the clinical landscape, and, ultimately, to put newly identified biomarkers into practical use. 10.1016/j.plipres.2020.101030
What does endotyping mean for treatment in chronic obstructive pulmonary disease? Agustí Alvar,Celli Bartolome,Faner Rosa Lancet (London, England) Chronic obstructive pulmonary disease (COPD) is a complex and heterogeneous disease, both at the clinical and biological level. However, COPD is still diagnosed and treated according to simple clinical measures (level of airflow limitation, symptoms, and frequency of previous exacerbations). To address this clinical and biological complexity and to move towards precision medicine in COPD, we need to integrate (bioinformatics) and interpret (clinical science) the vast amount of high-throughput information that existing technology provides (systems biology and network medicine) so diagnosis, stratification, and treatment of patients with COPD can occur on the basis of their pathobiological mechanism (ie, endotypes). Therefore, this Series paper discusses a possible new taxonomy of COPD, the role of endotypes and associated biomarkers and phenotypes, the gaps (and opportunities) in existing knowledge of COPD pathobiology, how systems biology and network medicine can improve understanding of the disease and help to identify relevant endotypes and their specific biomarkers, and how endotypes and their biomarkers can improve the precision, effectiveness, and safety of the treatment of patients with COPD. 10.1016/S0140-6736(17)32136-0
A Pandemic Lesson for Global Lung Diseases: Exacerbations Are Preventable. American journal of respiratory and critical care medicine A dramatic global reduction in the incidence of common seasonal respiratory viral infections has resulted from measures to limit the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the pandemic. This has been accompanied by falls reaching 50% internationally in the incidence of acute exacerbations of preexisting chronic respiratory diseases that include asthma, chronic obstructive pulmonary disease, and cystic fibrosis. At the same time, the incidence of acute bacterial pneumonia and sepsis has fallen steeply worldwide. Such findings demonstrate the profound impact of common respiratory viruses on the course of these global illnesses. Reduced transmission of common respiratory bacterial pathogens and their interactions with viruses appear also as central factors. This review summarizes pandemic changes in exacerbation rates of asthma, chronic obstructive pulmonary disease, cystic fibrosis, and pneumonia. We draw attention to the substantial body of knowledge about respiratory virus infections in these conditions, and that it has not yet translated into clinical practice. Now that the large scale of benefits that could be gained by managing these pathogens is unmistakable, we suggest that the field merits substantial academic and industrial investment. We consider how pandemic-inspired measures for prevention and treatment of common infections should become a cornerstone for managing respiratory diseases. 10.1164/rccm.202110-2389CI
Diagnostic and Therapeutic Gaps in Patients With Heart Failure and Chronic Obstructive Pulmonary Disease. Canepa Marco,Franssen Frits M E,Olschewski Horst,Lainscak Mitja,Böhm Michael,Tavazzi Luigi,Rosenkranz Stephan JACC. Heart failure Heart failure (HF) and chronic obstructive pulmonary disease (COPD) coincide in a significant number of patients. Recent population-based registries suggest that spirometry is largely underused in patients with HF to diagnose comorbid COPD and that patients with COPD frequently do not receive the recommended beta-blocker (BB) treatment. This state-of-the-art review summarizes: 1) current challenges in the implementation of recommended spirometry for COPD diagnosis in patients with HF; and 2) current underuse and underdosing of BBs in patients with HF and COPD despite guideline recommendations. Open issues in the therapeutic management of patients with HF and COPD are discussed in the third section, including the use of the nonselective BB carvedilol, target BB doses in patients with HF and COPD, BB and bronchodilator management during HF hospitalization with and without COPD exacerbation, and the use of BBs in patients with COPD with right HF or free from cardiovascular disease. The whole scenario described herein advocates for a bipartisan initiative to drive immediate attention to the translation of guideline recommendations into clinical practice for patients with HF with co-occurring COPD. 10.1016/j.jchf.2019.05.009
NCD Countdown 2030: pathways to achieving Sustainable Development Goal target 3.4. Lancet (London, England) The Sustainable Development Goal (SDG) target 3.4 is to reduce premature mortality from non-communicable diseases (NCDs) by a third by 2030 relative to 2015 levels, and to promote mental health and wellbeing. We used data on cause-specific mortality to characterise the risk and trends in NCD mortality in each country and evaluate combinations of reductions in NCD causes of death that can achieve SDG target 3.4. Among NCDs, ischaemic heart disease is responsible for the highest risk of premature death in more than half of all countries for women, and more than three-quarters for men. However, stroke, other cardiovascular diseases, and some cancers are associated with a similar risk, and in many countries, a higher risk of premature death than ischaemic heart disease. Although premature mortality from NCDs is declining in most countries, for most the pace of change is too slow to achieve SDG target 3.4. To investigate the options available to each country for achieving SDG target 3.4, we considered different scenarios, each representing a combination of fast (annual rate achieved by the tenth best performing percentile of all countries) and average (median of all countries) declines in risk of premature death from NCDs. Pathways analysis shows that every country has options for achieving SDG target 3.4. No country could achieve the target by addressing a single disease. In at least half the countries, achieving the target requires improvements in the rate of decline in at least five causes for women and in at least seven causes for men to the same rate achieved by the tenth best performing percentile of all countries. Tobacco and alcohol control and effective health-system interventions-including hypertension and diabetes treatment; primary and secondary cardiovascular disease prevention in high-risk individuals; low-dose inhaled corticosteroids and bronchodilators for asthma and chronic obstructive pulmonary disease; treatment of acute cardiovascular diseases, diabetes complications, and exacerbations of asthma and chronic obstructive pulmonary disease; and effective cancer screening and treatment-will reduce NCD causes of death necessary to achieve SDG target 3.4 in most countries. 10.1016/S0140-6736(20)31761-X
Home Oxygen in Chronic Obstructive Pulmonary Disease. Lacasse Yves,Tan Ai-Yui M,Maltais François,Krishnan Jerry A American journal of respiratory and critical care medicine Two landmark trials conducted more than 35 years ago provided scientific evidence that, under very specific circumstances, long-term oxygen therapy (LTOT) may prolong life. These two trials enrolled 290 patients with chronic obstructive pulmonary disease and severe daytime hypoxemia documented by direct arterial blood gas measurement. From that time, LTOT became a standard of care, and the indications for oxygen therapy expanded to include nocturnal oxygen therapy for isolated nocturnal oxygen desaturation, ambulatory oxygen to correct exercise-induced desaturation, and short-burst oxygen to relieve dyspnea. In most cases, the rationale for broadening the indications for oxygen therapy is that, if hypoxemia exists, correcting it by increasing the Fi should help. However, with the exception of LTOT in severely hypoxemic patients with chronic obstructive pulmonary disease, randomized controlled trials of oxygen therapy have failed to demonstrate clinically significant benefits. Also, adherence to LTOT is usually suboptimal. Important areas for future research include improving understanding of the mechanisms of action of supplemental oxygen, the clinical and biochemical predictors of responsiveness to LTOT, the methods for measuring and enhancing adherence to LTOT, and the cost-effectiveness of oxygen therapy. A standardization of terminology to describe the use of supplemental oxygen at home is provided. 10.1164/rccm.201802-0382CI
Chronic Obstructive Pulmonary Disease Biomarkers and Their Interpretation. Stockley Robert A,Halpin David M G,Celli Bartolome R,Singh Dave American journal of respiratory and critical care medicine The pathology and impact of chronic obstructive pulmonary disease (COPD) results from an abnormal inflammatory process resulting in tissue damage with ineffective repair in response to toxic inhalants (especially cigarette smoke). Identification of mechanisms provides the opportunity to develop new therapies and a personalized approach to management. The collection of multiple genetic and detailed biochemical data from small and large patient cohorts has led to an explosion of studies investigating biomarkers to achieve these aims. Despite widespread enthusiasm and many statistically significant associations, the interpretation of COPD biomarker results requires thought and leaves many questions unanswered. The present review assesses the importance of these associations, whether they represent cause or effect, reflect disease severity or activity, the complexity of the pathway to the final pathogenic and hence interventional step, and problems with interpreting cross-sectional studies without knowing individual disease trajectories. The complexity of biomarker specificity without sufficient clinical phenotype and endotype information contributes to problems of interpretation. A strategic change is needed to develop useful COPD biomarkers; this includes focusing on endotype biomarkers within specific clinical phenotypes, biomarkers in early COPD, exacerbation subtype biomarkers, and biomarkers to predict or measure drug effects. 10.1164/rccm.201810-1860SO
β-adrenoreceptors and the risk of Parkinson's disease. Hopfner Franziska,Höglinger Günter U,Kuhlenbäumer Gregor,Pottegård Anton,Wod Mette,Christensen Kaare,Tanner Caroline M,Deuschl Günther The Lancet. Neurology BACKGROUND:β-adrenoceptors are widely expressed in different human organs, mediate important body functions and are targeted by medications for various diseases (such as coronary heart disease and heart attack) and many β-adrenoceptor acting drugs are listed on the WHO Model List of Essential Medicines. β-adrenoceptor antagonists are used by billions of patients with neurological disorders, primarily for the treatment of migraine and action tremor (mainly essential tremor), worldwide. RECENT DEVELOPMENTS:An observational study reported a link between the chronic use of the β-adrenoceptor antagonist propranolol and an increased risk of Parkinson's disease, while the chronic use of the β-adrenoceptor agonists was associated with a decreased risk. Further support of this association was provided by a dose-dependent decrease in the risk of Parkinson's disease with chronic β-adrenoceptor agonist (eg, salbutamol) use, and by functional data indicating a possible underlying molecular mechanism. Five additional epidemiological studies have examined the modulation of the risk of Parkinson's disease as a result of the use of β-adrenoceptor-acting drugs in different populations. Overall, similar estimates but different interpretations of the associations were provided. Several findings suggest that the increase in risk of Parkinson's disease associated with β-adrenoceptor antagonists use can be explained by reverse causation because prodromal Parkinson's disease is often associated with non-specific action tremor, which is usually treated with propranolol. The lower risk of Parkinson's disease seen in patients receiving β-adrenoceptor agonists is likely to be indirectly mediated by smoking because smoking has a strong inverse association with Parkinson's disease (people that smoke have a reduced risk of developing Parkinson's disease). Smoking also causes chronic obstructive pulmonary disease, which is treated with β-adrenoceptor-agonist medications. Even if causal, the effect of β-adrenoceptor antagonists on the risk of Parkinson's disease would be small compared with other Parkinson's disease risk factors and would be similar to the risk evoked by pesticide exposure. The estimated risk of Parkinson's disease because of β-adrenoceptor antagonists use corresponds to one case in 10 000 patients after 5 years of propranolol use, and would be considered a very rare adverse effect. Thus, not using β-adrenoceptor antagonists would severely harm patients with recommended indications, such as heart disease or migraine. Similarly, 50 000 people would have to be treated for 5 years with salbutamol to prevent Parkinson's disease in one patient, suggesting that primary preventive therapy studies on disease modification are not warranted. WHERE NEXT?: Epidemiological evidence for a causal relationship between use of β2-adrenoceptor antagonists and the increased risk of Parkinson's disease is weak, with other explanations for the association being more probable. Future observational studies are warranted to clarify this association. However, given the very low risk associated with propranolol, most clinicians are unlikely to change their treatment approach. 10.1016/S1474-4422(19)30400-4
Inhaled Medicines: Past, Present, and Future. Anderson Sandra,Atkins Paul,Bäckman Per,Cipolla David,Clark Andrew,Daviskas Evangelia,Disse Bernd,Entcheva-Dimitrov Plamena,Fuller Rick,Gonda Igor,Lundbäck Hans,Olsson Bo,Weers Jeffry Pharmacological reviews The purpose of this review is to summarize essential pharmacological, pharmaceutical, and clinical aspects in the field of orally inhaled therapies that may help scientists seeking to develop new products. After general comments on the rationale for inhaled therapies for respiratory disease, the focus is on products approved approximately over the last half a century. The organization of these sections reflects the key pharmacological categories. Products for asthma and chronic obstructive pulmonary disease include -2 receptor agonists, muscarinic acetylcholine receptor antagonists, glucocorticosteroids, and cromones as well as their combinations. The antiviral and antibacterial inhaled products to treat respiratory tract infections are then presented. Two "mucoactive" products-dornase and mannitol, which are both approved for patients with cystic fibrosis-are reviewed. These are followed by sections on inhaled prostacyclins for pulmonary arterial hypertension and the challenging field of aerosol surfactant inhalation delivery, especially for prematurely born infants on ventilation support. The approved products for systemic delivery via the lungs for diseases of the central nervous system and insulin for diabetes are also discussed. New technologies for drug delivery by inhalation are analyzed, with the emphasis on those that would likely yield significant improvements over the technologies in current use or would expand the range of drugs and diseases treatable by this route of administration. SIGNIFICANCE STATEMENT: This review of the key aspects of approved orally inhaled drug products for a variety of respiratory diseases and for systemic administration should be helpful in making judicious decisions about the development of new or improved inhaled drugs. These aspects include the choices of the active ingredients, formulations, delivery systems suitable for the target patient populations, and, to some extent, meaningful safety and efficacy endpoints in clinical trials. 10.1124/pharmrev.120.000108
Genetic Advances in Chronic Obstructive Pulmonary Disease. Insights from COPDGene. Ragland Margaret F,Benway Christopher J,Lutz Sharon M,Bowler Russell P,Hecker Julian,Hokanson John E,Crapo James D,Castaldi Peter J,DeMeo Dawn L,Hersh Craig P,Hobbs Brian D,Lange Christoph,Beaty Terri H,Cho Michael H,Silverman Edwin K American journal of respiratory and critical care medicine Chronic obstructive pulmonary disease (COPD) is a common and progressive disease that is influenced by both genetic and environmental factors. For many years, knowledge of the genetic basis of COPD was limited to Mendelian syndromes, such as alpha-1 antitrypsin deficiency and cutis laxa, caused by rare genetic variants. Over the past decade, the proliferation of genome-wide association studies, the accessibility of whole-genome sequencing, and the development of novel methods for analyzing genetic variation data have led to a substantial increase in the understanding of genetic variants that play a role in COPD susceptibility and COPD-related phenotypes. COPDGene (Genetic Epidemiology of COPD), a multicenter, longitudinal study of over 10,000 current and former cigarette smokers, has been pivotal to these breakthroughs in understanding the genetic basis of COPD. To date, over 20 genetic loci have been convincingly associated with COPD affection status, with additional loci demonstrating association with COPD-related phenotypes such as emphysema, chronic bronchitis, and hypoxemia. In this review, we discuss the contributions of the COPDGene study to the discovery of these genetic associations as well as the ongoing genetic investigations of COPD subtypes, protein biomarkers, and post-genome-wide association study analysis. 10.1164/rccm.201808-1455SO
Cystic Fibrosis Transmembrane Conductance Regulator: Roles in Chronic Obstructive Pulmonary Disease. Dransfield Mark,Rowe Steven,Vogelmeier Claus F,Wedzicha Jadwiga,Criner Gerard J,Han MeiLan K,Martinez Fernando J,Calverley Peter American journal of respiratory and critical care medicine Chronic obstructive pulmonary disease (COPD) manifests with a variety of clinical presentations, reflecting its complex pathology. Currently, care focuses on symptom amelioration and prevention of complications and thus is generally tailored to disease severity rather than targeting specific pathophysiologic mechanisms. Chronic inflammation and mucus hypersecretion are key features of COPD. Epithelial ion channel dysfunction may be important, as it results in airway dehydration and defective host defense, contributing to chronic airway inflammation. Recent evidence suggests considerable similarities between COPD and cystic fibrosis (CF), a disease in which chloride ion channel dysfunction has been extensively studied (in particular CFTR [CF transmembrane conductance regulator]). Understanding commonalities between CF and COPD, and the role of CFTR in CF, may help in designing strategies targeting ion channel dysfunction and lead to new treatments with potential to alter the natural history of disease progression. Here, we review the roles of airway mucus and CFTR in normal lung function, the previously underestimated contribution of mucus stasis to the development of COPD, and the evidence for targeting CFTR to counteract mucus accumulation. 10.1164/rccm.202109-2064TR
Underdiagnosis and Overdiagnosis of Chronic Obstructive Pulmonary Disease. Diab Nermin,Gershon Andrea S,Sin Don D,Tan Wan C,Bourbeau Jean,Boulet Louis-Philippe,Aaron Shawn D American journal of respiratory and critical care medicine Chronic obstructive pulmonary disease (COPD) is regarded as one of the leading causes of morbidity and mortality across the world, yet its proper diagnosis remains a challenge. Community-based population studies conducted in North and South America, Europe, Australia, and Asia have revealed that 10% to 12% of adults aged 40 years or older have evidence of persistent airflow limitation on spirometry, but only 20% to 30% of these subjects have been diagnosed with COPD. These studies collectively suggest that approximately 70% of COPD worldwide may be underdiagnosed. Conversely, other studies have shown that between 30% and 60% of patients with a previous physician diagnosis of COPD do not actually have the disease, and hence they have been overdiagnosed. In this review, we define under- and overdiagnosis and explore the prevalence and the burden of under- and overdiagnosis of COPD on both patients and healthcare systems. We further describe potential solutions to reduce the incidence of under- and overdiagnosis of COPD. 10.1164/rccm.201804-0621CI
Early Life Microbiota and Respiratory Tract Infections. de Steenhuijsen Piters Wouter A A,Binkowska Justyna,Bogaert Debby Cell host & microbe Over the last decade, it has become clear that respiratory and intestinal tract microbiota are related to pathogenesis of respiratory tract infections (RTIs). Host and environmental factors can drive respiratory microbiota maturation in early life, which in turn is related to consecutive susceptibility to RTIs. Moreover, during RTIs, including viral bronchiolitis, the local microbiome appears to play an immunomodulatory role through complex interactions, though causality has not yet been fully demonstrated. The microbiota is subsequently associated with recovery after RTIs and can be related to persistent or long-term sequelae. In this Review, we explore the epidemiological evidence supporting these associations and link to mechanistic insights. The long-term consequences of childhood RTIs and the comprehensive role of the microbiota at various stages in RTI pathogenesis call for early life preventative and therapeutic interventions to promote respiratory health. 10.1016/j.chom.2020.07.004
Neuronal Regulation of Immunity in the Skin and Lungs. Blake Kimbria J,Jiang Xin Ru,Chiu Isaac M Trends in neurosciences The nervous and immune systems are classically studied as two separate entities. However, their interactions are crucial for maintaining barrier functions at tissues constantly exposed to the external environment. We focus here on the role of neuronal signaling in regulating the immune system at two major barriers: the skin and respiratory tract. Barrier tissues are heavily innervated by sensory and autonomic nerves, and are densely populated by resident immune cells, allowing rapid, coordinated responses to noxious stimuli, as well as to bacterial and fungal pathogens. Neural release of neurotransmitters and neuropeptides allows fast communication with immune cells and their recruitment. In addition to maintaining homeostasis and fighting infections, neuroimmune interactions are also implicated in several chronic inflammatory conditions such as atopic dermatitis (AD), chronic obstructive pulmonary disease (COPD), and asthma. 10.1016/j.tins.2019.05.005
Precision Approaches to Chronic Obstructive Pulmonary Disease Management. Annual review of medicine Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. COPD heterogeneity has hampered progress in developing pharmacotherapies that affect disease progression. This issue can be addressed by precision medicine approaches, which focus on understanding an individual's disease risk, and tailoring management based on pathobiology, environmental exposures, and psychosocial issues. There is an urgent need to identify COPD patients at high risk for poor outcomes and to understand at a mechanistic level why certain individuals are at high risk. Genetics, omics, and network analytic techniques have started to dissect COPD heterogeneity and identify patients with specific pathobiology. Drug repurposing approaches based on biomarkers of specific inflammatory processes (i.e., type 2 inflammation) are promising. As larger data sets, additional omics, and new analytical approaches become available, there will be enormous opportunities to identify high-risk individuals and treat COPD patients based on their specific pathophysiological derangements. These approaches show great promise for risk stratification, early intervention, drug repurposing, and developing novel therapeutic approaches for COPD. 10.1146/annurev-med-060622-101239
Blood Eosinophils and Chronic Obstructive Pulmonary Disease: A Global Initiative for Chronic Obstructive Lung Disease Science Committee 2022 Review. American journal of respiratory and critical care medicine 10.1164/rccm.202201-0209PP
The Occupational Burden of Nonmalignant Respiratory Diseases. An Official American Thoracic Society and European Respiratory Society Statement. Blanc Paul D,Annesi-Maesano Isabella,Balmes John R,Cummings Kristin J,Fishwick David,Miedinger David,Murgia Nicola,Naidoo Rajen N,Reynolds Carl J,Sigsgaard Torben,Torén Kjell,Vinnikov Denis,Redlich Carrie A American journal of respiratory and critical care medicine Workplace inhalational hazards remain common worldwide, even though they are ameliorable. Previous American Thoracic Society documents have assessed the contribution of workplace exposures to asthma and chronic obstructive pulmonary disease on a population level, but not to other chronic respiratory diseases. The goal of this document is to report an in-depth literature review and data synthesis of the occupational contribution to the burden of the major nonmalignant respiratory diseases, including airway diseases; interstitial fibrosis; hypersensitivity pneumonitis; other noninfectious granulomatous lung diseases, including sarcoidosis; and selected respiratory infections. Relevant literature was identified for each respiratory condition. The occupational population attributable fraction (PAF) was estimated for those conditions for which there were sufficient population-based studies to allow pooled estimates. For the other conditions, the occupational burden of disease was estimated on the basis of attribution in case series, incidence rate ratios, or attributable fraction within an exposed group. Workplace exposures contribute substantially to the burden of multiple chronic respiratory diseases, including asthma (PAF, 16%); chronic obstructive pulmonary disease (PAF, 14%); chronic bronchitis (PAF, 13%); idiopathic pulmonary fibrosis (PAF, 26%); hypersensitivity pneumonitis (occupational burden, 19%); other granulomatous diseases, including sarcoidosis (occupational burden, 30%); pulmonary alveolar proteinosis (occupational burden, 29%); tuberculosis (occupational burden, 2.3% in silica-exposed workers and 1% in healthcare workers); and community-acquired pneumonia in working-age adults (PAF, 10%). Workplace exposures contribute to the burden of disease across a range of nonmalignant lung conditions in adults (in addition to the 100% burden for the classic occupational pneumoconioses). This burden has important clinical, research, and policy implications. There is a pressing need to improve clinical recognition and public health awareness of the contribution of occupational factors across a range of nonmalignant respiratory diseases. 10.1164/rccm.201904-0717ST
Senescence in COPD and Its Comorbidities. Barnes Peter J Annual review of physiology Chronic obstructive pulmonary disease (COPD) is regarded as a disease of accelerated lung aging. This affliction shows all of the hallmarks of aging, including telomere shortening, cellular senescence, activation of PI3 kinase-mTOR signaling, impaired autophagy, mitochondrial dysfunction, stem cell exhaustion, epigenetic changes, abnormal microRNA profiles, immunosenescence, and a low-grade chronic inflammation (inflammaging). Many of these pathways are driven by chronic exogenous and endogenous oxidative stress. There is also a reduction in antiaging molecules, such as sirtuins and Klotho, which further accelerate the aging process. COPD is associated with several comorbidities (multimorbidity), such as cardiovascular and metabolic diseases, that share the same pathways of accelerated aging. Understanding these mechanisms has helped identify several novel therapeutic targets, and several drugs and dietary interventions are now in development to treat multimorbidity. 10.1146/annurev-physiol-022516-034314
The future of cystic fibrosis treatment: from disease mechanisms to novel therapeutic approaches. Lancet (London, England) With the 2019 breakthrough in the development of highly effective modulator therapy providing unprecedented clinical benefits for over 90% of patients with cystic fibrosis who are genetically eligible for treatment, this rare disease has become a front runner of transformative molecular therapy. This success is based on fundamental research, which led to the identification of the disease-causing CFTR gene and our subsequent understanding of the disease mechanisms underlying the pathogenesis of cystic fibrosis, working together with a continuously evolving clinical research and drug development pipeline. In this Series paper, we focus on advances since 2018, and remaining knowledge gaps in our understanding of the molecular mechanisms of CFTR dysfunction in the airway epithelium and their links to mucus dysfunction, impaired host defences, airway infection, and chronic inflammation of the lungs of people with cystic fibrosis. We review progress in (and the remaining obstacles to) pharmacological approaches to rescue CFTR function, and novel strategies for improved symptomatic therapies for cystic fibrosis, including how these might be applicable to common lung diseases, such as bronchiectasis and chronic obstructive pulmonary disease. Finally, we discuss the promise of genetic therapies and gene editing approaches to restore CFTR function in the lungs of all patients with cystic fibrosis independent of their CFTR genotype, and the unprecedented opportunities to transform cystic fibrosis from a fatal disease to a treatable and potentially curable one. 10.1016/S0140-6736(23)01608-2
Eosinophils in COPD: just another biomarker? Bafadhel Mona,Pavord Ian D,Russell Richard E K The Lancet. Respiratory medicine Eosinophils are innate immune cells that, under certain conditions, can be recruited to the lungs, where they have an incompletely understood role in health and disease. Eosinophils have been found in the airways, tissues, and circulation of patients with COPD, during both stable disease and exacerbations. Epidemiological studies and post-hoc analyses of clinical trials of corticosteroid treatment for COPD have shown that the blood eosinophil count is associated with the risk of COPD exacerbations, mortality, decline in FEV, and response to both inhaled and systemic corticosteroids. Further studies are urgently needed to explore the contribution of eosinophils to the mechanism of disease in COPD and to identify their association with levels of clinical risk. In this review, we explore the role of the eosinophil as a biomarker and mediator of disease in COPD. 10.1016/S2213-2600(17)30217-5
Extracellular Vesicles as Central Mediators of COPD Pathophysiology. Annual review of physiology Chronic obstructive pulmonary disease (COPD) is a complex, heterogeneous, smoking-related disease of significant global impact. The complex biology of COPD is ultimately driven by a few interrelated processes, including proteolytic tissue remodeling, innate immune inflammation, derangements of the host-pathogen response, aberrant cellular phenotype switching, and cellular senescence, among others. Each of these processes are engendered and perpetuated by cells modulating their environment or each other. Extracellular vesicles (EVs) are powerful effectors that allow cells to perform a diverse array of functions on both adjacent and distant tissues, and their pleiotropic nature is only beginning to be appreciated. As such, EVs are candidates to play major roles in these fundamental mechanisms of disease behind COPD. Furthermore, some such roles for EVs are already established, and EVs are implicated in significant aspects of COPD pathogenesis. Here, we discuss known and potential ways that EVs modulate the environment of their originating cells to contribute to the processes that underlie COPD. 10.1146/annurev-physiol-061121-035838
Submassive Pulmonary Embolism. Rali Parth M,Criner Gerard J American journal of respiratory and critical care medicine Pulmonary embolism (PE) presents a spectrum of hemodynamic consequences, ranging from being asymptomatic to a life-threatening medical emergency. Management of submassive and massive PE often involves clinicians from multiple specialties, which can potentially delay the development of a unified treatment plan. In addition, patients with submassive PE can deteriorate after their presentation and require escalation of care. Underlying comorbidities such as chronic obstructive pulmonary disease, cancer, congestive heart failure, and interstitial lung disease can impact the patient's hemodynamic ability to tolerate submassive PE. In this review, we address the definitions, risk stratification (clinical, laboratory, and imaging), management approaches, and long-term outcomes of submassive PE. We also discuss the role of the PE response team in management of patients with PE. 10.1164/rccm.201711-2302CI
Beyond the guidelines for non-invasive ventilation in acute respiratory failure: implications for practice. Bourke Stephen C,Piraino Thomas,Pisani Lara,Brochard Laurent,Elliott Mark W The Lancet. Respiratory medicine Non-invasive ventilation is standard therapy in the management of both hypoxaemic and hypercapnic respiratory failure of various causes. The evidence base for its use and when and how it should be used has been reviewed in two recent guidelines. In this Series paper, we look beyond the guidelines to what is happening in everyday clinical practice in the real world, how patient selection can be refined to maximise the chances of a successful outcome, and emerging alternative therapies. Real-world application of non-invasive ventilation diverges from guideline recommendations, particularly with regard to patient selection and timing of initiation. To improve patient outcomes education programmes need to stress these issues and the effectiveness of non-invasive ventilation that is delivered needs to be monitored by regular audit. 10.1016/S2213-2600(18)30388-6
Pathogenesis of HIV-Related Lung Disease: Immunity, Infection, and Inflammation. Cribbs Sushma K,Crothers Kristina,Morris Alison Physiological reviews Despite anti-retroviral therapy (ART), human immunodeficiency virus-1 (HIV)-related pulmonary disease continues to be a major cause of morbidity and mortality for people living with HIV (PLWH). The spectrum of lung diseases has changed from acute opportunistic infections resulting in death to chronic lung diseases for those with access to ART. Chronic immune activation and suppression can result in impairment of innate immunity and progressive loss of T cell and B cell functionality with aberrant cytokine and chemokine responses systemically as well as in the lung. HIV can be detected in the lungs of PLWH and has profound effects on cellular immune functions. In addition, HIV-related lung injury and disease can occur secondary to a number of mechanisms including altered pulmonary and systemic inflammatory pathways, viral persistence in the lung, oxidative stress with additive effects of smoke exposure, microbial translocation, and alterations in the lung and gut microbiome. Although ART has had profound effects on systemic viral suppression in HIV, the impact of ART on lung immunology still needs to be fully elucidated. Understanding of the mechanisms by which HIV-related lung diseases continue to occur is critical to the development of new preventive and therapeutic strategies to improve lung health in PLWH. 10.1152/physrev.00039.2018
Club Cell Secretory Protein in Lung Disease: Emerging Concepts and Potential Therapeutics. Annual review of medicine Club cell secretory protein (CCSP), also known as secretoglobin 1A1 (gene name ), is one of the most abundant proteins in the lung, primarily produced by club cells of the distal airway epithelium. At baseline, CCSP is found in large concentrations in lung fluid specimens and can also be detected in the blood and urine. Obstructive lung diseases are generally associated with reduced CCSP levels, thought to be due to decreased CCSP production or club cell depletion. Conversely, several restrictive lung diseases have been found to have increased CCSP levels both in the lung and in the circulation, likely related to club cell dysregulation as well as increasedlung permeability. Recent studies demonstrate multiple mechanisms by which CCSP dampens acute and chronic lung inflammation. Given these anti-inflammatory effects, CCSP represents a novel potential therapeutic modality in lung disease. 10.1146/annurev-med-042921-123443
Self-monitoring of blood pressure in hypertension: A systematic review and individual patient data meta-analysis. Tucker Katherine L,Sheppard James P,Stevens Richard,Bosworth Hayden B,Bove Alfred,Bray Emma P,Earle Kenneth,George Johnson,Godwin Marshall,Green Beverly B,Hebert Paul,Hobbs F D Richard,Kantola Ilkka,Kerry Sally M,Leiva Alfonso,Magid David J,Mant Jonathan,Margolis Karen L,McKinstry Brian,McLaughlin Mary Ann,Omboni Stefano,Ogedegbe Olugbenga,Parati Gianfranco,Qamar Nashat,Tabaei Bahman P,Varis Juha,Verberk Willem J,Wakefield Bonnie J,McManus Richard J PLoS medicine BACKGROUND:Self-monitoring of blood pressure (BP) appears to reduce BP in hypertension but important questions remain regarding effective implementation and which groups may benefit most. This individual patient data (IPD) meta-analysis was performed to better understand the effectiveness of BP self-monitoring to lower BP and control hypertension. METHODS AND FINDINGS:Medline, Embase, and the Cochrane Library were searched for randomised trials comparing self-monitoring to no self-monitoring in hypertensive patients (June 2016). Two reviewers independently assessed articles for eligibility and the authors of eligible trials were approached requesting IPD. Of 2,846 articles in the initial search, 36 were eligible. IPD were provided from 25 trials, including 1 unpublished study. Data for the primary outcomes-change in mean clinic or ambulatory BP and proportion controlled below target at 12 months-were available from 15/19 possible studies (7,138/8,292 [86%] of randomised participants). Overall, self-monitoring was associated with reduced clinic systolic blood pressure (sBP) compared to usual care at 12 months (-3.2 mmHg, [95% CI -4.9, -1.6 mmHg]). However, this effect was strongly influenced by the intensity of co-intervention ranging from no effect with self-monitoring alone (-1.0 mmHg [-3.3, 1.2]), to a 6.1 mmHg (-9.0, -3.2) reduction when monitoring was combined with intensive support. Self-monitoring was most effective in those with fewer antihypertensive medications and higher baseline sBP up to 170 mmHg. No differences in efficacy were seen by sex or by most comorbidities. Ambulatory BP data at 12 months were available from 4 trials (1,478 patients), which assessed self-monitoring with little or no co-intervention. There was no association between self-monitoring and either lower clinic or ambulatory sBP in this group (clinic -0.2 mmHg [-2.2, 1.8]; ambulatory 1.1 mmHg [-0.3, 2.5]). Results for diastolic blood pressure (dBP) were similar. The main limitation of this work was that significant heterogeneity remained. This was at least in part due to different inclusion criteria, self-monitoring regimes, and target BPs in included studies. CONCLUSIONS:Self-monitoring alone is not associated with lower BP or better control, but in conjunction with co-interventions (including systematic medication titration by doctors, pharmacists, or patients; education; or lifestyle counselling) leads to clinically significant BP reduction which persists for at least 12 months. The implementation of self-monitoring in hypertension should be accompanied by such co-interventions. 10.1371/journal.pmed.1002389
The vascular perspective on acute and chronic lung disease. The Journal of clinical investigation The pulmonary vasculature has been frequently overlooked in acute and chronic lung diseases, such as acute respiratory distress syndrome (ARDS), pulmonary fibrosis (PF), and chronic obstructive pulmonary disease (COPD). The primary emphasis in the management of these parenchymal disorders has largely revolved around the injury and aberrant repair of epithelial cells. However, there is increasing evidence that the vascular endothelium plays an active role in the development of acute and chronic lung diseases. The endothelial cell network in the capillary bed and the arterial and venous vessels provides a metabolically highly active barrier that controls the migration of immune cells, regulates vascular tone and permeability, and participates in the remodeling processes. Phenotypically and functionally altered endothelial cells, and remodeled vessels, can be found in acute and chronic lung diseases, although to different degrees, likely because of disease-specific mechanisms. Since vascular remodeling is associated with pulmonary hypertension, which worsens patient outcomes and survival, it is crucial to understand the underlying vascular alterations. In this Review, we describe the current knowledge regarding the role of the pulmonary vasculature in the development and progression of ARDS, PF, and COPD; we also outline future research directions with the hope of facilitating the development of mechanism-based therapies. 10.1172/JCI170502
Cell Death in the Lung: The Apoptosis-Necroptosis Axis. Annual review of physiology Regulated cell death is a major mechanism to eliminate damaged, infected, or superfluous cells. Previously, apoptosis was thought to be the only regulated cell death mechanism; however, new modalities of caspase-independent regulated cell death have been identified, including necroptosis, pyroptosis, and autophagic cell death. As an understanding of the cellular mechanisms that mediate regulated cell death continues to grow, there is increasing evidence that these pathways are implicated in the pathogenesis of many pulmonary disorders. This review summarizes our understanding of regulated cell death as it pertains to the pathogenesis of chronic obstructive pulmonary disease, asthma, idiopathic pulmonary fibrosis, acute respiratory distress syndrome, and pulmonary arterial hypertension. 10.1146/annurev-physiol-020518-114320
Pulmonary inflammation and fibroblast immunoregulation: from bench to bedside. The Journal of clinical investigation In recent years, there has been an explosion of interest in how fibroblasts initiate, sustain, and resolve inflammation across disease states. Fibroblasts contain heterogeneous subsets with diverse functionality. The phenotypes of these populations vary depending on their spatial distribution within the tissue and the immunopathologic cues contributing to disease progression. In addition to their roles in structurally supporting organs and remodeling tissue, fibroblasts mediate critical interactions with diverse immune cells. These interactions have important implications for defining mechanisms of disease and identifying potential therapeutic targets. Fibroblasts in the respiratory tract, in particular, determine the severity and outcome of numerous acute and chronic lung diseases, including asthma, chronic obstructive pulmonary disease, acute respiratory distress syndrome, and idiopathic pulmonary fibrosis. Here, we review recent studies defining the spatiotemporal identity of the lung-derived fibroblasts and the mechanisms by which these subsets regulate immune responses to insult exposures and highlight past, current, and future therapeutic targets with relevance to fibroblast biology in the context of acute and chronic human respiratory diseases. This perspective highlights the importance of tissue context in defining fibroblast-immune crosstalk and paves the way for identifying therapeutic approaches to benefit patients with acute and chronic pulmonary disorders. 10.1172/JCI170499
Criteria and definitions for the radiological and clinical diagnosis of bronchiectasis in adults for use in clinical trials: international consensus recommendations. The Lancet. Respiratory medicine Bronchiectasis refers to both a clinical disease and a radiological appearance that has multiple causes and can be associated with a range of conditions. Disease heterogeneity and the absence of standardised definitions have hampered clinical trials of treatments for bronchiectasis and are important challenges in clinical practice. In view of the need for new therapies for non-cystic fibrosis bronchiectasis to reduce the disease burden, we established an international taskforce of experts to develop recommendations and definitions for clinically significant bronchiectasis in adults to facilitate the standardisation of terminology for clinical trials. Systematic reviews were used to inform discussions, and Delphi processes were used to achieve expert consensus. We prioritised criteria for the radiological diagnosis of bronchiectasis and suggest recommendations on the use and central reading of chest CT scans to confirm the presence of bronchiectasis for clinical trials. Furthermore, we developed a set of consensus statements concerning the definitions of clinical bronchiectasis and its specific signs and symptoms, as well as definitions for chronic bacterial infection and sustained culture conversion. The diagnosis of clinically significant bronchiectasis requires both clinical and radiological criteria, and these expert recommendations and proposals should help to optimise patient recruitment into clinical trials and allow reliable comparisons of treatment effects among different interventions for bronchiectasis. Our consensus proposals should also provide a framework for future research to further refine definitions and establish definitive guidance on the diagnosis of bronchiectasis. 10.1016/S2213-2600(21)00277-0
Update on the Pathogenesis of Chronic Obstructive Pulmonary Disease. Agustí Alvar,Hogg James C The New England journal of medicine 10.1056/NEJMra1900475
Genetics of chronic obstructive pulmonary disease: understanding the pathobiology and heterogeneity of a complex disorder. The Lancet. Respiratory medicine Chronic obstructive pulmonary disease (COPD) is a deadly and highly morbid disease. Susceptibility to and heterogeneity of COPD are incompletely explained by environmental factors such as cigarette smoking. Family-based and population-based studies have shown that a substantial proportion of COPD risk is related to genetic variation. Genetic association studies have identified hundreds of genetic variants that affect risk for COPD, decreased lung function, and other COPD-related traits. These genetic variants are associated with other pulmonary and non-pulmonary traits, demonstrate a genetic basis for at least part of COPD heterogeneity, have a substantial effect on COPD risk in aggregate, implicate early-life events in COPD pathogenesis, and often involve genes not previously suspected to have a role in COPD. Additional progress will require larger genetic studies with more ancestral diversity, improved profiling of rare variants, and better statistical methods. Through integration of genetic data with other omics data and comprehensive COPD phenotypes, as well as functional description of causal mechanisms for genetic risk variants, COPD genetics will continue to inform novel approaches to understanding the pathobiology of COPD and developing new strategies for management and treatment. 10.1016/S2213-2600(21)00510-5
Targeting cytokines to treat asthma and chronic obstructive pulmonary disease. Barnes Peter J Nature reviews. Immunology Cytokines play a key role in orchestrating and perpetuating the chronic airway inflammation in asthma and chronic obstructive pulmonary disease (COPD), making them attractive targets for treating these disorders. Asthma and some cases of COPD are mainly driven by type 2 immune responses, which comprise increased airway eosinophils, T helper 2 (T2) cells and group 2 innate lymphoid cells (ILC2s) and the secretion of IL-4, IL-5 and IL-13. Clinical trials of antibodies that block these interleukins have shown reduced acute exacerbations and oral corticosteroid use and improvements in lung function and symptoms in selected patients. More recent approaches that block upstream cytokines, such as thymic stromal lymphopoietin (TSLP), show promise in improving patient outcome. Importantly, the clinical trials in cytokine blockade have highlighted the crucial importance of patient selection for the successful use of these expensive therapies and the need for biomarkers to better predict drug responses. 10.1038/s41577-018-0006-6
Contribution of adaptive immunity to human COPD and experimental models of emphysema. Physiological reviews The pathophysiology of chronic obstructive pulmonary disease (COPD) and the undisputed role of innate immune cells in this condition have dominated the field in the basic research arena for many years. Recently, however, compelling data suggesting that adaptive immune cells may also contribute to the progressive nature of lung destruction associated with COPD in smokers have gained considerable attention. The histopathological changes in the lungs of smokers can be limited to the large or small airways, but alveolar loss leading to emphysema, which occurs in some individuals, remains its most significant and irreversible outcome. Critically, however, the question of why emphysema progresses in a subset of former smokers remained a mystery for many years. The recognition of activated and organized tertiary T- and B-lymphoid aggregates in emphysematous lungs provided the first clue that adaptive immune cells may play a crucial role in COPD pathophysiology. Based on these findings from human translational studies, experimental animal models of emphysema were used to determine the mechanisms through which smoke exposure initiates and orchestrates adaptive autoreactive inflammation in the lungs. These models have revealed that T helper (Th)1 and Th17 subsets promote a positive feedback loop that activates innate immune cells, confirming their role in emphysema pathogenesis. Results from genetic studies and immune-based discoveries have further provided strong evidence for autoimmunity induction in smokers with emphysema. These new findings offer a novel opportunity to explore the mechanisms underlying the inflammatory landscape in the COPD lung and offer insights for development of precision-based treatment to halt lung destruction. 10.1152/physrev.00036.2021
Alveolar epithelial regeneration in the aging lung. The Journal of clinical investigation Advancing age is the most important risk factor for the development of and mortality from acute and chronic lung diseases, including pneumonia, chronic obstructive pulmonary disease, and pulmonary fibrosis. This risk was manifest during the COVID-19 pandemic, when elderly people were disproportionately affected and died from SARS-CoV-2 pneumonia. However, the recent pandemic also provided lessons on lung resilience. An overwhelming majority of patients with SARS-CoV-2 pneumonia, even those with severe disease, recovered with near-complete restoration of lung architecture and function. These observations are inconsistent with historic views of the lung as a terminally differentiated organ incapable of regeneration. Here, we review emerging hypotheses that explain how the lung repairs itself after injury and why these mechanisms of lung repair fail in some individuals, particularly the elderly. 10.1172/JCI170504
The lung mesenchyme in development, regeneration, and fibrosis. The Journal of clinical investigation Mesenchymal cells are uniquely located at the interface between the epithelial lining and the stroma, allowing them to act as a signaling hub among diverse cellular compartments of the lung. During embryonic and postnatal lung development, mesenchyme-derived signals instruct epithelial budding, branching morphogenesis, and subsequent structural and functional maturation. Later during adult life, the mesenchyme plays divergent roles wherein its balanced activation promotes epithelial repair after injury while its aberrant activation can lead to pathological remodeling and fibrosis that are associated with multiple chronic pulmonary diseases, including bronchopulmonary dysplasia, idiopathic pulmonary fibrosis, and chronic obstructive pulmonary disease. In this Review, we discuss the involvement of the lung mesenchyme in various morphogenic, neomorphogenic, and dysmorphogenic aspects of lung biology and health, with special emphasis on lung fibroblast subsets and smooth muscle cells, intercellular communication, and intrinsic mesenchymal mechanisms that drive such physiological and pathophysiological events throughout development, homeostasis, injury repair, regeneration, and aging. 10.1172/JCI170498
Confronting COVID-19-associated cough and the post-COVID syndrome: role of viral neurotropism, neuroinflammation, and neuroimmune responses. The Lancet. Respiratory medicine Cough is one of the most common presenting symptoms of COVID-19, along with fever and loss of taste and smell. Cough can persist for weeks or months after SARS-CoV-2 infection, often accompanied by chronic fatigue, cognitive impairment, dyspnoea, or pain-a collection of long-term effects referred to as the post-COVID syndrome or long COVID. We hypothesise that the pathways of neurotropism, neuroinflammation, and neuroimmunomodulation through the vagal sensory nerves, which are implicated in SARS-CoV-2 infection, lead to a cough hypersensitivity state. The post-COVID syndrome might also result from neuroinflammatory events in the brain. We highlight gaps in understanding of the mechanisms of acute and chronic COVID-19-associated cough and post-COVID syndrome, consider potential ways to reduce the effect of COVID-19 by controlling cough, and suggest future directions for research and clinical practice. Although neuromodulators such as gabapentin or opioids might be considered for acute and chronic COVID-19 cough, we discuss the possible mechanisms of COVID-19-associated cough and the promise of new anti-inflammatories or neuromodulators that might successfully target both the cough of COVID-19 and the post-COVID syndrome. 10.1016/S2213-2600(21)00125-9
HIV-associated lung disease. Nature reviews. Disease primers Lung disease encompasses acute, infectious processes and chronic, non-infectious processes such as chronic obstructive pulmonary disease, asthma and lung cancer. People living with HIV are at increased risk of both acute and chronic lung diseases. Although the use of effective antiretroviral therapy has diminished the burden of infectious lung disease, people living with HIV experience growing morbidity and mortality from chronic lung diseases. A key risk factor for HIV-associated lung disease is cigarette smoking, which is more prevalent in people living with HIV than in uninfected people. Other risk factors include older age, history of bacterial pneumonia, Pneumocystis pneumonia, pulmonary tuberculosis and immunosuppression. Mechanistic investigations support roles for aberrant innate and adaptive immunity, local and systemic inflammation, oxidative stress, altered lung and gut microbiota, and environmental exposures such as biomass fuel burning in the development of HIV-associated lung disease. Assessment, prevention and treatment strategies are largely extrapolated from data from HIV-uninfected people. Smoking cessation is essential. Data on the long-term consequences of HIV-associated lung disease are limited. Efforts to continue quantifying the effects of HIV infection on the lung, especially in low-income and middle-income countries, are essential to advance our knowledge and optimize respiratory care in people living with HIV. 10.1038/s41572-023-00450-5
Treatment Trials in Young Patients with Chronic Obstructive Pulmonary Disease and Pre-Chronic Obstructive Pulmonary Disease Patients: Time to Move Forward. American journal of respiratory and critical care medicine Chronic obstructive pulmonary disease (COPD) is the end result of a series of dynamic and cumulative gene-environment interactions over a lifetime. The evolving understanding of COPD biology provides novel opportunities for prevention, early diagnosis, and intervention. To advance these concepts, we propose therapeutic trials in two major groups of subjects: "young" individuals with COPD and those with pre-COPD. Given that lungs grow to about 20 years of age and begin to age at approximately 50 years, we consider "young" patients with COPD those patients in the age range of 20-50 years. Pre-COPD relates to individuals of any age who have respiratory symptoms with or without structural and/or functional abnormalities, in the absence of airflow limitation, and who may develop persistent airflow limitation over time. We exclude from the current discussion infants and adolescents because of their unique physiological context and COPD in older adults given their representation in prior randomized controlled trials (RCTs). We highlight the need of RCTs focused on COPD in young patients or pre-COPD to reduce disease progression, providing innovative approaches to identifying and engaging potential study subjects. We detail approaches to RCT design, including potential outcomes such as lung function, patient-reported outcomes, exacerbations, lung imaging, mortality, and composite endpoints. We critically review study design components such as statistical powering and analysis, duration of study treatment, and formats to trial structure, including platform, basket, and umbrella trials. We provide a call to action for treatment RCTs in ) young adults with COPD and ) those with pre-COPD at any age. 10.1164/rccm.202107-1663SO
Update on Clinical Aspects of Chronic Obstructive Pulmonary Disease. Celli Bartolomé R,Wedzicha Jadwiga A The New England journal of medicine 10.1056/NEJMra1900500
Respiratory sequelae of COVID-19: pulmonary and extrapulmonary origins, and approaches to clinical care and rehabilitation. The Lancet. Respiratory medicine Although the exact prevalence of post-COVID-19 condition (also known as long COVID) is unknown, more than a third of patients with COVID-19 develop symptoms that persist for more than 3 months after SARS-CoV-2 infection. These sequelae are highly heterogeneous in nature and adversely affect multiple biological systems, although breathlessness is a frequently cited symptom. Specific pulmonary sequelae, including pulmonary fibrosis and thromboembolic disease, need careful assessment and might require particular investigations and treatments. COVID-19 outcomes in people with pre-existing respiratory conditions vary according to the nature and severity of the respiratory disease and how well it is controlled. Extrapulmonary complications such as reduced exercise tolerance and frailty might contribute to breathlessness in post-COVID-19 condition. Non-pharmacological therapeutic options, including adapted pulmonary rehabilitation programmes and physiotherapy techniques for breathing management, might help to attenuate breathlessness in people with post-COVID-19 condition. Further research is needed to understand the origins and course of respiratory symptoms and to develop effective therapeutic and rehabilitative strategies. 10.1016/S2213-2600(23)00159-5
Pharmacology and Therapeutics of Bronchodilators Revisited. Matera M G,Page C P,Calzetta L,Rogliani P,Cazzola M Pharmacological reviews Bronchodilators remain the cornerstone of the treatment of airway disorders such as asthma and chronic obstructive pulmonary disease (COPD). There is therefore considerable interest in understanding how to optimize the use of our existing classes of bronchodilator and in identifying novel classes of bronchodilator drugs. However, new classes of bronchodilator have proved challenging to develop because many of these have no better efficacy than existing classes of bronchodilator and often have unacceptable safety profiles. Recent research has shown that optimization of bronchodilation occurs when both arms of the autonomic nervous system are affected through antagonism of muscarinic receptors to reduce the influence of parasympathetic innervation of the lung and through stimulation of -adrenoceptors ( -ARs) on airway smooth muscle with -AR-selective agonists to mimic the sympathetic influence on the lung. This is currently achieved by use of fixed-dose combinations of inhaled long-acting -adrenoceptor agonists (LABAs) and long-acting muscarinic acetylcholine receptor antagonists (LAMAs). Due to the distinct mechanisms of action of LAMAs and LABAs, the additive/synergistic effects of using these drug classes together has been extensively investigated. More recently, so-called "triple inhalers" containing fixed-dose combinations of both classes of bronchodilator (dual bronchodilation) and an inhaled corticosteroid in the same inhaler have been developed. Furthermore, a number of so-called "bifunctional drugs" having two different primary pharmacological actions in the same molecule are under development. This review discusses recent advancements in knowledge on bronchodilators and bifunctional drugs for the treatment of asthma and COPD. SIGNIFICANCE STATEMENT: Since our last review in 2012, there has been considerable research to identify novel classes of bronchodilator drugs, to further understand how to optimize the use of the existing classes of bronchodilator, and to better understand the role of bifunctional drugs in the treatment of asthma and chronic obstructive pulmonary disease. 10.1124/pr.119.018150
Targeting Type 2 Inflammation and Epithelial Alarmins in Chronic Obstructive Pulmonary Disease: A Biologics Outlook. American journal of respiratory and critical care medicine Chronic obstructive pulmonary disease (COPD) is a complex, heterogeneous, progressive inflammatory airway disease associated with a significant impact on patients' lives, including morbidity and mortality, and significant healthcare costs. Current pharmacologic strategies, including first- and second-line therapies such as long-acting β-agonists, long-acting muscarinic antagonists, inhaled corticosteroids, phosphodiesterase-4 inhibitors, and macrolides, provide relief to patients with COPD. However, many patients remain symptomatic, with persistent symptoms and/or acute exacerbations and progressive lung function loss. Although neutrophilic inflammation is the most common type of inflammation in COPD, 20-40% of patients with COPD exhibit type 2 inflammation, with roles for CD4 (cluster of differentiation 4) T-helper cell type 1 cells, type 2 innate lymphoid cells, eosinophils, and alternatively activated macrophages. On the basis of the current limitations of available therapies, a significant unmet need exists in COPD management, including the need for targeted therapies to address the underlying pathophysiology leading to disease progression, such as type 2 inflammation, as well as biomarkers to help select the patients who would most benefit from the new therapies. Significant progress is being made, with evolving understanding of the pathobiology of COPD leading to novel therapeutic targets including epithelial alarmins. In this review, we describe the current therapeutic landscape in COPD, discuss unmet treatment needs, review the current knowledge of type 2 inflammation and epithelial alarmins in COPD, explore potential biomarkers of type 2 inflammation in COPD, and finally provide a rationale for incorporating therapies targeting type 2 inflammation and epithelial alarmins in COPD. available online at www.atsjournals.org. 10.1164/rccm.202303-0455CI
Diagnosis and Outpatient Management of Chronic Obstructive Pulmonary Disease: A Review. JAMA IMPORTANCE:There are 30 million adults (12%) in the United States who have chronic obstructive pulmonary disease (COPD). Chronic obstructive pulmonary disease accounts for 3.2% of all physician office visits annually and is the fourth leading cause of death (126 000 deaths per year). Most patients are diagnosed by their primary care clinicians who must address the highly variable clinical features and responses to therapy. The diagnosis and treatment of COPD is rapidly changing, so understanding recent advances is important for the delivery of optimal patient care. OBSERVATIONS:Chronic obstructive pulmonary disease is characterized by incompletely reversible expiratory airflow limitation. Spirometry is the reference standard for diagnosing and assessing the severity of COPD. All patients should be counseled about and receive preventive measures such as smoking cessation and vaccination. Treatment should be guided by the severity of lung impairment, symptoms such as dyspnea, the amount of cough and sputum production, and how often a patient experiences an exacerbation. When dyspnea limits activity or quality of life, COPD should be treated with once- or twice-daily maintenance long-acting anticholinergic and β-agonist bronchodilators. Patients with acute exacerbations may benefit from the addition of inhaled corticosteroids, particularly those with elevated peripheral eosinophil levels. Pulmonary rehabilitation, which includes strength and endurance training and educational, nutritional, and psychosocial support, improves symptoms and exercise tolerance but is underutilized. Supplemental oxygen for patients with resting hypoxemia (defined as Spo2 <89%) improves survival. CONCLUSIONS AND RELEVANCE:Chronic obstructive pulmonary disease is a complicated disease requiring intensive treatment. Appropriate use of long-acting maintenance bronchodilators, inhaled corticosteroids, and pulmonary rehabilitation decreases symptoms, optimizes functional performance, and reduces exacerbation frequency. Supplemental oxygen in patients with resting hypoxemia prolongs life, and other advanced treatments are available based on specific patient characteristics. 10.1001/jama.2019.0131
Lung volume reduction for emphysema. Shah Pallav L,Herth Felix J,van Geffen Wouter H,Deslee Gaetan,Slebos Dirk-Jan The Lancet. Respiratory medicine Advanced emphysema is a lung disease in which alveolar capillary units are destroyed and supporting tissue is lost. The combined effect of reduced gas exchange and changes in airway dynamics impairs expiratory airflow and leads to progressive air trapping. Pharmacological therapies have limited effects. Surgical resection of the most destroyed sections of the lung can improve pulmonary function and exercise capacity but its benefit is tempered by significant morbidity. This issue stimulated a search for novel approaches to lung volume reduction. Alternative minimally invasive approaches using bronchoscopic techniques including valves, coils, vapour thermal ablation, and sclerosant agents have been at the forefront of these developments. Insertion of endobronchial valves in selected patients could have benefits that are comparable with lung volume reduction surgery. Endobronchial coils might have a role in the treatment of patients with emphysema with severe hyperinflation and less parenchymal destruction. Use of vapour thermal energy or a sclerosant might allow focal treatment but the unpredictability of the inflammatory response limits their current use. In this Review, we aim to summarise clinical trial evidence on lung volume reduction and provide guidance on patient selection for available therapies. 10.1016/S2213-2600(16)30221-1
Cellular Senescence as a Mechanism and Target in Chronic Lung Diseases. Barnes Peter J,Baker Jonathan,Donnelly Louise E American journal of respiratory and critical care medicine Cellular senescence is now considered an important driving mechanism for chronic lung diseases, particularly chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis. Cellular senescence is due to replicative and stress-related senescence with activation of p53 and p16, respectively, leading to activation of p21 and cell cycle arrest. Senescent cells secrete multiple inflammatory proteins known as the senescence-associated secretory phenotype, leading to low-grade chronic inflammation, which further drives senescence. Loss of key antiaging molecules sirtuin-1 and sirtuin-6 may be important in acceleration of aging and arises from oxidative stress reducing phosphatase PTEN (phosphatase tensin homolog), thereby activating PI3K (phosphoinositide-3-kinase) and mTOR (mammalian target of rapamycin). MicroRNA-34a (miR-34a), which is regulated by PI3K-mTOR signaling, plays a pivotal role in reducing sirtuin-1/6, and its inhibition with an antagomir results in their restoration, reducing markers of senescence, reducing senescence-associated secretory phenotype, and reversing cell cycle arrest in epithelial cells from peripheral airways of patients with COPD. miR-570 is also involved in reduction of sirtuin-1 and cellular senescence and is activated by p38 mitogen-activated protein kinase. These miRNAs may be released from cells in extracellular vesicles that are taken up by other cells, thereby spreading senescence locally within the lung but also outside the lung through the circulation; this may account for comorbidities of COPD and other lung diseases. Understanding the mechanisms of cellular senescence may result in new treatments for chronic lung disease, either by inhibiting PI3K-mTOR signaling, by inhibiting specific miRNAs, or by deletion of senescent cells with senolytic therapies, already shown to be effective in experimental lung fibrosis. 10.1164/rccm.201810-1975TR
Clonal haematopoiesis and dysregulation of the immune system. Nature reviews. Immunology Age-related diseases are frequently linked to pathological immune dysfunction, including excessive inflammation, autoreactivity and immunodeficiency. Recent analyses of human genetic data have revealed that somatic mutations and mosaic chromosomal alterations in blood cells - a condition known as clonal haematopoiesis (CH) - are associated with ageing and pathological immune dysfunction. Indeed, large-scale epidemiological studies and experimental mouse models have demonstrated that CH can promote cardiovascular disease, chronic obstructive pulmonary disease, chronic liver disease, osteoporosis and gout. The genes most frequently mutated in CH, the epigenetic regulators TET2 and DNMT3A, implicate increased chemokine expression and inflammasome hyperactivation in myeloid cells as a possible mechanistic connection between CH and age-related diseases. In addition, TET2 and DNMT3A mutations in lymphoid cells have been shown to drive methylation-dependent alterations in differentiation and function. Here we review the observational and mechanistic studies describing the connection between CH and pathological immune dysfunction, the effects of CH-associated genetic alterations on the function of myeloid and lymphoid cells, and the clinical and therapeutic implications of CH as a target for immunomodulation. 10.1038/s41577-023-00843-3
Functional effects of the microbiota in chronic respiratory disease. The Lancet. Respiratory medicine The composition of the lung microbiome is increasingly well characterised, with changes in microbial diversity or abundance observed in association with several chronic respiratory diseases such as asthma, cystic fibrosis, bronchiectasis, and chronic obstructive pulmonary disease. However, the precise effects of the microbiome on pulmonary health and the functional mechanisms by which it regulates host immunity are only now beginning to be elucidated. Bacteria, viruses, and fungi from both the upper and lower respiratory tract produce structural ligands and metabolites that interact with the host and alter the development and progression of chronic respiratory diseases. Here, we review recent advances in our understanding of the composition of the lung microbiome, including the virome and mycobiome, the mechanisms by which these microbes interact with host immunity, and their functional effects on the pathogenesis, exacerbations, and comorbidities of chronic respiratory diseases. We also describe the present understanding of how respiratory microbiota can influence the efficacy of common therapies for chronic respiratory disease, and the potential of manipulation of the microbiome as a therapeutic strategy. Finally, we highlight some of the limitations in the field and propose how these could be addressed in future research. 10.1016/S2213-2600(18)30510-1
Genetics of COPD. Silverman Edwin K Annual review of physiology Although chronic obstructive pulmonary disease (COPD) risk is strongly influenced by cigarette smoking, genetic factors are also important determinants of COPD. In addition to Mendelian syndromes such as alpha-1 antitrypsin deficiency, many genomic regions that influence COPD susceptibility have been identified in genome-wide association studies. Similarly, multiple genomic regions associated with COPD-related phenotypes, such as quantitative emphysema measures, have been found. Identifying the functional variants and key genes within these association regions remains a major challenge. However, newly identified COPD susceptibility genes are already providing novel insights into COPD pathogenesis. Network-based approaches that leverage these genetic discoveries have the potential to assist in decoding the complex genetic architecture of COPD. 10.1146/annurev-physiol-021317-121224
Pathogenesis of chronic obstructive pulmonary disease: understanding the contributions of gene-environment interactions across the lifespan. The Lancet. Respiratory medicine The traditional view of chronic obstructive pulmonary disease (COPD) as a self-inflicted disease caused by tobacco smoking in genetically susceptible individuals has been challenged by recent research findings. COPD can instead be understood as the potential end result of the accumulation of gene-environment interactions encountered by an individual over the life course. Integration of a time axis in pathogenic models of COPD is necessary because the biological responses to and clinical consequences of different exposures might vary according to both the age of an individual at which a given gene-environment interaction occurs and the cumulative history of previous gene-environment interactions. Future research should aim to understand the effects of dynamic interactions between genes (G) and the environment (E) by integrating information from basic omics (eg, genomics, epigenomics, proteomics) and clinical omics (eg, phenomics, physiomics, radiomics) with exposures (the exposome) over time (T)-an approach that we refer to as GETomics. In the context of this approach, we argue that COPD should be viewed not as a single disease, but as a clinical syndrome characterised by a recognisable pattern of chronic symptoms and structural or functional impairments due to gene-environment interactions across the lifespan that influence normal lung development and ageing. 10.1016/S2213-2600(21)00555-5
Appropriate Use of Short-Course Antibiotics in Common Infections: Best Practice Advice From the American College of Physicians. Lee Rachael A,Centor Robert M,Humphrey Linda L,Jokela Janet A,Andrews Rebecca,Qaseem Amir, ,Akl Elie A.,Bledsoe Thomas A.,Forciea Mary Ann,Haeme Ray,Kansagara Devan L.,Marcucci Maura,Miller Matthew C.,Obley Adam J. Annals of internal medicine DESCRIPTION:Antimicrobial overuse is a major health care issue that contributes to antibiotic resistance. Such overuse includes unnecessarily long durations of antibiotic therapy in patients with common bacterial infections, such as acute bronchitis with chronic obstructive pulmonary disease (COPD) exacerbation, community-acquired pneumonia (CAP), urinary tract infections (UTIs), and cellulitis. This article describes best practices for prescribing appropriate and short-duration antibiotic therapy for patients presenting with these infections. METHODS:The authors conducted a narrative literature review of published clinical guidelines, systematic reviews, and individual studies that addressed bronchitis with COPD exacerbations, CAP, UTIs, and cellulitis. This article is based on the best available evidence but was not a formal systematic review. Guidance was prioritized to the highest available level of synthesized evidence. BEST PRACTICE ADVICE 1: BEST PRACTICE ADVICE 2: BEST PRACTICE ADVICE 3: BEST PRACTICE ADVICE 4: 10.7326/M20-7355
Global Initiative for the Diagnosis, Management, and Prevention of Chronic Obstructive Lung Disease. The 2020 GOLD Science Committee Report on COVID-19 and Chronic Obstructive Pulmonary Disease. American journal of respiratory and critical care medicine The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has raised many questions about the management of patients with chronic obstructive pulmonary disease (COPD) and whether modifications of their therapy are required. It has raised questions about recognizing and differentiating coronavirus disease (COVID-19) from COPD given the similarity of the symptoms. The Global Initiative for Chronic Obstructive Lung Disease (GOLD) Science Committee used established methods for literature review to present an overview of the management of patients with COPD during the COVID-19 pandemic. It is unclear whether patients with COPD are at increased risk of becoming infected with SARS-CoV-2. During periods of high community prevalence of COVID-19, spirometry should only be used when it is essential for COPD diagnosis and/or to assess lung function status for interventional procedures or surgery. Patients with COPD should follow basic infection control measures, including social distancing, hand washing, and wearing a mask or face covering. Patients should remain up to date with appropriate vaccinations, particularly annual influenza vaccination. Although data are limited, inhaled corticosteroids, long-acting bronchodilators, roflumilast, or chronic macrolides should continue to be used as indicated for stable COPD management. Systemic steroids and antibiotics should be used in COPD exacerbations according to the usual indications. Differentiating symptoms of COVID-19 infection from chronic underlying symptoms or those of an acute COPD exacerbation may be challenging. If there is suspicion for COVID-19, testing for SARS-CoV-2 should be considered. Patients who developed moderate-to-severe COVID-19, including hospitalization and pneumonia, should be treated with evolving pharmacotherapeutic approaches as appropriate, including remdesivir, dexamethasone, and anticoagulation. Managing acute respiratory failure should include appropriate oxygen supplementation, prone positioning, noninvasive ventilation, and protective lung strategy in patients with COPD and severe acute respiratory distress syndrome. Patients who developed asymptomatic or mild COVID-19 should be followed with the usual COPD protocols. Patients who developed moderate or worse COVID-19 should be monitored more frequently and accurately than the usual patients with COPD, with particular attention to the need for oxygen therapy. 10.1164/rccm.202009-3533SO
Physiology and pathophysiology of human airway mucus. Physiological reviews The mucus clearance system is the dominant mechanical host defense system of the human lung. Mucus is cleared from the lung by cilia and airflow, including both two-phase gas-liquid pumping and cough-dependent mechanisms, and mucus transport rates are heavily dependent on mucus concentration. Importantly, mucus transport rates are accurately predicted by the gel-on-brush model of the mucociliary apparatus from the relative osmotic moduli of the mucus and periciliary-glycocalyceal (PCL-G) layers. The fluid available to hydrate mucus is generated by transepithelial fluid transport. Feedback interactions between mucus concentrations and cilia beating, via purinergic signaling, coordinate Na absorptive vs Cl secretory rates to maintain mucus hydration in health. In disease, mucus becomes hyperconcentrated (dehydrated). Multiple mechanisms derange the ion transport pathways that normally hydrate mucus in muco-obstructive lung diseases, e.g., cystic fibrosis (CF), chronic obstructive pulmonary disease (COPD), non-CF bronchiectasis (NCFB), and primary ciliary dyskinesia (PCD). A key step in muco-obstructive disease pathogenesis is the osmotic compression of the mucus layer onto the airway surface with the formation of adherent mucus plaques and plugs, particularly in distal airways. Mucus plaques create locally hypoxic conditions and produce airflow obstruction, inflammation, infection, and, ultimately, airway wall damage. Therapies to clear adherent mucus with hydrating and mucolytic agents are rational, and strategies to develop these agents are reviewed. 10.1152/physrev.00004.2021
COPD and multimorbidity: recognising and addressing a syndemic occurrence. The Lancet. Respiratory medicine Most patients with chronic obstructive pulmonary disease (COPD) have at least one additional, clinically relevant chronic disease. Those with the most severe airflow obstruction will die from respiratory failure, but most patients with COPD die from non-respiratory disorders, particularly cardiovascular diseases and cancer. As many chronic diseases have shared risk factors (eg, ageing, smoking, pollution, inactivity, and poverty), we argue that a shift from the current paradigm in which COPD is considered as a single disease with comorbidities, to one in which COPD is considered as part of a multimorbid state-with co-occurring diseases potentially sharing pathobiological mechanisms-is needed to advance disease prevention, diagnosis, and management. The term syndemics is used to describe the co-occurrence of diseases with shared mechanisms and risk factors, a novel concept that we propose helps to explain the clustering of certain morbidities in patients diagnosed with COPD. A syndemics approach to understanding COPD could have important clinical implications, in which the complex disease presentations in these patients are addressed through proactive diagnosis, assessment of severity, and integrated management of the COPD multimorbid state, with a patient-centred rather than a single-disease approach. 10.1016/S2213-2600(23)00261-8
Chronic obstructive pulmonary disease. Rabe Klaus F,Watz Henrik Lancet (London, England) Chronic obstructive pulmonary disease (COPD) kills more than 3 million people worldwide every year. Despite progress in the treatment of symptoms and prevention of acute exacerbations, few advances have been made to ameliorate disease progression or affect mortality. A better understanding of the complex disease mechanisms resulting in COPD is needed. Smoking cessation programmes, increasing physical activity, and early detection and treatment of comorbidities are further key components to reduce the burden of the disease. However, without a global political and economic effort to reduce tobacco use, to regulate environmental exposure, and to find alternatives to the massive use of biomass fuel, COPD will remain a major health-care problem for decades to come. 10.1016/S0140-6736(17)31222-9
Mitochondria in health, disease, and aging. Physiological reviews Mitochondria are well known as organelles responsible for the maintenance of cellular bioenergetics through the production of ATP. Although oxidative phosphorylation may be their most important function, mitochondria are also integral for the synthesis of metabolic precursors, calcium regulation, the production of reactive oxygen species, immune signaling, and apoptosis. Considering the breadth of their responsibilities, mitochondria are fundamental for cellular metabolism and homeostasis. Appreciating this significance, translational medicine has begun to investigate how mitochondrial dysfunction can represent a harbinger of disease. In this review, we provide a detailed overview of mitochondrial metabolism, cellular bioenergetics, mitochondrial dynamics, autophagy, mitochondrial damage-associated molecular patterns, mitochondria-mediated cell death pathways, and how mitochondrial dysfunction at any of these levels is associated with disease pathogenesis. Mitochondria-dependent pathways may thereby represent an attractive therapeutic target for ameliorating human disease. 10.1152/physrev.00058.2021
Towards the elimination of chronic obstructive pulmonary disease: a Lancet Commission. Lancet (London, England) 10.1016/S0140-6736(22)01273-9
Pulmonary Hypertension. Poch David,Mandel Jess Annals of internal medicine Pulmonary hypertension is the term used to describe a group of disorders characterized by abnormally high pressures in the pulmonary arteries. Initial evaluation is focused on identifying the cause, which helps guide appropriate treatment. Pulmonary hypertension is often a feature of advanced common diseases, such as chronic obstructive pulmonary disease and left heart disease, and treatment is focused primarily on the underlying disease. More rarely, pulmonary hypertension results from chronic organized thromboemboli or a primary vasculopathy. The former requires evaluation for surgical intervention, and the latter is treated with advanced medical therapies. 10.7326/AITC202104200
Aging and Lung Disease. Cho Soo Jung,Stout-Delgado Heather W Annual review of physiology People worldwide are living longer, and it is estimated that by 2050, the proportion of the world's population over 60 years of age will nearly double. Natural lung aging is associated with molecular and physiological changes that cause alterations in lung function, diminished pulmonary remodeling and regenerative capacity, and increased susceptibility to acute and chronic lung diseases. As the aging population rapidly grows, it is essential to examine how alterations in cellular function and cell-to-cell interactions of pulmonary resident cells and systemic immune cells contribute to a higher risk of increased susceptibility to infection and development of chronic diseases, such as chronic obstructive pulmonary disease and interstitial pulmonary fibrosis. This review provides an overview of physiological, structural, and cellular changes in the aging lung and immune system that facilitate the development and progression of disease. 10.1146/annurev-physiol-021119-034610
The aging lung: Physiology, disease, and immunity. Cell The population is aging at a rate never seen before in human history. As the number of elderly adults grows, it is imperative we expand our understanding of the underpinnings of aging biology. Human lungs are composed of a unique panoply of cell types that face ongoing chemical, mechanical, biological, immunological, and xenobiotic stress over a lifetime. Yet, we do not fully appreciate the mechanistic drivers of lung aging and why age increases the risk of parenchymal lung disease, fatal respiratory infection, and primary lung cancer. Here, we review the molecular and cellular aspects of lung aging, local stress response pathways, and how the aging process predisposes to the pathogenesis of pulmonary disease. We place these insights into context of the COVID-19 pandemic and discuss how innate and adaptive immunity within the lung is altered with age. 10.1016/j.cell.2021.03.005
Targeting oxidative stress in disease: promise and limitations of antioxidant therapy. Nature reviews. Drug discovery Oxidative stress is a component of many diseases, including atherosclerosis, chronic obstructive pulmonary disease, Alzheimer disease and cancer. Although numerous small molecules evaluated as antioxidants have exhibited therapeutic potential in preclinical studies, clinical trial results have been disappointing. A greater understanding of the mechanisms through which antioxidants act and where and when they are effective may provide a rational approach that leads to greater pharmacological success. Here, we review the relationships between oxidative stress, redox signalling and disease, the mechanisms through which oxidative stress can contribute to pathology, how antioxidant defences work, what limits their effectiveness and how antioxidant defences can be increased through physiological signalling, dietary components and potential pharmaceutical intervention. 10.1038/s41573-021-00233-1
Chronic Obstructive Pulmonary Disease. Labaki Wassim W,Rosenberg Sharon R Annals of internal medicine Chronic obstructive pulmonary disease (COPD) is characterized by persistent respiratory symptoms and progressive airflow obstruction. Tobacco smoking is the leading cause but not the only one. A postbronchodilator FEV-FVC ratio less than 0.70 is required for a diagnosis of COPD. Inhaler therapy is the backbone of treatment and should be complemented by a multifaceted management strategy that includes counseling and pharmacotherapy for smoking cessation, pulmonary rehabilitation, treatment of comorbidities, administration of influenza and pneumococcal immunizations, and prescription of long-term oxygen therapy in hypoxemic patients. 10.7326/AITC202008040
Chronic obstructive pulmonary disease in never-smokers: risk factors, pathogenesis, and implications for prevention and treatment. The Lancet. Respiratory medicine Chronic obstructive pulmonary disease (COPD) was traditionally thought to be caused by tobacco smoking. However, recognition of the importance of non-smoking-related risk factors for COPD has increased over the past decade, with evidence on the burden, risk factors, and clinical presentations of COPD in never-smokers. About half of all COPD cases worldwide are due to non-tobacco-related risk factors, which vary by geographical region. These factors include air pollution, occupational exposures, poorly controlled asthma, environmental tobacco smoke, infectious diseases, and low socioeconomic status. Impaired lung growth during childhood, caused by a range of early-life exposures, is associated with an increased risk of COPD. Potential mechanisms for the pathogenesis of COPD in never-smokers include inflammation, oxidative stress, airway remodelling, and accelerated lung ageing. Compared with smokers who develop COPD, never-smokers with COPD have relatively mild chronic respiratory symptoms, little or no emphysema, milder airflow limitation, and fewer comorbidities; however, exacerbations can still be frequent. Further research-including epidemiological, translational, clinical, and implementation studies-is needed to address gaps in understanding and to advance potential solutions to reduce the burden of COPD in never-smokers. 10.1016/S2213-2600(21)00506-3
The Bidirectional Gut-Lung Axis in Chronic Obstructive Pulmonary Disease. American journal of respiratory and critical care medicine Epidemiological studies indicate that chronic obstructive pulmonary disease (COPD) is associated with the incidence of changes in intestinal health. Cigarette smoking, as one of the major causes of COPD, can have an impact on the gastrointestinal system and promotes intestinal diseases. This points to the existence of gut-lung interactions, but an overview of the underlying mechanisms of the bidirectional connection between the lungs and the gut in COPD is lacking. The interaction between the lungs and the gut can occur through circulating inflammatory cells and mediators. Moreover, gut microbiota dysbiosis, observed in both COPD and intestinal disorders, can lead to a disturbed mucosal environment, including the intestinal barrier and immune system, and hence may negatively affect both the gut and the lungs. Furthermore, systemic hypoxia and oxidative stress that occur in COPD may also be involved in intestinal dysfunction and play a role in the gut-lung axis. In this review, we summarize data from clinical research, animal models, and studies that may explain the possible mechanisms of gut-lung interactions associated with COPD. Interesting observations on the possibility of promising future add-on therapies for intestinal dysfunction in patients with COPD are highlighted. 10.1164/rccm.202206-1066TR
Advances in Chronic Obstructive Pulmonary Disease. Annual review of medicine Chronic obstructive pulmonary disease (COPD) is a common respiratory disorder with significant morbidity and mortality. Despite its prevalence, COPD is underdiagnosed, and many patients do not receive a diagnosis until the disease is clinically advanced. Recent basic science and clinical research have focused on the early physiologic and pathobiologic changes in COPD with the hopes of improving diagnosis, providing targets for disease-modifying therapy, and identifying patients most likely to benefit from early intervention. Available treatments for COPD have grown substantially in the past 20 years with the introduction of new oral and inhaled medications as well as novel surgical and bronchoscopic procedures. This article summarizes some of the recent advances in our understanding of disease pathogenesis and treatment paradigms. 10.1146/annurev-med-080919-112707