Smoking-induced skeletal muscle dysfunction: from evidence to mechanisms.
Degens Hans,Gayan-Ramirez Ghislaine,van Hees Hieronymus W H
American journal of respiratory and critical care medicine
Smoking is the most important risk factor for the development of chronic obstructive pulmonary disease (COPD). Patients with COPD commonly suffer from skeletal muscle dysfunction, and it has been suggested that cigarette smoke exposure contributes to the development of skeletal muscle dysfunction even before overt pulmonary pathology. This review summarizes the evidence that muscles of nonsymptomatic smokers are weaker and less fatigue resistant than those of nonsmokers. Although physical inactivity of many smokers contributes to some alterations observed in skeletal muscle, exposure to cigarette smoke per se can also induce skeletal muscle dysfunction. Cigarette smoke constituents and systemic inflammatory mediators enhance proteolysis and inhibit protein synthesis, leading to loss of muscle mass. Reduced skeletal muscle contractile endurance in smokers may result from impaired oxygen delivery to the mitochondria and ability of the mitochondria to generate ATP due to interaction of carbon monoxide with hemoglobin, myoglobin, and components of the respiratory chain. Besides hampering contractile function, smoking may have immediate beneficial effects on motor skills, which are attributable to nicotine. In contrast to pulmonary pathology, many of the effects of smoking on skeletal muscle are most likely reversible by smoking cessation.
10.1164/rccm.201410-1830PP
Bacterial Outer Membrane Vesicles Mediate Cytosolic Localization of LPS and Caspase-11 Activation.
Vanaja Sivapriya Kailasan,Russo Ashley J,Behl Bharat,Banerjee Ishita,Yankova Maya,Deshmukh Sachin D,Rathinam Vijay A K
Cell
Sensing of lipopolysaccharide (LPS) in the cytosol triggers caspase-11 activation and is central to host defense against Gram-negative bacterial infections and to the pathogenesis of sepsis. Most Gram-negative bacteria that activate caspase-11, however, are not cytosolic, and the mechanism by which LPS from these bacteria gains access to caspase-11 in the cytosol remains elusive. Here, we identify outer membrane vesicles (OMVs) produced by Gram-negative bacteria as a vehicle that delivers LPS into the cytosol triggering caspase-11-dependent effector responses in vitro and in vivo. OMVs are internalized via endocytosis, and LPS is released into the cytosol from early endosomes. The use of hypovesiculating bacterial mutants, compromised in their ability to generate OMVs, reveals the importance of OMVs in mediating the cytosolic localization of LPS. Collectively, these findings demonstrate a critical role for OMVs in enabling the cytosolic entry of LPS and, consequently, caspase-11 activation during Gram-negative bacterial infections.
10.1016/j.cell.2016.04.015
Porin Loss Impacts the Host Inflammatory Response to Outer Membrane Vesicles of Klebsiella pneumoniae.
Turner Kelli L,Cahill Bethaney K,Dilello Sarah K,Gutel Dedra,Brunson Debra N,Albertí Sebastián,Ellis Terri N
Antimicrobial agents and chemotherapy
Antibiotic-resistant strains of Klebsiella pneumoniae often exhibit porin loss. In this study, we investigated how porin loss impacted the composition of secreted outer membrane vesicles as well as their ability to trigger proinflammatory cytokine secretion by macrophages. We hypothesize that porin loss associated with antibiotic resistance will directly impact both the composition of outer membrane vesicles and their interactions with phagocytic cells. Using clonally related clinical isolates of extended-spectrum beta-lactamase (ESBL)-positive Klebsiella pneumoniae with different patterns of porin expression, we demonstrated that altered expression of OmpK35 and OmpK36 results in broad alterations to the protein profile of secreted vesicles. Additionally, the level of OmpA incorporation was elevated in strains lacking a single porin. Porin loss significantly impacted macrophage inflammatory responses to purified vesicles. Outer membrane vesicles lacking both OmpK35 and OmpK36 elicited significantly lower levels of proinflammatory cytokine secretion than vesicles from strains expressing one or both porins. These data demonstrate that antibiotic resistance-associated porin loss has a broad and significant effect on both the composition of outer membrane vesicles and their interactions with phagocytic cells, which may impact bacterial survival and inflammatory reactions in the host.
10.1128/AAC.01627-15
OmpA Protein-Deficient Outer Membrane Vesicles Trigger Reduced Inflammatory Response.
Skerniškytė Jūratė,Karazijaitė Emilija,Lučiūnaitė Asta,Sužiedėlienė Edita
Pathogens (Basel, Switzerland)
Multidrug resistant shows a growing number of nosocomial infections worldwide during the last decade. The outer membrane vesicles (OMVs) produced by this bacterium draw increasing attention as a possible treatment target. OMVs have been implicated in the reduction of antibiotic level in the surrounding environment, transfer of virulence factors into the host cells, and induction of inflammatory response. Although the evidence on the involvement of OMVs in pathogenesis is currently growing, their role during inflammation is insufficiently explored. It is likely that bacteria, by secreting OMVs, can expand the area of their exposure and prepare surrounding matrix for infection. Here, we investigated the impact of OMVs on activation of macrophages in vitro. We show that OmpA protein present in OMVs substantially contributes to the proinflammatory response in J774 murine macrophages and to the cell death in both lung epithelium cells and macrophages. The loss of OmpA protein in OMVs, obtained from ∆ mutant, resulted in the altered expression of genes coding for IL-6, NLRP3 and IL-1β proinflammatory molecules in macrophages in vitro. These results imply that OmpA protein in bacterial OMVs could trigger a more intense proinflammatory response.
10.3390/pathogens10040407
Isolation, characterization and analysis of pro-inflammatory potential of Klebsiella pneumoniae outer membrane vesicles.
Martora Francesca,Pinto Federica,Folliero Veronica,Cammarota Marcella,Dell'Annunziata Federica,Squillaci Giuseppe,Galdiero Massimiliano,Morana Alessandra,Schiraldi Chiara,Giovane Alfonso,Galdiero Marilena,Franci Gianluigi
Microbial pathogenesis
Outer membrane vesicles (OMVs) are potent virulence factors, naturally secreted by gram-negative bacteria. Since Klebsiella pneumoniae has emerged as an important nosocomial pathogen, because of resistance to a wide spectrum of antibiotics, it is crucial to investigate its pathogenetic mechanism microorganism secretes outer membrane vesicles (OMVs), but the pathogenesis of Klebsiella pneumoniae as it relates to OMVs has not been well elucidated. In this study we focused on the isolation, characterization and evaluation of the virulence potential of OMVs obtained from Klebsiella pneumoniae. Our data demonstrate that Klebsiella pneumoniae OMVs are important secretory nanocomplexes that elicit a potent inflammatory response. Since OMVs are clearly involved in the pathogenesis of this bacterium during infection, further studies are required to determine whether they could be future targets for novel therapy and potential vaccine against Klebsiella pneumoniae.
10.1016/j.micpath.2019.103719
Cyclodextrins reduce the ability of Pseudomonas aeruginosa outer-membrane vesicles to reduce CFTR Cl secretion.
Barnaby Roxanna,Koeppen Katja,Stanton Bruce A
American journal of physiology. Lung cellular and molecular physiology
Pseudomonas aeruginosa secretes outer-membrane vesicles (OMVs) that fuse with cholesterol-rich lipid rafts in the apical membrane of airway epithelial cells and decrease wt-CFTR Cl secretion. Herein, we tested the hypothesis that a reduction of the cholesterol content of CF human airway epithelial cells by cyclodextrins reduces the inhibitory effect of OMVs on VX-809 (lumacaftor)-stimulated Phe508del CFTR Cl secretion. Primary CF bronchial epithelial cells and CFBE cells were treated with vehicle, hydroxypropyl-β-cyclodextrin (HPβCD), or methyl-β-cyclodextrin (MβCD), and the effects of OMVs secreted by P. aeruginosa on VX-809 stimulated Phe508del CFTR Cl secretion were measured in Ussing chambers. Neither HPβCD nor MβCD were cytotoxic, and neither altered Phe508del CFTR Cl secretion. Both cyclodextrins reduced OMV inhibition of VX-809-stimulated Phe508del-CFTR Cl secretion when added to the apical side of CF monolayers. Both cyclodextrins also reduced the ability of P. aeruginosa to form biofilms and suppressed planktonic growth of P. aeruginosa. Our data suggest that HPβCD, which is in clinical trials for Niemann-Pick Type C disease, and MβCD, which has been approved by the U.S. Food and Drug Administration for use in solubilizing lipophilic drugs, may enhance the clinical efficacy of VX-809 in CF patients when added to the apical side of airway epithelial cells, and reduce planktonic growth and biofilm formation by P. aeruginosa. Both effects would be beneficial to CF patients.
10.1152/ajplung.00316.2018
Tobramycin reduces key virulence determinants in the proteome of Pseudomonas aeruginosa outer membrane vesicles.
Koeppen Katja,Barnaby Roxanna,Jackson Angelyca A,Gerber Scott A,Hogan Deborah A,Stanton Bruce A
PloS one
Tobramycin is commonly used to treat Pseudomonas aeruginosa lung infections in patients with Cystic Fibrosis (CF). Tobramycin treatment leads to increased lung function and fewer clinical exacerbations in CF patients, and modestly reduces the density of P. aeruginosa in the lungs. P. aeruginosa resides primarily in the mucus overlying lung epithelial cells and secretes outer membrane vesicles (OMVs) that diffuse through the mucus and fuse with airway epithelial cells, thus delivering virulence factors into the cytoplasm that modify the innate immune response. The goal of this study was to test the hypothesis that Tobramycin reduces the abundance of virulence factors in OMVs secreted by P. aeruginosa. Characterization of the proteome of OMVs isolated from control or Tobramycin-exposed P. aeruginosa strain PAO1 revealed that Tobramycin reduced several OMV-associated virulence determinants, including AprA, an alkaline protease that enhances P. aeruginosa survival in the lung, and is predicted to contribute to the inhibitory effect of P. aeruginosa on Phe508del-CFTR Cl- secretion by primary human bronchial epithelial cells. Deletion of the gene encoding AprA reduced the inhibitory effect of P. aeruginosa on Phe508del-CFTR Cl- secretion. Moreover, as predicted by our proteomic analysis, OMVs isolated from Tobramycin treated P. aeruginosa had a diminished inhibitory effect on Phe508del-CFTR Cl- secretion compared to OMVs isolated from control P. aeruginosa. Taken together, our proteomic analysis of OMVs and biological validation suggest that Tobramycin may improve lung function in CF patients infected with P. aeruginosa by reducing several key virulence factors in OMVs that reduce CFTR Cl- secretion, which is essential for bacterial clearance from the lungs.
10.1371/journal.pone.0211290
Hemolytic Membrane Vesicles of Group B Streptococcus Promote Infection.
The Journal of infectious diseases
BACKGROUND:Group B streptococci (GBS) are β-hemolytic, Gram-positive bacteria associated with fetal injury, preterm birth, spontaneous abortion, and neonatal infections. A key factor promoting GBS virulence is the β-hemolysin/cytolysin, a pigmented ornithine rhamnolipid (also known as granadaene) associated with the bacterial surface. METHODS:A previous study indicated that GBS produce small structures known as membrane vesicles (MVs), which contain virulence-associated proteins. In this study, we show that GBS MVs are pigmented and hemolytic, indicating that granadaene is functionally active in MVs. RESULTS:In addition, MVs from hyperhemolytic GBS induced greater cell death of neutrophils, T cells, and B cells compared with MVs from isogenic nonhemolytic GBS, implicating MVs as a potential mechanism for granadaene-mediated virulence. Finally, hemolytic MVs reduced oxidative killing of GBS and aggravated morbidity and mortality of neonatal mice infected with GBS. CONCLUSIONS:These studies, taken together, reveal a novel mechanism by which GBS deploy a crucial virulence factor to promote bacterial dissemination and pathogenesis.
10.1093/infdis/jiaa548
-Derived Outer Membrane Vesicles (OMVs): Role in Bacterial Pathogenesis?
Jarzab Miroslaw,Posselt Gernot,Meisner-Kober Nicole,Wessler Silja
Microorganisms
Persistent infections with the human pathogen () have been closely associated with the induction and progression of a wide range of gastric disorders, including acute and chronic gastritis, ulceration in the stomach and duodenum, mucosa-associated lymphoid tissue (MALT) lymphoma, and gastric adenocarcinoma. The pathogenesis of is determined by a complicated network of manifold mechanisms of pathogen-host interactions, which involves a coordinated interplay of pathogenicity and virulence factors with host cells. While these molecular and cellular mechanisms have been intensively investigated to date, the knowledge about outer membrane vesicles (OMVs) derived from and their implication in bacterial pathogenesis is not well developed. In this review, we summarize the current knowledge on -derived OMVs.
10.3390/microorganisms8091328
Bacterial outer membrane vesicles induce disseminated intravascular coagulation through the caspase-11-gasdermin D pathway.
Peng Yue,Gao Min,Liu Yukun,Qiu Xianhui,Cheng Xiaoye,Yang Xinyu,Chen Fangping,Wang Erhua
Thrombosis research
BACKGROUND:Disseminated intravascular coagulation (DIC), a severe complication of sepsis, promotes multiple organ dysfunctions and lethality. Bacterial infection is the most common cause of sepsis. We previously show an important role of bacteria-released outer membrane vesicles (OMVs) in bacterial infection-induced DIC. In the light of recent advance that activation of caspase-11 and its enzymatic substrate gasdermin D (GSDMD) is able to trigger coagulation, we postulate that OMVs might induce DIC through the caspase-11-GSDMD pathway. METHODS:Caspase-11- or GSDMD-deficient mice and their wild-type (WT) controls were injected with purified Escherichia coli-derived OMVs. Blood samples were then collected. The development of DIC was assessed in terms of the occurrence of coagulopathy, the organ injuries and the lethality. Peritoneal macrophages derived from WT, Caspase-11- or GSDMD-deficient mice were stimulated with OMVs. Then the cell surface tissue factor (TF) activity and thrombin generation were assessed. RESULTS:Genetic deletion of Caspase-11 or GSDMD or pharmacological inhibition of caspase-11 markedly attenuated OMVs-induced coagulopathy, multiple organ injuries and mortality. Caspase-11- or GSDMD-deficient macrophages exhibited markedly reduced TF activity after OMVs stimulation. CONCLUSION:OMVs induce DIC through the caspase-11-GSDMD pathway. These findings might open a new avenue to prevent or treat bacterial infection-induced DIC.
10.1016/j.thromres.2020.08.013
Ampicillin triggers the release of Pal in toxic vesicles from Escherichia coli.
Michel Lea Vacca,Gallardo Leslie,Konovalova Anna,Bauer Morgan,Jackson Niaya,Zavorin Mark,McNamara Carlie,Pierce Jeanetta,Cheng Susan,Snyder Emma,Hellman Judith,Pichichero Michael E
International journal of antimicrobial agents
In addition to lipopolysaccharides (LPS), outer membrane proteins - Lpp, OmpA and peptidoglycan-associated lipoprotein (Pal) - are part of the outer membrane of Escherichia coli and are proposed to contribute to bacterial sepsis-related inflammation. This study showed that ampicillin (a β-lactam antibiotic) enhances Pal's release from Escherichia coli to a greater extent than gentamicin and levofloxacin (aminoglycoside and quinolone antibiotics, respectively). It is proposed that the majority of Pal is released in outer membrane vesicles (OMVs), which also contain LPS and other outer membrane and periplasmic proteins. The OMVs were purified by ultracentrifugation and characterised by transmission electron microscopy and nanoparticle tracking analysis, and Pal and other E. coli proteins were detected by Western blot. It also proposed that sepsis treatments using certain β-lactam antibiotics may further aggravate the over-exuberant inflammatory response by enhancing the release of Pal and LPS in OMVs.
10.1016/j.ijantimicag.2020.106163
Gene-microbiota interactions contribute to the pathogenesis of inflammatory bowel disease.
Chu Hiutung,Khosravi Arya,Kusumawardhani Indah P,Kwon Alice H K,Vasconcelos Anilton C,Cunha Larissa D,Mayer Anne E,Shen Yue,Wu Wei-Li,Kambal Amal,Targan Stephan R,Xavier Ramnik J,Ernst Peter B,Green Douglas R,McGovern Dermot P B,Virgin Herbert W,Mazmanian Sarkis K
Science (New York, N.Y.)
Inflammatory bowel disease (IBD) is associated with risk variants in the human genome and dysbiosis of the gut microbiome, though unifying principles for these findings remain largely undescribed. The human commensal Bacteroides fragilis delivers immunomodulatory molecules to immune cells via secretion of outer membrane vesicles (OMVs). We reveal that OMVs require IBD-associated genes, ATG16L1 and NOD2, to activate a noncanonical autophagy pathway during protection from colitis. ATG16L1-deficient dendritic cells do not induce regulatory T cells (T(regs)) to suppress mucosal inflammation. Immune cells from human subjects with a major risk variant in ATG16L1 are defective in T(reg) responses to OMVs. We propose that polymorphisms in susceptibility genes promote disease through defects in "sensing" protective signals from the microbiome, defining a potentially critical gene-environment etiology for IBD.
10.1126/science.aad9948
Malaria parasite DNA-harbouring vesicles activate cytosolic immune sensors.
Sisquella Xavier,Ofir-Birin Yifat,Pimentel Matthew A,Cheng Lesley,Abou Karam Paula,Sampaio Natália G,Penington Jocelyn Sietsma,Connolly Dympna,Giladi Tal,Scicluna Benjamin J,Sharples Robyn A,Waltmann Andreea,Avni Dror,Schwartz Eli,Schofield Louis,Porat Ziv,Hansen Diana S,Papenfuss Anthony T,Eriksson Emily M,Gerlic Motti,Hill Andrew F,Bowie Andrew G,Regev-Rudzki Neta
Nature communications
STING is an innate immune cytosolic adaptor for DNA sensors that engage malaria parasite (Plasmodium falciparum) or other pathogen DNA. As P. falciparum infects red blood cells and not leukocytes, how parasite DNA reaches such host cytosolic DNA sensors in immune cells is unclear. Here we show that malaria parasites inside red blood cells can engage host cytosolic innate immune cell receptors from a distance by secreting extracellular vesicles (EV) containing parasitic small RNA and genomic DNA. Upon internalization of DNA-harboring EVs by human monocytes, P. falciparum DNA is released within the host cell cytosol, leading to STING-dependent DNA sensing. STING subsequently activates the kinase TBK1, which phosphorylates the transcription factor IRF3, causing IRF3 to translocate to the nucleus and induce STING-dependent gene expression. This DNA-sensing pathway may be an important decoy mechanism to promote P. falciparum virulence and thereby may affect future strategies to treat malaria.
10.1038/s41467-017-02083-1
Dysregulated Lung Commensal Bacteria Drive Interleukin-17B Production to Promote Pulmonary Fibrosis through Their Outer Membrane Vesicles.
Yang Daping,Chen Xi,Wang Jingjing,Lou Qi,Lou Yunwei,Li Li,Wang Honglin,Chen Jiangye,Wu Meng,Song Xinyang,Qian Youcun
Immunity
Idiopathic pulmonary fibrosis (IPF) is a severe form of lung fibrosis with a high mortality rate. However, the etiology of IPF remains unknown. Here, we report that alterations in lung microbiota critically promote pulmonary fibrosis pathogenesis. We found that lung microbiota was dysregulated, and the dysregulated microbiota in turn induced production of interleukin-17B (IL-17B) during bleomycin-induced mouse lung fibrosis. Either lung-microbiota depletion or IL-17B deficiency ameliorated the disease progression. IL-17B cooperated with tumor necrosis factor-α to induce expression of neutrophil-recruiting genes and T helper 17 (Th17)-cell-promoting genes. Three pulmonary commensal microbes, which belong to the genera Bacteroides and Prevotella, were identified to promote fibrotic pathogenesis through IL-17R signaling. We further defined that the outer membrane vesicles (OMVs) that were derived from the identified commensal microbes induced IL-17B production through Toll-like receptor-Myd88 adaptor signaling. Together our data demonstrate that specific pulmonary symbiotic commensals can promote lung fibrosis by regulating a profibrotic inflammatory cytokine network.
10.1016/j.immuni.2019.02.001