Local administration of p-coumaric acid decreases lipopolysaccharide-induced acute lung injury in mice: In vitro and in silico studies.
Souza Tácio N,Santos Flávio M,Alves Polyane R,Ferro Jamylle N,Correia Ana Carolina C,Melo Tarcísio S,Soares Wagner R,Andrade Bruno S,Lagente Vincent,Barreto Emiliano
European journal of pharmacology
Acute lung injury (ALI) remains to cause a high rate of mortality in critically ill patients. It is known that inflammation is a key factor in the pathogenesis of lipopolysaccharide (LPS)-induced ALI, which makes it a relevant approach to the treatment of ALI. In this study, we evaluated the potential of nasally instilled p-coumaric acid to prevent LPS-induced ALI in mice, by evaluating its effects on cellular and molecular targets involved in inflammatory response via in vitro and in silico approaches. Our results demonstrated that p-coumaric acid reduced both neutrophil accumulation and pro-inflammatory cytokine abundance, and simultaneously increased IL-10 production at the site of inflammation, potentially contributing to protection against LPS-induced ALI in mice. In the in vitro experiments, we observed inhibitory effects of p-coumaric acid against IL-6 and IL-8 production in stimulated A549 cells, as well as reactive oxygen species generation by neutrophils. In addition, p-coumaric acid treatment decreased neutrophil adhesion on the TNF-α-stimulated endothelial cells. According to the in silico predictions, p-coumaric acid reached stable interactions with both the ATP-binding site of IKKβ as well as the regions within LFA-1, critical for interaction with ICAM-1, thereby suppressing the production of proinflammatory mediators and hindering the neutrophil infiltration, respectively. Collectively, these findings indicate that p-coumaric acid is a promising anti-inflammatory agent that can be used for developing a pharmaceutical drug for the treatment of ALI and other inflammatory disorders.
Altered lung metabolism and mitochondrial DAMPs in lung injury due to acute kidney injury.
Hepokoski Mark,Wang Jing,Li Kefeng,Li Ying,Gupta Purva,Mai Tina,Moshensky Alex,Alotaibi Mona,Crotty Alexander Laura E,Malhotra Atul,Singh Prabhleen
American journal of physiology. Lung cellular and molecular physiology
Acute respiratory distress syndrome (ARDS) is a common cause of mortality in patients with acute kidney injury (AKI). Inflammatory crosstalk from the kidney to the lung has been shown to contribute to lung injury after AKI, but anti-inflammatory therapies have not been proven beneficial in human studies. Recently, AKI was shown to alter mitochondria and related metabolic pathways in the heart, but the impact of AKI on lung metabolism has not been investigated to our knowledge. In this study, we evaluated the metabolomic profile of the lung following renal ischemia and reperfusion to identify novel pathways that may be modifiable. We randomized C57BL/6 mice to 20 minutes of bilateral renal arterial clamping or sham operation under ketamine/xylazine anesthesia. At 4 hours after reperfusion, we found a significant increase in markers of lung injury, as well as significant metabolomic changes across lung, kidney, plasma and bronchoalveolar lavage fluid (BALF) compared to shams. Comparative analyses revealed that the fatty acid oxidation pathway was the most significantly altered metabolic pathway, a finding which is consistent with mitochondrial dysfunction systemically and in the lung. These metabolomic changes correlated with the extracellular accumulation of the mitochondrial damage associated molecular patterns (mtDAMPs), mitochondrial DNA (mtDNA) and transcription factor A, mitochondria (TFAM). Finally, we found that intraperitoneal injection of renal mtDAMPs caused metabolomic changes consistent with mitochondrial dysfunction in the lung in vivo. Mitochondrial function and mtDAMPs warrant further investigation as potential therapeutic targets in preventing lung injury due to AKI.
Puerarin prevents LPS-induced acute lung injury via inhibiting inflammatory response.
Wang Xinye,Yan Jinjun,Xu Xiaohong,Duan Chunyan,Xie Zheng,Su Zheqian,Ma Hongxia,Ma Hui,Wei Xing,Du Xiaochun
Acute lung injury (ALI) is a critical illness syndrome with high morbidity and mortality in patients. Inflammation has been known to be involved in the development of ALI. The purpose of this study was to investigate the effect of puerarin on lipopolysaccharide (LPS)-induced ALI in mice. The pro-inflammatory cytokines TNF-α, IL-6 and IL-1β were determined by ELISA. Western blot analysis was used for detecting the expression of NF-κB, IκBα, and LXRα. And myeloperoxidase (MPO) activity, lung wet/dry (W/D) ratio, and histopathological examination were also detected in lung tissues. The results showed that puerarin significantly inhibited LPS-stimulated MPO activity in lung tissues. Meanwhile, puerarin attenuated lung histopathological changes and lung wet/dry (W/D) ratio. We also found that the expression of pro-inflammatory cytokines, TNF-α, IL-6 and IL-1β were inhibited by puerarin. Puerarin also inhibited LPS-induced TNF-α in RAW264.7 cells and IL-8 in A549 cells. From the results of western blotting, puerarin significantly suppressed LPS-stimulated NF-κB activation. And the expression of LXRα was dose-dependently increased by treatment of puerarin. The inhibition of puerarin on TNF-α production in RAW264.7 cells and IL-8 production in A549 cells were blocked by LXRα inhibitor geranylgeranyl pyrophosphate (GGPP). These results suggested that puerarin attenuated ALI by activating LXRα, which subsequently inhibited LPS-induced inflammatory response.
Genipin protects rats against lipopolysaccharide-induced acute lung injury by reinforcing autophagy.
Zhang Zhijie,Wang Xue,Ma Chengzhou,Li Zhiwang,Chen Huayong,Zhang Zhiming,Li Tao
Although the protective effects of genipin against acute lung injury (ALI) have been described previously, the associated mechanism remains unclear. We have previously reported that genipin exerts its pharmacological effects by regulating autophagy. Here, we hypothesized that the up-regulation of autophagy may contribute to the protective effects exhibited by genipin against ALI. In the present study, ALI was induced by intratracheal LPS administration in rats. Genipin treatment significantly reduced LPS-induced lung injury as evidenced by improved histopathology, decreased lung edema, total cells, and protein concentration in the bronchoalveolar lavage fluid (BALF). This protection was inhibited by 3-methyladenine (3-MA), an inhibitor of autophagy. Genipin treatment reduced the expression of P62 and increased the expression of Beclin-1 and LC3II, indicating increased autophagy. Genipin treatment also alleviated LPS-induced cell apoptosis (down-regulation of Bax, up-regulation of Bcl-2, and decreased number of terminal deoxynucleotidyl transferase dUTP nick end label-positive cells) and oxidative stress (increased SOD and decreased MDA content) in the lung. Furthermore, genipin attenuated LPS-induced production of TNF-α, IL-1β, and IL-6 in the lung and BALF. These protective effects induced by genipin were reversed by 3-MA treatment, indicating that autophagy was involved in the protective effects exerted by genipin against inflammation and apoptosis in ALI. In A549 cells incubated with LPS for 6 h, genipin treatment increased the number of GFP-LC3 punctae. 3-MA prevented the protective effects of genipin against mitochondrial dysfunction and cell death. These findings suggest that genipin protects against apoptosis and inflammation in LPS-induced ALI by promoting autophagy.
Propofol reduces acute lung injury by up-regulating gamma-aminobutyric acid type a receptors.
Huang Tianfeng,Zhang Yang,Wang Cunjin,Gao Ju
Experimental and molecular pathology
BACKGROUND:We used a two-hit lung injury rat model that involves mechanical ventilation (MV) following lipopolysaccharide exposure to investigate the effects of propofol on the expression of GABA receptors (GABAR) and cytokine responses, and we then determined the specific effects of GABA on cytokine responses in vitro in alveolar epithelial cells (AECs). METHODS:Forty-eight adult male Wister rats were equally and randomly divided into the following 4 groups (n = 12) using a random number table: sham group, sham+propofol group, lipopolysaccharide (LPS) + VILI group, and LPS + VILI + propofol group. All animals were anesthetized, and the animals received a 3.75 mg/kg intratracheal instillation of endotoxins or phosphate-buffered saline (PBS) as the control, as described previously. After 30 min, rats were ventilated for 5 h in a volume-controlled ventilation mode. In the LPS + VILI group, animals were ventilated with a tidal volume (Vt) of 22 ml/kg and zero positive end-expiratory pressure (PEEP) at a respiratory rate of 16-18 breaths/min, whereas control (sham) rats were ventilated with a Vt of 6 ml/kg and PEEP of 5 cmHO at a rate of 45-55 breaths/min. The FiO remained constant as 0.4, propofol was administered intravenously in the LPS + VILI + propofol and sham + propofol groups at a rate of 10 mg·kg·h while normal saline at the same rate was intravenously administered in the LPS + VILI and sham groups during the entire mechanical ventilation period. Five hours after mechanical ventilation, the rats were killed. Survival rates, histopathology, concentrations of inflammatory mediators in bronchoalveolar lavage fluid (BALF), wet weight/dry weight (W/D) ratio of the lung, myeloperoxidase (MPO) activity in lung tissues, and expression of GAD and GABAR by immunohistochemical detection and Western blotting were assessed. Then, human type II-like alveolar epithelial cells (A549 cells) were cultured to full confluence and incubated with GABA (100 nM) alone, picrotoxin alone, a GABAR antagonist (PTX, 50 nM), or GABA + PTX for 10 min, followed by stimulation with LPS (control) at 100 ng/ml for 4 h. The concentrations of IL-1β, IL-2, IL-8, and IL-10 were then measured. RESULTS:Administration of propofol in a two-hit lung injury rat model can increase survival rates and the expression of GAD and GABAR (P < .05). The administration of propofol can attenuate the release of pro-inflammatory cytokines both in vivo and in vitro, and the administration of propofol can attenuate histopathological changes, the W/D ratio, and MPO activity (P < .05). CONCLUSIONS:In this study, we found that the administration of propofol improved lung function, alleviated lung injury, and up-regulated the GAD and GABAR expressions in a two-hit model of acute lung injury (ALI) characterized by intratracheal instillation of an endotoxin and prolonged MV. Therefore, the protective effects of propofol may be associated with the up-regulation of GABA receptors in AECs.
miR-16 inhibits NLRP3 inflammasome activation by directly targeting TLR4 in acute lung injury.
Yang Yuan,Yang Feng,Yu Xinqiao,Wang Beibei,Yang Yang,Zhou Xiaoyu,Cheng Rui,Xia Shiwen,Zhou Xiaoguang
Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie
Acute lung injury (ALI) is the leading cause of human death, and it is widely accepted that the runaway inflammation is an important risk for the development of ALI. In the present study, we aimed to investigate the effect of miR-16 on lipopolysaccharide-induced acute lung injury in mice, especially focusing on Toll-like receptor 4 (TLR4) and NF-kB signaling pathway as well as NOD-like receptor protein 3 (NLRP3) inflammasome activation. We established in vivo and in vitro model of ALI using LPS and demonstrated that miR-16 expression was down-regulated in lung tissue as well as A549 cells after 8 h of LPS treatment. Furthermore, when miR-16 levels in lung tissues were up-regulated by miR-16 agomir, it was confirmed that the mRNA and protein levels of NF-κB, NLRP3 inflammasome, and inflammatory factors were decreased by the miR-16 by directly targeting TLR4. We also treated A549 cells with miR-16 mimics and anti-miR-16 to confirm the results. Overall, our experiments showed that miR-16 protects against acute lung injury in mice by regulating the TLR4/ NF-κB pathway and attenuating inflammatory response. This work suggests a potential novel therapeutic approach to combat ALI.
Inhibition of tyrosine kinases protects against lipopolysaccharide-induced acute lung injury by preventing nuclear export of Nrf2.
Duan Jiaxiang,Yang Zhen,Huang Jian,Zhu Yuan,Zhao Hailin,Unwith Sandeep,Gao Xian,Lu Kaizhi,Ning Jiaolin
Journal of cellular biochemistry
Acute Lung Injury is a common severe pathological condition that is usually caused by lipopolysaccharide (LPS) infection from bacteria. Enhanced activity of nuclear factor erythroid 2-related factor 2 (Nrf2) could attenuate LPS induced lung injury, However, it still remains unknown whether the enhanced activity of Nrf2 via suppression of Nrf2 nucleus export attenuates the LPS induced lung injury. The aim of this study is to investigate the effects of inhibitors of Fyn on the LPS-induced acute lung injury and to explore its underlying molecular mechanisms. Nrf2 localization in the cells was observed by using confocal microscopy and its transcriptional activation was measured by Electrophoretic Mobility Shift Assay and controlled genes expression levels. The lung injury severity was examined by histopathological scoring and oxidative stress level. In this study, we showed that PP2, LMB, and Nrf2 Y568A abrogated Nrf2 nuclear export and thus enhance the Nrf2 transcriptional activity. PP2 attenuated lung injury and the reduction of cells viability induced by LPS. The current study demonstrated, for the first time, that increase of expression of Nrf2 controlled protective genes via suppression of Nrf2 nucleus export could attenuate lung injury.
Irisin alleviates pulmonary epithelial barrier dysfunction in sepsis-induced acute lung injury via activation of AMPK/SIRT1 pathways.
Li Xinyi,Jamal Muhammad,Guo Peipei,Jin Zhao,Zheng Feng,Song Xuemin,Zhan Jia,Wu Huisheng
Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie
OBJECTIVE:Alveolar epithelial barrier dysfunction in response to inflammatory reaction contributes to pulmonary edema in acute lung injury(ALI).Irisin,a newly-found myokine,exerts the anti-inflammatory effects. This study aims to investigate the protective effects of irisin on lipopolysaccharide (LPS)-induced ALIin vivo and in vitro, and to explore its underlying mechanism. METHODS:Male SD rats and A549 cells were divided into 4 groups: control group, LPS group, Irisin pretreated group, and Irisin/Compound C(a special inhibitor of AMPK)-treated group. The ALI model was established by intravenous injection of LPS in rats, and LPS challenge in A549 cells. Pulmonary specimens were harvested for microscopic examination of the pathological changes, and the expression of AMPK,SIRT1,NF-κB, p66Shc and caspase-3 in lung tissues. The pulmonary permeability were examined by wet/dry lung weight ratio(W/D) and lung permeability index(LPI). The apoptotic index, and the expression of tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), monocyte chemoattractant activating protein-1 (MCP-1), tight junctions (occludin,ZO-1) were determined both in lung tissue and A549 cells. RESULTS:Irisin alleviated lung histological changes and decreased pulmonary microvascular permeability in LPS-induced rats. Irisin up-regulated the expression of occludin, ZO-1,AMPK,SIRT1, down-regulated the expression of TNF-α,IL-1β,MCP-1,NF-κB, p66Shc caspase-3, and decreased the apoptotic index in LPS-induced rats and A549 cells. All these protective effects of irisin could be reversed by Compound C. CONCLUSION:Irisin improved LPS-induced alveolar epithelial barrier dysfunction via suppressing inflammation and apoptosis, and this protective effect might be mediated by activating AMPK/SIRT1 pathways.
Serum‑free‑medium‑type mesenchymal stem cell culture supernatant exerts a protective effect on A549 lung epithelial cells in acute lung injury induced by H2O2.
Wu Jian,Shang An-Quan,Chen Chu,Wang Wei-Wei,Xiong Cun-Quan,Guo Nai-Zhou
The aim of the present study was to investigate the mechanisms and protective effect of serum‑free‑medium‑type fetal placental mesenchymal stem cell (fPMSC) culture supernatant on A549 lung epithelial cells following treatment with hydrogen peroxide (H2O2). A549 lung epithelial cells were stimulated with different concentrations of H2O2, and the survival rate of the cells was examined by Cell Counting Kit‑8 (CCK‑8) assay. It was concluded that the H2O2 concentration when the cell survival rate was at 50% was the optimum condition to create an oxidative damage model. Hoechst 33258 staining and western blot analysis was used to validate the A549 lung epithelial cell model. Serum‑free medium was used to culture fPMSCs, and A549 lung epithelial cells treated with H2O2 were cultured with passage 3 MSC supernatant for 24 h. This was termed the supernatant group. Simultaneously, a damage group that was stimulated with H2O2 only, and a vitamin C (VC) group that was treated with H2O2 followed by 100 µmol/l VC in culture medium was also established. The apoptosis of the three groups was detected by flow cytometry, and western blotting was used to detect apoptosis‑associated and nuclear factor erythroid 2‑like 2 (Nrf2)‑kelch‑like ECH‑associated protein 1 (Keap1)‑antioxidant response element/oxidative stress‑associated protein expression. Following the CCK‑8 test, 600 µmol/l H2O2 was selected to stimulate the A549 lung epithelial cells for 24 h, which resulted in a A549 cell survival rate of 56.41±3.31%. Hoechst 33258 staining and western blotting also confirmed the reliability of the model. Flow cytometry demonstrated that the apoptotic rate of the cells in the VC and supernatant groups was reduced compared with that in the injury group. The difference between the supernatant group and the injury group was statistically significant. The detection of apoptosis‑associated proteins by western blotting revealed that the expression of apoptosis regulator BAX and Caspase‑3 in the VC and supernatant groups was decreased. Furthermore, the expression of B‑cell lymphoma‑2 was increased compared with that in the injury group, and the difference was statistically significant (P<0.05). Compared with that in the injury group, the expression of Nrf2 increased in the VC and supernatant groups, whereas the expression of Keap1 was decreased, and the difference was statistically significant (P<0.05). In conclusion, fPMSC supernatant exhibited an antioxidant capacity in A549 lung epithelial cells treated with H2O2 as a model of acute lung injury. The supernatant was found to reduce oxidative damage and inhibit apoptosis.
Mesenchymal stem cells alleviate LPS-induced acute lung injury by inhibiting the proinflammatory function of Ly6C CD8 T cells.
Zhu Jiaqi,Feng Bing,Xu Yanping,Chen Wenyi,Sheng Xinyu,Feng Xudong,Shi Xiaowei,Liu Jingqi,Pan Qiaoling,Yu Jiong,Li Lanjuan,Cao Hongcui
Cell death & disease
Systemic inflammatory processes, including alveolar injury, cytokine induction, and neutrophil accumulation, play key roles in the pathophysiology of acute lung injury (ALI). The immunomodulatory effects of mesenchymal stem cells (MSCs) can contribute to the treatment of inflammatory disorders. In previous studies, the focus was on innate immune cells and the effects of MSCs on ALI through CD8 T cells remain unclear. In the present study, lipopolysaccharide (LPS) was used to induce ALI in mice. ALI mice were treated with MSCs via intratracheal instillation. Survival rate, histopathological changes, protein levels, total cell count, cytokine levels, and chemokine levels in alveolar lavage fluid were used to determine the efficacy of MSCs. Mass cytometry and single-cell RNA sequencing (scRNA-seq) were used to characterize the CD8 T cells in the lungs. Ly6C CD8 T cells are prevalent in normal mice, whereas a specialized effector phenotype expressing a high level of Ly6C is predominant in advanced disease. MSCs significantly mitigated ALI and improved survival. MSCs decreased the infiltration of CD8 T cells, especially Ly6C CD8 T cells into the lungs. Mass cytometry revealed that CD8 T cells expressing high Ly6C and CXCR3 levels caused tissue damage in the lungs of ALI mice, which was alleviated by MSCs. The scRNA-seq showed that Ly6C CD8 T cells exhibited a more activated phenotype and decreased expression of proinflammatory factors that were enriched the most in immune chemotaxis after treatment with MSCs. We showed that CD8 T cells play an important role in MSC-mediated ALI remission, and both infiltration quantity and proinflammatory function were inhibited by MSCs, indicating a potential mechanism for therapeutic intervention.
Mesenchymal stem cells reverse EMT process through blocking the activation of NF-κB and Hedgehog pathways in LPS-induced acute lung injury.
Xiao Kun,He Wanxue,Guan Wei,Hou Fei,Yan Peng,Xu Jianqiao,Zhou Ting,Liu Yuhong,Xie Lixin
Cell death & disease
Acute lung injury (ALI) is a pulmonary disorder, which can result in fibrosis of the lung tissues. Recently, mesenchymal stem cell (MSC) has become a novel therapeutic method for ALI. However, the potential mechanism by which MSC regulates the progression of ALI remains blurry. The present study focused on investigating the mechanism underneath MSC-reversed lung injury and fibrosis. At first, we determined that coculture with MSC led to the inactivation of NF-κB signaling and therefore suppressed hedgehog pathway in LPS-treated MLE-12 cells. Besides, we confirmed that MSC-exosomes were responsible for the inhibition of EMT process in LPS-treated MLE-12 cells through transmitting miRNAs. Mechanism investigation revealed that MSC-exosome transmitted miR-182-5p and miR-23a-3p into LPS-treated MLE-12 cells to, respectively, target Ikbkb and Usp5. Of note, Usp5 interacted with IKKβ to hamper IKKβ ubiquitination. Moreover, co-inhibition of miR-182-5p and miR-23a-3p offset the suppression of MSC on EMT process in LPS-treated MLE-12 cells as well as in LPS-injured lungs of mice. Besides, the retarding effect of MSC on p65 nuclear translocation was also counteracted after co-inhibiting miR-182-5p and miR-23a-3p, both in vitro and in vivo. In summary, MSC-exosome transmitted miR-23a-3p and miR-182-5p reversed the progression of LPS-induced lung injury and fibrosis through inhibiting NF-κB and hedgehog pathways via silencing Ikbkb and destabilizing IKKβ.
Lian Hua Qing Wen Capsules, a Potent Epithelial Protector in Acute Lung Injury Model, Block Proapoptotic Communication Between Macrophages, and Alveolar Epithelial Cells.
Li Qi,Ran Qingsen,Sun Lidong,Yin Jie,Luo Ting,Liu Li,Zhao Zheng,Yang Qing,Li Yujie,Chen Ying,Weng Xiaogang,Wang Yajie,Cai Weiyan,Zhu Xiaoxin
Frontiers in pharmacology
Besides pathogen evading, Acute Lung Injury (ALI), featuring the systematic inflammation and severe epithelial damages, is widely believed to be the central non-infectious factor controlling the progression of infectious diseases. ALI is partly caused by host immune responses. Under the inspiration of unsuccessful treatment in COVID-19, recent insights into pathogen-host interactions are leading to identification and development of a wide range of host-directed therapies with different mechanisms of action. The interaction unit consisting of macrophages and the alveolar epithelial cells has recently revealed as the therapeutic basis targeting ALI. Lian Hua Qing Wen capsule is the most effective and commonly-used clinical formula in treating respiratory infection for thousands of years in China. However, little is known about its relevance with ALI, especially its protective role against ALI-induced alveolar tissue damages. Aiming to evaluate its contribution in antibiotics-integrating therapies, this study pharmacologically verified whether LHQW could alleviate lipopolysaccharide (LPS)-induced ALI and explore its potential mechanisms in maintaining the physiology of macrophage-epithelial unit. In ALI mouse model, the pathological parameters, including the anal temperature, inflammation condition, lung edema, histopathological structures, have all been systematically analyzed. Results consistently supported the effectiveness of the combined strategy for LHQW and low-dose antibiotics. Furthermore, we established the macrophages-alveolar epithelial cells co-culture model and firstly proved that LHQW inhibited LPS-induced ER stress and TRAIL secretion in macrophages, thereby efficiently protected epithelial cells against TRAIL-induced apoptosis. Mechanistically, results showed that LHQW significantly deactivated NF-κB and reversed the SOCS3 expression in inflammatory macrophages. Furthermore, we proved that the therapeutic effects of LHQW were highly dependent on JNK-AP1 regulation. In conclusion, our data proved that LHQW is an epithelial protector in ALI, implying its promising potential in antibiotic alternative therapy.
A Peptidyl Inhibitor that Blocks Calcineurin-NFAT Interaction and Prevents Acute Lung Injury.
Dougherty Patrick G,Karpurapu Manjula,Koley Amritendu,Lukowski Jessica K,Qian Ziqing,Srinivas Nirujogi Teja,Rusu Luiza,Chung Sangwoon,Hummon Amanda B,Li Hao W,Christman John W,Pei Dehua
Journal of medicinal chemistry
Acute respiratory distress syndrome (ARDS) is an inflammatory lung disease with a high morbidity and mortality rate, for which no pharmacologic treatment is currently available. Our previous studies discovered that a pivotal step in the disease process is the activation of the nuclear factor of activated T cells (NFAT) c3 in lung macrophages, suggesting that inhibitors against the upstream protein phosphatase calcineurin should be effective for prevention/treatment of ARDS. Herein, we report the development of a highly potent, cell-permeable, and metabolically stable peptidyl inhibitor, CNI103, which selectively blocks the interaction between calcineurin and NFATc3, through computational and medicinal chemistry. CNI103 specifically inhibited calcineurin signaling and and exhibited a favorable pharmacokinetic profile, broad tissue distribution following different routes of administration, and minimal toxicity. Our data indicate that CNI103 is a promising novel treatment for ARDS and other inflammatory diseases.
MicroRNA-31-5p Exacerbates Lipopolysaccharide-Induced Acute Lung Injury via Inactivating Cab39/AMPK Pathway.
Jiang Wan-Li,Zhao Kao-Chang,Yuan Wen,Zhou Fang,Song Heng-Ya,Liu Gao-Li,Huang Jie,Zou Jin-Jing,Zhao Bo,Xie Song-Ping
Oxidative medicine and cellular longevity
Acute lung injury (ALI) and the subsequent acute respiratory distress syndrome remain devastating diseases with high mortality rates and poor prognoses among patients in intensive care units. The present study is aimed at investigating the role and underlying mechanisms of microRNA-31-5p () on lipopolysaccharide- (LPS-) induced ALI. Mice were pretreated with agomir, antagomir, and their negative controls at indicated doses for 3 consecutive days, and then they received a single intratracheal injection of LPS (5 mg/kg) for 12 h to induce ALI. MH-S murine alveolar macrophage cell lines were cultured to further verify the role of in vitro. For AMP-activated protein kinase (AMPK) and calcium-binding protein 39 (Cab39) inhibition, compound C or lentiviral vectors were used in vivo and in vitro. We observed an upregulation of in lung tissue upon LPS injection. antagomir alleviated, while agomir exacerbated LPS-induced inflammation, oxidative damage, and pulmonary dysfunction in vivo and in vitro. Mechanistically, antagomir activated AMPK to exert the protective effects that were abrogated by AMPK inhibition. Further studies revealed that Cab39 was required for AMPK activation and pulmonary protection by antagomir. We provide the evidence that endogenous is a key pathogenic factor for inflammation and oxidative damage during LPS-induced ALI, which is related to Cab39-dependent inhibition of AMPK.
Negative Effects of SIGIRR on TRAF6 Ubiquitination in Acute Lung Injury In Vitro.
Tian Feng,Lu Qiang,Lei Jie,Ni Yunfeng,Xie Nianlin,Zhong Daixing,Yang Guang,Si Shaokui,Jiang Tao
Journal of immunology research
In this study, the effects of single immunoglobin IL-1 receptor-related protein (SIGIRR) on tumor necrosis factor- (TNF-) receptor-associated factor 6 (TRAF6) ubiquitination in acute lung injury (ALI) were evaluated in both alveolar epithelial cells and alveolar macrophage cells in vitro. Our results found that SIGIRR negatively regulated TRAF6 ubiquitination and such SIGIRR inhibition could enhance the TRAF6 expression in both alveolar epithelial cells (AECs) and alveolar macrophage cells (AMCs). SIGIRR knockdown may increase NF-B activity via TRAF6 regulation by the classical but not the nonclassical NF-B signaling pathway. Such modulation between TRAF6 and SIGIRR could affect cytokine secretion and exacerbate the immune response; the IL-8, NFKB1, and NFKBIA mRNA levels were reduced after SIGIRR overexpression. The current study reveals the molecular mechanisms of the negative regulatory roles of SIGIRR on the innate immune response related to the LPS/TLR-4 signaling pathway and provides evidence for strategies to clinically treat inflammatory diseases.
LPS-induced vein endothelial cell injury and acute lung injury have Btk and Orai 1 to regulate SOC-mediated calcium influx.
Qiu Xiaochen,Liang Xiaobo,Li Hengyu,Sun Rongju
Patients with sepsis and sepsis-related complications have a high mortality. Endothelial cell dysfunction plays a central role in sepsis pathophysiological process. In sepsis patients, endothelial cell apoptosis is associated with intracellular calcium overload. Multiple functions in the apoptotic process have been found to be regulated by calcium signaling. Our previous work had proved that LPS-induced cell injury was associated with store-operated calcium (SOC) entry mediated by stromal interaction molecule-1 (STIM 1) in Human umbilical vein endothelial cells (HUVEC), but the underlying molecular mechanism has not been adequately defined. Here we report that the LPS-induced cell injury is related to the calcium overload in HUVEC. SOC entry mediated by calcium release-activated calcium modulator (Orai) 1 and transient receptor potential canonical (TRPC) 1 was associated with LPS-induced calcium overload and cell apoptosis. Bruton's tyrosine kinase (Btk)/Phospholipase C(PLC) γ/inositol 1,4,5-triphosphate receptor (IPR) played a major role in regulating calcium overload in LPS-induced HUVEC. Knockdown of Btk markedly inhibited the expressions of Orai 1 and its downstream molecule IPR but not that of TRPC1 in LPS-induced HUVEC. In mice, knockdown of Btk and Orai 1 inhibited LPS-induced calcium overload, pulmonary vascular endothelial cell (VEC) injury and acute lung injury. These findings demonstrated that Btk acts as a regulator of calcium-dependent signaling, especially in the Orai 1-mediated SOC entry of the LPS-induced VEC.
Mitochondrial Damage-Associated Molecular Patterns Exacerbate Lung Fluid Imbalance Via the Formyl Peptide Receptor-1 Signaling Pathway in Acute Lung Injury.
Yuan Zhi-Cheng,Zeng Ni,Liu Lian,Wang Tao,Dai Lu-Qi,Wang Hao,Zeng Zi-Jian,Cao Yu-Fang,Zhou Yong-Fang,Xu Dan,Shen Yong-Chun,Wen Fu-Qiang
Critical care medicine
OBJECTIVES:To investigate the effect of mitochondrial damage-associated molecular patterns on the lung fluid homeostasis in experimental acute lung injury. DESIGN:Experimental study. SETTING:Research laboratory. SUBJECTS:Patients with acute respiratory distress syndrome and control subjects, wild-type C57BL/6 and formyl peptide receptor-1 gene knockout mice, and primary rat alveolar epithelial type II cells. INTERVENTIONS:Samples of bronchoalveolar lavage fluid and serum were obtained from patients and control subjects. Mice were intratracheally instilled with lipopolysaccharide and mitochondrial damage-associated molecular patterns. The primary rat alveolar epithelial type II cells were isolated and incubated with mitochondrial damage-associated molecular patterns. MEASUREMENTS AND MAIN RESULTS:Patients were divided into direct (pulmonary) and indirect (extrapulmonary) injury groups based on etiology. The release of mitochondrial peptide nicotinamide adenine dinucleotide dehydrogenase 1 in both bronchoalveolar lavage fluid and serum was induced in patients and was associated with etiology. In the lipopolysaccharide-induced lung injury, administration of mitochondrial damage-associated molecular patterns exacerbated the lung fluid imbalance, which was mitigated in formyl peptide receptor-1 knockout mice. Proteomic analysis of mouse lung tissues revealed the involvement of ion channels and tight junction proteins in this process. Treatment with mitochondrial damage-associated molecular patterns decreased the expression of epithelial sodium channel α, zonula occludens-1, and occludin via the formyl peptide receptor-1/p38 pathway in the primary rat alveolar epithelial type II cells. CONCLUSIONS:Mitochondrial damage-associated molecular patterns exacerbate lung fluid imbalance in the experimental acute lung injury model through formyl peptide receptor-1 signaling, the inhibition of which may prevent exacerbation of lung fluid imbalance induced by mitochondrial damage-associated molecular patterns. Thus, formyl peptide receptor-1 is a potential therapeutic target for acute respiratory distress syndrome.
[Research progress on polarization regulation mechanism of alveolar macrophages in acute lung injury].
Wang Sheng,Zheng Li,Lyu Xin
Zhonghua wei zhong bing ji jiu yi xue
Acute lung injury (ALI) is a common clinical critical disease, with a high mortality. The imbalance of alveolar macrophage (AMs) polarization plays an important role in the occurrence and development of ALI inflammation. The study of the regulation mode and mechanism of macrophage polarization can provide more theoretical basis for clinical prevention and treatment of ALI. In recent years, it has been found that epigenetics and immune metabolic microenvironment can affect the macrophage polarization and the immune inflammatory response of ALI. In this review, the progress of macrophage polarization, epigenetics and immune metabolism regulating macrophage polarization, the relationship between macrophage polarization and ALI were summarized, so as to clarify the effect and significance of regulating macrophage polarization on ALI, and provide new ideas for the prevention and treatment of ALI in clinic.
Protective function of DJ-1/PARK7 in lipopolysaccharide and ventilator-induced acute lung injury.
Amatullah Hajera,Maron-Gutierrez Tatiana,Shan Yuexin,Gupta Sahil,Tsoporis James N,Varkouhi Amir K,Teixeira Monteiro Ana Paula,He Xiaolin,Yin Jun,Marshall John C,Rocco Patricia R M,Zhang Haibo,Kuebler Wolfgang M,Dos Santos Claudia C
Oxidative stress is considered one of the early underlying contributors of acute lung injury (ALI) and ventilator-induced lung injury (VILI). DJ-1, also known as PARK7, has a well-established role as an antioxidant. We have previously shown maintaining oxidative balance via the ATF3-Nrf2 axis was important in protection from ALI. Here, we exclusively characterize the role of DJ-1 in sterile LPS-induced ALI and VILI. DJ-1 protein expression was increased after LPS treatment in human epithelial and endothelial cell lines and lungs of wild-type mice. DJ-1 deficient mice exhibited greater susceptibility to LPS-induced acute lung injury as demonstrated by increased cellular infiltration, augmented levels of pulmonary cytokines, enhanced ROS levels and oxidized by-products, increased pulmonary edema and cell death. In a two-hit model of LPS and mechanical ventilation (MV), DJ-1 deficient mice displayed enhanced susceptibility to inflammation and lung injury. Collectively, these results identify DJ-1 as a negative regulator of ROS and inflammation, and suggest its expression protects from sterile lung injury driven by high oxidative stress.
RAC1 nitration at Y IS involved in the endothelial barrier disruption associated with lipopolysaccharide-mediated acute lung injury.
Wang Ting,Yegambaram Manivannan,Gross Christine,Sun Xutong,Lu Qing,Wang Hui,Wu Xiaomin,Kangath Archana,Tang Haiyang,Aggarwal Saurabh,Black Stephen M
Acute lung injury (ALI), a devastating illness induced by systemic inflammation e.g., sepsis or local lung inflammation e.g., COVID-19 mediated severe pneumonia, has an unacceptably high mortality and has no effective therapy. ALI is associated with increased pulmonary microvascular hyperpermeability and alveolar flooding. The small Rho GTPases, RhoA and Rac1 are central regulators of vascular permeability through cytoskeleton rearrangements. RhoA and Rac1 have opposing functional outcome: RhoA induces an endothelial contractile phenotype and barrier disruption, while Rac1 stabilizes endothelial junctions and increases barrier integrity. In ALI, RhoA activity is increased while Rac1 activity is reduced. We have shown that the activation of RhoA in lipopolysaccharide (LPS)-mediated ALI, is dependent, at least in part, on a single nitration event at tyrosine (Y). Thus, the purpose of this study was to determine if the inhibition of Rac1 is also dependent on its nitration. Our data show that Rac1 inhibition by LPS is associated with its nitration that mass spectrometry identified as Y, within the switch I region adjacent to the nucleotide-binding site. Using a molecular modeling approach, we designed a nitration shielding peptide for Rac1, designated NipR2 (nitration inhibitor peptide for the Rho GTPases 2), which attenuated the LPS-induced nitration of Rac1 at Y, preserves Rac1 activity and attenuates the LPS-mediated disruption of the endothelial barrier in human lung microvascular endothelial cells (HLMVEC). Using a murine model of ALI induced by intratracheal installation of LPS we found that NipR2 successfully prevented Rac1 nitration and Rac1 inhibition, and more importantly attenuated pulmonary inflammation, reduced lung injury and prevented the loss of lung function. Together, our data identify a new post-translational mechanism of Rac1 inhibition through its nitration at Y. As NipR2 also reduces sepsis induced ALI in the mouse lung, we conclude that Rac1 nitration is a therapeutic target in ALI.
Cellular and molecular features of senescence in acute lung injury.
Huidobro Covadonga,Martín-Vicente Paula,López-Martínez Cecilia,Alonso-López Inés,Amado-Rodríguez Laura,Crespo Irene,M Albaiceta Guillermo
Mechanisms of ageing and development
A wide range of insults can trigger acute injury in the lungs, which eventually may lead to respiratory failure and death of patients. Current treatment relies mainly on supportive measures and mechanical ventilation. Even so, survivors frequently develop important sequels that compromise quality of life. In the search for new approaches to prevent and treat acute lung injury, many investigations have focused on molecular and cellular pathways which could exert a pathogenic role in this disease. Herein, we review recent findings in the literature suggesting that cellular senescence could be involved in lung injury and discuss the potential use of senotherapies to prevent disease progression.
Hypoxia-Inducible Factor-1: A Potential Target to Treat Acute Lung Injury.
Liu Yang,Xiang Du,Zhang Hengcheng,Yao Hanlin,Wang Yanfeng
Oxidative medicine and cellular longevity
Acute lung injury (ALI) is an acute hypoxic respiratory insufficiency caused by various intra- and extrapulmonary injury factors. Presently, excessive inflammation in the lung and the apoptosis of alveolar epithelial cells are considered to be the key factors in the pathogenesis of ALI. Hypoxia-inducible factor-1 (HIF-1) is an oxygen-dependent conversion activator that is closely related to the activity of reactive oxygen species (ROS). HIF-1 has been shown to play an important role in ALI and can be used as a potential therapeutic target for ALI. This manuscript will introduce the progress of HIF-1 in ALI and explore the feasibility of applying inhibitors of HIF-1 to ALI, which brings hope for the treatment of ALI.
Inflammasome activation in acute lung injury.
McVey Mark J,Steinberg Benjamin E,Goldenberg Neil M
American journal of physiology. Lung cellular and molecular physiology
Inflammasomes are multiprotein complexes tasked with sensing endogenous or exogenous inflammatory signals and integrating this signal into a downstream response. Inflammasome activation has been implicated in a variety of pulmonary diseases, including pulmonary hypertension, bacterial pneumonia, COPD, and asthma. Of increasing interest is the contribution of inflammasome activation in the context of acute lung injury/acute respiratory distress syndrome (ALI/ARDS). Inflammasome activation in both the lung parenchyma and resident immune cells generates intereukin-1β (IL-1β) and IL-18, both of which drive the cascade of lung inflammation forward. Blockade of these responses has been shown to be beneficial in animal models and is a focus of translational research in the field. In this review, we will discuss the assembly and regulation of inflammasomes during lung inflammation, highlighting therapeutically viable effector steps. We will examine the importance of IL-1β and IL-18, two key products of inflammasome activation, in ALI, as well as the contribution of the pulmonary endothelial cell to this process. Finally, we will explore translational research moving toward anti-inflammasome therapies for ALI/ARDS and speculate toward future directions for the field.
Fucoxanthin attenuates LPS-induced acute lung injury via inhibition of the TLR4/MyD88 signaling axis.
Li Xiaoling,Huang Riming,Liu Kaifeng,Li Mingyue,Luo Hui,Cui Liao,Huang Lei,Luo Lianxiang
Acute lung injury (ALI) is a critical clinical condition with a high mortality rate. It is believed that the inflammatory storm is a critical contributor to the occurrence of ALI. Fucoxanthin is a natural extract from marine seaweed with remarkable biological properties, including antioxidant, anti-tumor, and anti-obesity. However, the anti-inflammatory activity of Fucoxanthin has not been extensively studied. The current study aimed to elucidate the effects and the molecular mechanism of Fucoxanthin on lipopolysaccharide-induced acute lung injury. In this study, Fucoxanthin efficiently reduced the mRNA expression of pro-inflammatory factors, including IL-10, IL-6, iNOS, and Cox-2, and down-regulated the NF-κB signaling pathway in Raw264.7 macrophages. Furthermore, based on the network pharmacological analysis, our results showed that anti-inflammation signaling pathways were screened as fundamental action mechanisms of Fucoxanthin on ALI. Fucoxanthin also significantly ameliorated the inflammatory responses in LPS-induced ALI mice. Interestingly, our results revealed that Fucoxanthin prevented the expression of TLR4/MyD88 in Raw264.7 macrophages. We further validated Fucoxanthin binds to the TLR4 pocket using molecular docking simulations. Altogether, these results suggest that Fucoxanthin suppresses the TLR4/MyD88 signaling axis by targeting TLR4, which inhibits LPS-induced ALI, and fucoxanthin inhibition may provide a novel strategy for controlling the initiation and progression of ALI.
Comparison of direct and indirect models of early induced acute lung injury.
Chimenti Laura,Morales-Quinteros Luis,Puig Ferranda,Camprubi-Rimblas Marta,Guillamat-Prats Raquel,Gómez Maria Nieves,Tijero Jessica,Blanch Lluis,Matute-Bello Gustavo,Artigas Antonio
Intensive care medicine experimental
BACKGROUND:The animal experimental counterpart of human acute respiratory distress syndrome (ARDS) is acute lung injury (ALI). Most models of ALI involve reproducing the clinical risk factors associated with human ARDS, such as sepsis or acid aspiration; however, none of these models fully replicates human ARDS. AIM:To compare different experimental animal models of ALI, based on direct or indirect mechanisms of lung injury, to characterize a model which more closely could reproduce the acute phase of human ARDS. MATERIALS AND METHODS:Adult male Sprague-Dawley rats were subjected to intratracheal instillations of (1) HCl to mimic aspiration of gastric contents; (2) lipopolysaccharide (LPS) to mimic bacterial infection; (3) HCl followed by LPS to mimic aspiration of gastric contents with bacterial superinfection; or (4) cecal ligation and puncture (CLP) to induce peritonitis and mimic sepsis. Rats were sacrificed 24 h after instillations or 24 h after CLP. RESULTS:At 24 h, rats instilled with LPS or HCl-LPS had increased lung permeability, alveolar neutrophilic recruitment and inflammatory markers (GRO/KC, TNF-α, MCP-1, IL-1β, IL-6). Rats receiving only HCl or subjected to CLP had no evidence of lung injury. CONCLUSIONS:Rat models of ALI induced directly by LPS or HCl-LPS more closely reproduced the acute phase of human ARDS than the CLP model of indirectly induced ALI.
Down-regulation of miR-let-7e attenuates LPS-induced acute lung injury in mice via inhibiting pulmonary inflammation by targeting SCOS1/NF-κB pathway.
Li Wuquan,Zhang Wentao,Liu Jun,Han Yalong,Jiang He,Ji Gang,Liu Wenjun
Excessive pulmonary inflammatory response is critical in the development of acute lung injury (ALI). Previously, microRNAs (miRNAs) have been recognized as an important regulator of inflammation in various diseases. However, the effects and mechanisms of miRNAs on inflammatory response in ALI remain unclear. Herein, we tried to screen miRNAs in the processes of ALI and elucidate the potential mechanism. Using a microarray assay, microRNA let-7e (let-7e) was chose as our target for its reported suppressive roles in several inflammatory diseases. Down-regulation of let-7e by antagomiR-let-7e injection attenuated LPS-induced acute lung injury. We also found that antagomiR-let-7e could obviously improve the survival rate in ALI mice. Moreover, antagomiR-let-7e treatment reduced the production of proinflammatory cytokines (i.e., TNF-α, IL-1β and IL-6) in bronchoalveolar lavage fluid (BALF) of LPS-induced ALI mice. Luciferase reporter assays confirmed that suppressor of cytokine signaling 1 (SOCS1), a powerful attenuator of nuclear factor kappa B (NF-κB) signaling pathway, was directly targeted and suppressed by let-7e in RAW264.7 cells. In addition, it was further observed that SOCS1 was down-regulated, and inversely correlated with let-7e expression levels in lung tissues of ALI mice. Finally, down-regulation of let-7e suppressed the activation of NF-κB pathway, as evidenced by the reduction of p-IκBα, and nuclear p-p65 expressions in ALI mice. Collectively, our findings indicate that let-7e antagomir protects mice against LPS-induced lung injury via repressing the pulmonary inflammation though regulation of SOCS1/NF-κB pathway, and let-7e may act as a potential therapeutic target for ALI.
Acute lung injury - from pathophysiology to treatment.
Acute lung injury is characterized by acute respiratory insufficiency with tachypnea, cyanosis refractory to oxygen, decreased lung compliance, and diffuse alveolar infiltrates on chest X-ray. The 1994 American-European Consensus Conference defined "acute respiratory distress syndrome, ARDS" by acute onset after a known trigger, severe hypoxemia defined by PaO2/FiO2</=200 mm Hg, bilateral infiltrates on chest X-ray, and absence of cardiogenic edema. Milder form of the syndrome with PaO2/FiO2 between 200-300 mm Hg was named "acute lung injury, ALI". Berlin Classification in 2012 defined three categories of ARDS according to hypoxemia (mild, moderate, and severe), and the term "acute lung injury" was assigned for general description or for animal models. ALI/ARDS can originate from direct lung triggers such as pneumonia or aspiration, or from extrapulmonary reasons such as sepsis or trauma. Despite growing understanding the ARDS pathophysiology, efficacy of standard treatments, such as lung protective ventilation, prone positioning, and neuromuscular blockers, is often limited. However, there is an increasing evidence that direct and indirect forms of ARDS may differ not only in the manifestations of alterations, but also in the response to treatment. Thus, individualized treatment according to ARDS subtypes may enhance the efficacy of given treatment and improve the survival of patients.
CD39 Regulatory T Cells Attenuate Lipopolysaccharide-Induced Acute Lung Injury Autophagy and the ERK/FOS Pathway.
Chen Cen,Li Xinying,Li Chuling,Jin Jiajia,Wang Donghui,Zhao Yuan,Gu Yanli,Chen Meizi,Zhu Suhua,Liu Hongbing,Lv Tangfeng,Zhang Fang,Song Yong
Frontiers in immunology
Acute respiratory distress syndrome (ARDS) is characterized by an uncontrollable cytokine storm, which is associated with high mortality due to lack of effective treatment. Regulatory T cells (Tregs) play an indispensable role in maintaining immune homeostasis and CD39 is considered as a functional cell marker of Tregs. In this study, we aimed to evaluate the effect of CD39 Tregs on acute lung injury (ALI) and investigate the frequency of CD39 Tregs in ARDS patients. We found that after lipopolysaccharide (LPS) treatment, CD39 mice exhibited more severe inflammation and wild type (WT) mice exhibited a decreased frequency of CD39 Tregs in the peripheral blood. Furthermore, CD39 Tregs had a protective effect on LPS-induced inflammation and the adoptive transfer of CD39 Tregs had a therapeutic effect on ALI . We further sought to explore the mechanisms that affect CD39 expression on Tregs. LPS-induced inflammation in the lung impaired the immunosuppressive effect of Tregs the autophagy-mediated downregulation of CD39. In addition, CD39 induced the expression of itself in Tregs activating the ERK1/2-FOS pathway. Consistent with this finding, the frequency of CD39 Tregs was also decreased in the peripheral blood of ARDS patients and was positively correlated with disease severity. Our results suggested that the adoptive transfer of CD39 Tregs may provide a novel method for the clinical prevention and treatment of ARDS.
Heme oxygenase-1(HO-1) regulates Golgi stress and attenuates endotoxin-induced acute lung injury through hypoxia inducible factor-1α (HIF-1α)/HO-1 signaling pathway.
Li Xiangyun,Yu Jianbo,Gong Lirong,Zhang Yuan,Dong Shuan,Shi Jia,Li Cui,Li Yuting,Zhang Yanfang,Li Haibo
Free radical biology & medicine
Sepsis caused acute lung injury (ALI) is a kind of serious disease in critically ill patients with very high morbidity and mortality. Recently, it has been demonstrated that Golgi is involved in the process of oxidative stress. However, whether Golgi stress is associated with oxidative stress in septic induced acute lung injury has not been elucidated. In this research, we found that lipopolysaccharide (LPS) induced oxidative stress, apoptosis, inflammation and Golgi morphology changes in acute lung injury both in vivo and in vitro. The knockout of heme oxygenase-1(HO-1) aggravated oxidative stress, inflammation, apoptosis and reduced the expression of Golgi matrix protein 130 (GM130), mannosidase Ⅱ, Golgi-associated protein golgin A1 (Golgin 97), and increased the expression of Golgi phosphoprotein 3 (GOLPH3), which caused the fragmentation of Golgi. Furtherly, the activation of hypoxia inducible factor-1α (HIF-1α)/HO-1 pathway, attenuates Golgi stress and oxidative stress by increasing the levels of GM130, mannosidase Ⅱ, Golgin 97, and decreasing the expression of GOLPH3 both in vivo and in vitro. Therefore, the activation of HO-1 plays a crucial role in alleviating sepsis-induced acute lung injury by regulating Golgi stress, oxidative stress, which may provide a therapeutic target for the treatment of acute lung injury.
GYY4137 alleviates sepsis-induced acute lung injury in mice by inhibiting the PDGFRβ/Akt/NF-κB/NLRP3 pathway.
Li Jianhua,Ma Jiamin,Li Mengyu,Tao Jing,Chen Jiayi,Yao Chengye,Yao Shanglong
AIMS:GYY4137 [GYY, morpholin-4-ium-4-methoxyphenyl (morpholino) phosphinodithioate] is a novel and perfect hydrogen sulfide (HS) donor that is stable in vivo and in vitro. HS, along with CO and NO, has been recognized as the third physiological gas signaling molecule that plays an active role in fighting various lung infections. However, the mechanism by which GYY4137 affects cecal ligation and puncture (CLP)-induced acute lung injury (ALI) is not understood. This study aimed to investigate whether GYY4137 inhibits the activation of the pyrin domain-containing protein 3 (NLRP3) inflammasome by inhibiting the PDGFRβ/Akt/NF-κB pathway. MAIN METHODS:The model of CLP-induced ALI was established in vivo. The mice were subsequently treated with GYY4137 (25 μg/g and 50 μg/g) to simulate the realistic conditions of pathogenesis. Western blotting and immunohistochemical staining were used to examine protein expression, hematoxylin and eosin staining was used for the histopathological analysis, and the levels of inflammatory factors were determined using enzyme-linked immunosorbent assays (ELISAs). KEY FINDINGS:GYY4137 significantly increased the 7-day survival of mice with septic peritonitis and protected against CLP-induced ALI, including decreasing neutrophil infiltration, improving sepsis-induced lung histopathological changes, diminishing lung tissue damage, and attenuating the severity of lung injury in mice. The protective effect of GYY4137 was undoubtedly dose-dependent. We discovered that GYY4137 reduced the levels of the p-PDGFRβ, p-NF-κB, ASC, NLRP3, caspase-1, and p-Akt proteins in septic mouse lung tissue. Akt regulates the generation of proinflammatory cytokines in endotoxemia-associated ALI by enhancing the nuclear translocation of NF-κB. SIGNIFICANCE:These results indicate a new molecular mechanism explaining the effect of GYY4137 on the treatment of CLP-induced ALI in mice.
The mitochondrial redistribution of eNOS is involved in lipopolysaccharide induced inflammasome activation during acute lung injury.
Wang Hui,Sun Xutong,Lu Qing,Zemskov Evgeny A,Yegambaram Manivannan,Wu Xiaomin,Wang Ting,Tang Haiyang,Black Stephen M
Acute lung injury (ALI) is a devastating clinical syndrome with no effective therapies. Inflammasome activation has been reported to play a critical role in the initiation and progression of ALI. The molecular mechanisms involved in regulating the activation of inflammasome in ALI remains unresolved, although increases in mitochondrial derived reactive oxygen species (mito-ROS) are involved. Our previous work has shown that the mitochondrial redistribution of uncoupled eNOS impairs mitochondrial bioenergetics and increases mito-ROS generation. Thus, the focus of our study was to determine if lipopolysaccharide (LPS)-mediated inflammasome activation involves the mitochondrial redistribution of uncoupled eNOS. Our data show that the increase in mito-ROS involved in LPS-mediated inflammasome activation is associated with the disruption of mitochondrial bioenergetics in human lung microvascular endothelial cells (HLMVEC) and the mitochondrial redistribution of eNOS. These effects are dependent on RhoA-ROCK signaling and are mediated via increased phosphorylation of eNOS at Threonine (T)-495. A derivative of the mitochondrial targeted Szeto-Schiller peptide (SSP) attached to the antioxidant Tiron (T-SSP), significantly attenuated LPS-mediated mito-ROS generation and inflammasome activation in HLMVEC. Further, T-SSP attenuated mitochondrial superoxide production in a mouse model of sepsis induced ALI. This in turn significantly reduced the inflammatory response and attenuated lung injury. Thus, our findings show that the mitochondrial redistribution of uncoupled eNOS is intimately involved in the activation of the inflammatory response in ALI and implicate attenuating mito-ROS as a therapeutic strategy in humans.
Nasal Delivery of Hesperidin/Chitosan Nanoparticles Suppresses Cytokine Storm Syndrome in a Mouse Model of Acute Lung Injury.
Jin Hua,Zhao Zuguo,Lan Qian,Zhou Haotong,Mai Zesen,Wang Yuan,Ding Xiaowen,Zhang Wenting,Pi Jiang,Evans Colin E,Liu Xinguang
Frontiers in pharmacology
The cytokine storm or cytokine storm syndrome (CSS) is associated with high mortality in patients with acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), for example following sepsis or infectious diseases including COVID-19. However, there are no effective treatments for CSS-associated ALI or ALI/ARDS. Thus, there remains an urgent need to develop effective drugs and therapeutic strategies against CSS and ALI/ARDS. Nasal and inhaled drug delivery methods represent a promising strategy in the treatment of inflammatory lung disease as a result of their ability to improve drug delivery to lungs. Improving the nasal mucosa absorption of poorly water-soluble drugs with poor mucosa bioavailability to a therapeutically effective level is another promising strategy in the fight against ALI/ARDS. Here, chitosan nanoparticles loaded with hesperidin (HPD/NPs) were developed for nasal delivery of the anti-inflammatory HPD compound to inflammatory lungs. and , HPD/NPs exhibited enhanced cellular uptake in the inflammatory microenvironment compared with free HPD. In a mouse model of inflammatory lung disease, the HPD/NPs markedly inhibited lung injury as evidenced by reduced inflammatory cytokine levels and suppressed vascular permeability compared with free HPD. Collectively, our study demonstrates that nasal delivery of HPD/NPs suppresses CSS and ALI/ARDS in a murine model of inflammatory lung disease, and that nanoparticle-based treatment strategies with anti-inflammatory effects could be used to reduce CSS and ALI in patients with inflammatory lung injury.
The splicing factor SRSF1 stabilizes the mRNA of TSLP to enhance acute lung injury.
Fu Chunlai,Hu Yahui,Liu Jiean,Yang You
Acute lung injury (ALI) is a severe disease with a high rate of morbidity and mortality, characterized by excessive and uncontrolled inflammatory response in lung. Recent studies demonstrated that serine arginine-rich splicing factor 1 (SRSF1) is involved in inflammation. However, whether SRSF1 modulates ALI remains to be determined. In this study, we established an ALI mouse model that induced by lipopolysaccharide (LPS), with or without the treatment of SRSF1 antibody. Our result showed that SRSF1 expression was elevated in LPS-induced ALI. Importantly, treatment with SRSF1 antibody notably ameliorated ALI in mice, as determined by reduction in lung W/D ratios, histopathological changes, lung inflammation and TSLP expression. Besides, exposure of human alveolar epithelial A549 cells to LPS enhanced the expression of both SRSF1 and TSLP, while knockdown or overexpression of SRSF1 significantly lowered or upregulated the expression of TSLP induced by LPS. Interestingly, the expression of SRSF1 and TSLP showed a positive correlation in normal human lung tissues. Mechanistically, we found that SRSF1 directly bound with the mRNA of TSLP and may exert its function by stabilizing the mRNA of TSLP in LPS-induced ALI. Therefore, our results indicated that SRSF1 may be an important contributor in lung inflammation of LPS-induced ALI and SRSF1 signaling blocking may serve as a potential treatment of ALI.
Inflammatory Caspases Drive Pyroptosis in Acute Lung Injury.
Liu Bohao,He Ruyuan,Zhang Lin,Hao Bo,Jiang Wenyang,Wang Wei,Geng Qing
Frontiers in pharmacology
Acute lung injury (ALI), a critical respiratory disorder that causes diffuse alveolar injury leads to high mortality rates with no effective treatment. ALI is characterized by varying degrees of ventilation/perfusion mismatch, severe hypoxemia, and poor pulmonary compliance. The diffuse injury to cells is one of most important pathological characteristics of ALI. Pyroptosis is a form of programmed cell death distinguished from apoptosis induced by inflammatory caspases, which can release inflammatory cytokines to clear cells infected by pathogens and promote monocytes to reassemble at the site of injury. And pyroptosis not only promotes inflammation in certain cell types, but also regulates many downstream pathways to perform different functions. There is increasing evidence that pyroptosis and its related inflammatory caspases play an important role in the development of acute lung injury. The main modes of activation of pyroptosis is not consistent among different types of cells in lung tissue. Meanwhile, inhibition of inflammasome, the key to initiating pyroptosis is currently the main way to treat acute lung injury. The review summarizes the relationship among inflammatory caspases, pyroptosis and acute lung injury and provides general directions and strategies to conduct further research.
Acute Lung Injury Causes Asynchronous Alveolar Ventilation That Can Be Corrected by Individual Sighs.
Tabuchi Arata,Nickles Hannah T,Kim Michael,Semple John W,Koch Edmund,Brochard Laurent,Slutsky Arthur S,Pries Axel R,Kuebler Wolfgang M
American journal of respiratory and critical care medicine
RATIONALE:Improved ventilation strategies have been the mainstay for reducing mortality in acute respiratory distress syndrome. Their unique clinical effectiveness is, however, unmatched by our understanding of the underlying mechanobiology, and their impact on alveolar dynamics and gas exchange remains largely speculative. OBJECTIVES:To assess changes in alveolar dynamics and associated effects on local gas exchange in experimental models of acute lung injury (ALI) and their responsiveness to sighs. METHODS:Alveolar dynamics and local gas exchange were studied in vivo by darkfield microscopy and multispectral oximetry in experimental murine models of ALI induced by hydrochloric acid, Tween instillation, or in antibody-mediated transfusion-related ALI. MEASUREMENTS AND MAIN RESULTS:Independent of injury mode, ALI resulted in asynchronous alveolar ventilation characteristic of alveolar pendelluft, which either spontaneously resolved or progressed to a complete cessation or even inversion of alveolar ventilation. The functional relevance of the latter phenomena was evident as impaired blood oxygenation in juxtaposed lung capillaries. Individual sighs (2 × 10 s at inspiratory plateau pressure of 30 cm H2O) largely restored normal alveolar dynamics and gas exchange in acid-induced ALI, yet not in Tween-induced surfactant depletion. CONCLUSIONS:We describe for the first time in detail the different forms and temporal sequence of impaired alveolar dynamics in the acutely injured lung and report the first direct visualization of alveolar pendelluft. Moreover, we identify individual sighs as an effective strategy to restore intact alveolar ventilation by a mechanism independent of alveolar collapse and reopening.
Regulation and repair of the alveolar-capillary barrier in acute lung injury.
Bhattacharya Jahar,Matthay Michael A
Annual review of physiology
Considerable progress has been made in understanding the basic mechanisms that regulate fluid and protein exchange across the endothelial and epithelial barriers of the lung under both normal and pathological conditions. Clinically relevant lung injury occurs most commonly from severe viral and bacterial infections, aspiration syndromes, and severe shock. The mechanisms of lung injury have been identified in both experimental and clinical studies. Recovery from lung injury requires the reestablishment of an intact endothelial barrier and a functional alveolar epithelial barrier capable of secreting surfactant and removing alveolar edema fluid. Repair mechanisms include the participation of endogenous progenitor cells in strategically located niches in the lung. Novel treatment strategies include the possibility of cell-based therapy that may reduce the severity of lung injury and enhance lung repair.
Aspirin-triggered 15-epi-lipoxin A4 regulates neutrophil-platelet aggregation and attenuates acute lung injury in mice.
Ortiz-Muñoz Guadalupe,Mallavia Beñat,Bins Adriaan,Headley Mark,Krummel Matthew F,Looney Mark R
Evidence is emerging that platelets are major contributors to innate immune responses in conditions such as acute lung injury (ALI). Platelets form heterotypic aggregates with neutrophils, and we hypothesized that lipoxin mediators regulate formation of neutrophil-platelet aggregates (NPA) and that NPA significantly contribute to ALI. Lipopolysaccharide (LPS)-induced lung injury was accompanied by platelet sequestration, activation, intra-alveolar accumulation, and NPA formation within both blood and alveolar compartments. Using lung intravital microscopy, we observed the dynamic formation of NPA during physiologic conditions, which sharply increased with ALI. Aspirin (ASA) treatment significantly reduced lung platelet sequestration and activation, NPA formation, and lung injury. ASA treatment increased levels of ASA-triggered lipoxin (ATL; 15-epi-lipoxin A4), and blocking the lipoxin A4 receptor (ALX) with a peptide antagonist (Boc2) or using ALX knockouts (Fpr2/3(-/-)) reversed this protection. LPS increased NPA formation in vitro, which was reduced by ATL, and engagement of ALX by ATL on both neutrophils and platelets was necessary to prevent aggregation. In a model of transfusion-related acute lung injury (TRALI), Boc2 also reversed ASA protection, and treatment with ATL in both LPS and TRALI models protected from ALI. We conclude that ATL regulates neutrophil-platelet aggregation and that platelet-neutrophil interactions are a therapeutic target in lung injury.
Increase in circulating ACE-positive endothelial microparticles during acute lung injury.
Takei Yusuke,Yamada Mitsuhiro,Saito Koji,Kameyama Yoshinobu,Sugiura Hisatoshi,Makiguchi Tomonori,Fujino Naoya,Koarai Akira,Toyama Hiroaki,Saito Kazutomo,Ejima Yutaka,Kawazoe Yu,Kudo Daisuke,Kushimoto Shigeki,Yamauchi Masanori,Ichinose Masakazu
The European respiratory journal
Circulating endothelial microparticles (EMPs) are considered to be markers of endothelial injury, and lung microvascular endothelial cells express higher levels of angiotensin-converting enzyme (ACE). The aim of this study is to examine whether the number of ACE microvascular EMPs could be a prognostic marker for the development of acute respiratory distress syndrome (ARDS) in septic patients.The numbers of EMPs and ACE EMPs in the culture supernatant from human microvascular endothelial cells, as well as in the blood of mouse lung injury models and septic patients (n=82), were examined using flow cytometry.ACE EMPs in the culture supernatant from pulmonary microvascular endothelial cells increased after exposure to an inflammatory stimulus. In the mouse lung injury models, the circulating ACE EMPs and ACE EMP/EMP ratio were higher than in the controls (p<0.001). The ACE EMP/EMP ratio was correlated with the wet/dry lung ratio (r=0.775, p<0.001). The circulating ACE EMPs and ACE EMP/EMP ratio on admission were significantly increased in septic patients who developed ARDS compared with septic patients who did not (p<0.001).Therefore, circulating ACE EMPs may be a prognostic marker for the development of ARDS in the septic patients.
T regulatory cells and dendritic cells protect against transfusion-related acute lung injury via IL-10.
Kapur Rick,Kim Michael,Aslam Rukhsana,McVey Mark J,Tabuchi Arata,Luo Alice,Liu Jonathan,Li Yuan,Shanmugabhavananthan Shanjeevan,Speck Edwin R,Zufferey Anne,Yousef George,Zhang Haibo,Rondina Matthew T,Weyrich Andrew S,Porcelijn Leendert,Kuebler Wolfgang M,Slutsky Arthur S,Semple John W
Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related fatalities and is characterized by acute respiratory distress following blood transfusion. Donor antibodies are frequently involved; however, the pathogenesis and protective mechanisms in the recipient are poorly understood, and specific therapies are lacking. Using newly developed murine TRALI models based on injection of anti-major histocompatibility complex class I antibodies, we found CD4CD25FoxP3 T regulatory cells (Tregs) and CD11c dendritic cells (DCs) to be critical effectors that protect against TRALI. Treg or DC depletion in vivo resulted in aggravated antibody-mediated acute lung injury within 90 minutes with 60% mortality upon DC depletion. In addition, resistance to antibody-mediated TRALI was associated with increased interleukin-10 (IL-10) levels, and IL-10 levels were found to be decreased in mice suffering from TRALI. Importantly, IL-10 injection completely prevented and rescued the development of TRALI in mice and may prove to be a promising new therapeutic approach for alleviating lung injury in this serious complication of transfusion.
Melatonin alleviates acute lung injury through inhibiting the NLRP3 inflammasome.
Zhang Yong,Li Xiru,Grailer Jamison J,Wang Na,Wang Mingming,Yao Jianfei,Zhong Rui,Gao George F,Ward Peter A,Tan Dun-Xian,Li Xiangdong
Journal of pineal research
Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are clinically severe respiratory disorders, and there are currently no Food and Drug Administration-approved drug therapies. Melatonin is a well-known anti-inflammatory molecule, which has proven to be effective in ALI induced by many conditions. Emerging studies suggest that the NLRP3 inflammasome plays a critical role during ALI. How melatonin directly blocks activation of the NLRP3 inflammasome in ALI remains unclear. In this study, using an LPS-induced ALI mouse model, we found intratracheal (i.t.) administration of melatonin markedly reduced the pulmonary injury and decreased the infiltration of macrophages and neutrophils into lung. During ALI, the NLRP3 inflammasome is significantly activated with a large amount of IL-1β and the activated caspase-1 occurring in the lung. Melatonin inhibits the activation of the NLRP3 inflammasome by both suppressing the release of extracellular histones and directly blocking histone-induced NLRP3 inflammasome activation. Notably, i.t. route of melatonin administration opens a more efficient therapeutic approach for treating ALI.
Neutrophils disturb pulmonary microcirculation in sepsis-induced acute lung injury.
Park Inwon,Kim Mingyo,Choe Kibaek,Song Eunjoo,Seo Howon,Hwang Yoonha,Ahn Jinhyo,Lee Seung-Hyo,Lee Jae Hyuk,Jo You Hwan,Kim Kyuseok,Koh Gou Young,Kim Pilhan
The European respiratory journal
The lung is highly vulnerable during sepsis, yet its functional deterioration accompanied by disturbances in the pulmonary microcirculation is poorly understood. This study aimed to investigate how the pulmonary microcirculation is distorted in sepsis-induced acute lung injury (ALI) and reveal the underlying cellular pathophysiologic mechanism.Using a custom-made intravital lung microscopic imaging system in a murine model of sepsis-induced ALI, we achieved direct real-time visualisation of the pulmonary microcirculation and circulating cells We derived the functional capillary ratio (FCR) as a quantitative parameter for assessing the fraction of functional microvasculature in the pulmonary microcirculation and dead space.We identified that the FCR rapidly decreases in the early stage of sepsis-induced ALI. The intravital imaging revealed that this decrease resulted from the generation of dead space, which was induced by prolonged neutrophil entrapment within the capillaries. We further showed that the neutrophils had an extended sequestration time and an arrest-like dynamic behaviour, both of which triggered neutrophil aggregates inside the capillaries and arterioles. Finally, we found that Mac-1 (CD11b/CD18) was upregulated in the sequestered neutrophils and that a Mac-1 inhibitor restored the FCR and improved hypoxaemia.Using the intravital lung imaging system, we observed that Mac-1-upregulated neutrophil aggregates led to the generation of dead space in the pulmonary microcirculation that was recovered by a Mac-1 inhibitor in sepsis-induced ALI.
Neutrophil transfer of to lung epithelial cells dampens acute lung injury in mice.
Neudecker Viola,Brodsky Kelley S,Clambey Eric T,Schmidt Eric P,Packard Thomas A,Davenport Bennett,Standiford Theodore J,Weng Tingting,Fletcher Ashley A,Barthel Lea,Masterson Joanne C,Furuta Glenn T,Cai Chunyan,Blackburn Michael R,Ginde Adit A,Graner Michael W,Janssen William J,Zemans Rachel L,Evans Christopher M,Burnham Ellen L,Homann Dirk,Moss Marc,Kreth Simone,Zacharowski Kai,Henson Peter M,Eltzschig Holger K
Science translational medicine
Intercellular transfer of microRNAs can mediate communication between critical effector cells. We hypothesized that transfer of neutrophil-derived microRNAs to pulmonary epithelial cells could alter mucosal gene expression during acute lung injury. Pulmonary-epithelial microRNA profiling during coculture of alveolar epithelial cells with polymorphonuclear neutrophils (PMNs) revealed a selective increase in lung epithelial cell expression of microRNA-223 (). Analysis of PMN-derived supernatants showed activation-dependent release of and subsequent transfer to alveolar epithelial cells during coculture in vitro or after ventilator-induced acute lung injury in mice. Genetic studies indicated that deficiency was associated with severe lung inflammation, whereas pulmonary overexpression of in mice resulted in protection during acute lung injury induced by mechanical ventilation or by infection with Studies of putative gene targets implicated repression of poly(adenosine diphosphate-ribose) polymerase-1 (PARP-1) in the -dependent attenuation of lung inflammation. Together, these findings suggest that intercellular transfer of from neutrophils to pulmonary epithelial cells may dampen acute lung injury through repression of PARP-1.
IL-33-mediated Eosinophilia Protects Against Acute Lung Injury.
Krishack Paulette A,Hollinger Maile K,Kuzel Timothy G,Decker Trevor S,Louviere Tyler J,Hrusch Cara L,Sperling Anne I,Verhoef Philip A
American journal of respiratory cell and molecular biology
Pneumonia-induced lung injury and acute respiratory distress syndrome can develop due to an inappropriate inflammatory response to acute infections, leading to a compromised alveolar barrier. Recent work suggests that hospitalized patients with allergies/asthma are less likely to die from pulmonary infections, and that there is a correlation between survival from acute respiratory distress syndrome and higher eosinophil counts; thus, we hypothesized that eosinophils associated with a type 2 immune response may protect against pneumonia-induced acute lung injury. To test this hypothesis, mice were treated with the type 2-initiating cytokine IL-33 intratracheally 3 days prior to induction of pneumonia with airway administration of a lethal dose of S. aureus. Interestingly, IL-33 pretreatment promoted survival by inhibiting acute lung injury: levels of bronchoalveolar lavage proinflammatory cytokines and pulmonary edema were both reduced, with an associated increase in oxygen saturation. Pulmonary neutrophilia was also reduced, while eosinophilia was strongly increased. This eosinophilia was key to protection; eosinophil reduction eliminated both IL-33-mediated protection against mortality as well as inhibition of neutrophilia and pulmonary edema. Together, these data reveal a novel role for eosinophils in protection against lung injury and suggest that modulation of pulmonary type 2 immunity may represent a novel therapeutic strategy.