Smoke-induced Lung Injury Research Articles

Effects of Withania somnifera (L.) Dunal in acute pulmonary pathophysiology in a rat model of smoke-induced lung injury and role of IRS-1 and SOX-2

The respiratory structure has a broad capacity to undergo the mechanism of regeneration. The recent study was intended to determine the efficacy of Withania somnifera (L.) Dunal and expression levels of IRS-1 and SOX-2 genes in the smoke-induced Pulmonary Injury. The present study included 3 groups (n = 9): Normal/negative control (NC), positive control/disease control (PC), and treatment group (TG; treated orally with 350 mg/kg of ethanol extract). Lung injury was induced in PC and TG groups in rats by cigarette smoke (4 CG/day). Decapitation (n = 3) was done on the 14th, 18th, and 21st day of treatment. Phenolic acid quantification by HPLC-UV/VIS showed a significant concentration of p-coumaric acid (130.2 mg/kg) that may also contribute to the extract's efficacy. Hematological parameters (leukocytes, hemoglobin, hematocrit) and serum oxidative parameters (total oxidant status and malondialdehyde) were significantly improved (P ≤ 0.05) in the TG compared to the PC group. Moreover, the total antioxidant capacity, total plasma protein, albumin, globulin, and platelet count significantly decreased in the PC while increasing in the treatment group (P ≤ 0.05). Histology showed damaged histological structures in the PC group, while there was obvious regeneration of architectural damage in the TG group. The IRS-1 and SOX-2 genes were up-regulated in the PC group, indicating the role of IRS-1 and SOX-2 gene expression in tissue homeostasis and regeneration in smoke-induced Pulmonary Injury. These results rationalize the traditional use of W. somnifera in pulmonary diseases and encourage further studies to exploit it in the pharmaceutical industry.

Fine particulate matter aggravates smoking induced lung injury via NLRP3/caspase-1 pathway in COPD

BackgroundExposure to noxious particles, including cigarette smoke and fine particulate matter (PM2.5), is a risk factor for chronic obstructive pulmonary disease (COPD) and promotes inflammation and cell death in the lungs. We investigated the combined effects of cigarette smoking and PM2.5 exposure in patients with COPD, mice, and human bronchial epithelial cells.MethodsThe relationship between PM2.5 exposure and clinical parameters was investigated in patients with COPD based on smoking status. Alveolar destruction, inflammatory cell infiltration, and pro-inflammatory cytokines were monitored in the smoking-exposed emphysema mouse model. To investigate the mechanisms, cell viability and death and pyroptosis-related changes in BEAS-2B cells were assessed following the exposure to cigarette smoke extract (CSE) and PM2.5.ResultsHigh levels of ambient PM2.5 were more strongly associated with high Saint George’s respiratory questionnaire specific for COPD (SGRQ-C) scores in currently smoking patients with COPD. Combined exposure to cigarette smoke and PM2.5 increased mean linear intercept and TUNEL-positive cells in lung tissue, which was associated with increased inflammatory cell infiltration and inflammatory cytokine release in mice. Exposure to a combination of CSE and PM2.5 reduced cell viability and upregulated NLRP3, caspase-1, IL-1β, and IL-18 transcription in BEAS-2B cells. NLRP3 silencing with siRNA reduced pyroptosis and restored cell viability.ConclusionsPM2.5 aggravates smoking-induced airway inflammation and cell death via pyroptosis. Clinically, PM2.5 deteriorates quality of life and may worsen prognosis in currently smoking patients with COPD.Graphical

Lavandula stoechas significantly alleviates cigarette smoke-induced acute lung injury via modulation of oxidative stress and the NF-κB pathway

Cigarette smoke (CS) is one of the major triggering factorsfor oxidative stress and contributes to development of acute lung injury and acute respiratory distress syndrome (ALI/ARDS), both of which are marked by severe lung inflammation. Due to the absence of viable treatment options for ALI/ARDS, methanolic extract of Lavandula stoechas (Ls.Met) was used to evaluate the protective effect against CS-induced ALI in both in vivo and in vitro settings.In order to prepare CS-induced ALI murine models, male Swiss albino mice were exposed to whole-body CS for 10 days. Normal saline (10 mL/kg), Ls.Met (250, 450, 750 mg/kg), and dexamethasone (1 mg/kg) were administered orally to respective animal groups (n = 5/group) 1 h prior to CS-exposure. Twenty-four hrs following the last CS-exposure, bronchoalveolar lavage fluid (BALF) and lungs were harvested to examine the important aspects of ALI. Subsequently, in vitro protective effect of Ls.Met (10 and 100 μM) was assessed against 4% CSE (for 24 h)-stimulated RAW 264.7 macrophages.The presence of phenols and flavonoids was verified by HPLC analysis. Ls.Met dose-dependently and remarkably reduced macrophages and neutrophil invasion into the lungs, lung weight coefficient, albumin exudates into the alveoli, and improved hypoxemia and lung histopathological alterations. Notably, Ls.Met attenuated the CS-induced oxidative stress as evidenced by decreased levels of malondialdehyde, total oxidant status (TOS), and myeloperoxidas, alongside enhanced total antioxidant capacity (TAC) production. Moreover, Ls.Met demonstrated a marked reduction in CS-induced overexpression of proinflammatory cytokines (IL-6, IL-1β, and KC) and inhibited the activation of NF-κB, a key signalling pathway involved in inflammation. Lavandula stoechas could thus be a potential therapeutic option for the treatment of CS-induced ALI.

Quantitative proteome and lysine succinylome characterization of zinc chloride smoke-induced lung injury in mice

The inhalation of zinc chloride (ZnCl2) smoke is one of common resources of lung injury, potentially resulting in severe pulmonary complications and even mortality. The influence of ZnCl2 smoke on lysine succinylation (Ksucc) in the lungs remains uncertain. In this study, we used a ZnCl2 smoke inhalation mouse model to perform global proteomic and lysine succinylome analyses. A total of 6781 Ksucc sites were identified in the lungs, with injured lungs demonstrating a reduction to approximately 2000 Ksucc sites, and 91 proteins exhibiting at least five differences in the number of Ksucc sites. Quantitative analysis revealed variations in expression of 384 proteins and 749 Ksucc sites. The analysis of protein-protein interactions was conducted for proteins displaying differential expression and differentially expressed lysine succinylation. Notably, proteins with altered Ksucc exhibited increased connectivity compared with that in differentially expressed proteins. Beyond metabolic pathways, these highly connected proteins were also involved in lung injury-associated pathological reactions, including processes such as focal adhesion, adherens junction, and complement and coagulation cascades. Collectively, our findings contribute to the understanding of the molecular mechanisms underlaying ZnCl2 smoke-induced lung injury with a specific emphasis on lysine succinylation. These findings could pave the way for targeted interventions and therapeutic strategies to mitigate severe pulmonary complications and mortality associated with such injuries in humans.

Naringenin regulates cigarette smoke extract-induced extracellular vesicles from alveolar macrophage to attenuate the mouse lung epithelial ferroptosis through activating EV miR-23a-3p/ACSL4 axis

BackgroundAlveolar macrophages are one of the momentous regulators in pulmonary inflammatory responses, which can secrete extracellular vesicles (EVs) packing miRNAs. Ferroptosis, an iron-dependent cell death, is associated with cigarette smoke-induced lung injury, and EVs have been reported to regulate ferroptosis by transporting intracellular iron. However, the regulatory mechanism of alveolar macrophage-derived EVs has not been clearly illuminated in smoking-related pulmonary ferroptosis. Despite the known anti-ferroptosis effects of naringenin in lung injury, whether naringenin controls EVs-mediated ferroptosis has not yet been explored. PurposeWe explore the effects of EVs from cigarette smoke-stimulated alveolar macrophages in lung epithelial ferroptosis, and elucidate the EV miRNA-mediated pharmacological mechanism of naringenin. Study design and methodsDifferential and ultracentrifugation were conducted to extract EVs from different alveolar macrophages treatment groups in vitro. Both intratracheal instilled mice and treated epithelial cells were used to investigate the roles of EVs from alveolar macrophages involved in ferroptosis. Small RNA sequencing analysis was performed to distinguish altered miRNAs in EVs. The ferroptotic effects of EV miRNAs were examined by applying dual-Luciferase reporter assay and miRNA inhibitor transfection experiment. ResultsHere, we firstly reported that EVs from cigarette smoke extract-induced alveolar macrophages (CSE-EVs) provoked pulmonary epithelial ferroptosis. The ferroptosis inhibitor ferrostatin-1 treatment reversed these changes in vitro. Moreover, EVs from naringenin and CSE co-treated alveolar macrophages (CSE+Naringenin-EVs) markedly attenuated the lung epithelial ferroptosis compared with CSE-EVs. Notably, we identified miR-23a-3p as the most dramatically changed miRNA among Normal-EVs, CSE-EVs, and CSE+Naringenin-EVs. Further experimental investigation showed that ACSL4, a pro-ferroptotic gene leading to lipid peroxidation, was negatively regulated by miR-23a-3p. The inhibition of miR-23a-3p diminished the efficacy of CSE+Naringenin-EVs. ConclusionOur findings firstly provided evidence that naringenin elevated the EV miR-23a-3p level from CSE-induced alveolar macrophages, thereby inhibiting the mouse lung epithelial ferroptosis via targeting ACSL4, and further complemented the mechanism of cigarette-induced lung injury and the protection of naringenin in a paracrine manner. The administration of miR-23a-3p-enriched EVs has the potential to ameliorate pulmonary ferroptosis.

Cichorium intybus L. significantly alleviates cigarette smoke-induced acute lung injury by lowering NF-κB pathway activation and inflammatory mediators

BackgroundCigarette smoke (CS) is one of the primary causes of acute lung injury (ALI) via provoking pulmonary inflammation and oxidative stress. Despite substantial studies, no effective treatment for ALI is presently available. PurposeNew prospective treatment options for ALI are required. Thus, this project was designed to investigate the in vivo and in vitro protective effects of 70 % methanolic-aqueous crude extract of whole plant of Cichorium intybus (Ci.Mce) against CS-induced ALI. Study design/methods: Initially, male Swiss albino mice were subjected to whole-body CS exposure for 10 continuous days to prepare CS-induced ALI models. Normal saline (10 mL/kg), Ci.Mce (100, 200, 300 mg/kg), and Dexamethasone (1 mg/kg) were orally administered to respective animal groups 1 h prior to CS-exposure. 24 hrs after the last CS-exposure, BALF and lungs were harvested to study the key characteristics of ALI. Next, HPLC analysis was done to explore the phytoconstituents. ResultsCi.Mce exhibited significant reductions in lung macrophage and neutrophil infiltration, lung weight coefficient, and albumin exudation. Additionally, it effectively ameliorated lung histopathological alterations and hypoxemia. Notably, Ci.Mce exerted inhibitory effects on the excessive generation of IL-6, IL-1β, and KC in both CS-induced ALI murine models and CSE-stimulated RAW 264.7 macrophages. Noteworthy benefits included the attenuation of oxidative stress induced by CS, evidenced by decreased levels of MDA, TOS, and MPO, alongside enhanced TAC production. Furthermore, Ci.Mce demonstrated a marked reduction in CS-induced NF-κB expression, both in vivo and in vitro. ConclusionConsequently, Cichorium intybus could be a therapeutic option for CS-induced ALI due to its ability to suppress inflammatory reactions, mitigate oxidative stress, and quell NF-κB p65 activation.

Vardenafil alleviates cigarette smoke-induced chronic obstructive pulmonary disease by activating autophagy via the AMPK/mTOR signalling pathway: an in vitro and in vivo study.

Chronic obstructive pulmonary disease (COPD) has always attracted global attention with its high prevalence, incidence rate, and mortality. Exposure to cigarette smoke is one of main causes of COPD. Therefore, it is still necessary to study its pathogenesis and find new therapeutic strategies for early COPD prevention and treatment. Vardenafil, a type 5 phosphodiesterase (PDE5) inhibitor, is known to have an efficient therapy in some cardiovascular, pulmonary, and vascular diseases, which is an important mechanism for COPD. However, it still loss relevant research on whether vardenafil is effective in COPD and its mechanism. In this study, the cigarette smoke inhalation was performed to establish cigarette smoke-induced COPD model using C57BL/6 mice and 16HBE cells were treated with cigarette smoke extract (CSE). Mice were treated with vardenafil for 30 d. Then condition of lung injury was evaluated using histological analysis. The content of cytokines and the number of inflammatory cells in lung tissues or bronchoalveolar lavage fluid were measured. Additionally, western blot analysis was employed to evaluate the activation of adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK)/mechanistic target of rapamycin (mTOR)-mediated autophagy in vitro. The results showed that vardenafil abolished CSE's effect by activating autophagy via the AMPK/mTOR signalling pathway in vitro. Vardenafil attenuated cigarette smoke-induced lung injury and inflammation response by activating autophagy via the AMPK/mTOR signalling pathway in vivo. These results provide valuable insights into the molecular mechanisms underlying vardenafil's beneficial effects in cigarette smoke-induced COPD treatment. In conclusion, vardenafil alleviates cigarette smoke-induced experimental COPD by activating autophagy via the AMPK/mTOR signalling pathway.

The role of transforming growth factor-β2 in cigarette smoke-induced lung inflammation and injury.

Transforming growth factor-β2 (TGF-β2) plays an important role in pleiotropic functions and has been reported to be involved in the pathogenesis of chronic obstructive lung disease. The role of TGF-β2 in regulating cigarette smoke (CS)-induced lung inflammation and injury has not been investigated, and its underlying mechanism remains unclear. Primary bronchial epithelial cells (PBECs) were treated with cigarette smoke extract (CSE), and the signaling pathway of TGF-β2 regulating lung inflammation was investigated. Mice were exposed to CS and treated with TGF-β2 i.p. or bovine whey protein extract containing TGF-β2 p.o., and the role of TGF-β2 in alleviating lung inflammation/injury was studied. In vitro, we demonstrated that TGF-β2 attenuated CSE-induced IL-8 production from PBECs through the TGF-β receptor I (TGF-βRI), Smad3, and mitogen-activated protein kinase signaling pathways. Selective TGF-βRI inhibitor (LY364947) and antagonist of Smad3 (SIS3) abolished the effect of TGF-β2 on alleviating CSE-induced IL-8 production. In vivo, CS exposure for 4weeks in mice increased the levels of total protein, inflammatory cell counts, and monocyte chemoattractant protein-1 in bronchoalveolar fluid and induced lung inflammation/injury, as revealed by immunohistochemistry. Administration of TGF-β2 through intraperitoneal injection or oral feeding with bovine whey protein extract containing TGF-β2 significantly reduced CS-induced lung inflammation and injury. We concluded that TGF-β2 reduced CSE-induced IL-8 production through the Smad3 signaling pathway in PBECs and alleviated lung inflammation/injury in CS-exposed mice. The anti-inflammatory effect of TGF-β2 on CS-induced lung inflammation in humans deserves further clinical study.

Analyzing cross-talk of EPO and EGF genes along with evaluating therapeutic potential of Cinnamomum verum in cigarette-smoke-induced lung pathophysiology in rat model.

The integrity of the distal alveolar epithelium is crucial for lung regeneration following an injury. The present study aimed to evaluate the effect of Cinnamomum verum extract; cross-talk of epidermal growth factor (EGF) and erythropoietin (EPO) genes in a smoke-induced lung injury rat model. For experimentation (n=27), albino rats were divided equally into three groups, i.e., negative control (NC), positive control (PC), and treatment group (TG). Cigarette smoke was exposed to PC and TG (4 CG/day). C. verum was given orally (350 mg/kg body weight) for 21 days. Decapitation (n=3) was done on 14th, 18th, and 21st days, respectively. Analyses (hematology, biochemical, high performance liquid chromatography [HPLC], histology, and gene expression) were carried out and results were statistically analyzed by two-way analysis of variance. HPLC analysis of ethanolic extract of C. verum was done to identify the presence of phenolic constituents which showed high concentrations of quercetin and P-coumaric acid. Serum oxidative parameters such as total oxidant status, malondialdehyde, and hematological parameters such as red blood cells, hemoglobin, hematocrit, and white blood cells were significantly (p < .05) elevated in the PC group; however, these parameters were significantly (p < .05) improved in TG. While total antioxidant capacity and serum parameters such as total protein, albumin, and globulin were significantly (p < .05) reduced in the PC group but significantly improved (p < .05) in TG. Histological analysis revealed that smoke exposure resulted in a measurable increase in alveolar septal thickening while ethanolic extract of C. verum greatly ameliorated the histopathological changes in the lung alveoli. The gene expression analysis of EGF and EPO genes showed a significant upregulation (p < .05) of both genes in PC group while in TG, the level of both genes downregulated, in which lung damage was ameliorated due to cytoprotective effects of ethanolic extract of C. verum.

LncRNA MALAT1 Participates in Protection of High-Molecular-Weight Hyaluronan against Smoke-Induced Acute Lung Injury by Upregulation of SOCS-1.

Smoke-induced acute lung injury (ALI) is a grievous disease with high mortality. Despite advances in medical intervention, no drug has yet been approved by the Food and Drug Administration (FDA) for ALI. In this study, we reported that pretreatment with high-molecular-weight hyaluronan (1600 kDa, HA1600) alleviated pulmonary inflammation and injury in mice exposed to smoke and also upregulated long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), as well as suppressor of cytokine signaling-1 (SOCS-1), in the lung tissues. Next, we overexpressed MALAT1 in the lungs by intratracheal administration of adenovirus cloned with MALAT1 cDNA and found that the survival of mice after smoke exposure was improved. Moreover, pulmonary overexpression of MALAT1 ameliorated smoke-induced ALI in mice and elevated the level of SOCS-1 in the lungs. In conclusion, the results pointed out that HA1600 exerted a protective effect against smoke-induced ALI through increasing the MALAT1 level and the subsequent SOCS-1 expression. Our study provides a potential therapeutic approach to smoke-induced ALI and a novel insight into the mechanism of action of HA1600.

Inhaled D-Limonene minimizes acute lung injury and reduces oxidative stress induced by smoke in rats

BackgroundDespite some advances in the discovery of novel therapies, smoke inhalation injury remains a difficult to treat critical health issue due to its physiopathological complexity. Natural products, such as d-limonene (LIM), are becoming an important potential source of new treatments in many health problems. LIM has been shown to have antioxidant, anti-inflammatory and protective effects in respect of several diseases, including respiratory conditions. ObjectiveThe aim of this study was to evaluate the effects of inhaled LIM on acute smoke-induced lung injury in rats. MethodsThirty minutes after smoke inhalation, adult male Wistar rats were treated with vehicle or LIM (0.01 mg/kg) for 30 min. Blood samples, and the liver, lungs, and trachea were collected for analysis. ResultsThe results showed that LIM minimized the injuries, reducing oxidative and inflammatory damage by improving catalase (CAT) (p < 0.05), and superoxide dismutase (SOD) activities (trachea: p < 0.01; lung: p < 0.05) and reducing interleukin-1 beta (IL-1β) level (p < 0.01) caused by smoke inhalation. LIM was also able to ameliorate damage in both trachea and lung tissues. ConclusionsThe results indicate that LIM has a beneficial effect on lung injury, mainly by reducing oxidative stress, anti-inflammatory response and tissue damage.

Pulmonary delivery of resveratrol-β-cyclodextrin inclusion complexes for the prevention of zinc chloride smoke-induced acute lung injury

Smoke bombs are often used in military/fire training, which can produce a large amount of zinc chloride (ZnCl2) smoke. Inhalation of ZnCl2 smoke usually causes acute lung injury (ALI) that would likely develop to acute respiratory distress syndrome (ARDS). However, there is no effective prevention or treatment strategy for the smoke-induced ALI. Resveratrol (RES) is a natural polyphenol with good anti-inflammatory and anti-apoptotic activities, but its low solubility, stability, and bioavailability restrict its clinical application. In this study, an inhalable RES formulation composed of RES-β-cyclodextrin inclusion complexes (RES-β-CD) was prepared for the prevention of ZnCl2 smoke-induced ALI. RES-β-CD powders had a small mass median aerodynamic diameter of 3.61 μm and a high fine particle fraction of 38.84%, suitable for pulmonary inhalation. RES-β-CD exhibited low BEAS-2B cytotoxicity. Pulmonary delivery of RES-β-CD to mice remarkably prevented the smoke-induced ALI with downregulation of TNF-α, IL-1β, STAT3, and GATA3, and upregulation of T-bet and Foxp3. RES-β-CD protected the respiratory function, percutaneous oxygen saturation, physical activity, lung capillary integrity, and lung liquid balance, alleviating inflammation and apoptosis. Pulmonary delivery of the positive drug, budesonide (BUD), also alleviated the smoke-induced ALI by reduction of inflammation and cell apoptosis. RES-β-CD exhibited the regulation of the Th1/Th2 and Treg/Th17 balances, while BUD did not show any effect on immune balances. In conclusion, pulmonary delivery of RES-β-CD is a promising anti-inflammatory and anti-apoptosis strategy for the prevention of ZnCl2 smoke-induced ALI by direct lung drug distribution and regulation of immune balance.

Ninjinyoeito ameliorated cigarette smoke extract-induced apoptosis and inflammation through JNK signaling inhibition in human lung fibroblasts

BackgroundCigarette smoke is a major risk factor for various lung diseases, such as chronic obstructive pulmonary disease (COPD). Ninjinyoeito (NYT), a traditional Chinese medicine, has been prescribed for patients with post-illness or post-operative weakness, fatigue, loss of appetite, rash, cold limbs, and anemia. In addition to its traditional use, NYT has been prescribed for treating frailty in gastrointestinal, respiratory, and urinary functions. Further, NYT treatment can ameliorate cigarette smoke-induced lung injury, which is a destructive index in mice; however, the detailed underlying mechanism remains unknown. The purpose of this study was to investigate whether NYT ameliorates cigarette smoke-induced cell injury and inflammation in human lung fibroblasts and determine its mechanism of action.MethodsWe prepared a cigarette smoke extract (CSE) from commercially available cigarettes to induce cell injury and inflammation in the human lung fibroblast cell line HFL1. The cells were pretreated with NYT for 24 h prior to CSE exposure. Cytotoxicity and cell viability were measured by lactate dehydrogenase (LDH) cytotoxicity assay and cell counting kit (CCK)-8. IL-8 level in the cell culture medium was measured by performing Enzyme-Linked Immuno Sorbent Assay (ELISA). To clarify the mechanisms of NYT, we used CellROX Green Reagent for reactive oxygen species (ROS) production and western blotting analysis for cell signaling.ResultsExposure of HFL1 cells to CSE for 24 h induced apoptosis and interleukin (IL)-8 release. Pretreatment with NYT inhibited apoptosis and IL-8 release. Furthermore, CSE exposure for 24 h increased the production of ROS and phosphorylation levels of p38 and JNK. Pretreatment with NYT only inhibited CSE-induced JNK phosphorylation, and not ROS production and p38 phosphorylation. These results suggest that NYT acts as a JNK-specific inhibitor.ConclusionNYT treatment ameliorated CSE-induced apoptosis and inflammation by inhibiting the JNK signaling pathway. Finally, these results suggest that NYT may be a promising therapeutic agent for patients with COPD.

Exosomes derived from adipose-derived stem cells alleviate cigarette smoke-induced lung inflammation and injury by inhibiting alveolar macrophages pyroptosis

BackgroundChronic obstructive pulmonary disease (COPD) is a frequently encountered disease condition in clinical practice mainly caused by cigarette smoke (CS). The aim of this study was to investigate the protective roles of human adipose-derived stem cells-derived exosomes (ADSCs-Exo) in CS-induced lung inflammation and injury and explore the underlying mechanism by discovering the effects of ADSCs-Exo on alveolar macrophages (AMs) pyroptosis.MethodsADSCs were isolated from human adipose tissues harvested from three healthy donors, and then ADSCs-Exo were isolated. In vivo, 24 age-matched male C57BL/6 mice were exposed to CS for 4 weeks, followed by intratracheal administration of ADSCs-Exo or phosphate buffered saline. In vitro, MH-S cells, derived from mouse AMs, were stimulated by 2% CS extract (CSE) for 24 h, followed by the treatment of ADSCs-Exo or phosphate buffered saline. Pulmonary inflammation was analyzed by detecting pro-inflammatory cells and mediators in the bronchoalveolar lavage fluid. Lung histology was assessed by hematoxylin and eosin staining. Mucus production was determined by Alcian blue-periodic acid-Schiff staining. The profile of AMs pyroptosis was evaluated by detecting the levels of pyroptosis-indicated proteins. The inflammatory response in AMs and the phagocytic activity of AMs were also investigated.ResultsIn mice exposed to CS, the levels of pro-inflammatory cells and mediators were significantly increased, mucus production was markedly increased and lung architecture was obviously disrupted. AMs pyroptosis was elevated and AMs phagocytosis was inhibited. However, the administration of ADSCs-Exo greatly reversed these alterations caused by CS exposure. Consistently, in MH-S cells with CSE-induced properties modelling those found in COPD, the cellular inflammatory response was elevated, the pyroptotic activity was upregulated while the phagocytosis was decreased. Nonetheless, these abnormalities were remarkably alleviated by the treatment of ADSCs-Exo.ConclusionsADSCs-Exo effectively attenuate CS-induced airway mucus overproduction, lung inflammation and injury by inhibiting AMs pyroptosis. Therefore, hADSCs-Exo may be a promising cell-free therapeutic candidate for CS-induced lung inflammation and injury.

Knockdown of circFOXO3 ameliorates cigarette smoke-induced lung injury in mice

BackgroundChronic obstructive pulmonary disease (COPD) remains a prevalent chronic airway inflammatory disease. Circular RNAs (circRNAs) are associated with inflammation regulation; therefore, we examined distinct effects of circRNA FOXO3 (circFOXO3) against pneumonic inflammatory processes in COPD.MethodsWe first quantified and localized circFOXO3 in mouse lung epithelial cell line MLE12 by quantitative reverse-transcription PCR and in situ hybridization. Next, circFOXO3 was suppressed by therapeutic administration of circFOXO3 knockdown lentivirus in mice exposed to air or cigarette smoke (CS) for 12 weeks, and several hallmarks of COPD were evaluated.ResultsWe noticed that circFOXO3 is upregulated in CS-exposed lungs and cigarette smoke extract (CSE)-treated murine alveolar epithelial cells. Knockdown of circFOXO3 attenuated the release of CXCL1 and IL-6 as well as inflammatory processes in the lungs of CS-exposed mice. In addition, we identified miR-214-3p as a circFOXO3-targeted microRNA. MiR-214-3p overexpression exerted protective effects against pneumonic inflammation after CS exposure. Silencing of circFOXO3 downregulated IKK-β mRNA (miR-214-3p’s target), resulting in the dysfunction of the NF-κB signaling pathway and attenuation of CSE-induced inflammatory-cytokine expression.ConclusionsCollectively, these findings reveal a crucial function of circFOXO3 in the pathological remodeling related to CS-induced inflammatory processes. Hence, circFOXO3 might be a good target for the treatment of inflammatory disorders similar to CS-induced lung inflammation.

Therapeutic effect and underlying mechanism of exosomes from human adipose-derived stem cells on smoke-induced inflammation and lung injury in mice

Therapeutic effect and underlying mechanism of exosomes from human adipose-derived stem cells on smoke-induced inflammation and lung injury in mice

Measurement of urinary Dickkopf-3 uncovered silent progressive kidney injury in patients with chronic obstructive pulmonary disease

Chronic kidney disease (CKD) represents a global public health problem with high disease related morbidity and mortality. Since CKD etiology is heterogeneous, early recognition of patients at risk for progressive kidney injury is important. Here, we evaluated the tubular epithelial derived glycoprotein dickkopf-3 (DKK3) as a urinary marker for the identification of progressive kidney injury in a non-CKD cohort of patients with chronic obstructive pulmonary disease (COPD) and in an experimental model. In COSYCONET, a prospective multicenter trial comprising 2,314 patients with stable COPD (follow-up 37.1 months), baseline urinary DKK3, proteinuria and estimated glomerular filtration rate (eGFR) were tested for their association with the risk of declining eGFR and the COPD marker, forced expiratory volume in one second. Baseline urinary DKK3 but not proteinuria or eGFR identified patients with a significantly higher risk for over a 10% (odds ratio: 1.54, 95% confidence interval: 1.13-2.08) and over a 20% (2.59: 1.28-5.25) decline of eGFR during follow-up. In particular, DKK3 was associated with a significantly higher risk for declining eGFR in patients with eGFR over 90 ml/min/1.73m2 and proteinuria under 30 mg/g. DKK3 was also associated with declining COPD marker (2.90: 1.70-4.68). The impact of DKK3 was further explored in wild-type and Dkk3-/- mice subjected to cigarette smoke-induced lung injury combined with a CKD model. In this model, genetic abrogation of DKK3 resulted in reduced pulmonary inflammation and preserved kidney function. Thus, our data highlight urinary DKK3 as a possible marker for early identification of patients with silent progressive CKD and for adverse outcomes in patients with COPD.

Edaravone combined with dexamethasone exhibits synergic effects on attenuating smoke-induced inhalation lung injury in rats

Inhalational lung injury often leads to morbidity and mortality during fire disasters. In this study, we aimed to evaluate the protective effects of edaravone combined with dexamethasone on smoke-induced inhalational lung injury. Sprague-Dawley rats were divided into five groups, namely, the control, model (inhalation), and three treatment groups (edaravone, dexamethasone, and edaravone combined with dexamethasone). After drug intervention in the acute lung injury model, arterial blood gas, wet:dry weight ratio of the lung tissue, bronchoalveolar lavage fluid, and pulmonary histopathology were determined. The production of reactive oxygen species (ROS), mitochondrial membrane potential (MMP), inflammatory cytokines, peroxidase and apoptosis were further analyzed to explore the underlying mechanisms. The results of blood gas and inflammatory cytokine analysis and the histopathological data demonstrated that edaravone combined with dexamethasone had obvious protective effects on smoke infiltration and tissue injury. Moreover, after the co-administration of edaravone and dexamethasone, malondialdehyde and myeloperoxidase levels in the lung tissue decreased, whereas those of glutathione peroxidase and superoxide dismutase were elevated. In addition, this drug combination could inhibit smoke-induced apoptosis in lung tissues by reducing the cleavage of caspase-3, caspase-9, and poly ADP-ribose polymerase (PARP), and also reverse smoke-mediated mitochondrial dysfunction, including ROS generation, loss of MMP, early release of cytochrome C, second mitochondrial activator of caspases, and apoptosis-inducing factor. In conclusion, edaravone combined with dexamethasone had a protective effect on smoke-induced inhalational lung injury in rats and can be further explored as an attractive therapeutic option for the treatment of smoke inhalation-induced pulmonary dysfunction.

Increased serum SP-D in identification of high-risk smokers at high risk of COPD.

Pulmonary surfactant protein D (SP-D) is an important component of the pulmonary innate immune system with the ability to dampen cigarette smoke-induced lung inflammation. However, cigarette smoking mediates translocation of SP-D from the lung to the blood, and serum SP-D (sSP-D) has therefore previously been suggested as marker for smoke-induced lung injury. In support of this notion, associations between high sSP-D and low lung function measurements have previously been demonstrated in smokers and in chronic obstructive lung disease (COPD). The present investigations employ a 12-yr longitudinal Danish twin study to test the hypothesis that baseline sSP-D variation has the capacity to identify smokers with normal baseline lung function who are at high risk of significant future smoke-induced lung function decline. We find that sSP-D is significantly increased in those with normal lung function at baseline who develop lung function decline during follow-up compared with those who stay lung healthy. Moreover, we demonstrate that it is the smoke-induced baseline sSP-D level, and not the constitutional level, which has capacity as biomarker, and which is linearly increased with the decline in lung function during follow-up. In conclusion, we here present first observation of increased sSP-D for identification of high-risk smokers.

Knockdown of Alpha-1 Antitrypsin with antisense oligonucleotide does not exacerbate smoke induced lung injury

Alpha-1 Antitrypsin (AAT) is a serum protease inhibitor that regulates increased lung protease production induced by cigarette smoking. Mutations in the Serpina1 gene cause AAT to form hepatoxic polymers, which can lead to reduced availability for the protein’s primary function and severe liver disease. An AAT antisense oligonucleotide (ASO) was previously identified to be beneficial for the AATD liver disease by blocking the mutated AAT transcripts. Here we hypothesized that knockdown of AAT aggravates murine lung injury during smoke exposure and acute exacerbations of chronic obstructive pulmonary disease (COPD). C57BL/6J mice were randomly divided into 4 groups each for the smoking and smoke-flu injury models. The ASO and control (No-ASO) were injected subcutaneously starting with smoking or four days prior to influenza infection and then injected weekly at 50 mg/kg body weight. ASO treatment during a 3-month smoke exposure significantly decreased the serum and lung AAT expression, resulting in increased Cela1 expression and elastase activity. However, despite the decrease in AAT, neither the inflammatory cell counts in the bronchoalveolar lavage fluid (BALF) nor the lung structural changes were significantly worsened by ASO treatment. We observed significant differences in inflammation and emphysema due to smoke exposure, but did not observe an ASO treatment effect. Similarly, with the smoke-flu model, differences were only observed between smoke-flu and room air controls, but not as a result of ASO treatment. Off-target effects or compensatory mechanisms may account for this finding. Alternatively, the reduction of AAT with ASO treatment, while sufficient to protect from liver injury, may not be robust enough to lead to lung injury. The results also suggest that previously described AAT ASO treatment for AAT mutation related liver disease may attenuate hepatic injury without being detrimental to the lungs. These potential mechanisms need to be further investigated in order to fully understand the impact of AAT inhibition on protease-antiprotease imbalance in the murine smoke exposure model.