Lung Cell Apoptosis Research Articles

Chest X-ray Image Analysis and Penehyclidine Hydrochloride Postconditioning Influence of Lung Ischemia Reperfusion Injury

Purpose: We analyze chest X-ray diagnosis results of patients undergoing cardiopulmonary bypass heart surgery in intensive care unit (ICU). In our previous study, we found that penehyclidine hydrochloride (PHC) preconditioning pretects lung function and reduced the apoptosis. Although preconditioning is effective, this clinical treatment is often given only when symptoms appear, when postconditioning is easier to administer. In this study, after confirming the lung condition via medical image analysis, we aimed to look the effect of high-dose penehyclidine hydrochloride postconditioning in lung after I/R in rats, and the apoptosis mechanisms involved. Methods: Chest X-ray was taken in 256 adult patients under cardiopulmonary bypass with heart syurery. Medical image analysis was preliminarily performed, the diagnostic results were analyzed. Rats were subjected to ischemia in left lung 45 min, and then 2 h reperfusion, and treated with PHC. We then observed the effects of PHC on the following: lung function, lung injury, oxidative stress, rate of apoptosis of lung cells, apoptosis-related proteins, and the p38 MAPK pathway. Results: Analysis results of chest X-ray suggest multiple pulmonary complications after cardiopulmonary bypass heart surgery. The laboratory results showed that high-dose penehyclidine hydrochloride postconditioning significantly protected lung function, reduced oxidative stress and apoptosis of the lungs caused by reperfusion, and inhibited activation of the p38 MAPK pathway. Conclusion: Analysis results of chest X-ray show multiple pulmonary complications after cardiopulmonary bypass heart surgery. This study suggests that high-dose penehyclidine hydrochloride can treat lung I/R injury.

RETRACTED: LncRNA NEAT1 acts as a key regulator of cell apoptosis and inflammatory response by the miR-944/TRIM37 axis in acute lung injury

Acute lung injury (ALI), a common complication of sepsis, is characterized by the impairment and injury of pulmonary function. The nuclear factor kappa-B (NF-κB) pathway is activated in ALI. Tripartite motif-containing 37 (TRIM37) can activate the NF-κB pathway and is closely associated with inflammation. The purpose of our study is to reveal the role of TRIM37 in ALI. The present study revealed that TRIM37 presented high levels in lung tissues of ALI mice, and knockdown of TRIM37 alleviated lipopolysaccharide (LPS)-induced lung injury, inflammatory response, and cell apoptosis invivo. In addition, knockdown of TRIM37 inhibited the inflammatory response, and cell apoptosis of LPS-treated WI-38cells. Mechanistically, miR-944 was identified to bind with and negatively regulate TRIM37. Furthermore, NEAT1 was indicated to act as a competitive endogenous RNA to promote TRIM37 expression by sequestering miR-944. Detailly, NEAT1 bound with miR-944, negatively modulated miR-944 expression, and positively modulated TRIM37 expression. The rescue assays suggested that overexpression of TRIM37 rescued the influence of NEAT1 knockdown on cell apoptosis and inflammatory response. Overall, NEAT1 facilitated cell apoptosis and inflammatory response of WI-38cells by the miR-944/TRIM37 axis in sepsis-induced ALI, implying that NEAT1 may provide a novel insight for the treatment of sepsis-induced ALI.

Long non-coding RNA maternally expressed gene regulates cigarette smoke extract induced lung inflammation and human bronchial epithelial apoptosis via miR-149-3p.

Chronic obstructive pulmonary disease (COPD) has become a significant public health risk. Long non-coding RNAs (lncRNAs) have been identified as important factors involved in the proliferation, apoptosis and inflammatory cytokine expression of lung cells. Peripheral blood samples from 66 subjects (18 non-smokers, 24 smokers without COPD and 28 smokers with COPD) and HBE135-E6E7 cell treated with cigarette smoke extract (CSE) or not were used as the research object. The aim of the present study was to investigate the underlying mechanism of lncRNA maternally expressed gene 3 (MEG3) in COPD. Following transfection with microRNA (miR)-149-3p mimics, miR-negative control mimics, miR-149-3p inhibitor, miR-negative control inhibitor, small interfering (si)RNA targeting MEG3 (si-MEG3) and si-negative control (si-NC), levels of MEG3 and microRNA (miR)-149-3p were detected using reverse transcription-quantitative PCR, Proliferation and apoptosis were examined using the Cell Counting Kit-8 and flow cytometry assays, respectively. Enzyme-linked immunosorbent assay (ELISA) was performed to detect the expression of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Protein levels of B-cell lymphoma-2 (Bcl-2), cleaved-caspase-3, cleaved-caspase-9, phosphorylated (p)-p65, total (t)-p65, p-lkBα and t-lkBα were measured by western blotting. Luciferase assay was conducted to examine the relationship between MEG3 and miR-149-3p. LncRNA MEG3 was highly expressed, whereas miR-149-3p expression was downregulated in smokers with COPD peripheral blood samples, compared with non-smokers and smokers without COPD samples. Compared with untreated human bronchial epithelial (HBE) cells, MEG3 expression was increased in cigarette smoke extract (CSE)-treated HBE cells. Compared with CSE-treated HBE cells transfected with si-NC, MEG3 knockdown promoted cell proliferation and inhibited apoptosis in CSE-treated HBE cells transfected with si-MEG3, and it also decreased the levels of IL-6, TNF-α, Bcl-2 and increased cleaved-caspase-3 and cleaved-caspase-9 in CSE-treated HBE cells transfected with si-MEG3. The luciferase assay demonstrated that miR-149-3p has target sites for MEG3. MEG3 was demonstrated to regulate the NF-κB signaling pathway by sponging miR-149-3p in CSE-treated HBE cells. In conclusion, these findings suggested that MEG3 promoted proliferation and inhibited apoptosis by regulating the NF-κB signal pathway via miR-149-3p in CSE-treated HBE cells. These results provide an insight for further verification and understanding of the molecular basis of COPD.

Antifibrotic and Regenerative Effects of Treamid in Pulmonary Fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive disease characterized by interstitial fibrosis and progressive respiratory failure. Pirfenidone and nintedanib slow down but do not stop the progression of IPF. Thus, new compounds with high antifibrotic activity and simultaneously regenerative activity are an unmet clinical need. Recently, we showed that Treamid can help restoring the pancreas and testicular tissue in mice with metabolic disorders. We hypothesized that Treamid may be effective in antifibrotic therapy and regeneration of damaged lung tissue in pulmonary fibrosis. In this study, experiments were performed on male C57BL/6 mice with bleomycin-induced pulmonary fibrosis. We applied histological and immunohistochemical methods, ELISA, and assessed the expression of markers of endothelial and epithelial cells in primary cultures of CD31+ and CD326+ lung cells. Finally, we evaluated esterase activity and apoptosis of lung cells in vitro. Our data indicate that Treamid exhibits antifibrotic activity in mice with pulmonary fibrosis and has a positive effect on capillaries of the lungs. Treamid also increases the number of endothelial progenitor cells in the lungs of animals with pulmonary fibrosis. Lastly, Treamid increases esterase activity and decreases apoptosis of CD31+ lung cells in vitro. Based on these findings, we suggest that Treamid may represent a promising compound for the development of new antifibrotic agents, which are capable of stimulating regeneration of lung endothelium in IPF patients.

Adipose mesenchymal stem cell-derived antioxidative extracellular vesicles exhibit anti-oxidative stress and immunomodulatory effects under PM2.5 exposure

PM2.5 exposure elevates the level of reactive oxygen species (ROS) in the lungs and leads to lung injury or other pulmonary conditions. Nrf2 is a key antioxidative regulator that suppresses ROS production. Extracellular vesicles (EVs) secreted by adipose mesenchymal stem cells (ADSCs) have been identified as therapeutic as well as potential drug/gene/protein carriers. In this study, we established rat (PM2.5, 100 μL, 5 mg/mL) or cell (PM2.5, 50 μg/mL) models to conduct in vivo and in vitro studies on the adverse pulmonary effects of PM2.5. Our findings indicated that the initial responses to PM2.5 exposure were robust oxidative stress and inflammation. EVs and antioxidative EVs (Antioxi-EVs, derived from ADSCs that overexpress Nrf2) had been tested as interventions in PM2.5-treated rat or cell models through tracheal instillation or co-incubation. Treatment with EVs or Antioxi-EVs (3 × 1010 particles in vivo and 1 × 109in vitro) was found to have a suppressive effect on the levels of ROS and inflammatory cytokines, with Antioxi-EVs having a superior effect on anti-oxidative stress. In particular, the occurrence of lung injury or cell apoptosis correlated positively with the ROS level, and inhibition of ROS by upregulating Nrf2 alleviated lung injury and cell apoptosis. Furthermore, treatment with EVs or Antioxi-EVs increased the level of M2-like macrophages as compared to treatment with PBS and further reduced IL-6 and TNF-α levels. Our results suggest that Antioxi-EVs can reduce the severity of oxidative stress, inflammation, and lung injury induced by PM2.5via anti-oxidative stress and immunomodulation pathways.

LncRNA ZEB1-AS1 is downregulated in diabetic lung and regulates lung cell apoptosis.

The present study aimed to investigate the role of ZEB1-antisense RNA 1 (AS1) in diabetic lung (pneumonia with excluded causes other than diabetes). In the present study, the expression of ZEB1-AS1 in plasma was detected by performing reverse transcription-quantitative PCR. A receiver operating characteristic curve was used for diagnostic analysis. Lung cell apoptosis under the treatment of high glucose was analyzed by a cell apoptosis assay. p53 expression in lung cells was detected by performing western blotting. The present data demonstrated that ZEB1-AS1 was downregulated in the plasma of patients with diabetic lung (DL) compared with diabetic patients without complications (~1.6-fold) and healthy controls (~2.4-fold), and downregulation of ZEB1-AS1 distinguished patients with DL from healthy controls. ZEB1-AS1 in lung cells was downregulated by high glucose treatment, and overexpression of ZEB1-AS1 resulted in inhibited lung cancer cell apoptosis and downregulated p53. p53 overexpression attenuated the effects of ZEB1-AS1 overexpression on lung cell apoptosis. In conclusion, the present study demonstrated that ZEB1-AS1 was downregulated in patients with DL and regulates lung cancer cell apoptosis by downregulating p53.

Thal protects against paraquat-induced lung injury through a microRNA-141/HDAC6/IκBα-NF-κB axis in rat and cell models.

The protective functions of thalidomide in paraquat (PQ)‐induced injury have been reported. But the mechanisms remain largely unknown. In this research, a PQ‐treated rat model was established and further treated with thalidomide. Oedema and pathological changes, oxidative stress, inflammation, fibrosis and cell apoptosis in rat lungs were detected. A PQ‐treated RLE‐6TN cell model was constructed, and the viability and apoptosis rate of cells were measured. Differentially expressed microRNAs (miRNAs) after thalidomide administration were screened out. Binding relationship between miR‐141 and histone deacetylase 6 (HDAC6) was validated. Altered expression of miR‐141 and HDAC6 was introduced to identify their involvements in thalidomide‐mediated events. Consequently, thalidomide administration alone exerted no damage to rat lungs; in addition it reduced PQ‐induced oedema. The oxidative stress, inflammation and cell apoptosis in rat lungs were reduced by thalidomide. In RLE‐6TN cells, thalidomide increased cell viability and decreased apoptosis. miR‐141 was responsible for thalidomide‐mediated protective events by targeting HDAC6. Overexpression of HDAC6 blocked the protection of thalidomide against PQ‐induced injury via activating the IkBα‐NF‐κB signalling pathway. Collectively, this study evidenced that thalidomide protects lung tissues from PQ‐induced injury through a miR‐141/HDAC6/IkBα‐NF‐κB axis.

Gut-lymph-lung pathway mediates sepsis-induced acute lung injury.

This review attempts to unveil the possible mechanisms underlying how gut lymph affects lung and further gives rise to acute respiratory distress syndrome, as well as potential interventional targets under the condition of ischemia-reperfusion injury. We searched electronic databases including PubMed, MEDLINE, Cochrane Central Register of Controlled Trials, Google Scholar, Web of Science, and Embase to identify relevant literatures published up to December 2019. We enrolled the literatures including the Mesh Terms of “gut lymph or intestinal lymph and acute lung injury or acute respiratory distress syndrome.” Gut is considered to be the origin of systemic inflammation and the engine of multiple organ distress syndrome in the field of critical care medicine, whereas gut lymph plays a pivotal role in initiation of ischemia-reperfusion injury-induced acute respiratory distress syndrome. In fact, in the having been established pathologic model of sepsis leading to multiple organ dysfunction named by Gut Lymph theory, a variety of literatures showed the position and role of changes in gut lymph components in the initiation of systemic inflammatory response, which allows us to screen out potential intervention targets to pave the way for future clinic and basic research.

LncRNA THRIL is upregulated in sepsis and sponges miR-19a to upregulate TNF-\u03b1 in human bronchial epithelial cells

BackgroundLong non-coding RNAs (lncRNAs) have been demonstrated to play critical roles in various diseases. Our bioinformatics analysis showed that lncRNA TNFα and heterogenous nuclear ribonucleoprotein L (hnRNPL) related immunoregulatory LincRNA (THRIL) may interact with miR-19a, which targets TNF-α. This study aimed to explore the role of THRIL, an enhancer of LPS-induced inflammatory, in sepsis.MethodsResearch subjects of the present study included 66 sepsis patients and 66 healthy volunteers. The expression levels of THRIL, miR-19a and TNF-α in plasma samples from these participants were determined by RT-qPCR. The interaction between THRIL and miR-19a was explored by performing overexpression experiments in human bronchial epithelial cells (HBEpCs). The roles of THRIL, miR-19a and TNF-α in regulating the apoptosis of HBEpCs were analyzed by cell apoptosis assay.ResultsWe found that THRIL was upregulated in sepsis patients. THRIL is predicted to interact with miR-19a, and the interaction was confirmed by dual-luciferase activity assay. However, THRIL and miR-19a did not affect the expression of each other. Instead, overexpression of THRIL resulted in the increased expression levels of TNF-α, a downstream target of miR-19a in HBEpCs. In HBEpCs, LPS treatment induced the overexpression of THRIL. Cell apoptosis analysis showed that overexpression of THRIL and TNF-α promoted the apoptosis of HBEpCs induced by LPS, while overexpression of miR-19a played an opposite role. Overexpression of THRIL attenuated the effects of overexpression of miR-19a.ConclusionTherefore, THRIL is upregulated in sepsis and may sponge miR-19a to upregulate TNF-α, thereby promoting lung cell apoptosis.

Ag NPs on chitosan-alginate coated magnetite for synthesis of indazolo[2,1-b]phthalazines and human lung protective effects against α-Guttiferin

Biocomposite nanomaterials have been evolved as the new generation catalysts and therapeutic supplement in these days. Magnetically isolation has added new features to this category. This has encouraged us to synthesize a novel Ag NP adorned chitosan-alginate dual bio-polysaccharide (two of the more versatile polysaccharides) modified core-shell magnetic nanocomposite (Fe3O4/CS-Alg/Ag NPs). The material was meticulously characterized following different physicochemical techniques, such as, FT-IR, ICP-OES, FESEM, EDX, atomic mapping, TEM, VSM, XRD and XPS studies. The as synthesized material was catalytically explored in the one-pot multicomponent synthesis of biologically potent 2H-indazolo[2,1-b]phthalazine-trione derivatives involving a wide range of substrates. The reactions were ended up with excellent yields under solvent-free heating conditions. The catalyst recyclability, heterogeneity and leaching tests were performed to ensure its high stability and robustness. It could be reused as much as 10 times in succession with almost unchanged catalytic performances. In the lung protective part of the present research, the human lung toxicity was induced by α-Guttiferin. The cell viability of lung MRC-5, CCD19Lu, WI-38, and BEAS-2B cell lines was measured by trypan blue assay. Caspase-3 activity was assessed by the caspase activity colorimetric assay kit and mitochondrial membrane potential of lung cells was studied by Rhodamine123 fluorescence dye. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) test was used to show DNA fragmentation and apoptosis of lung cells. Also, the Rat inflammatory cytokine assay kit was used to measure the concentrations of inflammatory cytokines. The catalyst-treated cell cutlers significantly (p ≤ 0.01) reduced the DNA fragmentation, caspase-3 activity, and inflammatory cytokines concentrations, and raised the mitochondrial membrane potential and cell viability in the high concentration of α-Guttiferin-treated lung MRC-5, CCD19Lu, WI-38, and BEAS-2B cells. The best result of lung protective properties of catalyst against α-Guttiferin was seen in the high dose of catalyst i.e., 4 μg. DPPH test revealed similar antioxidant potentials for catalyst and butylated hydroxytoluene. The catalyst inhibited half of the DPPH molecules in the concentration of 171 μg/mL. According to the above results, catalyst can be administrated as a lung protective drug for the treatment of lung diseases after approving in the clinical trial studies in humans.

Magnesium lithospermate B ameliorates hypobaric hypoxia-induced pulmonary arterial hypertension by inhibiting endothelial-to-mesenchymal transition and its potential targets

Pulmonary arterial hypertension (PAH) is a progressive disease characterized by vascular remodeling leading to elevation of pulmonary artery pressure, right ventricular hypertrophy, and death. Currently, there are no cure exists for PAH. Magnesium lithospermate B (MLB) is the major component of Salvia przewalskii water extracts with treating angina and cardiovascular damage, anti-inflammation, anti-oxidation and anti-apoptosis. However, the effects of MLB on PAH still unclear. This study we investigated the efficacy of MLB in the hypobaric hypoxia-induced rat model of PAH. The results showed that MLB relieved mean pulmonary arterial pressure (mPAP) and right ventricular hypertrophy index (RVHI). Meanwhile, MLB significantly reduced pulmonary vascular remodeling. Additionally, MLB inhibited hypobaric hypoxia-induced α-smooth muscle actin (α-SMA) expression, cell apoptosis, and α-SMA and von Willebrand factor (vWF) co-expression in lung, suggesting that MLB could inhibit hypobaric hypoxia-induced endothelial-to-mesenchymal transition (EndMT). Furthermore, after treatment with MLB, the expression of hypoxia inducible factor-1α (HIF-1α), nuclear factor-kappa B (NF-κB), monocyte chemoattractant protein-1 (MCP-1), proliferating cell nuclear antigen (PCNA), cyclin-dependent kinase 4 (CDK4), CyclinD1, RhoA, rho-associated protein kinase 1 (ROCK1) and ROCK2 was decreased. Further, CHK1, PIM1, STK6, LKHA4, PDE5A, BRAF1, PLK1, AKT1, PAK6, PAK7 and ELNE may be the potential targets of MLB. Taken together, our findings suggest that MLB ameliorates hypobaric hypoxia-induced PAH by inhibiting EndMT in rats, and has potential value in the preventment and treatment of PAH.

Dexmedetomidine alleviates LPS‑induced acute lung injury via regulation of the p38/HO‑1 pathway.

Acute lung injury (ALI) is a common critical illness in clinical anesthesia and the intensive care unit that can cause acute hypoxic respiratory insufficiency. Despite various therapeutic regimes having been investigated, there is currently no effective pharmacotherapy available to treat ALI. Previous studies have reported that the NOD-like receptor protein 3 (NLRP3) signaling pathway plays an important role in the inflammatory response and is involved in the pathogenesis of ALI. Moreover, dexmedetomidine (Dex), an α2-adrenergic receptor activating agent, has been routinely used as an adjuvant therapy in treating inflammatory diseases, including ALI. However, the precise pathological mechanisms of Dex in ALI remain to be elucidated. Thus, the present study aimed to investigate the effects of the p38/heme oxygenase 1 (HO-1) signaling pathways in the pathological mechanisms of Dex in ALI. Newborn male Sprague-Dawley rats (n=48) were randomly divided into four groups (n=12 each), and an intravenous injection of lipopolysaccharide (LPS) was used to successfully induce the ALI model, with increased pulmonary damage, cell apoptosis, interleukin-1β (IL-1β) secretion and edema fluid in lungs. Moreover, the mRNA and protein expression levels of NLRP3 were significantly upregulated, while that of HO-1 were downregulated by LPS treatment. Furthermore, the levels of phosphorylated p38 were also upregulated in ALI rats. It was demonstrated that Dex administration significantly alleviated LPS-induced ALI, downregulated the secretion of IL-1β, decreased the expression of NLRP3, inhibited the phospho-activation of p38 and increased HO-1 expression. In addition, pharmacological inhibition of p38 using the inhibitor SB20380 further enhanced the effect of Dex. Collectively, these preliminarily results identified the effects of Dex intervention on the pathogenesis of ALI via the regulation of p38/HO-1 signaling pathways, which impacted the inflammatory effects, thus providing a theoretical basis and novel evidence for the development of new targets for clinical treatment of ALI.

Apoptosis of lung cells regulated by mitochondrial signal pathway in crotonaldehyde-induced lung injury.

Crotonaldehyde, a highly toxic α, β-unsaturated aldehyde, is a ubiquitous hazardous pollutant. Because of its extreme toxicity and ubiquity in all types of smoke, most current research focuses on the lung toxicity of such air pollutants. However, the specific mechanism of pulmonary toxicity caused by crotonaldehyde remains unclear, especially after long-term exposure to crotonaldehyde at low dose. Therefore, the aim of the present study is to determine whether crotonaldehyde-induced oxidative damage and inflammation promote apoptosis in rats via the mitochondrial pathway using histopathology, immunohistochemistry, biochemistry analysis and Western blot analysis. The results show that crotonaldehyde elicited oxidative damage and inflammation in rats in a concentration-dependent manner. Crotonaldehyde-induced lung injury which was confirmed by H&E, Masson's trichrome staining and TUNEL. And crotonaldehyde-induced lung cell apoptosis showed a concentration-response relationship. Immunohistochemistry and Western blot results showed that apoptotic mitochondrial signaling pathway is abnormally activated in crotonaldehyde-induced lung injury. Collectively, this study demonstrates that exposure of rats to crotonaldehyde induces lung injury by inducing apoptosis, which is related to oxidative damage and inflammation through mitochondrial pathway.

Enhanced Notch3 signaling contributes to pulmonary emphysema in a Murine Model of Marfan syndrome

Marfan syndrome (MFS) is a heritable disorder of connective tissue, caused by mutations in the fibrillin-1 gene. Pulmonary functional abnormalities, such as emphysema and restrictive lung diseases, are frequently observed in patients with MFS. However, the pathogenesis and molecular mechanism of pulmonary involvement in MFS patients are underexplored. Notch signaling is essential for lung development and the airway epithelium regeneration and repair. Therefore, we investigated whether Notch3 signaling plays a role in pulmonary emphysema in MFS. By using a murine model of MFS, fibrillin-1 hypomorphic mgR mice, we found pulmonary emphysematous-appearing alveolar patterns in the lungs of mgR mice. The septation in terminal alveoli of lungs in mgR mice was reduced compared to wild type controls in the early lung development. These changes were associated with increased Notch3 activation. To confirm that the increased Notch3 signaling in mgR mice was responsible for structure alterations in the lungs, mice were treated with N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglucine t-butyl ester (DAPT), a gamma-secretase inhibitor, which inhibits Notch signaling. DAPT treatment reduced lung cell apoptosis and attenuated pulmonary alteration in mice with MFS. This study indicates that Notch3 signaling contributes to pulmonary emphysema in mgR mice. Our results may have the potential to lead to novel strategies to prevent and treat pulmonary manifestations in patients with MFS.

Hydrogen Sulfide Ameliorates Lung Ischemia-Reperfusion Injury Through SIRT1 Signaling Pathway in Type 2 Diabetic Rats.

Lung ischemia-reperfusion (IR) injury remains a significant factor for the early mortality of lung transplantations. Diabetes mellitus (DM) is an independent risk factor for 5-year mortality following lung transplantation. Our previous study showed that DM aggravated lung IR injury and that oxidative stress played a key role in this process. Previously, we demonstrated that hydrogen sulfide (H2S) protected against diabetic lung IR injury by suppressing oxidative damage. This study aimed to examine the mechanism by which H2S affects diabetic lung IR injury. High-fat-diet-fed streptozotocin-induced type 2 diabetic rats were exposed to GYY4137, a slow-releasing H2S donor with or without administration of EX527 (a SIRT1 inhibitor), and then subjected to a surgical model of IR injury of the lung. Lung function, oxidative stress, cell apoptosis, and inflammation were assessed. We found that impairment of lung SIRT1 signaling under type 2 diabetic conditions was further exacerbated by IR injury. GYY4137 treatment markedly activated SIRT1 signaling and ameliorated lung IR injury in type 2 DM animals by improving lung functional recovery, diminishing oxidative damage, reducing inflammation, and suppressing cell apoptosis. However, these effects were largely compromised by EX527. Additionally, treatment with GYY4137 significantly activated the Nrf2/HO-1 antioxidant signaling pathway and increased eNOS phosphorylation. However, these effects were largely abolished by EX527. Together, our results indicate that GYY4137 treatment effectively attenuated lung IR injury under type 2 diabetic conditions via activation of lung SIRT1 signaling. SIRT1 activation upregulated Nrf2/HO-1 and activated the eNOS-mediated antioxidant signaling pathway, thus reducing cell apoptosis and inflammation and eventually preserving lung function.

Molecular dynamics exploring of atmosphere components interacting with lung surfactant phospholipid bilayers

Sulfur dioxide (SO2), nitrogen oxide (NO2) and ozone (O3) in the atmosphere are significantly correlated with various respiratory and cardiovascular diseases. High doses of each of these gases or a mixture can change the physical and chemical properties of the lung membrane, thus leading to an increased pulmonary vascular permeability and structural failure of the alveolar cell membrane. In the present study, detailed molecular dynamic (MD) modeling was applied to investigate the effects of SO2, NO2, O3 and mixtures of these gases on the dipalmitoyl phosphatidylcholine (DPPC) phospholipid bilayer. The results showed that several key physical properties, including the mass density, lipid ordering parameter, lipid diffusion, and electrostatic potential of the cell membrane, have been changed by the binding of different compounds. This resulted in significant variations and more disorder in the DPPC bilayer. The multiple analyses of membrane properties proved the toxicity of NO2, O3, and SO2 to the DPPC bilayer, providing a theoretical basis for the experimental phenomenon that SO2, NO2 and O3 can cause lung cell apoptosis. For the single systems, the damage to DPPC bilayer caused by O3 was more serious than NO2 and SO2. More importantly, the MD simulations using the mixtures of SO2, NO2, and O3 showed a much greater decline of membrane fluidity and the aggravation of membrane damage than the single systems, indicating a synergistic effect when NO2, SO2, and O3 coexisted in the atmosphere, which could lead to much more severe damage and greater toxicities to the lung.

Topiroxostat ameliorates oxidative stress and inflammation in sepsis-induced lung injury.

Sepsis-induced lung injury was the most common cause of death in patients. Topiroxostat, a novel xanthine oxidoreductase inhibitors, possessed obvious organ protectives effects. Xanthine oxidase played a vital role in acute lung injury. The study aimed to investigate the roles of Topiroxostat in sepsis-induced lung injury. The sepsis rats were established using cecum ligation and perforation. The lung damage induced by sepsis was evaluated by Hematoxylin and Eosin staining and lung tissue wet to dry ratio. The oxidative stress was detected by measurement of reactive oxygen species, malondialdehyde, myeloperoxidase and superoxide dismutase (SOD). The pro-inflammatory mediators, tumor necrosis factor-α, interleukin (IL)-1β, IL-6 and monocyte chemotactic protein 1, were measured by Enzyme-Linked Immunosorbent Assay. The cell apoptosis in lung was detected by TUNNEL staining and western blot analysis of apoptosis-related proteins including pro-apoptosis proteins, Bax, cleaved caspase9, cleaved caspase3 and anti-apoptosis protein Bcl2. The results showed that Topiroxostat significantly reduced lung damage, along with decreased oxidative stress, inflammation response and apoptosis in sepsis rats. Topiroxostat exerted markedly protective effects in sepsis-induced lung injury and could be an antioxidant in treating sepsis-induced lung injury.

Let-7b-5p is involved in the response of endoplasmic reticulum stress in acute pulmonary embolism through upregulating the expression of stress-associated endoplasmic reticulum protein 1.

The endogenous non-coding microRNA (miRNA) let-7b-5p is highly expressed in the blood of patients with acute pulmonary embolism (PE). However, the mechanism underlying the involvement of let-7b-5p in acute PE remains unclear. To address this, we investigated the role of let-7b-5p in acute PE in both in vitro and in vivo experimental models. The results showed that let-7b-5p upregulated the expression of stress-associated endoplasmic reticulum protein 1 (SERP1) at the post-transcriptional level. SERP1 activation leads to modulation of its chaperone protein SEC61B in the response of endoplasmic reticulum (ER) stress. Furthermore, our data show that the unfolded protein response was triggered and activation of unfolded proteins GRP78, PERK, RNF121, and CHOP occurred through the PERK-CHOP pathway, resulting in an inflammatory response and apoptosis of lung epithelial cells. These characteristics were promoted by the in vitro expression of a let-7b-5p mimic; conversely, transfection with a let-7b-5p inhibitor decreased the response of ER stress in acute PE. The results from this study thus provide evidence that let-7b-5p promotes protein processing during ER stress response by upregulating SERP1 expression, ultimately resulting in an inflammatory response and apoptosis of lung cells, cumulatively playing a critical role in the pathogenesis of acute PE.

Adiponectin ameliorates lung injury induced by intermittent hypoxia through inhibition of ROS-associated pulmonary cell apoptosis.

Obstructive sleep apnea hypopnea syndrome has been reported to be associated with pulmonary hypertension (PH). Adiponectin (Ad) has many protective roles in the human body, including its function as an anti-inflammatory and an anti-oxidant, as well as its role in preventing insulin resistance and atherosclerosis. This study aimed to investigate the molecular mechanism of chronic intermittent hypoxia (CIH)-induced pulmonary injury and the protective role of Ad in experimental rats. Thirty male Sprague-Dawley rats were randomly divided into three groups with 10 rats in each group: normal control (NC) group, CIH group, and CIH + Ad group. Rats in the NC group were kept breathing room air for 12weeks. Rats in the CIH group were intermittently exposed to a hypoxic environment for 8h/day for 12weeks. Rats in the CIH + Ad group received 10μg Ad twice weekly via intravenous injection. After 12weeks of CIH exposure, we detected the pulmonary function, pulmonary artery pressure, lung histology, pulmonary cell apoptosis, pulmonary artery endothelial cell apoptosis, mitochondrial membrane potential (MMP), and reactive oxygen species (ROS) level. We also analyzed expression proteins involved in the mitochondria-, endoplasmic reticulum (ER) stress-, and Fas receptor-associated pulmonary apoptosis pathways, as well as the SIRT3/SOD2 pathway. CIH exposure for 12weeks did not lead to abnormal pulmonary function, PH, or pulmonary artery endothelial cell apoptosis. However, we observed a significant increase in the rate of pulmonary cell apoptosis, the expression of proteins involved in mitochondria-, ER stress-, and Fas receptor-associated pulmonary apoptosis pathways, and the generation of ROS in the CIH group compared with the NC group. In contrast, the MMP and protein expressions of SIRT3/SOD2 pathway were significantly decreased in the CIH group compared with the NC group. Ad supplementation in the CIH + Ad group partially improved these changes induced by CIH. Even though CIH did not cause abnormal pulmonary function or PH, early lung injury was detected at the molecular level in rats exposed to CIH. Treatment with Ad ameliorated the pulmonary injury by activating the SIRT3/SOD2 pathway, reducing ROS generation, and inhibiting ROS-associated lung cell apoptosis.

Systems pharmacology reveals the mechanism of activity of Physalis alkekengi L. var. franchetii against lipopolysaccharide-induced acute lung injury.

Acute lung injury (ALI) is an important cause of mortality of patients with sepsis, shock, trauma, pneumonia, multiple transfusions and pancreatitis. Physalis alkekengi L. var. franchetii (Mast.) Makino (PAF) has been extensively used in Chinese folk medicine because of a good therapeutic effect in respiratory diseases. Here, an integrated approach combining network pharmacology, proton nuclear magnetic resonance‐based metabolomics, histopathological analysis and biochemical assays was used to elucidate the mechanism of PAF against ALI induced by lipopolysaccharide (LPS) in a mouse model. We found that the compounds present in PAF interact with 32 targets to effectively improve the damage in the lung undergoing ALI. We predicted the putative signalling pathway involved by using the network pharmacology and then used the orthogonal signal correction partial least‐squares discriminant analysis to analyse the disturbances in the serum metabolome in mouse. We also used ELISA, RT‐qPCR, Western blotting, immunohistochemistry and TUNEL assay to confirm the potential signalling pathways involved. We found that PAF reduced the release of cytokines, such as TNF‐α, and the accumulation of oxidation products; decreased the levels of NF‐κB, p‐p38, ERK, JNK, p53, caspase‐3 and COX‐2; and enhanced the translocation of Nrf2 from the cytoplasm to the nucleus. Collectively, PAF significantly reduced oxidative stress injury and inflammation, at the same time correcting the energy metabolism imbalance caused by ALI, increasing the amount of antioxidant‐related metabolites and reducing the apoptosis of lung cells. These observations suggest that PAF may be an effective candidate preparation alleviating ALI.