Therapeutic potential of ADSC-EV-derived lncRNA DLEU2: A novel molecular pathway in alleviating sepsis-induced lung injury via the miR-106a-5p/LXN axis.

This study investigates the molecular mechanisms by which extracellular vesicles (EVs) derived from adipose-derived mesenchymal stem cells (ADSCs) promote M2 polarization of macrophages and thus reduce lung injury caused by sepsis. High-throughput sequencing was used to identify differentially expressed genes related to long non-coding RNA (lncRNA) in ADSC-derived EVs (ADSC-EVs) in sepsis lung tissue. Weighted gene co-expression network analysis (WGCNA) was employed to predict the downstream target genes of the lncRNA DLEU2. The RNAInter database predicted miRNAs that interact with DLEU2 and LXN. Functional and pathway enrichment analyses were performed using GO and KEGG analysis. A mouse model of sepsis was established, and treatment with a placebo or ADSC-EVs was administered, followed by RT-qPCR analysis. ADSC-EVs were isolated and identified. In vitro cell experiments were conducted using the mouse lung epithelial cell line MLE-12, mouse macrophage cell line RAW264.7, and mouse lung epithelial cell line (LEPC). ADSC-EVs were co-cultured with RAW264.7 and MLE-12/LEPC cells to study the regulatory mechanism of the lncRNA DLEU2. Cell viability, proliferation, and apoptosis of lung injury cells were assessed using CCK-8, EdU, and flow cytometry. ELISA was used to measure the levels of inflammatory cytokines in the sepsis mouse model, flow cytometry was performed to determine the number of M1 and M2 macrophages, lung tissue pathology was evaluated by H&E staining, and immunohistochemistry was conducted to examine the expression of proliferation- and apoptosis-related proteins. High-throughput sequencing and bioinformatics analysis revealed enrichment of the lncRNA DLEU2 in ADSC-EVs in sepsis lung tissue. Animal and in vitro cell experiments showed increased expression of the lncRNA DLEU2 in sepsis lung tissue after treatment with ADSC-EVs. Furthermore, ADSC-EVs were found to transfer the lncRNA DLEU2 to macrophages, promoting M2 polarization, reducing inflammation response in lung injury cells, and enhancing their viability, proliferation, and apoptosis inhibition. Further functional experiments indicated that lncRNA DLEU2 promotes M2 polarization of macrophages by regulating miR-106a-5p/LXN, thereby enhancing the viability and proliferation of lung injury cells and inhibiting apoptosis. Overexpression of miR-106a-5p could reverse the biological effects of ADSC-EVs-DLEU2 on MLE-12 and LEPC in vitro cell models. Lastly, in vivo animal experiments confirmed that ADSC-EVs-DLEU2 promotes high expression of LXN by inhibiting the expression of miR-106a-5p, further facilitating M2 macrophage polarization and reducing lung edema, thus alleviating sepsis-induced lung injury. lncRNA DLEU2 in ADSC-EVs may promote M2 polarization of macrophages and enhance the viability and proliferation of lung injury cells while inhibiting inflammation and apoptosis reactions, thus ameliorating sepsis-induced lung injury in a mechanism involving the regulation of the miR-106a-5p/LXN axis.

Preclinical efficacy and clinical safety of clinical-grade nebulized allogenic adipose mesenchymal stromal cells-derived extracellular vesicles.

Mesenchymal stromal cell-derived extracellular vesicles (MSC-EVs) turn out to be a promising source of cell-free therapy. Here, we investigated the biodistribution and effect of nebulized human adipose-derived MSC-EVs (haMSC-EVs) in the preclinical lung injury model and explored the safety of nebulized haMSC-EVs in healthy volunteers. DiR-labelled haMSC-EVs were used to explore the distribution of nebulized haMSC-EVs in the murine model. Pseudomonas aeruginosa-induced murine lung injury model was established, and survival rate, as well as WBC counts, histology, IL-6, TNF-α and IL-10 levels in bronchoalveolar lavage fluid (BALF) were measured to explore the optimal therapeutic dose of haMSC-EVs through the nebulized route. Twenty-four healthy volunteers were involved and received the haMSC-EVs once, ranging from 2 × 108 particles to 16 × 108 particles (MEXVT study, NCT04313647). Nebulizing haMSC-EVs improved survival rate to 80% at 96 h in P. aeruginosa-induced murine lung injury model by decreasing lung inflammation and histological severity. All volunteers tolerated the haMSC-EVs nebulization well, and no serious adverse events were observed from starting nebulization to the 7th day after nebulization. These findings suggest that nebulized haMSC-EVs could be a promising therapeutic strategy, offering preliminary evidence to promote the future clinical applications of nebulized haMSC-EVs in lung injury diseases.

Acinetobacter baumannii up-regulates LncRNA-GAS5 and promotes the degradation of STX17 by blocking the activation of YY1.

Acinetobacter baumanniitriggers autophagy, affects the degradation of autophagy, and causes severe inflammatory injury. LncRNA growth arrest-specific transcript 5 (LncRNA-GAS5) and Yin and Yang 1 (YY1) are known to play an important role in the regulation of autophagy, however, the precise role of LncRNA-GAS5 and YY1 in the damage to autophagy caused by Acinetobacter baumanniiremains unclear. The aim of this study was to investigate the role of LncRNA-GAS5 and YY1 in the regulation of autophagy induced by Acinetobacter baumannii. We found that LncRNA-GAS5 was up-regulated following infection with Acinetobacter baumannii, thus resulting in the degradation of STX17, autophagy disorders, and the aggravated replication of Acinetobacter baumannii. We also analyzed the mechanism of interaction between LncRNA-GAS5 and YY1 and found that YY1 regulated its expression in a negative manner by binding to the promoter of LncRNA-GAS5. LncRNA-GAS5 and YY1 had opposite effects on the expression of STX17, this process maintained the stable expression of STX17. Following Acinetobacter baumannii infection, YY1 was down regulated and then separated from the binding region of LncRNA-GAS5, thus resulting in the activation of LncRNA-GAS5 transcription and reduction in STX17 protein expression. Finally, we infected LncRNA-GAS5 knockdown mice with Acinetobacter baumannii, the expression levels of IFN-ß in the lungs increased significantly, this alleviated lung injury. In conclusion, our work demonstrated the mechanism by which Acinetobacter baumannii infection can cause the degradation of STX17. We also demonstrated that LncRNA-GAS5 may be a potential therapeutic target for the treatment of lung injury induced by Acinetobacter baumannii.

Amniotic fluid interleukin 6 and interleukin 8 are superior predictors of fetal lung injury compared with maternal or fetal plasma cytokines or placental histopathology in a nonhuman primate model.

BACKGROUND: Intra-amniotic infection or inflammation is common in early preterm birth and associated with substantial neonatal lung morbidity owing to fetal exposure to proinflammatory cytokines and infectious organisms. Amniotic fluid interleukin 8, a proinflammatory cytokine, was previously correlated with the development of neonatal bronchopulmonary dysplasia, but whether amniotic fluid cytokines or placental pathology more accurately predicts neonatal lung pathology and morbidity is unknown. We have used a pregnant nonhuman primate model of group B Streptococcus infection to study the pathogenesis of intra-amniotic infection, bacterial invasion of the amniotic cavity and fetus, and microbial-host interactions. In this nonhuman primate model, we have studied the pathogenesis of group B Streptococcus strains with differing potential for virulence, which has resulted in a spectrum of intra-amniotic infection and fetal lung injury that affords the opportunity to study the inflammatory predictors of fetal lung pathology and injury. OBJECTIVE: This study aimed to determine whether fetal lung injury is best predicted by placental histopathology or the cytokine response in amniotic fluid or maternal plasma. STUDY DESIGN: Chronically catheterized pregnant monkeys (Macaca nemestrina, pigtail macaque) at 116 to 125 days gestation (term at 172 days) received a choriodecidual inoculation of saline (n=5), weakly hemolytic group B Streptococcus strain (n=5, low virulence), or hyperhemolytic group B Streptococcus strain (n=5, high virulence). Adverse pregnancy outcomes were defined as either preterm labor, microbial invasion of the amniotic cavity, or development of the fetal inflammatory response syndrome. Amniotic fluid and maternal and fetal plasma samples were collected after inoculation, and proinflammatory cytokines (tumor necrosis factor alpha, interleukin beta, interleukin 6, interleukin 8) were measured by a multiplex assay. Cesarean delivery was performed at the time of preterm labor or within 1 week of inoculation. Fetal necropsy was performed at the time of delivery. Placental pathology was scored in a blinded fashion by a pediatric pathologist, and fetal lung injury was determined by a semiquantitative score from histopathology evaluating inflammatory infiltrate, necrosis, tissue thickening, or collapse scored by a veterinary pathologist. RESULTS: The principal findings in our study are as follows: (1) adverse pregnancy outcomes occurred more frequently in animals receiving hyperhemolytic group B Streptococcus (80% with preterm labor, 80% with fetal inflammatory response syndrome) than in animals receiving weakly hemolytic group B Streptococcus (40% with preterm labor, 20% with fetal inflammatory response syndrome) and in controls (0% preterm labor, 0% fetal inflammatory response syndrome); (2) despite differences in the rate of adverse pregnancy outcomes and fetal inflammatory response syndrome, fetal lung injury scores were similar between animals receiving the weakly hemolytic group B Streptococcus strains and animals receiving the hyperhemolytic group B Streptococcus strains; (3) fetal lung injury score was significantly correlated with peak amniotic fluid cytokines interleukin 6 and interleukin 8 but not tumor necrosis factor alpha or interleukin 1 beta; and (4) fetal lung scores were poorly correlated with maternal and fetal plasma cytokine levels and placental pathology. CONCLUSION: Amniotic fluid interleukin 6 and interleukin 8 levels were superior predictors of fetal lung injury than placental histopathology or maternal plasma cytokines. This evidence supports a role for amniocentesis in the prediction of neonatal lung morbidity owing to intra-amniotic infection, which cannot be provided by cytokine analysis of maternal plasma or placental histopathology.

Tea polyphenols and Levofloxacin alleviate the lung injury of hepatopulmonary syndrome in common bile duct ligation rats through Endotoxin -TNF signaling.

BACKGROUND & AIMS: Hepatopulmonary syndrome (HPS) is characterized by pulmonary vasodilation and arterial blood oxygen desaturation in patients with chronic liver disease. Generally, common bile duct ligation (CBDL) rats are a suitable experimental model for studying hepatopulmonary syndrome. Our previous study demonstrated that endotoxin surges markedly, followed by bacterial translocation and the loss of liver immune function in all the stages of CBDL, thereby contributing to the pathogenesis of HPS. However, the mechanisms behind the increase of the endotoxin and how to alleviate it have not yet been elucidated. Pulmonary injury induced by increased bilirubin, endotoxin, and inflammatory mediators occurs in the early and later stages of CBDL. This study assessed the effects of Tea polyphenols (TP) and Levofloxacin on endotoxin reduction and suppression of lung injury in HPS rats in the long and short term, respectively. METHODS: Morphological change of pulmonary injury, HPS relative index, endotoxin concentration, and the activation extent of Malondialdehyde (MDA) and Myeloperoxidase (MPO) were evaluated in CBDL rats with or without TP and Levofloxacin for three weeks or six weeks. The inflammation factors of serum, lung tissue, and BALF were then compared at the same condition for the two time periods. This was followed by adoption of the network pharmacology approach, which was mainly composed of active component gathering, target prediction, HPS gene collection, network analysis, and gene enrichment analysis. Finally, the mRNA and protein levels of the inflammatory factors were studied and relative signaling expression was assessed using RT-PCR and Western blot analysis. RESULTS: The obtained results indicated that the pulmonary injury manifestation was perceived and endotoxin, MDA, and MPO activation were markedly increased in the early and later stages of CBDL. TP and Levofloxacin treatment alleviated endotoxin infection and inflammation factor expression three weeks and six weeks after CBDL. In addition, Levofloxacin displayed a short time anti-bacterial effect, while TP exerted a long period function. TP and Levofloxacin also reduced TNF-α, TGF-ß, IL-1ß, PDGF-BB, NO, ICAM-1, and ET-1 expression on the mRNA or protein expression. With regard to the pharmacological mechanism, the network analysis indicated that 12 targets might be the therapeutic targets of TP and Levofloxacin on HPS, namely ET-1, NOs3, VEGFa, CCl2, TNF, Ptgs2, Hmox1, Alb, Ace, Cav1, and Mmp9. The gene enrichment analysis implied that TP and Levofloxacin probably benefited patients with HPS by modulating pathways associated with the AGE-RAGE signaling pathway, the TNF signaling pathway, the HIF-1 signaling pathway, the VEGF signaling pathway, and the IL-17 signaling pathway, Rheumatoid arthritis, Fluid shear stress, and atherosclerosis. Finally, the TNF-α level was mainly diminished on the protein level following CBDL. CONCLUSIONS: TP and Levofloxacin could alleviate pulmonary injury for short and long period, respectively, while at the same time preventing endotoxin and the development of HPS in CBDL rats. These effects are possibly associated with the regulation of the Endotoxin -TNF-α pathways.

SOCS3-microtubule interaction via CLIP-170 and CLASP2 is critical for modulation of endothelial inflammation and lung injury.

Proinflammatory cytokines such as IL-6 induce endothelial cell (EC) barrier disruption and trigger an inflammatory response in part by activating the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway. The protein suppressor of cytokine signaling-3 (SOCS3) is a negative regulator of JAK-STAT, but its role in modulation of lung EC barrier dysfunction caused by bacterial pathogens has not been investigated. Using human lung ECs and EC-specific SOCS3 knockout mice, we tested the hypothesis that SOCS3 confers microtubule (MT)-mediated protection against endothelial dysfunction. SOCS3 knockdown in cultured ECs or EC-specific SOCS3 knockout in mice resulted in exacerbated lung injury characterized by increased permeability and inflammation in response to IL-6 or heat-killed Staphylococcus aureus (HKSA). Ectopic expression of SOCS3 attenuated HKSA-induced EC dysfunction, and this effect required assembled MTs. SOCS3 was enriched in the MT fractions, and treatment with HKSA disrupted SOCS3-MT association. We discovered that-in addition to its known partners gp130 and JAK2-SOCS3 interacts with MT plus-end binding proteins CLIP-170 and CLASP2 via its N-terminal domain. The resulting SOCS3-CLIP-170/CLASP2 complex was essential for maximal SOCS3 anti-inflammatory effects. Both IL-6 and HKSA promoted MT disassembly and disrupted SOCS3 interaction with CLIP-170 and CLASP2. Moreover, knockdown of CLIP-170 or CLASP2 impaired SOCS3-JAK2 interaction and abolished the anti-inflammatory effects of SOCS3. Together, these findings demonstrate for the first time an interaction between SOCS3 and CLIP-170/CLASP2 and reveal that this interaction is essential to the protective effects of SOCS3 in lung endothelium.

Gut microbiota modulation and anti-inflammatory properties of Xuanbai Chengqi decoction in septic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Xuanbai Chengqi decoction (XBCQ), a traditional Chinese medicine formulation, was reported to have a protective role in a variety of pulmonary infection diseases. However, its mechanism remains uncertain. In the current study, we investigated the potential mechanism of XBCQ, its therapeutic effects on organ injuries induced by sepsis and gut microbiota modulation. MATERIAL AND METHODS: 80 Male Sprague Dawley rats were performed cecal ligation and puncture (CLP) for sepsis model and 60 of them were treated with different doses of XBCQ (3.78, 7.56, 15.12 g/Kg, 20 rats per group) twice per day. After the most valid dose was determined, another 40 rats were divided randomly into four groups: sham group, sham + XBCQ group, sepsis group, sepsis + XBCQ group. The sepsis + XBCQ group was treated with XBCQ by intragastric administration and then twice per day. Feces of the rats were collected and the gut microbiota constituents were analyzed by 16S rDNA sequencing. Histological changes were observed by H&E staining. Occludin content in the colon was determined by immunohistochemical analysis. The concentrations of cytokines were determined by enzyme-linked immunosorbent assay (ELISA) kits. RESULTS: The survival rate of septic rats was increased significantly at the dose of 7.56 g/Kg from 50% to 80% at 72 h. The gut microbiota richness and composition were disturbed in septic rats. XBCQ altered the gut microbiota, involving alpha diversity changes, significantly reducing the relative abundance of Bacteroidaceae and ClostridiumXI and increasing that of Firmicutes and Actinobacteria. Furthermore, the relative abundances of Lactobacillus, Butyricicoccus and Bifidobacterium were increased by XBCQ. Moreover, the gut barrier dysfunction was improved by XBCQ through restoring the impaired tight conjunction protein Occludin. The concentration of diamine oxidase was decreased, while the D-lactate level was elevated. Meanwhile, the level of myeloperoxidase (MPO) in the lung tissue of the XBCQ-treated group was reduced. Lung injury was also alleviated by decreased levels of tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1ß) and interleukin 10 (IL-10) in bronchoalveolar lavage fluids (BALFs). The relative abundance of potential microbial biomarkers in four groups significantly correlated with the concentration of inflammatory factors in BALFs. CONCLUSIONS: Our results suggested that XBCQ had a protective role against sepsis by modulating the gut microbiota, restoring the intestinal epithelial barrier and decreasing inflammatory responses.

Autophagy suppression plays a role in parenteral nutrition-associated lung injury.

BACKGROUND & AIMS: The long-term usage of parenteral nutrition (PN) is associated with the increased incidence of pneumonia. Few studies have focused on the pathogenesis of PN-associated lung injury (PNLI). Previous studies have found that autophagy suppression may be an important mechanism for PN-associated complications. The present study aimed to investigate the effect of PN on lung barrier impairment and its association with autophagy. METHODS: We retrospectively identified intestinal failure patients admitted to a clinical nutrition service center to determine the morbidity of hospital-acquired pneumonia (HAP) and its association with PN. In animal studies, we established the PNLI mouse model to measure severity of lung injury, lung barrier, pulmonary microbiota in bronchoalveolar fluid (BALF), levels of autophagy and apoptosis, and the inflammatory signaling pathway. RESULT: Among the 259 patients, 37 (14.3%) patients developed HAP. Multivariate analysis revealed that prolonged PN was an independent predictor for HAP. In animal studies, we found that PN impaired the lung barrier and disturbed pulmonary microbiota homeostasis. The abundance of Actinomycetes and Firmicutes phyla in BALF were significantly increased, while the Bacteroidetes phylum decreased. Bacterial translocations in the lung were observed by fluorescence in situ hybridization. PN caused autophagy suppression and activated the apoptosis level and inflammatory HMGB1/RAGE/NF-kB signaling pathway. The intervention of exogenous rapamycin can attenuate the impairment of the lung barrier, reduce apoptosis and inhibit inflammatory signaling by upregulation of autophagy. CONCLUSION: PN had a damaging effect on the lung barrier, disturbed pulmonary microbiota homeostasis, and induced bacterial translocation. Autophagy suppression might be a crucial mechanism in inducing PNLI.

Vascular surveillance by haptotactic blood platelets in inflammation and infection.

Breakdown of vascular barriers is a major complication of inflammatory diseases. Anucleate platelets form blood-clots during thrombosis, but also play a crucial role in inflammation. While spatio-temporal dynamics of clot formation are well characterized, the cell-biological mechanisms of platelet recruitment to inflammatory micro-environments remain incompletely understood. Here we identify Arp2/3-dependent lamellipodia formation as a prominent morphological feature of immune-responsive platelets. Platelets use lamellipodia to scan for fibrin(ogen) deposited on the inflamed vasculature and to directionally spread, to polarize and to govern haptotactic migration along gradients of the adhesive ligand. Platelet-specific abrogation of Arp2/3 interferes with haptotactic repositioning of platelets to microlesions, thus impairing vascular sealing and provoking inflammatory microbleeding. During infection, haptotaxis promotes capture of bacteria and prevents hematogenic dissemination, rendering platelets gate-keepers of the inflamed microvasculature. Consequently, these findings identify haptotaxis as a key effector function of immune-responsive platelets.

NK cell-derived exosomes improved lung injury in mouse model of Pseudomonas aeruginosa lung infection.

BACKGROUND: Pseudomonas aeruginosa (PA) is one of the most common bacteria that causes lung infection in hospital. The aim of our study is to explore the role and action mechanism of NK cells in lung PA infection. METHODS: In this present study, 2.5 × 108 CFU/mouse PA was injected into murine trachea to make lung PA infection mouse model. Anti-asialo GM1 was used to inhibit NK cell. The percentage of NK cells was ensured by flow cytometry, and the M1- and M2-polarized macrophages were determined by flow cytometry, qRT-PCR, and ELISA assay. Besides, H&E staining was performed to ensure the pathological changes in lung tissues. Transmission electron microscopy and western blot were carried out to identify the exosome. RESULTS: Here, in the mouse model of PA lung infection, NK cell depletion caused M2 polarization of lung macrophage, and exacerbated PA-induced lung injury. Next, our data shown that M2 macrophage polarization was enhanced when the generation of NK cell-derived exosome was blocked in the co-culture system of NK cells and macrophages. Subsequently, we demonstrated that NK cells promoted M1 macrophage polarization both in PA-infected macrophage and the mouse model of PA lung infection, and attenuated lung injury through exosome. CONCLUSION: Overall, our data proved that NK cell may improve PA-induced lung injury through promoting M1 lung macrophage polarization by secreting exosome. Our results provide a new idea for the treatment of PA lung infection.

Potential hazardous effects of printing room PM2.5 exposure include promotion of lung inflammation and subsequent injury.

There have been few studies investigating the potential effects of indoor sources of particulate matter on human health. In this study, the effect of different concentrations of fine particulate matter (PM2.5) collected from a printing room on lung health was examined using cultured cells and a mouse model. Further, the mechanism of lung injury was examined. The results indicated that PM2.5 significantly enhanced malondialdehyde activity (P<0.05), decreased superoxide dismutase activity (P<0.05), upregulated the expression of pro­inflammatory factors including interleukin (IL)­1ß, tumor necrosis factor­, IL­6 and downregulated the expression of the inflammatory factor IL­2 (P<0.05). Western blot analysis indicated that PM2.5 significantly enhanced expression of phosphorylated (p)­ERK relative to total ERK, cyclooxygenase­2, p­anti­nuclear­factor­κB (p­NF­κB) relative to NF­κB, transforming growth factor­ß1 and Bax relative to Bcl­2 in inflammation (P<0.05), fibrosis and apoptosis signaling pathways. Furthermore, the results revealed that exposure was associated with an increased abundance of pathogens including Burkholderiales, Coriobacteriia, and Betaproteobacteria in in the lungs. In conclusion, exposure to PM2.5 from a printing room significantly increased inflammation, fibrosis, apoptosis and the abundance of pathogenic bacteria, indicating that exposure is potential threat to individuals who spend a significant amount of time in printing rooms.

MALDI-MSI spatially maps N-glycan alterations to histologically distinct pulmonary pathologies following irradiation.

Radiation-induced lung injury is a highly complex combination of pathological alterations that develop over time and severity of disease development is dose-dependent. Following exposures to lethal doses of irradiation, morbidity and mortality can occur due to a combination of edema, pneumonitis and fibrosis. Protein glycosylation has essential roles in a plethora of biological and immunological processes. Alterations in glycosylation profiles have been detected in diseases ranging from infection, inflammation and cancer. We utilized mass spectrometry imaging to spatially map N-glycans to distinct pathological alterations during the clinically latent period and at 180 days post-exposure to irradiation. Results identified alterations in a number of high mannose, hybrid and complex N-glycans that were localized to regions of mucus and alveolar-bronchiolar hyperplasia, proliferations of type 2 epithelial cells, accumulations of macrophages, edema and fibrosis. The glycosylation profiles indicate most alterations occur prior to the onset of clinical symptoms as a result of pathological manifestations. Alterations in five N-glycans were identified as a function of time post-exposure. Understanding the functional roles N-glycans play in the development of these pathologies, particularly in the accumulation of macrophages and their phenotype, may lead to new therapeutic avenues for the treatment of radiation-induced lung injury.

N-acetylcysteine (NAC) Attenuating Apoptosis and Autophagy in RAW264.7 Cells in Response to Incubation with Mycolic Acid from Bovine Mycobacterium tuberculosis Complex.

Bovine tuberculosis is an airborne infectious disease caused by organisms of the Mycobacterium tuberculosis (MTB) complex. Mycolic acid (MA) is the main lipid component of the cell membrane of MTB. It is non-enzymatically reduced by NAD(P)H and further produces reactive oxygen species (ROS), which can cause oxidative stress in human cells. N-acetylcysteine (NAC) is a synthetic precursor of glutathione (GSH) and exhibits anti-ROS activity. However, the underlying mechanisms of its protective properties remain uncertain. Herein, after pre-incubation of RAW264.7 cells with NAC, the factors associated with apoptosis and autophagy were measured. Mechanistically, NAC could reduce MA-induced expression of pro-apoptotic and pro-autophagy proteins. At the mRNA level, NAC can inhibit AMPK and activate mTOR expression. The results indicate that NAC might regulate autophagy in RAW264.7 cells through the AMPK/mTOR pathway. To further prove the effect of NAC on MA, ICR mice were used to evaluate the lung injury. Hematoxylin-eosin (HE) staining was performed on the lung. The results show that NAC could reduce cell injury induced by MA. In conclusion, our research showed that NAC attenuates apoptosis and autophagy in response to incubation with mycolic acid.Bovine tuberculosis is an airborne infectious disease caused by organisms of the Mycobacterium tuberculosis (MTB) complex. Mycolic acid (MA) is the main lipid component of the cell membrane of MTB. It is non-enzymatically reduced by NAD(P)H and further produces reactive oxygen species (ROS), which can cause oxidative stress in human cells. N-acetylcysteine (NAC) is a synthetic precursor of glutathione (GSH) and exhibits anti-ROS activity. However, the underlying mechanisms of its protective properties remain uncertain. Herein, after pre-incubation of RAW264.7 cells with NAC, the factors associated with apoptosis and autophagy were measured. Mechanistically, NAC could reduce MA-induced expression of pro-apoptotic and pro-autophagy proteins. At the mRNA level, NAC can inhibit AMPK and activate mTOR expression. The results indicate that NAC might regulate autophagy in RAW264.7 cells through the AMPK/mTOR pathway. To further prove the effect of NAC on MA, ICR mice were used to evaluate the lung injury. Hematoxylin-eosin (HE) staining was performed on the lung. The results show that NAC could reduce cell injury induced by MA. In conclusion, our research showed that NAC attenuates apoptosis and autophagy in response to incubation with mycolic acid.

Shen-ling-bai-zhu-san ameliorates inflammation and lung injury by increasing the gut microbiota in the murine model of Streptococcus pneumonia-induced pneumonia.

BACKGROUND: Shen-ling-bai-zhu-san (SLBZS) regulates inflammation and gut microbiota which are associated with Streptococcus pneumoniae (Spn)-induced pneumonia. So, we studied the therapeutic effect of SLBZS and evaluated whether gut microbiota is associated with the effects of SLBZS in improving Spn-induced pneumonia. METHODS: Spn-induced pneumonia NIH mice were treated by SLBZS and cefixime. A CT scan was performed and Myeloperoxidase (MPO) activity in lung homogenates was determined using the MPO Colorimetric Assay Kit. Inflammation levels in lung homogenates were measured using ELISA. Bacterial load was coated on a TSAII sheep blood agar. Intestinal gut microbiota information was analyzed according to sequencing libraries. RESULTS: SLBZS decreased bacterial load, reduced wet/dry weight ratio, inhibited myeloperoxidase activity, reduced the neutrophils count, and ameliorated lung injury. Furthermore, SLBZS inhibited interleukin (IL)-1ß, IL-6, tumor necrosis factor-α, IL-2, IL-8, IL-12, and interferon-γ secretion and enhanced IL-10 secretion. These results suggest that SLBZS ameliorates lung injury in mice with Spn-induced pneumonia. Moreover, SLBZS reduced inflammatory cytokine levels in a concentration-dependent manner and increased gut microbiota abundance and diversity. After SLBZS treatment, bacteria such as Epsilonbacteraeota, Bacteroidetes, Actinobacteria, Proteobacteria, and Patescibacteria were significantly reduced, while Tenericutes and Firmicutes were significantly increased. CONCLUSION: SLBZS ameliorates inflammation, lung injury, and gut microbiota in mice with S. pneumoniae-induced pneumonia.

Interleukin-17 mediates lung injury by promoting neutrophil accumulation during the development of contagious caprine pleuropneumonia.

Contagious caprine pleuropneumonia (CCPP) is a highly contagious infectious disease of goats caused by Mycoplasma capricolum subspecies capripneumoniae (Mccp). CCPP outbreaks usually result in high morbidity and mortality of the affected goats, making this disease a major cause of economic losses to goat producers globally. However, the pathogenesis of CCPP remains unclear. Here, we show that IL-17-driven neutrophil accumulation is involved in the lung damage in CCPP goats. During CCPP development, intense inflammatory infiltrates could be observed in the injured lungs. Specifically, neutrophils were observed to be present within the alveoli. Increased IL-17 release drove the excessive influx of neutrophils into the lung, as IL-17 effectively stimulated the production of neutrophil chemoattractants from lung epithelial cells following Mccp infection. Our data highlight a critical role of IL-17-driven neutrophil accumulation in the pathogenesis of CCPP and suggest that IL-17 may potentially be a useful immunotherapeutic target for the treatment of CCPP.

Fermented black barley ameliorates lung injury induced by cooking oil fumes via antioxidant activity and regulation of the intestinal microbiome in mice.

To investigate the effect of fermented black barley on cooking oil fume (COF)-induced lung injury, male ICR mice were randomized into five groups: normal control (NC), fermented black barley treatment (NF), COF exposure (O), COF + fermented black barley treatment (OF) and COF + Lactobacillus treatment (OL). The exposure of mice to COF was performed for 5 min per day and 4 days per week for a total of 9 weeks, and the mice in the OF, NF and OL groups were administered fermented black barley or Lactobacillus continuously for 9 weeks (1 mL/100 g). Our results showed that the gamma-aminobutyric acid (GABA), total phenolic, and flavonoid contents significantly increased after fermentation (P < 0.01). In addition, fermented black barley significantly increased SOD activity in the lung tissue, decreased the wet pulmonary coefficient, inhibited the reduction of microbial diversity and richness, and upregulated genes involved in cilium assembly and the cilium axoneme. These findings support the notion that fermented black barley can ameliorate COF-induced lung injury in mice.

Patient outcomes associated with post-tuberculosis lung damage in Malawi: a prospective cohort study.

BACKGROUND: Post-tuberculosis lung damage (PTLD) is a recognised consequence of pulmonary TB (pTB). However, little is known about its prevalence, patterns and associated outcomes, especially in sub-Saharan Africa and HIV-positive adults. METHODS: Adult (≥15 years) survivors of a first episode of pTB in Blantyre, Malawi, completed the St George's Respiratory Questionnaire, 6-minute walk test, spirometry and high-resolution CT (HRCT) chest imaging at TB treatment completion. Symptom, spirometry, health seeking, TB-retreatment and mortality data were collected prospectively to 1 year. Risk factors for persistent symptoms, pulmonary function decline and respiratory-related health-seeking were identified through multivariable regression modelling. RESULTS: Between February 2016 and April 2017, 405 participants were recruited. Median age was 35 years (IQR: 28 to 41), 77.3% (313/405) had had microbiologically proven pTB, and 60.3% (244/403) were HIV-positive. At pTB treatment completion, 60.7% (246/405) reported respiratory symptoms, 34.2% (125/365) had abnormal spirometry, 44.2% (170/385) had bronchiectasis ≥1 lobe and 9.4% (36/385) had ≥1 destroyed lobe on HRCT imaging. At 1 year, 30.7% (113/368) reported respiratory symptoms, 19.3% (59/305) and 14.1% (43/305) of patients had experienced declines in FEV1 or FVC of ≥100 mL, 16.3% (62/380) had reported ≥1 acute respiratory event and 12.2% (45/368) had symptoms affecting their ability to work. CONCLUSIONS: PTLD is a common and under-recognised consequence of pTB that is disabling for patients and associated with adverse outcomes beyond pTB treatment completion. Increased efforts to prevent PTLD and guidelines for management of established disease are urgently needed. Low-cost clinical interventions to improve patient outcomes must be evaluated.

Sini decoction ameliorates interrelated lung injury in septic mice by modulating the composition of gut microbiota.

Our work used cecal ligation and puncture (CLP) mice model and 16S rDNA sequencing to explore whether the therapeutic mechanism of Sini Decoction (SND) on sepsis was related to the intestinal flora currently of concern. Twenty-four hours after surgery, tissues and serum from three groups (Control, CLP and CLP + SND) were collected for further analysis and colon contents were isolated for 16S rDNA analysis. Mortality, histological examination and inflammatory cytokines levels confirmed that the sepsis model was induced successfully and resulted in serious pathological damage, while all of these could be reversed by SND. In intestinal flora analysis, the microbial richness and abundance were recovered after SND treatment. Furthermore, at the phylum level, the abundance of Proteobacteria showed drastic increase after CLP. Similarly, CLP surgery significantly disrupted the balance of intestinal flora, with a huge increase of Escherichia-Shigella, a Gram-negative genus that might release lipopolysaccharide (LPS) and other genera. And these shifts could be defused by SND, indicating its function of regulating gut microbiota. This study demonstrates that SND could ameliorate the symptoms and pathology associated with sepsis in CLP model via modulating the flora in intestinal tract, which enriches a possible mechanism of SND's therapeutic effect.

Collateral damage: necroptosis in the development of lung injury.

Cell death is increasingly recognized as a driving factor in the development of acute lung injury. Necroptosis, an immunogenic regulated cell death program important in innate immunity, has been implicated in the development of lung injury in a diverse range of conditions. Characterized by lytic cell death and consequent extracellular release of endogenous inflammatory mediators, necroptosis can be both beneficial and deleterious to the host, depending on the context. Here, we review recent investigations linking necroptosis and the development of experimental lung injury. We assess the consequences of necroptosis during bacterial pneumonia, viral infection, sepsis, and sterile injury, highlighting increasing evidence from in vitro studies, animal models, and clinical studies that implicates necroptosis in the pathogenesis of ARDS. Lastly, we highlight current challenges in translating laboratory findings to the bedside.

Perinatal maternal antibiotic exposure augments lung injury in offspring in experimental bronchopulmonary dysplasia.

During the newborn period, intestinal commensal bacteria influence pulmonary mucosal immunology via the gut-lung axis. Epidemiological studies have linked perinatal antibiotic exposure in human newborns to an increased risk for bronchopulmonary dysplasia, but whether this effect is mediated by the gut-lung axis is unknown. To explore antibiotic disruption of the newborn gut-lung axis, we studied how perinatal maternal antibiotic exposure influenced lung injury in a hyperoxia-based mouse model of bronchopulmonary dysplasia. We report that disruption of intestinal commensal colonization during the perinatal period promotes a more severe bronchopulmonary dysplasia phenotype characterized by increased mortality and pulmonary fibrosis. Mechanistically, metagenomic shifts were associated with decreased IL-22 expression in bronchoalveolar lavage and were independent of hyperoxia-induced inflammasome activation. Collectively, these results demonstrate a previously unrecognized influence of the gut-lung axis during the development of neonatal lung injury, which could be leveraged to ameliorate the most severe and persistent pulmonary complication of preterm birth.