Project description:Sepsis, a worldwide health crisis, is notorious for its high mortality rate, often attributed to the development of acute lung injury. The direct migration of intestinal immune cells to the lung as a mediator of acute lung injury remains unclear. Our study unveiled a process where cecal ligation and puncture-induced sepsis prompted a migration of γδT cells from the small intestine to the lung, subsequently triggering an overwhelming inflammatory response dominated by IL-17A.
Project description:Sepsis, a worldwide health crisis, is notorious for its high mortality rate, often attributed to the development of acute lung injury. The direct migration of intestinal immune cells to the lung as a mediator of acute lung injury remains unclear. Our study unveiled a process where cecal ligation and puncture-induced sepsis prompted a migration of γδT cells from the small intestine to the lung, subsequently triggering an overwhelming inflammatory response dominated by IL-17A.
Project description:To investigate the role of EZH2 in sepsis-induced acute lung injury, we established a mouse model of sepsis in which macrophages specifically knocked out EZH2.We then used RNA-seq data from lung tissues of four groups of mice for gene expression profiling.
Project description:The activation of pulmonary endothelial cells (ECs) triggers the occurrence of lung injury and is a hallmark of sepsis-associated acute respiratory distress syndrome(ARDS). Aberrant metabolism favoring glycolysis plays a pivotal role in the pathogenesis of sepsis-induced EC activation. Herein we demonstrate that glycolysis-related histone lactylation, represented by H3K14 lactylation (H3K14la), drives sepsis-associated EC activation and lung injury. Accordingly, H3K14la level is elevated in injured lung tissue and activated ECs. Inhibition of lactate production suppresses both H3K14la levels and EC activation in response to lipopolysaccharide (LPS). We also show that lactate-dependent H3K14la is enriched at the promoters of ferroptosis-related genes, thereby inducing ferroptosis in ECs, and inhibiting ferroptosis effectively ameliorates EC activation. Taken together, elevated lactate in sepsis modulates EC activation and lung injury via histone lactylation and manipulation of glycolysis/H3K14la/ferroptosis axis may provide novel therapeutic approaches for the treatment of sepsis-associated ARDS.
Project description:Gene expression profiling was performed in lung tissues from an animal model of sepsis challenged with injurious and non-injurious mechanical ventilation to unravel the molecular pathways involved in acute lung injury. Sepsis was induced in male Sprague Dawley rats by means of cecal ligation and puncture. Septic rats were randomly allocated to three distinct groups: spontaneous breathing, mechanically ventilated with high tidal volume with zero positive end expiratory pressure (PEEP) and with low tidal volume and 10 cmH2O of PEEP. Comparisons were performed against an unventilated control group.
Project description:Sepsis, a worldwide health crisis, is notorious for its high mortality rate, often attributed to the development of acute lung injury. In this context, the lung, being particularly vulnerable to septic damage, emerge as a primary battleground. The possible roles of the gut-lung axis mediated by the gut microbiota and its metabolic products in the context of acute lung injury have been documented. However, the direct migration of intestinal immune cells to the lung as a mediator of acute lung injury remains unclear. Our study unveiled a process where cecal ligation and puncture-induced sepsis prompted a migration of γδ T cells from the small intestine to the lung, subsequently triggering an overwhelming inflammatory response dominated by IL-17A. Small intestinal memory γδT17 cells (CD44+ IL-7Rhigh CD8low Ly6C–) were the major subtype of γδ T cells that migrated from the small intestine to the lung and aggravated acute lung injury. Moreover, the activation of the Wnt signaling in the alveolar macrophages during sepsis was identified as a driving factor for the subsequent CCL1 upregulation, which prompted the migration of small intestinal memory γδT17 cells to the lung. S-Ketamine (S-KT) treatment demonstrated a notable capacity to alleviate acute lung injury through dampening pulmonary Wnt/β-catenin signaling-mediated migration of small intestinal γδT17 cells to the lung. Our findings highlight the significant contribution of the direct migration of immune cells from the small intestine to the lung in sepsis-induced acute lung injury, and clrify the pathological significance of the localized elevation of IL-17A in the lung.
Project description:Acute lung injury (ALI) is associated with a high mortality rate; however, the underlying molecular mechanisms are poorly understood. The purpose of this study was to investigate the expression profile and related networks of long noncoding RNAs (lncRNAs), microRNAs (miRNAs), and mRNAs in lung tissue exosomes obtained from sepsis-induced ALI. A mouse model of sepsis was established using the cecal ligation and puncture method. RNA sequencing was performed using lung tissue exosomes obtained from mice in the sham and CLP groups. Hematoxylin-eosin staining, western blotting, immunofluorescence, quantitative real-time polymerase chain reaction, and nanoparticle tracking analysis were performed to identify relevant phenotypes, and bioinformatic algorithms were used to evaluate competitive endogenous RNA (ceRNA) networks.Thirty lncRNA-miRNA-mRNA interactions were identified, including two upregulated lncRNAs, 30 upregulated miRNAs, and two downregulated miRNAs. Based on the expression levels of DEmRNAs, DELncRNAs, and DEmiRNAs, 30 ceRNA networks were constructed. This study revealed, for the first time, biomarkers of lung tissue exosome RNA and the related networks of lncRNA in sepsis-induced ALI. We revealed a novel molecular mechanism of sepsis-induced ALI, which may support the diagnosis and treatment of sepsis-induced ALI.
Project description:Acute lung injury (ALI) is associated with a high mortality rate; however, the underlying molecular mechanisms are poorly understood. The purpose of this study was to investigate the expression profile and related networks of long noncoding RNAs (lncRNAs), microRNAs (miRNAs), and mRNAs in lung tissue exosomes obtained from sepsis-induced ALI. A mouse model of sepsis was established using the cecal ligation and puncture method. RNA sequencing was performed using lung tissue exosomes obtained from mice in the sham and CLP groups. Hematoxylin-eosin staining, western blotting, immunofluorescence, quantitative real-time polymerase chain reaction, and nanoparticle tracking analysis were performed to identify relevant phenotypes, and bioinformatic algorithms were used to evaluate competitive endogenous RNA (ceRNA) networks.Thirty lncRNA-miRNA-mRNA interactions were identified, including two upregulated lncRNAs, 30 upregulated miRNAs, and two downregulated miRNAs. Based on the expression levels of DEmRNAs, DELncRNAs, and DEmiRNAs, 30 ceRNA networks were constructed. This study revealed, for the first time, biomarkers of lung tissue exosome RNA and the related networks of lncRNA in sepsis-induced ALI. We revealed a novel molecular mechanism of sepsis-induced ALI, which may support the diagnosis and treatment of sepsis-induced ALI.
Project description:Acute Lung Injury (ALI) can cause Acute Respiratory Distress Syndrome (ARDS), a lethal condition with limited treatment options and currently a common global cause of death due to COVID-19-induced ALI. ARDS secondary to Transfusion-Related Acute Lung Injury (TRALI) has been recapitulated pre-clinically by anti-MHC-I antibody administration to LPS-primed mice. In this model, we demonstrated that inhibitors of PTP1B, a protein tyrosine phosphatase that regulates signaling pathways of fundamental importance to homeostasis and inflammation, prevented lung injury and increased survival. Treatment with PTP1B inhibitors attenuated the aberrant neutrophil function that drives ALI, and was associated with release of myeloperoxidase, suppression of Neutrophil Extracellular Trap (NET) formation, and inhibition of neutrophil migration. Mechanistically, reduced signaling through the CXCR4 chemokine receptor, particularly to the activation of mTOR, was essential for these effects, linking PTP1B in hibition to promoting an aged neutrophil phenotype. Considering dysregulated activation of neutrophils is implicated in sepsis and can cause collateral tissue damage, we demonstrated also that PTP1B inhibitors improved survival and ameliorated lung injury in the LPS-induced sepsis model. Our data highlight PTP1B inhibition for prevention of TRALI and ARDS from multiple etiologies.
Project description:Inflammation resolution is critical for sepsis induced acute lung injury (ALI) recovery. Interleukin-36 receptor (IL-36R) is a potent anti-inflammatory factor. However, its role in ALI resolution remains unclear. We investigated the effects of IL-36R during the ALI resolution process in a murine cecal ligation and puncture (CLP)-induced ALI model. Knockout IL-36R signaling aggravates CLP-induced lung injury, as manifested by elevated bacterial load and increased neutrophils recruitment to the lung. Thereafter, we used IL-36R knockout mice to discern the source cell of IL-36R during ALI. We found that IL-36R is predominantly generated by epithelial cells during the ALI process. Furthermore, we sorted lung epithelial cells on the ALI process. IL-36R-specific loss in epithelial cells leads to apoptosis through NF-κB pathway. Together, our findings identify molecules that are likely involved in sepsis induced lung injury that may inform biomarker and therapeutic development.