Project description:Sepsis-induced acute lung injury (ALI) is a severe clinical condition with a high mortality rate. Tangeretin, widely found in citrus fruits, has been reported to exert antioxidant and anti-inflammatory properties. However, whether Tangeretin protects against sepsis-induced ALI and the potential mechanisms remain unclear.We established ALI model via intraperitoneally injected with 5 mg/kg lipopolysaccharides (LPS) for 12 h. Tangeretin was applied intraperitoneally 30 min before LPS treatment. The lung tissue samples from both the LPS and LPS + TAN groups were subjected to RNA sequencing analysis, conducted by OE Biotech Co., Ltd. (Shanghai, China). We performed differential gene expression analysis using RNA-seq data between LPS and LPS/Tangeretin group.GSEA analysis between LPS and LPS/Tangeretin group showed that IL6_JAK_STAT3_SIGNALING, INFLAMMATORY_RESPONSE, TNFA_SIGNALING_VIA_NFKB were significantly enriched (Fig.3C-E). These results identified the anti-inflammatory effect of Tangeretin against sepsis-induced ALI.
Project description:Andrographolide sulfonate (Andro-S), a sulfonation derivative of andrographolide, is known to be effective in treating inflammation-related diseases, while the underlying mechanisms and global protein alterations in response to Andro-S remain unknown. This study aimed to investigate the pharmacological effects and potential targets of Andro-S in a murine model of acute lung injury (ALI). ALI was induced by aerosolized lipopolysaccharide (LPS) exposure before treatment with Andro-S. Inflammatory state of each treatment group was determined by histological analysis and quantification of inflammatory markers. Differentially expressed proteins in lung tissues were identified by an iTRAQ-based quantitative proteomic approach and further confirmed by immunohistochemistry analysis. Administration of Andro-S alleviated LPS-induced histological changes in the lung and reduced the expression of inflammatory markers in serum, bronchoalveolar fluid and lung tissues. Proteomic analysis identified 34 differentially expressed proteins from a total of 2,234 quantified proteins in the lung. According to bioinformatics analysis, neutrophil elastase (ELANE), Cathepsin G (CTSG) and myeloperoxidase (MPO), three neutrophil-derived proteases related to immune system process and defense responses to fungi were chosen as potential targets of Andro-S. Further immunohistochemistry analysis confirmed the inhibitory effects of Andro-S on LPS-induced ELANE, CTSG and MPO up-regulation. These results indicate that Andro-S suppressed the severity of LPS-induced ALI, possibly by attenuating the expression of and neutrophil-derived proteases.
Project description:Glutamine synthase (Glul) is a key enzyme to synthesize glutamine, but its function in acute liver injury (ALI) remains unclear. Here, we investigated the regulatory role of Glul on immnuity in LPS/D-GalN-induced ALI. The study firstly found that the expression of Glul in myeloid cells was inhibited following LPS/D-GalN challenge. Then myeloid-specific knockout Glul mice were generated, which showed more severe ALI and higher mortality due to the activation of monocyte-derived macrophages (MoMFs) and the secretion of CCL2, as well as the recruitment of CCR2+ monocytes. Notably, liver injury can be relieved with adeno-associated virus (AAV)-mediated hepatic delivery of Glul via tail vein injection in mice. In conclusion, this research validates the protective effect of Glul against ALI.
Project description:Our previous study showed that AKR and C57BL/6 mice to cigarette smoke increased lipopolysaccharide (LPS)- induced increased lung vascular permeability. Viremic AKR mice were more susceptible to LPS-induced ALI than C57 on prolonged exposure. In this study we compared the global gene expression patterns to determine the genetic basis for the strain dependent responses to cigarette smoke and LPS-induced ALI. We found AKR transcriptomic responses didnot overlap with C57 mice and AKR mice showed increased responses compared to C57 mice. Global gene expression analysis using microarray was used to dermine the mechanisms of strain dependent responses to cigarette smoking and LPS mediated ALI
Project description:Inflammation resolution is critical for acute lung injury (ALI) recovery. Interleukin (IL)-10 is a potent anti-inflammatory factor. However, its role in ALI resolution remains unclear. We investigated the effects of IL-10 during the ALI resolution process in a murine lipopolysaccharide (LPS)-induced ALI model. Blockade of IL-10 signaling aggravates LPS-induced lung injury, as manifested by elevated pro-inflammatory factors production and increased neutrophils recruitment to the lung .Thereafter, we used IL-10 GFP reporter mice to discern the source cell of IL-10 during ALI. We found that IL-10 is predominantly generated by B cells during the ALI recovery process. Furthermore, we used IL-10-specific loss in B-cell mice to elucidate the effect of B-cell-derived IL-10 on the ALI resolution process. IL-10-specific loss in B cells leads to increased pro-inflammatory cytokine expression, persistent leukocyte infiltration, and prolonged alveolar barrier damage. Mechanistically, B cell-derived IL-10 inhibits the activation and recruitment of macrophages and downregulates the production of chemokine KC that recruits neutrophils to the lung. Moreover, we found that IL-10 deletion in B cells leads to alterations in the cGMP–PKG signaling pathway. In addition, an exogenous supply of IL-10 promotes recovery from LPS-induced ALI, and IL-10-secreting B cells are present in sepsis-related ARDS. This study highlights that B cell-derived IL-10 is critical for the resolution of LPS-induced ALI and may serve as a potential therapeutic target.
Project description:Purpose: Acute lung injury (ALI) is a severe clinical disorder characterized by diffused capillary-alveolar barrier damage and noncardiogenic lung edema induced by excessive inflammation reactions. Nogo-B, a member of the reticulon 4 protein family, plays a critical role in modulating macrophages and neutrophils’ function in inflammation. Its role in ALI remains unclear. Methods: Pulmonary expression of Nogo-B was investigated in a LPS-induced ALI mice model. The effects and the underline mechanisms of Nogo-B expression on the severity of lung injury was assessed using histological examination, Bronchoalveolar lavage fluid (BALF) protein and inflammatory cells and cytokines measurement, and microarray analysis. Results: Nogo-B was normally highly expressed in the lungs of naïve C57BL/6 mice. Intra-tracheal instillation of LPS significantly repressed the Nogo-B expression in lung tissues and BALF cells of ALI mice. In addition, over-expression of pulmonary Nogo-B using an adenovirus vector which expresses a Nogo-B-RFP-3-flag fusion protein (Ad-Nogo-B) significantly prolonged the survival time of mice challenged with lethal dose of LPS. Histological results and BALF protein measurement convinced that Ad-Nogo-B treated mice had less severity of lung injury and alveolar protein exudation, as compared with control adenovirus treated mice (Ad-RFP). They also had higher MCP-1 secretion and alveolar macrophages infiltration, but lower neutrophils infiltration. Finally, using microarray analysis, we identified a protective gene, PTX3, was highly elevated in Ad-Nogo-B treated mice. Conclusions: Nogo-B played a protective role in LPS-induced ALI, which might exert its role through modulation of inflammatory response and PTX3 secretion. A total of 12 samples from mice treated with or without LPS in the presence of Ad-Nogo-B or Ad-RFP transfection (n=3 for each group)
Project description:Our studies demonstrated that Gm26917 localized in the cytoplasm of hepatic macrophages and globally regulated expressions of inflammatory genes and differentiation of macrophages. In vivo study showed that lentivirus-mediated gene silencing of Gm26917 attenuated liver inflammation and protected mice from LPS-induced ALI. Furthermore, mechanistic study showed that 3’- truncation of Gm26917 interacts with N-terminus of Annexin A1, a negative regulator of NF-κB signaling pathway. We also found that Gm26917 knockdown suppressed NF-κB activity by decreasing the ubiquitination of Annexin A1 and its interaction with NEMO. Besides, expression of Gm26917 in inflammatory macrophage was regulated by transcription factor forkhead box M1 (FOXM1). LPS treatment could dramatically increase the binding of FOXM1 to the promoter region of Gm26917 in macrophages. In sum, our findings suggest that lncRNA Gm26917 silencing protected against LPS-induced liver injury by regulating TLR4/NF-κB signaling pathway in macrophages.
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:Acute lung injury (ALI) refers to a clinical syndrome characterized by bilateral lung injury, severe lung diffuse failure and hypoxemia caused by non-cardiogenic pulmonary edema.Sepsis is the leading etiology of ALI and a common admission to the intensive care unit, which induces pulmonary inflammation leading disruption of endothelial-epithelial barriers by surge release of pro-inflammatory cytokines that increases the permeability of the alveolar-capillary membrane, pulmonary infiltration, and edema.Ultimately, gas exchange across the alveolar-capillary membrane is severely impaired and acute respiratory failure and hypoxia occur. ALI patients may suffer from pulmonary inflammation and hypoxia simultaneously or sequentially, those two pathophysiological processes may interact mutually and contribute together to the development of ALI. LPS is the most important biological mediator of sepsis induce secretion of inflammatory cytokines including TNF-α, IL-1, and IL-6 from many cell types in response to bacterial toxins. Thus LPS has been commonly used to establish inflammatory ALI models of rats and mice. Clinically, hypoxia commonly coexists with sepsis; however, the role of hypoxia on the development of inflammatory ALI is unclear. The understanding of interaction of hypoxia and inflammation in ALI is of the importance for the treatment of ALI.
Project description:Rationale: Geranylgeranyl pyrophosphate synthase large subunit 1 (GGPPS1), a catalase downstream of the mevalonate pathway, regulates various pathological processes through balancing the production of farnesyl pyrophosphate and geranylgeranyl pyrophosphate. We sought to investigate whether GGPPS1 plays a role in mediating acute lung injury (ALI) using a mouse model of inflammation. Methods: Lipopolysaccharide (LPS) was intra-tracheally instilled to induce ALI in lung specific GGPPS1 knockout and wild-type mice. Expression of GGPPS1 in lung tissues and alveolar epithelial cells (AECs) was examined at different time points. Alveolar exudate, neutrophil infiltration, lung injury and cell death were determined. Change in global gene expression in response to GGPPS1 depletion was measured using mRNA microarray and verified in vivo and in vitro. Results: GGPPS1 levels increased significantly in lung tissues from LPS-induced ALI mice, where it showed a time- and dose-dependent increase in alveolar epithelial cells. Specific deletion of pulmonary GGPPS1 reduced the alveolar exudate and attenuated the severity of lung injury through inhibiting apoptosis of AECs. However, GGPPS1 deletion had limited effect on neutrophil counts and TNF-α levels in alveolar fluids. Deletion of GGPPS1 inhibited LPS-induced inflammasome activation, in terms of IL-1β release and pyroptosis, by down-regulating NLRP3 expression. Conclusions: Inhibition of pulmonary GGPPS1 attenuated LPS-induced ALI, predominantly by suppressing NLRP3 inflammasome activation.