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AbstractContext Sepsis-induced acute lung injury (ALI) is a severe condition with limited effective therapeutics; nicotinamide mononucleotide (NMN) has been reported to exert anti-inflammatory activities.Objective This study explores the potential mechanisms by which NMN ameliorates sepsis-induced ALI in vivo and in vitro.Materials and methods Cultured MH-S cells and a murine model were used to evaluate the effect of NMN on sepsis-induced ALI. MH-S cells were stimulated with LPS (1 μg/mL) and NMN (500 μM) for 12 h grouping as control, LPS, and LPS + NMN. Cell viability, apoptotic status, and M1/2 macrophage-related markers were detected. The mice were pretreated intraperitoneally with NMN (500 mg/kg) and/or EX-527 (5 mg/kg) 1 h before LPS injection and randomized into 7 groups (n = 8): control, LPS, LPS + NMN, NMN, LPS + NMN + EX-527 (a SIRT1 inhibitor), LPS + EX-527, and EX-527. After 12 h, lung histopathology, W/D ratio, MPO activity, NAD+ and ATP levels, M1/2 macrophage-related markers, and expression of the SIRT1/NF-κB pathway were detected.Results In MH-S cells, NMN significantly decreased the apoptotic rate from 12.25% to 5.74%. In septic mice, NMN improved the typical pathologic findings in lungs and reduced W/D ratio and MPO activity, but increased NAD+ and ATP levels. Additionally, NMN suppressed M1 but promoted M2 polarization, and upregulated the expression of SIRT1, with inhibition of NF-κB-p65 acetylation and phosphorylation. Furthermore, inhibition of SIRT1 reversed the effects of NMN-induced M2 macrophage polarization.Conclusions NMN protects against sepsis-induced ALI by promoting M2 macrophage polarization via the SIRT1/NF-κB pathway, it might be an effective strategy for preventing or treating sepsis-induced ALI.

This study aimed to assess the prophylactic effects of Berberine on experimentally induced lung sepsis and examine its effects on selected cytokines, genes, and protein expression besides the histopathological evaluation. Berberine significantly reduced the wet/dry lung ratio, the broncho-alveolar lavage fluid (BALF) protein, cells, neutrophils percentage, and cytokines levels. In addition, pretreatment with Berberine decreased the myeloperoxidase (MPO) and malondialdehyde (MDA) levels and decreased gene expression of nuclear factor kappa B (NF-κB), monocyte chemoattractant protein-1 (MCP-1), and the intracellular adhesion molecule 1 (ICAM-1) by RT-qPCR analysis, revealing Berberine’s antioxidant and anti-inflammatory mode of action. Western blot analysis revealed increased peroxisome proliferator-activated receptor gamma (PPAR-γ) expression in the Berberine pretreated group compared to the cecal ligation and puncture (CLP) group, in which the histopathological examination evidenced this improvement. In conclusion, Berberine improved lung sepsis via its PPAR-γ mediated antioxidant and anti-inflammatory effects. [ABSTRACT FROM AUTHOR]

Introduction: Sepsis is a pathogenic syndrome of prolonged excessive inflammation and immunosuppression produced by invading pathogens. Programmed cell death 4 (PDCD4) may be implicated in a range of inflammatory lesions, and this study aimed to confirm the involvement of PDCD4 in septic lung injury. Materials and methods: Mice and bronchial epithelial 16HBE cells were separately subjected to CLP and LPS to generate in vivo and in vitro models. Following the level of PDCD4 was determined, the impacts of PDCD4 knockdown on mouse lung injury degree, inflammation, apoptosis, and pyroptosis levels were evaluated. Afterward, cells were treated with the NLRP3 agonist, and the influences of NLRP3 activation on the regulations of PDCD4 knockdown were determined. Results: PDCD4 was elevated following mice developed septic lung injury, PDCD4 knockdown ameliorated septic lung injury and reduced lung inflammation and apoptosis. Moreover, PDCD4 knockdown suppressed NLRP3-mediated pyroptosis, indicating that PDCD4 also mediated pyroptosis. According to cellular models, NLRP3 activation broke the effects of PDCD4 knockdown on cells. Conclusions: The current study reveals that PDCD4 governs NLRP3-mediated pyroptosis in septic lung injury. PDCD4 is not only related to apoptosis and expands the knowledge of PDCD4 regulation of different cell death modes. [ABSTRACT FROM AUTHOR]

Target biomarkers for H2 at both the protein and genome levels are still unclear. In this study, quantitative proteomics acquired from a mouse model were first analyzed. At the same time, functional pathway analysis helped identify functional pathways at the protein level. Then, bioinformatics on mRNA sequencing data were conducted between sepsis and normal mouse models. Differential expressional genes with the closest relationship to disease status and development were identified through module correlation analysis. Then, common biomarkers in proteomics and transcriptomics were extracted as target biomarkers. Through analyzing expression quantitative trait locus (eQTL) and genome-wide association studies (GWAS), colocalization analysis on Apoa2 and sepsis phenotype was conducted by summary-data-based Mendelian randomization (SMR). Then, two-sample and drug-target, syndrome Mendelian randomization (MR) analyses were all conducted using the Twosample R package. For protein level, protein quantitative trait loci (pQTLs) of the target biomarker were also included in MR. Animal experiments helped validate these results. As a result, Apoa2 protein or mRNA was identified as a target biomarker for H2 with a protective, causal relationship with sepsis. HDL and type 2 diabetes were proven to possess causal relationships with sepsis. The agitation and inhibition of Apoa2 were indicated to influence sepsis and related syndromes. In conclusion, we first proposed Apoa2 as a target for H2 treatment. [ABSTRACT FROM AUTHOR]

Target biomarkers for H2 at both the protein and genome levels are still unclear. In this study, quantitative proteomics acquired from a mouse model were first analyzed. At the same time, functional pathway analysis helped identify functional pathways at the protein level. Then, bioinformatics on mRNA sequencing data were conducted between sepsis and normal mouse models. Differential expressional genes with the closest relationship to disease status and development were identified through module correlation analysis. Then, common biomarkers in proteomics and transcriptomics were extracted as target biomarkers. Through analyzing expression quantitative trait locus (eQTL) and genome-wide association studies (GWAS), colocalization analysis on Apoa2 and sepsis phenotype was conducted by summary-data-based Mendelian randomization (SMR). Then, two-sample and drug-target, syndrome Mendelian randomization (MR) analyses were all conducted using the Twosample R package. For protein level, protein quantitative trait loci (pQTLs) of the target biomarker were also included in MR. Animal experiments helped validate these results. As a result, Apoa2 protein or mRNA was identified as a target biomarker for H2 with a protective, causal relationship with sepsis. HDL and type 2 diabetes were proven to possess causal relationships with sepsis. The agitation and inhibition of Apoa2 were indicated to influence sepsis and related syndromes. In conclusion, we first proposed Apoa2 as a target for H2 treatment.

Objective To analyze the effects of ghrelin on the pyroptosis pathway and the expression of inflammatory factors in septic lung injury, and explore its protective mechanism. Methods A total of 180 healthy male C57 BL/6 mice were divided into sham operation group (sham, n=24), cecal ligation and puncture group (CLP, n=78) and ghrelin group (n=78). The ghrelin group was intraperitoneally given ghrelin 12 nmol/kg at 3 h and 20 h after CLP surgery, while the other groups were given the same amount of normal saline. The 120-hour survival rate of each group was observed, and the bronchoalveolar lavage fluid (BALF) and lung tissues of mice in 6, 12 and 24 h after CLP group, ghrelin group and in 24 h for sham groups were collected respectively, and the total protein concentration and total cell number in BALF were detected. The expression of ghrelin as well as inflammatory cytokines such as IL-10, IL-6, TNF-α, IL-1β and IL-18 was tested by ELISA. Moreover, the expression of gasdermin D (GSDMD) was determined by immunofluorescence staining, and the levels of pyroptosis signal pathway proteins including NOD-like receptor protein (NLRP3), ASC, Caspase-1 and GSDMD were detected by qPCR and Western blotting. Results As compared with sham group, the mortality, pathological changes of lung tissue and levels of inflammatory factors (IL-10, IL-6, TNF-α, IL-1β and IL-18) in CLP group were significantly increased (P < 0.05); the level of ghrelin in the lung tissue was dropped, while those of NLRP3, ASC, Caspase-1 and GSDMD rose in the CLP group (P < 0.05). After administration of exogenous ghrelin, the death rate of septic lung injury mice was declined, the pathological damage of lung tissue was alleviated, and the expression levels of inflammatory cytokines and NLRP3, ASC, Caspase-1 and GSDMD were all decreased (P < 0.05). Conclusion Ghrelin improves the survival rate of septic lung injury mice and reduces the pathological changes of lung tissue, which may play a protective role by inhibiting the pathway of pyroptosis and alleviating inflammation.

Acute lung injury is the most common type of organ damage with high incidence and mortality in sepsis, which is a poorly understood syndrome of disordered inflammation. The aims of this study are to explore whether heat shock protein 70 (HSP70), as a molecular chaperone, attenuates the septic lung injury, and to understand the underlying mechanisms. In our study, treatment with HSP70 ameliorated the survival rate, dysfunction of lung, inflammation, and apoptosis in cecal ligation and puncture (CLP)-treated mice as well as in LPS-treated human alveolar epithelial cells. Furthermore, HSP70 interacted with KANK2, leading to reversed cell viability and reduced apoptosis-inducing factor (AIF) and apoptosis. Additionally, knockdown of KANK2 in epithelial cells and deletion of hsp70.1 gene in CLP mice aggravated apoptosis and tissue damage, suggesting that interaction of KANK2 and HSP70 is critical for protecting lung injury induced by sepsis. HSP70 plays an important role in protection of acute lung injury caused by sepsis through interaction with KANK2 to reduce AIF release and apoptotic cell. HSP70 is a novel potential therapeutic approach for attenuation of septic lung injury. [ABSTRACT FROM AUTHOR]

Context: Sepsis-induced acute lung injury (ALI) is a severe condition with limited effective therapeutics; nicotinamide mononucleotide (NMN) has been reported to exert anti-inflammatory activities., Objective: This study explores the potential mechanisms by which NMN ameliorates sepsis-induced ALI in vivo and in vitro ., Materials and Methods: Cultured MH-S cells and a murine model were used to evaluate the effect of NMN on sepsis-induced ALI. MH-S cells were stimulated with LPS (1 μg/mL) and NMN (500 μM) for 12 h grouping as control, LPS, and LPS + NMN. Cell viability, apoptotic status, and M1/2 macrophage-related markers were detected. The mice were pretreated intraperitoneally with NMN (500 mg/kg) and/or EX-527 (5 mg/kg) 1 h before LPS injection and randomized into 7 groups ( n  = 8): control, LPS, LPS + NMN, NMN, LPS + NMN + EX-527 (a SIRT1 inhibitor), LPS + EX-527, and EX-527. After 12 h, lung histopathology, W/D ratio, MPO activity, NAD + and ATP levels, M1/2 macrophage-related markers, and expression of the SIRT1/NF-κB pathway were detected., Results: In MH-S cells, NMN significantly decreased the apoptotic rate from 12.25% to 5.74%. In septic mice, NMN improved the typical pathologic findings in lungs and reduced W/D ratio and MPO activity, but increased NAD + and ATP levels. Additionally, NMN suppressed M1 but promoted M2 polarization, and upregulated the expression of SIRT1, with inhibition of NF-κB-p65 acetylation and phosphorylation. Furthermore, inhibition of SIRT1 reversed the effects of NMN-induced M2 macrophage polarization., Conclusions: NMN protects against sepsis-induced ALI by promoting M2 macrophage polarization via the SIRT1/NF-κB pathway, it might be an effective strategy for preventing or treating sepsis-induced ALI.

• KBTBD7 is highly expressed in the blood of sepsis patients. • Knockdown of KBTBD7 inhibits LPS-induced cellular inflammation and apoptosis. • Knockdown of KBTBD7 inhibits ferroptosis in alveolar epithelial cells. • Knockdown of KBTBD7 improves mitochondrial dysfunction. • KBTBD7 regulates the FOXA1/SLC7A11 pathway. • Knockdown of KBTBD7 improves LPS-induced inflammation and ferroptosis in alveolar epithelial cells via FOXA1. • Knockdown of KBTBD7 ameliorates septic lung injury in mice. Lung injury in sepsis is caused by an excessive inflammatory response caused by the entry of pathogenic microorganisms into the body. It is also accompanied by the production of large amounts of ROS. Ferroptosis and mitochondrial dysfunction have also been shown to be related to sepsis. Finding suitable sepsis therapeutic targets is crucial for sepsis research. BTB domain-containing protein 7 (KBTBD7) is involved in regulating inflammatory responses, but its role and mechanism in the treatment of septic lung injury are still unclear. In this study, we evaluated the role and related mechanisms of KBTBD7 in septic lung injury. In in vitro studies, we established an in vitro model by inducing human alveolar epithelial cells with lipopolysaccharide (LPS) and found that KBTBD7 was highly expressed in the in vitro model. KBTBD7 knockdown could reduce the inflammatory response by inhibiting the secretion of pro-inflammatory factors and inhibit the production of ROS, ferroptosis and mitochondrial dysfunction. Mechanistic studies show that KBTBD7 interacts with FOXA1, promotes FOXA1 expression, and indirectly inhibits SLC7A11 transcription. In vivo studies have shown that knocking down KBTBD7 improves lung tissue damage in septic lung injury mice, inhibits inflammatory factors, ROS production and ferroptosis. Taken together, knockdown of KBTBD7 shows an alleviating effect on septic lung injury in vitro and in vivo, providing a potential therapeutic target for the treatment of septic lung injury. [ABSTRACT FROM AUTHOR]

Acute lung injury is the most common type of organ damage with high incidence and mortality in sepsis, which is a poorly understood syndrome of disordered inflammation. The aims of this study are to explore whether heat shock protein 70 (HSP70), as a molecular chaperone, attenuates the septic lung injury, and to understand the underlying mechanisms. In our study, treatment with HSP70 ameliorated the survival rate, dysfunction of lung, inflammation, and apoptosis in cecal ligation and puncture (CLP)-treated mice as well as in LPS-treated human alveolar epithelial cells. Furthermore, HSP70 interacted with KANK2, leading to reversed cell viability and reduced apoptosis-inducing factor (AIF) and apoptosis. Additionally, knockdown of KANK2 in epithelial cells and deletion of hsp70.1 gene in CLP mice aggravated apoptosis and tissue damage, suggesting that interaction of KANK2 and HSP70 is critical for protecting lung injury induced by sepsis. HSP70 plays an important role in protection of acute lung injury caused by sepsis through interaction with KANK2 to reduce AIF release and apoptotic cell. HSP70 is a novel potential therapeutic approach for attenuation of septic lung injury.

Sepsis-induced lung injury is a lethal complication with no effective treatment options, affecting millions of people worldwide. Oroxylin A (OroA) is a natural flavonoid with potent anticancer effects, but its modulating effect on inflammation through microRNAs (miRs) is not apparent. In this report, we investigated the target genes of the miR pathway mediated by OroA and assessed the potential for novel treatments of septic lung injury. An miR array screening and quantitative polymerase chain reaction identified that miR-155-5p could be a candidate regulated by OroA. Bioinformatics analysis indicated that interferon regulatory factor-2-binding protein-2 (IRF2BP2) might be a target of miR-155-5p, and this hypothesis was verified through reporter assays. In addition, an immunoprecipitation assay demonstrated that OroA increased the binding activity of IRF2BP2 to the nuclear factor of activated T-cells 1 (NFAT1), causing inducible nitric oxide synthase to cause an inflammatory reaction. Finally, the direct injection of short hairpin RNA (shRNA)-miR-155-5p into the bone marrow of mice ameliorated LPS-induced acute lung injury and inflammation in mice. Our results provide new mechanistic insights into the role of the OroA-induced miR-155-5p-IRF2BP2-NFAT1 axis in sepsis, demonstrating that direct bone marrow injection of lentivirus containing shRNA-155-5p could prove to be a potential future clinical application in alleviating sepsis-induced acute lung injury. [ABSTRACT FROM AUTHOR]

[Display omitted] • GBP2 was rich in L-Exo which had the ability to cause lung injury in sepsis. • Increased GBP2 in L-Exo resulted in the activation of NLRP3 inflammasomes in epithelial cells. • GBP2 activated the NLRP3 inflammasomes partially dependent on the isoprenylation ability of GBP2 with the PYD domain of NLRP3 inflammasomes. Macrophages infiltration is a crucial factor causing Sepsis-associated acute lung injury (ALI). Accumulating evidence suggests macrophages-alveolar epithelial cells communication is proven to be critical in ALI. However, little is known regarding how activated macrophages regulated sepsis-associated ALI. To explore the role of macrophages-alveolar epithelial cells communication in the ALI process, our data revealed that Lipopolysaccharides-induced macrophages-derived exosomes (L-Exo) induced sepsis-associated ALI and caused alveolar epithelial cells damage. Moreover, Guanylate-binding protein 2 (GBP2) was significantly upregulated in L-Exo, and NLRP3 inflammasomes was the direct target of GBP2. Further experimentation showed that GBP2 inhibition in vitro and in vivo reserves L-Exo effects, while GBP2 overexpression in vitro and in vivo promotes L-Exo effects. These results demonstrated that L-Exo contains excessive GBP2 and promotes inflammation through targeting NLRP3 inflammasomes, which induced alveolar epithelial cells dysfunction and pyroptosis. These findings demonstrate that L-Exo exerted a deleterious effect on ALI by regulating the GBP2/NLRP3 axis, which might provide new insight on ALI prevention and treatment. [ABSTRACT FROM AUTHOR]

Tumor necrosis factor (TNF)‐α activates a diverse array of signaling pathways in vascular endothelial cells (ECs), leading to the inflammatory phenotype that contributes to the vascular dysfunction and neutrophil emigration in patients with sepsis. To date, it is not well understood what key regulator might coordinate signaling pathways to achieve inflammatory response in TNF‐α‐stimulated ECs. This study investigated the role of dual specificity phosphatase‐6 (DUSP6) in the regulation of endothelial inflammation. Using knockout mice, we found that DUSP6 is important for TNF‐α‐induced endothelial intercellular adhesion molecule‐1 (ICAM‐1) expression in aorta and in vein. Moreover, genetic deletion of Dusp6 in pulmonary circulation significantly alleviated the susceptibility of mice to lung injury caused by neutrophil recruitment during experimental sepsis induced by TNF‐α or lipopolysaccharide (LPS). The role of DUSP6 was further investigated in primary human umbilical vein endothelial cells (HUVECs). Employing RNAi approach in which endogenous DUSP6 was ablated, we showed a critical function of DUSP6 to facilitate TNF‐α‐induced ICAM‐1 expression and endothelial leukocyte interaction. Interestingly, DUSP6‐promoted endothelial inflammation is independent of extracellular signaling‐regulated kinase (ERK) signaling. On the other hand, inducible DUSP6 leads to activation of canonical nuclear factor (NF)‐κB‐mediated transcription of ICAM‐1 gene in TNF‐α‐stimulated human ECs. These results are the first to demonstrate a positive role of DUSP6 in endothelial inflammation‐mediated pathological process and the underlying mechanism through which DUSP6 promotes NF‐κB signaling in the inflamed ECs. Our findings suggest that manipulation of DUSP6 holds great potential for the treatment of acute inflammatory diseases. [ABSTRACT FROM AUTHOR]

Abstract: Asiaticoside (AS), a major triterpenoid saponin component isolated from Centella asiatica, has been described to exhibit antioxidant and anti-inflammatory activities. The present study aimed to determine the protective effects and the underlying mechanisms of AS on septic lung injury induced by cecal ligation and puncture (CLP). Mice were pretreated with the AS (45mg/kg) or AS as well as GW9662 at 1h before CLP, the survival, lung injury, inflammatory mediators and signaling molecules, and Peroxisome proliferator-activated receptor-γ (PPAR-γ) were determined 24h after CLP. The results showed that AS significantly decreased CLP-induced the mortality, lung pathological damage, the infiltration of mononuclear, polymorphonuclear (PMN) leucocytes and total proteins. Moreover, AS inhibited CLP-induced the activation of mitogen-activated protein kinases (MAPKs) and nuclear factor-κB (NF-κB), the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) protein in lung tissues, and the production of serum tumor necrosis factor (TNF-α) and interleukin-6 (IL-6). Interestingly, the expression of PPAR-γ protein in lung tissue was up-regulated by AS. Furthermore, GW9662 (the inhibitor of PPAR-γ) significantly reversed these beneficial effects of AS in septic mice. These findings suggest that AS could effectively protect from septic lung injury induced by CLP and the underlying mechanisms might be related to up-regulation of PPAR-γ expression to some extent, which inhibits MAPKs and NF-κB pathway. [Copyright &y& Elsevier]

Sepsis is a systemic inflammatory response syndrome with high mortality. It has been reported that brefeldin A-inhibited guanine nucleotide-exchange factor 1 (BIG1) is involved in the pathogenesis of sepsis. However, the mechanism is not fully elucidated. In the present study, we explored the role of BIG1 in mediating lipid raft-dependent macrophage inflammatory response and its impact on lung injury in murine sepsis. In vitro studies revealed that BIG1 deficiency reduces the upregulation and secretion of tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and IL-1β and inhibits the activation of the toll-like receptor 4 (TLR4)/myeloid differentiation primary response 88-dependent nuclear factor kappa-B signaling pathway induced by the lipopolysaccharide (LPS) treatment. Further experiments revealed that the inhibitory effects of BIG1 deficiency on LPS-induced inflammation are due to the upregulation of adenosine triphosphate-binding cassette transporter A1. This promotes the free-cholesterol efflux from lipid rafts and results in the reduction of lipid raft TLR4 content. The decrease in TLR4 content in lipid raft thereby inhibits the LPS-induced inflammatory response. Furthermore, using the cecal ligation and puncture-induced polymicrobial sepsis mouse model, we found that conditional knockout (cKO) of the myeloid cell BIG1 significantly reduced the serum concentrations of TNF-α, IL-6, and IL-1β, and downregulated their mRNA expressions in the lungs. Pathological analysis confirmed that the BIG1 cKO alleviated the sepsis-induced lung injury. These results revealed the crucial new role of BIG1 in mediating lipid raft-dependent macrophage inflammatory response. Hence, BIG1 may be a potential promising therapeutic target for the treatment of septic lung injury., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Sepsis-induced lung injury is a lethal complication with no effective treatment options, affecting millions of people worldwide. Oroxylin A (OroA) is a natural flavonoid with potent anticancer effects, but its modulating effect on inflammation through microRNAs (miRs) is not apparent. In this report, we investigated the target genes of the miR pathway mediated by OroA and assessed the potential for novel treatments of septic lung injury. An miR array screening and quantitative polymerase chain reaction identified that miR-155-5p could be a candidate regulated by OroA. Bioinformatics analysis indicated that interferon regulatory factor-2-binding protein-2 (IRF2BP2) might be a target of miR-155-5p, and this hypothesis was verified through reporter assays. In addition, an immunoprecipitation assay demonstrated that OroA increased the binding activity of IRF2BP2 to the nuclear factor of activated T-cells 1 (NFAT1), causing inducible nitric oxide synthase to cause an inflammatory reaction. Finally, the direct injection of short hairpin RNA (shRNA)-miR-155-5p into the bone marrow of mice ameliorated LPS-induced acute lung injury and inflammation in mice. Our results provide new mechanistic insights into the role of the OroA-induced miR-155-5p-IRF2BP2-NFAT1 axis in sepsis, demonstrating that direct bone marrow injection of lentivirus containing shRNA-155-5p could prove to be a potential future clinical application in alleviating sepsis-induced acute lung injury.

The author reflects on the role of p38 mitogen-activated protein kinase (MAPK) signaling in critical care. He cites the study of Muhammad Asaduzzaman and colleagues on p38 MAPK as a significant component of septic lung injury. The author argues that an increased characterization of the signaling response such as extracellular signal-regulated protein kinases and c-Jun NH2-terminal protein kinases will be of great interest.