HSF1 Alleviates Brain Injury by Inhibiting NLRP3-Induced Pyroptosis in a Sepsis Model.

Background: Sepsis, which could cause a systemic inflammatory response, is a life-threatening disease with a high morbidity and mortality rate. There is evidence that brain injury may be related to severe systemic infection induced by sepsis. The brain injury caused by sepsis could increase the risk of mortality in septic patients, which seriously affects the septic patient's prognosis of survival. Although there remains a focus on sepsis research, clinical measures to prevent and treat brain injury in sepsis are not yet available, and the high mortality rate is still a big health burden. Therefore, it is necessary to investigate the new molecules or regulated pathways that can effectively inhibit the progress of sepsis. Objective: NLR family pyrin domain-containing 3 (NLRP3) increased in the procession of sepsis and functioned as the key regulator of pyroptosis. Heat shock factor 1 (HSF1) can protect organs from multiorgan dysfunction syndrome induced by lipopolysaccharides in mice, and NLRP3 could be inhibited by HSF1 in many organs. However, whether HSF1 regulated NLRP3 in sepsis-induced brain injury, as well as the detailed mechanism of HSF1 in brain injury, remains unknown in the sepsis model. In this research, we try to explore the relationship between HSF1 and NLRP3 in a sepsis model and try to reveal the mechanism of HSF1 inhibiting the process of brain injury. Methods: In this study, we used wild-type mice and hsf1 -/- mice for in vivo research and PC12 cells for in vitro research. Real-time PCR and Western blot were used to analyze the expression of HSF1, NLRP3, cytokines, and pyrolytic proteins. EthD-III staining was chosen to detect the pyroptosis of the hippocampus and PC12 cells. Results: The results showed that HSF1 is negatively related to pyroptosis. The pyroptosis in cells of brain tissue was significantly increased in the hsf1 -/- mouse model compared to hsf1 +/+ mice. In PC12 cells, hsf1 siRNA can upregulate pyroptosis while HSF1-transfected plasmid could inhibit the pyroptosis. HSF1 could negatively regulate the NLRP3 pathway in PC12 cells, while hsf1 siRNA enhanced the pyroptosis in PC12 cells, which could be reversed by nlrp3 siRNA. Conclusion: These results imply that HSF1 could alleviate sepsis-induced brain injury by inhibiting pyroptosis through the NLRP3-dependent pathway in brain tissue and PC12 cells, suggesting HSF1 as a potential molecular target for treating brain injury in sepsis clinical studies.

Impaired interferon-γ signaling promotes the development of silicosis.

Silicosis is caused by inhalation of crystalline silica dust particles and known as one of the most serious occupational diseases worldwide. However, little is known about intrinsic factors leading to disease susceptibility. Single-cell sequencing of bronchoalveolar lavage fluid cells of mine workers with silicosis and their co-workers who did not develop silicosis revealed that the impaired interferon (IFN)-γ signaling in myeloid cells was strongly associated with the occurrence of silicosis. Global or myeloid cell-specific deletion of interferon γ receptor (IFN-γR) markedly enhanced the crystalline silica-induced pulmonary injury in wild-type but not in NLRP3 deficient mice. In vitro, IFN-γ priming of macrophages suppressed the crystalline silica-induced NLRP3 inflammasome activation partly by inducing the formation of spacious phagosomes with relatively reduced ratio of crystalline silica/phagosomal areas volumes to resistant crystalline silica-induced lysosomal membrane damage. Thus, these findings provide molecular insights into the intricate mechanisms underlying innate immunity-mediated host responses to environmental irritants.

HSF1 Protects Sepsis-Induced Acute Lung Injury by Inhibiting NLRP3 Inflammasome Activation.

As an important transcription factor, heat shock factor 1 (HSF1) plays an endogenous anti-inflammation role in the body and can alleviate multiple organ dysfunction caused by sepsis, which contributes to an uncontrolled inflammatory response. The NLRP3 inflammasome is a supramolecular complex that plays key roles in immune surveillance. Inflammation is accomplished by NLRP3 inflammasome activation, which leads to the proteolytic maturation of IL-1ß and pyroptosis. However, whether HSF1 is involved in the activation of the NLRP3 inflammasome in septic acute lung injury (ALI) has not been reported. Here, we show that HSF1 suppresses NLRP3 inflammasome activation in transcriptional and post-translational modification levels. HSF1 can repress NLRP3 expression via inhibiting NF-κB phosphorylation. HSF1 can inhibit caspase-1 activation and IL-1ß maturation via promoting NLRP3 ubiquitination. Our finding not only elucidates a novel mechanism for HSF1-mediated protection of septic ALI but also identifies new therapeutic targets for septic ALI and related diseases.

Nicorandil alleviates cardiac remodeling and dysfunction post -infarction by up-regulating the nucleolin/autophagy axis.

OBJECTIVE: The present study aimed to investigate whether the drug nicorandil can improve cardiac remodeling after myocardial infarction (MI) and the underlying mechanisms. METHODS: Mouse MI was established by the ligation of the left anterior descending coronary artery and H9C2 cells were cultured to investigate the underlying molecular mechanisms. The degree of myocardial collagen (Col) deposition was evaluated by Masson's staining. The expressions of nucleolin, autophagy and myocardial remodeling-associated genes were measured by Western blotting, qPCR, and immunofluorescence. The apoptosis of myocardial tissue cells and H9C2 cells were detected by TUNEL staining and flow cytometry, respectively. Autophagosomes were observed by transmission electron microscopy. RESULTS: Treatment with nicorandil mitigated left ventricular enlargement, improved the capacity of myocardial diastolic-contractility, decreased cardiomyocyte apoptosis, and inhibited myocardial fibrosis development post-MI. Nicorandil up-regulated the expression of nucleolin, promoted autophagic flux, and decreased the expressions of TGF-ß1 and phosphorylated Smad2/3, while enhanced the expression of BMP-7 and phosphorylated Smad1 in myocardium. Nicorandil decreased apoptosis and promoted autophagic flux in H2O2-treated H9C2 cells. Autophagy inhibitors 3-methyladenine (3MA) and chloroquine diphosphate salt (CDS) alleviated the effects of nicorandil on apoptosis. Knockdown of nucleolin decreased the effects of nicorandil on apoptosis and nicorandil-promoted autophagic flux of cardiomyocytes treated with H2O2. CONCLUSIONS: Treatment with nicorandil alleviated myocardial remodeling post-MI through up-regulating the expression of nucleolin, and subsequently promoting autophagy, followed by regulating TGF-ß/Smad signaling pathway.

Pentraxin-3 Is a Strong Biomarker of Sepsis Severity Identification and Predictor of 90-Day Mortality in Intensive Care Units via Sepsis 3.0 Definitions.

BACKGROUND: Sepsis is the leading cause of mortality in intensive care units (ICUs). However, early diagnosis and prognosis of sepsis and septic shock are still a great challenge. Pentraxin-3 (PTX3) was shown to be associated with the severity and outcome of sepsis and septic shock. This study was carried out to investigate the diagnostic and prognostic value of PTX3 in patients with sepsis and septic shock based on Sepsis 3.0 definitions. METHODS: In this single-center prospective observational study, all patients' serum was collected for biomarker measurements within 24 h after admission. Logistic and Cox regression analyses were used to identify the potential biomarkers of diagnosis, severity stratification, and prediction. RESULTS: Serum levels of PTX3 were significantly increased on the first day of ICU admission, while septic shock patients had highest PTX3 levels than other groups. A combination between PTX3 and procalcitonin (PCT) could better discriminate sepsis and septic shock, and PTX3 was an independent predictor of mortality in sepsis and septic shock patients. CONCLUSION: PTX3 may be a robust biomarker to classify the disease severity and predict the 90-day mortality of sepsis and septic shock based on the latest Sepsis 3.0 definitions.

Identification of pathogen(s) in infectious diseases using shotgun metagenomic sequencing and conventional culture: a comparative study.

BACKGROUND: Early and accurate diagnosis of microorganism(s) is important to optimize antimicrobial therapy. Shotgun metagenomic sequencing technology, an unbiased and comprehensive method for pathogen identification, seems to potentially assist or even replace conventional microbiological methodology in the diagnosis of infectious diseases. However, evidence in clinical application of this platform is relatively limited. METHODS: To evaluate the capability of shotgun metagenomic sequencing technology in clinical practice, both shotgun metagenomic sequencing and conventional culture were performed in the PCR-positive body fluid specimens of 20 patients with suspected infection. The sequenced data were then analyzed for taxonomic identification of microbes and antibiotic resistance gene prediction using bioinformatics pipeline. RESULTS: Shotgun metagenomic sequencing results showed a concordance of 17/20 compared with culture results in bacterial detection, and a concordance of 20/20 compared with culture results in fungal detection. Besides, drug-resistant types annotated from antibiotic resistance genes showed much similarity with antibiotic classes identified by susceptibility tests, and more than half of the specimens had consistent drug types between shotgun metagenomic sequencing and culture results. CONCLUSIONS: Pathogen identification and antibiotic resistance gene prediction by shotgun metagenomic sequencing identification had the potential to diagnose microorganisms in infectious diseases, and it was especially helpful for multiple microbial co-infections and for the cases where standard culture approached failed to identify microorganisms.

A small molecule binding HMGB1 inhibits caspase-11-mediated lethality in sepsis.

Caspase-11, a cytosolic lipopolysaccharide (LPS) receptor, mediates lethal immune responses and coagulopathy in sepsis, a leading cause of death worldwide with limited therapeutic options. We previously showed that over-activation of caspase-11 is driven by hepatocyte-released high mobility group box 1 (HMGB1), which delivers extracellular LPS into the cytosol of host cells during sepsis. Using a phenotypic screening strategy with recombinant HMGB1 and peritoneal macrophages, we discovered that FeTPPS, a small molecule selectively inhibits HMGB1-mediated caspase-11 activation. The physical interaction between FeTPPS and HMGB1 disrupts the HMGB1-LPS binding and decreases the capacity of HMGB1 to induce lysosomal rupture, leading to the diminished cytosolic delivery of LPS. Treatment of FeTPPS significantly attenuates HMGB1- and caspase-11-mediated immune responses, organ damage, and lethality in endotoxemia and bacterial sepsis. These findings shed light on the development of HMGB1-targeting therapeutics for lethal immune disorders and might open a new avenue to treat sepsis.

Increased HSF1 Promotes Infiltration and Metastasis in Cervical Cancer via Enhancing MTDH-VEGF-C Expression.

PURPOSE: To explore the molecular mechanism of promoting cervical cancer by HSF1 in vivo and in vitro. METHODS: The expression of HSF1 in 110 paraffin-embedded cervical cancer sections of different grades was examined via immunohistochemistry analyses. Expression of HSF1 downstream targets Metadherin (MTDH), VEGF-C and CD31 were studied using immunohistochemistry analyses. HSF1 transcriptional activity in the MTDH promoter region was detected by EMSA, CHIP and luciferase. Cell proliferation and clonality were detected by MTT and clonal formation assay. Cell migration and invasion ability were investigated by scratch analysis and transwell assay. HSF1-mediated tumorigenesis in vivo was examined in xenograft models. RESULTS: HSF1 expression of cervical cancer cell line was increased compared to normal human cervical tissues. HSF1 enhanced the expression of MTDH, VEGF-C and CD31. HSF1 can combine with MTDH promoter to promote the expression of MTDH. HSF1 enhanced HeLa cell proliferation and clone formation. Furthermore, HSF1 increased HeLa cells migration and invasion in vitro. In the transplanted tumor model, HSF1 inhibited tumor growth in vivo after interference, and reduced the expression of MTDH, VEGF-C and CD31. DISCUSSION: HSF1 can promote the proliferation, metastasis and invasion of cervical cancer.

Heparin prevents caspase-11-dependent septic lethality independent of anticoagulant properties.

Heparin, a mammalian polysaccharide, is a widely used anticoagulant medicine to treat thrombotic disorders. It is also known to improve outcomes in sepsis, a leading cause of mortality resulted from infection-induced immune dysfunction. Whereas it is relatively clear how heparin exerts its anticoagulant effect, the immunomodulatory mechanisms enabled by heparin remain enigmatic. Here, we show that heparin prevented caspase-11-dependent immune responses and lethality in sepsis independent of its anticoagulant properties. Heparin or a chemically modified form of heparin without anticoagulant function inhibited the alarmin HMGB1-lipopolysaccharide (LPS) interaction and prevented the macrophage glycocalyx degradation by heparanase. These events blocked the cytosolic delivery of LPS in macrophages and the activation of caspase-11, a cytosolic LPS receptor that mediates lethality in sepsis. Survival was higher in septic patients treated with heparin than those without heparin treatment. The identification of this previously unrecognized heparin function establishes a link between innate immune responses and coagulation.

Inhibition of aerobic glycolysis alleviates sepsis­induced acute kidney injury by promoting lactate/Sirtuin 3/AMPK­regulated autophagy.

Metabolism reprogramming influences the severity of organ dysfunction, progression to fibrosis, and development of disease in acute kidney injury (AKI). Previously we showed that inhibition of aerobic glycolysis improved survival rates and protected septic mice from kidney injury. However, the underlying mechanisms remain unclear. In the present study, it was revealed that sepsis or lipopolysaccharide (LPS) enhanced aerobic glycolysis as evidenced by increased lactate production and upregulated mRNA expression of glycolysis­related genes in kidney tissues and human renal tubular epithelial (HK­2) cells. The aerobic glycolysis inhibitor 2­deoxy­D­glucose (2­DG) downregulated glycolysis, and improved kidney injury induced by sepsis. 2­DG treatments increased the expression of sirtuin 3 (SIRT3) and phosphorylation­AMP­activated protein kinase (p­AMPK), following promoted autophagy and attenuated apoptosis of tubular epithelial cells in septic mice and in LPS­treated HK­2 cells. However, the glycolysis metabolite lactate downregulated SIRT3 and p­AMPK expression, inhibited autophagy and enhanced apoptosis in LPS­treated HK­2 cells. Furthermore, pharmacological blockade of autophagy with 3­methyladenine (3­MA) partially abolished the protective effect of 2­DG in sepsis­induced AKI. These findings indicated that inhibition of aerobic glycolysis protected against sepsis­induced AKI by promoting autophagy via the lactate/SIRT3/AMPK pathway.

HSF1 functions as a key defender against palmitic acid-induced ferroptosis in cardiomyocytes.

Palmitic acid (PA)-induced myocardial injury is considered a critical contributor to the development of obesity and type 2 diabetes mellitus (T2DM)-related cardiomyopathy. However, the underlying mechanism has not been fully understood. Here, we demonstrated that PA induced the cell death of H9c2 cardiomyoblasts in a dose- and time-dependent manner, while different ferroptosis inhibitors significantly abrogated the cell death of H9c2 cardiomyoblasts and primary neonatal rat cardiomyocytes exposed to PA. Mechanistically, PA decreased the protein expression levels of both heat shock factor 1 (HSF1) and glutathione peroxidase 4 (GPX4) in a dose- and time-dependent manner, which were restored by different ferroptosis inhibitors. Overexpression of HSF1 not only alleviated PA-induced cell death and lipid peroxidation but also improved disturbed iron homeostasis by regulating the transcription of iron metabolism-related genes (e.g., Fth1, Tfrc, Slc40a1). Additionally, PA-blocked GPX4 protein expression was evidently restored by HSF1 overexpression. Inhibition of endoplasmic reticulum (ER) stress rather than autophagy contributed to HSF1-mediated GPX4 expression. Moreover, GPX4 overexpression protected against PA-induced ferroptosis, whereas knockdown of GPX4 reversed the anti-ferroptotic effect of HSF1. Consistent with the in vitro findings, PA-challenged Hsf1-/- mice exhibited more serious ferroptosis, increased Slc40a1 and Fth1 mRNA expression, decreased GPX4 and TFRC expression and enhanced ER stress in the heart compared with Hsf1+/+ mice. Altogether, HSF1 may function as a key defender against PA-induced ferroptosis in cardiomyocytes by maintaining cellular iron homeostasis and GPX4 expression.

HSF1 Alleviates Microthrombosis and Multiple Organ Dysfunction in Mice with Sepsis by Upregulating the Transcription of Tissue-Type Plasminogen Activator.

Sepsis is a life-threatening complication of infection closely associated with coagulation abnormalities. Heat shock factor 1 (HSF1) is an important transcription factor involved in many biological processes, but its regulatory role in blood coagulation remained unclear. We generated a sepsis model in HSF1-knockout mice to evaluate the role of HSF1 in microthrombosis and multiple organ dysfunction. Compared with septic wild-type mice, septic HSF1-knockout mice exhibited a greater degree of lung, liver, and kidney tissue damage, increased fibrin/: fibrinogen deposition in the lungs and kidneys, and increased coagulation activity. RNA-seq analysis revealed that tissue-type plasminogen activator (t-PA) was upregulated in the lung tissues of septic mice, and the level of t-PA was significantly lower in HSF1-knockout mice than in wild-type mice in sepsis. The effects of HSF1 on t-PA expression were further validated in HSF1-knockout mice with sepsis and in vitro in mouse brain microvascular endothelial cells using HSF1 RNA interference or overexpression under lipopolysaccharide stimulation. Bioinformatics analysis, combined with electromobility shift and luciferase reporter assays, indicated that HSF1 directly upregulated t-PA at the transcriptional level. Our results reveal, for the first time, that HSF1 suppresses coagulation activity and microthrombosis by directly upregulating t-PA, thereby exerting protective effects against multiple organ dysfunction in sepsis.

Nucleolin regulates the proliferation of vascular smooth muscle cells in atherosclerotic via Aurora B.

Vascular smooth muscle cells (VSMCs) play a significant role in atherosclerosis. As a multifunctional protein, nucleolin (NCL) is involved in many important physiological and pathological processes. In this study, we aimed to investigate the role of nucleolin in VSMCs proliferation and cell cycle. The expression of nucleolin increased in VSMCs of mice with aortas advanced plaques. With the left common carotid-artery ligation-injury model, immunofluorescence staining revealed that nucleolin and Ki67 expression increased in VSMCs in mice left carotid artery compared with right carotid artery after surgery. POVPC or ox-LDL up-regulated nucleolin mRNA and protein expression in a dose- and time-dependent manner in HAVSMCs. POVPC (5µg/ml) or ox-LDL (50µg/ml) promoted the proliferation of HAVSMCs. Nucleolin ablation relieved the pro-proliferation role of VSMCs. The cell cycle assay and cell ability results showing that POVPC or ox-LDL increased the proliferation, but nucleolin ablation inhibited the proliferation of HAVSMCs. And nucleolin ablation can prevent DNA replication at S phase and induce cell cycle arrest in S phase. The bioinformatics database predicts protein-protein interactions with nucleolin and aurora B. Nucleolin overexpression and ablation affected the expression of aurora B. These findings indicate for the first time that nucleolin actively involved the proliferation of VSMCs via aurora B.

HSF1 Attenuates LPS-Induced Acute Lung Injury in Mice by Suppressing Macrophage Infiltration.

Heat shock factor 1 (HSF1) is a transcription factor involved in the heat shock response and other biological processes. We have unveiled here an important role of HSF1 in acute lung injury (ALI). HSF1 knockout mice were used as a model of lipopolysaccharide- (LPS-) induced ALI. Lung damage was aggravated, and macrophage infiltration increased significantly in the bronchoalveolar lavage fluid (BALF) and lung tissue of HSF-/- mice compared with the damage observed in HSF1+/+ mice. Upon LPS stimulation, HSF-/- mice showed higher levels of monocyte chemoattractant protein-1 (MCP-1) in the serum, BALF, and lung tissue and increased the expression of MCP-1 and chemokine (C-C motif) receptor 2 (CCR2) on the surface of macrophages compared with those in HSF1+/+. Electrophoretic mobility shift assays (EMSA) and dual luciferase reporter assays revealed that HSF1 could directly bind to heat shock elements (HSE) in the promoter regions of MCP-1 and its receptor CCR2, thereby inhibiting the expression of both genes. We concluded that HSF1 attenuated LPS-induced ALI in mice by directly suppressing the transcription of MCP-1/CCR2, which in turn reduced macrophage infiltration.

Shikonin Ameliorates LPS-Induced Cardiac Dysfunction by SIRT1-Dependent Inhibition of NLRP3 Inflammasome.

Shikonin (SHI) is an anti-inflammatory agent extracted from natural herbs. It is still unknown whether SHI ameliorates lipopolysaccharide (LPS)-induced cardiac dysfunction. This study aims to explore the protective effects of SHI on LPS-induced myocardial injury and its mechanism. The LPS-induced cardiac dysfunction mouse model was employed to investigate the protective effects of SHI. In the present study, we found that SHI treatment improved the survival rate and cardiac function and remarkably ameliorated the release of inflammatory cytokines and macrophage infiltration in heart tissue of LPS-treated mice. SHI also reduced lactate dehydrogenase (LDH) and cardiac troponin (cTn) release, cell inflammation, and apoptosis in LPS plus adenosine triphosphate (ATP)-treated H9c2 cells. In addition, SHI significantly upregulated silent information regulator 1 (SIRT1) expression and suppressed the upregulation of NOD-like receptor protein 3 (NLRP3), cleaved caspase-1, and caspase-1 activity in heart tissues induced by LPS. Meanwhile, we got the same results in LPS plus ATP-treated H9c2 cells in vitro. Further, SIRT1 inhibitor or siRNA partially blocked SHI-mediated upregulation of SIRT1 expression and downregulation of NLRP3, cleaved caspase-1, and caspase-1 activity in heart tissues induced by LPS. Therefore, we conclude that SHI ameliorates LPS-induced cardiac dysfunction by inhibiting SIRT1-dependent activation of NLRP3 inflammasomes and might be a promising therapeutic strategy for the treatment of LPS-induced cardiac dysfunction.

Heat Shock Factor 1 in Relation to Tumor Angiogenesis and Disease Progression in Patients With Pancreatic Cancer.

OBJECTIVE: In this article, the aims were to study the expression of heat shock factor 1 (HSF1) in patients with pancreatic cancer and to elucidate the relevance between HSF1, angiogenesis, clinicopathological factors, and prognosis. METHODS: Pancreatic cancer, paracancerous, and normal pancreatic tissues were collected. The HSF1 RNA and protein expressions were identified using quantitative real-time reverse transcription polymerase chain reaction and immunohistochemical staining. Associations of HSF1 and cluster of differentiation 34 with clinical variables and disease outcomes were investigated. RESULTS: Compared with the normal pancreatic and paracancerous tissue, HSF1 RNA and protein significantly showed higher expression in the pancreatic cancer tissue and was significantly associated with microvessel density. The high expression of HSF1 did not correspond to the patients' sex, age, carcinoembryonic antigen level, diameter of tumors, and locations; however, it corresponded significantly with carbohydrate antigen 19-9 level, lymph node metastasis, tumor node metastasis stage, differentiation degree, vascular invasion, and distant metastasis. The expression levels of HSF1 and cluster of differentiation 34 were significantly correlated with prognosis, disease specificity, and survival. The high expression of HSF1 would lead to worse prognosis and decrease in survival time and disease-free survival time. CONCLUSIONS: HSF1 expression level in pancreatic cancer tissue could be an ideal prognostic biomarker for risk stratification and a potential therapeutic target for patients with pancreatic cancer.

Metformin protects against ischaemic myocardial injury by alleviating autophagy-ROS-NLRP3-mediated inflammatory response in macrophages.

Myocardial ischaemia is usually accompanied by inflammatory response which plays a critical role in the myocardial healing and scar formation, while persistent inflammatory response contributes greatly to the myocardial remodeling and consequent heart failure. Metformin (Met), a widely used hypoglycemic drug, has increasingly been shown to exert remarkable cardioprotective effect on ischaemic myocardial injury such as acute myocardial infarction (AMI). However, the underlying mechanisms are still far from being fully understood. In this study, a mouse model of AMI was established through ligating the left anterior descending coronary artery (LAD), 100 mg/kg Met was given immediately after operation once daily for 3 days. It was demonstrated that Met effectively improved the cardiac haemodynamics (LVSP, LVEDP, +dp/dt, -dp/dt), diminished the infarct size, alleviated the disarrangement of myocardial cells and reduced the infiltration of inflammatory cells (macrophages, neutrophils and lymphocytes) in the heart of AMI mice. Mechanistically, Met decreased the expression of NLRP3 and enhanced the accumulation of LC3 puncta in F4/80-positive macrophages in the heart of AMI mice. Single cell suspension of cardiac macrophages was prepared from AMI mice and exhibited increased NLRP3 mRNA and protein expression. In contrast, Met decreased the expression of NLRP3 and p62, whereas increased the ratio of LC3II/LC3I. Additionally, both conditioned medium from H9c2 cardiomyocytes exposed to hydrogen peroxide (H9c2-H2O2-CM) and combination of mtDNA and ATP (mtDNA-ATP) increased the expression of NLRP3 and cleaved caspase-1 (p10) as well as intracellular ROS production in RAW264.7 macrophages, which were abrogated by Met treatment. Strikingly, chloroquine (CQ), 3-methyladenine (3-MA) and knockdown of autophagy-related gene (Atg5) abrogated the inhibitory effects of Met on H9c2-H2O2-CM and mtDNA-ATP-induced NLRP3 expression, release of IL-1ß and IL-18 as well as ROS production in RAW264.7 macrophages. Collectively, these findings suggest that Met protects against ischaemic myocardial injury through alleviating autophagy-ROS-NLRP3 axis-mediated inflammatory response in macrophages.

Effect of MIPU1 gene interference on biological behavior of U251 cell line. / shRNA干扰MIPU1åŸºå› å¯¹è„‘æ˜Ÿå½¢ç»†èƒžç˜¤U251细胞生物学行为的影响.

OBJECTIVES: To investigate effect of MIPU1 silence on proliferation, apoptosis, migration and invasion in U251 cells. METHODS: The shRNA recombinant plasmids targeting MIPU1 gene was transfected into U251 cells. Western blotting was used to identify the inhibitory efficiency at 72 h after transfection. The cell viability was measured by MTT colorimetric assay. Hoechest staining and caspase-3 activity were used to detect apoptosis. Then wound healing assay and transwell migration assay were applied to detect the migration and invasion of cells. RESULTS: The expression of MIPU1 protein was effectively knocked down in transfected cells (P<0.05). The cellular proliferation was obviously inhibited and apoptosis was increased in shRNA-transfected MIPU1 cells (all P<0.05). The migration and invasion ability of cells transfected with positive plasmid was lower than that in the control group (P<0.05). CONCLUSIONS: Down-regulation of MIPU1 can promote apoptosis while inhibit the proliferation, invasion, and migration of U251 cells.

Pharmacologic Blockade of 15-PGDH Protects Against Acute Renal Injury Induced by LPS in Mice.

Prostaglandin pathway plays multiple roles in various physiological and pathological conditions. The present study aimed to investigate the effect of 15-hydroxyprostaglandin dehydrogenase (15-PGDH), a key enzyme in the degradation of prostaglandins, on lipopolysaccharide (LPS)-induced acute kidney injury (AKI) in mice. In this study, male C57BL/6J mice were injected intraperitoneally with LPS (10 mg/kg). SW033291, a potent small-molecule inhibitor of 15-PGDH, was used to investigate the therapeutic potential of 15-PGDH inhibition on LPS-induced AKI. We discovered that the expression of 15-PGDH protein was upregulated in kidneys of LPS-stimulated mice, and it was mainly localized in the cytoplasm of renal tubular epithelial cells in renal cortex and outer medulla. SW033291 administration improved the survival rates of mice and attenuated renal injury of mice that were challenged by LPS. Additionally, inhibition of 15-PGDH also reversed LPS-induced apoptosis of renal cells, increased expression of anti-apoptotic protein Bcl-2, and downregulated expression of Fas, caspase-3, and caspase-8. Pretreatment of SW033291 enhanced autophagy in kidney cells after LPS stimulation. Our data also showed that inhibition of 15-PGDH relieved the level of lipid peroxidation and downregulated NADPH oxidase subunits induced by LPS in mice kidneys but had no significant effect on the release of inflammatory factors, such as IL-6, IL-1ß, TNF-α, and MCP-1. Our study demonstrated that inhibition of 15-PGDH could alleviate LPS-induced AKI by regulating the apoptosis, autophagy, and oxidative stress rather than inflammation in mice.

CARD9 promotes autophagy in cardiomyocytes in myocardial ischemia/reperfusion injury via interacting with Rubicon directly.

Autophagy in cardiomyocyte is involved in myocardial ischemia/reperfusion (M-I/R) injury. Caspase recruitment domain-containing protein 9 (CARD9) plays a critical role in cardiovascular diseases (CVDs) such as hypertension and cardiac fibrosis. However, its role in autophagy following M-I/R injury is yet to be fully elucidated. Here, we found that CARD9 expression increased in M-I/R mouse hearts, and in H9c2 or neonatal rat ventricular myocytes (NRVMs) in response to hypoxia/reoxygenation (H/R) or H2O2. CARD9-/- mice exhibited a significant cardiac dysfunction following M-I/R injury (30 min of left ascending coronary (LAD) ischemia and 12 h of reperfusion) compared to wild-type (WT) mice. CARD9 deletion impaired autophagy during M-I/R in vivo and in vitro, evidenced by decrease of microtubule-associated protein 1 light chain 3 (LC3) lipidation and p62 accumulation. Conversely, CARD9 overexpression increased autophagic flux as indicated by enhanced expression of LC3 II/LC3 I and a reduction in p62. The protective effect of CARD9 on cardiomyocytes against H/R-induced oxidative stress was abolished by treatment with autophagy inhibitors, 3-methyladenine (3-MA) or Bafilomycin A1(BafA1). CARD9 interacted with RUN domain Beclin-1-interacting cysteine-rich-containing (Rubicon), a negative regulator of autophagy, and enhanced UV-irradiation-resistance-associated gene (UVRAG)-Beclin1-phosphatidylinositol 3-kinase catalytic subunit type 3 (PI3KC3) interaction and UVRAG-Vps16-mediated Rab7 activation to promote autophagosome formation, maturation, and endocytosis. Ablation of Rubicon by siRNA effectively prevented the detrimental effect of CARD9 knockdown on cardiomyocytes. These results suggest that CARD9 has protective effects on the myocardium against M-I/R injury by activating autophagy and restoring autophagic flux in vivo and in vitro.