BACKGROUND Massive hepatocyte death is the core event in acute liver failure(ALF).Gasdermin D(GSDMD)-mediated pyroptosis is a type of highly inflammatory cell death.However,the role of hepatocyte pyroptosis and its me...BACKGROUND Massive hepatocyte death is the core event in acute liver failure(ALF).Gasdermin D(GSDMD)-mediated pyroptosis is a type of highly inflammatory cell death.However,the role of hepatocyte pyroptosis and its mechanisms of expanding inflammatory responses in ALF are unclear.AIM To investigate the role and mechanisms of GSDMD-mediated hepatocyte pyroptosis through in vitro and in vivo experiments.METHODS The expression of pyroptosis pathway-associated proteins in liver tissues from ALF patients and a hepatocyte injury model was examined by Western blot.GSDMD short hairpin RNA(shRNA)was used to investigate the effects of downregulation of GSDMD on monocyte chemotactic protein 1(MCP1)and its receptor CC chemokine receptor-2(CCR2)in vitro.For in vivo experiments,we used GSDMD knockout mice to investigate the role and mechanism of GSDMD in a D-galactose/lipopolysaccharide(D-Galn/LPS)-induced ALF mouse model.RESULTS The levels of pyroptosis pathway-associated proteins in liver tissue from ALF patients and a hepatocyte injury model increased significantly.The level of GSDMD-N protein increased most obviously(P<0.001).In vitro,downregulation of GSDMD by shRNA decreased the cell inhibition rate and the levels of MCP1/CCR2 proteins(P<0.01).In vivo,GSDMD knockout dramatically eliminated inflammatory damage in the liver and improved the survival of DGaln/LPS-induced ALF mice(P<0.001).Unlike the mechanism of immune cell pyroptosis that involves releasing interleukin(IL)-1βand IL-18,GSDMDmediated hepatocyte pyroptosis recruited macrophages via MCP1/CCR2 to aggravate hepatocyte death.However,this pathological process was inhibited after knocking down GSDMD.CONCLUSION GSDMD-mediated hepatocyte pyroptosis plays an important role in the pathogenesis of ALF,recruiting macrophages to release inflammatory mediators by upregulating MCP1/CCR2 and leading to expansion of the inflammatory responses.GSDMD knockout can reduce hepatocyte death and inflammatory responses,thus alleviating ALF.展开更多
AIM: Interleukin 8 (IL-8) mediates neutrophil trafficking via its receptors. Recent studies have shown that IL-8 is likely involved in the development and progression of erosive reflux esophagitis (RE), yet little is ...AIM: Interleukin 8 (IL-8) mediates neutrophil trafficking via its receptors. Recent studies have shown that IL-8 is likely involved in the development and progression of erosive reflux esophagitis (RE), yet little is known about the two distinct receptors, CXC receptor (CXCR)-1 and -2.The purpose of this study was to determine CXCR-1 and -2 messenger RNA expression levels in RE.METHODS: We studied 26 patients with RE and 15asymptomatic controls. Paired biopsy samples were taken from the esophagus 3 cm above the gastroesophageal junction; one biopsy was snap frozen for measurement of CXCR-1 and -2 mRNA levels by semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR), and another was formalin-fixed for histopathological evaluation.We also examined the association of the expression levels of CXCR-1 and -2 mRNA with histopathological hallmarks of RE.RESULTS: The relative CXCR-1 and -2 mRNA expression levels were rather decreased in esophageal mucosa of patients with RE, compared to those in normal esophagus of controls. There were no significant difference in the relative mRNA expression levels of CXCR-1 and -2 among endoscopic grades of RE based on the Los Angeles classification. Each histopathological hallmark of GERD was not associated with the expression levels of CXCR-1 and -2 mRNA.CONCLUSION: Apart from overexpression of IL-8, the relative expression levels of CXCR-1 and -2 mRNA were rather lower than expected in the affected esophageal mucosa of patients with RE.展开更多
基金Supported by the National Natural Science Foundation of China,No.81570543 and No.81560104
文摘BACKGROUND Massive hepatocyte death is the core event in acute liver failure(ALF).Gasdermin D(GSDMD)-mediated pyroptosis is a type of highly inflammatory cell death.However,the role of hepatocyte pyroptosis and its mechanisms of expanding inflammatory responses in ALF are unclear.AIM To investigate the role and mechanisms of GSDMD-mediated hepatocyte pyroptosis through in vitro and in vivo experiments.METHODS The expression of pyroptosis pathway-associated proteins in liver tissues from ALF patients and a hepatocyte injury model was examined by Western blot.GSDMD short hairpin RNA(shRNA)was used to investigate the effects of downregulation of GSDMD on monocyte chemotactic protein 1(MCP1)and its receptor CC chemokine receptor-2(CCR2)in vitro.For in vivo experiments,we used GSDMD knockout mice to investigate the role and mechanism of GSDMD in a D-galactose/lipopolysaccharide(D-Galn/LPS)-induced ALF mouse model.RESULTS The levels of pyroptosis pathway-associated proteins in liver tissue from ALF patients and a hepatocyte injury model increased significantly.The level of GSDMD-N protein increased most obviously(P<0.001).In vitro,downregulation of GSDMD by shRNA decreased the cell inhibition rate and the levels of MCP1/CCR2 proteins(P<0.01).In vivo,GSDMD knockout dramatically eliminated inflammatory damage in the liver and improved the survival of DGaln/LPS-induced ALF mice(P<0.001).Unlike the mechanism of immune cell pyroptosis that involves releasing interleukin(IL)-1βand IL-18,GSDMDmediated hepatocyte pyroptosis recruited macrophages via MCP1/CCR2 to aggravate hepatocyte death.However,this pathological process was inhibited after knocking down GSDMD.CONCLUSION GSDMD-mediated hepatocyte pyroptosis plays an important role in the pathogenesis of ALF,recruiting macrophages to release inflammatory mediators by upregulating MCP1/CCR2 and leading to expansion of the inflammatory responses.GSDMD knockout can reduce hepatocyte death and inflammatory responses,thus alleviating ALF.
文摘AIM: Interleukin 8 (IL-8) mediates neutrophil trafficking via its receptors. Recent studies have shown that IL-8 is likely involved in the development and progression of erosive reflux esophagitis (RE), yet little is known about the two distinct receptors, CXC receptor (CXCR)-1 and -2.The purpose of this study was to determine CXCR-1 and -2 messenger RNA expression levels in RE.METHODS: We studied 26 patients with RE and 15asymptomatic controls. Paired biopsy samples were taken from the esophagus 3 cm above the gastroesophageal junction; one biopsy was snap frozen for measurement of CXCR-1 and -2 mRNA levels by semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR), and another was formalin-fixed for histopathological evaluation.We also examined the association of the expression levels of CXCR-1 and -2 mRNA with histopathological hallmarks of RE.RESULTS: The relative CXCR-1 and -2 mRNA expression levels were rather decreased in esophageal mucosa of patients with RE, compared to those in normal esophagus of controls. There were no significant difference in the relative mRNA expression levels of CXCR-1 and -2 among endoscopic grades of RE based on the Los Angeles classification. Each histopathological hallmark of GERD was not associated with the expression levels of CXCR-1 and -2 mRNA.CONCLUSION: Apart from overexpression of IL-8, the relative expression levels of CXCR-1 and -2 mRNA were rather lower than expected in the affected esophageal mucosa of patients with RE.
