5-Hydroxymethylfurfural （5-HMF）, a water-soluble compound extracted from wine-processed Fructus corni, is a novel hepatic protectant for treating acute liver injury. The present study was designed to investigate the...5-Hydroxymethylfurfural （5-HMF）, a water-soluble compound extracted from wine-processed Fructus corni, is a novel hepatic protectant for treating acute liver injury. The present study was designed to investigate the protective effect of 5-HMF in human L02 hepatocytes injured by D-galactosamine （GAIN） and tumor necrosis factor-α （TNF-α） in vitro and to explore the underlying mechanisms of action. Our results showed that 5-HMF caused significant increase in the viability of L02 cells injured by GalN/TNF-α, in accordance with a dose-dependent decrease in apoptotic cell death confirmed by morphological and flow cytometric analyses. Based on immunofluorescence and Western blot assays, we found that GalN/TNF-α induced ER stress in the cells, as indicated by the disturbance of intracellular Ca^2＋ concentration, the activation of protein kinase RNA （PKR）-like ER kinase （PERK）, phosphorylation of eukaryotic initiation factor 2 alpha （eIF2α）, and expression of ATF4 and CHOP proteins, which was reversed by 5-HMF pre-treatment in a dose-dependent manner. The anti-apoptotic effect of 5-HMF was further evidenced by balancing the expression of Bcl-2 family members. In addition, the knockdown of PERK suppressed the expression of phospho-PERK, phospho-eIF2α, ATF4, and CHOP, resulting in a significant decrease in cell apoptosis after the treatment with GalN/TNF-α. 5-HMF could enhance the effects of PERK knockdown, protecting the cells against the GalN/TNF-α insult. In conclusion, these findings demonstrate that 5-HMF can effectively protect GalN/TNF-α-injured L02 hepatocytes against ER stress-induced apoptosis through the regulation of the PERK- eIF2α signaling pathway, suggesting that it is a possible candidate for liver disease therapy.展开更多
BACKGROUND Calpain-2 is a Ca^2+-dependent cysteine protease,and high calpain-2 activity can enhance apoptosis mediated by multiple triggers.AIM To investigate whether calpain-2 can modulate aberrant endoplasmic reticu...BACKGROUND Calpain-2 is a Ca^2+-dependent cysteine protease,and high calpain-2 activity can enhance apoptosis mediated by multiple triggers.AIM To investigate whether calpain-2 can modulate aberrant endoplasmic reticulum(ER)stress-related apoptosis in rat hepatocyte BRL-3A cells.METHODS BRL-3A cells were treated with varying doses of dithiothreitol(DTT),and their viability and apoptosis were quantified by 3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl-2-H-tetrazolium bromide and flow cytometry.The expression of ER stress-and apoptosis-related proteins was detected by Western blot analysis.The protease activity of calpain-2 was determined using a fluorescent substrate,Nsuccinyl-Leu-Leu-Val-Tyr-AMC.Intracellular Ca^2+content,and ER and calpain-2 co-localization were characterized by fluorescent microscopy.The impact of calpain-2 silencing by specific small interfering RNA on caspase-12 activation and apoptosis of BRL-3A cells was quantified.RESULTS DTT exhibited dose-dependent cytotoxicity against BRL-3A cells and treatment with 2 mmol/L DTT triggered BRL-3A cell apoptosis.DTT treatment significantly upregulated 78 kDa glucose-regulated protein,activating transcription factor 4,C/EBP-homologous protein expression by>2-fold,and enhanced PRKR-like ER kinase phosphorylation,caspase-12 and caspase-3 cleavage in BRL-3A cells in a trend of time-dependence.DTT treatment also significantly increased intracellular Ca^2+content,calpain-2 expression,and activity by>2-fold in BRL-3A cells.Furthermore,immunofluorescence revealed that DTT treatment promoted the ER accumulation of calpain-2.Moreover,calpain-2 silencing to decrease calpain-2 expression by 85%significantly mitigated DTT-enhanced calpain-2 expression,caspase-12 cleavage,and apoptosis in BRL-3A cells.CONCLUSION The data indicated that Ca^2+-dependent calpain-2 activity promoted the aberrant ER stress-related apoptosis of rat hepatocytes by activating caspase-12 in the ER.展开更多
AIM： To observe the relationship between ethanol-induced oxidative damage in human primary cultured hepatocytes and cytochrome P450 2E1 （CYP2E1） activity, in order to address if inhibition of CYP2E1 could attenuate...AIM： To observe the relationship between ethanol-induced oxidative damage in human primary cultured hepatocytes and cytochrome P450 2E1 （CYP2E1） activity, in order to address if inhibition of CYP2E1 could attenuate ethanol- induced cellular damage. METHODS： The dose-dependent （25-100 mmol/L） and time-dependent （0-24 h） exposures of primary human cultured hepatocytes to ethanol were carried out. CYP2E1 activity and protein expression were detected by spectrophotometer and Western blot analysis respectively. Hepatotoxicity was investigated by determination of lactate dehydrogenase （LDH） and aspartate transaminase （AST） level in hepatocyte culture supernatants, as well as the intracellular formation of malondialdehyde （MDA）. RESULTS： A dose-and time-dependent response between ethanol exposure and CYP2E1 activity in human hepatocytes was demonstrated. Moreover, there was a time-dependent increase of CYP2E1 protein after 100 mmol/L ethanol exposure. Meanwhile, ethanol exposure of hepatocytes caused a time-dependent increase of cellular MDA level, LDH, and AST activities in supernatants. Furthermore, the inhibitor of CYP2E1, diallyl sulfide （DAS） could partly attenuate the increases of MDA, LDH, and AST in human hepatocytes. CONCLUSION： A positive relationship between ethanolinduced oxidative damage in human primary cultured hepatocytes and CYP2E1 activity was exhibited, and the inhibition of CYP2E1 could partly attenuate ethanol-induced oxidative damage.展开更多
Erythropoietin-induced hepatocyte receptor A2(EphA2)is a receptor tyrosine kinase that plays a key role in the development and progression of a variety of tumors.This article reviews the expression of EphA2 in gastroi...Erythropoietin-induced hepatocyte receptor A2(EphA2)is a receptor tyrosine kinase that plays a key role in the development and progression of a variety of tumors.This article reviews the expression of EphA2 in gastrointestinal(GI)colorectal cancer(CRC)and its regulation of pyroptosis.Pyroptosis is a form of programmed cell death that plays an important role in tumor suppression.Studies have shown that EphA2 regulates pyrodeath through various signaling pathways,affecting the occurrence,development and metastasis of GI CRC.The overexpression of EphA2 is closely related to the aggressiveness and metastasis of GI CRC,and the inhibition of EphA2 can induce pyrodeath and improve the sensitivity of cancer cells to treatment.In addition,EphA2 regulates intercellular communication and the microenvironment through interactions with other cytokines and receptors,further influencing cancer progression.The role of EphA2 in GI CRC and its underlying mechanisms provide us with new perspectives and potential therapeutic targets,which have important implications for future cancer treatment.展开更多
The carcinogenic antioxidants,N-phenyl-1-naphthylamine (P1NA)and N-phenyl-2-naphthylamine (P2NA) were examined in vitro for biotransformation by rat hepatic microsomes and in freshly isolated hepatocytes. HPLC-analysi...The carcinogenic antioxidants,N-phenyl-1-naphthylamine (P1NA)and N-phenyl-2-naphthylamine (P2NA) were examined in vitro for biotransformation by rat hepatic microsomes and in freshly isolated hepatocytes. HPLC-analysis of hepatocyte incubations with revealed that phenols were the major metabolites in both cases. P1NA formed one phenolic metabolite only, while incubation with P2NA yielded two phenols identified as 6-hydroxy-P2NA and 4'-hydroxy-P2NA by cochromatography with authentic samples. β-naphthylamine, a metabolite indicating dephenylation of P2NA was not detectable.Metabolism studies with microsomes revealed that the phenols were formed by cytochrome P-450 dependent monooxygenases. Pretreatment of animals with phenobarbital and 3-methylcholanthrene both increased the rate of microsomal metabolism of P1NA and P2NA, indicating that more than one P-450 enzyme mediate the oxygenation reaction. Animal pretreatment with single and repeated doses of P1NA and P2NA did not markedly stimulate metabolism, but induced ethylmorphine demethylatior. in males and females and benzo (a)pyrene hydroxylation in females.展开更多
In this study, the effect of ascorbic acid 2-phosphate (Asc2P) was tested on porcine and rat mature hepatocytes in vitro. a). Asc2P increased the porcine, but not rat, albumin secretion and mRNA expression. The enhanc...In this study, the effect of ascorbic acid 2-phosphate (Asc2P) was tested on porcine and rat mature hepatocytes in vitro. a). Asc2P increased the porcine, but not rat, albumin secretion and mRNA expression. The enhancing effect of Asc2P on porcine C/EBP alpha mRNA was observed in porcine mature hepatocytes. These data suggested that Asc2P played an important role in the regulation of porcine albumin mRNA level. b). The enhancing effect of Asc2P on ammonium metabolic activity was also observed in porcine, but not rat, mature hepatocytes. The porcine ornithine transcarbamylase (OTC) and arginase mRNAs were augmented by Asc2P, indicating that Asc2P had a direct effect on the urea cycle. c). The porcine collagen type I and type III mRNA, but not type XII mRNA, were detected as well, sugessting that Asc2P did not have the effect on the non-parenchymal hepatocytes to induce collagen type I and III mRNA expression. d). Our RT-PCR analysis demonstrated that the porcine hepatocytes expressed the sodium-ascorbate co-transporters SVCT1 and SVCT2, however, the intensities of porcine sodium-ascorbate co-transporters SVCT1 and SVCT2 bands were not changed markedly. These findings indicated that the Asc2P had no effect on SVCT1 and SVCT2 mRNA expression. e). The enhancing effect of Asc2P on porcine albumin mRNA was inhibited by staurosporine, a portein kinase inhibitor. We conclude that the enhanced albumin mRNA by Asc2P might be due to activation of tyrosine protein kinase and/or PKC and the Asc2P enhanced porcine albumin mRNA mainly at the transcriptional step.展开更多
Hepatocytes were isolated from livers of adult male SpragueDawley rats and cultured in Williams'E Medium with 3 H thymidine. The effect of 5hydroxytryptamine (5HT) was investigated through adding various concentra...Hepatocytes were isolated from livers of adult male SpragueDawley rats and cultured in Williams'E Medium with 3 H thymidine. The effect of 5hydroxytryptamine (5HT) was investigated through adding various concentrations (10-810-3 mol/L) of 5HT to the hepatocyte cultures in the presence or absence of epidermal growth factor (EGF) and insulin. The involvement of 5HT2 receptor was examined by adding a 5HT2 receptor antagonist, ketanserin (10-6 mol/L), to some of the cultures containing 5HT. The increment of DNA synthesis was measured by 3 H thymidine incorporation. The results showed that 5HT2 (10-6 mol/L) significantly (P<005) increased the amount of DNA synthesis induced by EGF and insulin in the cultured adult rat hepaptocytes. The effect of 5HT in enhancing DNA synthesis began to appear at a concentration between 10-7 and 10-6 mol/L and reached maximum at concentrations of 10-4 mol/L. The enhancement of DNA synthesis by 5HT was significantly (P<005) antagonized by ketanserin, suggesting that this effect of 5HT was mediated by 5HT2 receptor subtype.展开更多
The influence of bilirubin on mRNA expression of cytochrome P450 (CYP), UDP-glucuronosyltransferase (UGT) and nuclear receptors in human hepatocytes was investigated. The treatment of the hepatocytes with 40 μg/mL bi...The influence of bilirubin on mRNA expression of cytochrome P450 (CYP), UDP-glucuronosyltransferase (UGT) and nuclear receptors in human hepatocytes was investigated. The treatment of the hepatocytes with 40 μg/mL bilirubin, which corresponds to hyperbilirubinemia, resulted in 1.7-fold increase of CYP2A6 mRNA compared to the vehicle control while CYP2A6 mRNA did not change after treatment with 1 μg/mL bilirubin, corresponding to physiologically normal level. No significant change of mRNA expression by 40 μg/mL bilirubin treatment was observed for CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP3A4 and CYP3A5, UGT1A1, UGT1A3, UGT1A6, UGT2B4, UGT2B7, UGT2B10 and UGT2B15, constitutive androstane receptor (CAR), pregnane X receptor (PXR), retinoid X receptor α (RXRα) and hepatocyte nuclear factor-4α (HNF-4α). The induction profile of bilirubin was different from that of rifampicin, a typical PXR activator. This study demonstrated that CYP2A6 can be induced by bilirubin in a concentration dependent manner.展开更多
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
基金supported by grants from Natural Science Foundation of Jiangsu Higher Education Institutions of China(No.13KJB360010)Jiangsu Collaborative Innovation Center of Traditional Chinese Medicine(TCM) Prevention and Treatment of Tumor(No.012092002002)+1 种基金China and Europe Taking Care of Healthcare Solutions,CHETCH(No.PIRSES-GA-2013-612589)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘5-Hydroxymethylfurfural （5-HMF）, a water-soluble compound extracted from wine-processed Fructus corni, is a novel hepatic protectant for treating acute liver injury. The present study was designed to investigate the protective effect of 5-HMF in human L02 hepatocytes injured by D-galactosamine （GAIN） and tumor necrosis factor-α （TNF-α） in vitro and to explore the underlying mechanisms of action. Our results showed that 5-HMF caused significant increase in the viability of L02 cells injured by GalN/TNF-α, in accordance with a dose-dependent decrease in apoptotic cell death confirmed by morphological and flow cytometric analyses. Based on immunofluorescence and Western blot assays, we found that GalN/TNF-α induced ER stress in the cells, as indicated by the disturbance of intracellular Ca^2＋ concentration, the activation of protein kinase RNA （PKR）-like ER kinase （PERK）, phosphorylation of eukaryotic initiation factor 2 alpha （eIF2α）, and expression of ATF4 and CHOP proteins, which was reversed by 5-HMF pre-treatment in a dose-dependent manner. The anti-apoptotic effect of 5-HMF was further evidenced by balancing the expression of Bcl-2 family members. In addition, the knockdown of PERK suppressed the expression of phospho-PERK, phospho-eIF2α, ATF4, and CHOP, resulting in a significant decrease in cell apoptosis after the treatment with GalN/TNF-α. 5-HMF could enhance the effects of PERK knockdown, protecting the cells against the GalN/TNF-α insult. In conclusion, these findings demonstrate that 5-HMF can effectively protect GalN/TNF-α-injured L02 hepatocytes against ER stress-induced apoptosis through the regulation of the PERK- eIF2α signaling pathway, suggesting that it is a possible candidate for liver disease therapy.
基金the National Natural Science Foundation of China,No.81560105the Department of Science and Technology of Guizhou Province,No.LH(2014)7074。
文摘BACKGROUND Calpain-2 is a Ca^2+-dependent cysteine protease,and high calpain-2 activity can enhance apoptosis mediated by multiple triggers.AIM To investigate whether calpain-2 can modulate aberrant endoplasmic reticulum(ER)stress-related apoptosis in rat hepatocyte BRL-3A cells.METHODS BRL-3A cells were treated with varying doses of dithiothreitol(DTT),and their viability and apoptosis were quantified by 3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl-2-H-tetrazolium bromide and flow cytometry.The expression of ER stress-and apoptosis-related proteins was detected by Western blot analysis.The protease activity of calpain-2 was determined using a fluorescent substrate,Nsuccinyl-Leu-Leu-Val-Tyr-AMC.Intracellular Ca^2+content,and ER and calpain-2 co-localization were characterized by fluorescent microscopy.The impact of calpain-2 silencing by specific small interfering RNA on caspase-12 activation and apoptosis of BRL-3A cells was quantified.RESULTS DTT exhibited dose-dependent cytotoxicity against BRL-3A cells and treatment with 2 mmol/L DTT triggered BRL-3A cell apoptosis.DTT treatment significantly upregulated 78 kDa glucose-regulated protein,activating transcription factor 4,C/EBP-homologous protein expression by>2-fold,and enhanced PRKR-like ER kinase phosphorylation,caspase-12 and caspase-3 cleavage in BRL-3A cells in a trend of time-dependence.DTT treatment also significantly increased intracellular Ca^2+content,calpain-2 expression,and activity by>2-fold in BRL-3A cells.Furthermore,immunofluorescence revealed that DTT treatment promoted the ER accumulation of calpain-2.Moreover,calpain-2 silencing to decrease calpain-2 expression by 85%significantly mitigated DTT-enhanced calpain-2 expression,caspase-12 cleavage,and apoptosis in BRL-3A cells.CONCLUSION The data indicated that Ca^2+-dependent calpain-2 activity promoted the aberrant ER stress-related apoptosis of rat hepatocytes by activating caspase-12 in the ER.
基金Supported by the National Science Foundation of China, No. 30271130
文摘AIM： To observe the relationship between ethanol-induced oxidative damage in human primary cultured hepatocytes and cytochrome P450 2E1 （CYP2E1） activity, in order to address if inhibition of CYP2E1 could attenuate ethanol- induced cellular damage. METHODS： The dose-dependent （25-100 mmol/L） and time-dependent （0-24 h） exposures of primary human cultured hepatocytes to ethanol were carried out. CYP2E1 activity and protein expression were detected by spectrophotometer and Western blot analysis respectively. Hepatotoxicity was investigated by determination of lactate dehydrogenase （LDH） and aspartate transaminase （AST） level in hepatocyte culture supernatants, as well as the intracellular formation of malondialdehyde （MDA）. RESULTS： A dose-and time-dependent response between ethanol exposure and CYP2E1 activity in human hepatocytes was demonstrated. Moreover, there was a time-dependent increase of CYP2E1 protein after 100 mmol/L ethanol exposure. Meanwhile, ethanol exposure of hepatocytes caused a time-dependent increase of cellular MDA level, LDH, and AST activities in supernatants. Furthermore, the inhibitor of CYP2E1, diallyl sulfide （DAS） could partly attenuate the increases of MDA, LDH, and AST in human hepatocytes. CONCLUSION： A positive relationship between ethanolinduced oxidative damage in human primary cultured hepatocytes and CYP2E1 activity was exhibited, and the inhibition of CYP2E1 could partly attenuate ethanol-induced oxidative damage.
基金Scientific Research Nurturing Fund of the First Affiliated Hospital of Shandong First Medical University&Shandong Provincial Qianfoshan Hospital,No.QYPY2020NSFC0609.
文摘Erythropoietin-induced hepatocyte receptor A2(EphA2)is a receptor tyrosine kinase that plays a key role in the development and progression of a variety of tumors.This article reviews the expression of EphA2 in gastrointestinal(GI)colorectal cancer(CRC)and its regulation of pyroptosis.Pyroptosis is a form of programmed cell death that plays an important role in tumor suppression.Studies have shown that EphA2 regulates pyrodeath through various signaling pathways,affecting the occurrence,development and metastasis of GI CRC.The overexpression of EphA2 is closely related to the aggressiveness and metastasis of GI CRC,and the inhibition of EphA2 can induce pyrodeath and improve the sensitivity of cancer cells to treatment.In addition,EphA2 regulates intercellular communication and the microenvironment through interactions with other cytokines and receptors,further influencing cancer progression.The role of EphA2 in GI CRC and its underlying mechanisms provide us with new perspectives and potential therapeutic targets,which have important implications for future cancer treatment.
文摘The carcinogenic antioxidants,N-phenyl-1-naphthylamine (P1NA)and N-phenyl-2-naphthylamine (P2NA) were examined in vitro for biotransformation by rat hepatic microsomes and in freshly isolated hepatocytes. HPLC-analysis of hepatocyte incubations with revealed that phenols were the major metabolites in both cases. P1NA formed one phenolic metabolite only, while incubation with P2NA yielded two phenols identified as 6-hydroxy-P2NA and 4'-hydroxy-P2NA by cochromatography with authentic samples. β-naphthylamine, a metabolite indicating dephenylation of P2NA was not detectable.Metabolism studies with microsomes revealed that the phenols were formed by cytochrome P-450 dependent monooxygenases. Pretreatment of animals with phenobarbital and 3-methylcholanthrene both increased the rate of microsomal metabolism of P1NA and P2NA, indicating that more than one P-450 enzyme mediate the oxygenation reaction. Animal pretreatment with single and repeated doses of P1NA and P2NA did not markedly stimulate metabolism, but induced ethylmorphine demethylatior. in males and females and benzo (a)pyrene hydroxylation in females.
文摘In this study, the effect of ascorbic acid 2-phosphate (Asc2P) was tested on porcine and rat mature hepatocytes in vitro. a). Asc2P increased the porcine, but not rat, albumin secretion and mRNA expression. The enhancing effect of Asc2P on porcine C/EBP alpha mRNA was observed in porcine mature hepatocytes. These data suggested that Asc2P played an important role in the regulation of porcine albumin mRNA level. b). The enhancing effect of Asc2P on ammonium metabolic activity was also observed in porcine, but not rat, mature hepatocytes. The porcine ornithine transcarbamylase (OTC) and arginase mRNAs were augmented by Asc2P, indicating that Asc2P had a direct effect on the urea cycle. c). The porcine collagen type I and type III mRNA, but not type XII mRNA, were detected as well, sugessting that Asc2P did not have the effect on the non-parenchymal hepatocytes to induce collagen type I and III mRNA expression. d). Our RT-PCR analysis demonstrated that the porcine hepatocytes expressed the sodium-ascorbate co-transporters SVCT1 and SVCT2, however, the intensities of porcine sodium-ascorbate co-transporters SVCT1 and SVCT2 bands were not changed markedly. These findings indicated that the Asc2P had no effect on SVCT1 and SVCT2 mRNA expression. e). The enhancing effect of Asc2P on porcine albumin mRNA was inhibited by staurosporine, a portein kinase inhibitor. We conclude that the enhanced albumin mRNA by Asc2P might be due to activation of tyrosine protein kinase and/or PKC and the Asc2P enhanced porcine albumin mRNA mainly at the transcriptional step.
文摘Hepatocytes were isolated from livers of adult male SpragueDawley rats and cultured in Williams'E Medium with 3 H thymidine. The effect of 5hydroxytryptamine (5HT) was investigated through adding various concentrations (10-810-3 mol/L) of 5HT to the hepatocyte cultures in the presence or absence of epidermal growth factor (EGF) and insulin. The involvement of 5HT2 receptor was examined by adding a 5HT2 receptor antagonist, ketanserin (10-6 mol/L), to some of the cultures containing 5HT. The increment of DNA synthesis was measured by 3 H thymidine incorporation. The results showed that 5HT2 (10-6 mol/L) significantly (P<005) increased the amount of DNA synthesis induced by EGF and insulin in the cultured adult rat hepaptocytes. The effect of 5HT in enhancing DNA synthesis began to appear at a concentration between 10-7 and 10-6 mol/L and reached maximum at concentrations of 10-4 mol/L. The enhancement of DNA synthesis by 5HT was significantly (P<005) antagonized by ketanserin, suggesting that this effect of 5HT was mediated by 5HT2 receptor subtype.
文摘The influence of bilirubin on mRNA expression of cytochrome P450 (CYP), UDP-glucuronosyltransferase (UGT) and nuclear receptors in human hepatocytes was investigated. The treatment of the hepatocytes with 40 μg/mL bilirubin, which corresponds to hyperbilirubinemia, resulted in 1.7-fold increase of CYP2A6 mRNA compared to the vehicle control while CYP2A6 mRNA did not change after treatment with 1 μg/mL bilirubin, corresponding to physiologically normal level. No significant change of mRNA expression by 40 μg/mL bilirubin treatment was observed for CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP3A4 and CYP3A5, UGT1A1, UGT1A3, UGT1A6, UGT2B4, UGT2B7, UGT2B10 and UGT2B15, constitutive androstane receptor (CAR), pregnane X receptor (PXR), retinoid X receptor α (RXRα) and hepatocyte nuclear factor-4α (HNF-4α). The induction profile of bilirubin was different from that of rifampicin, a typical PXR activator. This study demonstrated that CYP2A6 can be induced by bilirubin in a concentration dependent manner.
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.
