OBJECTIVE To investigate the mechanism of SIRT1/AMPK signaling pathway between hepatocytes and hepatic stellate cells(HSCs).METHODS Normal human Chang liver cells and human hepatic stellate cell line,LX-2 cells were t...OBJECTIVE To investigate the mechanism of SIRT1/AMPK signaling pathway between hepatocytes and hepatic stellate cells(HSCs).METHODS Normal human Chang liver cells and human hepatic stellate cell line,LX-2 cells were treated with SRT1720(10μmol·L^(-1))and AICAR(500μmol·L^(-1))prior to ethanol(50 mmol·L^(-1)) for 24 and 48 h.Cell viability was analyzed by methyl thiazolyl tetrazolium assay.SIRT1,AMPK and p-AMPK m RNA levels for 24 h and 48 h were analyzed by RT-PCR,SIRT1,AMPK and p-AMPK protein expressions in the supernatant at 24 and 48 h was detected by Western blot.RESULTS SRT1720 and AICAR effectively decreased LX-2 cell viabilities and exhibited scarcely little toxicity in human Chang liver cells.SRT1720 and AICAR attenuated collagen-I,α-smooth muscle actin(α-SMA)levels,activated liver kinase B-1(LKB1)and AMPK phosphorylation in ethanol treated LX-2 cells.Meanwhile,SRT1720 and AICAR enhanced SIRT1 expression mediated by ethanol both in Chang liver cells and LX-2 cells.Furthermore,SRT1720 and AICAR suppressed the expression of sterol regulatory element-binding protein-1(SREBP-1)to regulate fatty acid synthesis.CONCLUSION SIRT1 agonist and AMPK agonist blocked the crosstalk between hepatocytes and HSCs via SIRT1/AMPK signaling pathway to modulate hepatocytes accumulation of lipid and HSCs activation.展开更多
OBJECTIVE The pathological characteristics of nonalcoholic steatohepatitis(NASH)include liver steatosis,inflammation,and fibrosis.Fibrosis is the most severe and significant pathological feature in NASH.Effective drug...OBJECTIVE The pathological characteristics of nonalcoholic steatohepatitis(NASH)include liver steatosis,inflammation,and fibrosis.Fibrosis is the most severe and significant pathological feature in NASH.Effective drug treatment could reverse early liver fibrosis and is of significance to prevent NASH from progressing into cirrhosis and liver cancer.Identification of drug targets for NASH treatment has been an active research area and is essential for the development of anti-NASH medications.Naringenin(NGN)is a flavonoid compound rich in citrus fruits.Our preliminary data demonstrated that NGN reduced diet-induced lipid accumulation and inflammation in the mouse liver,but whether NGN can attenuate liver fibrosis of NASH is not known.METHODS To study the effect of NGN on NASH fibrosis.WT mice were fed with high fat diet(HFD)and injected intraperitoneally 20%carbon tetrachloride at the same time for 8 weeks to induce NASH,and NGN was administrated by gavage in the meantime.In vitro,LO2 cells and LX2 cells were stimulated by oleic acid(OA)combined with lipopolysaccharide(LPS),respectively.RESULTS Treating the WT mice with NGN 100 mg·kg^(-1)·d-1 significantly attenuated hepatic lipid accumulation,hepatic fibrosis,plasma ALT and AST levels,inhibited protein expression of p-ERK,p-FoxO3a in the mouse livers.In vitro,on OA and LPS stimulated LO2 or LX2 cells,NGN significantly promoted apoptosis of activated hepatic stellate cells while inhibited apoptosis of hepatocytes.Mechanism study indicated that NGN inhibited MAPK pathway and promoted activation of FoxO3a,consequently promoted apoptosis of the activated LX2 cells and inhibited liver fibrosis.CONCLUSION NGN preventes NASH fibrosis via regulating MAPK/FoxO3a pathway,thus promoting apoptosis of the activated hepatic stellate cells.展开更多
OBJECTIVE To investigate the effect of P2X7receptor(P2X7r)inhibition,using a specific inhibitor(A438079)to prevent the development of liver fibrosis on human hepatic stellate cells,LX-2.METHODS The supernatant from li...OBJECTIVE To investigate the effect of P2X7receptor(P2X7r)inhibition,using a specific inhibitor(A438079)to prevent the development of liver fibrosis on human hepatic stellate cells,LX-2.METHODS The supernatant from lipopolysaccharide(LPS)-stimulated RAW264.7 mouse macrophages was supplemented to LX-2 cells for 24 h.LX-2cells were primed with LPS for 4h and subsequently stimulated for 30 min with 3mmol·L-1 of adenosine 5′-triphosphate(ATP).A438079(10μmol·L-1)was supplemented to LX-2 cells 10 min prior to ATP.RESULTS Directly treated with LPS on LX-2 cells,mRNA expressions of IL-1β,IL-18 and IL-6 were increased,as well as P2X7 r.And caspase-1,ASC and NLRP3 mRNA expressions were increased with LPS stimulation.LPS stimulation also increasedα-SMA and collagenⅠ mRNA expressions.Interestingly treatment of LX-2cells with mediums from LPS-primed RAW264.7mouse macrophages exhibited greater increase of mRNA expressions of above genes than those in LX-2directly treated with LPS.Pretreatment of directly or indirectly LPS-stimulated LX-2 cells with A438079 both suppressed IL-1βmRNA expression.In addition treatment of LPS-primed LX-2 cells with 3mmol·L-1 ATP induced the significant increase of IL-1β,IL-6,caspase-1,pannexin-1,α-SMA and collagenⅠ mRNA expression,the increasing ofα-SMA protein expression and cleavage of IL-1β.These events were significantly suppressed by pretreatment with P2X7 rantagonist A438079.P2X7 rblockade also significantly reduced the protein expression ofα-SMA.CONCLUSION Our results suggest that the involvement of the P2X7r-NLRP3 inflammasome pathway in the secretion of IL-1βfrom extracellular ATP/LPS-stimulated human hepatic stellate cells.This study demonstrated that repression of the P2X7 rrepresents a novel potential therapeutic approach to control liver fibrosis.展开更多
P2X7 receptor （P2X7r） is important in inflammation and fibrosis. The aim of the present study was to investigate the effect of P2X7r inhibition, using a specific inhibitor （A438079） to prevent the development of l...P2X7 receptor （P2X7r） is important in inflammation and fibrosis. The aim of the present study was to investigate the effect of P2X7r inhibition, using a specific inhibitor （A438079） to prevent the development of liver fibrosis on human hepatic stellate cells, LX-2. The supernatant from lipopolysaccharide （LPS）-stimulated RAW 264.7 mouse macrophages was supplemented to LX-2 cells for 24 h. LX-2 cells were primed with LPS for 4 h and subsequently stimulated for 30 rain with 3 mmol · L^-1 of adenosine 5＇-triphosphate （ATP）. A438079 （ 10 μmol · L^-1） was supplemented to LX-2 cells 10 rain prior to ATP. Directly treated with LPS on LX-2 cells, mRNA ex- pressions of IL-1β, IL-18 and IL-6 were increased, as well as P2X7r. And caspase-1, ASC and NLRP3 mRNA ex- pressions were increased with LPS stimulation. LPS stimulation also increased oL-SMA and collagen I mRNA expres- sions. Interestingly treatment of LX-2 cells with mediums from LPS-primed RAW 264.7 mouse macrophages exhibi- ted greater increase of mRNA expressions of above genes than those in LX-2 directly treated with LPS. Pretreatment of directly or indirectly LPS-stimulated LX-2 cells with A438079 both suppressed IL-1β mRNA expression. In addi- tion treatment of LPS-primed LX-2 cells with 3 mM ATP induced the significant increase of IL-1β, IL-6, caspase- 1, pannexin-1, α-SMA and collagen I mRNA expression, the increasing of oL-SMA protein expression and cleavage of IL-1β. These events were significantly suppressed by pretreatment with P2X7r antagonist A438079. P2XTr blockade also significantly reduced the protein expression of oL-SMA. Our results suggest that the involvement of the P2X7r-NLRP3 inflammasome pathway in the secretion of IL-1β from extracellular ATP/LPS-stimulated human he- patic stellate cells. This study demonstrated that repression of the P2XTr represents a novel potential therapeutic ap- proach to control liver fibrosis.展开更多
基金supported by National Natural Science Foundation of China(81700523)
文摘OBJECTIVE To investigate the mechanism of SIRT1/AMPK signaling pathway between hepatocytes and hepatic stellate cells(HSCs).METHODS Normal human Chang liver cells and human hepatic stellate cell line,LX-2 cells were treated with SRT1720(10μmol·L^(-1))and AICAR(500μmol·L^(-1))prior to ethanol(50 mmol·L^(-1)) for 24 and 48 h.Cell viability was analyzed by methyl thiazolyl tetrazolium assay.SIRT1,AMPK and p-AMPK m RNA levels for 24 h and 48 h were analyzed by RT-PCR,SIRT1,AMPK and p-AMPK protein expressions in the supernatant at 24 and 48 h was detected by Western blot.RESULTS SRT1720 and AICAR effectively decreased LX-2 cell viabilities and exhibited scarcely little toxicity in human Chang liver cells.SRT1720 and AICAR attenuated collagen-I,α-smooth muscle actin(α-SMA)levels,activated liver kinase B-1(LKB1)and AMPK phosphorylation in ethanol treated LX-2 cells.Meanwhile,SRT1720 and AICAR enhanced SIRT1 expression mediated by ethanol both in Chang liver cells and LX-2 cells.Furthermore,SRT1720 and AICAR suppressed the expression of sterol regulatory element-binding protein-1(SREBP-1)to regulate fatty acid synthesis.CONCLUSION SIRT1 agonist and AMPK agonist blocked the crosstalk between hepatocytes and HSCs via SIRT1/AMPK signaling pathway to modulate hepatocytes accumulation of lipid and HSCs activation.
文摘OBJECTIVE The pathological characteristics of nonalcoholic steatohepatitis(NASH)include liver steatosis,inflammation,and fibrosis.Fibrosis is the most severe and significant pathological feature in NASH.Effective drug treatment could reverse early liver fibrosis and is of significance to prevent NASH from progressing into cirrhosis and liver cancer.Identification of drug targets for NASH treatment has been an active research area and is essential for the development of anti-NASH medications.Naringenin(NGN)is a flavonoid compound rich in citrus fruits.Our preliminary data demonstrated that NGN reduced diet-induced lipid accumulation and inflammation in the mouse liver,but whether NGN can attenuate liver fibrosis of NASH is not known.METHODS To study the effect of NGN on NASH fibrosis.WT mice were fed with high fat diet(HFD)and injected intraperitoneally 20%carbon tetrachloride at the same time for 8 weeks to induce NASH,and NGN was administrated by gavage in the meantime.In vitro,LO2 cells and LX2 cells were stimulated by oleic acid(OA)combined with lipopolysaccharide(LPS),respectively.RESULTS Treating the WT mice with NGN 100 mg·kg^(-1)·d-1 significantly attenuated hepatic lipid accumulation,hepatic fibrosis,plasma ALT and AST levels,inhibited protein expression of p-ERK,p-FoxO3a in the mouse livers.In vitro,on OA and LPS stimulated LO2 or LX2 cells,NGN significantly promoted apoptosis of activated hepatic stellate cells while inhibited apoptosis of hepatocytes.Mechanism study indicated that NGN inhibited MAPK pathway and promoted activation of FoxO3a,consequently promoted apoptosis of the activated LX2 cells and inhibited liver fibrosis.CONCLUSION NGN preventes NASH fibrosis via regulating MAPK/FoxO3a pathway,thus promoting apoptosis of the activated hepatic stellate cells.
基金The project supported by National Natural Science Foundation of China(81260664,81160538)
文摘OBJECTIVE To investigate the effect of P2X7receptor(P2X7r)inhibition,using a specific inhibitor(A438079)to prevent the development of liver fibrosis on human hepatic stellate cells,LX-2.METHODS The supernatant from lipopolysaccharide(LPS)-stimulated RAW264.7 mouse macrophages was supplemented to LX-2 cells for 24 h.LX-2cells were primed with LPS for 4h and subsequently stimulated for 30 min with 3mmol·L-1 of adenosine 5′-triphosphate(ATP).A438079(10μmol·L-1)was supplemented to LX-2 cells 10 min prior to ATP.RESULTS Directly treated with LPS on LX-2 cells,mRNA expressions of IL-1β,IL-18 and IL-6 were increased,as well as P2X7 r.And caspase-1,ASC and NLRP3 mRNA expressions were increased with LPS stimulation.LPS stimulation also increasedα-SMA and collagenⅠ mRNA expressions.Interestingly treatment of LX-2cells with mediums from LPS-primed RAW264.7mouse macrophages exhibited greater increase of mRNA expressions of above genes than those in LX-2directly treated with LPS.Pretreatment of directly or indirectly LPS-stimulated LX-2 cells with A438079 both suppressed IL-1βmRNA expression.In addition treatment of LPS-primed LX-2 cells with 3mmol·L-1 ATP induced the significant increase of IL-1β,IL-6,caspase-1,pannexin-1,α-SMA and collagenⅠ mRNA expression,the increasing ofα-SMA protein expression and cleavage of IL-1β.These events were significantly suppressed by pretreatment with P2X7 rantagonist A438079.P2X7 rblockade also significantly reduced the protein expression ofα-SMA.CONCLUSION Our results suggest that the involvement of the P2X7r-NLRP3 inflammasome pathway in the secretion of IL-1βfrom extracellular ATP/LPS-stimulated human hepatic stellate cells.This study demonstrated that repression of the P2X7 rrepresents a novel potential therapeutic approach to control liver fibrosis.
文摘P2X7 receptor （P2X7r） is important in inflammation and fibrosis. The aim of the present study was to investigate the effect of P2X7r inhibition, using a specific inhibitor （A438079） to prevent the development of liver fibrosis on human hepatic stellate cells, LX-2. The supernatant from lipopolysaccharide （LPS）-stimulated RAW 264.7 mouse macrophages was supplemented to LX-2 cells for 24 h. LX-2 cells were primed with LPS for 4 h and subsequently stimulated for 30 rain with 3 mmol · L^-1 of adenosine 5＇-triphosphate （ATP）. A438079 （ 10 μmol · L^-1） was supplemented to LX-2 cells 10 rain prior to ATP. Directly treated with LPS on LX-2 cells, mRNA ex- pressions of IL-1β, IL-18 and IL-6 were increased, as well as P2X7r. And caspase-1, ASC and NLRP3 mRNA ex- pressions were increased with LPS stimulation. LPS stimulation also increased oL-SMA and collagen I mRNA expres- sions. Interestingly treatment of LX-2 cells with mediums from LPS-primed RAW 264.7 mouse macrophages exhibi- ted greater increase of mRNA expressions of above genes than those in LX-2 directly treated with LPS. Pretreatment of directly or indirectly LPS-stimulated LX-2 cells with A438079 both suppressed IL-1β mRNA expression. In addi- tion treatment of LPS-primed LX-2 cells with 3 mM ATP induced the significant increase of IL-1β, IL-6, caspase- 1, pannexin-1, α-SMA and collagen I mRNA expression, the increasing of oL-SMA protein expression and cleavage of IL-1β. These events were significantly suppressed by pretreatment with P2X7r antagonist A438079. P2XTr blockade also significantly reduced the protein expression of oL-SMA. Our results suggest that the involvement of the P2X7r-NLRP3 inflammasome pathway in the secretion of IL-1β from extracellular ATP/LPS-stimulated human he- patic stellate cells. This study demonstrated that repression of the P2XTr represents a novel potential therapeutic ap- proach to control liver fibrosis.
