Effect of Danshao Huaxian capsule on Gremlin and bone morphogenetic protein-7 expression in hepatic fibrosis in rats

AIM:To observe the effect of Danshao Huaxian capsule(DHC)on the expression of Gremlin and bone morphogenetic protein-7(BMP-7)in the liver of hepatic fibrosis rats.METHODS:A total of 75 male Wistar rats were randomly divided into a normal control group(A),a CCl4-induced hepatic fibrosis model group(B),a natural recovery group(C),a low-dose DHC-treated group(D),and a high-dose DHC-treated group(E),with 15 rats in each group.Liver fibrosis was induced by subcutaneous injections of carbon tetrachloride(CCl4)and a highlipid/low-protein diet for 8 wk,except for the rats in group A.Then,the rats in the two DHC-treated groups were administered 0.5 and 1.0 g/kg DHC by gastrogavage once per day for 8 successive weeks,respectively.By the end of the experiment,the level of transforming growth factorβ1(TGF-β1)in the liver homogenate was determined by an enzyme-linked immunosorbent assay.The mRNA and protein expression of Gremlin and BMP-7 in the liver tissue was determined by reversetranscription polymerase chain reaction,an immunohistochemical assay,and Western blot analysis.RESULTS:Compared with group A,the level of TGF-β1and the mRNA and protein expression of Gremlin were significantly higher in group B(TGF-β1:736.30±24.40μg/g vs 284.20±18.32μg/g,P<0.01;mRNA of Gremlin:80.40±5.46 vs 49.83±4.20,P<0.01;positive protein expression rate of Gremlin:38.46%±1.70%vs 3.83%±0.88%,P<0.01;relative protein expression of Gremlin:2.81±0.24 vs 0.24±0.06,P<0.01),and the mRNA and protein expression of BMP-7was significantly lower in group B(mRNA:54.00±4.34vs 93.99±7.03,P<0.01;positive protein expression rate:28.97%±3.14%vs 58.29%±6.02,P<0.01;relative protein expression:0.48±0.31 vs 1.05±0.12,P<0.01).Compared with groups B and C,the degree of hepatic fibrosis was significantly improved,and the level of TGF-β1 and the mRNA and protein expression of Gremlin were significantly lowered in the two DHCtreated groups(TGF-β1:523.14±21.29μg/g,441.86±23.18μg/g vs 736.30±24.40μg/g,651.13±15.75μg/g,P<0.01;mRNA of Gremlin:64.86±2.83,55.82±5.39 vs 80.40±5.46,70.37±4.01,P<0.01;positive protein expression rate of Gremlin:20.78%±1.60%,17.43%±2.02%vs 38.46%±1.70%,29.50%±2.64%,P<0.01;relative protein expression of Gremlin:1.95±0.26,1.65±0.20 vs 2.81±0.24,2.22±0.63,P<0.01),and the mRNA and protein expression of BMP-7 was higher in the two DHC-treated groups(mRNA:73.52±4.56,81.78±5.38 vs 54.00±4.34,62.28±4.51,P<0.01;positive protein expression rate:41.44%±4.77%,47.49%±4.59%vs28.97%±3.14%,35.85%±3.50%,P<0.01;relative protein expression:0.71±0.06,0.81±0.07 vs 0.48±CONCLUSION:The therapeutic mechanism of DHC forhepatic fibrosis in rats may be associated with inhibitionof the expression of Gremlin and up-regulation of the expression of BMP-7.

Gasdermin D-mediated hepatocyte pyroptosis expands inflammatory responses that aggravate acute liver failure by upregulating monocyte chemotactic protein 1/CC chemokine receptor-2 to recruit macrophages

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.

Transforming growth factor beta-1 upregulates glucose transporter 1 and glycolysis through canonical and noncanonical pathways in hepatic stellate cells

BACKGROUND Hepatic stellate cells(HSCs)are the key effector cells mediating the occurrence and development of liver fibrosis,while aerobic glycolysis is an important metabolic characteristic of HSC activation.Transforming growth factor-β1(TGF-β1)induces aerobic glycolysis and is a driving factor for metabolic reprogramming.The occurrence of glycolysis depends on a high glucose uptake level.Glucose transporter 1(GLUT1)is the most widely distributed glucose transporter in the body and mainly participates in the regulation of carbohydrate metabolism,thus affecting cell proliferation and growth.However,little is known about the relationship between TGF-β1 and GLUT1 in the process of liver fibrosis and the molecular mechanism underlying the promotion of aerobic glycolysis in HSCs.AIM To investigate the mechanisms of action of GLUT1,TGF-β1 and aerobic glycolysis in the process of HSC activation during liver fibrosis.METHODS Immunohistochemical staining and immunofluorescence assays were used to examine GLUT1 expression in fibrotic liver tissue.A Seahorse extracellular flux(XF)analyzer was used to examine changes in aerobic glycolytic flux,lactate production levels and glucose consumption levels in HSCs upon TGF-β1 stimulation.The mechanism by which TGF-β1 induces GLUT1 protein expression in HSCs was further explored by inhibiting/promoting the TGF-β1/mothersagainst-decapentaplegic-homolog 2/3(Smad2/3)signaling pathway and inhibiting the p38 and phosphoinositide 3-kinase(PI3K)/AKT signaling pathways.In addition,GLUT1 expression was silenced to observe changes in the growth and proliferation of HSCs.Finally,a GLUT1 inhibitor was used to verify the in vivo effects of GLUT1 on a mouse model of liver fibrosis.RESULTS GLUT1 protein expression was increased in both mouse and human fibrotic liver tissues.In addition,immunofluorescence staining revealed colocalization of GLUT1 and alpha-smooth muscle actin proteins,indicating that GLUT1 expression was related to the development of liver fibrosis.TGF-β1 caused an increase in aerobic glycolysis in HSCs and induced GLUT1 expression in HSCs by activating the Smad,p38 MAPK and P13K/AKT signaling pathways.The p38 MAPK and Smad pathways synergistically affected the induction of GLUT1 expression.GLUT1 inhibition eliminated the effect of TGF-β1 on HSC proliferation and migration.A GLUT1 inhibitor was administered in a mouse model of liver fibrosis,and GLUT1 inhibition reduced the degree of liver inflammation and liver fibrosis.CONCLUSION TGF-β1 induces GLUT1 expression in HSCs,a process related to liver fibrosis progression.In vitro experiments revealed that TGF-β1-induced GLUT1 expression might be one of the mechanisms mediating the metabolic reprogramming of HSCs.In addition,in vivo experiments also indicated that the GLUT1 protein promotes the occurrence and development of liver fibrosis.

Focal adhesion kinase-related non-kinase ameliorates liver fibrosis by inhibiting aerobic glycolysis via the FAK/Ras/c-myc/ENO1 pathway

BACKGROUND Hepatic stellate cell(HSC)hyperactivation is a central link in liver fibrosis development.HSCs perform aerobic glycolysis to provide energy for their activation.Focal adhesion kinase(FAK)promotes aerobic glycolysis in cancer cells or fibroblasts,while FAK-related non-kinase(FRNK)inhibits FAK phosphorylation and biological functions.AIM To elucidate the effect of FRNK on liver fibrosis at the level of aerobic glycolytic metabolism in HSCs.METHODS Mouse liver fibrosis models were established by administering CCl4,and the effect of FRNK on the degree of liver fibrosis in the model was evaluated.Transforming growth factor-β1 was used to activate LX-2 cells.Tyrosine phosphorylation at position 397(pY397-FAK)was detected to identify activated FAK,and the expression of the glycolysis-related proteins monocarboxylate transporter 1(MCT-1)and enolase1(ENO1)was assessed.Bioinformatics analysis was performed to predict putative binding sites for c-myc in the ENO1 promoter region,which were validated with chromatin immunoprecipitation(ChIP)and dual luciferase reporter assays.RESULTS The pY397-FAK level was increased in human fibrotic liver tissue.FRNK knockout promoted liver fibrosis in mouse models.It also increased the activation,migration,proliferation and aerobic glycolysis of primary hepatic stellate cells(pHSCs)but inhibited pHSC apoptosis.Nevertheless,opposite trends for these phenomena were observed after exogenous FRNK treatment in LX-2 cells.Mechanistically,the FAK/Ras/c-myc/ENO1 pathway promoted aerobic glycolysis,which was inhibited by exogenous FRNK.CONCLUSION FRNK inhibits aerobic glycolysis in HSCs by inhibiting the FAK/Ras/c-myc/ENO1 pathway,thereby improving liver fibrosis.FRNK might be a potential target for liver fibrosis treatment.