Expression of transforming growth factor β1/Smad4 signal pathway in rats with nonalcoholic fatty liver disease / 中华消化杂志

ABSTRACT

Objective To investigate the expression of transforming growth factor β1,transforming growth factor beta receptor(TBR)Ⅰ,TβR Ⅱ,Smad4 and C-Jun in rats with nonalcoholic fatty liver disease(NAFLD)and to find out the mechanisms of liver fibrosis in patients with NAFLD.Methods A total of 18 male SD rats were randomly divided into normal control group(n=9)and model group(n=9).The rats in control group were fed with normal diet,and those in model group were fed with fat-rich diet(consisted of 10%lard oil+2%cholesterol).An rats were sacrificed at the 20th week.The levels of TGFβ1,TβR Ⅰ and TβR Ⅱ mRNA were examined by RT-PCR.The expressions of TGFβ1 and Smad4 in liver tissue were detected by immunohistochemistry.The expression of C-Jun protein was detected by Western blotting.Results The NAFLD model was successfully established.The immunohistochemistry examination revealed that TGFβ1 and Smad4 were expressed weekly in control group,but strongly expressed in model group.RT-PCR showed that A values of TGFβ1,TβR Ⅰ and TβR Ⅱ mRNA were 0.46±0.12,5.z4±2.70 and 3.35±1.95,respectively,in model group,which were higher than those in control group(0.21±0.09,1.36±0.77 and 0.52±0.19,all P values＜0.01).The Western blotting results demonstrated that the expression of C-Jun protein in model group(0.93±0.41)was higher than that in control group (0.32±0.25,P=0.001).Conclusion TGFβ1/Smad4 signal pathway might be involved in the development of hepatic fibrosis in NAFLD.Blocking TGFβ1/Smad4 signal pathway will be helpful in treatment of NAFLD.