TGF-?/Smad Signaling Pathway Mediates The Stem Cell Characteristic Of Hepatic Stellate Cell During The Liver Regeneration

ObjectiveTo explore the effects of transforming growth factor beta/Smad(TGF-?/Smad)signaling pathway on mediating the stem cell feature of hepatic stellate cells after partial hepatectomyMethodsPart one: After established the mouse partial hepatectomy(PH),the regenerated liver mRNA and protein expression of TGF-? pathway of the mouse were detected by Realtime-PCR and Western blotting pre-operation(PH0)and 1,3 and 7 days after PH(PH1,PH3,PH7 respectively).Then,additional 48 mice were grouped into the inhibition group(PH+SB-431542,5mg/kg/d)and the control group(PH+corn oil).The mice were sacrificed at day 1,3 and 7 post-PH and regenerating liver remnants were obtained.Realtime-PCR and Western Blot were used for detecting the expressing variation of TGF-? signaling pathway,realtime-PCR and immunohistochemistry were used for detecting the proliferation andfibrosis.Part two: Another 36 mice were grouped into the inhibition group(PH+SB-431542,5mg/kg/d)and the control group(PH+corn oil).The mice were sacrificed at day 1,3 and 7 post-PH and regenerating liver remnants were obtained.Realtime-PCR and immunohistochemistry were used for detecting the expression of ?-SMA,DESMIN,LGR5,SOX9,CK19 and?-catenin,realtime-PCR and immunofluorescence were used for detecting the expression of GFAP,AFP,?-catenin and CYP2E1.ResultsPart one: The mRNA and protein expression of TGF-?1 and phosphorylation of SMAD2(p-SMAD2)were upregulated significantly after PH,peaked at day 3(all P<0.05)and recovered to pre-operative level at day 7;The mRNA and protein of TGF-?1 and p-SMAD2 were all decreased significantly in the inhibited group at PH3(all P<0.05),the number of Ki67 positive cells were all increased significantly in the inhibited group at PH3 and PH7(all P<0.05)and the positive area of sirius red were all decreased significantly in the inhibited group at PH1 and PH3(all P<0.05),compared to the control group.Part two: The regenerated liver mRNA expression and staining of?-SMA,DESMIN,AFP,LGR5,SOX9,CK19 and ?-catenin were all increased significantly post-PH(all P<0.05)and recovered to pre-operative level at day 7.After administrated the inhibitor of TGF-? signaling,theregenerated liver mRNA expression and staining of ?-SMA,DESMIN,AFP,LGR5,SOX9,CK19 and ?-catenin were all decreased significantly post-PH(all P<0.05).At day 3 post-PH,a population of pericentral hepatocytes,periductal cells and stellate-like cells of the hepatic sinus were stained positive for LGR5;the CK19 and SOX9 were co-stained with Desmin and ?-SMA around the periductal region,the AFP or CYP2E1 were co-stained with GFAP in liver parenchyma in control mice.ConclusionThe crosstalk between of TGF-?/Smad pathway and Wnt /?-catenin pathway might confer hepatic stellate cells progenitor features to differentiating into hepatocyte and cholangiocyte during liver regeneration.