Intrasplenic co-transplantation of fetal hepatic progenitor cells and transforming growth factor beta 1 induced hepatic stellate cells ameliorates acute liver injury / 中国组织工程研究

ABSTRACT

BACKGROUND: Difficulty in long-time survival and continuous proliferation is the main problem for transplanted fetal hepatic progenitor cells and co-transplantation with transforming growth factor beta 1 (TGF-β1)-induced hepatic stellate cells may be a promising way to solve this scientific obstacle. OBJECTIVE: To explore the therapeutic effects of co-transplantation of fetal hepatic progenitor cells and TGF-β1-induced hepatic stellate cells on acute liver injury in mice. METHODS: Over-expression vector pHBLV-CMVIE-TGF-β1 was infected to mouse hepatic stellate cells and transfection efficiency was detected by immunocytochemistory, western blot and qRT-PCR. Hepatic progenitor cells, mHPCs-E14.5, were cultured and identified by immunofluorescence in vitro.The mouse model of acute liver injury was established by intraperitoneal injection of CCl4in combination with 2/3 partial hepatectomy, followed by mHPCs-E14.5transplantation, co-transplantation of mHPCs-E14.5and mHSCs-pHBLV-CMVIE-TGF-β1 (experimental co-transplantation group) or co-transplantation of mHPCs-E14.5and mHSCs-pHBLV-CMVIE-GFP (control co-transplantation group) for cell transplantation assay. Confocal immunofluorescence staining against CK19, ALB, a-SMA was performed to analyze the engraftment and differentiation of transplanted cells in the splenic parenchyma 14 days post-transplantation; serum alanine transferase and aspartate transferase levels were monitored using an automatic biochemistry analyzer. RESULTS AND CONCLUSION: (1) A hepatic stellate cell line that over-expressing TGF-β1 was successfully established and expression levels of TGF-β1 and α-smooth muscle actin were efficiently up-regulated in the over-expression group (P < 0.01). (2) mHPCs-E14.5expressed massive AFP and low levels of ALB and CK19,confirming that this cell line was in complete conformity with fetal hepatic progenitor cells in vitro.(3)CK19 and ALB positive cells existed in the splenic parenchyma in mHPCs-E14.5transplantation group.Highly expressed ALB but less expressed α-SMA and CK19 were observed in the control co-transplantation group, while massive CK19 and a-SMA positive cells as well as less level of ALB positive cells existed in the experimental co-transplantation group. Serum alanine transferase and aspartate transferase levels were decreased remarkably after cell transplantation, and moreover, the decrease was more obvious in the experimental co-transplantation group (P < 0.05). Overall, transplanted fetal hepatic progenitor cells engraft and differentiate into hepatocytes and cholangiocytes in the splenic parechyma successfully in vivo.Importantly,hepatic stellate cells induced by TGF-β1 promote the differentiation of fetal hepatic progenitor cells into cholangiocytes and accelerate recovery from CCl4/partial hepatectomy induced acute liver injury.