Effects and mechanism of adenovirus-mediated phosphatase and tension homologue deleted on chromosome ten gene on collagen deposition in rat liver fibrosis

AIM To evaluate the effects of phosphatase and tension homologue deleted on chromosome ten(PTEN) gene on collagen metabolism in hepatic fibrosis and the underlying mechanisms.METHODS rat primary hepatic stellate cells(HSCs) and human LX-2 cells were transfected with adenovirus containing c DNA constructs encoding wild-type PTEN(Ad-PTEN), PTEN mutant G129 E gene(Ad-G129E), and r NA interference constructs targeting the PTEN sequence PTEN short hairpin r NA to up-regulate and downregulate the expression of PTEN. HSCs were assayed using fluorescent microscopy, real-time polymerase chain reaction, and western blotting. Moreover, a CCl_4-induced rat hepatic fibrosis model was established to investigate the in vivo effects. Hematoxylin and eosin, and Masson's trichrome were used to assess the histological changes. The expression of collagen Ⅰ and Ⅲ was assessed using immunohistochemistry and western blot analysis.RESULTS Elevated expression of PTEN gene reduced serum levels of alanine transaminase and aspartate transaminase, decreased collagen deposition in the liver, and reduced hepatocyte necrosis. In contrast, knockdown of PTEN expression had an opposite effect, such as increased collagen deposition in the liver, and was molecularly characterized by the increased expression of matrix metalloproteinase(MMP)-13(P < 0.01) and MMP-2(P < 0.01), as well as decreased expression of the tissue inhibitor of metalloproteinase(TIMP)-1(P < 0.01) and TIMP-2(P < 0.01).CONCLUSION These data indicated that gene therapy using recombinant adenovirus encoding PTEN might be a novel way of treating hepatic fibrosis.

In vivo hepatic differentiation potential of human umbilical cord-derived mesenchymal stem cells: Therapeutic effect on liver fibrosis/cirrhosis

AIM To investigate the hepatic differentiation potential of human umbilical cord-derived mesenchymal stem cells(h UC-MSCs) and to evaluate their therapeutic effect on liver fibrosis/cirrhosis.METHODS A CCl4-induced liver fibrotic/cirrhotic rat model was used to assess the effect of h UC-MSCs. Histopathology was assessed by hematoxylin and eosin(H&E), Masson trichrome and Sirius red staining. The liver biochemical profile was measured using a Beckman Coulter analyzer. Expression analysis was performed using immunofluorescent staining, immunohistochemistry, Western blot, and real-time PCR.RESULTS We demonstrated that the infused h UC-MSCs could differentiate into hepatocytes in vivo. Functionally, the transplantation of h UC-MSCs to CCl4-treated rats improved liver transaminases and synthetic function, reduced liver histopathology and reversed hepatobiliary fibrosis. The reversal of hepatobiliary fibrosis was likely due to the reduced activation state of hepatic stellate cells, decreased collagen deposition, and enhanced extracellular matrix remodeling via the up-regulation of MMP-13 and down-regulation of TIMP-1. CONCLUSION Transplanted h UC-MSCs could differentiate into functional hepatocytes that improved both the biochemical and histopathologic changes in a CCl4-induced rat liver fibrosis model. h UC-MSCs may offer therapeutic opportunities for treating hepatobiliary diseases, including cirrhosis.