ApoA-1 accelerates regeneration of small-for-size fatty liver graft after transplantation.

OBJECTIVES: Apolipoprotein A-1 (ApoA-1) is involved in regulating both lipid and energy metabolism, which may play important roles in liver regeneration, especially for the liver with steatosis. We here intended to investigate the role of ApoA-1 in regeneration of small-for-size fatty liver graft and to explore the underlying mechanism.

METHODS: The association of ApoA-1 expression with liver regeneration was studied in rat liver transplantation models using small-for-size normal graft or small-for-size fatty graft. The direct role of ApoA-1 in liver regeneration was studied in mouse hepatectomy model in vivo and hepatocytes in vitro.

RESULTS: Compared to small-for-size normal graft, decreased expression of ApoA-1 associated with delayed regeneration were detected in small-for-size fatty liver graft after transplantation. In functional study, the expression of ApoA-1 was decreased in hepatocytes with steatosis and was inversely associated with the concentration of oleic acid. The ApoA-1 administration effectively attenuated hepatocytes steatosis and accelerated hepatocytes proliferation. In mouse model, ApoA-1 treatment promoted liver regeneration at day 2 after major hepatectomy. In addition, the treatment of ApoA-1 increased the expressions of PGC-1α and its target genes Tfam, Ucp2 and SDHB.

CONCLUSIONS: ApoA-1 may accelerate regeneration of small-for-size fatty liver graft at day 2 after transplantation through regulating mitochondrial function. ApoA-1 may be the potential new therapy of promoting liver regeneration.