Islet-cell autoantigen 69 accelerates liver regeneration by downregulating Tgfbr1 and attenuating Tgfβ signaling in mice.

Regeneration is a unique defense mechanism of liver tissue in response to functional cell loss induced by toxic chemicals or surgical resection. In this study, we found that Islet-cell autoantigen 69 (Ica69) accelerates liver regeneration in mice. Following 70% partial hepatectomy, both Ica69 mRNA and protein are significantly upregulated in mouse hepatocytes at the early stage of liver regeneration. Compared with the wild-type mice, Ica69-deficient mice have more severe liver injury, delayed liver regeneration, and high surgical accidental mortality following hepatectomy. Mechanistically, Ica69 interacts with Pick1 protein to regulate Tgfbr1 protein expression and Tgfβ-induced Smad2 phosphorylation. Our findings suggest that Ica69 in liver tissue is a new potential target for promoting liver regeneration.