Fig. 6. Overexpressing IGF-1 with adenovirus vector relieves hepatocyte premature aging through activating the PI3K-AKT1 pathway and disrupting nuclear p53–progerin interaction.

Freshly hepatocytes, isolated from normal rats and cultured in vitro, were transfected the IGF-1 adenovirus vector to overexpress IGF-1 (called AV-IGF-1) or nontarget adenovirus vector (called AV-CTR), and then treated with H₂O₂ (200 nM) for 24 h. And then we extracted nuclear and cytoplasmic protein of rat hepatocytes, and detected their protein levels. a Representative immunoblots of PI3K, p-AKT1, AKT1, p53, progerin, and Lamin A/C in nuclei and cytoplasm of primary rat hepatocytes of six groups (CTR, H₂O₂, AV-CTR, AV-CTR + H₂O₂, AV-IGF-1 + H₂O₂, and AV-IGF-1). b Interaction of cytoplasmic p53 with AKT1 was detected by the co-IP assay. Cytoplasmic p53 of primary rat hepatocytes were individually immunoprecipitated, and p53 and AKT1 subjected to immunoblotting analysis as indicated. c Interaction of nuclear p53 with progerin was detected by the co-IP assay. Nuclear p53 of primary rat hepatocytes were individually immunoprecipitated, as well as p53 and progerin subjected to immunoblotting analysis as indicated. d SA-β-gal activity in rat hepatocytes of the four groups (AV-CTR, AV-CTR + H₂O₂, AV-IGF-1 + H₂O₂, and AV-IGF-1), was revealed by SA-β-gal staining. Scale bar: 50 μm. SA-β-gal positive cells are quantified in the graph, right. *P < 0.05 versus the AV-CTR group; ^#P < 0.05 versus the AV-CTR + H₂O₂ group