Transforming growth-factor-β (TGF-β) inhibits albumin synthesis in normal human hepatocytes and in hepatoma HepG2 cells

We explored the effect of transforming growth factor β (TGF-β), a cytokine that appears to play a central role in inflammatory events, on albumin expression by normal adult human hepatocytes and hepatoma cells. Addition of TGF-β to primary human hepatocyte cultures resulted in a dramatic decrease in albumin accumulation and synthesis. This effect was dose-dependent, took place after a 48h incubation period and was maintained over 96h. TGF-β-decreased albumin protein levels were associated with reduced albumin mRNA content. Actin mRNA levels were concomittantly increased. Comparable qualitative effects of TGF-β were observed on human hepatoma HepG2 cells.