We have established human-induced pluripotent stem cell lines from healthy donors and multiple liver disease patients (13–15, 18). Using our stepwise hepatic differentiation protocol, iPSCs can be induced to definite endoderm (DE), hepatic progenitor cells (HP), and then mature hepatocyte-like cells (MH) under defined conditions (13–15, 17). This in vitro process has been designed to recapitulate human liver development. Here we exposed different stages of iPSC-induced hepatic cells to alcohol (ethanol) at a pathophysiological concentration (100 mM) (19). We observe that exposure to ethanol at the pathophysiological dosage significantly reduces the expression of AFP, an early hepatic cell marker, and induces cell apoptosis, during differentiation of iPSC-derived endoderm into hepatic progenitor cells. Proliferative activity of more mature stage hepatic cells is significantly lowered. Increased amounts of lipid droplets are detected in ethanol-treated iPSC-derived hepatocytes compared to controls.
