Chronic ethanol promotes the neuronal differentiation of NG108-15 cells independently of toxin-sensitive G-proteins

Iron-mediated effect of alcohol on hepatocyte differentiation in HepaRG cells

The development of alcoholic liver diseases depends on the ability of hepatocyte to proliferate and differentiate in the case of alcohol-induced injury. Our previous work showed an inhibitory effect of alcohol on hepatocyte proliferation. However, the effect of alcohol on hepatocyte differentiation has not yet been precisely characterized. In the present study, we evaluated the effect of alcohol on hepatocyte differentiation in relationship with changes of iron metabolism in HepaRG cells. This unique bipotent human cell line can differentiate into hepatocytes and biliary epithelial cells, paralleling liver development. Results showed that alcohol reduced cell viability, total protein level and enhanced hepatic enzymes leakage in differentiated HepaRG cells. Moreover, it caused cell enlargement, decreased number of hepatocyte and expression of C/EBPα as well as bile canaliculi F-actin. Alcohol increased expression of hepatic cell-specific markers and alcohol-metabolizing enzymes (ADH2, CYP2E1). This was associated with a lipid peroxidation and an iron excess expressed by an increase in total iron content, ferritin level, iron uptake as well as an overexpression of genes involved in iron transport and storage. Alcohol-induced hepatoxicity was amplified by exogenous iron via exceeding iron overload. Taken together, our data demonstrate that in differentiated hepatocytes, alcohol reduces proliferation while increasing expression of hepatic cell-specific markers. Moreover, iron overload could be one of the underlying mechanisms of effect of alcohol on the whole differentiation process of hepatocytes.

Effects of ethanol on mouse embryonic brain development and heat shock protein 73 expression

Effects of ethanol on brain development and heat shock protein 70 (HSP70) expression were investigated in mouse embryos using the whole embryo culture, mid-brain culture, and streptavidin-biotin peroxidase complex (SABC) method. In the whole embryo culture, ethanol (1, 2 and 4 mg/ml) inhibited brain development dose dependently and the most prevalent abnormality was the open cephalic neural tube. At doses of 1 and 2 mg/ml, ethanol significantly decreased constitutive HSP70 (HSP73) expression level compared to control values in embryonic brain areas. In mid-brain culture, ethanol exposure (from 1 to 16 mg/ml) during early neuroblast differentiation inhibited neuronal differentiation and proliferation. These results suggest that ethanol may affect embryonic brain development by decreasing HSP73 expression level as well as inhibiting neuronal differentiation and proliferation during the organogenic period.