MicroRNA-34a mediates ethanol-induced impairment of neural differentiation of neural crest cells by targeting autophagy-related gene 9a.

Neural crest cells (NCCs) are multipotent progenitor cells that are sensitive to ethanol and are implicated in Fetal Alcohol Spectrum Disorders (FASD). The objective of this study is to test whether ethanol exposure can inhibit the neural differentiation of NCCs by inhibiting autophagy and whether miR-34a is involved in ethanol-induced inhibition of autophagy in NCCs. We found that ethanol exposure resulted in the inhibition of neural differentiation of NCCs. Exposure to ethanol also significantly decreased autophagy in NCCs, as indicated by a decreased LC3II/I ratio and an elevated expression of p62 protein. Knockdown of p62 restored the expression of the neurogenesis genes, NF and Mash1, in ethanol-exposed NCCs, suggesting that ethanol exposure can inhibit the neural differentiation of NCCs by inhibiting autophagy. We also found that ethanol exposure resulted in a significant increase in miR-34a expression in NCCs. Inhibition of miR-34a restored the expression of Atg9a, a direct target of miR-34a and significantly decreased ethanol-induced inhibition of autophagy in NCCs. Down-regulation of miR-34a also prevented ethanol-induced inhibition of neural differentiation of NCCs. These results demonstrate that ethanol-induced inhibition of neural differentiation of NCCs is mediated by the miR-34a through targeting Atg9a.