Role of miR-124 in the regulation of retinoic acid-induced Neuro-2A cell differentiation

Retinoic acid can cause many types of cells,including mouse neuroblastoma Neuro-2 A cells,to differentiate into neurons.However,it is still unknown whether microRNAs(miRNAs)play a role in this neuronal differentiation.To address this issue,real-time polymerase chain reaction assays were used to detect the expression of several differentiation-related miRNAs during the differentiation of retinoic acid-treated Neuro-2 A cells.The results revealed that miR-124 and miR-9 were upregulated,while miR-125 b was downregulated in retinoic acid-treated Neuro-2 A cells.To identify the miRNA that may play a key role,miR-124 expression was regulated by transfection of miRNA mimics or inhibitors.Morphological analysis results showed that inhibition of miR-124 expression reversed the effects of retinoic acid on neurite outgrowth.Moreover,miR-124 overexpression alone caused Neuro-2 A cells to differentiate into neurons,and its inhibitor could block this effect.These results suggest that miR-124 plays an important role in retinoic acid-induced differentiation of Neuro-2 A cells.