Derivation of preoligodendrocytes from human‐induced pluripotent stem cells through overexpression of microRNA 338

MicroRNAs (miRNAs) control gene expression at the posttranscriptional level and have a critical role in many biological processes such as oligodendrocyte differentiation. Recent studies have shown that microRNA 338 (miR‐338) is overexpressed during the oligodendrocyte development process in the central nervous system; this finding indicates a potentially important role for miR‐338 in oligodendrocyte development. To evaluate this assumption, we studied the effect of miR‐338 overexpression on promoting the differentiation of oligodendrocyte progenitor cells (OPCs), derived from human‐induced pluripotent stem cells (hiPSC), into preoligodendrocyte. hiPSCs were differentiated into OPCs after treating for 16 days with basic fibroblast growth factor (BFGF), epidermal growth factor (FGF), and platelet‐derived growth factor (PDGF)‐AA. Bipolar OPCs appeared and the expression of OPC‐related markers, including Nestin, Olig2, Sox10, PDGFRα, and A2B5 was confirmed by real‐time polymerase chain reaction (PCR) and immunofluorescence. Then, OPCs were transduced by miR‐338 expressing lentivirus or were treated with triiodothyronine (T3) for 6 days. Data obtained from real‐time PCR and immunofluorescence experiment indicated that preoligodendrocyte markers such as Sox10, O4, and MBP were expressed at higher levels in transduced cells with miR‐338 in comparison with the T3 group. So, the overexpression of miR‐338 in iPSC‐derived OPCs can promote their differentiation into preoligodendrocyte which can be used in cell therapy of myelin‐related diseases. microRNA 338 (miR‐338) represses the proliferation‐promoting factors in oligodendrocyte progenitor cells (OPCs) and drives the differentiation into oligodendrocyte. The overexpression of miR‐338 in iPSC‐derived OPCs can promote their differentiation into preoligodendrocyte which can be used in cell therapy of myelin‐related diseases.