Overexpression of microRNA-375 and microRNA-122 promotes the differentiation of human induced pluripotent stem cells into hepatocyte-like cells.

MicroRNAs (miRNAs) are involved in the regulation of gene expression. In this study, we evaluated the use of overexpression of microRNA-375 (miR-375) and miR-122 in differentiating the Human Induced Pluripotent Stem Cells (hiPSCs) into functional hepatocyte-like cells (HLCs) without growth factors. We also compared the differentiation by miRNAs versus growth factors. HiPSCs were divided into two main groups: 1- HiPSCs were induced using lentiviral overexpression of miR-375 to differentiate into definitive endoderm (DE) cells in seven days. Then lentiviral overexpression of miR-122 was applied to differentiate DE cells into HLCs in additional 14 days. 2- HiPSCs were differentiated into HLCs using growth factors in 21 days. DE and hepatocyte markers were investigated by qRT-PCR, immunofluorescence, secretion analysis and LDL uptake assay. In the produced cells of both groups: the expression levels of DE markers (FOXA2 and SOX17) and hepatocyte markers (albumin, CK18, and HNF4a) in comparison with the undifferentiated hiPSCs increased significantly in seven and 21 days respectively. The albumin and urea secretion and LDL uptake were also detected. These results weren't significantly different between two groups. Therefore, we demonstrated that the over expression of miR-375 and then miR-122 could differentiate hiPSCs into functional HLCs without growth factors for developing cell-based therapies.