Overexpression of suppressors of cytokine signaling 1 promotes the neuronal differentiation of C17.2 neural stem cells.

OBJECTIVE To investigate the role and mechanism of suppressor of cytokine signaling 1 (SOCS1) in the regulation and differentiation of C17.2 neural stem cells (NSCs). METHODS In this study, lentiviral (LV)-SOCS1-enhanced green fluorescent protein (EGFP) was constructed and transfected into C17.2 NSCs. There were three groups of C17.2 NSCs: LV-SOCS1-EGFP, LV-EGFP, and phosphate-buffered saline (PBS). The expression levels of microtubule-associated protein 2 (MAP2), glial fibrillary acidic protein (GFAP), myelin basic protein (MBP), nestin, and β-tubulin III in C17.2 NSCs were analyzed by reverse transcription-polymerase chain reaction (RT-PCR), immunocytochemistry, and western blot. In addition, the phosphorylation level of Jaks/Stats family members in C17.2 NSCs were analyzed by western blot. Moreover, the morphological changes of C17.2 NSCs after transfection were observed by light microscopy. RESULTS The gene expression of MAP2 increased significantly and the gene expression of nestin decreased significantly in C17.2 NSCs transfected with LV-SOCS1-EGFP. Some C17.2 NSCs underwent prominent neuronal morphological changes and expressed β-tubulin III after LV-SOCS1-EGFP transfection. The number of positive cells for β-tubulin III immunocytochemical staining and β-tubulin III protein expression in C17.2 NSCs after LV-SOCS1-EGFP transfection were both more than those after LV-EGFP transfection or PBS treatment. The phosphorylation levels of Jak2 and Stat3 but not Jak3 in C17.2 NSCs were inhibited by SOCS1 overexpression. CONCLUSION Overexpression of SOCS1 in C17.2 NSCs promotes the generation of neurons, which is likely mediated by the negative feedback inhibition of Jak2 and Stat3. This study is the first to provide evidence that SOCS1 is involved in the regulation of neurogenesis.