AIM: To study the direct reprogramming method of mouse embryonic fibroblasts (MEFs) converted into induced neural stem cells (iNSCs). METHODS: Sox2-infected MEFs were cultured in NSCs culture medium for 10 d. Subsequently, repeated suspension and adherent culture were performed for 3 times for the purification of iNSCs. The iNSCs were cultured in suspension medium. Real-time PCR was used to detect the expression of neural stem cell marker genes and pluripotent marker gene. In vivo, iNSCs were microinjected into the mouse cerebral cortex. Immunofluorescence was performed to detect the expression of neural stem cell, neuron, oligodendrocyte and astrocyte markers in vitro and vivo.RESULTS: A variety of neural stem cell marker gene expression was significantly increased in iNSCs detected by real-time PCR. Immunofluorescence confirmed that iNSCs expressed nestin and differentiated into neurons, oligodendrocytes and astrocytes in vitro and vivo.CONCLUSION: Sox2 is sufficient to trigger the direct reprogramming from MEFs to iNSCs. iNSCs have the ability of self-renew and 3 differentiation potentials in vivo and vitro. iNSCs are the suitable seed cells of SCI.
Takahashi K, Yamanaka S. Induction of pluripotent stem cells from mouse embryonic and adult fibroblast cultures by defined factors[J]. Cell, 2006, 126(4):663-676.
[2]
Dimos JT, Rodolfa KT, Niakan KK, et al. Induced pluripotent stem cells generated from patients with ALS can be differentiated into motor neurons[J]. Science, 2008, 321(5893):1218-1221.
[3]
Ebert AD, Yu J, Rose FJ, et al. Induced pluripotent stem cells from a spinal muscular atrophy patient[J]. Nature, 2009, 457(7227):277-280.
[4]
Park IH, Arora N, Huo H, et al. Disease-specific induced pluripotent stem cells[J]. Cell, 2008, 134(5):877-886.
Ambasudhan R, Talantova M, Coleman R, et al. Direct reprogramming of adult human fibroblasts to functional neurons under defined conditions[J]. Cell Stem Cell, 2011, 9(2):113-118.
[7]
Caiazzo M, Dell'Anno MT, Dvoretskova E, et al. Direct generation of functional dopaminergic neurons from mouse and human fibroblasts[J]. Nature, 2011, 476(7359):224-227.
[8]
Pang ZP, Yang N, Vierbuchen T, et al. Induction of human neuronal cells by defined transcription factors[J]. Nature, 2011, 476(7359):220-223.
[9]
Qiang L, Fujita R, Yamashita T, et al. Directed conversion of Alzheimer's disease patient skin fibroblasts into functional neurons[J]. Cell, 2011, 146(3):359-371.
[10]
Han DW, Tapia N, Hermann A, et al. Direct reprogramming of fibroblasts into neural stem cells by defined factors[J]. Cell Stem Cell, 2012, 10(4):465-472.
[11]
Lujan E, Chanda S, Ahlenius H, et al. Direct conversion of mouse fibroblasts to self-renewing, tripotent neural precursor cells[J]. Proc Natl Acad Sci U S A, 2012, 109(7):2527-2532.
[12]
Ramon-Cueto A, Cordero MI, Santos-Benito FF, et al. Functional recovery of paraplegic rats and motor axon regeneration in their spinal cords by olfactory ensheathing glia[J]. Neuron, 2000, 25(2):425-435.
Brown AK, Woller SA, Moreno G, et al. Exercise therapy and recovery after SCI: evidence that shows early intervention improves recovery of function[J]. Spinal Cord, 2011, 49(5):623-628.
