Objective To investigate the neural markers’ expression in the differentiation of marrow stromal stem cells(MSCs) into neural cells. Methods Rats MSCs were expanded as undifferentiated cells in vitro for 5 to7 generations and cultured in a modified neuronal medium(MNM) after 24 hours of all-trans retinoidacid(ATRA) pretreatment. Immunocytochemistry was used to detect the expression of nestin、neuron-specific nuclear protein(NeuN)、microtubule-associated protein2 (MAP-2) and glial fibrillary acidic protein(GFAP) at different timepoints. Results After ATRA and MNM treatment, MSCs progressively assumed neuronal morphological characteristics. Nestin occurred first after 24 hours of ATRA treatment; then NeuN expressed after 2 hours of MNM treatment; the last one was MAP-2 and it was detected after 9 hours of MNM treatment. Other markers continuously expressed except that the expression of nestin peaked after 18 hours of MNM induction and remarkably decreased after 36 hours. Conclusion ATRA and MNM could promote the differentiation of MSCs into neural cells and the expression of neural-specific markers was consistent with current knowledge regarding the timepoints of markers expression in the neuronal development which provides a good model in vitro for neuronal development research.
