The Effects Of H-IL-6 On The Proliferation, Differentiation And Migration Of Neural Stem Cells And The Research Of Its Mechanism

Our researches are focused on the effect of H-IL-6 on the proliferation, differentiation and migration of neural stem cells (NSCs) of new-born rats.Firstly, we cultured the the NSCs in serum-free medium containing basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF). The NSCs were floated as multi-cell aggregates called neurospheres. When dissociated into a single-cell suspension and replated in the medium, the neurospheres formed again after several days. Moreover, the neurospheres were Nestin positive and could differentiate to neurons and glia when seeded on poly-L-lysine coated substrate.Secondly, we found that H-IL-6 could promote the proliferation of the NSCs significantly when added in the medium, whereas IL-6, LIF and CNTF could not. Besides, the RT-PCR results indicated that H-IL-6 might modulate the key molecules in Notch signaling pathway to maintain the NSCs.Thirdly, we found that H-IL-6 could inhibit the mRNA expression of the Ngn3, Nkx2.2 and PLP/DM-20 but not GFAP, indicating that H-IL-6 could suppress the differentiation of NSCs to oligodendrocytes but not astrocytes via regulating the oligodendrocyte precursors (OLPs). Meanwhile, the mRNA expression of Olig1 and Olig2, the earliest markers of OLPs, was not affected. Furthermore, H-IL-6 could inhibit the mRNA expression of the differentiation factors neuroD and neuroD2.Fourthly, we found that H-IL-6 could suppress the cell mobilty of NSCs on the poly-L-lysine coated substrate in a dose-dependent manner, and H-IL-6 could inhibit the mRNA expression of CXCR4 but not SDFla. In addition, the mRNA expression of CXCR4 and SDFla increased rapidly when NSCs differentiated to more restricted precursors.