Mechanism of annexin A6 promoting differentiation and development of neural progenitor cells into oligodendrocytes

Objective To explore the mechanism of annexin A6 (AnxA6) regulating neural progenitor cells (NPCs) to differentiate into oligodendrocytes (OLs). Methods AnxA6 gene knockout and AnxA6 overexpression viral vectors were constructed in freshly isolated and cultured NPCs, and then qPCR, Western blotting, immunofluorescence staining and calcium imaging in living cells were used to detect the changes of AnxA6 knockout and overexpression on the expression of transcription factors Olig2, Hes1 and Ascl1 in NPCs differentiation in vitro, to observe the dynamic changes of intracellular Ca2+, and to evaluate the effect of AnxA6 on NPC differentiation and maturation. Results Compared with the normal control group, there was no obvious positive band of AnxA6 protein in the knockdown group (P < 0.05), but the OD value of the protein band in the overexpression group was significantly increased (P < 0.01). Under the resting state of NPCs (differentiation for 1 d), the frequency and amplitude of spontaneous oscillation of intracellular calcium ions were higher than those in the control group and the knockdown group. In the NPCs cells differentiated for 3 d, the mRNA level of Olig2 was increased and those of Hes1 and Ascl1 were decreased in the AnxA6 overexpression group. The percentage of Olig2 positive cells and the immunofluorescence signal intensity of CNPase were higher than those in the control group and knockdown group, and the up-regulated expression of the myelin formation-related factor Vimentin and Fyn mRNA was also elevated (P < 0.05). Conclusion Over expression of AnxA6 not only enhances the dynamic changes of Ca2+ in NPCs at the early stage of differentiation, but also promotes the expression of directed transcription factors in OLs and accelerates the formation and myelin sheath