Sodium Valproate Regulates NE-4C Differentiation And The Repair And Regeneration Of Optic Nerve Injury In Mice

Background: Neural stem cells are a class of cells in the nervous system that are capable of self-renewal and have a diverse differentiation potential,and can differentiate into neurons,astrocytes,and oligodendrocytes under certain induced conditions.Because of their high self-renewal capacity,diverse differentiation potential,low immunogenicity,and good tissue fusion and migration function,neural stem cells can be used as a preferred vehicle for gene therapy or drug treatment,as well as for repairing a variety of central nervous system injuries or diseases.Damage to the optic nerve,an important structure in visual transmission,causes abnormalities in the transmission of visual impulses and leads to progressive loss of ganglion cells and axonal degeneration,and many retinal diseases such as glaucoma and traumatic optic nerve injury can lead to optic nerve damage,resulting in irreversible visual impairment or even blindness.However,there is no effective clinical cure for ganglion cell death caused by optic nerve injury.Aims:(1)To investigate whether sodium valproate(VPA)and sodium butyrate(SB)regulate the differentiation of neural stem cells C17.2 and NE-4C into neurons;(2)Comparison of the protective effects of VPA and SB on ganglion cells in a mouse model of optic nerve injury and whether VPA combined with overexpression of Akt enhances the regeneration of ganglion cell axons.Methods: Mouse neural stem cells C17.2 and NE-4C were first cultured in complete medium for 24 h,and then replaced with differentiation medium containing different concentrations of VPA(containing 2% fetal bovine serum and1% penicillin G-streptomycin sulphate)for 24 h,48h,72 h,4d and 5d,respectively,and RNA was extracted at the corresponding times to detect the relative growth factors and differentiation-related transcription factors The expression of growth factors and differentiation-related transcription factors was measured by RNA extraction at the corresponding times,and the morphological changes in the differentiation of neural stem cells into neurons were observed using immunofluorescent staining.Clean grade two-month-old adult mice with eyes free of lesions were included in the experiment.Six groups were randomly divided into four treatment groups:normal,injury,VPA,SB,Akt,and VPA + Akt groups,with a crush injury to the optic nerve used in both the injury and treatment groups.The retinas were harvested for the preparation of retinal cryosections,pavement sections,and optic nerve sections,which were examined by immunofluorescent staining for neuroprotection of ganglion cells and regeneration of their axons.In addition,the m RNA expression levels of neurotrophic factors and anti-apoptotic genes and the expression levels of Akt phosphorylated proteins were also examined.Results:(1)Both 3 m M SB and 1 m M VPA altered neurotrophic and transcription factor expression and cell morphology in C17.2 and NE-4C neural stem cells,but only 1 m M VPA regulated NE-4C neural stem cells into a differentiated state.(2)In optic nerve crush-injured mice,the combination of VPA and Akt overexpression not only promoted ganglion cell survival more effectively but also enhanced ganglion cell axon regeneration after optic nerve injury.Conclusion: We conclude that 1 m M VPA induces NE-4C neural stem cell differentiation and that VPA in combination with Akt enhances axonal regeneration.