The Effect of Exogenous Recombinant HMGB1 on Neural Stem Cells and Related Mechanism

Objective To explore the effect of exogenous recombinant high mobility group protein box1 （rHMGB1） on proliferation and differentiation of neural stem cells (NSCs) and the related mechanism．Methods SD rat cerebral cortex cells were cultured in serum-free medium, extending the culture and purification of neural stem cells. NSCs were identified by detecting nestin-label with immunofluorescence method.The NSCs proliferation activity after adding different concentrations of rHMGB1 was determined by CCK-8 assay and the optimal concentration of rHMGB1 for the follow-up experiments was selected.The effect of rHMGB1 on NSCs differentiation was detected by immunofluorescence assay. The mRNA and protein expression of involved factors were studied by real-time PCR and Western blot separately. Results The neural cells isolated from the cortex of rat embryos showed the expression of nestin antigen and the neural stem cells purity could reach more than 99% when cultured to the third generation. Under the stimulation of 10 ng/mL rHMGB1, neural stem cells proliferation activity were the highest, therefore, 10 ng/mL rHMGB1 was selected to treat the experimental group. The expression of TUJ1 in the experimental group was higher than that in the control group (P<0.05). Real-time PCR and Western blot confirmed rHMGB1 could improve the expression of receptor for advanced glycation end products (RAGE), Toll-like receptor 2 (TLR2), Toll-like receptor 4 (TLR4), matrix metalloproteinase 9 (MMP-9) and nerve growth factor(NGF) respectively at the level of mRNA and protein expression.Conclusion Exogenous rHMGB1 promoted rat NSCs proliferation and differentiation into neuronsin vitro by activating RAGE,TLRs,MMP-9 signaling.