Studies On The Effect Of Activation Of BMP-Smad-id2 Signaling Pathway On Differentiation Of Rat Neural Stem Cells

Objectives In recent years,with the development of society,severe lethality and morbidity caused by spinal cord injury gradually increase.However,the current treatment methods for spinal cord injury are very limited and can not achieve satisfactory results.In recent years,as stem cells The rise of the research,people are more and more believe that stem cell transplantation for the treatment of spinal cord injury is a reliable strategy,However,it has been found that the BMP protein,which is highly expressed after injury,inhibits the differentiation of neurons both in vitro and in vivo and promotes the differentiation of neural stem cells into astrocytes,which inhibits the clinical application of stem cells.Therefore,the purpose of our experiment is to explore the impact of BMP protein during the process of Nscs differentiation and to explore its possible molecular mechanism,so as to better regulate the directional differentiation of stem cells.Methods Neural stem cells(NSCs)were extracted from 24-hour neonatal SD rat brain and cultured in Nscs proliferation medium.After passaged on the seventh day,the second generation of cells in good growth condition were divided into three groups;BMP4 group;BMP4 + Noggin group,We detected the expression of glial fibrillary acidic protein single(GFAP)by immunofluorescence staining and Western blot,and detected the expression of p Smad1 / 5/8 protein and its target gene Id2 protein in the BMP signaling pathway by WB.Results Seven days after differentiation,GFAP immunofluorescence staining was used to identify differentiated astrocytes in neural stem cells and protein was extracted for WB assay.We found that astrocytes in BMP4 group were significantly higher than those in Control group And GFAP protein expression increased significantly.When using the BMP receptor antagonist Noggin,compared with the BMP4 group,the expression of astrocytes in BMP4 + Noggin group was significantly decreased,while GFAP protein expression was significantly reduced,in order to explore its Molecular mechanism,we examined the expression of p Smad1 / 5/8 protein in BMP signaling pathway and its target gene Id2 protein.We found that BMP4 can activate BMP signaling pathway to upregulate p Smad1 / 5/8 While the application of Noggin could significantly reverse the activation of BMP signaling pathway.Compared with Control group,the expression of Id2 protein in BMP4 group was significantly increased.Compared with BMP4 group,the expression of Id2 protein in BMP4 + Noggin group was significantly decreased.Conclusions The results showed that BMP4 could promote the differentiation of astrocytes.BMP4 can activate the BMP signaling pathway to increase the expression of p Smad1 / 5/8,while increased p Smad1 / 5/8 upregulates the expression of its target gene Id2 protein.Therefore,we speculated that BMP4 Protein is an increase of neural stem cells differentiation,is through the activation of BMP-Smad1 / 5/8 signaling to up-regulate Id2 gene expression to achieve.The revelation of this molecular mechanism provides a good idea for the future regulation of neural stem cell differentiation experiments.