Effect Of Cold Exposure On Signal Transduction In Rat Schwann Cells

Objective:Using RNA sequencing technology to examination the expression profile of rat Schwann cells under different low temperature exposure conditions,study the effect of low temperature stimulation on Schwann cell signal transduction,in order to explore the relationship between low temperature stimulation and the pathogenesis of Bell’s palsy,and provide new ideas for clinical exploration of the treatment of Bell’s palsy.Methods:Schwann cells were cultured at normal culture temperature of 37℃ and low temperature of 30℃,20℃,and 10℃ for 8 hours,respectively,and their genomes were sequenced for RNA sequencing technology.Four DEGs under different culture conditions were randomly selected,and the accuracy of RNA-seq was verified by q RT-PCR.Through topGO 2.24.0,cluster Profiler 3.0.5,Cytoscape 3.7.2 software for GO and KEGG enrichment analysis of DEGs,and PPI interaction network analysis.Results:In total,compared to the control 37°C group,1455(260 up-regulated and 1195down-regulated),2815(739 up-regulated and 2076 down-regulated)and 2514(1010up-regulated and 1504 down-regulated)differentially expressed genes were identified in 30°C group,20°C group and 10°C group.The GO enrichment analysis in 30℃ group,significant down-regulation of DEGs was mainly in CC,and significant up-regulation of DEGs was mainly in BP.Compared with 30℃ group,the DEGs in 20℃ and 10℃ group were mainly expressed on BP and CC,including membrane bound organelles,intracellular components and organelles.Ten core genes were screened using the network analysis tool cyto Hubba.The core genes in the 30°C group included Eprs,Hspa5,Gart,Mthfd1,Hspa1 a,Pdia4,Pdia5,Sod2,Dnajc3,Txndc11,the core genes in the 20°C group included Mcm5,Mcm7,Mcm4,Mcm3,Cdc6,Pcna,Mcm2,Mcm6,Rrm1,Rad51,and the core genes in the 10°C group included Mcm5,Mcm3,Mcm2,Mcm4,Cdc6,Pcna,Mcm7,Cdk2,Mcm6,Rrm1.KEGG enrichment analyses revealed that the most DEGs could be significantly enriched in signal transduction-related pathways(30℃ group:phosphatidylinositol signaling system,20℃ and 10℃ group: TNF signaling pathway).Conclusion:During cold exposure at 30°C,downregulation of ITPR1 affects the PI signaling pathway and upregulation of genes such as Hspa5 and Hyou1 affects the protein processing pathway of the endoplasmic reticulum.In addition,PMP22,TJP1,Claudin 12 and Claudin 15 related to tight junction and adhesion junction function are downregulated.The dysfunction of these pathways and genes affects nerve conduction,which may be a key factor in the occurrence of Bell’s palsy after cold exposure.The dysfunction of TNF signaling pathway associated with signal transduction in Schwann cells during cold exposure at 20°C,and a large number of Schwann cells apoptosis at10°C.It indicates that the cold exposure condition of 30°C is of more research significance in the etiological study of Bell’s palsy.Analyzing the effect of hypothermic exposure on the signal transduction mechanism of Schwann cells will help to facilitate the understanding of specific pathogenesis and provide a basis for future treatment of Bell’s palsy.