Effects Of Simulated Microgravity On Jurkat Cell Cycle And Cep135 Expression And Regulation

Alteration of gravity can affect cell morphology,cycle and microgravity-sensitive gene expression.CEP 135 protein is a centromere protein that is closely related to structure and function of centrosome.Our previous study of simulated-microgravity on zebrafish embryos and zebrafish embryonic cells(ZF4)demonstrated cep 135 might be a microgravity sensitive gene.Whether cep135 has similar function and expression pattern in human cells needs further investigation.In this study,human T cell lymphoblast-like cell line Jurkat was used as material.We investigated the effects of simulated microgravity on Jurkat cell cycle and cep135 expression and regulation.Results demonstrated that simulated-microgravity could induce significant up-regulation of cep135mRNA expression level and down-regulation of protein CEP135 level.Meanwhile,the expression of hsa-miR-22a was significantly increased.Based on these results,cep135 was further identified as a direct target of hsa-miR-22 by dual-luciferase system assay.Addtionally,simulated-microgravity could result in G1-phase arrest in Jurkat cells.The underlying mechanism may due to the down-regulated CDK4/CDK6 which decreased the phosphorylation of RB.Results obtained in this study will undoubtedly provide evidence for revealing the function of cep 135 and the underlying molecular mechanism of immune system dysregulation under microgravity condition.