miR-132-3p/CAMTA1对I-125粒子处理的面神经损伤大鼠施万细胞的调控作用

MiR-132-3p negatively regulates CAMTA1 to promote Schwann cell proliferation and migration and alleviates I-125 seeds-induced exacerbation of facial nerve injury in rats

目的探讨miR-132-3p通过钙调素结合转录因子1(CAMTA1)对I-125粒子处理的面神经损伤大鼠(FNI)中施万细胞的调控作用。方法用I-125粒子辐射大鼠施万细胞,并在细胞中转染miR-132-3p mimic、miR-132-3p inhibitor以及sh-CAMTA1。免疫荧光检测S100B和β-TubulinⅢ荧光强度。RT-qPCR检测miR-132-3p的表达,Western blot检测CAMTA1蛋白表达。EdU染色评估细胞增殖,Transwell检测细胞迁移。同时,构建FNI大鼠模型并在大鼠面部植入I-125粒子,HE、LFB染色以及IF染色评估大鼠面神经组织的病理损伤。StarBase v2.0数据库和双荧光素酶报告实验验证miR-132-3p和CAMTA1的靶向关系。结果S100B和β-TubulinⅢ在大鼠施万细胞中显著表达。I-125粒子辐射组中miR-132-3p表达降低(P<0.001),抑制细胞的增殖(P<0.001)和迁移(P<0.001)。过表达miR-132-3p或敲降CAMTA1显著促进施万细胞的增殖(P<0.001)和迁移(P<0.05),敲降miR-132-3p则具有相反的作用。机制研究显示,miR-132-3p靶向负调控CAMTA1。体内实验结果显示,过表达miR-132-3p通过抑制CAMTA1的蛋白表达,减弱I-125粒子对FNI大鼠面神经损伤的促进作用。结论过表达miR-132-3p抑制CAMTA1的表达,促进施万细胞的增殖和迁移,抑制I-125对FNI大鼠面神经损伤的促进作用。

Objective To investigate the regulatory effect of miR-132-3p on calmodulin-binding transcription activator 1(CAMTA1)and Schwann cell activity in rats with facial nerve injury(FNI)treated with I-125 seeds.Methods Rat Schwann cells were irradiated with I-125 seeds and transfected with miR-132-3p mimic,miR-132-3p inhibitor or sh-CAMTA1.The expressions of S100B andβ-tubulin III in the cells were detected with immunofluorescence assay,and the expressions of miR-132-3p and CAMTA1 protein were determined using RT-qPCR and Western blotting,respectively.EdU staining and Transwell assay were used to evaluate the changes in cell proliferation and migration ability.In a rat model of FNI,I-125 seeds were implanted into the facial tissues near the facial nerve 2 weeks before modeling,and miR-132-3p mimic was injected subcutaneously in the face after modeling.The pathologies of the facial nerve was assessed by HE,LFB and immunofluorescence staining.The targeting relationship between miR-132-3p and CAMTA1 was verified using StarBase v2.0 database and dual-luciferase reporter assay.Results Rat Schwann cells showed high expressions of S100B andβ-tubulin III.I-125 seeds radiation significantly decreased miR-132-3p expression and repressed proliferation and migration of the cells(P<0.001).Overexpression of miR-132-3p or CAMTA1 knockdown obviously enhanced proliferation and migration of the Schwann cells,while miR-132-3p knockdown produced the opposite effect.MiR-132-3p negatively regulated CAMTA1 expression.In the rat models of FNI,miR-132-3p injection significantly inhibited CAMTA1 expression and attenuated I-125 seeds-induced exacerbation of FNI.Conclusion Overexpression of miR-132-3p suppresses CAMTA1 expression and promotes Schwann cell proliferation and migration to alleviate I-125 seeds-induced exacerbation of FNI in rats.