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
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 and β-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 and β-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.