Effects of microRNA-10a on synapse remodeling in hippocampal neurons and neuronal cell proliferation and apoptosis through the BDNF-TrkB signaling pathway in a rat model of Alzheimer's disease

Abstract

The aim of this study was to research the effects of microRNA-10a (miR-10a) on synapse remodeling and neuronal cells in rats with Alzheimer's disease (AD) through BDNF-TrkB signaling pathway. Rat models of AD were established. The neuronal cells were allocated into blank, negative control (NC), miR-10a mimics, miR-10a inhibitors, K252a, and miR-10a inhibitors + K252a groups. Expressions of miR-10a, p38, PSD95, BDNF, cAMP-response element-binding protein (CREB), and tropomyosin receptor kinase B (TrκB) were tested using RT-qPCR and Western blotting. Neuron cell proliferation, cycle, and apoptosis were observed using Cell counting kit-8 (CCK8) assay and flow cytometry. The ultrastructure was observed under a scanning electron microscope. The miR-10a expression of AD rats increased while p38, PSD95, BDNF, CREB, and TrκB expression decreased compared with the normal rats. Dual luciferase reporter gene assay testified miR-10a targeted BDNF. The expressions of p38, PSD95, BDNF, CREB, and TrκB decreased in the miR-10a mimics and K252a groups. Compared with the blank and NC group, the miR-10a mimics and K252a groups showed inhibited cell growth rate with cells mainly rest in the G1 satge, and increased spoptosis. The miR-10a inhibitors group presented an opposite trend to the miR-10a mimics and K252a groups. The synapse was complete and abundant in the miR-10a inhibitors group while disappeared in the miR-10a mimics and K252a groups. The results indicated that miR-10a restrains synapse remodeling and neuronal cell proliferation while promoting apoptosis in AD rats via inhibiting BDNF-TrkB signaling pathway.