MicroRNA-128-3p Affects Neuronal Apoptosis and Neurobehavior in Cerebral Palsy Rats by Targeting E3 Ubiquitin-Linking Enzyme Smurf2 and Regulating YY1 Expression.

ABSTRACT

This study was dedicated to investigating the effects of microRNA-128-3p (miR-128-3p) on neuronal apoptosis and neurobehavior in cerebral palsy (CP) rats via the Smurf2/YY1 axis.In vivo modeling of hypoxic-ischemic (HI) CP was established in neonatal rats. Neurobehavioral tests (geotaxis reflex, cliff avoidance reaction, and grip test) were measured after HI induction. The HI-induced neurological injury was evaluated by HE staining, Nissl staining, TUNEL staining, immunohistochemical staining, and RT-qPCR. The expression of miR-128-3p, Smurf2, and YY1 was determined by RT-qPCR and western blot techniques. Moreover, primary cortical neurons were used to establish the oxygen and glucose deprivation (OGD) model in vitro, cell viability was detected by CCK-8 assay, neuronal apoptosis was assessed by flow cytometry and western blot, and the underlying mechanism between miR-128-3p, Smurf2 and YY1 was verified by bioinformatics analysis, dual luciferase reporter assay, RIP, Co-IP, ubiquitination assay, western blot, and RT-qPCR.In vivo, miR-128-3p and YY1 expression was elevated, and Smurf2 expression was decreased in brain tissues of hypoxic-ischemic CP rats. Downregulation of miR-128-3p or overexpression of Smurf2 improved neurobehavioral performance, reduced neuronal apoptosis, and elevated Nestin and NGF expression in hypoxic-ischemic CP rats, and downregulation of Smurf2 reversed the effects of downregulation of miR-128-3p on neurobehavioral performance, neuronal apoptosis, and Nestin and NGF expression in hypoxic-ischemic CP rats, while overexpression of YY1 reversed the effects of Smurf2 on neurobehavioral performance, neuronal apoptosis, and Nestin and NGF expression in hypoxic-ischemic CP rats. In vitro, downregulation of miR-128-3p effectively promoted the neuronal survival, reduced the apoptosis rate, and decreased caspase3 protein expression after OGD, and overexpression of YY1 reversed the ameliorative effect of downregulation of miR-128-3p on OGD-induced neuronal injury. miR-128-3p targeted to suppress Smurf2 to lower YY1 ubiquitination degradation and decrease its expression.Inhibition of miR-128-3p improves neuronal apoptosis and neurobehavioral changes in hypoxic-ischemic CP rats by promoting Smurf2 to promote YY1 ubiquitination degradation and reduce YY1 expression.