CircUBE3B High Expression Participates in Sevoflurane-Induced Human Hippocampal Neuron Injury via Targeting miR-326 and Regulating MYD88 Expression

The clinical application of Sevoflurane (Sevo) brings about non-negligible neuron injury, leading to postoperative cognitive dysfunction (POCD). However, related pathogenesis is complex and not fully established. We aimed to disclose the role of circRNA UBE3B (circUBE3B) in neuron injury induced by Sevo. Cell viability and apoptosis were determined by CCK-8 and flow cytometry experiments. Inflammation production was monitored by ELISA. The expression of circUBE3B, miR-326, and myeloid differentiation factor 88 (MYD88) mRNA was assessed by quantitative real-time PCR (qPCR). Apoptosis-associated markers and MYD88 protein were quantified by western blot. The putative binding site between miR-326 and circUBE3B or MYD88 was verified by a dual-luciferase reporter experiment, and their binding was validated by a pull-down assay. Sevo treatment weakened cell viability and promoted cell apoptosis and inflammatory response. CircUBE3B expression was elevated in Sevo-treated neurons. Sevo-induced neuron injury was alleviated by circUBE3B downregulation but aggravated by circUBE3B overexpression. MiR-326 was targeted by circUBE3B, and miR-326 inhibition recovered neuron injury that was repressed by circUBE3B absence in Sevo-treated neurons. MiR-326 interacted with MYD88. MiR-326 enrichment attenuated Sevo-induced neuron injury, while these effects were reversed by MYD88 overexpression. CircUBE3B dysregulation was involved in Sevo-induced human hippocampal neuron injury via targeting the miR-326/MYD88 network.