MiR-124 protects against cognitive dysfunction induced by sevoflurane anesthesia in vivo and in vitro through targeting calpain small subunit 1 via NF-κB signaling pathway

Abstract

BACKGROUND: Postoperative cognitive dysfunction (POCD) is an impairment of cognition that affects post-surgery patients. Sevoflurane anesthesia is linked to cognitive dysfunction correlated to the expression of miRNA levels. OBJECTIVES: In the current study, we investigated if miR-124 can offer protection against cognitive deficits induced by sevoflurane in a spatial learning paradigm, and examined the molecular mechanisms through cell cultures. MATERIAL AND METHODS: Escape latency, platform crossings in probe trials and swimming speed in the Morris water maze in sevoflurane-treated mice were utilized as a measure of cognitive function. The relative miR-124 expression, and mRNA expressions of Bax, caspase-3 and Bcl-2 in sevoflurane-treated hippocampal cultures were measured using real-time quantitative polymerase chain reaction (RT-qPCR). Moreover, the changes in interleukin (IL)-1β, tumor necrosis factor alpha (TNF-α) and IL-6 were determined using enzyme-linked immunosorbent assay (ELISA). The binding between miR-124 and calpain small subunit 1 (Capn4) was verified with site-directed mutagenesis. The involvement of the nuclear factor kappa B (NF-κB) signaling pathway was examined using western blot analysis. RESULTS: Our findings indicated that the miR-124 expression was inhibited by sevoflurane treatment in live rats and mouse hippocampal neurons to prevent apoptosis and inflammatory responses. We confirmed Capn4 as a target of miR-124. Treatment with sevoflurane enhanced the expression of Capn4, while overexpression of miR124 suppressed the enhanced expression of Capn4. Also, miR-124 inhibited apoptosis in murine hippocampal neurons induced by sevoflurane via the NF-κB signaling pathway. CONCLUSIONS: Our findings demonstrated that miR-124 exerted its neuroprotective role against sevoflurane via targeting Capn4 and NF-κB signaling pathways. Our work may provide a novel and efficacious treatment for sevoflurane anesthesia-related cognitive dysfunction.