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

Background. Postoperative cognitive dysfunction (POCD) is an impairment of cognition that affects postsurgery 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. Materials 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 interleu kin (IL)-1 beta, tumor necrosis factor alpha (TNF-alpha) and IL-6 were determined using enzyme-linked immunosorbent assay (ELISA). The binding between miR-124 a nd calpain small subunit 1 (Capn4) was verified with site-directed mutagenesis. The involvement of the nuclear factor kappa B (NF-kappa B) 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 neu rons 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-kappa B signaling pathway. Conclusions. Ourfindings demonstrated that miR-124 exerted its neuroprotective role against sevoflurane via targeting Capn4 and NF-kappa B signaling pathways. Our work may provide a novel and efficacious treatment for sevoflurane anesthesia-related cognitive dysfunction.