Isoflurane post‐conditioning contributes to anti‐apoptotic effect after cerebral ischaemia in rats through the ERK5/MEF2D signaling pathway

Abstract

The mechanisms of brain protection during ischaemic reperfusion injury induced by isoflurane (ISO) post‐conditioning are unclear. Myocyte enhancement factor 2 (MEF2D) has been shown to promote neural survival in a variety of models, in which multiple survival and death signals converge on MEF2D and modulate its activity. Here, we investigated the effect of MEF2D on the neuroprotective effects of ISO post‐conditioning on rats after cerebral ischaemia/reperfusion (I/R) injury. Rats underwent middle cerebral artery occlusion (MCAO) surgery with ischaemia for 90 minutes and reperfusion for 24‐48 hours. After MCAO, neurological status was assessed at 12, 24 and 48 hours by the Modified Neurological Severity Score (mNSS) test. The passive avoidance test (PAT) was used to assess cognition function. Histological and neuropathological evaluations were performed with HE staining and Nissl's staining, respectively. We measured the expression of MEF2D, ERK5, GFAP and caspase‐3 by immunofluorescent staining and Western blotting, and TUNEL staining to assess the severity of apoptosis in hippocampal CA1 area. We found that MEF2D was involved in nerve protection after I/R injury, and post‐treatment of ISO significantly promoted the phosphorylation of ERK5, increased MEF2D transcriptional activity, inhibited the expression of caspase‐3 and played a role of brain protection.

NRF2 activation ameliorates blood–brain barrier injury after cerebral ischemic stroke by regulating ferroptosis and inflammation

“…After giving isoflurane (2–3% oxygen) for anesthesia, each mouse was placed in the supine position 26 . A homoeothermic blanket was employed to keep a rectal temperature of 37 °C intraoperatively.…”

Isoflurane Anesthesia’s Impact on Gene Expression Patterns of Rat Brains in an Ischemic Stroke Model

“…Some authors expanded the functional understanding of ISO action by studying the far-reaching effects of dysregulated miRNA/target genes on processes such as synaptic transmission, axon development, and cell apoptosis [16]. Using immunofluorescent staining and Western blotting, we detected that ISO post-conditioning contributes to anti-apoptotic effects after cerebral ischemia in rats through the ERK5/MEF2D signaling pathway [17] and may reduce IR injury by downregulating the expression of aquaporin 4 (AQP4), possibly related to the bone morphogenetic protein 4/Smad1/5/8 signaling pathway [18].…”