Effect Of Isoflurane Preconditioning On The Formation Of NLRP3 Inflammasome In Diabetic Mice After Cerebral Ischemia Reperfusion Injury

BackgroundStroke is a high risk disease threatening human health,and its incidence is high,which is the leading cause of death and disability among adults in China.In patients with stroke complicated with diabetes mellitus,aseptic inflammatory response and long-term chronic inflammatory response of diabetes mellitus occur in the body,resulting in inflammatory waterfall effect that aggravates brain injury and increases the risk of prognosis of patients.Therefore,early restoration of blood supply in the ischemic area after ischemic stroke in diabetic patients and measures to reduce cerebral ischemia-reperfusion injury are crucial to the prognosis of patients.Among the nod-like Receptors(NLRs),NLRP3(NLR family pyrin domain containing three)inflammasome play an important role in the regulation of inflammatory response.Studies have shown that inflammasome is activated by various endogenous and exogenous danger signals in the body,then activating Caspase-1 can promote the release of interleukin 1(IL-1β)and interleukin 18(IL-18),causing inflammatory response in the body.NLRP3 inflammasome strongly associated with the progression of obesity,type 2 diabetes,and gout.The NLRP3 gene knockout mice were found to have less brain damage after stroke.Isoflurane has a protective effect on the brain and is a common inhaled anesthetic in clinic.Its regulation of inflammatory response may be related to the protective effect on the brain.,but the mechanism of its cerebral protective is still unclear.We speculate that isoflurane preconditioning may have a protective effect on the brain in patients with diabetes mellitus complicated with ischemic stroke.Whether NLRP3 inflammasome are involved in the process is still unclear,so it is of great significance to explore its exact mechanism for the protection of cerebral nerve function in patients with perioperative diabetes.ObjectivesTo investigate the brain protection of isoflurane and the role of NLRP3 inflammasome in diabetic patients with ischemic stroke.MethodsFirst of all,establishing the type 2 diabetes Mellitus(T2DM)mouse model,and then to give 2%isoflurane inhalation for 60 min in mice.After 24 h,Middle Cerebral Artery Occlusion(MCAO)was performed in this mice,followed by ischemia for 60min and reperfusion for 24 h.The cerebral infarction volume,neurological functional impairment score,survival rate,expression levels of NLRP3 and related genes and proteins of this model mouse in brain tissue were detected and recorded.ResultsCompared with the control group,isoflurane preconditioning reduced the cerebral infarction volume(P=0.0014),neurological impairment score(P=0.0018)and 28-day survival rate(P=0.0382)of diabetic mice after MCAO reperfusion at 24 h after surgery.The results of qPCR showed that isoflurane preconditioning down-regulated the expression levels of NLRP3 and il-1 in ischemic penumbra of diabetic mice(P=0.0175,P=0.0004).Immunofluorescence detection of protein showed that isoflurane pretreatment reduced the expression of NLRP3 in microglia(P=0.0087).ConclusionIschemic stroke increased the expression and activation of NLRP3 inflammasome in diabetic mice.Isoflurane preconditioning inhibited expression and activation of NLRP3 inflammasome in microglia after MCAO in diabetic mice,and reduced the volume of cerebral infarction,improved the neurological function after MCAO surgery.