Effect Of α-Klotho Protein On Propofol Induced Cognitive Dysfunction In Rats

Objective:To explore the therapeutic effect and mechanism of α-Klotho on propofol induced cognitive dysfunction in rats,and to provide theoretical basis for the application of α-Klotho in clinical practice.Methods: Fifty 28-week-old Male SD rats were selected and divided into five groups according to random number table method: Control group(Con group),propofol group(Pro group),propofol+α-Klotho protein injection group(Pro+Kl group),lipid emulsion group(Lip group),lipid emulsion+α-Klotho protein group(Lip+Kl group),10 in each group.After adaptive feeding,water maze experiment was conducted for five days,and drug experiment was conducted on the sixth day: Con group was not tested to avoid stimulation.Rats in Pro and Pro+Kl groups were continuously pumped with propofol injection for 3 hours through tail vein,and rats in Lip and Lip+Kl groups were continuously pumped with the same dose of fat emulsion for 3 hours through tail vein.The Pro+Kl and Lip+Kl groups were intraperitoneally injected with exogenous α-Klotho protein(0.01mg/kg),and the Pro and Lip groups were intraperitoneally injected with the same amount of normal saline.On the seventh day,water maze experiment was conducted again to evaluate the cognitive function of the rats after a drug experiment.At the end of the water maze experiment,5 rats in each group were randomly selected for cardiac perfusion after deep anesthesia,and hippocampal tissue sections were taken for hematoxylin-eosin(HE)staining to observe the morphological changes of hippocampal neurons.Immunohistochemical staining(IHC)was used to detect the expression level of NLRP3 protein in the hippocampus.The expression levels of α-Klotho protein and NLRP3,ACS,Caspase-1,IL-1β and IL-18 in hippocampus were detected by the WB method.The expression levels of SOD and MDA were detected by ELISA.Results:The results of water maze test in Pro and Pro+Kl groups showed that the rats presented cognitive dysfunction after propofol injection,and the neuron cells in the hippocampal tissue showed significant structural changes,with sparse and irregular cell arrangement.In addition,the expression of NLRP3 signaling pathway protein inflammatory factors(NLRP3,ACS,Caspase-1,IL-1β,IL-18)in the hippocampus of Pro and Pro+Kl groups was significantly increased,Klotho expression was down-regulated,and oxidative stress response was significantly enhanced.However,exogenous supplementation of α-Klotho could reverse the degree of cognitive dysfunction induced by propofol in rats.Although the structure of neurons in the hippocampus of Pro+Kl group was disordered and the gap increased,the changes tended to Con group,and the expression of inflammatory factors in NLRP3 signaling pathway was decreased compared with Pro group,and the oxidative stress response was decreased.The hippocampal neurons of Lip group and Lip+Kl group had no obvious abnormality,which was similar to the Con group.Conclusions: 1.Exogenous α-Klotho supplementation can significantly improve the cognitive dysfunction induced by propofol anesthesia in rats,and the mechanism is related to the inhibition of NLRP3 inflammatory signaling pathway in the hippocampal nerve center and the reduction of oxidative stress injury.2.α-Klotho has potential application value in the treatment of perioperative cognitive dysfunction in the future.