Klotho 蛋白灌胃对急性脑梗死大鼠脑缺血 再灌注损伤的改善作用及其机制.

Objective To observe the ameliorating effect of intragastric administration of Klotho protein on cerebral ischemia-reperfusion injury (CIRI) in rats with acute cerebral infarction (ACI) and to explore its mechanism. Methods Fifty SD male rats were divided into the sham operation group, model group, low-dose Klotho group, medium-dose Klotho group and high-dose Klotho group, with 10 rats in each group. CIRI models after ACI were established in the model group, low-dose Klotho group, medium-dose Klotho group and high-dose Klotho group. In the sham operation group, only carotid artery vessel separation and wound suture were performed, and carotid artery clamping was not performed. After being fed for 24 h, the rats in the low-dose, medium-dose and high-dose Klotho groups were treated with 25，50 and 100 mg/kg Klotho protein, respectively, and the rats in the model group and sham operation group were treated with equal volume of normal saline. All rats in the five groups were treated once a day, for 14 days. Longa scoring method and balance beam scoring method were used to evaluate the neurological scores of rats in each group. Cerebral tissues of rats in each group were taken after decapitation. Hematoxylin staining method was used to measure the apoptosis rate of cerebral cortex neurons of rats, and receptor-interacting protein kinase 1（RIP1) and RIP3 proteins in cerebral cortex tissues of rats were detected by Western blotting. The inflammatory mediators interleukin (IL) -1β, tumor necrosis factor (TNF) -α and IL-6 were detected by enzyme-linked immunoassay, MDA was detected by TBA, SOD was detected by enzyme-linked immunoassay, and GSH-Px was detected by ultraviolet colorimetry. Results The the neurological score and cerebral cortical neuron apoptosis rate of rats in the sham operation group were lower than those in the other groups (all P<0. 05), and those in the model group were higher than those in the other groups (all P<0. 05), and those in the high-dose Klotho group were higher than those in the low-dose Klotho group and medium-dose Klotho group (all P<0. 05), and those in the mediumdose Klotho group were higher than those in the low-dose Klotho group (all P<0. 05) . The relative expression levels of RIP1 and RIP3 proteins and the expression levels of IL-1β, TNF-α, IL-6 and MDA in the cerebral cortex of rats in the sham operation group were lower than those in the other groups, while the expression levels of SOD and GSH-Px were higher than those in the other groups (all P<0. 05) . The relative expression levels of RIP1 and RIP3 proteins and the expression levels of IL-1β, TNF-α, IL-6 and MDA in cerebral cortex of rats in the model group were higher than those in the other groups, while the expression levels of SOD and GSH-Px were lower than those in the other groups (all P<0. 05) . The relative expression levels of RIP1 and RIP3 proteins and the expression levels of IL-1β, TNF-α, IL-6 and MDA in the cerebral cortex of rats in the high-dose Klotho group were lower than those in the low-dose Klotho group and medium-dose Klotho group, while the expression levels of SOD and GSH-Px were higher than those of the low-dose and medium-dose Klotho groups (all P<0. 05) . The relative expression levels of RIP1 and RIP3 protein and the expression levels of IL-1β, TNF-α, IL-6 and MDA in cerebral cortex of rats in the medium-dose Klotho group were lower than those in the low-dose Klotho group, while the expression levels of SOD and GSH-Px were higher than those in the low-dose Klotho group (all P< 0. 05) . Conclusion Gastric administration of 100 mg/kg Klotho protein can alleviate CIRI in ACI rats, and its mechanism may be related to inhibiting the expression of RIP1 and RIP3 proteins in cerebral cortex and inhibiting the inflammatory response and oxidative stress response at the site of brain injury. [ABSTRACT FROM AUTHOR]