Effects of Lactobacillus Rhamnosus GG on Activated Microglia and Tau Phosphorylation in the Hippocampus of Aged Mice Induced by Anesthesia and Surgery / 中山大学学报(医学科学版)

ABSTRACT

ObjectiveTo investigate the effects of Lactobacillus rhamnosus GG （LGG）on microglia and Tau phosphorylation in the hippocampus of aged mice induced by anesthesia and surgery. MethodsA total of thirty 18-month-old C57BL/6J mice were randomly divided into three groups： control group， anesthesia surgery group， and anesthesia surgery + LGG group （10 mice/group）. The aged mice were oral administered by NS or LGG 109 CFU 150 μL once a day for 20 days. Then anesthesia surgery group and anesthesia surgery +LGG group received anesthesia with isoflurane and exploratory laparotomy. The activation status of microglia in the hippocampus was detected by immunofluorescence staining 12 hours after surgery. IL-6 concentration changes was detected by ELISA. The expression changes of Tau protein phosphorylation site （Tau-pS202/pT205） and total Tau protein was detected by western blot. ResultsThe microglia in the hippocampus of the control group were in a resting state， and the concentration of inflammatory factor IL-6 was （82.08 ± 12.07） pg/mL in control group. Compared to the control group， the anesthesia surgery group showed microglial cell Microglia were activated， the concentration of inflammatory factors IL-6 increased significantly to （123.7±5.72） pg/mL （P=0.000）， and the expression of phosphorylated Tau-pS202/pT205 increased the hippocampus （P=0.002）. Compared to the anesthesia surgery group， the activated microglia were inhibited， the concentration of IL-6 decreased to （96.68±9.59） pg/mL （P=0.008）， and the expression of phosphorylated Tau-pS202/pT205 reduced significantly in the AS+LGG group （P=0.002）. While there were no significant changes in total Tau protein among 3 groups. ConclusionPreoperative administration of probiotic LGG can alleviate the activation of microglia， increased secretion of inflammatory factors， and increased Tau protein phosphorylation levels in the hippocampus of elderly mice caused by anesthesia surgery.