Role of SIRT1/FoxO1 signaling pathway in trilobatin-induced reduction of cerebral ischemia-reperfusion injury in rats / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the role of the SIRT1/FoxO1 signaling pathway in trilobatin-induced reduction of cerebral ischemia-reperfusion (I/R) injury in rats.Methods:Eighty clean-grade healthy male Sprague-Dawley rats, aged 6-8 weeks, weighing 230-280 g, were divided into 4 groups ( n=20 each) using a random number table method: sham operation group (group S), cerebral I/R group (group CIR), trilobatin+ cerebral I/R group (group T) and trilobatin+ cerebral I/R+ SIRT1/FoxO1 signaling pathway inhibitor EX527 group (group E). The model of focal cerebral I/R injury was established by middle cerebral artery occlusion in anesthetized animals. Trilobatin 15 mg/kg was given by gavage twice a day for 3 consecutive days starting from 3 days before ischemia in T and E groups. EX527 5 mg/kg was intraperitoneally injected before each gavage in group E. Modified Longa scoring scale was used to assess neurological function at 24 h of reperfusion, then the rats were sacrificed and whole brain tissues were obtained for determination of cerebral infarct size (using TTC staining), apoptosis rate and level of reactive oxygen species (ROS) in the hippocampus (by flow cytometry), expression of SIRT1 and acetylated FOXO1 (Ac-FOXO1) (by Western blot) and contents of superoxide dismutase (SOD) and malondialdehyde (MDA) (by enzyme-linked immunosorbent assay) and for microscopic examination of pathological changes in the hippocampal CAI area after HE staining. Results:Compared with group S, Longa score, cerebral infarct size, apoptosis rate of hippocampal neurons, and levels of ROS and MDA were significantly increased, the content of SOD was decreased, the expression of SIRT1 was down-regulated, and the expression of Ac-FOXO1 was up-regulated in group CIR ( P<0.05). Compared with group CIR, Longa score, cerebral infarct size, apoptosis rate of hippocampal neurons, and levels of ROS and MDA were significantly decreased, the content of SOD was increased, the expression of SIRT1 was up-regulated, and the expression of Ac-FOXO1 was down-regulated in group T ( P<0.05). Compared with group T, Longa score, cerebral infarct size, apoptosis rate of hippocampal neurons, and levels of ROS and MDA were significantly increased, the content of SOD was decreased, the expression of SIRT1 was down-regulated, and the expression of Ac-FOXO1 was up-regulated in group E ( P<0.05). Conclusions:Trilobatin may inhibit oxidative stress responses and neuronal apoptosis in hippocampi by activating the SIRT1/FoxO1 signaling pathway, thus alleviating cerebral I/R injury in rats.