【摘要】 目的 探究Klotho蛋白调节半胱氨酸蛋白酶-8(Caspase-8)/Caspase-3表达对缺氧缺血性脑损伤(HIBD)大鼠神经细胞凋亡的保护作用。方法 SPF级C57BL/6新生大鼠75只，60只用于构建HIBD大鼠模型，并将其分为模型组和Klotho低、中、高剂量组，另取15只新生大鼠作为假手术组。Klotho低、中、高剂量组分别用10、20、30 mg/kg的Klotho蛋白持续脑室注射处理5 d,假手术组和模型组用同等体积生理盐水处理。对比各组脑室注射处理后神经功能、神经细胞凋亡率、脑组织中Caspase-8、 Caspase-3和氧化应激指标。结果 与假手术组相比，模型组大鼠Longa法评分和神经细胞凋亡率明显增加，大脑皮层组织中Caspase-8、 Caspase-3、活性氧(ROS)和丙二醛(MDA)水平明显升高，超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活性明显下降(均P<0.05)。与模型组相比，Klotho低、中、高剂量组Longa法评分、神经细胞凋亡率和大脑皮层组织中Caspase-8、Caspase-3、ROS、MDA水平均明显下降，SOD和GSH-Px活性均明显升高(均P<0.05)。与Klotho低剂量组相比，Klotho中、高剂量组的Longa法评分、神经细胞凋亡率和大脑皮层组织中Caspase-8、 Caspase-3、ROS、MDA水平均明显下降，SOD和GSH-Px活性均明显升高(均P<0.05)。与Klotho中剂量组相比，Klotho高剂量组的Longa法评分、神经细胞凋亡率和大脑皮层组织中Caspase-8、 Caspase-3、ROS、MDA水平均明显下降，SOD和GSH-Px活性均明显升高(均P<0.05)。结论 30 mg/kg的Klotho蛋白能有效抑制HIBD大鼠神经细胞凋亡，改善大鼠神经功能，其机制可能与抑制大鼠脑组织Caspase-8/Caspase-3表达，降低脑组织氧化应激损伤有关。更多还原

【Abstract】 Objective To explore the protective effect of Klotho protein regulating the expression of cysteine protease-8(Caspase-8)/Caspase-3 on neuronal apoptosis in rats with hypoxic-ischemic brain injury(HIBD). Methods A total of 60 HIBD rat models were constructed and divided into the model group and the low-dose, medium-dose, and high-dose Klotho groups, and another 15 neonatal rats were selected as the sham operation group. The low-dose, medium-dose and high-dose Klotho groups were treated with continuous ventricular injection of 10, 20 and 30mg/kg of Klotho protein for 5 days respectively, while the sham operation group and the model group were treated with the same volume of normal saline. The neurological function, apoptosis rate of nerve cells, Caspase-8, Caspase-3 and oxidative stress indicators in brain tissue of each group were compared after ventricular injection treatment. Results Compared with the sham operation group, the Longa method score and the apoptosis rate of nerve cells in the model group were significantly increased, and the levels of Caspase-8, Caspase-3, reactive oxygen species(ROS), and malondialdehyde(MDA) in the brain tissue were significantly elevated, and the activities of superoxide dismutase(SOD) and glutathione peroxidase(GSH-Px) decreased significantly(all P < 0.05). Compared with the model group, the Longa score, the apoptosis rate of nerve cells, and the levels of Caspase-8, Caspase-3, ROS and MDA in brain tissue all decreased significantly the Klotho protein groups, and the activities of SOD and GSH-Px increased(all P < 0.05). Compared with the low-dose group of Klotho protein, the Longa method score, the apoptosis rate of nerve cells, and the levels of Caspase-8, Caspase-3, ROS, and MDA in brain tissue all decreased significantly in the medium and high-dose groups, and the activities of SOD and GSH-Px increased significantly(all P<0.05). Compared with the medium-dose group of Klotho protein, the Longa method score, the apoptosis rate of nerve cells, and the levels of Caspase-8, Caspase-3, ROS, and MDA in brain tissue all decreased significantly in the high-dose group, and the activities of SOD and GSH-Px increased significantly(all P<0.05). Conclusion The Klotho protein at a concentration of 30mg/kg can effectively inhibit the apoptosis of nerve cells in HIBD rats and improve the extension function of rats. The mechanism may be related to the inhibition of Caspase-8/Caspase-3 expression in rat brain tissue and the reduction of oxidative stress injury in brain tissue.更多还原