Department of Pharmacology, Key Laboratory of Drug Targeting and Drug Delivery Systems, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
Department of Pharmacology, Key Laboratory of Drug Targeting and Drug Delivery Systems, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
Life Sci. 2018 May 1;200:56-62. doi: 10.1016/j.lfs.2018.03.027. Epub 2018 Mar 13.
Oxidative stress caused by aging aggravates neuropathological changes and cognitive deficits. Klotho, an anti-aging protein, shows an anti-oxidative effect. The aims of the present study were to determine the potential therapeutic effect of klotho in aging-related neuropathological changes and memory impairments in senescence-accelerated mouse prone-8 (SAMP8) mice, and identify the potential mechanism of these neuroprotective effects.
A lentivirus was used to deliver and sustain the expression of klotho. The lentiviral vectors were injected into the bilateral lateral ventricles of 7-month-old SAMP8 mice or age-matched SAMR1 mice. Three months later, the Y-maze alternation task and passive avoidance task were used to assess the memory deficits of the mice. In situ hybridization, immunohistochemistry, immunofluorescence, Nissl staining, quantitative real-time PCR and Western blot assays were applied in the following research.
Our results showed that 3 months after injection of the lentiviral vectors encoding the full-length klotho gene, the expression of klotho in the brain was significantly increased in 10-month-old SAMP8 mice. This treatment reduced memory deficits, neuronal loss, synaptic damage and 4-HNE levels but increased mitochondrial manganese-superoxide dismutase (Mn-SOD) and catalase (CAT) expression. Moreover, the up-regulation of klotho expression decreased Akt and Forkhead box class O1 (FoxO1) phosphorylation.
The present study provides a novel approach for klotho gene therapy and demonstrates that direct up-regulation of klotho in the brain might improve aging-related memory impairments and decrease oxidative stress. The underlying mechanism of this effect likely involves the inhibition of the Akt/FoxO1 pathway.
衰老引起的氧化应激加剧了神经病理学变化和认知功能障碍。Klotho 是一种抗衰老蛋白，具有抗氧化作用。本研究旨在确定 Klotho 在衰老相关神经病理学变化和衰老加速模型 8 号小鼠（SAMP8）记忆障碍中的潜在治疗作用，并确定这些神经保护作用的潜在机制。
使用慢病毒载体来递送和维持 Klotho 的表达。将慢病毒载体注射到 7 月龄 SAMP8 小鼠或年龄匹配的 SAMR1 小鼠双侧侧脑室中。3 个月后，使用 Y 迷宫交替任务和被动回避任务评估小鼠的记忆障碍。应用原位杂交、免疫组织化学、免疫荧光、尼氏染色、实时定量 PCR 和 Western blot 检测。
我们的结果表明，在注射全长 Klotho 基因的慢病毒载体 3 个月后，10 月龄 SAMP8 小鼠大脑中的 Klotho 表达显著增加。这种治疗方法可减轻记忆障碍、神经元丢失、突触损伤和 4-HNE 水平，但增加线粒体锰超氧化物歧化酶（Mn-SOD）和过氧化氢酶（CAT）的表达。此外，Klotho 表达的上调降低了 Akt 和叉头框 O1（FoxO1）的磷酸化。
本研究为 Klotho 基因治疗提供了一种新方法，并表明直接在大脑中上调 Klotho 可能改善与衰老相关的记忆障碍并减少氧化应激。这种作用的潜在机制可能涉及 Akt/FoxO1 通路的抑制。
