Key Laboratory of Biochemistry and Molecular Pharmacology, Department of Pharmacology, Chongqing Medical University, Chongqing, 400016, China.
Neurochem Res. 2024 Nov 22;50(1):29. doi: 10.1007/s11064-024-04266-x.
Ischemia-reperfusion is a complex brain disease involving multiple biological processes, including autophagy, oxidative stress, and mitochondria-associated apoptosis. Chaperone-mediated autophagy (CMA), a selective autophagy, is involved in the development of various neurodegenerative diseases and acute nerve injury, but its role in ischemia-reperfusion is unclear. Here, we used middle cerebral artery occlusion/reperfusion (MCAO/R) and oxygen-glucose deprivation/reoxygenation (OGD/R) models to simulate cerebral ischemic stroke in vivo and in vitro, respectively. LAMP2A (lysosome-associated membrane protein 2A), a key molecule of CMA, was dramatically downregulated in ischemia-reperfusion. Enhancement of CMA activity by LAMP2A overexpression reduced the neurological deficit, brain infarct volume, pathological features, and neuronal apoptosis of the cortex in vivo. Concomitantly, enhanced CMA activity alleviated OGD/R-induced apoptosis and mitochondrial membrane potential decline in vitro. In addition, we found that CMA inhibited the P53(Tumor protein p53) signaling pathway and reduced P53 translocation to mitochondria. The P53 activator, Nutlin-3, not only reversed the inhibitory effect of CMA on apoptosis, but also significantly weakened the protective effect of CMA on OGD/R and MCAO/R. Taken together, these results indicate that inhibition of P53-mediated mitochondria-associated apoptosis is essential for the neuroprotective effect of CMA against ischemia-reperfusion.
缺血再灌注是一种涉及多种生物学过程的复杂脑疾病，包括自噬、氧化应激和线粒体相关的细胞凋亡。伴侣介导的自噬（CMA）作为一种选择性自噬，参与了多种神经退行性疾病和急性神经损伤的发生发展，但它在缺血再灌注中的作用尚不清楚。在这里，我们使用大脑中动脉闭塞/再灌注（MCAO/R）和氧葡萄糖剥夺/再氧合（OGD/R）模型分别在体内和体外模拟脑缺血性中风。CMA 的关键分子 LAMP2A（溶酶体相关膜蛋白 2A）在缺血再灌注中显著下调。通过过表达 LAMP2A 增强 CMA 活性可减少体内皮质的神经功能缺损、脑梗死体积、病理特征和神经元凋亡。同时，增强的 CMA 活性可减轻体外 OGD/R 诱导的细胞凋亡和线粒体膜电位下降。此外，我们发现 CMA 抑制了 P53（肿瘤蛋白 p53）信号通路，并减少了 P53 向线粒体的易位。CMA 的抑制剂 Nutlin-3 不仅逆转了 CMA 对细胞凋亡的抑制作用，而且还显著减弱了 CMA 对 OGD/R 和 MCAO/R 的保护作用。综上所述，这些结果表明，抑制 P53 介导的线粒体相关细胞凋亡是 CMA 对缺血再灌注的神经保护作用的关键。
