Fogo Garrett M, Raghunayakula Sarita, Emaus Katlynn J, Torres Torres Francisco J, Shangguan Gary, Wider Joseph M, Hüttemann Maik, Sanderson Thomas H
Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA.
Ann Romney Center for Neurologic Diseases, Department Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
Autophagy. 2025 Jul;21(7):1492-1506. doi: 10.1080/15548627.2025.2472586. Epub 2025 Mar 16.
Mitochondrial damage and dysfunction are hallmarks of neuronal injury during cerebral ischemia-reperfusion (I/R). Critical mitochondrial functions including energy production and cell signaling are perturbed during I/R, often exacerbating damage and contributing to secondary injury. The integrity of the mitochondrial proteome is essential for efficient function. Mitochondrial proteostasis is mediated by the cooperative forces of mitophagy and intramitochondrial proteolysis. The aim of this study was to elucidate the patterns of mitochondrial protein dynamics and their key regulators during an model of neuronal I/R injury. Utilizing the MitoTimer reporter, we quantified mitochondrial protein oxidation and turnover during I/R injury, highlighting a key point at 2 h reoxygenation for aged/oxidized protein turnover. This turnover was found to be mediated by both LONP1-dependent proteolysis and PRKN/parkin-dependent mitophagy. Additionally, the proteostatic response of neuronal mitochondria is influenced by both mitochondrial fusion and fission machinery. Our findings highlight the involvement of both mitophagy and intramitochondrial proteolysis in the response to I/R injury.: cKO: conditional knockout; CLPP: caseinolytic mitochondrial matrix peptidase proteolytic subunit; DIV: days ; DNM1L/DRP1: dynamin 1 like; ETC: electron transport chain; hR: hours after reoxygenation; I/R: ischemia-reperfusion; LONP1: lon peptidase 1, mitochondrial; mtUPR: mitochondrial unfolded protein response; OGD: oxygen glucose deprivation; OGD/R: oxygen glucose deprivation and reoxygenation; OPA1: OPA1 mitochondrial dynamin like GTPase; PINK1: PTEN induced kinase 1; PRKN: parkin RBR E3 ubiquitin protein ligase; ROI: region of interest; WT: wild-type.
线粒体损伤和功能障碍是脑缺血再灌注（I/R）期间神经元损伤的标志。在I/R期间，包括能量产生和细胞信号传导在内的关键线粒体功能受到干扰，常常加剧损伤并导致继发性损伤。线粒体蛋白质组的完整性对于高效功能至关重要。线粒体蛋白质稳态由线粒体自噬和线粒体内蛋白质水解的协同作用介导。本研究的目的是阐明神经元I/R损伤模型中线粒体蛋白质动态变化模式及其关键调节因子。利用MitoTimer报告基因，我们量化了I/R损伤期间线粒体蛋白质的氧化和周转，突出了再氧合2小时时衰老/氧化蛋白质周转的关键点。发现这种周转由LONP1依赖性蛋白水解和PRKN/帕金依赖性线粒体自噬介导。此外，神经元线粒体的蛋白质稳态反应受线粒体融合和裂变机制的影响。我们的研究结果突出了线粒体自噬和线粒体内蛋白质水解在对I/R损伤反应中的作用。：cKO：条件性敲除；CLPP：酪蛋白水解线粒体基质肽酶蛋白水解亚基；DIV：天；DNM1L/DRP1：动力蛋白1样；ETC：电子传递链；hR：再氧合后小时数；I/R：缺血再灌注；LONP1：线粒体lon肽酶1；mtUPR：线粒体未折叠蛋白反应；OGD：氧葡萄糖剥夺；OGD/R：氧葡萄糖剥夺和再氧合；OPA1：OPA1线粒体动力蛋白样GTP酶；PINK1：PTEN诱导激酶1；PRKN：帕金RBR E3泛素蛋白连接酶；ROI：感兴趣区域；WT：野生型。
