Oh Soo-Jin, Kim Young Yeon, Ma Ruiying, Choi Seok Tae, Choi Se Myeong, Cho Jong Hyun, Hur Ji-Yeun, Yoo Yongjin, Han Kihoon, Park Hosun, Yun Jeanho, Shin Ok Sarah
BK21 Graduate Program, Department of Biomedical Sciences, College of Medicine, Seoul, Republic of Korea.
Department of Translational Biomedical Sciences, Graduate School of Dong-A University, Busan, Republic of Korea.
Theranostics. 2025 Mar 31;15(11):4890-4908. doi: 10.7150/thno.105953. eCollection 2025.
One of the hallmarks of Alzheimer's disease (AD) is the accumulation of dysfunctional mitochondria. Herpes simplex virus type 1 (HSV1) may be a risk factor for the neuropathology linked to amyloid β (Aβ) accumulation. However, the mechanisms underlying HSV1-associated mitochondrial dysfunction in AD remain unclear. ALT001 is a novel drug that ameliorates AD-related cognitive impairment via ULK1/Rab9-mediated alternative mitophagy. In this study, we investigated the effects of ALT001 on the neurodegeneration-related microglial signatures associated with HSV1 infection. Molecular mechanisms and physiological functions of mitophagy was investigated in HSV1-infected microglia, including primary murine and human embryonic stem cell (ESC)-derived microglia (ES-MG), as well as in a microglia-neuron co-culture system. Microglial gene signatures following HSV1 infection in the presence or absence of ALT001 were analyzed using bulk RNA sequencing, and the effects of ALT001 on microglial phagocytosis and microglia-mediated immune responses were further evaluated by flow cytometry and cytokine profiles. HSV1 infection inhibited PINK1/Parkin-mediated mitophagy via HSV1-encoded protein kinase US3, resulting in mitochondrial dysfunction in both human and mouse microglia. Furthermore, transcriptomic analysis of HSV1-infected microglia revealed an upregulation of distinct microglial genes associated with disease-associated microglia (DAM)-like phenotype and pro-inflammatory activity. Pharmacological targeting of mitophagy using ALT001 prevents mitochondrial damage caused by HSV1 through ULK1/Rab9-mediated pathway. Furthermore, ALT001-induced ULK1/Rab9-dependent mitophagy restricts HSV1 infection by activating interferon-mediated antiviral immunity. Consequently, ALT001 reduces HSV1-triggered neuroinflammation, recovers HSV1-altered microglial phagocytosis for Aβ, and efficiently reverses morphological and molecular abnormalities in HSV1-infected microglia by triggering mitophagy in ES-MG. ALT001 also suppressed HSV1-mediated Aβ accumulation and neurodegeneration in the microglia-neuron co-culture and cerebral organoid model. In this study, we identified a critical molecular link between HSV1 and AD-related microglial dysfunction. Furthermore, our findings provide an evidence that therapeutic targeting of alternative mitophagy via ALT001 effectively interfere with HSV1-induced microglial dysfunction and alleviate neurodegeneration.
阿尔茨海默病（AD）的一个标志性特征是功能失调的线粒体积累。1型单纯疱疹病毒（HSV1）可能是与淀粉样β蛋白（Aβ）积累相关的神经病理学的一个风险因素。然而，AD中HSV1相关线粒体功能障碍的潜在机制仍不清楚。ALT001是一种新型药物，它通过ULK1/Rab9介导的替代性线粒体自噬改善与AD相关的认知障碍。在本研究中，我们研究了ALT001对与HSV1感染相关的神经退行性变相关小胶质细胞特征的影响。在HSV1感染的小胶质细胞中研究了线粒体自噬的分子机制和生理功能，包括原代小鼠和人胚胎干细胞（ESC）来源的小胶质细胞（ES-MG），以及在小胶质细胞-神经元共培养系统中。使用批量RNA测序分析了在有或没有ALT001的情况下HSV1感染后的小胶质细胞基因特征，并通过流式细胞术和细胞因子谱进一步评估了ALT001对小胶质细胞吞噬作用和小胶质细胞介导的免疫反应的影响。HSV1感染通过HSV1编码的蛋白激酶US3抑制PINK1/Parkin介导的线粒体自噬，导致人和小鼠小胶质细胞中的线粒体功能障碍。此外，对HSV1感染的小胶质细胞的转录组分析显示，与疾病相关小胶质细胞（DAM）样表型和促炎活性相关的不同小胶质细胞基因上调。使用ALT001对线粒体自噬进行药理学靶向可通过ULK1/Rab9介导的途径预防HSV1引起的线粒体损伤。此外，ALT001诱导的ULK1/Rab9依赖性线粒体自噬通过激活干扰素介导的抗病毒免疫来限制HSV1感染。因此，ALT001减少了HSV1引发的神经炎症，恢复了HSV1改变的小胶质细胞对Aβ的吞噬作用，并通过触发ES-MG中的线粒体自噬有效地逆转了HSV1感染的小胶质细胞中的形态和分子异常。ALT001还抑制了小胶质细胞-神经元共培养和脑类器官模型中HSV1介导的Aβ积累和神经退行性变。在本研究中，我们确定了HSV1与AD相关小胶质细胞功能障碍之间的关键分子联系。此外，我们的研究结果提供了证据，表明通过ALT001对替代性线粒体自噬进行治疗性靶向可有效干扰HSV1诱导的小胶质细胞功能障碍并减轻神经退行性变。
