Xie Yi, Wang Xinyue, Liu Shuai, He Ziyu, Zhang Hang, Yu Zhiyuan, Xie Minjie, Wang Wei
Department of Neurology, Tongji Hospital, Tongji Medical College (Y.X., X.W., Z.H., H.Z., Z.Y., M.X., W.W.), Huazhong University of Science and Technology, Wuhan, China.
Hubei Key Laboratory of Neural Injury and Functional Reconstruction Huazhong University of Science and Technology, Wuhan, China (Y.X., X.W., Z.H., H.Z., Z.Y., M.X., W.W.).
Stroke. 2025 Jun;56(6):1554-1568. doi: 10.1161/STROKEAHA.124.048206. Epub 2025 Mar 31.
Chronic cerebral hypoperfusion-induced white matter lesions are an important cause of vascular cognitive impairment in aging life. TGF-β1 (transforming growth factor β1) is widely recognized as a multifunctional cytokine participating in numerous pathophysiological processes in the central nervous system. In this study, we aimed to evaluate the neuroprotective potentials of TGF-β1 in ischemic white matter lesions.
A mouse model of bilateral common carotid artery stenosis was established to imitate the ischemic white matter lesions. The agonist of the TGF-β1 pathway was continuously applied via intraperitoneal injection. The Morris water maze test and gait analysis system were used to assess the cognitive and gait disorders in modeling mice. The Luxol fast blue staining, immunofluorescence, and electron microscopy were conducted to determine the severity of demyelinating lesions, microglial activation, and dysfunction of the autophagy-lysosomal pathway in microglia. Furthermore, primary cultured microglia were exposed to extracted myelin debris and TGF-β1 in vitro to explore the underlying mechanisms.
As evaluated by behavioral tests, TGF-β1 significantly alleviated the cognitive dysfunction and gait disorder in bilateral common carotid artery stenosis-modeling mice. The demyelinating lesion and remyelination process were also found to be highly improved by activation of the TGF-β1 pathway. The results of immunostaining and electron microscopy showed that TGF-β1 could ameliorate microglial activation and the dysfunction of lipid metabolism in myelin-engulfed microglia. Mechanistically, in primary cultured microglia exposed to myelin debris, administration of TGF-β1 notably mitigated the inflammatory response and accumulation of intracellular lipid droplets via promoting the lipid droplets degradation in the autophagy-lysosomal pathway, as quantified by flow cytometry, immunostaining, Western blot, etc. Yet, the application of autophagy inhibitor 3-methyladenine significantly reversed the above anti-inflammatory effects of TGF-β1.
TGF-β1 relieved cognitive deficit, demyelinating lesions, and microglia-mediated neuroinflammation in bilateral common carotid artery stenosis modeling by reducing abnormal lipid droplet accumulation and dysfunction of the autophagy-lysosomal pathway in microglia. Clinically, staged activation of the TGF-β1 pathway may become a potential target and promising treatment for ischemic white matter lesions and vascular cognitive impairment.
慢性脑灌注不足所致白质病变是老年生活中血管性认知障碍的重要原因。转化生长因子β1（TGF-β1）被广泛认为是一种参与中枢神经系统众多病理生理过程的多功能细胞因子。在本研究中，我们旨在评估TGF-β1在缺血性白质病变中的神经保护潜力。
建立双侧颈总动脉狭窄小鼠模型以模拟缺血性白质病变。通过腹腔注射持续应用TGF-β1通路激动剂。采用莫里斯水迷宫试验和步态分析系统评估建模小鼠的认知和步态障碍。进行Luxol固蓝染色、免疫荧光和电子显微镜检查，以确定脱髓鞘病变的严重程度、小胶质细胞活化以及小胶质细胞中自噬-溶酶体途径的功能障碍。此外，将原代培养的小胶质细胞在体外暴露于提取的髓鞘碎片和TGF-β1，以探究潜在机制。
通过行为测试评估，TGF-β1显著减轻了双侧颈总动脉狭窄建模小鼠的认知功能障碍和步态障碍。还发现激活TGF-β1通路可显著改善脱髓鞘病变和再髓鞘化过程。免疫染色和电子显微镜检查结果表明，TGF-β1可改善小胶质细胞活化以及吞噬髓鞘的小胶质细胞中脂质代谢的功能障碍。机制上，在暴露于髓鞘碎片的原代培养小胶质细胞中，给予TGF-β1可通过促进自噬-溶酶体途径中脂滴降解，显著减轻炎症反应和细胞内脂滴积累，这通过流式细胞术、免疫染色、蛋白质印迹等方法进行定量分析。然而，应用自噬抑制剂3-甲基腺嘌呤可显著逆转TGF-β1的上述抗炎作用。
TGF-β1通过减少小胶质细胞中异常脂滴积累和自噬-溶酶体途径功能障碍，缓解了双侧颈总动脉狭窄建模中的认知缺陷、脱髓鞘病变和小胶质细胞介导的神经炎症。临床上，分阶段激活TGF-β1通路可能成为缺血性白质病变和血管性认知障碍的潜在靶点和有前景的治疗方法。
