Pan Shichao, Wen Yuxin, Liu Zhanhong, Xu Kaina, Zhang Na, Tong Xingbo, Teng Ye, Song Xue, Tong Xu
College of Medical Technology, Qiqihar Medical University, Qiqihar 161006, China.
Department of CT/MRI, Beijing Anzhen Nanchong Hospital, Capital Medical University & Nanchong Central Hospital, Nanchong 637000, China.
Brain Res Bull. 2025 May;224:111326. doi: 10.1016/j.brainresbull.2025.111326. Epub 2025 Mar 31.
Bone marrow mesenchymal stem cells (BMSCs) have demonstrated potential in the treatment of radiation-induced brain injury (RIBI); however, the presence of the blood-brain barrier (BBB) limits their therapeutic efficacy. Additionally, the precise mechanisms behind the use of BMSCs in treating RIBI are still not well understood. This study aimed to investigate the therapeutic efficacy of mannitol and BMSCs on neuronal autophagy and their efficacy in treating RIBI.
In the study, RIBI models were first established in male Sprague-Dawley (SD) rats. Evans blue staining was performed to examine how mannitol influences BBB permeability in RIBI. We isolated BMSCs from SD rats using the whole bone marrow adherent method and assessed their adipogenic and osteogenic differentiation potential through Oil Red O and Alizarin Red S staining; flow cytometry analysis assessed cell surface markers. Prussian blue staining was employed to verify the migration of iron-labeled BMSCs into brain tissue. The rats were then divided into specific treatment groups, and model establishment followed according to experimental conditions. The body weight of the rats was measured weekly throughout the study. Cognitive function was assessed using the Morris water maze test. H&E and Nissl staining were applied to evaluate hippocampal neuronal survival. We quantified key proteins in the PI3K/AKT/mTOR signaling pathway by Western blotting, and quantified autophagy-related proteins LC3B and beclin-1 using both Western blotting and immunofluorescence.
Mannitol treatment significantly increased BBB permeability and promoted BMSCs migration. The combination of BMSCs and mannitol improved cognitive and memory functions, leading to better body weight recovery compared to the BMSCs group. H&E and Nissl staining also revealed a significant increase in neuronal survival within the combined treatment group. Furthermore, we observed through Western blot and immunofluorescence analyses that combination of BMSCs and mannitol enhanced the activation of PI3K, AKT, and mTOR through phosphorylation, while it reduced the expression levels of LC3B and beclin-1.
The combination of BMSCs and mannitol treatment significantly improved cognitive function and hippocampal neuronal survival in RIBI rats. This effect was achieved by increasing BBB permeability, facilitating BMSCs migration to the injured region, and regulating excessive autophagy through the PI3K/AKT/mTOR pathway. This combined treatment demonstrated a neuroprotective effect superior to that of BMSCs treatment alone.
骨髓间充质干细胞（BMSCs）已显示出在治疗放射性脑损伤（RIBI）方面的潜力；然而，血脑屏障（BBB）的存在限制了它们的治疗效果。此外，BMSCs用于治疗RIBI背后的确切机制仍未完全了解。本研究旨在探讨甘露醇和BMSCs对神经元自噬的治疗效果及其在治疗RIBI中的疗效。
在本研究中，首先在雄性Sprague-Dawley（SD）大鼠中建立RIBI模型。进行伊文思蓝染色以检查甘露醇如何影响RIBI中血脑屏障的通透性。我们使用全骨髓贴壁法从SD大鼠中分离出BMSCs，并通过油红O和茜素红S染色评估其成脂和成骨分化潜能；流式细胞术分析评估细胞表面标志物。采用普鲁士蓝染色来验证铁标记的BMSCs向脑组织的迁移。然后将大鼠分为特定治疗组，并根据实验条件进行模型建立。在整个研究过程中每周测量大鼠的体重。使用莫里斯水迷宫试验评估认知功能。应用苏木精-伊红（H&E）和尼氏染色来评估海马神经元的存活情况。我们通过蛋白质印迹法对PI3K/AKT/mTOR信号通路中的关键蛋白进行定量，并使用蛋白质印迹法和免疫荧光法对自噬相关蛋白LC3B和贝林1进行定量。
甘露醇治疗显著增加了血脑屏障的通透性并促进了BMSCs的迁移。与BMSCs组相比，BMSCs与甘露醇联合治疗改善了认知和记忆功能，使体重恢复得更好。H&E和尼氏染色还显示联合治疗组中神经元存活显著增加。此外，我们通过蛋白质印迹和免疫荧光分析观察到，BMSCs与甘露醇联合治疗通过磷酸化增强了PI3K、AKT和mTOR的激活，同时降低了LC3B和贝林1的表达水平。
BMSCs与甘露醇联合治疗显著改善了RIBI大鼠的认知功能和海马神经元存活。这种效果是通过增加血脑屏障通透性、促进BMSCs向损伤区域迁移以及通过PI3K/AKT/mTOR途径调节过度自噬来实现的。这种联合治疗显示出优于单独使用BMSCs治疗的神经保护作用。
