星形胶质细胞在肌萎缩侧索硬化症 (ALS) 的发病和进展中发挥着至关重要的作用，这是一种以中枢神经系统运动神经元 (MN) 退化为特征的致命性疾病。尽管已知 ALS 中的星形胶质细胞对 MN 具有毒性，但导致其神经毒性表型的病理变化仍知之甚少。在这项研究中，我们从超氧化物歧化酶 1 (SOD1) 中携带 ALS 相关 A4V 突变的诱导多能干细胞 (iPSC) 中产生了人星形胶质细胞，以检查早期细胞通路和网络变化。蛋白质组学分析表明，与对照星形胶质细胞相比，ALS 星形胶质细胞功能失调且具有反应性。我们发现与 ALS 病理学和先天免疫 cGAS-STING 通路相关的蛋白质水平发生了显着变化。此外，我们发现 ALS 星形胶质细胞的反应性与用肿瘤坏死因子 α (TNFα)（炎症反应中的关键细胞因子）处理的对照星形胶质细胞的反应性不同。然后，我们评估了成纤维细胞生长因子 (FGF) 2、4、16 和 18 逆转 ALS 星形胶质细胞表型的潜力。其中，FGF4 在体外成功逆转了 ALS 星形胶质细胞功能障碍和反应性。当将 FGF4 递送至 ALS 小鼠 SOD1G93A 模型的脊髓时，FGF4 降低了星形胶质细胞的反应性。然而，这不足以保护 MN 免受细胞死亡。进一步的分析表明，TNFα 消除了 FGF4 实现的反应性降低，这表明 FGF4 对 ALS 表型的完全拯救受到体内持续的复杂神经炎症过程的阻碍。总之，我们的数据表明，ALS iPSC 产生的星形胶质细胞本质上功能失调，并表现出免疫反应表型。有效针对体内星形胶质细胞功能障碍和反应性可能有助于减轻 ALS 并预防 MN 死亡。版权所有 © 2024。由 Elsevier Inc. 出版。

Astrocytes play a crucial role in the onset and progression of amyotrophic lateral sclerosis (ALS), a fatal disorder marked by the degeneration of motor neurons (MNs) in the central nervous system. Although astrocytes in ALS are known to be toxic to MNs, the pathological changes leading to their neurotoxic phenotype remain poorly understood. In this study, we generated human astrocytes from induced pluripotent stem cells (iPSCs) carrying the ALS-associated A4V mutation in superoxide dismutase 1 (SOD1) to examine early cellular pathways and network changes. Proteomic analysis revealed that ALS astrocytes are both dysfunctional and reactive compared to control astrocytes. We identified significant alterations in the levels of proteins linked to ALS pathology and the innate immune cGAS-STING pathway. Furthermore, we found that ALS astrocyte reactivity differs from that of control astrocytes treated with tumor necrosis factor alpha (TNFα), a key cytokine in inflammatory reactions. We then evaluated the potential of fibroblast growth factor (FGF) 2, 4, 16, and 18 to reverse ALS astrocyte phenotype. Among these, FGF4 successfully reversed ALS astrocyte dysfunction and reactivity in vitro. When delivered to the spinal cord of the SOD1G93A mouse model of ALS, FGF4 lowered astrocyte reactivity. However, this was not sufficient to protect MNs from cell death. Further analysis indicated that TNFα abrogated the reactivity reduction achieved by FGF4, suggesting that complete rescue of the ALS phenotype by FGF4 is hindered by ongoing complex neuroinflammatory processes in vivo. In summary, our data demonstrate that astrocytes generated from ALS iPSCs are inherently dysfunctional and exhibit an immune reactive phenotype. Effectively targeting astrocyte dysfunction and reactivity in vivo may help mitigate ALS and prevent MN death.Copyright © 2024. Published by Elsevier Inc.