New methods for investigating human astrocytes are urgently needed, given their critical role in the central nervous system. Here we show that CD49f is a novel marker for human astrocytes, expressed in fetal and adult brains from healthy and diseased individuals. CD49f can be used to purify fetal astrocytes and human induced pluripotent stem cell (hiPSC)-derived astrocytes. We provide single-cell and bulk transcriptome analyses of CD49f⁺ hiPSC-astrocytes and demonstrate that they perform key astrocytic functions in vitro, including trophic support of neurons, glutamate uptake, and phagocytosis. Notably, CD49f⁺ hiPSC-astrocytes respond to inflammatory stimuli, acquiring an A1-like reactive state, in which they display impaired phagocytosis and glutamate uptake and fail to support neuronal maturation. Most importantly, we show that conditioned medium from human reactive A1-like astrocytes is toxic to human and rodent neurons. CD49f⁺ hiPSC-astrocytes are thus a valuable resource for investigating human astrocyte function and dysfunction in health and disease.

鉴于星形胶质细胞在中枢神经系统中的关键作用，迫切需要研究人类星形胶质细胞的新方法。在这里，我们表明 CD49f 是人类星形胶质细胞的新型标记物，在健康和患病个体的胎儿和成人大脑中表达。CD49f 可用于纯化胎儿星形胶质细胞和人诱导多能干细胞 (hiPSC) 衍生的星形胶质细胞。我们提供 CD49f ⁺ hiPSC-星形胶质细胞的单细胞和批量转录组分析，并证明它们在体外执行关键的星形胶质细胞功能，包括神经元的营养支持、谷氨酸摄取和吞噬作用。值得注意的是，CD49f ⁺hiPSC-星形胶质细胞对炎症刺激做出反应，获得 A1 样反应状态，在这种状态下，它们显示出吞噬作用和谷氨酸摄取受损，无法支持神经元成熟。最重要的是，我们表明来自人类反应性 A1 样星形胶质细胞的条件培养基对人类和啮齿动物神经元有毒。CD49f ⁺ hiPSC-星形胶质细胞因此是研究人类星形胶质细胞功能和健康和疾病功能障碍的宝贵资源。