Wu Jiaxiang, Chen Xiaoling, Zhang Jingliang, Wettschurack Kyle, Robinson Morgan, Li Weihao, Zhao Yuanrui, Yoo Ye-Eun, Deming Brody A, Abeyaratna Akila D, Que Zhefu, Du Dongshu, Tegtmeyer Matthew, Yuan Chongli, Skarnes William C, Rochet Jean-Christophe, Wu Long-Jun, Yang Yang
Borch Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA.
Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, USA.
bioRxiv. 2025 Jun 4:2025.06.04.657874. doi: 10.1101/2025.06.04.657874.
Microglia critically shape neuronal circuit development and function, yet their region-specific properties and roles in distinct circuits of the human brain remain poorly understood. In this study, we generated region-specific brain organoids (cortical, striatal, and midbrain), each integrated with human microglia, to fill this critical gap. Single-cell RNA sequencing uncovered six distinct microglial subtypes exhibiting unique regional signatures, including a subtype highly enriched for the GABA receptor gene within striatal organoids. To investigate the contributions of microglia to neural circuitry, we created microglia-incorporated midbrain-striatal assembloids, modeling a core circuit node for many neuropsychiatric disorders including autism. Using chemogenetics to activate this midbrain-striatal circuit, we observed increased calcium signaling in microglia involving GABA receptors. Leveraging this model, we examined microglial responses within neural circuits harboring an nonsense (C959X) mutation associated with profound autism. Remarkably, microglia displayed heightened calcium responses to mutation-mediated neuronal hyperactivity, and engaged in excessive synaptic pruning. These pathological effects were reversed by pharmacological inhibition of microglial GABA receptors. Collectively, our findings establish an advanced platform to dissect human neuroimmune interactions in sub-cortical regions, highlighting the important role of microglia in shaping critical circuitry related to neuropsychiatric disorders.
小胶质细胞对神经元回路的发育和功能起着关键作用，然而它们在人类大脑不同回路中的区域特异性特性和作用仍知之甚少。在本研究中，我们生成了与人类小胶质细胞整合的区域特异性脑类器官（皮质、纹状体和中脑），以填补这一关键空白。单细胞RNA测序揭示了六种不同的小胶质细胞亚型，它们表现出独特的区域特征，包括在纹状体类器官中高度富集GABA受体基因的一种亚型。为了研究小胶质细胞对神经回路的贡献，我们创建了包含小胶质细胞的中脑 - 纹状体组装体，模拟包括自闭症在内的许多神经精神疾病的核心回路节点。使用化学遗传学激活这个中脑 - 纹状体回路，我们观察到涉及GABA受体的小胶质细胞中钙信号增加。利用这个模型，我们检查了在携带与严重自闭症相关的无义（C959X）突变的神经回路中小胶质细胞的反应。值得注意的是，小胶质细胞对突变介导的神经元过度活跃表现出增强的钙反应，并参与了过度的突触修剪。这些病理效应通过对小胶质细胞GABA受体的药理学抑制得以逆转。总的来说，我们的研究结果建立了一个先进的平台来剖析人类皮质下区域的神经免疫相互作用，突出了小胶质细胞在塑造与神经精神疾病相关的关键回路中的重要作用。
