Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, São Paulo, Brazil; Department of Surgery, School of Veterinary Medicine, University of São Paulo, São Paulo, São Paulo, Brazil.
Department of Pediatrics, Rady Children's Hospital San Diego, La Jolla, California; Department of Cellular and Molecular Medicine, Stem Cell Program, University of California San Diego School of Medicine, Sanford Consortium for Regenerative Medicine, La Jolla, California.
Biol Psychiatry. 2018 Apr 1;83(7):569-578. doi: 10.1016/j.biopsych.2017.09.021. Epub 2017 Oct 3.
Autism spectrum disorder (ASD) is a neurodevelopmental disorder with unclear etiology and imprecise genetic causes. The main goal of this work was to investigate neuronal connectivity and the interplay between neurons and astrocytes from individuals with nonsyndromic ASD using induced pluripotent stem cells.
Induced pluripotent stem cells were derived from a clinically well-characterized cohort of three individuals with nonsyndromic ASD sharing common behaviors and three control subjects, two clones each. We generated mixed neural cultures analyzing synaptogenesis and neuronal activity using a multielectrode array platform. Furthermore, using an enriched astrocyte population, we investigated their role in neuronal maintenance.
ASD-derived neurons had a significant decrease in synaptic gene expression and protein levels, glutamate neurotransmitter release, and, consequently, reduced spontaneous firing rate. Based on co-culture experiments, we observed that ASD-derived astrocytes interfered with proper neuronal development. In contrast, control-derived astrocytes rescued the morphological neuronal phenotype and synaptogenesis defects from ASD neuronal co-cultures. Furthermore, after identifying interleukin-6 secretion from astrocytes in individuals with ASD as a possible culprit for neural defects, we were able to increase synaptogenesis by blocking interleukin-6 levels.
Our findings reveal the contribution of astrocytes to neuronal phenotype and confirm previous studies linking interleukin-6 and autism, suggesting potential novel therapeutic pathways for a subtype of individuals with ASD. This is the first report demonstrating that glial dysfunctions could contribute to nonsyndromic autism pathophysiology using induced pluripotent stem cells modeling disease technology.
自闭症谱系障碍（ASD）是一种神经发育障碍，其病因和遗传原因尚不清楚。这项工作的主要目标是使用诱导多能干细胞研究非综合征 ASD 个体神经元连接和神经元与星形胶质细胞之间的相互作用。
从具有共同行为的三名非综合征 ASD 个体和三名对照个体中，诱导多能干细胞来源于临床特征明确的队列，每个个体有两个克隆。我们使用多电极阵列平台生成混合神经培养物，分析突触发生和神经元活动。此外，使用富含星形胶质细胞的群体，我们研究了它们在神经元维持中的作用。
ASD 来源的神经元突触基因表达和蛋白水平、谷氨酸神经递质释放显著减少，因此自发放电率降低。基于共培养实验，我们观察到 ASD 来源的星形胶质细胞干扰了正常的神经元发育。相比之下，对照来源的星形胶质细胞挽救了 ASD 神经元共培养物的形态神经元表型和突触发生缺陷。此外，在鉴定出 ASD 个体星形胶质细胞分泌的白细胞介素 6 作为神经缺陷的可能原因后，我们能够通过阻断白细胞介素 6 水平来增加突触发生。
我们的发现揭示了星形胶质细胞对神经元表型的贡献，并证实了先前将白细胞介素 6 与自闭症联系起来的研究，这表明了针对 ASD 亚类的潜在新的治疗途径。这是第一个使用诱导多能干细胞建模疾病技术报告显示胶质功能障碍可能导致非综合征自闭症病理生理学的研究。
