Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine and Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA.
Institute for Stem Cell Biology and Regenerative Medicine and Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Bioengineering, Stanford University School of Medicine, Stanford, CA 94305, USA.
Cell Stem Cell. 2019 Jul 3;25(1):103-119.e6. doi: 10.1016/j.stem.2019.04.021. Epub 2019 May 30.
Human pluripotent stem cells can be rapidly converted into functional neurons by ectopic expression of proneural transcription factors. Here we show that directly reprogrammed neurons, despite their rapid maturation kinetics, can model teratogenic mechanisms that specifically affect early neurodevelopment. We delineated distinct phases of in vitro maturation during reprogramming of human neurons and assessed the cellular phenotypes of valproic acid (VPA), a teratogenic drug. VPA exposure caused chronic impairment of dendritic morphology and functional properties of developing neurons, but not those of mature neurons. These pathogenic effects were associated with VPA-mediated inhibition of the histone deacetylase (HDAC) and glycogen synthase kinase-3 (GSK-3) pathways, which caused transcriptional downregulation of many genes, including MARCKSL1, an actin-stabilizing protein essential for dendritic morphogenesis and synapse maturation during early neurodevelopment. Our findings identify a developmentally restricted pathogenic mechanism of VPA and establish the use of reprogrammed neurons as an effective platform for modeling teratogenic pathways.
人多能干细胞可通过异位表达神经前体细胞转录因子迅速转化为功能性神经元。在这里，我们表明，尽管直接重编程的神经元具有快速成熟的动力学，但它们可以模拟特定影响早期神经发育的致畸机制。我们描述了人神经元重编程过程中的体外成熟的不同阶段，并评估了致畸药物丙戊酸（VPA）的细胞表型。VPA 暴露导致树突形态的慢性损伤和发育中神经元的功能特性，但不影响成熟神经元。这些致病作用与 VPA 介导的组蛋白去乙酰化酶（HDAC）和糖原合成酶激酶-3（GSK-3）途径的抑制有关，该抑制导致许多基因的转录下调，包括 MARCKSL1，一种肌动蛋白稳定蛋白，对早期神经发育过程中的树突形态发生和突触成熟至关重要。我们的发现确定了 VPA 的一种发育受限的致病机制，并确立了重编程神经元作为建模致畸途径的有效平台。
