Mapping cis-regulatory elements in human excitatory and inhibitory neurons links psychiatric disease heritability and activity-regulated transcriptional programs. Mapping cis-regulatory elements in human excitatory and inhibitory neurons links psychiatric disease heritability and activity-regulated transcriptional programs

Genome-wide association studies (GWAS) have identified hundreds of loci associated with psychiatric diseases, yet there is a lack of understanding of disease pathophysiology. Common risk variants can shed light on the molecular mechanisms underlying these diseases; however, identifying specific causal variants remains challenging. An added complication is that most common risk variants are in non-coding regions. Their impact is likely to be restricted to particular cell types, developmental stages, or cell states. Here, we comprehensively mapped cis-regulatory elements in two defined populations of human excitatory and inhibitory neurons derived from pluripotent stem cells. Overall design: We performed CUT&RUN (cleavage under targets and release using nuclease) to measure H3K27ac profiles in human induced glutamatergic (Glu) and GABAergic (GABA) neurons derived from human pluripotent stem cells (ES and iPSCs). We exposed neurons to an elevated level of potassium chloride (KCl) to study activity-induced responses, and profiled H3K27ac at various time points after depolarization.

全基因组关联分析（Genome-wide association studies, GWAS）已鉴定出数百个与精神疾病相关的基因座，但学界目前对这类疾病的病理生理学机制仍缺乏足够认知。常见风险变异可为解析此类疾病的分子机制提供线索，但甄别特异性致病变异仍极具挑战。额外的难点在于，绝大多数常见风险变异位于非编码区域，且其功能影响大概率仅局限于特定细胞类型、发育阶段或细胞状态。
本研究对多能干细胞诱导得到的两群表型明确的人兴奋性神经元与抑制性神经元的顺式调控元件（cis-regulatory elements）进行了全面注释。
整体实验设计：我们采用CUT&RUN（cleavage under targets and release using nuclease，靶位点切割与核酸酶释放技术），检测了人多能干细胞（ES及iPSCs）诱导产生的人源诱导型谷氨酸能（Glu）与γ-氨基丁酸能（GABA）神经元中的组蛋白H3赖氨酸27乙酰化（H3K27ac）修饰谱。我们通过升高氯化钾（KCl）浓度处理神经元以探究活动诱导的应答反应，并在去极化后的多个时间点对H3K27ac修饰谱进行了分析。