Neurodevelopmental and behavioral defects in congenital heart disease [EMX-cre RNAseq]

Hypoplastic left heart syndrome (HLHS) is a severe congenital heart disease associated with microcephaly and poor neurodevelopmental outcomes. Here we show that the Ohia HLHS mouse model, with mutations in Sap130, a chromatin modifier, and Pcdha9, a cell adhesion protein, also exhibits microcephaly associated with mitotic block and increased apoptosis leading to impaired cortical neurogenesis. Transcriptome profiling, DNA methylation, and Sap130 ChIPseq analyses all demonstrated dysregulation of genes associated with neurogenesis, cognitive impairment and autism. This involved perturbation of REST transcriptional regulation of neurogenesis, disruption of CREB signaling regulating synaptic plasticity, and defects in neurovascular coupling mediating cerebral blood flow. Adult mice harboring either the Pcdha9 mutation, which showed normal brain anatomy, or forebrain-specific Sap130 deletion via Emx1-Cre, which showed microcephaly, both demonstrated learning and memory deficits and autism-like behavior. These novel findings provide mechanistic insights indicating the adverse neurodevelopment in HLHS may involve cell autonomous/nonautonomous defects and epigenetic dysregulation. Expression profiling using RNA-seq of 6 samples collected from forebrain of Sap130 conditional KO mice (n=3 at E14.5) and their littermate controls (n=3at E14.5).左心发育不全综合征（Hypoplastic left heart syndrome, HLHS）是一种严重的先天性心脏病，常伴随小头畸形与不良神经发育结局。本研究证实，携带有染色质修饰因子Sap130和细胞黏附蛋白Pcdha9突变的Ohia HLHS小鼠模型，同样表现出小头畸形表型，伴随有丝分裂阻滞、细胞凋亡增加，进而导致皮层神经发生受损。转录组测序（RNA-seq）、DNA甲基化分析及Sap130染色质免疫共沉淀测序（ChIP-seq）结果均显示，与神经发生、认知障碍及自闭症相关的基因存在表达失调。该失调涉及REST对神经发生的转录调控紊乱、调控突触可塑性的CREB信号通路破坏，以及介导脑血流的神经血管耦合缺陷。进一步实验发现，分别携带Pcdha9突变（脑解剖结构正常）或通过Emx1-Cre实现前脑特异性Sap130敲除（表现为小头畸形）的成年小鼠，均出现学习记忆障碍与自闭症样行为。本研究的创新性发现为HLHS相关不良神经发育的机制提供了新见解，表明其可能涉及细胞自主性/非自主性缺陷与表观遗传调控异常。本研究通过对Sap130条件性敲除（KO）小鼠（n=3，E14.5）及其同窝对照小鼠（n=3，E14.5）的前脑组织进行RNA测序，共获得6份样本的表达谱数据。