Functional Loss of Semaphorin 3C and/or Semaphorin 3D and Their Epistatic Interaction with Ret Are Critical to Hirschsprung Disease Liability
Functional Loss of Semaphorin 3C and/or Semaphorin 3D and Their Epistatic Interaction with Ret Are Critical to Hirschsprung Disease Liability
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Semaphorin 3C 和/或 Semaphorin 3D 的功能丧失及其与 Ret 的上位相互作用对于先天性巨结肠疾病的发生至关重要
DOI：
10.1016/j.ajhg.2015.02.014
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发表时间：
2015-04-02
影响因子：
9.8
通讯作者：
Chakravarti, Aravinda
中科院分区：
文献类型：
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作者：
Jiang, Qian;Arnold, Stacey;Chakravarti, Aravinda
先天性巨结肠（HSCR）是肠神经元细胞分化、增殖、迁移或存活中的细胞自主和非自主缺陷的结果，肠神经支配在肠段性丧失。已知13个基因中的罕见的、高突变率的编码变体和常见的、低突变率的非编码变体是HSCR风险的基础，其中ret原癌基因（RET）中的变体最常见。我们使用了全基因组关联（220 trios）和复制（429 trios）研究，揭示了RET远端的第二个非编码变体和3类脑信号蛋白基因簇内7号染色体上的非编码等位基因。在Ret野生型和Ret缺失小鼠中的分析证明了Sema 3a、Sema 3c和Sema 3d在肠神经系统（ENS）中的特异性表达。在斑马鱼胚胎中，sema 3敲除显示迁移ENS前体减少，在联合ret功能丧失下完全消融。Sema 3蛋白的7个候选受体也在小鼠ENS内表达，并且它们的表达在Ret无效胚胎的ENS中也丢失。SEMA 3A，SEMA 3C和SEMA 3D在254例受HSCR影响的受试者中进行测序，然后通过计算机蛋白质结构建模和功能分析确定了5个疾病相关等位基因，这些等位基因在脑信号蛋白二聚化和与其同源神经纤毛蛋白和丛蛋白受体结合方面具有功能缺失缺陷。因此，semaphorin 3C/3D信号传导是ENS发育的进化上保守的调节器，其失调是肠道无神经节细胞症的原因。
Innervation of the gut is segmentally lost in Hirschsprung disease (HSCR), a consequence of cell-autonomous and non-autonomous defects in enteric neuronal cell differentiation, proliferation, migration, or survival. Rare, high-penetrance coding variants and common, low-penetrance non-coding variants in 13 genes are known to underlie HSCR risk, with the most frequent variants in the ret proto-oncogene (RET). We used a genome-wide association (220 trios) and replication (429 trios) study to reveal a second non-coding variant distal to RET and a non-coding allele on chromosome 7 within the class 3 Semaphorin gene cluster. Analysis in Ret wild-type and Ret-null mice demonstrates specific expression of Sema3a, Sema3c, and Sema3d in the enteric nervous system (ENS). In zebrafish embryos, sema3 knockdowns show reduction of migratory ENS precursors with complete ablation under conjoint ret loss of function. Seven candidate receptors of Sema3 proteins are also expressed within the mouse ENS and their expression is also lost in the ENS of Ret-null embryos. Sequencing of SEMA3A, SEMA3C, and SEMA3D in 254 HSCR-affected subjects followed by in silico protein structure modeling and functional analyses identified five disease-associated alleles with loss-of-function defects in semaphorin dimerization and binding to their cognate neuropilin and plexin receptors. Thus, semaphorin 3C/3D signaling is an evolutionarily conserved regulator of ENS development whose dys-regulation is a cause of enteric aganglionosis.