PDF(Pubmed)
Abstract：
Acrokeratoelastoidosis (AKE) is a rare autosomal dominant hereditary skin disease characterized by small, round-oval, flat-topped keratotic papules on the palms, soles and dorsal aspect of hands or feet. The causative gene for AKE remains unidentified. This study aims to identify the causative gene of AKE and explore the underlying biological mechanisms. A large, three-generation Chinese family exhibiting classic AKE symptoms was identified. A genome-wide linkage analysis and whole-exome sequencing were employed to determine the causative gene. shRNA knockdown in human skin fibroblasts and CRISPR/Cas9 knockout in HEK293T cells were utilized to assess gene functions in the progression of elastic fiber biosynthesis. The linkage analysis identified a susceptibility region between rs7296765 to rs10784618 on chromosome 12. Whole-exome sequencing confirmed a splicing mutation of 1101 + 1 G > A in the CCDC91 gene, resulting in exon 11 skipping and a subsequent 59-amino-acid-residue loss (residues L309-Q367del). Further functional analysis revealed distended Golgi cisternae, cytoplasmic vesicle accumulation, and lysosome presence. Immnunostaining of si-CCDC91-HSF cells demonstrated tropoelastin accumulation in the Golgi and abnormal extracellular aggregates. There are no significant changes in Fibrillin-1 microfibril assembly and lysyl oxidase activity. The findings strongly suggest that the protein product of the CCDC91 gene plays a crucial role in elastin transport. This discovery enhances our understanding of CCDC91\'s function and broadens the known pathogenic mechanisms of AKE.
摘要：
去角化弹性组织（AKE）是一种罕见的常染色体显性遗传性皮肤病，其特征是小，圆形椭圆形,手掌上的平顶角化丘疹，手或脚的脚底和背侧。AKE的致病基因仍未确定。本研究旨在鉴定AKE的致病基因并探讨其潜在的生物学机制。一个大的，确定了表现出经典AKE症状的三代中国家庭。采用全基因组连锁分析和全外显子组测序来确定致病基因。人皮肤成纤维细胞中的shRNA敲除和HEK293T细胞中的CRISPR/Cas9敲除用于评估弹性纤维生物合成进展中的基因功能。连锁分析确定了12号染色体上rs7296765与rs10784618之间的易感区域。全外显子组测序证实CCDC91基因有1101+1G>A的剪接突变,导致外显子11跳跃和随后的59个氨基酸残基丢失（残基L309-Q367del）。进一步的功能分析显示高尔基池扩张，细胞质囊泡积累，和溶酶体的存在。si-CCDC91-HSF细胞的免疫染色显示了高尔基体中的原弹性蛋白积累和异常的细胞外聚集体。Fibrillin-1微原纤维组装和赖氨酰氧化酶活性没有显着变化。研究结果强烈表明，CCDC91基因的蛋白质产物在弹性蛋白转运中起着至关重要的作用。这一发现增强了我们对CCDC91功能的理解，并拓宽了已知的AKE致病机制。
