PDF(Pubmed)
Abstract：
CACNA1S-related myopathy, due to pathogenic variants in the CACNA1S gene, is a recently described congenital muscle disease. Disease associated variants result in loss of gene expression and/or reduction of Cav1.1 protein stability. There is an incomplete understanding of the underlying disease pathomechanisms and no effective therapies are currently available. A barrier to the study of this myopathy is the lack of a suitable animal model that phenocopies key aspects of the disease. To address this barrier, we generated knockouts of the two zebrafish CACNA1S paralogs, cacna1sa and cacna1sb. Double knockout fish exhibit severe weakness and early death, and are characterized by the absence of Cav1.1 α1 subunit expression, abnormal triad structure, and impaired excitation-contraction coupling, thus mirroring the severe form of human CACNA1S-related myopathy. A double mutant (cacna1sa homozygous, cacna1sb heterozygote) exhibits normal development, but displays reduced body size, abnormal facial structure, and cores on muscle pathologic examination, thus phenocopying the mild form of human CACNA1S-related myopathy. In summary, we generated and characterized the first cacna1s zebrafish loss-of-function mutants, and show them to be faithful models of severe and mild forms of human CACNA1S-related myopathy suitable for future mechanistic studies and therapy development.
摘要：
CACNA1S相关肌病,由于CACNA1S基因的致病变异，是最近描述的一种先天性肌肉疾病。疾病相关变体导致基因表达的丧失和/或Cav1.1蛋白稳定性的降低。对潜在的疾病病理机制有不完全的了解，目前没有有效的治疗方法。研究这种肌病的一个障碍是缺乏一个合适的动物模型，该模型会影响疾病的关键方面。为了解决这个障碍，我们产生了两个斑马鱼CACNA1S旁系同源物的敲除，cacna1sa和cacna1sb。双基因敲除鱼表现出严重的虚弱和早期死亡，其特征在于缺乏Cav1.1α1亚基表达，三合会结构异常，和受损的激励-收缩耦合，因此反映了人类CACNA1S相关肌病的严重形式。双突变体(cacna1sa纯合，cacna1sb杂合子)表现出正常发育，但是显示缩小的身体尺寸，面部结构异常,以及肌肉病理检查的核心，从而显现人类CACNA1S相关肌病的轻度形式。总之,我们产生并表征了第一个cacna1s斑马鱼功能丧失突变体，并显示它们是严重和轻度形式的人类CACNA1S相关肌病的忠实模型，适用于未来的机理研究和治疗开发。
