Zebrafish models of muscular dystrophies

描述（由申请人提供）：肌营养不良是一组不同的原发性遗传性疾病，其特征是骨骼肌进行性无力和变性。该项目的长期目标是使用两种遗传上不同形式的脊椎动物模型来了解肌营养不良症的分子基础，并为患有这些衰弱疾病的患者开发治疗方法。先天性强直性脊柱肌营养不良症（RSMD 1）在出生时或婴儿早期出现，由SEPN 1基因突变引起，而强直性肌营养不良症（MMD）通常出现在成年期，最近与BIN 1基因的错误剪接有关。有趣的是，SEPN 1和BIN 1都编码对T-小管的生物发生和功能重要的蛋白质，T-小管是骨骼肌中负责三联体兴奋-收缩偶联的结构。为了进一步阐明这些分子相关病症的病理生理学，并大规模筛选小分子治疗剂，需要适当的脊椎动物模型。斑马鱼，由于其体积小，透明度，高增殖能力，以及良好的特征基因组，最近出现了作为一个强大的遗传工具，在发育生物学和RSMD 1和MMD的可靠模型，在这里提出。该项目的具体目标是1）在斑马鱼中创建和表征bin 1和sepn 1基因的靶向敲除，2）开发这些突变体用于高通量药物筛选，以鉴定具有RSMD 1和MMD治疗潜力的先导化合物。这些研究的成功结论将增加对这些疾病的基本生物学、受影响的系统以及导致骨骼肌无力的机制的一般理解。此外，鉴定出减缓或预防骨骼肌紊乱的小分子将为临床前测试新疗法奠定基础，这些新疗法可用于治疗肌营养不良症和其他相关神经肌肉疾病患者。

DESCRIPTION (provided by applicant): Muscular dystrophies are a diverse group of primary inherited disorders characterized by progressive weakness and degeneration of skeletal muscle. The long-term goals of this project are to understand the molecular basis of muscular dystrophies using vertebrate models of two genetically distinct forms, and to develop therapies for patients with these debilitating conditions. Congenital rigid spine muscular dystrophy (RSMD1) manifests at birth or in early infancy and is caused by mutations in the SEPN1 gene, whereas myotonic muscular dystrophy (MMD) commonly presents in adulthood and has recently been associated with mis-splicing of the BIN1 gene. Interestingly, SEPN1 and BIN1 both encode proteins important for the biogenesis and function of T-tubules, the structures in skeletal muscles responsible for excitation-contraction coupling at the triads. To further elucidate the pathophysiology of these molecularly related conditions, and to screen small molecule therapeutics on a large scale, appropriate vertebrate models are required. Zebrafish, due to their small size, transparency, high proliferative capacity, and well-characterized genome, have recently emerged as a powerful genetic tool in developmental biology and are proposed here as reliable models for RSMD1 and MMD. The specific aims of this project are 1) to create and characterize targeted knockouts of the bin1 and sepn1 genes in zebrafish, and 2) to develop these mutants for use in high throughput drug screens to identify lead compounds with therapeutic potential for RSMD1 and MMD. The successful conclusion of these studies will increase general understanding of the basic biology of these disorders, the affected systems, and the mechanisms that lead to skeletal muscle weakness. Furthermore, the identification of small molecules that slow or prevent derangements of skeletal muscle will set the stage for preclinical testing of new therapies that may be used to treat patients with muscular dystrophy and other related neuromuscular diseases.