遗传因素在扩张型心肌病(DCM)发生发展中起着重要作用。课题组前期发现：fam13c基因新突变P181L伴随DCM表型分离；H9c2细胞中研究发现P181L功能缺失，具“显性负效应”；IP-质谱鉴定到以actin细胞骨架通路及DCM通路为主的互作蛋白430个；CRISPR-Cas9敲除fam13c斑马鱼胚胎心脏扩大、电镜发现心肌纤维减少、qPCR发现actin、TPM3等mRNA下调。前期工作表明P181L致fam13c功能降低/缺失，可能影响actin细胞骨架通路及DCM通路等，导致DCM。本项目拟通过突变分析、质粒转染、基因敲除小鼠/斑马鱼和突变小鼠、超声、MRI、Co-IP、免疫荧光、电镜、转录组测序等研究，明确fam13c功能、关键互作蛋白及P181L致DCM的具体分子机制；野生型fam13c显微注射胚胎/腺相关病毒心肌内注射小鼠恢复试验等研究，探索fam13c治疗DCM的可行性。

Genetic factor is essential for dilated cardiomyopathy (DCM) pathogenesis. Recently, the P181L mutation of fam13c gene has been identified by our group through the Whole Exome Sequencing (WES) analysis in a pedigree of familial DCM. The P181L mutation showed loss of function with dominant-negative effect in H9c2 cells. IP-protein mass-spectrography analysis identified 430 interacting protein including cytoskeleton actin and DCM signaling proteins. Zebrafish embryos with fam13c knockout by CRISPR-Cas9 system show significant dilated heart, less cardiac muscle fibers and reduced actin/TPM3 expression appear in the mutant embryo. These results suggest that P181L leads function loss and DCM phenotype through downregulation of cytoskeleton actin and DCM signaling proteins. We plan to study the gene function by analyzing fam13c gene mutation, transfecting mutant plasmid and establishing knockout or mutant mouse and zebrafish. Echocardiography and MRI analysis will be used to investigate the role of fam13c and its mutation for cardiac structure and function in model organism. We are also going to use assays of Co-IP, IF, electron microscope, confocal microscope and transcriptome to identify the interacting proteins. In addition, we plan to perform recovery experiments to explore the possibility of DCM therapy by fam13c using microinjection wild type fam13c to embryo or injection of adeno associated virus to mouse heart muscle.