Loss-of-function mutations in the co-chaperone protein BAG5 cause dilated cardiomyopathy requiring heart transplantation

التفاصيل البيبلوغرافية
العنوان: Loss-of-function mutations in the co-chaperone protein BAG5 cause dilated cardiomyopathy requiring heart transplantation
المؤلفون: Hakui, Hideyuki, Kioka, Hidetaka, Miyashita, Yohei, Nishimura, Shunsuke, Matsuoka, Ken, Kato, Hisakazu, Tsukamoto, Osamu, Kuramoto, Yuki, Takuwa, Ayako, Takahashi, Yusuke, Saito, Shigeyoshi, Ohta, Kunio, Asanuma, Hiroshi, Fu, Hai Ying, Shinomiya, Haruki, Yamada, Noriaki, Ohtani, Tomohito, Sawa, Yoshiki, Kitakaze, Masafumi, Takashima, Seiji, Sakata, Yasushi, Asano, Yoshihiro
المصدر: Science Translational Medicine; January 2022, Vol. 14 Issue: 628
مستخلص: Dilated cardiomyopathy (DCM) is a major cause of heart failure, characterized by ventricular dilatation and systolic dysfunction. Familial DCM is reportedly caused by mutations in more than 50 genes, requiring precise disease stratification based on genetic information. However, the underlying genetic causes of 60 to 80% of familial DCM cases remain unknown. Here, we identified that homozygous truncating mutations in the gene encoding Bcl-2–associated athanogene (BAG) co-chaperone 5 (BAG5) caused inherited DCM in five patients among four unrelated families with complete penetrance. BAG5 acts as a nucleotide exchange factor for heat shock cognate 71 kDa protein (HSC70), promoting adenosine diphosphate release and activating HSC70-mediated protein folding. Bag5mutant knock-in mice exhibited ventricular dilatation, arrhythmogenicity, and poor prognosis under catecholamine stimulation, recapitulating the human DCM phenotype, and administration of an adeno-associated virus 9 vector carrying the wild-type BAG5gene could fully ameliorate these DCM phenotypes. Immunocytochemical analysis revealed that BAG5 localized to junctional membrane complexes (JMCs), critical microdomains for calcium handling. Bag5-mutant mouse cardiomyocytes exhibited decreased abundance of functional JMC proteins under catecholamine stimulation, disrupted JMC structure, and calcium handling abnormalities. We also identified heterozygous truncating mutations in three patients with tachycardia-induced cardiomyopathy, a reversible DCM subtype associated with abnormal calcium homeostasis. Our study suggests that loss-of-function mutations in BAG5can cause DCM, that BAG5may be a target for genetic testing in cases of DCM, and that gene therapy may potentially be a treatment for this disease.
قاعدة البيانات: Supplemental Index
الوصف
تدمد:19466234
19466242
DOI:10.1126/scitranslmed.abf3274