First Author | Harris SP | Year | 2002 |
Journal | Circ Res | Volume | 90 |
Issue | 5 | Pages | 594-601 |
PubMed ID | 11909824 | Mgi Jnum | J:95725 |
Mgi Id | MGI:3526876 | Doi | 10.1161/01.res.0000012222.70819.64 |
Citation | Harris SP, et al. (2002) Hypertrophic cardiomyopathy in cardiac myosin binding protein-C knockout mice. Circ Res 90(5):594-601 |
abstractText | Familial hypertrophic cardiomyopathy (FHC) is an inherited autosomal dominant disease caused by mutations in sarcomeric proteins. Among these, mutations that affect myosin binding protein-C (MyBP-C), an abundant component of the thick filaments, account for 20% to 30% of all mutations linked to FHC. However, the mechanisms by which MyBP-C mutations cause disease and the function of MyBP-C are not well understood. Therefore, to assess deficits due to elimination of MyBP-C, we used gene targeting to produce a knockout mouse that lacks MyBP-C in the heart. Knockout mice were produced by deletion of exons 3 to 10 from the endogenous cardiac (c) MyBP-C gene in murine embryonic stem (ES) cells and subsequent breeding of chimeric founder mice to obtain mice heterozygous (+/-) and homozygous (-/-) for the knockout allele. Wild-type (+/+), cMyBP-C(+/-), and cMyBP-C(-/-) mice were born in accordance with Mendelian inheritance ratios, survived into adulthood, and were fertile. Western blot analyses confirmed that cMyBP-C was absent in hearts of homozygous knockout mice. Whereas cMyBP-C(+/-) mice were indistinguishable from wild-type littermates, cMyBP-C(-/-) mice exhibited significant cardiac hypertrophy. Cardiac function, assessed using 2-dimensionally guided M-mode echocardiography, showed significantly depressed indices of diastolic and systolic function only in cMyBP-C(-/-) mice. Ca2+ sensitivity of tension, measured in single skinned myocytes, was reduced in cMyBP-C(-/-) but not cMyBP-C(+/-) mice. These results establish that cMyBP-C is not essential for cardiac development but that the absence of cMyBP-C results in profound cardiac hypertrophy and impaired contractile function. |