| First Author | Oberst L | Year | 1998 |
| Journal | J Clin Invest | Volume | 102 |
| Issue | 8 | Pages | 1498-505 |
| PubMed ID | 9788962 | Mgi Jnum | J:117554 |
| Mgi Id | MGI:3696895 | Doi | 10.1172/JCI4088 |
| Citation | Oberst L, et al. (1998) Dominant-negative effect of a mutant cardiac troponin T on cardiac structure and function in transgenic mice. J Clin Invest 102(8):1498-505 |
| abstractText | Hypertrophic cardiomyopathy (HCM) is a disease of sarcomeric proteins. The mechanism by which mutant sarcomeric proteins cause HCM is unknown. The leading hypothesis proposes that mutant sarcomeric proteins exert a dominant-negative effect on myocyte structure and function. To test this, we produced transgenic mice expressing low levels of normal or mutant human cardiac troponin T (cTnT). We constructed normal (cTnT-Arg92) and mutant (cTnT-Gln92) transgenes, driven by a murine cTnT promoter, and produced three normal and five mutant transgenic lines, which were identified by PCR and Southern blotting. Expression levels of the transgene proteins, detected using a specific antibody, ranged from 1 to 10% of the total cTnT pool. M-mode and Doppler echocardiography showed normal left ventricular dimensions and systolic function, but diastolic dysfunction in the mutant mice evidenced by a 50% reduction in the E/A ratio of mitral inflow velocities. Histological examination showed cardiac myocyte disarray in the mutant mice, which amounted to 1-15% of the total myocardium, and a twofold increase in the myocardial interstitial collagen content. Thus, the mutant cTnT-Gln92, responsible for human HCM, exerted a dominant-negative effect on cardiac structure and function leading to disarray, increased collagen synthesis, and diastolic dysfunction in transgenic mice. |
