Diastolic dysfunction and cardiac troponin I decrease in aging hearts

• Published in: Archives of biochemistry and biophysics Vol. 603; pp. 20 - 28
• Main Authors: Pan, B., Xu, Z.W., Xu, Y., Liu, L.J., Zhu, J., Wang, X., Nan, C., Zhang, Z., Shen, W., Huang, X.P., Tian, J.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.08.2016
• Subjects: Aging; Animals; Cardiomyopathies - metabolism; Chromatin Immunoprecipitation; Diastole; Diastolic dysfunction; Echocardiography; Epigenesis, Genetic; Epigenetics; Gene expression; Heart - physiology; Histone acetylation; Mice; Mice, Inbred C57BL; Myocardium - metabolism; Myocytes, Cardiac - metabolism; Promoter Regions, Genetic; Troponin; Troponin I - physiology; Epigenetics; Diastolic dysfunction; Troponin; Histone acetylation; Gene expression
• ISSN: 0003-9861; 1096-0384
• DOI: 10.1016/j.abb.2016.05.008

Cardiac tropnoin I (cTnI) plays a critical role in the regulation of diastolic function, and its low expression may result in cardiac diastolic dysfunction, which is the most common form of cardiovascular disorders in older adults. In this study, cTnI expression levels were determined in mice at various ages and cardiac function was measured and compared between young adult mice (3 and 10 months) and older mice (18 months). The data indicated that the cTnI levels reached a peak high in young adult hearts (3 months), but decreased in older hearts (18 months). Furthermore, the older hearts showed a significant diastolic dysfunction observed by P–V loop and echocardiography measurements. To further define the mechanism underlying the cTnI decrease in aging hearts, we tested DNA methylation and histone acetylation modifications of cTnI gene. We found that acetylation of histone near the promoter region of cTnI gene played an important role in regulation of cTnI expression in the heart at different ages. Our study indicates that epigenetic modification caused cTnI expression decrease is one of the possible causes that result in a reduced cTnI level and diastolic dysfunction in the older hearts. •Cardiac function is determined in young adult (3 months) and old (18 months) mice.•Impaired relaxation and cardiac troponin I decrease are observed in the heart of the old mice.•Epigenetic modifications play an important role in regulation of cTnI gene expression.