Myocardial regulatory proteins and heart failure

Abstract

Cardiac troponin T (cTnT) and cardiac troponin I (cTnI) are considered to be the most specific and sensitive biochemical markers of myocardial damage. Troponins have been studied in a wide range of clinical settings, including heart failure; however, there are few data on the role of regulatory proteins in the pathogenesis of heart failure, although a few interesting hypotheses have been proposed. A considerable body of evidence favours the view that alteration of the myocardial thin filament is the primary event leading to defective contractility of the failing myocardium, while the changes in Ca 2+ handling are a compensatory response. A better understanding of the role of regulatory proteins under different physiological and pathological conditions could lead to new therapeutic approaches in heart failure. Recently, calcium sensitisation has been proposed as a novel method by which cardiac performance may be enhanced via an increase in the affinity of troponin C for calcium but without affecting intracellular calcium concentration. To date, the only calcium sensitizer used in clinical practice is levosimendan.

Right ventricular dyssynchrony in idiopathic pulmonary arterial hypertension: Determinants and impact on pump function

“…[20][21][22][23] These pathophysiologic consequences together with RV myocardial ischemia [24][25] and increased cardiomyocyte apoptotic rates, 26-28 both described in chronically increased RV wall stress, may ultimately affect RV contractile performance and thus the systolic function parameters. Unexpectedly, among all RV systolic function parameters, TAPSE was the only one to show no significant difference between the two groups of patients.…”

Molecular characterization and immunohistochemical localization of a novel troponin C during silkworm development

“…The Ca 2+ -binding subunit, TnC, was the first component of this complex that was identified and characterized. Although, unlike the other two components of this protein complex, TnC has no cardiac specificity (Schreier et al 1990), it can be used as a target for calcium sensitizers when screening for cardiomyopathy (Kawai et al 2000;Ming et al 2000;Wang et al 2002;Adamcova et al 2006;Garcia Gonzalez and Dominguez Rodriguez 2006).…”

The Right Ventricle Under Pressure

“…The myocardial regulatory proteins troponin, tropomyosin, and tropomodulin may also be involved in the pathobiology of heart failure. 25,26 Proteolytic degradation of troponin subunits likely plays a functional role in ischemic cardiomyopathy. Phosphorylation of troponin T by protein kinase C inhibits troponin T binding to tropomyosin that may contribute to the inhibition of maximal myofibrillar adenosine triphosphatase and contractile performance.…”