osteoprotegerin and Heart-Failure--Systolic

Circulating and myocardial expressions of receptor activator of nuclear factor-κb ligand and osteoprotegerin are activated in heart failure; however, it remains to be determined their pathophysiological roles on left ventricular structure and function in interaction with renin-angiotensin system. We conducted experiments using 8-week-old osteoprotegerin(-/-) mice and receptor activator of nuclear factor-κb ligand-transgenic mice to assess whether they affect the angiotensin II-induced left ventricular remodeling. Subcutaneous infusion of angiotensin II to osteoprotegerin(-/-) mice progressed the eccentric hypertrophy, resulting in left ventricular systolic dysfunction for 28 days, and this was comparable with wild-type mice, showing concentric hypertrophy, irrespective of equivalent elevation of systolic blood pressure. The structural alteration was associated with reduced interstitial fibrosis, decreased procollagen α1 and syndecan-1 expressions, and the increased number of apoptotic cells in the left ventricle, compared with wild-type mice. In contrast, angiotensin II infusion to the receptor activator of nuclear factor-κb ligand-transgenic mice revealed the concentric hypertrophy with preserved systolic contractile function. Intraperitoneal administration of human recombinant osteoprotegerin, but not subcutaneous injection of anti-receptor activator of nuclear factor-κb ligand antibody, to the angiotensin II-infused osteoprotegerin(-/-) mice for 28 days ameliorated the progression of heart failure without affecting systolic blood pressure. These results underscore the biological activity of osteoprotegerin in preserving myocardial structure and function during the angiotensin II-induced cardiac hypertrophy, independent of receptor activator of nuclear factor-κb ligand activity. In addition, the antiapoptotic and profibrotic actions of osteoprotegerin that emerged from our data might be involved in the mechanisms.

Topics: Angiotensin II; Animals; Disease Models, Animal; Follow-Up Studies; Heart Failure, Systolic; Hypertrophy, Left Ventricular; Male; Mice; Mice, Transgenic; Osteoprotegerin; Random Allocation; Rats; Rats, Wistar; Renin-Angiotensin System; Ventricular Remodeling

Osteoprotegerin (OPG) may predict progression of chronic congestive heart failure (CHF) with increased mortality and play an important role in the development of pulmonary arterial hypertension (PAH). Mounting evidence suggests that PAH developed during CHF is not solely caused by a "passive" increase from the left ventricular enddiastolic pressure, but rather a "reactive" response from contributing lung endothelial dysfunction and vascular remodelling, a pathological process that can be significantly influenced by endothelial progenitor cells (EPCs).This study aims to examine whether circulating EPCs from patients with CHF are affected and if OPG could be implicated during disease progression.. In this study EPCs were isolated, cultured, and quantified from patients of CHF with (n = 20) or without PAH (n=40) as measured by right heart catheterization. Serum levels of OPG and N-terminal pro-brain natriuretic peptide (NT-pro BNP) were analysed and correlated with EPCs.. A significant decrease in circulating EPCs (39.3 ?9.1 vs 67.1 ?10.5 EPCs/x200 field; P <0.05) was found in CHF patients who developed PAH compared to those without PAH. Both OPG (551.90 +/- 49.83 vs. 312.29 +/- 31.12 pg/ml; P<0.05) and NT-pro BNP (2,946.50 +/- 1,434.50 vs. 1,328.20 +/- 811.90; P < 0.05) were also significantly elevated in CHF patients with PA H. Circulating level of OPG correlated inversely with EPCs (r = -0.45, P = 0.037) but positively with mPAP (r =0.53, P=0.011).. Our study demonstrates that OPG elevation and EPC depletion are associated with CHF patients who have developed PAH. The inverse relationship of circulating OPG with EPCs suggests a possible mechanism for OPG in the development of pulmonary vascular dysfunction, thus worsening prognosis for CHF patients.

Topics: Adult; Cells, Cultured; Disease Progression; Echocardiography, Doppler, Color; Endothelial Progenitor Cells; Endothelium, Vascular; Female; Heart Failure, Systolic; Humans; Hypertension, Pulmonary; Male; Middle Aged; Natriuretic Peptide, Brain; Osteoprotegerin; Peptide Fragments; Prognosis