Cardiac signaling molecules and plasma biomarkers after cardiac transplantation: impact of tacrolimus versus cyclosporine.

BACKGROUND: We investigated cardiac proinflammatory, mitogenic, and apoptotic signaling events, and plasma biomarkers of inflammation and oxidative stress in de novo adult cardiac transplant (CTX) patients receiving tacrolimus (TAC) or cyclosporine A (CsA). METHODS: One hundred CTX recipients were randomized 1:1 to TAC/CsA in a prospective, randomized open-label multicenter study. Biomarkers of inflammation, immunity, oxidative stress, and cardiac signaling underlying growth and inflammation (extracellular signal-related kinase 1/2, p38 mitogen-activated protein kinase, mitogen-activated protein kinase kinases [MEK] 1/2 and 3/6, c-Src), and apoptosis and survival (c-Jun NH2-terminal kinases [JNK], Bax/Bcl2, Akt) were assessed at 2, 4, 12, 26, and 52 weeks post-CTX. Plasma from healthy controls (n = 30) and tissue from explanted non-failing hearts (n = 6) were used as controls. RESULTS: Biomarkers of inflammation/immunity (interleukin -6 and -18, soluble intercellular adhesion molecule, E-selectin, monocyte chemoattractant protein-1, osteopontin, fibrinogen, N-terminal prohormone brain natriuretic peptide, high-sensitive C-reactive protein) and oxidative stress (thiobarbituric acid reactive substances, nitrotyrosine) were increased, and antioxidant capacity was (glutathione/glutathione disulfide) decreased in patients vs healthy controls (p < 0.05). Phosphorylation of mitogen-activated protein kinases and Akt was increased, and Bax/Bcl was decreased in transplanted vs non-transplanted hearts. Except for plasma fibrinogen, which was lower in TAC vs. CsA, (p = 0.01), there were no significant differences in parameters studied between TAC vs CsA immunoprophylaxis. CONCLUSIONS: De novo CTX recipients exhibit significant sub-clinical inflammation and oxidative stress that persists 12 months after transplantation. Associated with this is activation of myocardial growth and inflammatory signaling and decreased apoptosis. Our findings suggest that CTX is an inflammatory condition associated with oxidative stress and myocardial growth regardless of CsA or TAC immunoprophylaxis and independently of rejection status.

Effects of angiotensin-converting enzyme inhibitor versus valsartan on cellular signaling events in heart transplant.

BACKGROUND: Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) provide similar biologic effects in model systems and similar clinical impacts in humans. The changes in the cardiac angiotensin system signaling pathways in the human heart in response to ACE inhibitors versus ARBs have been incompletely studied. OBJECTIVE: To investigate the effects of ACE inhibitors versus valsartan on the angiotensin II signal transduction pathways in the transplanted human heart. METHODS: Twenty-seven stable cardiac transplant recipients were randomized to remain on ACE inhibitor therapy (n = 8) or to receive valsartan (n = 19). Two additional endomyocardial biopsy samples were obtained at baseline and after 9 months of therapy. The expression of cardiac angiotensin type I and II receptors and atrial natriuretic factor (ANF) was measured by quantitative polymerase chain reaction. The expression and phosphorylation levels of selected signal transduction pathways were analyzed by immunoblotting. RESULTS: The mean dose of valsartan was 114 +/- 41 mg/day. The use of valsartan resulted in a similar impact on blood pressure and biochemistry profile. There were no significant changes in the expression of angiotensin type I and II receptors and ANF with valsartan. Similarly, no significant changes in the expression and phosphorylation of Jun N-terminal kinase, extracellular signal-regulated kinase 1 and 2, and p38 mitogen-activated protein kinases or AKT, and mammalian target of rapamycin was observed in the valsartan-treated group. CONCLUSIONS: Valsartan use is associated with similar clinical and molecular cardiac effects as ACE inhibitor therapy in stable long-term cardiac transplant recipients.

Effects of AGTR1 A1166C gene polymorphism in patients with heart failure treated with candesartan.

BACKGROUND: The benefits of angiotensin II receptor blockers (ARBs) in patients with heart failure who are treated with standard pharmacotherapy, including an angiotensin-converting enzyme (ACE) inhibitor, were demonstrated in 2 large randomized trials. It is currently impossible to determine which patient will benefit from the addition of an ARB. OBJECTIVE: To explore the impact of selected candidate genes on the hemodynamic, neurohormonal, and antiinflammatory effects of candesartan in patients with heart failure who are already being treated with an ACE inhibitor. METHODS: We investigated the impact of 10 candidate genetic polymorphisms on the effects of candesartan in patients with heart failure who are treated with an ACE inhibitor. We evaluated their impact on acute (2 wk) and long-term (24 wk) changes in blood pressure and N-terminal proB-type natriuretic peptide (NT-proBNP) and high sensitivity C-reactive protein (hsCRP) during treatment with candesartan. RESULTS: Thirty-one patients were included. Homozygotes of the AGTR1 A1166 allele (n = 13) had a greater decrease in systolic (-9.1 +/- 4.7 vs 1.1 +/- 3.3 mm Hg; p = 0.04 by analysis of variance [ANOVA], adjusting for dose) and diastolic blood pressure (-5.1 +/- 1.5 vs 1.9 +/- 1.9 mm Hg; p = 0.005 by ANOVA, adjusting for dose) compared with C1166 allele carriers (n = 18) following 2 weeks of treatment. After 6 months of treatment, C1166 carriers experienced a greater decrease in NT-proBNP (-151.4 [-207; -19.8] ng/L vs 147.3 [-61.3; 882.9] ng/L; p = 0.03) and hsCRP (-0.8 [-2.2; -0.03] mg/L) vs 0.2 [-1.8; 5.3] mg/L; p = 0.09) compared with patients carrying the AA1166 genotype. No other significant association was found. CONCLUSIONS: The results of this proof-of concept study provide the first evidence that the AGTR1 A1166C polymorphism could influence the response to candesartan in patients with heart failure who are receiving ACE inhibitors. Validation of these exploratory findings in larger populations is required before use of the AGTR1 A1166C genotype can be incorporated into clinical practice.

Effects of combined candesartan and ACE inhibitors on BNP, markers of inflammation and oxidative stress, and glucose regulation in patients with symptomatic heart failure.

BACKGROUND: We assessed the effects of candesartan in addition to angiotensin-converting enzyme (ACE) inhibitors on N-terminal pro-type natriuretic peptide (Nt-proBNP), systemic markers of inflammation and oxidative stress as well as on glucose regulation in patients with heart failure (HF). METHODS AND RESULTS: Eighty patients with HF ages 62.5 +/- 8.4 years presenting mostly with New York Heart Association class II symptoms (class II = 57.5%, III = 41.3%), and mean left ventricular ejection fraction 27.1 +/- 7.3% were recruited. The patients were randomized to receive candesartan titrated to 32 mg 1 per day versus placebo in double-blind fashion for 6 months. Nt-proBNP, markers of inflammation and oxidative stress, glucose, insulin, and fasting insulin resistance index were analyzed. Candesartan decreased Nt-proBNP (median value = 12.4% versus -20.4%; [candesartan] P = .05), and high-sensitivity C-reactive protein (hsCRP) (+5.32% versus -20.3% [candesartan]; P = 0.046), without significantly influencing serum interleukin-6, interleukin-18, adhesion molecules, or markers of oxidative stress. Blood glucose decreased in patients treated with candesartan with a significantly greater effect in patients with higher blood glucose levels (P < .01 for interaction). CONCLUSIONS: The addition of candesartan to ACE inhibitor and beta-blocker decreases Nt-proBNP and hsCRP, but does not change the other markers of inflammation or oxidative stress in patients with heart failure. Dual angiotensin-II suppression also decreased blood glucose with a greater impact in patients with higher blood glucose level.

Increased systemic inflammation and oxidative stress in patients with worsening congestive heart failure: improvement after short-term inotropic support.

In the present study, we evaluated circulating pro-inflammatory mediators and markers of oxidative stress in patients with decompensated CHF (congestive heart failure) and assessed whether clinical recompensation by short-term inotropic therapy influences these parameters. Patients with worsening CHF (n=29, aged 61.9+/-2.7 years), NYHA (New York Heart Association) class III-IV, and left ventricular ejection fraction of 23.7+/-1.8% were studied. Controls comprised age-matched healthy volunteers (n=15; 54.1+/-3.2 years). Plasma levels of cytokines [IL (interleukin)-6 and IL-18], chemokines [MCP-1 (monocyte chemotactic protein-1)], adhesion molecules [sICAM (soluble intercellular adhesion molecule), sE-selectin (soluble E-selectin)], systemic markers of oxidation [TBARS (thiobarbituric acid-reactive substances), 8-isoprostaglandin F(2alpha) and nitrotyrosine] and hs-CRP (high-sensitivity C-reactive protein) were measured by ELISA and colorimetric assays at admission and 30 days following 72-h milrinone (n=15) or dobutamine (n=14) infusion. Plasma IL-6, IL-18, sICAM, E-selectin, hs-CRP and oxidative markers were significantly higher in patients on admission before inotropic treatment compared with controls (P<0.05). Short-term inotropic support improved clinical status as assessed by NYHA classification and by the 6-min walk test and significantly decreased plasma levels of IL-6, IL-18, sICAM, hs-CRP and markers of oxidation (P<0.05) at 30 days. The effects of milrinone and dobutamine were similar. In conclusion, our results demonstrate that patients with decompensated CHF have marked systemic inflammation and increased production of oxygen free radicals. Short-term inotropic support improves functional status and reduces indices of inflammation and oxidative stress in patients with decompensated CHF.