Serum cortisol level as a useful biomarker of increased cardiac event in patients with chronic heart failure-comparison with aldosterone

S156 Journal of Cardiac Failure Vol. 14 No. 7S September 2008 disease. Long-term treatment with NRTIs may be associated with severe adverse effect such as cardiac myopathy. We have been analyzing the mechanisms of the adverse effects of AZT and the active metabolite of AZT, AZT-triphosphate (AZTTP) in human T cells and revealed that AZT-TP caused the loss of mitochondrial inner membrane potential resulted in the activation of caspase-3 and the promotion of later apoptotic processes. To examine the mechanisms of AZT-induced myopathy, we established the wild type (WT) or active mutant form (mutant) of thymidylate kinase (tmpk) expressing mouse cardiac cells, H9C2. Although both WT and mutant tmpk expressing cells showed decreases in the cellular ATP levels in a dose-dependent manner following 4 days incubation with AZT, the IC50 of AZT to decrease ATP in mutant tmpk expressing cells was about 1/10 in that of WT tmpk, suggesting that accumulation of AZT-metabolites affect the mitochondrial function. The cardiac cell lines established in this study seem to be useful models for the evaluation of the cardiac toxicity of NRTIs including AZT and the investigation of the mechanisms of AZT-induced myopathy.

032 Down-regulation of TRPV4 in angiotensin II stimulated human coronary endothelial cells; an insight into the mechanism of endothelial dysfunction YOSHIKO MUNEHISA, HIROYUKI WATANABE, TAKAYOSHI OHBA, HITOSHI HASEGAWA, HIROSHI ITO Division of Cardiovascular and Respiratory Medicine, Department of Internal Medicine, University of Akita, Akita, Japan Background: Angiotensin II exerts deleterious effects on cardiovascular system through endothelial dysfunction. However, the ionic mechanism remains unclear. Transient receptor potential V4 channel (TRPV4) has been shown to be involved in endothelial Ca2+ transport induced by various endogenous stimulations including mechanical stress and 5’,6’-epoxyeicosatrienoic acid (5, 6-EET), and leads to NO production. The purpose of this study was to explore the potential involvement of TRPV4 in endothelial dysfunction. Method and Result: We studied human coronary artery endothelial cells (hCAECs), which constitutively express TRPV4. By using specific ligand 4 alpha-phorbol 12, 13-didecanoate (4aPDD) as a tool to stimulate TRPV4, we evaluated TRPV4 mediated Ca2+ entry in impaired endothelial cells which were treated with Ang II (100 nM) for 24e48 h. In Ang II treated hCAECs, 4aPDD induced an increase in [Ca2+]i but was 50% less effective than in untreated hCAECs. In path-clamp experiments, 4aPDD-induced nonselective current was decreased to half in Ang II treated hCAECs compared to control. Immunoblot revealed the down-regulation of TRPV4 protein in Ang II treated hCAECs. Moreover, NO production evoked by TRPV4 mediated Ca2+ entry was decreased in Ang II treated cells. Similar effects of Ang II were confirmed even by other TRPV4 stimuli, 30% hypotonic stress or 5, 6-EET. Conclusion: Down-regulation of TRPV4 in human endothelial cells might contribute to endothelial dysfunction.

033 Serum cortisol level as a useful biomarker of increased cardiac event in patients with chronic heart failure-comparison with aldosterone MASAYUKI YAMAJI, TAKAYOSHI TSUTAMOTO, KEIZO NISHIYAMA, CHIHO KAWAHARA, MASANORI FUJII, TAKASHI YAMAMOTO, MINORU HORIE Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Shiga, Japan Background: In patients with chronic heart failure (CHF), high levels of plasma aldosterone (ALD) are associated with poor prognosis and mineralocorticoid receptor blockade improves survival in these patients. The prognostic significance of cortisol that may also bind and activate the mineralocorticoid receptor remains unclear. Methods: We measured the plasma levels of biomarkers such as brain natriuretic peptide (BNP), plasma renin concentration (PRC), aldosterone (ALD), angiotensin II, and serum cortisol in 274 consecutive patients with CHF patients and then we prospectively followed-up for a mean period of 31 months. Results: During a mean follow-up period of 2.3 year,15 patients had cardiac events (CE) (death or hospitalization). Both plasma level of ALD (143 6 26 vs. 71 6 4 pg/ mL, p ! 0.0001) and serum cortisol (21 6 2.9 vs. 13 6 0.4 microg/dL, p ! 0.0001) were significantly higher in patients with CE(+) than CE(-) and both ALD and cortisol levels were significant prognostic predictors by univariate analysis. On stepwise multivariate analyses, plasma log BNP (p 5 0.0001), log PRC (p 5 0.0339), and serum cortisol (p 5 0.0032) were independent significant prognostic predictors but not plasma ALD. Conclusions: These results indicate that a high serum cortisol level was an independent predictor of increased cardiac event in patients with CHF.

034 Amlodipine increases p21 through PKD1-related pathway in Human Coronary Artery Smooth Muscle Cells TAKAYOSHI OHBA1, HIROYUKI WATANABE2, MANABU MURAKAMI1, HITOSHI HASEGAWA2, KYOICHI ONO1, HIROSHI ITO2 1 Department of Cellular Physiology, Akita University School of Medicine, 2 Department of Internal Medicine Division of Cardiovascular and Respiratory Medicine, Akita University School of Medicine Background: It has been shown that amlodipine suppresses vascular smooth muscle proliferation, however, the underlying mechanism remains unclear. Notable recent finding is the identification of PKD1, the product of the gene mutated polycystic kidney disease, which has an important role in cell growth regulation and involved in vascular morphogenesis. These evidences implied that there might be functional interaction between amlodipine and PKD1 and prompted us to test whether PKD1 related pathway can be modulated by amlodipine in vascular smooth muscle cells. Methods and Results: Cultured human coronary artery smooth muscle cells (hCASMCs) which constitutively express PKD1, were stimulated with serum. Amlodipine (10-9 to 10-6 M) increased p21(Waf1/Cip1) expression in dose- and time-dependent manner, and resulted in the reduction of hCASMCs proliferation. The inhibitory effect of amlodipine was mimicked by transient overexpression of PKD1. Transfection of dominant negative mutant of PKD1 (R4227X) reversed the inhibitory effects, suggesting contribution of PKD1 proteins in anti-proliferative action of amlodipine. In immunoblot assay, both amlodipine and PKD1 increased the protein level of phosphorylated Janus Kinase2 (pJAK2). Luciferase assay for STAT signaling pathway showed that PKD1 overexpression induced STAT1 enhancer activity but not STAT2 or -3. The activated signals of JAK2/STAT1 were reversed by PKD1 (R4227X). Conclusion: Amlodipine and subsequent activation of PKD1-related pathway suppresses hCASMC proliferation through activation of JAK2/ STAT1 signaling pathway and p21(Waf1/Cip1) induction.

035 Relationship between serum matrix metalloproteinases in the coronary sinus and left ventricular performance in patients with nonischemic dilated cardiomyopathy TOMOAKI OHTSUKA, TAKAYUKI NAGAI, KAZUHISA NISHIMURA, KATSUJI INOUE, JUN SUZUKI, AKIYOSHI OGIMOTO, HIDEKI OKAYAMA, JITSUO HIGAKI Division of Cardiology, Ehime University Graduate School of Medicine, Ehime, Japan Background: Recent studies have shown that circulating matrix metalloproteinases (MMPs) are closely associated with left ventricular (LV) remodeling and adverse cardiac events in patients with nonischemic dilated cardiomyopathy (DCM). We aimed to evaluate the relationship between serum profiles of MMPs in the coronary sinus (CS) and the LV performance in patients with DCM. Methods: We measured serum levels of MMP-2, MMP-3, and MMP-9 in the aortic root (Ao) and the CS using ELISA in 45 patients with DCM. Serum levels of N-terminal-pro-B-type natriuretic peptide (NT-proBNP) in the Ao and the CS were also measured. The LV volume and function were also assessed using echocardiography. Results: There were no defferences in serum levels of MMP-2 and MMP-9 between the Ao and the CS (both p O 0.05). However, serum levels of MMP-3 were significantly higher in the CS than those in the Ao (CS, 66.9 6 50.7 ng/ml; Ao, 61.9 6 48.5 ng/ml; p 5 0.023). The level of MMP-3 in the CS was significantly correlated with the value of early diastolic peak E velocity / early diastolic mitral annulus velocity (r 5 0.43, p 5 0.017). Moreover, there was a significant positive correlation between MMP-2 levels in the CS and the transcardiac gradient of NT-proBNP levels (r 5 0.39, p 5 0.03). Conclusion: Our results indicate that serum MMP-2 and MMP-3 in the CS may be closely associated with the LV performance in patients with DCM.

036 Statin therapy improve with exercise intolerance in patients with chronic heart failure? TOSHIO NAKA1, TSUYOSHI SAKODA1, TAKESHI TSUJINO2, TOHRU MASUYAMA2, MITSUMASA OHYANAGI1 1 Department of Internal Medicine, Division of Coronary Heart Disease, Hyogo College of Medicine, 2Department of Internal Medicine, Cardiovascular Division, Hyogo College of Medicine

Background: The 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitors (Statins) have pleiotrophic effects such as anti-inflammatory and anti-oxidant effects, which would be beneficial for patients with chronic heart failure(CHF). We