Abstract-Excessive fibrosis contributes to an increase in left ventricular stiffness. The goal of the present study was to investigate the role of connective tissue growth factor (CCN2/CTGF), a profibrotic cytokine of the CCN (Cyr61, CTGF, and Nov) family, and its functional interactions with brain natriuretic peptide (BNP), an antifibrotic peptide, in the development of myocardial fibrosis and diastolic heart failure. Histological examination on endomyocardial biopsy samples from patients without systolic dysfunction revealed that the abundance of CTGF-immunopositive cardiac myocytes was correlated with the excessive interstitial fibrosis and a clinical history of acute pulmonary congestion. In a rat pressure overload cardiac hypertrophy model, CTGF mRNA levels and BNP mRNA were increased in proportion to one another in the myocardium. Interestingly, relative abundance of mRNA for CTGF compared with BNP was positively correlated with diastolic dysfunction, myocardial fibrosis area, and procollagen type 1 mRNA expression. Investigation with conditioned medium and subsequent neutralization experiments using primary cultured cells demonstrated that CTGF secreted by cardiac myocytes induced collagen production in cardiac fibroblasts. Further, G protein-coupled receptor ligands induced expression of the CTGF and BNP genes in cardiac myocytes, whereas aldosterone and transforming growth factor-␤ preferentially induced expression of the CTGF gene. Finally, exogenous BNP prevented the production of CTGF in cardiac myocytes. These data suggest that a disproportionate increase in CTGF relative to BNP in cardiac myocytes plays a central role in the induction of excessive myocardial fibrosis and diastolic heart failure. Key Words: extracellular matrix Ⅲ hypertrophy Ⅲ cardiac function Ⅲ connective tissue growth factor Ⅲ natriuretic peptide E pidemiological studies have established that 40% to 50% of patients with heart failure have normal or minimally impaired left ventricular (LV) ejection fraction, a clinical syndrome that is commonly referred to as diastolic heart failure (DHF). These patients typically have cardiac hypertrophy that is induced by long-standing hypertension or by primary hypertrophic cardiomyopathy, as well as increased passive LV stiffness. 1 Among various molecular mechanisms that regulate LV stiffness, 2 abnormalities in the transcriptional or posttranscriptional regulation of the collagen gene can result in the disproportionate accumulation of fibrous tissue and elevation of stiffness in the hypertrophied heart. 2,3 Recent studies have shown that, in addition to mechanical load, autocrine, paracrine, and endocrine factors, such as angiotensin II, aldosterone (Aldo), endothelin-1 (ET1), natriuretic peptides, osteopontin, and transforming growth factor-␤1 (TGF-␤), play important roles in the development of myocardial hypertrophy and fibrosis. 4,5 However, the precise molecular mechanisms that initiate and promote myocardial fibrosis and increases in ventricular stiffness remain largely unknown.Connec...

Abstract-Beraprost sodium (BPS), an orally active prostacyclin analogue, has been reported to be beneficial in the treatment of primary pulmonary hypertension and obstructive peripheral arterial disease. Although BPS was originally described for its effects on platelet aggregation and vasodilatory response, the effect on endothelial cells has been poorly understood. In this study, we examined the effects of BPS on the eNOS gene expression in mouse aorta and cultured human and bovine aortic endothelial cells. Treatment of these cells with BPS increased the eNOS expression as assessed by Northern blots, Western blots, and NO production by NO-specific fluorescence (DAF2-DA) and by the Griess method. Standard mRNA decay assays showed that BPS increases the stability of eNOS mRNA. In addition, BPS increased the promoter activity of the human eNOS gene, as determined by luciferase assays of the eNOS promoter gene. Progressive 5Ј-deletion and site-specific mutation analyses defined the BPS-responsive sequences as cAMPresponsive elements (CRE) located at Ϫ733 and Ϫ603. By using the oligonucleotide probe containing this CRE sequence in electrophoretic mobility shift assays, we showed that the phosphorylated form of CRE-binding protein is a major constituent of the complex in BPS-treated cells.

Background: Connective tissue growth factor (CTGF) has been recently reported as a mediator of myocardial fibrosis; however, the significance of plasma CTGF concentration has not been evaluated in patients with heart failure. The aim of this study was to investigate the clinical utility of plasma CTGF concentration for the diagnosis of heart failure. Methods and results: We evaluated fifty-two patients with chronic heart failure. The plasma concentration of CTGF and other markers of fibrosis were assessed and compared with clinical and echocardiographic data. Plasma CTGF was significantly elevated in symptomatic patients in proportion to their NYHA classes and was significantly correlated with plasma brain natriuretic peptide (BNP) concentration (r = 0.395, P b 0.01). Plasma CTGF was also correlated with plasma transforming growth factor beta (TGF-β) (r = 0.512, P b 0.01), matrix metalloproteinase (MMP)-2 (r = 0.391, P b 0.05) and tissue inhibitor of MMP (TIMP)-2 (r = 0.354, P b 0.05) concentrations. Interestingly, plasma CTGF was correlated with E/E' value evaluated by tissue Doppler echocardiography (r = 0.593, P = 0.012), but not with systolic function and left ventricular mass. Conclusion: Our study suggests that plasma CTGF concentration is a novel diagnostic marker for cardiac dysfunction and may provide additional specific information about myocardial fibrosis in chronic heart failure patients.

Reduced expression of the SERCA2 gene impairs the calcium-handling and contractile functions of the heart. We developed an SERCA2 gene transfer system using lentiviral vectors, and examined the long-term effect of SERCA2 gene transfer in the rat ischemic heart failure model. A lentiviral vector containing the SERCA2 gene was infused into a rat heart by hypothermic intracoronary delivery 2 weeks after myocardial infarction (MI). The transduction efficiency was approximately 40%. Six months after transduction, echocardiogram and pressure-volume measurements revealed that the SERCA2 gene transfer had significantly protected against left ventricular (LV) dilation, and had improved systolic and diastolic function, resulting in reduction in mortality rates. The brain natriuretic peptide mRNA level showed a significantly decrease and the phosphorylation level of serine residue of phospholamban (PLN) showed an increase in the Lenti-SERCA2-transduced heart. Further, DNA microarray analysis disclosed that SERCA2 gene transfer had increased cardioprotective gene expression and lowered the expression of genes that are known to exacerbate heart failure. The SERCA2 gene was successfully integrated into the host heart, induced favorable molecular remodeling, prevented LV geometrical remodeling, and improved the survival rate. These results suggest that a strategy to compensate for reduced SERCA2 gene expression by lentiviral vectors serves as a positive inotropic, lucitropic, and cardioprotective therapy for post-MI heart failure.