pitavastatin and Hypertrophy--Left-Ventricular

The pleiotropic effects of HMG-CoA reductase inhibitors (statins) are thought to be mediated through inhibition of small GTP-binding proteins; however, it remains to be examined whether clinical concentrations/doses of statins actually exert them.. In vitro studies with cultured human umbilical venous endothelial cells found that statins (atorvastatin, pitavastatin and pravastatin at 10 micromol/L) had no inhibitory effects on RhoA/Rho-kinase or Ras, but atorvastatin and pitavastatin inhibited membrane Rac1 expression. In animal studies of angiotensin II (AngII)-infused rats, atorvastatin showed only mild inhibitory effects on AngII-induced cardiovascular hypertrophy, whereas fasudil, a selective Rho-kinase inhibitor, significantly suppressed it. Statins had no inhibitory effects on RhoA/Rho-kinase, but inhibited both membrane and GTP-bound Rac1 in the heart, whereas fasudil only inhibited Rho-kinase activity. Furthermore, the combination of atorvastatin and fasudil showed more effective inhibitory effects than fasudil alone. Finally, in studies of normal healthy volunteers, clinical doses of pravastatin or atorvastatin (20 mg/day for 1 week) significantly inhibited Rac1, but not RhoA/Rho-kinase activity, in circulating leukocytes.. The pleiotropic effects of statins, if any, at their clinical doses are mediated predominantly through inhibition of the Rac1 signaling pathway.

Topics: 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; Adult; Angiotensin II; Animals; Atorvastatin; Cells, Cultured; Cross-Over Studies; Endothelium, Vascular; Female; Heptanoic Acids; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypertrophy, Left Ventricular; Leukocytes; Male; Pravastatin; Pyrroles; Quinolines; rac1 GTP-Binding Protein; ras Proteins; Rats; Rats, Inbred WKY; rho-Associated Kinases; rhoA GTP-Binding Protein; Signal Transduction

3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins), which are widely used to lower plasma cholesterol levels, have been reported to have various pleiotropic effects such as protective effect of endothelial cells, angiogenic effect, antioxidant effect and anti-inflammatory effect. It is unclear, however, whether statins have any effects on the progression from left ventricular (LV) hypertrophy to heart failure in the established hypertrophied heart.. C57BL/6 mice were treated with pitavastatin (pitava) or vehicle (control) from 2 weeks (established hypertrophy stage) after transverse aortic constriction (TAC) and the treatment was continued for 4 weeks. Pitavastatin significantly inhibited the progression from LV hypertrophy to heart failure as assessed on echocardiography. The cardiomyocyte cross-sectional area was significantly increased in the control group compared to the sham-operated mice (sham group), but it was not significantly different between the control group and the pitava group at 6 weeks after TAC. Moreover, pitavastatin induced myocardial angiogenesis (ratio of number of endothelial cells to cardiomyocytes) and decreased the myocardial fibrosis and oxidative stress. The expression of angiopoietin-1 in the heart was significantly increased by pitavastatin at 6 weeks after TAC.. Pitavastatin has preventive effects on the progression of heart failure even in the hypertrophied heart.

Topics: Angiopoietin-1; Animals; Blood Pressure; Fibrosis; Gene Expression Regulation; Heart Failure; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypertrophy, Left Ventricular; Mice; Myocardium; Neovascularization, Pathologic; Oxidative Stress; Quinolines; Time Factors

The aim of this prospective study was to determine whether statin therapy (pitavastatin) has a beneficial effect on the prevention of new-onset atrial fibrillation (AF) in elderly patients with hypertension (HTN) and to evaluate the relationships among statin treatment, the development of AF, and left atrial (LA) and ventricular (LV) structure and function.. We enrolled eligible elderly patients (≥65 years old) with HTN and LV hypertrophy until the number of patients reached 110 in both groups. The 110 patients with HTN who needed statin therapy (HTN with statin group) were started on pitavastatin (1-2 mg/day), and both groups continued with appropriate medication for HTN. LV and LA structure and function were examined by conventional and speckle-tracking echocardiography at baseline and after 1 year. LA volume and function in the HTN with statin group improved more than in the HTN without statin group. There was a significant difference in survival free of new-onset AF in the patients with and without statin therapy during the 2-year follow-up (hazard ratio: 0.32, P=0.027).. Pitavastatin had a beneficial effect on LV diastolic function and LA structure and function in elderly patients with HTN. Pitavastatin treatment may be associated with a lower incidence of new-onset AF.

Topics: Age Factors; Aged; Aged, 80 and over; Atrial Fibrillation; Atrial Function, Left; Chi-Square Distribution; Disease-Free Survival; Dyslipidemias; Electrocardiography; Female; Follow-Up Studies; Heart Atria; Heart Ventricles; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypertension; Hypertrophy, Left Ventricular; Japan; Kaplan-Meier Estimate; Male; Multivariate Analysis; Proportional Hazards Models; Prospective Studies; Quinolines; Stroke Volume; Time Factors; Treatment Outcome; Ultrasonography; Ventricular Dysfunction, Left; Ventricular Function, Left

Angiotensin II (Ang II) plays a pivotal role in cardiovascular remodeling leading to hypertension, myocardial infarction, and stroke. Pitavastatin, an HMG-CoA reductase inihibitor, is known to have pleiotropic actions against the development of cardiovascular remodeling. The objectives of this study were to clarify the beneficial effects as well as the mechanism of action of pitavastatin against Ang II-induced organ damage. C57BL6/J mice at 10 weeks of age were infused with Ang II for 2 weeks and were simultaneously administered pitavastatin or a vehicle. Pitavastatin treatment improved Ang II-induced left ventricular hypertrophy and diastolic dysfunction and attenuated enhancement of cardiac fibrosis, cardiomyocyte hypertrophy, coronary perivascular fibrosis, and medial thickening. Ang II-induced oxidative stress, cardiac TGFbeta-1 expression, and Smad 2/3 phosphorylation were all attenuated by pitavastatin treatment. Pitavastatin also reduced Ang II-induced cardiac remodeling and diastolic dysfunction in eNOS-/- mice as in wild-type mice. In eNOS-/- mice, the Ang II-induced cardiac oxidative stress and TGF-beta-Smad 2/3 signaling pathway were enhanced, and pitavastatin treatment attenuated the enhanced oxidative stress and the signaling pathway. Moreover, pitavastatin treatment reduced the high mortality rate and improved renal insufficiency in Ang II-treated eNOS-/- mice, with suppression of glomerular oxidative stress and TGF-beta-Smad 2/3 signaling pathway. In conclusion, pitavastatin exerts eNOS-independent protective actions against Ang II-induced cardiovascular remodeling and renal insufficiency through inhibition of the TGF-beta-Smad 2/3 signaling pathway by suppression of oxidative stress.

Topics: Angiotensin II; Animals; Cardiotonic Agents; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypertrophy, Left Ventricular; Mice; Mice, Inbred C57BL; Mice, Knockout; Nitric Oxide Synthase Type III; Oxidative Stress; Quinolines; Renal Insufficiency; Signal Transduction; Smad2 Protein; Smad3 Protein; Transforming Growth Factor beta; Ventricular Remodeling

Statin therapy may be associated with lower mortality in patients with heart failure, but the underlying mechanism of such an association is unknown. We have evaluated the effects of pitavastatin on cardiac function and survival in a rat model of hypertensive heart failure and investigated the molecular mechanism of the observed effects. Dahl salt-sensitive rats fed with high-salt diet from 7 weeks of age developed compensatory left ventricular hypertrophy at 12 weeks and heart failure at 19 weeks. Dahl salt-sensitive rats were treated with either vehicle or pitavastatin (0.3 mg/kg per day) from 7 or 12 weeks. Both early-onset and late-onset pitavastatin treatment reduced left ventricular fibrosis, improved cardiac function, and increased the survival rate apparent at 19 weeks. The increases in the expression levels of hypertrophic, profibrotic, and metalloproteinase genes as well as in gelatinase activities in the heart induced by the high-salt diet were suppressed by pitavastatin treatment. Furthermore, the level of cardiac endothelin-1 was increased in association with the development of heart failure in a manner sensitive to treatment with pitavastatin. Both early and late pitavastatin treatment thus improved cardiac function and survival, with modulation of extracellular matrix remodeling and endothelin-1 signaling possibly contributing to these beneficial effects.

Topics: Animals; Blood Pressure; Cardiac Output, Low; Disease Models, Animal; Endothelin-1; Extracellular Matrix; Gene Expression; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypertension; Hypertrophy, Left Ventricular; Lipids; Male; Matrix Metalloproteinases; Protein Prenylation; Quinolines; Rats; Rats, Inbred Dahl; Receptors, Endothelin; Renin-Angiotensin System; Survival Rate; Tissue Inhibitor of Metalloproteinases; Ventricular Remodeling

1. Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase (statins) manifest pleiotropic effects that may contribute to their therapeutic efficacy. However, the mechanism of the beneficial action of statins on cardiac hypertrophy and fibrosis remains unclear. We have now investigated this action of pitavastatin in Dahl salt-sensitive (DS) rats. 2. The DS rats progressively develop marked hypertension when fed a diet containing 8% NaCl from 7 weeks of age. These animals exhibited pronounced cardiac hypertrophy and fibrosis, as well as upregulation of fetal-type cardiac gene expression at 12 weeks of age, compared with DS rats fed a diet containing 0.3% NaCl. The abundance of mRNAs for collagen types I and III, angiotensin-converting enzyme, transforming growth factor-beta1 and connective tissue growth factor was also increased in the heart of rats on the high-salt diet. 3. Treatment of rats on the high-salt diet with a non-antihypertensive dose of pitavastatin (0.3 or 1 mg/kg per day) from 7 to 12 weeks of age attenuated the development of cardiac hypertrophy and fibrosis, as well as inhibiting the upregulation of cardiac gene expression. Pitavastatin also blocked the translocation of RhoA to the membrane fraction of the left ventricle and RhoA activation, as well as the phosphorylation of the mitogen-activated protein kinases extracellular signal-regulated kinase (ERK)-1 and ERK-2 and an increase in the DNA binding activity of serum response factor (SRF) in the heart induced by the high-salt diet. 4. These findings suggest that the effects of pitavastatin on load-induced cardiac hypertrophy and fibrosis are independent of its cholesterol-lowering action and may be mediated, at least in part, through inhibition of RhoA-ERK-SRF signalling.

Topics: Aging; Animals; Blood Pressure; Body Weight; Cardiomegaly; Collagen; Electrophoretic Mobility Shift Assay; Extracellular Signal-Regulated MAP Kinases; Fibrosis; Gene Expression; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypertension; Hypertrophy, Left Ventricular; Immunoblotting; Lipids; Male; Myocardium; Quinolines; Rats; Rats, Inbred Dahl; rhoA GTP-Binding Protein; Signal Transduction; Sodium Chloride