Takayuki Ise

Pitavastatin, an HMG-CoA Reductase Inhibitor, Exerts eNOS-Independent Protective Actions Against Angiotensin II–Induced Cardiovascular Remodeling and Renal Insufficiency

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 TGFβ-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-β–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-β-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-β-Smad 2/3 signaling pathway by suppression of oxidative stress.

Extensive late gadolinium enhancement on cardiovascular magnetic resonance predicts adverse outcomes and lack of improvement in LV function after steroid therapy in cardiac sarcoidosis

Background Gadolinium-enhanced cardiovascular magnetic resonance is an emerging tool for the diagnosis of cardiac sarcoidosis (CS); however, the correlations between extent of late gadolinium enhancement (LGE) and efficacy of steroid therapy and adverse outcomes in patients with CS remain unclear. Objective We aimed to clarify the prognostic impact of extent of LGE in patients with CS. Methods Before the start of steroid therapy, 43 consecutive LGE-positive patients with CS were divided into two groups based on the extent of LGE by a median value: small-extent LGE (LGE mass <20% of LV mass; n=21) and large-extent LGE (LGE mass ≥20% of LV mass; n=22). We examined the correlations between extent of LGE and outcomes after steroid therapy. Results Among the 6 patients who died from heart disorders, 11 patients who were hospitalised because of heart failure and 6 patients who suffered life-threatening arrhythmia during the follow-up period, large-extent LGE predicted higher incidences of cardiac mortality and hospitalisation for heart failure. Multivariate Cox regression analysis showed that large-extent LGE was independently associated with combined adverse outcomes including cardiac death, hospitalisation for heart failure, and life-threatening arrhythmias. In the small-extent LGE group, LV end-diastolic volume index significantly decreased and LVEF significantly increased after steroid therapy, whereas in the large-extent LGE group, neither LV volume nor LVEF changed substantially. Conclusions Large-extent LGE correlates with absence of LV functional improvement and high incidence of adverse outcomes in patients with CS after steroid therapy.

Androgen-androgen receptor system protects against angiotensin II-induced vascular remodeling.

Age-related andropause promotes cardiovascular disease in males. Although we had previously reported that the androgen-androgen receptor (AR) system plays important roles in cardiac growth and remodeling, the systems involvement in vascular remodeling remains unclear. To clarify this role, 25-wk-old male AR knockout (ARKO) mice and littermate male wild-type (WT) mice were divided into two groups with and without angiotensin II (Ang II) administration (2.0 mg/kg . d) for 14 d, respectively. No morphological differences in the coronary artery and thoracic aorta were observed between the groups without Ang II. Ang II stimulation markedly increased medial thickness and perivascular fibrosis in ARKO mice, with enhanced TGF-beta1, collagen type I, and collagen type III gene expression in the aorta. Ang II stimulation also prominently increased superoxide production, lipid peroxidation, and gene expression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase components in ARKO mice compared with WT mice. In addition, phosphorylation of c-Jun N-terminal kinase (JNK) and phosphorylated (Smad2/3) was remarkably enhanced in Ang II-treated ARKO mice compared with Ang II-treated WT mice. Notably, daily urinary nitric oxide (NO) metabolites excretion as a marker of NO bioavailability, aortic endothelial NO synthase expression and phosphorylation, and Akt phosphorylation were significantly reduced in ARKO mice compared with WT mice, regardless of Ang II stimulation. In conclusion, the androgen-AR system is required for the preservation of NO bioavailability through Akt-endothelial NO synthase system activation and exerts protective effects against Ang II-induced vascular remodeling by regulating oxidative stress, c-Jun N-terminal kinase (JNK) signaling, and the TGF-beta-phosphorylated Smad pathway.

Adaptive Servo-Ventilation Therapy for Patients With Chronic Heart Failure in a Confirmatory, Multicenter, Randomized, Controlled Study

BACKGROUND Adaptive servo-ventilation (ASV) therapy is expected to be novel nonpharmacotherapy with hemodynamic effects on patients with chronic heart failure (CHF), but sufficient evidence has not been obtained. METHODS AND RESULTS A 24-week, open-label, randomized, controlled study was performed to confirm the cardiac function-improving effect of ASV therapy on CHF patients. At 39 institutions, 213 outpatients with CHF, whose left ventricular ejection fraction (LVEF) was <40% and who had mild to severe symptoms [New York Heart Association (NYHA) class: ≥II], were enrolled. After excluding 8 patients, 102 and 103 underwent ASV plus guideline-directed medical therapy (GDMT) [ASV group] and GDMT only [control group], respectively. The primary endpoint was LVEF, and the secondary endpoints were HF deterioration, B-type natriuretic peptide (BNP), and clinical composite response (CCR: NYHA class+HF deterioration). LVEF and BNP improved significantly at completion against the baseline values in the 2 groups. However, no significant difference was found between these groups. HF deterioration tended to be suppressed. The ASV group showed a significant improvement in CCR corroborated by significant improvements in NYHA class and ADL against the control group. CONCLUSIONS Under the present studys conditions, ASV therapy was not superior to GDMT in the cardiac function-improving effect but showed a clinical status-improving effect, thus indicating a given level of clinical benefit.

Effects of the Addition of Eicosapentaenoic Acid to Strong Statin Therapy on Inflammatory Cytokines and Coronary Plaque Components Assessed by Integrated Backscatter Intravascular Ultrasound

BACKGROUND The effects of eicosapentaenoic acid (EPA) on coronary artery disease have been previously reported; however, those of the addition of EPA to strong statins on coronary plaque components and local inflammatory cytokines are not known. METHODSANDRESULTS A total of 95 patients who had been treated with strong statin for at least 6 months were randomized into 2 groups: an EPA group (additional treatment with EPA at 1,800 mg/day, n=48) or a control group (no additional treatment, n=47), for 6 months. The tissue characteristics of target coronary plaque in each patient were analyzed using IB-IVUS before and after treatment. We also measured plasma levels of inflammatory cytokines sampled in the coronary sinus (CS) and peripheral vein.A significant reduction in lipid volume (18.5 ± 1.3 to 15.0 ± 1.5 mm(3), P=0.007) and a significant increase in fibrous volume (22.9 ± 0.8 to 25.6 ± 1.1 mm(3), P=0.01) were observed in IB-IVUS image analyses in the EPA group, but no significant changes in the plaque components in the control group. CS levels of pentraxin 3 and monocyte chemoattractant protein-1 were lower after than before treatment with EPA (3.3 ± 2.1 to 2.6 ± 1.2 ng/ml, 120.4 ± 26.2 to 110.2 ± 26.8 pg/ml, P=0.015 and P=0.008, respectively); however, there were no significant changes in those inflammatory cytokines between pre- and post-treatment in the control group. CONCLUSIONS The addition of EPA was associated with reduced lipid volume in coronary plaques and decreased inflammatory cytokines.

Androgen Receptor Promotes Sex-Independent Angiogenesis in Response to Ischemia and Is Required for Activation of Vascular Endothelial Growth Factor Receptor Signaling

Background— Hypoandrogenemia is associated with an increased risk of ischemic diseases. Because actions of androgens are exerted through androgen receptor (AR) activation, we studied hind-limb ischemia in AR knockout mice to elucidate the role of AR in response to ischemia. Methods and Results— Both male and female AR knockout mice exhibited impaired blood flow recovery, more cellular apoptosis, and a higher incidence of autoamputation after ischemia. In ex vivo and in vivo angiogenesis studies, AR-deficient vascular endothelial cells showed reduced angiogenic capability. In ischemic limbs of AR knockout mice, reductions in the phosphorylation of the Akt protein kinase and endothelial nitric oxide synthase were observed despite a robust increase in hypoxia-inducible factor 1&agr; and vascular endothelial cell growth factor (VEGF) gene expression. In in vitro studies, siRNA-mediated ablation of AR in vascular endothelial cells blunted VEGF-stimulated phosphorylation of Akt and endothelial nitric oxide synthase. Immunoprecipitation experiments documented an association between AR and kinase insert domain protein receptor that promoted the recruitment of downstream signaling components. Conclusions— These results document a physiological role of AR in sex-independent angiogenic potency and provide evidence of novel cross-talk between the androgen/AR signaling and VEGF/kinase insert domain protein receptor signaling pathways.

Heparin Cofactor II Protects Against Angiotensin II-Induced Cardiac Remodeling Via Attenuation of Oxidative Stress in Mice

Heparin cofactor II (HCII), a serine protease inhibitor, inhibits tissue thrombin action after binding with dermatan sulfate proteoglycans in the extracellular matrix of the vascular system. We previously reported that heterozygous HCII-deficient (HCII+/−) humans and mice demonstrate acceleration of vascular remodeling, including atherosclerosis. However, the action of HCII on cardiac remodeling never has been determined. HCII+/+ and HCII+/− mice at age 25 weeks were infused with angiotensin II (Ang II; 2.0 mg/kg/d) for 2 weeks by an osmotic mini-pump. Echocardiography revealed acceleration of cardiac concentric remodeling in HCII+/− mice and larger left atrial volume in HCII+/− mice than in HCII+/+ mice. Histopathologic studies showed more prominent interstitial fibrosis in both the left atrium and left ventricle in HCII+/− mice than in HCII+/+ mice. Daily urinary excretion of 8-hydroxy-2′-deoxyguanosine, a parameter of oxidative stress, and dihydroethidium-positive spots, indicating superoxide production in the myocardium, were markedly increased in Ang II-treated HCII+/− mice compared to those in HCII+/+ mice. Cardiac gene expression levels of atrial natriuretic peptides and brain natriuretic peptides, members of the natriuretic peptide family, Nox 4, Rac-1, and p67phox as components of NAD(P)H oxidase, and transforming growth factor-&bgr;1 and procollagen III were more augmented in HCII+/− mice than in HCII+/+ mice. However, administration of human HCII protein attenuated all of those abnormalities in Ang II-treated HCII+/− mice. Moreover, human HCII protein supplementation almost abolished cardiac fibrosis in Ang II-treated HCII+/+ mice. The results indicate that HCII has a protective role against Ang II-induced cardiac remodeling through suppression of the NAD(P)H oxidase-transforming growth factor-&bgr;1 pathway.

Androgen Receptor Promotes Gender-Independent Angiogenesis in Response to Ischemia and is Required for Activation of VEGF Receptor Signaling

Background— Hypoandrogenemia is associated with an increased risk of ischemic diseases. Because actions of androgens are exerted through androgen receptor (AR) activation, we studied hind-limb ischemia in AR knockout mice to elucidate the role of AR in response to ischemia. Methods and Results— Both male and female AR knockout mice exhibited impaired blood flow recovery, more cellular apoptosis, and a higher incidence of autoamputation after ischemia. In ex vivo and in vivo angiogenesis studies, AR-deficient vascular endothelial cells showed reduced angiogenic capability. In ischemic limbs of AR knockout mice, reductions in the phosphorylation of the Akt protein kinase and endothelial nitric oxide synthase were observed despite a robust increase in hypoxia-inducible factor 1&agr; and vascular endothelial cell growth factor (VEGF) gene expression. In in vitro studies, siRNA-mediated ablation of AR in vascular endothelial cells blunted VEGF-stimulated phosphorylation of Akt and endothelial nitric oxide synthase. Immunoprecipitation experiments documented an association between AR and kinase insert domain protein receptor that promoted the recruitment of downstream signaling components. Conclusions— These results document a physiological role of AR in sex-independent angiogenic potency and provide evidence of novel cross-talk between the androgen/AR signaling and VEGF/kinase insert domain protein receptor signaling pathways.

Effects of Docosahexaenoic Acid on the Endothelial Function in Patients with Coronary Artery Disease

AIM The consumption of n-3 polyunsaturated fatty acids (PUFA), including docosahexaenoic acid DHA), reduces the incidence of cardiovascular events, and reduced serum levels of n-3 PUFA may be associated with an increased risk of cardiovascular events. However, controversy remains regarding which components of PUFA are associated with the endothelial function in patients with coronary artery disease (CAD). We therefore examined the associations between the n-3 and n-6 PUFA levels and CAD. METHODS We retrospectively reviewed 160 consecutive Japanese patients with CAD whose endothelial function was measured according to the percent change in flow-mediated dilation (FMD) and the serum levels of n-3 PUFA, including eicosapentaenoic acid (EPA) and DHA, and n-6 PUFA, including arachidonic acid (AA) and dihomo-gamma-linolenic acid (DHLA). RESULTS A single regression analysis showed no relationships between the FMD and the serum levels of PUFA, including EPA, DHA, AA and DHLA. In contrast, a multiple regression analysis showed that the DHA level was a positive (＜ 0.01) and age was a negative (P ＜ 0.001) contributor to an increased FMD; however, sex, body mass index, systolic and diastolic blood pressure, current/past smoking and the levels of HbA1c, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, EPA, AA and DHLA did not significantly affect the outcome. CONCLUSIONS The serum level of DHA is associated with the endothelial function evaluated according to the FMD in patients with CAD, thus suggesting that a low serum level of DHA may be a predictive biomarker for endothelial dysfunction.

Expression of NLRP3 in subcutaneous adipose tissue is associated with coronary atherosclerosis

OBJECTIVES The promotion of adipose tissue inflammation by lifestyle-related diseases such as obesity and diabetes accelerates atherogenesis; however, the underlying mechanisms remain incompletely understood. Nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3) inflammasome contributes to chronic inflammation in adipose tissue. Here, we investigated the link between NLRP3 expression in subcutaneous adipose tissue (SAT) and the severity of coronary atherosclerosis. METHODS AND RESULTS SAT was obtained from 72 patients who underwent heart device implantation and coronary angiography. Expression of NLRP3 inflammasome-related molecules (NLRP3, IL-1β and IL-18) in SAT were evaluated by quantitative RT-PCR. Laboratory markers related to lifestyle-related diseases were measured. Patients with obesity, dyslipidemia (P < 0.05, respectively), diabetes or hyperuricemia (P < 0.01, respectively) had significantly higher expression of NLRP3. Multivariate analysis demonstrated that body mass index and serum level of uric acid were predictors of NLRP3 expression in SAT. The expression of NLRP3 in SAT correlated negatively with serum adiponectin level (r = -0.23, P < 0.05). Patients with coronary artery disease showed higher NLRP3 expression than patients without significant stenosis (P < 0.01). Furthermore, the expression of NLRP3 in SAT correlated positively with the severity of coronary atherosclerosis as determined by Gensini score (r = 0.47, P < 0.0001) or SYNTAX score (r = 0.55, P < 0.0001). Multiple regression analysis revealed that the expression of NLRP3 in SAT remains as an independent predictors for the severity of coronary atherosclerosis. CONCLUSIONS The expression of NLRP3 in SAT, which is affected by lifestyle-related diseases, is associated with the severity of coronary atherosclerosis. Our results suggest that NLRP3 inflammasome in SAT may have a role in atherogenesis.