Accumulating evidence indicates alteration of the β-adrenoceptor (AR), such as desensitization and subtype switching of its coupling G protein, plays a role in the protection against catecholamine toxicity in heart failure. However, in human takotsubo syndrome (TTS), which is associated with a surge of circulating catecholamine in the acute phase, there is no histologic evidence of β-AR alteration. The purpose of this study was to investigate the involvement of alteration of β-AR signaling in the mechanism of TTS development. Left ventricular (LV) biopsied samples from 26 patients with TTS, 19 with normal LV function, and 26 with dilated cardiomyopathy (DCM) were studied. G protein-coupled receptor kinase 2 (GRK2) and β-arrestin2, which initiate the alteration of β-AR signaling, were more abundantly expressed in the myocardium in acute-phase TTS than in those of DCM and normal control as indicated by immunohistochemistry. The percentage of cardiomyocytes that showed positive membrane staining for GRK2 and β-arrestin2 was also significantly higher in acute-phase TTS. Sequential biopsies in the recovery-phase for two patients with TTS revealed that membrane expression of GRK2 and β-arrestin2 faded over time. This study provided the first histologic evidence of the involvement of alteration of β-ARs in the development of TTS.

The energy spacing between the ground-state spin doublet of 4 Λ He(1 + ,0 + ) was determined to be 1406 ± 2 ± 2 keV, by measuring γ rays for the 1 + → 0 + transition with a high efficiency germanium detector array in coincidence with the 4 He(K − , π − ) 4Λ He reaction at J-PARC. In comparison to the corresponding energy spacing in the mirror hypernucleus 4 Λ H, the present result clearly indicates the existence of charge symmetry breaking (CSB) in ΛN interaction. It is also found that the CSB effect is large in the 0 + ground state but is by one order of magnitude smaller in the 1 + excited state, demonstrating that the ΛN CSB interaction has spin dependence.

Abstract-Soluble fms-like tyrosine kinase-1 (sFlt-1), an endogenous inhibitor of vascular endothelial growth factor and placental growth factor, is involved in the pathogenesis of cardiovascular disease. However, the significance of sFlt-1 in heart failure has not been fully elucidated. We found that sFlt-1 is decreased in renal failure and serves as a key molecule in atherosclerosis. In this study, we aimed to investigate the role of the decreased sFlt-1 production in heart failure, using sFlt-1 knockout mice. sFlt-1 knockout mice and wild-type mice were subjected to transverse aortic constriction and evaluated after 7 days. The sFlt-1 knockout mice had significantly higher mortality (52% versus 15%; P=0.0002) attributable to heart failure and showed greater cardiac hypertrophy (heart weight to body weight ratio, 8.95±0.45 mg/g in sFlt-1 knockout mice versus 6.60±0.32 mg/g in wild-type mice; P<0.0001) and cardiac dysfunction, which was accompanied by a significant increase in macrophage infiltration and cardiac fibrosis, than wild-type mice after transverse aortic constriction. An anti-placental growth factor-neutralizing antibody prevented pressure overload-induced cardiac hypertrophy, fibrosis, and cardiac dysfunction. Moreover, monocyte chemoattractant protein-1 expression was significantly increased in the hypertrophied hearts of sFlt-1 knockout mice compared with wild-type mice. Monocyte chemoattractant protein-1 inhibition with neutralizing antibody ameliorated maladaptive cardiac remodeling in sFlt-1 knockout mice after transverse aortic constriction. In conclusion, decreased sFlt-1 production plays a key role in the aggravation of cardiac hypertrophy and heart failure through upregulation of monocyte chemoattractant protein-1 expression in pressure-overloaded heart. Correspondence to Yoshihiko Saito, First Department of Internal Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara, 634-8522, Japan. E-mail saitonaramed@gmail.com Suppressed Production of Soluble Fms-Like Tyrosine Kinase-1 Contributes to MyocardialRemodeling and Heart Failure Ayako Seno, Yukiji Takeda, Masaru Matsui, Aya Okuda, Tomoya Nakano, Yasuki Nakada, Takuya Kumazawa, Hitoshi Nakagawa, Taku Nishida, Kenji Onoue, Satoshi Somekawa, Makoto Watanabe, Hiroyuki Kawata, Rika Kawakami, Hiroyuki Okura, Shiro Uemura, Yoshihiko Saito © 2016 American Heart Association, Inc. function in patients with acute coronary syndrome. 6 Therefore, it seems that insufficient sFlt-1 production is associated with adverse cardiovascular outcomes.On the contrary, several previous reports have shown that upregulation of sFlt-1 contributes to the development of heart failure, with antiangiogenesis activity by binding to VEGF. 7,8 In clinical settings, plasma levels of sFlt-1 are not only directly correlated with the severity of heart failure but also strongly associated with poor outcomes in patients with heart failure.9,10 These observations provide a plausible interpretation that increased sFlt-1 production aggravates heart failure with adverse car...

The heart utilizes multiple adaptive mechanisms to maintain pump function. Compensatory cardiac hypertrophy reduces wall stress and oxygen consumption, thereby protecting the heart against acute blood pressure elevation. The nuclear effector of the Hippo pathway, Yes-associated protein 1 (YAP), is activated and mediates compensatory cardiac hypertrophy in response to acute pressure overload (PO). In this study, YAP promoted glycolysis by upregulating glucose transporter 1 (GLUT1), which in turn caused accumulation of intermediates and metabolites of the glycolytic, auxiliary, and anaplerotic pathways during acute PO. Cardiac hypertrophy was inhibited and heart failure was exacerbated in mice with YAP haploinsufficiency in the presence of acute PO. However, normalization of GLUT1 rescued the detrimental phenotype. PO induced accumulation of glycolytic metabolites, including L-serine, L-aspartate, and malate, in a YAP-dependent manner, thereby promoting cardiac hypertrophy. YAP upregulated the GLUT1 gene through interaction with TEAD1 and HIF-1α in cardiomyocytes. Thus, YAP induces compensatory cardiac hypertrophy through activation of the Warburg effect.

Aims A diet with modified components, such as a ketogenic low-carbohydrate (LC) diet, potentially extends longevity and healthspan. However, how a LC diet impacts on cardiac pathology during hemodynamic stress remains elusive. This study evaluated the effects of a LC diet high in either fat (Fat-LC) or protein (Pro-LC) in a mouse model of chronic hypertensive cardiac remodeling. Methods and Results Wild-type mice were subjected to transverse aortic constriction, followed by feeding with the Fat-LC, the Pro-LC, or a high-carbohydrate control diet. After 4 weeks, echocardiographic, hemodynamic, histological and biochemical analyses were performed. LC diet consumption after pressure overload inhibited the development of pathological hypertrophy and systolic dysfunction compared to the control diet. An anti-hypertrophic serine/threonine kinase, GSK-3β, was re-activated by both LC diets; however, the Fat-LC, but not the Pro-LC, diet exerted cardioprotection in GSK-3β cardiac-specific knockout mice. β-hydroxybutyrate, a major ketone body in mammals, was increased in the hearts of mice fed the Fat-LC, but not the Pro-LC, diet. In cardiomyocytes, ketone body supplementation inhibited phenylephrine-induced hypertrophy, in part by suppressing mTOR signaling. Conclusions Strict carbohydrate restriction suppresses pathological cardiac growth and heart failure after pressure overload through distinct anti-hypertrophic mechanisms elicited by supplemented macronutrients. Translational Perspective Hemodynamic stress, such as hypertension, induces pathological cardiac hypertrophy, leading to heart failure. There is growing evidence that modulating components of diet affects cardiac function in humans, although the causality and underlying mechanisms are poorly understood. Our study demonstrates that strict restriction of dietary carbohydrates supplemented with either fat or proteins during acute hemodynamic stress attenuates the development and progression of cardiac hypertrophy and heart failure by activating distinct anti-hypertrophic and cardioprotective signaling mechanisms. The study suggests that it would be useful to investigate the therapeutic benefit of carbohydrate restriction in patients with hypertension and cardiac hypertrophy in clinical studies.

Y. Sex differences in clinical characteristics and long-term outcome in acute decompensated heart failure patients with preserved and reduced ejection fraction. Am J Physiol Heart Circ Physiol 310: H813-H820, 2016. First published January 8, 2016 doi:10.1152/ajpheart.00602.2015.-In patients with acute decompensated heart failure (ADHF), sex differences considering clinical and pathophysiologic features are not fully understood. We investigated sex differences in left ventricular (LV) ejection fraction (LVEF), plasma B-type natriuretic peptide (BNP) levels, and prognostic factors in patients with ADHF in Japan. We studied 748 consecutive ADHF patients of 821 patients registered in the ADHF registry between January 2007 and December 2014. Patients were divided into four groups based on sex and LVEF [reduced (ejection fraction, or EF, Ͻ50%, heart failure with reduced EF, or HFrEF) or preserved (EF Ն50%, heart failure with preserved LVEF, or HFpEF)]. The primary endpoint was the combination of cardiovascular death and heart failure (HF) admission. The present study consisted of 311 female patients (50% HFrEF, 50% HFpEF) and 437 male patients (63% HFrEF, 37% HFpEF). There was significant difference between sexes in the LVEF distribution profile. The ratio of HFpEF patients was significantly higher in female patients than in male patients (P ϭ 0.0004). Although there were no significant sex differences in median plasma BNP levels, the prognostic value of BNP levels was different between sexes. Kaplan-Meier analysis revealed that the high BNP group had worse prognosis than the low BNP group in male but not in female patients. In multivariate analysis, log transformed BNP at discharge predicted cardiovascular events in male but not in female HF patients (female, hazard ratio: 1.169; 95% confidence interval: 0.981-1.399; P ϭ 0.0806; male, hazard ratio: 1.289; 95% confidence interval: 1.120 -1.481; P ϭ 0.0004). In patients with ADHF, the distribution of LV function and the prognostic significance of plasma BNP levels for long-term outcome were different between the sexes. acute decompensated heart failure; B-type natriuretic peptide; sex differences; preserved ejection fraction

No abstract

Aims Well-controlled mitochondrial homeostasis, including a mitochondria-specific form of autophagy (hereafter referred to as mitophagy), is essential for maintaining cardiac function. The molecular mechanism mediating mitophagy during PO is poorly understood. We have shown previously that mitophagy in the heart is mediated primarily by Atg5/Atg7-independent mechanisms, including Unc-51-like kinase1 (Ulk1)-dependent alternative mitophagy, during myocardial ischemia. Here, we investigated the role of alternative mitophagy in the heart during PO-induced hypertrophy. Methods and Results Mitophagy was observed in the heart in response to transverse aortic constriction (TAC), peaking at 3-5 days. Whereas mitophagy is transiently upregulated by TAC through an Atg7-dependent mechanism in the heart, peaking at 1 day, it is also activated more strongly and with a delayed time course through an Ulk1-dependent mechanism. TAC induced more severe cardiac dysfunction, hypertrophy and fibrosis in ulk1 cardiac specific knock-out (cKO) mice than in wild type mice. Delayed activation of mitophagy was characterized by the co-localization of Rab9 dots and mitochondria and phosphorylation of Rab9 at Ser179, major features of alternative mitophagy. Furthermore, TAC-induced decreases in the mitochondrial aspect ratio were abolished and the irregularity of mitochondrial cristae was exacerbated, suggesting that mitochondrial quality control mechanisms are impaired in ulk1 cKO mice in response to TAC. TAT-Beclin 1 activates mitophagy even in Ulk1-deficient conditions. TAT-Beclin 1 treatment rescued mitochondrial dysfunction and cardiac dysfunction in ulk1 cKO mice during PO. Conclusions Ulk1-mediated alternative mitophagy is a major mechanism mediating mitophagy in response to PO and plays an important role in mediating mitochondrial quality control mechanisms and protecting the heart against cardiac dysfunction. Translational perspective Heart failure is often accompanied by mitochondrial dysfunction in cardiomyocytes. Elimination of dysfunctional mitochondria by mitochondria-specific forms of autophagy, termed mitophagy, is a crucial mechanism for maintaining mitochondrial function in the stressed heart. We discovered that an unconventional form of mitophagy mediated through an Atg7-independent and Ulk1- and Rab9-dependent mechanism is a predominant form of mitophagy in the heart in response to pressure overload. Interventions to restore mitophagy by stimulating the signaling mechanism of the Ulk1-Rab9-dependent mitophagy should delay the development of heart failure in patients with increased afterload.