Metabolic surgery in improving arterial health in obese individuals

PURPOSE

Arterial stiffness has gained recognition as a stand-alone risk factor for cardiovascular disease (CVD). Obesity is intricately linked to elevated arterial stiffness, the development of left ventricular (LV) hypertrophy, and the emergence of diastolic dysfunction, all of which collectively contribute substantially to an unfavorable prognosis. Weight loss has become a standard recommendation for all patients with CVD concurrent with morbid obesity; however, randomized evidence to support this recommendation was limited earlier. The latest scientific studies revealed dynamic changes in aortic stiffness after substantial weight loss by bariatric surgery, also known as metabolic surgery, in patients with obesity. There is also a favorable evolution in LV hypertrophy and a significant impact on arterial hypertension and other promising cardiovascular outcomes in obese people after bariatric surgery.

METHODS/RESULTS

We aimed to examine the cardiovascular effects of various metabolic surgeries in morbidly obese individuals, especially their role in improving arterial health, the potential impact on surrogate markers of atherosclerotic vascular disease, and consequently reducing the likelihood of cardiovascular events.

CONCLUSION

In conclusion, metabolic surgery is associated with a significant decrease in the occurrence of major adverse cardiovascular events (MACE) and all-cause mortality among obese individuals, alongside remarkable enhancement of arterial health. These findings underscore the critical importance of implementing strategies to combat obesity and reduce adiposity within the general population.

Beta-blockers in Hypertensive Left Ventricular Hypertrophy and Atrial Fibrillation Prevention

BACKGROUND

Hypertensive left ventricular hypertrophy (HTN LVH) is a key risk factor for atrial fibrillation (AF).

OBJECTIVE

To evaluate the possible role of beta-blockers (BBs) in addition to a renin-angiotensinaldosterone system (RAAS) blocker in AF prevention in patients with HTN LVH.

METHODS

We performed a PubMed, Elsevier, SAGE, Oxford, and Google Scholar search with the search items 'beta blocker hypertension left ventricular hypertrophy patient' from 2013-2023. In the end, a 'snowball search', based on the references of relevant papers as well as from papers that cited them was performed.

RESULTS

HTN LVH is a risk factor for AF. In turn, AF substantially complicates HTN LVH and contributes to the genesis of heart failure (HF) with preserved ejection fraction (HFpEF). The prognosis of HFpEF is comparable with that of HF with reduced EF (HFrEF), and, regardless of the type, HF is associated with five-year mortality of 50-75%. The antiarrhythmic properties of BBs are wellrecognized, and BBs as a class of drugs are - in general - recommended to decrease the incidence of AF in HTN.

CONCLUSION

BBs are recommended (as a class) for AF prevention in several contemporary guidelines for HTN. LVH regression in HTN - used as a single criterion for the choice of antihypertensive medication - does not capture this protective effect. Consequently, it is worth studying how meaningful this antiarrhythmic action (to prevent AF) of BBs is in patients with HTN LVH in addition to a RAAS blocker.

The Prevention of the New Onset of Heart Failure in Hypertensive Patients

In 2014, Japan was estimated to have approximately 27 million patients with hypertension (HT), and the ultimate goal of treatment is to prevent complications of HT, including heart failure (HF). The major structural changes in the heart that cause HF are left ventricular (LV) hypertrophy (LVH) and the resulting LV diastolic dysfunction. However, in patients with HT with well-controlled blood pressure (BP), whether they are in HF stage A (only HT) or B (with organic heart disease) is often unclear. It has been reported that strict BP control suppresses LVH, and the improvement of LVH leads to the suppression of cardiovascular complications. Thus, detecting HF stage B HT and providing appropriate treatment lead to the suppression of HF onset. This review focuses on the detection and treatment of organic heart disease in HT.

Complexation of the Antihypertensive Drug Olmesartan with Zn: In Vivo Antihypertensive and Cardiac Effects

This study is based on the premise that the application of chemical synthesis strategies to structurally modify commercial drugs by complexation with biometals is a valid procedure to improve their biological effects. Our purpose is to synthesize a compound with greater efficacy than the original drug, able to enhance its antihypertensive and cardiac pharmacological activity. Herein, the structure of the coordination compound of Zn(II) and the antihypertensive drug olmesartan, [Zn(Olme)(H2O)2] (ZnOlme), is presented. After 8 weeks of treatment in SHR male rats, ZnOlme displayed a better blood pressure-lowering activity compared with olmesartan, with a noticeable effect even in the first weeks of treatment, while ZnCl2 showed similar results than the control. ZnOlme also reduced left ventricle (LV) weight and left ventricle/tibia length ratio (LV/TL), posterior wall thickness (PWT), and intraventricular septum in diastole (IVSd) suggesting its potential to prevent LV hypertrophy. Besides, ZnOlme reduced interstitial fibrosis (contents of collagen types I and III, responsible for giving rigidity and promoting vascular elasticity, respectively). The recovery of heart function was also evidenced by fractional shortening (diastolic left ventricular/systolic left ventricular) diameter determinations. Furthermore, ZnOlme increased the antioxidant capacity and prevented cardiac oxidative stress: it enhanced the reduction of reactive oxygen species generation, exerted a significant decrease in lipid peroxidation and enhanced glutathione contents in heart tissues compared to the control, Zn, and olmesartan treatments. Our results demonstrate that continuous oral administration of ZnOlme causes a better antihypertensive effect and grants enhancement of cardioprotection through antioxidant activity, in combination with hemodynamic improvement.

Eosinophils protect pressure overload- and β-adrenoreceptor agonist-induced cardiac hypertrophy

AIMS

Blood eosinophil (EOS) counts and EOS cationic protein (ECP) levels associate positively with major cardiovascular disease (CVD) risk factors and prevalence. This study investigates the role of EOS in cardiac hypertrophy.

METHODS AND RESULTS

A retrospective cross-section study of 644 consecutive inpatients with hypertension examined the association between blood EOS counts and cardiac hypertrophy. Pressure overload- and β-adrenoreceptor agonist isoproterenol-induced cardiac hypertrophy was produced in EOS-deficient ΔdblGATA mice. This study revealed positive correlations between blood EOS counts and left ventricular (LV) mass and mass index in humans. ΔdblGATA mice showed exacerbated cardiac hypertrophy and dysfunction, with increased LV wall thickness, reduced LV internal diameter, and increased myocardial cell size, death, and fibrosis. Repopulation of EOS from wild-type (WT) mice, but not those from IL4-deficient mice ameliorated cardiac hypertrophy and cardiac dysfunctions. In ΔdblGATA and WT mice, administration of ECP mEar1 improved cardiac hypertrophy and function. Mechanistic studies demonstrated that EOS expression of IL4, IL13, and mEar1 was essential to control mouse cardiomyocyte hypertrophy and death and cardiac fibroblast TGF-β signalling and fibrotic protein synthesis. The use of human cardiac cells yielded the same results. Human ECP, EOS-derived neurotoxin, human EOS, or murine recombinant mEar1 reduced human cardiomyocyte death and hypertrophy and human cardiac fibroblast TGF-β signalling.

CONCLUSION

Although blood EOS counts correlated positively with LV mass or LV mass index in humans, this study established a cardioprotective role for EOS IL4 and cationic proteins in cardiac hypertrophy and tested a therapeutic possibility of ECPs in this human CVD.

mTOR inhibitor improves testosterone-induced myocardial hypertrophy in hypertensive rats

Compelling evidence has described that the incidence of hypertension and left ventricular hypertrophy (LVH) in postmenopausal women is significantly increased worldwide. Our team's previous research identified that androgen was an underlying factor contributing to increased blood pressure and LVH in postmenopausal women. However, little is known about how androgens affect LVH in postmenopausal hypertensive women. The purpose of this study was to evaluate the role of mammalian rapamycin receptor (mTOR) signaling pathway in myocardial hypertrophy in androgen-induced postmenopausal hypertension and whether mTOR inhibitors can protect the myocardium from androgen-induced interference to prevent and treat cardiac hypertrophy. For that, ovariectomized (OVX) spontaneously hypertensive rats (SHR) aged 12 weeks were used to study the effects of testosterone (T 2.85 mg/kg/weekly i.m.) on blood pressure and myocardial tissue. On the basis of antihypertensive therapy (chlorthalidone 8 mg/kg/day ig), the improvement of blood pressure and myocardial hypertrophy in rats treated with different dose gradients of rapamycin (0.8 mg/kg/day vs 1.5 mg/kg/day vs 2 mg/kg/day i.p.) in OVX + estrogen (E 9.6 mg/kg/day, ig) + testosterone group was further evaluated. After testosterone intervention, the OVX female rats exhibited significant increments in the heart weight/tibial length (TL), area of cardiomyocytes and the mRNA expressions of ANP, β-myosin heavy chain and matrix metalloproteinase 9 accompanied by a significant reduction in the uterine weight/TL and tissue inhibitor of metalloproteinase 1. mTOR, ribosomal protein S6 kinase (S6K1), 4E-binding protein 1 (4EBP1) and eukaryotic translation initiation factor 4E in myocardial tissue of OVX + estrogen + testosterone group were expressed at higher levels than those of the other four groups. On the other hand, rapamycin abolished the effects of testosterone-induced cardiac hypertrophy, decreased the systolic and diastolic blood pressure of SHR, and inhibited the activation of mTOR/S6K1/4EBP1 signaling pathway in a concentration-dependent manner. Collectively, these data suggest that the mTOR/S6K1/4EBP1 pathway is an important therapeutic target for the prevention of LVH in postmenopausal hypertensive female rats with high testosterone levels. Our findings also support the standpoint that the mTOR inhibitor, rapamycin, can eliminate testosterone-induced cardiomyocyte hypertrophy.

A Discrepancy: Calcium Channel Blockers Are Effective for the Treatment of Hypertensive Left Ventricular Hypertrophy but Not as Effective for Prevention of Heart Failure

Arterial hypertension (HTN) is important due to its high prevalence, morbidity, and mortality rates. Calcium channel blockers (CCBs) are the first-line antihypertensive drugs. HTN can lead to heart failure (HF) by causing hypertensive left ventricular hypertrophy (HTN LVH). CCBs are recommended for the treatment of HTN LVH. The aim of this study was to analyze the status of CCBs regarding (1) HTN LVH treatment and (2) capability to prevent HTN-induced HF in the guidelines. For this narrative review, the following databases were searched: Medline, Scopus, Science Direct, Springer, SAGE, Wiley, Oxford Journals, Cambridge, and Google Scholar. CCBs are effective antihypertensive drugs and a very good therapeutic option for HTN LVH as they can cause reverse LVH remodeling. Consequently, we may expect that CCBs would prevent HF. However, evidence suggests that CCBs confer less protection from HF than other first-line antihypertensive drugs. A negative inotropic action of nondihydropyridine CCBs may contribute to suboptimal protection against HF. This discrepancy is clinically relevant because CCBs are in one of the two recommended (single pill) combinations for the initial treatment of HTN. LVH is a strong risk factor for HF in HTN patients. When LVH arises, the risk of HF increases dramatically. CCBs are inferior to renin-angiotensin-aldosterone system blockers but still very effective in bringing about regression of HTN LVH; consequently, CCBs are expected to protect from HF. On the contrary, CCBs protect from HF less effectively than other first-line antihypertensive drugs. This discrepancy needs to be investigated further to improve clinical practice.

Antagonizing the CX3CR1 Receptor Markedly Reduces Development of Cardiac Hypertrophy After Transverse Aortic Constriction in Mice

ABSTRACT

Left-ventricular hypertrophy, characterized by cardiomyocyte hypertrophy, interstitial cell proliferation, and immune cell infiltration, is a high risk factor for heart failure and death. Chemokines interacting with G protein-coupled chemokine receptors probably play a role in left-ventricular hypertrophy development by promoting recruitment of activated leukocytes and modulating left-ventricular remodeling. Using the minimally invasive model of transverse aortic constriction in mice, we demonstrated that a variety of chemokine and chemokine receptor messenger Ribonucleic Acid are overexpressed in the early and late phase of hypertrophy progression. Among the chemokine receptors, Cx3cr1 and Ccr2 were most strongly overexpressed and were significantly upregulated at 3, 7, and 14 days after transverse aortic constriction. Ligands of CX3CR1 (Cx3cl1) and CCR2 (Ccl2, Ccl7, Ccl12) were significantly overexpressed in the left ventricle at the early stages after mechanical pressure overload. Pharmacological inhibition of CX3CR1 signaling using the antagonist AZD8797 led to a significant reduction of hypertrophy, whereas inhibition of CCR2 with the RS504393 antagonist did not show any effect. Furthermore, AZD8797 treatment reduced the expression of the hypertrophic marker genes Nppa and Nppb as well as the profibrotic genes Tgfb1 and Col1a1 at 14 days after transverse aortic constriction. These findings strongly suggest the involvement of the CX3CR1/CX3CL1 pathway in the pathogenesis of left-ventricular hypertrophy.

Investigation of the Antihypertrophic and Antifibrotic Effects of Losartan in a Rat Model of Radiation-Induced Heart Disease

Radiation-induced heart disease (RIHD) is a potential late side-effect of thoracic radiotherapy resulting in left ventricular hypertrophy (LVH) and fibrosis due to a complex pathomechanism leading to heart failure. Angiotensin-II receptor blockers (ARBs), including losartan, are frequently used to control heart failure of various etiologies. Preclinical evidence is lacking on the anti-remodeling effects of ARBs in RIHD, while the results of clinical studies are controversial. We aimed at investigating the effects of losartan in a rat model of RIHD. Male Sprague-Dawley rats were studied in three groups: (1) control, (2) radiotherapy (RT) only, (3) RT treated with losartan (per os 10 mg/kg/day), and were followed for 1, 3, or 15 weeks. At 15 weeks post-irradiation, losartan alleviated the echocardiographic and histological signs of LVH and fibrosis and reduced the overexpression of chymase, connective tissue growth factor, and transforming growth factor-beta in the myocardium measured by qPCR; likewise, the level of the SMAD2/3 protein determined by Western blot decreased. In both RT groups, the pro-survival phospho-AKT/AKT and the phospho-ERK1,2/ERK1,2 ratios were increased at week 15. The antiremodeling effects of losartan seem to be associated with the repression of chymase and several elements of the TGF-β/SMAD signaling pathway in our RIHD model.

Beneficial effects of sodium glucose cotransporter 2 inhibitors on left ventricular mass in patients with diabetes mellitus

BACKGROUND

Sodium glucose cotransporter 2 inhibitor (SGLT2i) has recently been suggested to reduce the risk of cardiovascular events. Left ventricular hypertrophy (LVH) is associated with cardiovascular events. Diabetic macroangiopathy is a crucial complication in patients with diabetes mellitus (DM). This study examined the effect of SGLT2i on LVH in patients with type 2 DM (T2DM).

METHODS

The retrospective cohort study was conducted in consecutive outpatients with T2DM from 2010 to 2020. Left ventricular mass index (LVMI) was used as an indicator of LVH based on echocardiography. The minimum follow-up period was 1 year. After propensity score-matching for clinical profiles, patients who underwent annual echocardiography twice for a routine checkup and took SGLT2i were defined to the SGLT2i group, whereas patients without SGLT2 inhibitors were defined to the non-SGLT2 group. SGLT2i was administered after baseline echocardiography followed by a second examination.

RESULTS

LVMI levels in the SGLT2i group (n = 169) significantly decreased from baseline compared with those in the non-SGLT2i group (n = 169), % changes in LVMI2.7(g/m^2.7 ) in median (interquartile ranges [IQR]) were - 7.7 (-18.7, 2.5) vs -3.6 (-14.3, 5.8), respectively, P = 0.017). In a subgroup analysis, LVMI levels in the patients who had LVH in the SGLT2i group more significantly decreased than those without LVH, % changes in LVMI2.7(g/m^2.7 ) in median (IQR) were -13.5 (-22.1, -2.4) vs -2.8 (-12.6, 9.8), respectively, P < 0.001).

CONCLUSIONS

SGLT2i treatment was shown to improve LVH in patients with T2DM and may play a pivotal role in the future treatment of diabetic cardiovascular complications.

Leptin Attenuates Cardiac Hypertrophy in Patients With Generalized Lipodystrophy

CONTEXT

Lipodystrophy syndromes are rare disorders of deficient adipose tissue, low leptin, and severe metabolic disease, affecting all adipose depots (generalized lipodystrophy, GLD) or only some (partial lipodystrophy, PLD). Left ventricular (LV) hypertrophy is common (especially in GLD); mechanisms may include hyperglycemia, dyslipidemia, or hyperinsulinemia.

OBJECTIVE

Determine effects of recombinant leptin (metreleptin) on cardiac structure and function in lipodystrophy.

METHODS

Open-label treatment study of 38 subjects (18 GLD, 20 PLD) at the National Institutes of Health before and after 1 (N = 27), and 3 to 5 years (N = 23) of metreleptin. Outcomes were echocardiograms, blood pressure (BP), triglycerides, A1c, and homeostasis model assessment of insulin resistance.

RESULTS

In GLD, metreleptin lowered triglycerides (median [interquartile range] 740 [403-1239], 138 [88-196], 211 [136-558] mg/dL at baseline, 1 year, 3-5 years, P < .0001), A1c (9.5 ± 3.0, 6.5 ± 1.6, 6.5 ± 1.9%, P < .001), and HOMA-IR (34.1 [15.2-43.5], 8.7 [2.4-16.0], 8.9 [2.1-16.4], P < .001). Only HOMA-IR improved in PLD (P < .01). Systolic BP decreased in GLD but not PLD. Metreleptin improved cardiac parameters in patients with GLD, including reduced posterior wall thickness (9.8 ± 1.7, 9.1 ± 1.3, 8.3 ± 1.7 mm, P < .01), and LV mass (140.7 ± 45.9, 128.7 ± 37.9, 110.9 ± 29.1 g, P < .01), and increased septal e' velocity (8.6 ± 1.7, 10.0 ± 2.1, 10.7 ± 2.4 cm/s, P < .01). Changes remained significant after adjustment for BP. In GLD, multivariate models suggested that reduced posterior wall thickness and LV mass index correlated with reduced triglycerides and increased septal e' velocity correlated with reduced A1c. No changes in echocardiographic parameters were seen in PLD.

CONCLUSION

Metreleptin attenuated cardiac hypertrophy and improved septal e' velocity in GLD, which may be mediated by reduced lipotoxicity and glucose toxicity. The applicability of these findings to leptin-sufficient populations remains to be determined.

Randomized controlled trial of perhexiline on regression of left ventricular hypertrophy in patients with symptomatic hypertrophic cardiomyopathy (RESOLVE-HCM trial)

BACKGROUND

The presence and extent of left ventricular hypertrophy (LVH) is a major determinant of symptoms in patients with hypertrophic cardiomyopathy (HCM). There is increasing evidence to suggest that myocardial energetic impairment represents a central mechanism leading to LVH in HCM. There is currently a significant unmet need for disease-modifying therapy that regresses LVH in HCM patients. Perhexiline, a potent carnitine palmitoyl transferase-1 (CPT-1) inhibitor, improves myocardial energetics in HCM, and has the potential to reduce LVH in HCM.

OBJECTIVE

The primary objective is to evaluate the effects of perhexiline treatment on the extent of LVH, in symptomatic HCM patients with at least moderate LVH.

METHODS/DESIGN

RESOLVE-HCM is a prospective, multicenter double-blind placebo-controlled randomized trial enrolling symptomatic HCM patients with at least moderate LVH. Sixty patients will be randomized to receive either perhexiline or matching placebo. The primary endpoint is change in LVH, assessed utilizing cardiovascular magnetic resonance (CMR) imaging, after 12-months treatment with perhexiline.

SUMMARY

RESOLVE-HCM will provide novel information on the utility of perhexiline in regression of LVH in symptomatic HCM patients. A positive result would lead to the design of a Phase 3 clinical trial addressing long-term effects of perhexiline on risk of heart failure and mortality in HCM patients.

Dietary carbohydrates restriction inhibits the development of cardiac hypertrophy and heart failure

AIMS

A diet with modified components, such as a ketogenic low-carbohydrate (LC) diet, potentially extends longevity and healthspan. However, how an LC diet impacts on cardiac pathology during haemodynamic stress remains elusive. This study evaluated the effects of an LC diet high in either fat (Fat-LC) or protein (Pro-LC) in a mouse model of chronic hypertensive cardiac remodelling.

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, haemodynamic, 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 signalling.

CONCLUSION

Strict carbohydrate restriction suppresses pathological cardiac growth and heart failure after pressure overload through distinct anti-hypertrophic mechanisms elicited by supplemented macronutrients.

Acylated Ghrelin Attenuates l-Thyroxin-induced Cardiac Damage in Rats by Antioxidant and Anti-inflammatory Effects and Downregulating Components of the Cardiac Renin-angiotensin System

ABSTRACT

This study investigated the protective effect of acylated ghrelin (AG) against l-thyroxin (l-Thy)-induced cardiac damage in rats and examined possible mechanisms. Male rats were divided into five intervention groups of 12 rats/group: control, control + AG, l-Thy, l-Thy + AG, and l-Thy + AG + [D-Lys3]-GHRP-6 (AG antagonist). l-Thy significantly reduced the levels of AG and des-acyl ghrelin and the AG to des-acyl ghrelin ratio. Administration of AG to l-Thy-treated rats reduced cardiac weights and levels of reactive oxygen species and preserved the function and structure of the left ventricle. In addition, AG also reduced the protein levels of cleaved caspase-3 and cytochrome c and prevented mitochondrial permeability transition pore opening. In the left ventricle of both control + AG-treated and l-Thy + AG-treated rats, AG significantly increased left ventricular levels of manganese superoxide dismutase (SOD2), total glutathione (GSH), and Bcl2. It also reduced the levels of malondialdehyde, tumor necrosis factor-α (TNF-α), interleukin-6, and Bax and the nuclear activity of nuclear factor-kappa B. Concomitantly, in both treated groups, AG reduced the mRNA and protein levels of NADPH oxidase 1, angiotensin (Ang) II type 1 receptor, and Ang-converting enzyme 2. All the beneficial effects of AG in l-Thy-treated rats were prevented by the coadministration of [D-Lys3]-GHRP-6, a selective growth hormone secretagogue receptor subtype 1a antagonist. In conclusion, AG protects against hyperthyroidism-induced cardiac hypertrophy and damage, which is mainly due to its antioxidant and anti-inflammatory potentials and requires the activation of GHS-R1a.

Endostatin attenuates heart failure via inhibiting reactive oxygen species in myocardial infarction rats

The purpose of the present study was to evaluate whether endostatin overexpression could improve cardiac function, hemodynamics, and fibrosis in heart failure (HF) via inhibiting reactive oxygen species (ROS). The HF models were established by inducing ischemia myocardial infarction (MI) through ligation of the left anterior descending (LAD) artery in Sprague-Dawley (SD) rats. Endostatin level in serum was increased in MI rats. The decrease in cardiac function and hemodynamics in MI rats were enhanced by endostatin overexpression. Endostatin overexpression inhibited the increase in collagen I, collagen III, α-smooth muscle actin (α-SMA), connective tissue growth factor (CTGF), matrix metalloproteinase (MMP)-2 and MMP9 in the hearts of MI rats. MI-induced cardiac hypertrophy was reduced by endostatin overexpression. The increased levels of malondialdehyde (MDA), superoxide anions, the promoted NAD(P)H oxidase (Nox) activity, and the reduced superoxide dismutase (SOD) activity in MI rats were reversed by endostatin overexpression. Nox4 overexpression inhibited the cardiac protective effects of endostatin. These results demonstrated that endostatin improved cardiac dysfunction and hemodynamics, and attenuated cardiac fibrosis and hypertrophy via inhibiting oxidative stress in MI-induced HF rats.

Change in waist circumference over 2 years and the odds of left ventricular hypertrophy among Chinese children

BACKGROUND AND AIMS

High waist circumference (WC) is associated with left ventricular mass index (LVMI) in childhood. However, no studies have assessed the association between WC change and left ventricular hypertrophy (LVH) in childhood. This study aimed to investigate the association between change in WC status over 2 years on LVH among Chinese children.

METHODS AND RESULTS

Data were from a population-based prospective cohort study in China. Children without LVH at baseline (n = 1067) were assigned to four WC status change groups (persistent normal WC, WC loss, WC gain, and persistent abdominal obesity). Over a 2-year follow-up, 103 (out of 1067) children had LVH. LVMI levels were the highest among the persistent abdominal obesity group (31.5 ± 3.8 g/m ^2.7), lower in the WC gain group (31.0 ± 3.6 g/m ^2.7) and the WC loss group (29.8 ± 3.7 g/m ^2.7), and lowest in the persistent normal WC group (29.1 ± 3.7 g/m ^2.7). Compared with children in the persistent normal WC group, the odds of LVH was highest in the persistent abdominal obesity group [odds ratio (OR) = 3.57, 95% confidence interval (CI): 2.18-5.83], followed by the WC gain group (OR = 2.85, 95% CI: 1.50-5.41). In contrast, the odds of LVH was not increased in the WC loss group (OR = 0.93, 95% CI: 0.21-4.07).

CONCLUSION

Although these findings highlight the importance of maintaining normal WC in childhood to reduce the odds of developing LVH, our data suggest the increased odds associated with abdominal obesity can be reversed by WC loss.

Effects of Sodium-Glucose Linked Transporter 2 Inhibition With Ertugliflozin on Mitochondrial Function, Energetics, and Metabolic Gene Expression in the Presence and Absence of Diabetes Mellitus in Mice

Background Inhibitors of the sodium-glucose linked transporter 2 improve cardiovascular outcomes in patients with or without type 2 diabetes mellitus, but the effects on cardiac energetics and mitochondrial function are unknown. We assessed the effects of sodium-glucose linked transporter 2 inhibition on mitochondrial function, high-energy phosphates, and genes encoding mitochondrial proteins in hearts of mice with and without diet-induced diabetic cardiomyopathy. Methods and Results Mice fed a control diet or a high-fat, high-sucrose diet received ertugliflozin mixed with the diet (0.5 mg/g of diet) for 4 months. Isolated mitochondria were assessed for functional capacity. High-energy phosphates were assessed by 31P nuclear magnetic resonance spectroscopy concurrently with contractile performance in isolated beating hearts. The high-fat, high-sucrose diet caused myocardial hypertrophy, diastolic dysfunction, mitochondrial dysfunction, and impaired energetic response, all of which were prevented by ertugliflozin. With both diets, ertugliflozin caused supernormalization of contractile reserve, as measured by rate×pressure product at high work demand. Likewise, the myocardial gene sets most enriched by ertugliflozin were for oxidative phosphorylation and fatty acid metabolism, both of which were enriched independent of diet. Conclusions Ertugliflozin not only prevented high-fat, high-sucrose-induced pathological cardiac remodeling, but improved contractile reserve and induced the expression of oxidative phosphorylation and fatty acid metabolism gene sets independent of diabetic status. These effects of sodium-glucose linked transporter 2 inhibition on cardiac energetics and metabolism may contribute to improved structure and function in cardiac diseases associated with mitochondrial dysfunction, such as heart failure.

Dapagliflozin: a sodium-glucose cotransporter 2 inhibitor, attenuates angiotensin II-induced cardiac fibrotic remodeling by regulating TGFβ1/Smad signaling

BACKGROUND

Cardiac remodeling is one of the major risk factors for heart failure. In patients with type 2 diabetes, sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce the risk of the first hospitalization for heart failure, possibly through glucose-independent mechanisms in part, but the underlying mechanisms remain largely unknown. This study aimed to shed light on the efficacy of dapagliflozin in reducing cardiac remodeling and potential mechanisms.

METHODS

Sprague-Dawley (SD) rats, induced by chronic infusion of Angiotensin II (Ang II) at a dose of 520 ng/kg per minute for 4 weeks with ALZET® mini-osmotic pumps, were treated with either SGLT2 inhibitor dapagliflozin (DAPA) or vehicle alone. Echocardiography was performed to determine cardiac structure and function. Cardiac fibroblasts (CFs) were treated with Ang II (1 μM) with or without the indicated concentration (0.5, 1, 10 μM) of DAPA. The protein levels of collagen and TGF-β1/Smad signaling were measured along with body weight, and blood biochemical indexes.

RESULTS

DAPA pretreatment resulted in the amelioration of left ventricular dysfunction in Ang II-infused SD rats without affecting blood glucose and blood pressure. Myocardial hypertrophy, fibrosis and increased collagen synthesis caused by Ang II infusion were significantly inhibited by DAPA pretreatment. In vitro, DAPA inhibit the Ang II-induced collagen production of CFs. Immunoblot with heart tissue homogenates from chronic Ang II-infused rats revealed that DAPA inhibited the activation of TGF-β1/Smads signaling.

CONCLUSION

DAPA ameliorates Ang II-induced cardiac remodeling by regulating the TGF-β1/Smad signaling in a non-glucose-lowering dependent manner.

Assessment of Carotid Intima Media Thickness and Left Ventricular Mass Index in Children with Idiopathic Nephrotic Syndrome

BACKGROUND

Children with nephrotic syndrome (NS) are at a greater risk of atherosclerosis due to recurrent exposures to hyperlipidemia, hypertension, and immunosuppressive medications. CIMT (carotid intima media thickness) is a reliable marker for assessment of atherosclerosis of large and medium-sized blood vessels; endothelial dysfunction and increased CIMT usually precede the development of cardiovascular diseases. Some manifestations of NS, like proteinuria and hyperlipidemia, are associated with an increased risk of cardiac morbidity and mortality. The aim of the current study was to evaluate the carotid intima media thickness and LVM (left ventricular mass) thickness in children with nephrotic syndrome.

SUBJECTS AND METHODS

Eighty-one children with nephrotic syndrome and 100 healthy children as controls were enrolled in the study. The inclusion criteria were: disease duration of minimum of 12 months, glomerular filtration rate >60mL/min/1.73m 2 and children aged two years or more at the time of study. CIMT and left ventricular mass index, lipid profile, protein/creatinine ratio in urine and kidney function tests were done for cases and controls after approval of internal ethical committee.

RESULTS

The mean CIMT (mm) was significantly higher in NS (0.51± 0.12) compared to controls (0.42± 0.09) (P <0.001). LVM and LVM Index were significantly higher in NS than controls (p< 0.001, for both). Subsequently, CIMT was significantly correlated to duration of the disease (p< 0.001), LVM index was significantly correlated with duration of the disease, body mass index (BMI), blood pressures and triglycerides level (p< 0.05).

CONCLUSION

Children with NS are at increasing risk to develop atherosclerosis as measured by CIMT. LVM was significantly higher in NS and positively correlated to BP, disease duration, triglyceride levels and BMI.

AAV-mediated expression of NFAT decoy oligonucleotides protects from cardiac hypertrophy and heart failure

Previous studies have underlined the substantial role of nuclear factor of activated T cells (NFAT) in hypertension-induced myocardial hypertrophy ultimately leading to heart failure. Here, we aimed at neutralizing four members of the NFAT family of transcription factors as a therapeutic strategy for myocardial hypertrophy transiting to heart failure through AAV-mediated cardiac expression of a RNA-based decoy oligonucleotide (dON) targeting NFATc1-c4. AAV-mediated dON expression markedly decreased endothelin-1 induced cardiomyocyte hypertrophy in vitro and resulted in efficient expression of these dONs in the heart of adult mice as evidenced by fluorescent in situ hybridization. Cardiomyocyte-specific dON expression both before and after induction of transverse aortic constriction protected mice from development of cardiac hypertrophy, cardiac remodeling, and heart failure. Singular systemic administration of AAVs enabling a cell-specific expression of dONs for selective neutralization of a given transcription factor may thus represent a novel and powerful therapeutic approach.

Increased cholinergic activity under conditions of low estrogen leads to adverse cardiac remodeling

Cholinesterase inhibitors are used in postmenopausal women for the treatment of neurodegenerative diseases. Despite their widespread use in the clinical practice, little is known about the impact of augmented cholinergic signaling on cardiac function under reduced estrogen conditions. To address this gap, we subjected a genetically engineered murine model of systemic vesicular acetylcholine transporter overexpression (Chat-ChR2) to ovariectomy and evaluated cardiac parameters. Left-ventricular function was similar between Chat-ChR2 and wild-type (WT) mice. Following ovariectomy, WT mice showed signs of cardiac hypertrophy. Conversely, ovariectomized (OVX) Chat-ChR2 mice evolved to cardiac dilation and failure. Transcript levels for cardiac stress markers atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) were similarly upregulated in WT/OVX and Chat-ChR2/OVX mice. 17β-Estradiol (E2) treatment normalized cardiac parameters in Chat-ChR2/OVX to the Chat-ChR2/SHAM levels, providing a link between E2 status and the aggravated cardiac response in this model. To investigate the cellular basis underlying the cardiac alterations, ventricular myocytes were isolated and their cellular area and contractility were assessed. Myocytes from WT/OVX mice were wider than WT/SHAM, an indicative of concentric hypertrophy, but their fractional shortening was similar. Conversely, Chat-ChR2/OVX myocytes were elongated and presented contractile dysfunction. E2 treatment again prevented the structural and functional changes in Chat-ChR2/OVX myocytes. We conclude that hypercholinergic mice under reduced estrogen conditions do not develop concentric hypertrophy, a critical compensatory adaptation, evolving toward cardiac dilation and failure. This study emphasizes the importance of understanding the consequences of cholinesterase inhibition, used clinically to treat dementia, for cardiac function in postmenopausal women.

Nutraceutical, Dietary, and Lifestyle Options for Prevention and Treatment of Ventricular Hypertrophy and Heart Failure

Although well documented drug therapies are available for the management of ventricular hypertrophy (VH) and heart failure (HF), most patients nonetheless experience a downhill course, and further therapeutic measures are needed. Nutraceutical, dietary, and lifestyle measures may have particular merit in this regard, as they are currently available, relatively safe and inexpensive, and can lend themselves to primary prevention as well. A consideration of the pathogenic mechanisms underlying the VH/HF syndrome suggests that measures which control oxidative and endoplasmic reticulum (ER) stress, that support effective nitric oxide and hydrogen sulfide bioactivity, that prevent a reduction in cardiomyocyte pH, and that boost the production of protective hormones, such as fibroblast growth factor 21 (FGF21), while suppressing fibroblast growth factor 23 (FGF23) and marinobufagenin, may have utility for preventing and controlling this syndrome. Agents considered in this essay include phycocyanobilin, N-acetylcysteine, lipoic acid, ferulic acid, zinc, selenium, ubiquinol, astaxanthin, melatonin, tauroursodeoxycholic acid, berberine, citrulline, high-dose folate, cocoa flavanols, hawthorn extract, dietary nitrate, high-dose biotin, soy isoflavones, taurine, carnitine, magnesium orotate, EPA-rich fish oil, glycine, and copper. The potential advantages of whole-food plant-based diets, moderation in salt intake, avoidance of phosphate additives, and regular exercise training and sauna sessions are also discussed. There should be considerable scope for the development of functional foods and supplements which make it more convenient and affordable for patients to consume complementary combinations of the agents discussed here. Research Strategy: Key word searching of PubMed was employed to locate the research papers whose findings are cited in this essay.

Disruption of actin dynamics regulated by Rho effector mDia1 attenuates pressure overload-induced cardiac hypertrophic responses and exacerbates dysfunction

AIMS

Cardiac hypertrophy is a compensatory response to pressure overload, leading to heart failure. Recent studies have demonstrated that Rho is immediately activated in left ventricles after pressure overload and that Rho signalling plays crucial regulatory roles in actin cytoskeleton rearrangement during cardiac hypertrophic responses. However, the mechanisms by which Rho and its downstream proteins control actin dynamics during hypertrophic responses remain not fully understood. In this study, we identified the pivotal roles of mammalian homologue of Drosophila diaphanous (mDia) 1, a Rho-effector molecule, in pressure overload-induced ventricular hypertrophy.

METHODS AND RESULTS

Male wild-type (WT) and mDia1-knockout (mDia1KO) mice (10-12 weeks old) were subjected to a transverse aortic constriction (TAC) or sham operation. The heart weight/tibia length ratio, cardiomyocyte cross-sectional area, left ventricular wall thickness, and expression of hypertrophy-specific genes were significantly decreased in mDia1KO mice 3 weeks after TAC, and the mortality rate was higher at 12 weeks. Echocardiography indicated that mDia1 deletion increased the severity of heart failure 8 weeks after TAC. Importantly, we could not observe apparent defects in cardiac hypertrophic responses in mDia3-knockout mice. Microarray analysis revealed that mDia1 was involved in the induction of hypertrophy-related genes, including immediate early genes, in pressure overloaded hearts. Loss of mDia1 attenuated activation of the mechanotransduction pathway in TAC-operated mice hearts. We also found that mDia1 was involved in stretch-induced activation of the mechanotransduction pathway and gene expression of c-fos in neonatal rat ventricular cardiomyocytes (NRVMs). mDia1 regulated the filamentous/globular (F/G)-actin ratio in response to pressure overload in mice. Additionally, increases in nuclear myocardin-related transcription factors and serum response factor were perturbed in response to pressure overload in mDia1KO mice and to mechanical stretch in mDia1 depleted NRVMs.

CONCLUSION

mDia1, through actin dynamics, is involved in compensatory cardiac hypertrophy in response to pressure overload.

Effects of Caloric Restriction Diet on Arterial Hypertension and Endothelial Dysfunction

The most common manifestation of cardiovascular (CV) diseases is the presence of arterial hypertension (AH), which impacts on endothelial dysfunction. CV risk is associated with high values of systolic and diastolic blood pressure and depends on the presence of risk factors, both modifiable and not modifiable, such as overweight, obesity, physical exercise, smoking, age, family history, and gender. The main target organs affected by AH are the heart, brain, vessels, kidneys, and eye retina. AH onset can be counteracted or delayed by adopting a proper diet, characterized by a low saturated fat and sodium intake, a high fruit and vegetable intake, a moderate alcohol consumption, and achieving and maintaining over time the ideal body weight. In this review, we analyzed how a new nutritional approach, named caloric restriction diet (CRD), can provide a significant reduction in blood pressure values and an improvement of the endothelial dysfunction. In fact, CRD is able to counteract aging and delay the onset of CV and neurodegenerative diseases through the reduction of body fat mass, systolic and diastolic values, free radicals production, and oxidative stress. Currently, there are few studies on CRD effects in the long term, and it would be advisable to perform observational studies with longer follow-up.

Xanthohumol attenuates isoprenaline-induced cardiac hypertrophy and fibrosis through regulating PTEN/AKT/mTOR pathway

Emerging evidence suggests the cardiovascular protective effects of Xanthohumol (Xn), a prenylated flavonoid isolated from the hops (Humulus lupulus L.). However, the cardioprotective effect of Xn remains unclear. Present study aimed to investigate the protective role of Xn against isoprenaline (ISO)-induced cardiac hypertrophy and fibrosis, and elucidate the underlying mechanism. The cardiac hypertrophy and fibrosis model were established via subcutaneously administration of ISO. ISO reduced the left ventricular contractile function and elevated myocardial enzyme levels, suggesting cardiac dysfunction. Moreover, the increased cardiac myocyte area, heart weight/body weight (HW/BW) ratio and ANP/BNP expressions indicated the ISO-induced hypertrophy, while the excessive collagen-deposition and up-regulation of fibrosis marker protein (α-SMA, Collagen-I/III) expression indicated the ISO-induced fibrosis. The ISO-induced cardiac dysfunction, hypertrophy and fibrosis were significantly attenuated by oral administrated with Xn. PTEN/AKT/mTOR pathway has been reported to involve in pathogenesis of cardiac hypertrophy and fibrosis. We found that Xn administration up-regulated PTEN expression and inhibited the phosphorylation of AKT/mTOR in ISO-treated mice. Moreover, treating with VO-ohpic, a specific PTEN inhibitor, abolished the cardioprotective effect of Xn. Collectively, these results suggested that Xn attenuated ISO-induced cardiac hypertrophy and fibrosis through regulating PTEN/AKT/mTOR pathway.

The association between left ventricular hypertrophy and consumption of nuts, including peanuts, pine nuts, and almonds

BACKGROUND AND AIMS

Studies have reported that nut consumption is potentially beneficial in preventing cardiovascular disease. However, data are insufficient regarding the association between nut consumption and left ventricular hypertrophy (LVH).

METHODS AND RESULTS

In the Kangbuk Samsung Health Study, the participants were 34,617 men and 12,257 women who completed a food-frequency questionnaire for nut consumption and received echocardiography. Nut consumption was evaluated only for peanuts, pine nuts, and almonds defining 15 g as one serving/servings dose. Multivariable adjusted odds ratio (OR) and 95% confidence interval (CI) for LVH were evaluated according to the consumption frequency of one serving dose of nut. The frequency of nut consumption was categorized into five groups (<1/month, 1/month-1/week, 1-2/week, 2-4/week, and ≥4/week). The subgroup analysis was conducted by dividing the participants into the following two groups: the nonhypertensive/nondiabetic group and hypertensive or diabetic group. In women, nut consumption ≥2/week had the lower multivariable adjusted OR and 95% CI for LVH (2-4/week: 0.46 [0.26-0.81] and ≥4/week: 0.48 [0.25-0.92]) when compared with nut consumption <1/month. This association was identically observed in the subgroup analysis for women without hypertension and diabetes mellitus (DM) and women with hypertension or DM. However, men did not show the significant association.

CONCLUSION

In women, nut consumption ≥2/week was associated with the decreased probability of LVH. Further research studies should investigate whether the beneficial effect of nut consumption on LV structure results in better cardiovascular prognosis.

Alamandine improves cardiac remodeling induced by transverse aortic constriction in mice

Alamandine is the newest identified peptide of the renin-angiotensin system (RAS) and has protective effects in the cardiovascular system. Although the involvement of classical RAS components in the genesis and progression of cardiac remodeling is well known, less is known about the effects of alamandine. Therefore, in the present study we investigated the effects of alamandine on cardiac remodeling induced by transverse aortic constriction (TAC) in mice. Male mice (C57BL/6), 10-12 wk of age, were divided into three groups: sham operated, TAC, and TAC + ALA (30 µg/kg/day alamandine for 14 days). The TAC surgery was performed under ketamine and xylazine anesthesia. At the end of treatment, the animals were submitted to echocardiographic examination and subsequently euthanized for tissue collection. TAC induced myocyte hypertrophy, collagen deposition, and the expression of matrix metalloproteinase (MMP)-2 and transforming growth factor (TGF)-β in the left ventricle. These markers of cardiac remodeling were reduced by oral treatment with alamandine. Western blotting analysis showed that alamandine prevents the increase in ERK1/2 phosphorylation and reverts the decrease in 5'-adenosine monophosphate-activated protein kinase (AMPK)α phosphorylation induced by TAC. Although both TAC and TAC + ALA increased SERCA2 expression, the phosphorylation of phospholamban in the Thr17 residue was increased solely in the alamandine-treated group. The echocardiographic data showed that there are no functional or morphological alterations after 2 wk of TAC. Alamandine treatment prevents myocyte hypertrophy and cardiac fibrosis induced by TAC. Our results reinforce the cardioprotective role of alamandine and highlight its therapeutic potential for treating heart diseases related to pressure overload conditions.NEW & NOTEWORTHY Alamandine is the newest identified component of the renin-angiotensin system protective arm. Considering the beneficial effects already described so far, alamandine is a promising target for cardiovascular disease treatment. We demonstrated for the first time that alamandine improves many aspects of cardiac remodeling induced by pressure overload, including cell hypertrophy, fibrosis, and oxidative stress markers.

N-acetylcysteine protects neonatal mice from ventricular hypertrophy induced by maternal obesity in a sex-specific manner

BACKGROUND

Maternal obesity induces adverse cardiac programming in offspring, and effective interventions are needed to prevent cardiovascular ill-health. Herein we hypothesized that exposure to maternal obesogenic diet-induced obesity in mice results in left ventricular remodelling and hypertrophy in early childhood, and that maternal N-acetylcysteine (NAC) treatment alleviates these effects in a sex-dependent manner.

METHODS AND RESULTS

The maternal obesity was induced in mice by the consumption of a Western diet accompanied by a 20 % sucrose solution. To determine the effect of NAC on the cardiac outcomes induced by maternal obesity, obese dams were continuously exposed to the obesogenic diet, with or without the oral NAC treatment during pregnancy. Left ventricular remodelling and hypertrophy occurred as early as 7 days after birth in the male offspring of obese dams (O-OB) compared with controls (O-CO). An over-expression of key genes and markers related to cardiac fibrosis accompanied by more disorganized myofibrils was observed in the hearts of neonatal male O-OB mice. When we next evaluated the level of oxidative stress in the hearts of neonatal mice, the activity of enzymatic antioxidants declined and expression of NOX enzyme complex was up-regulated in O-OB offspring hearts, but was normal in the offspring of NAC treated mice (O-OB/NAC). Maternal obesity also activated cardiac Akt and mammalian target of rapamycin (mTOR) signalling in offspring, and NAC treatment restored offspring cardiac Akt-mTOR signalling to normal irrespective of sex. NAC treatment did not prevent cardiomyocyte hypertrophy but did alleviate increased heart weight, interventricular septal thickness, and collagen content in male O-OB/NAC pups.

CONCLUSIONS

Collectively, our results indicated that NAC blunted cardiac fibrosis and related ventricular hypertrophy of male neonatal offspring in the setting of maternal obesity, potentially acting by reducing oxidative stress. The present study provides a basis for investigating the role of NAC in nutrition-related cardiac programming.

Qingda granule attenuates angiotensin II-induced cardiac hypertrophy and apoptosis and modulates the PI3K/AKT pathway

Qingda granule (QDG), simplified from Qingxuan Jiangya Decoction, is a well-known traditional Chinese medicine formula that has been used for decades to treat hypertension. However, the cardioprotective effects of QDG on Ang II-induced hypertension remain unknown. This study aimed to investigate the effects of QDG on hypertension-induced cardiac hypertrophy and apoptosis, as well as explore its underlying mechanisms. Mice were infused with Ang II (500 ng/kg/min) or saline solution as control, then administered oral QDG (1.145 g/kg/day) or saline for two weeks. QDG treatment attenuated the elevation in blood pressure caused by Ang II, as well as the decreased left ventricle ejection fractions and fractional shortening. Moreover, QDG treatment significantly alleviated the Ang II-induced elevation of the ratio of heart weight to tibia length, as well as cardiac injury, hypertrophy, and apoptosis. In cultured H9C2 cells stimulated with Ang II, QDG partially reversed the increase in cell surface area and number of apoptotic cells, up-regulation of hypertrophy markers ANP and BNP, and activation of caspases-9 and -3. QDG also partially reversed Ang II-induced accumulation of reactive oxygen species (ROS), depolarization of the mitochondrial membrane, release of cytochrome C, up-regulation of Bax, and decrease in levels of p-PI3K, p-AKT, and Bcl-2. These results suggest that QDG can significantly attenuate Ang II-induced hypertension, cardiac hypertrophy and apoptosis, and it may exert these effects in part by suppressing ROS production and activating the PI3K/AKT signaling pathway.

Grape juice attenuates left ventricular hypertrophy in dyslipidemic mice

OBJECTIVE

We evaluated the effects of grape juice (Vitis labrusca L.) on dyslipidemia, resistance to insulin, and left ventricular hypertrophy (LVH) in mice homozygous for the absence of the LDL receptor gene (LDLr -/-) under a hyperlipidemic diet.

METHODOLOGY

We divided 30 male mice (3 months old) into three groups (n = 10); the HL group was fed a high-fat diet, the HLU group received a high-fat diet and 2 g/kg/day of grape juice, and the HLS group was fed a high-fat diet and simvastatin (20 mg/kg/day). We assessed the blood pressure profile of the mice. We also determined the levels of C-reactive protein (CRP) and lipid profile, glycemic and insulinemic profiles, and calculated the HOMA-IR. Cardiomyocyte hypertrophy, interstitial collagen deposit, and the expression of CD40 ligand (CD40L) and metalloproteinases 2 and 9 were assessed immunohistologically.

RESULTS

After 60 days, the mice treated with grape juice showed similar results as those of the group treated with simvastatin. The use of grape fruit attenuated dyslipidemia and insulin resistance and significantly increased the levels of high cholesterol density lipoproteins (HDLc). The antioxidant potential of phenolic compounds associated with the increase in HDLc levels in the mice of the HLU group prevented the development of LVH and arterial hypertension since it inhibited the inflammatory response induced by the CD40 pathway and its ligand CD40L. Consequently, there was a lower expression of MMP-2 and MMP-9 and lower serum levels of CRP.

CONCLUSION

Grape juice has a hypolipidemic and cardiac protective potential, presenting a similar effect as that of simvastatin through a direct antioxidant action of phenolic compounds, or indirectly, via antioxidant action and anti-inflammatory activity of the HDLc. These results suggest that grape juice is a functional food possessing a high potential to prevent cardiovascular diseases.

Inhibition of heat shock protein 70 blocks the development of cardiac hypertrophy by modulating the phosphorylation of histone deacetylase 2

AIMS

Previously, we reported that phosphorylation of histone deacetylase 2 (HDAC2) and the resulting activation causes cardiac hypertrophy. Through further study of the specific binding partners of phosphorylated HDAC2 and their mechanism of regulation, we can better understand how cardiac hypertrophy develops. Thus, in the present study, we aimed to elucidate the function of one such binding partner, heat shock protein 70 (HSP70).

METHODS AND RESULTS

Primary cultures of rat neonatal ventricular cardiomyocytes and H9c2 cardiomyoblasts were used for in vitro cellular experiments. HSP70 knockout (KO) mice and transgenic (Tg) mice that overexpress HSP70 in the heart were used for in vivo analysis. Peptide-precipitation and immunoprecipitation assay revealed that HSP70 preferentially binds to phosphorylated HDAC2 S394. Forced expression of HSP70 increased phosphorylation of HDAC2 S394 and its activation, but not that of S422/424, whereas knocking down of HSP70 reduced it. However, HSP70 failed to phosphorylate HDAC2 in the cell-free condition. Phosphorylation of HDAC2 S394 by casein kinase 2α1 enhanced the binding of HSP70 to HDAC2, whereas dephosphorylation induced by the catalytic subunit of protein phosphatase 2A (PP2CA) had the opposite effect. HSP70 prevented HDAC2 dephosphorylation by reducing the binding of HDAC2 to PP2CA. HSP70 KO mouse hearts failed to phosphorylate S394 HDAC2 in response to isoproterenol infusion, whereas Tg overexpression of HSP70 increased the phosphorylation and activation of HDAC2. 2-Phenylethynesulfonamide (PES), an HSP70 inhibitor, attenuated cardiac hypertrophy induced either by phenylephrine in neonatal ventricular cardiomyocytes or by aortic banding in mice. PES reduced HDAC2 S394 phosphorylation and its activation by interfering with the binding of HSP70 to HDAC2.

CONCLUSION

These results demonstrate that HSP70 specifically binds to S394-phosphorylated HDAC2 and maintains its phosphorylation status, which results in HDAC2 activation and the development of cardiac hypertrophy. Inhibition of HSP70 has possible application as a therapeutic.

Intermedin alleviates pathological cardiac remodeling by upregulating klotho

Cardiac remodeling is accompanied by cardiac hypertrophy, fibrosis, dysfunction, and eventually leading to heart failure. Intermedin (IMD), as a paracrine/autocrine peptide, has a protective effect in cardiovascular diseases. In this study, we elucidated the role and the underlying mechanism of IMD in pathological remodeling. Pathological remodeling mouse models were induced by abdominal aorta constriction for 4 weeks or angiotensin II (Ang II) infusion for 2 weeks in wildtype, IMD-overexpression, IMD-knockout and klotho-knockdown mice. Western blot, real-time PCR, histological staining, echocardiography and hemodynamics were used to detect the role of IMD in cardiac remodeling. Cardiac hypertrophy, fibrosis and dysfunction were significantly aggravated in IMD-knockout mice versus wildtype mice, and the expression of klotho was downregulated. Conversely, cardiac remodeling was alleviated in IMD-overexpression mice, and the expression of klotho was upregulated. Hypertension induced by Ang II infusion rather than abdominal aorta constriction was mitigated by IMD. However, the cardioprotective effect of IMD was blocked in klotho-knockdown mice. Similar results were found in cultured neonatal rat cardiomyocytes, which was pretreated with IMD before Ang II stimulation. Mechanistically, IMD inhibited the phosphorylation of Ca²⁺/calmodulin-dependent protein kinase II (CaMKII) and the activity of calcineurin to protect against cardiac hypertrophy through upregulating klotho in vivo and in vitro. Furthermore, peroxisome proliferator-activated receptor γ (PPARγ) might mediate IMD upregulating klotho. In conclusion, pathological remodeling may be alleviated by endogenous IMD, which inhibits the expression of calcineurin and p-CaMKII by upregulating klotho via the PPARγ pathway. It suggested that IMD might be a therapeutic target for heart disease.

Effect of Low-Sodium versus Conventional Sodium Dialysate on Left Ventricular Mass in Home and Self-Care Satellite Facility Hemodialysis Patients: A Randomized Clinical Trial

BACKGROUND

Fluid overload in patients undergoing hemodialysis contributes to cardiovascular morbidity and mortality. There is a global trend to lower dialysate sodium with the goal of reducing fluid overload.

METHODS

To investigate whether lower dialysate sodium during hemodialysis reduces left ventricular mass, we conducted a randomized trial in which patients received either low-sodium dialysate (135 mM) or conventional dialysate (140 mM) for 12 months. We included participants who were aged >18 years old, had a predialysis serum sodium ≥135 mM, and were receiving hemodialysis at home or a self-care satellite facility. Exclusion criteria included hemodialysis frequency >3.5 times per week and use of sodium profiling or hemodiafiltration. The main outcome was left ventricular mass index by cardiac magnetic resonance imaging.

RESULTS

The 99 participants had a median age of 51 years old; 67 were men, 31 had diabetes mellitus, and 59 had left ventricular hypertrophy. Over 12 months of follow-up, relative to control, a dialysate sodium concentration of 135 mmol/L did not change the left ventricular mass index, despite significant reductions at 6 and 12 months in interdialytic weight gain, in extracellular fluid volume, and in plasma B-type natriuretic peptide concentration (ratio of intervention to control). The intervention increased intradialytic hypotension (odds ratio [OR], 7.5; 95% confidence interval [95% CI], 1.1 to 49.8 at 6 months and OR, 3.6; 95% CI, 0.5 to 28.8 at 12 months). Five participants in the intervention arm could not complete the trial because of hypotension. We found no effect on health-related quality of life measures, perceived thirst or xerostomia, or dietary sodium intake.

CONCLUSIONS

Dialysate sodium of 135 mmol/L did not reduce left ventricular mass relative to control, despite improving fluid status.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

The Australian New Zealand Clinical Trials Registry, ACTRN12611000975998.

Recommendations for exercise and screening for safe athletic participation in hypertensive youth

Physical activity is an important component of ideal cardiovascular health. Current guidelines recommend that youth with hypertension participate in competitive sports once hypertensive target organ effects and risks have been assessed and that children with hypertension receive treatment to lower BP below stage 2 thresholds (e.g., < 140/90 mmHg or < 95th percentile + 12 mmHg) before participating in competitive sports. Despite these recommendations, pediatricians and pediatric subspecialists continue to struggle with how best to counsel their patients regarding appropriate forms of physical activity, the impact of exercise on blood pressure, and how best to screen for cardiovascular conditions that place youth at risk for sudden cardiac death. This review provides a summary of our current knowledge regarding the safety and utility of exercise in the management of high blood pressure in youth. We review determinants of blood pressure during exercise, the impact of blood pressure on cardiovascular health and structure, mechanisms for assessing cardiometabolic fitness (e.g., exercise stress test), contraindications to athletic participation, and how best to plan for athletic participation among hypertensive youth. Greater knowledge in these areas may offer clarity to providers faced with the challenge of prescribing exercise recommendations for hypertensive youth.

Cardioprotective Effect of a Virgin Olive Oil Enriched with Bioactive Compounds in Spontaneously Hypertensive Rats

Olive oil and its derivatives have been described to exert beneficial effects on hypertensive states and cardiovascular disease prevention. We studied the effects of chronic consumption of extra virgin olive oil (EVOO), enriched in bioactive compounds from olive fruit and leaves, on blood pressure, endothelial function, oxidative and inflammatory status, and circulating cholesterol levels, in spontaneously hypertensive rats (SHR). Thirty SHR were randomly assigned to three groups: a control untreated SHR group, an SHR group (1 mL/rat/day) of a control olive oil (17.6 mg/kg of phenolic compounds), and an SHR group (1 mL/rat/day) of the enriched EVOO (750 mg/kg of phenolic compounds) for eight weeks. Ten Wistar Kyoto rats (WKY) were included as healthy controls. Long-term administration of the enriched EVOO decreased systolic blood pressure and cardiac hypertrophy, and improved the ex vivo aortic endothelial dysfunction measured in SHR. Moreover, enriched oil supplementation reduced the plasma levels of Angiotensin II and total cholesterol, and the urinary levels of endothelin-1 and oxidative stress biomarkers, while pro-inflammatory cytokines were unaffected. In conclusion, sustained treatment with EVOO, enriched in bioactive compounds from the olive fruit and leaves, may be an effective tool for reducing blood pressure and cholesterol levels alone or in combination with pharmacological anti-hypertensive treatment.

Effect of ipragliflozin, an SGLT2 inhibitor, on cardiac histopathological changes in a non-diabetic rat model of cardiomyopathy

AIMS

We investigated the effect of the selective sodium-dependent glucose cotransporter 2 (SGLT2) inhibitor ipragliflozin on cardiac dysfunction and histopathology in a non-diabetic rat model of cardiomyopathy.

MAIN METHODS

Ipragliflozin was mixed with chow (0.01%, w/w) and administered to male DahlS.Z-Lepr^fa/Lepr^fa (DS/obese) rats for 8 weeks. Male DahlS.Z-Lepr⁺/Lepr⁺ (DS/lean) rats of the same age were used as controls. Systolic blood pressure (SBP) and heart rate (HR) were measured every 4 weeks. After 8 weeks of treatment, echocardiography and histopathological examinations were performed. Further, the effect of ipragliflozin on blood and urine parameters were investigated.

KEY FINDINGS

In the DS/obese rats, ipragliflozin delayed the age-related increase in SBP without affecting HR, reduced left ventricular (LV) mass and intraventricular septal thickness in echocardiography, and ameliorated hypertrophy of cardiomyocytes and LV fibrosis in histopathological examination. Although ipragliflozin significantly increased both urine volume and urinary glucose excretion in DS/obese rats, it did not alter plasma glucose levels.

SIGNIFICANCE

Ipragliflozin prevented LV hypertrophy and fibrosis in non-diabetic DS/obese rats without affecting plasma glucose levels. These findings suggest that SGLT2 inhibitors have a cardio-protective effect in non-diabetic patients with cardiomyopathy.

AHU377+Valsartan (LCZ696) Modulates Renin-Angiotensin System (RAS) in the Cardiac of Female Spontaneously Hypertensive Rats Compared With Valsartan

BACKGROUND

Hypertension is a major cause of death and morbidity worldwide and is increasing in prevalence. The Renin-angiotensin system (RAS) is the most common mechanism involved in the pathophysiology of hypertension. Understanding the mechanism of the pathophysiologic processes will help direct potential therapeutic strategies to treat hypertension and improve cardiac function. Recently, a novel drug LCZ696 containing both an angiotensin receptor blocker valsartan and a neprilysin inhibitor (AHU377) has shown a promising effect on the treatment of hypertension. However, the effects of LCZ696 on the expression of main components of RAS, namely, angiotensin-converting enzyme (ACE), angiotensin-converting enzyme 2 (ACE2), angiotensin II type 1 receptor (AT1 R), angiotensin II type 2 receptor (AT2 R), and angiotensin (1-7) receptor/Mas receptor (MasR) remain unclear. The aim of the present study was to evaluate the effects of LCZ696 on the protective arms of RAS in the cardiac tissue when compared with valsartan under the equal inhibition of AT1 R. We hypothesized that the superior effects of LCZ696 may contribute to its greater effect on the RAS than valsartan.

MATERIALS AND METHODS

Sixteen-week-old female spontaneously hypertensive rats (SHRs) were used in this study. Wistar-Kyoto (WKY) rats were used as controls. All rats were randomly divided into LCZ696 (n = 10), valsartan (n = 10), SHR (n = 10), and WKY (n = 10) groups under a 12-hour dark and 12-hour light cycle and provided with regular chow diet and water. The tail-cuff method was performed to measure blood pressure. Cardiac function was assessed by echocardiography.

RESULTS

The blood pressure value was lower in LCZ696 than valsartan in SHR after 12 weeks of treatment. Further, LCZ696 inhibits the ACE and AT1 R protein expression in the cardiac of SHR and significantly upregulate the protective axis of RAS components, including ACE2, MasR, and AT2 R. Left ventricular AT2 R messenger RNA (mRNA) expression was higher in the LCZ696+SHR group compared with valsartan. In addition, real-time polymerase chain reaction analysis revealed that LCZ696 enhanced the mRNA expression of antihypertensive components AT2 R, ACE2, and MasR and decreased the expression of AT1 R. However, only AT2 R and ACE2 mRNA expressions have a statistical difference between the LCZ696 and valsartan groups. No difference was observed in the mRNA expression of ACE and MasR. The stronger positive signal of transforming growth factor β in the left ventricle was inhibited in each administrated group compared with SHR groups.

CONCLUSIONS

LCZ696 ameliorates the vasoconstrictor axis of the RAS AT1 R and stimulate the protective arm effectors, ACE2 and AT2 R, as well as reverses the compensatory upregulation of neuronal nitric oxide synthase and endothelial nitric oxide synthase in SHR. These findings suggest the mechanistic insight of the cardiac-protective and greater hypotensive effects of LCZ696.

Anti-fibrotic Actions of Roselle Extract in Rat Model of Myocardial Infarction

Heart failure-associated morbidity and mortality is largely attributable to extensive and unregulated cardiac remodelling. Roselle (Hibiscus sabdariffa) calyces are enriched with natural polyphenols known for antioxidant and anti-hypertensive effects, yet its effects on early cardiac remodelling in post myocardial infarction (MI) setting are still unclear. Thus, the aim of this study was to investigate the actions of roselle extract on cardiac remodelling in rat model of MI. Male Wistar rats (200-300 g) were randomly allotted into three groups: Control, MI, and MI + Roselle. MI was induced with isoprenaline (ISO) (85 mg/kg, s.c) for two consecutive days followed by roselle treatment (100 mg/kg, orally) for 7 days. Isoprenaline administration showed changes in heart weight to body weight (HW/BW) ratio. MI was especially evident by the elevated cardiac injury marker, troponin-T, and histological observation. Upregulation of plasma levels and cardiac gene expression levels of inflammatory cytokines such as interleukin (IL)-6 and IL-10 was seen in MI rats. A relatively high percentage of fibrosis was observed in rat heart tissues with over-expression of collagen (Col)-1 and Col-3 genes following isoprenaline-induced MI. On top of that, cardiomyocyte areas were larger in heart tissues of MI rats with upregulation of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) gene expression, indicating cardiac hypertrophy. Interestingly, roselle supplementation attenuated elevation of plasma troponin-T, IL-6, IL10, and gene expression level of IL-10. Furthermore, reduction of cardiac fibrosis and hypertrophy were observed. In conclusion, roselle treatment was able to limit early cardiac remodelling in MI rat model by alleviating inflammation, fibrosis, and hypertrophy; hence, the potential application of roselle in early adjunctive treatment to prevent heart failure.

Quercetin Prevents In Vivo and In Vitro Myocardial Hypertrophy Through the Proteasome-GSK-3 Pathway

PURPOSE

Quercetin, a flavonoid, has been reported to ameliorate cardiovascular diseases, such as cardiac hypertrophy. However, the mechanism is not completely understood. In this study, a mechanism related to proteasome-glycogen synthesis kinase 3 (GSK-3) was elucidated in rats and primary neonatal cardiomyocytes.

METHODS

Rats were subjected to sham or constriction of abdominal aorta surgery groups and treated with or without quercetin for 8 weeks. Angiotensin II (Ang II)-induced primary cardiomyocytes were cultured with quercetin treatment or not for 48 h. Echocardiography, real-time RT-PCR, histology, immunofluorescence, and Western blotting were conducted. Proteasome activities were also detected using a fluorescent peptide substrate.

RESULTS

Echocardiography showed that quercetin prevented constriction of abdominal aorta-induced cardiac hypertrophy and improved the cardiac diastolic function. In addition, quercetin also significantly reduced the Ang II-induced hypertrophic surface area and atrial natriuretic factor (ANF) mRNA level in primary cardiomyocytes. Proteasome activities were obviously inhibited in the quercetin-treated group both in vivo and in vitro. Quercetin also decreased the levels of proteasome subunit beta type (PSMB) 1, PSMB2, and PSMB5 of the 20S proteasome as well as the levels of proteasome regulatory particle (Rpt) 1 and Rpt4 of the 19S proteasome. In particular, the PSMB5 level in the nucleus was reduced after quercetin treatment. Furthermore, phosphorylated GSK-3α/β (inactivation of GSK-3) was decreased, which means that GSK-3 activity was increased. The phosphorylation levels of upstream AKT (PKB (protein kinase B)) and liver kinase B1/AMP activated protein kinase (LKB1/AMPKα) and those of downstream extracellular signal-regulated kinase (ERK), histone H3, β-catenin, and GATA binding protein 4 (GATA4) were reduced after quercetin treatment, while hypertrophy was reversed after treatment with the GSK-3 inhibitor.

CONCLUSION

In summary, quercetin prevents cardiac hypertrophy, which is related to proteasome inhibition and activation of GSK-3α/β. Upstream (AKT, LKB1/AMPKα) and downstream hypertrophic factors, such as ERK, histone H3, β-catenin, and GATA4, may also be involved.

Suppression of angiotensin II-induced pathological changes in heart and kidney by the caveolin-1 scaffolding domain peptide

Dysregulation of the renin-angiotensin system leads to systemic hypertension and maladaptive fibrosis in various organs. We showed recently that myocardial fibrosis and the loss of cardiac function in mice with transverse aortic constriction (TAC) could be averted by treatment with the caveolin-1 scaffolding domain (CSD) peptide. Here, we used angiotensin II (AngII) infusion (2.1 mg/kg/day for 2 wk) in mice as a second model to confirm and extend our observations on the beneficial effects of CSD on heart and kidney disease. AngII caused cardiac hypertrophy (increased heart weight to body weight ratio (HW/BW) and cardiomyocyte cross-sectional area); fibrosis in heart and kidney (increased levels of collagen I and heat shock protein-47 (HSP47)); and vascular leakage (increased levels of IgG in heart and kidney). Echocardiograms of AngII-infused mice showed increased left ventricular posterior wall thickness (pWTh) and isovolumic relaxation time (IVRT), and decreased ejection fraction (EF), stroke volume (SV), and cardiac output (CO). CSD treatment (i.p. injections, 50 μg/mouse/day) of AngII-infused mice significantly suppressed all of these pathological changes in fibrosis, hypertrophy, vascular leakage, and ventricular function. AngII infusion increased β1 and β3 integrin levels and activated Pyk2 in both heart and kidney. These changes were also suppressed by CSD. Finally, bone marrow cell (BMC) isolated from AngII-infused mice showed hyper-migration toward SDF1. When AngII-infused mice were treated with CSD, BMC migration was reduced to the basal level observed in cells from control mice. Importantly, CSD did not affect the AngII-induced increase in blood pressure (BP), indicating that the beneficial effects of CSD were not mediated via normalization of BP. These results strongly indicate that CSD suppresses AngII-induced pathological changes in mice, suggesting that CSD can be developed as a treatment for patients with hypertension and pressure overload-induced heart failure.

Anti-hypertrophy effect of atorvastatin on myocardium depends on AMPK activation-induced miR-143-3p suppression via Foxo1

Left ventricular hypertrophy (LVH) is a pathological characteristic shared by distinct heart disorders. Atorvastatin is employed as a lipid lowering agent and its heart protection effect has been recently reported as well. Thus, the current study attempted to validate the anti-hypertrophy effect of atorvastatin as well as the associated mechanism. Hypertrophic feature was induced in rats using transverse aortic constriction (TAC) method and in cardiomyocytes using angiotensin II (Ang II). Then the animals and cells were treated with atorvastatin and the effect on cardiac weight and structure as well as cell viability, surface area, and apoptosis was assessed. The mechanism associated with the anti-hypertrophy effect of atorvastatin was further explored by focusing on the AMPK/Foxo1/miR-143-3p axis. The results showed that the administration of atorvastatin significantly suppressed TAC-induced heart weight increase and attenuated cardiac structure deteriorations in rats. In in vitro assays, atorvastatin increased cell viability, and reduced cell surface area and apoptosis in Ang II-treated H9c2 cells. At molecular level, atorvastatin activated AMPK, which further promoted Foxo1 activation and suppressed miR-143-3p level. The key role of AMPK during atorvastatin treatment was further validated by subjecting Ang II-treated H9c2 cells to co-incubation of atorvastatin and Compound C, which blocked the pro-survival and anti-hypertrophy effect of atorvastatin on H9c2 cells. The findings outlined in the current study confirmed the anti-hypertrophy effect of atorvastatin and provided a preliminary explanation on the mechanism associated with the treatment: the protective effect of atorvastatin on myocardium against hypertrophy depended on miR-143-3p inhibition via AMPK and Foxo1 activation.

Carboxyl-Terminal Modulator Protein Ameliorates Pathological Cardiac Hypertrophy by Suppressing the Protein Kinase B Signaling Pathway

Background

Carboxyl‐terminal modulator protein (CTMP) has been implicated in cancer, brain injury, and obesity. However, the role of CTMP in pathological cardiac hypertrophy has not been identified.

Methods and Results

In this study, decreased expression of CTMP was observed in both human failing hearts and murine hypertrophied hearts. To further explore the potential involvement of CTMP in pathological cardiac hypertrophy, cardiac‐specific CTMP knockout and overexpression mice were generated. In vivo experiments revealed that CTMP deficiency exacerbated the cardiac hypertrophy, fibrosis, and function induced by pressure overload, whereas CTMP overexpression alleviated the response to hypertrophic stimuli. Consistent with the in vivo results, adenovirus‐mediated gain‐of‐function or loss‐of‐function experiments showed that CTMP also exerted a protective effect against hypertrophic responses to angiotensin II in vitro. Mechanistically, CTMP ameliorated pathological cardiac hypertrophy through the blockade of the protein kinase B signaling pathway. Moreover, inhibition of protein kinase B activation with LY294002 rescued the deteriorated effect in aortic banding–treated cardiac‐specific CTMP knockout mice.

Conclusions

Taken together, these findings imply, for the first time, that increasing the cardiac expression of CTMP may be a novel therapeutic strategy for pathological cardiac hypertrophy.

Relaxin Family Member Insulin-Like Peptide 6 Ameliorates Cardiac Fibrosis and Prevents Cardiac Remodeling in Murine Heart Failure Models

BACKGROUND

The insulin/insulin-like growth factor/relaxin family represents a group of structurally related but functionally diverse proteins. The family member relaxin-2 has been evaluated in clinical trials for its efficacy in the treatment of acute heart failure. In this study, we assessed the role of insulin-like peptide 6 (INSL6), another member of this protein family, in murine heart failure models using genetic loss-of-function and protein delivery methods.

METHODS AND RESULTS

Insl6-deficient and wild-type (C57BL/6N) mice were administered angiotensin II or isoproterenol via continuous infusion with an osmotic pump or via intraperitoneal injection once a day, respectively, for 2 weeks. In both models, Insl6-knockout mice exhibited greater cardiac systolic dysfunction and left ventricular dilatation. Cardiac dysfunction in the Insl6-knockout mice was associated with more extensive cardiac fibrosis and greater expression of fibrosis-associated genes. The continuous infusion of chemically synthesized INSL6 significantly attenuated left ventricular systolic dysfunction and cardiac fibrosis induced by isoproterenol infusion. Gene expression profiling suggests liver X receptor/retinoid X receptor signaling is activated in the isoproterenol-challenged hearts treated with INSL6 protein.

CONCLUSIONS

Endogenous Insl6 protein inhibits cardiac systolic dysfunction and cardiac fibrosis in angiotensin II- and isoproterenol-induced cardiac stress models. The administration of recombinant INSL6 protein could have utility for the treatment of heart failure and cardiac fibrosis.

Protective Roles of Interferon-γ in Cardiac Hypertrophy Induced by Sustained Pressure Overload

BACKGROUND

A clear understanding of the molecular mechanisms underlying hemodynamic stress-initiated cardiac hypertrophy is important for preventing heart failure. Interferon-γ (IFN-γ) has been suggested to play crucial roles in various diseases other than immunological disorders by modulating the expression of myriad genes. However, the involvement of IFN-γ in the pathogenesis of cardiac hypertrophy still remains unclear.

METHODS AND RESULTS

In order to elucidate the roles of IFN-γ in pressure overload-induced cardiac pathology, we subjected Balb/c wild-type (WT) or IFN-γ-deficient (Ifng-/-) mice to transverse aortic constriction (TAC). Three weeks after TAC, Ifng-/- mice developed more severe cardiac hypertrophy, fibrosis, and dysfunction than WT mice. Bone marrow-derived immune cells including macrophages were a source of IFN-γ in hearts after TAC. The activation of PI3K/Akt signaling, a key signaling pathway in compensatory hypertrophy, was detected 3 days after TAC in the left ventricles of WT mice and was markedly attenuated in Ifng-/- mice. The administration of a neutralizing anti-IFN-γ antibody abrogated PI3K/Akt signal activation in WT mice during compensatory hypertrophy, while that of IFN-γ activated PI3K/Akt signaling in Ifng-/- mice. TAC also induced the phosphorylation of Stat5, but not Stat1 in the left ventricles of WT mice 3 days after TAC. Furthermore, IFN-γ induced Stat5 and Akt phosphorylation in rat cardiomyocytes cultured under stretch conditions. A Stat5 inhibitor significantly suppressed PI3K/Akt signaling activation in the left ventricles of WT mice, and aggravated pressure overload-induced cardiac hypertrophy.

CONCLUSIONS

The IFN-γ/Stat5 axis may be protective against persistent pressure overload-induced cardiac hypertrophy by activating the PI3K/Akt pathway.

Does dapagliflozin regress left ventricular hypertrophy in patients with type 2 diabetes? A prospective, double-blind, randomised, placebo-controlled study

BACKGROUND

Patients with diabetes have a two to fourfold increased risk for development of and death from cardiovascular disease [CVD]. The current oral hypoglycaemic agents result in limited reduction in this cardiovascular risk. Sodium glucose linked co-transporter type 2 [SGLT2] inhibitors are a relatively new class of antidiabetic agent that have been shown to have potential cardiovascular benefits. In support of this, the EMPA-REG trial showed a striking 38% and 35% reduction in cardiovascular mortality and heart failure [HF] hospitalisation respectively. The exact mechanism (s) responsible for these effects remain (s) unclear. One potential mechanism is regression of Left ventricular hypertrophy (LVH).

METHODS

The DAPA-LVH trial is a prospective, double-blind, randomised, placebo-controlled 'proof of concept' single-centre study that has been ongoing since January 2017. It is designed specifically to assess whether the SGLT2 inhibitor dapagliflozin regresses left ventricular [LV] mass in patients with diabetes and left ventricular hypertrophy [LVH]. We are utilising cardiac and abdominal magnetic resonance imaging [MRI] and ambulatory blood pressure monitoring to quantify the cardiovascular and systemic effects of dapagliflozin 10 mg once daily against standard care over a 1 year observation period. The primary endpoint is to detect the changes in LV mass. The secondary outcomes are to assess the changes in, LV volumes, blood pressure, weight, visceral and subcutaneous fat.

DISCUSSION

This trial will be able to determine if SGLT2 inhibitor therapy reduces LV mass in patient with diabetes and LVH thereby strengthening their position as oral hypoglycaemic agents with cardioprotective benefits.

TRIAL REGISTRATION

Clinical Trials.gov: NCT02956811 . Registered November 2016.

Osteopontin RNA aptamer can prevent and reverse pressure overload-induced heart failure

AIMS

Cardiac myocyte hypertrophy, the main compensatory response to chronic stress in the heart often progresses to a state of decompensation that can lead to heart failure. Osteopontin (OPN) is an effector for extracellular signalling that induces myocyte growth and fibrosis. Although increased OPN activity has been observed in stressed myocytes and fibroblasts, the detailed and long term effects of blocking OPN signalling on the heart remain poorly defined. Targeting cardiac OPN protein by an RNA aptamer may be beneficial for tuning down OPN pathologic signalling. We aimed to demonstrate the therapeutic effects of an OPN RNA aptamer on cardiac dysfunction.

METHODS AND RESULTS

In vivo, we show that in a mouse model of pressure overload, treating at the time of surgeries with an OPN aptamer prevented cardiomyocyte hypertrophy and cardiac fibrosis, blocked OPN downstream signalling (PI3K and Akt phosphorylation), reduced expression of extracellular matrix (Lum, Col3a1, Fn1) and hypertrophy (Nppa, Nppb) genes, and prevented cardiac dysfunction. Treating at two months post-surgeries with the OPN aptamer reversed cardiac dysfunction and fibrosis and myocyte hypertrophy. While genetic homozygous deletion of OPN reduced myocardial wall thickness, surprisingly cardiac function and myocardial fibrosis, specifically collagen deposition and myofibroblast infiltration, were worse compared with wild type mice at three months of pressure overload.

CONCLUSION

Taken together, these data demonstrate that tuning down cardiac OPN signalling by an OPN RNA aptamer is a novel and effective approach for preventing cardiac hypertrophy and fibrosis, improving cardiac function, and reversing pressure overload-induced heart failure.

Protective effects of low-dose rosuvastatin on isoproterenol-induced chronic heart failure in rats by regulation of DDAH-ADMA-NO pathway

AIMS

Cardiovascular disease is the leading cause of death with high morbidity and mortality, and chronic heart failure is the terminal phase of it. This study aimed to investigate the protective effects of the low-dose rosuvastatin on isoproterenol-induced chronic heart failure and to explore the possible related mechanisms.

METHODS

Male Sprague Dawley rats were given isoproterenol 5 mg/kg once a day for 7 days to establish heart failure model by subcutaneous injection. Simultaneously, low-dose rosuvastatin (5 mg/kg) was orally administrated from day 1 to day 14. Protective effects were evaluated by hemodynamic parameter, histopathological variables, serum asymmetric dimethylarginine (ADMA), cardiac troponin I (cTnI), brain natriuretic peptide (BNP) and myocardial nitric oxide (NO), and the levels of dimethylarginine dimethylaminohydrolase 2 (DDAH2), arginine methyltransferases 1 (PRMT1) and endothelial nitric oxide synthase (eNOS) expression were analyzed.

RESULTS

Therapeutic rosuvastatin (5 mg/kg) significantly attenuated isoproterenol-induced hypertrophy, remodeling and dysfunction of ventricle, reduced the increased serum content of ADMA, cTnI, and BNP, and elevated myocardial NO in rats (P<.05). Besides, rosuvastatin also significantly inhibited fibrosis of myocardium, normalized the increased PRMT1 and decreased DDAH2 expression.

CONCLUSIONS

Low-dose rosuvastatin exerted cardioprotective effects on isoproterenol-induced heart failure in rats by modulating DDAH-ADMA-NO pathway, and it may present the new therapeutic value in ameliorating chronic heart failure.

Effectiveness of Chlorthalidone Plus Amiloride for the Prevention of Hypertension: The PREVER-Prevention Randomized Clinical Trial

BACKGROUND

Prehypertension is associated with higher cardiovascular risk, target organ damage, and incidence of hypertension. The Prevention of Hypertension in Patients with PreHypertension (PREVER-Prevention) trial aimed to evaluate the efficacy and safety of a low-dose diuretic for the prevention of hypertension and end-organ damage.

METHODS AND RESULTS

This randomized, parallel, double-blind, placebo-controlled trial was conducted in 21 Brazilian academic medical centers. Participants with prehypertension who were aged 30 to 70 years and who did not reach optimal blood pressure after 3 months of lifestyle intervention were randomized to a chlorthalidone/amiloride combination pill or placebo and were evaluated every 3 months during 18 months of treatment. The primary outcome was incidence of hypertension. Development or worsening of microalbuminuria, new-onset diabetes mellitus, and reduction of left ventricular mass were secondary outcomes. Participant characteristics were evenly distributed by trial arms. The incidence of hypertension was significantly lower in 372 study participants allocated to diuretics compared with 358 allocated to placebo (hazard ratio 0.56, 95% CI 0.38-0.82), resulting in a cumulative incidence of 11.7% in the diuretic arm versus 19.5% in the placebo arm (P=0.004). Adverse events; levels of blood glucose, glycosylated hemoglobin, creatinine, and microalbuminuria; and incidence of diabetes mellitus were no different between the 2 arms. Left ventricular mass assessed through Sokolow-Lyon voltage and voltage-duration product decreased to a greater extent in participants allocated to diuretic therapy compared with placebo (P=0.02).

CONCLUSIONS

A combination of low-dose chlorthalidone and amiloride effectively reduces the risk of incident hypertension and beneficially affects left ventricular mass in patients with prehypertension.

CLINICAL TRIAL REGISTRATION

URL: http://www.ClinicalTrials.gov, www.ensaiosclinicos.gov. Unique identifiers: NCT00970931, RBR-74rr6s.

Xinmailong mitigated epirubicin-induced cardiotoxicity via inhibiting autophagy

ETHNOPHARMACOLOGICAL RELEVANCE

Using insects, such as the cockroach, for the treatment of disease has a long history in traditional Chinese medicine. Xinmailong (XML) Injection, a bioactive composite extracted from Periplaneta americana (a species of cockroach), shows reasonable protective effects against cardiovascular injury and was approved for the use in the treatment of cardiac dysfunction in 2006, yet its cardio protective mechanisms remain unclear.

AIM

The present study aims to examine the protective effects of XML against epirubicin-induced cardiotoxicity in vivo and determine its underlying mechanisms.

MATERIALS AND METHODS

The chemical characteristics of XML were identified using high performance liquid chromatography (HPLC). Rats were intraperitoneally injected with epirubicin and then treated with XML for 14 days. Survival rate, echocardiography, electrocardiographic recordings and Masson staining were used to evaluate the cardioprotective activity of XML. Western blot and quantitative real time reverse transcriptase polymerase chain reaction (RT-PCR) analyses were used to investigate the molecular mechanisms underlying the actions of XML.

RESULTS

XML treatment significantly enhanced the survival rate of rats from epirubicin-induced heart failure. XML prevented left ventricle dilatation, improved cardiac function. Furthermore, treatment with XML also significantly inhibited the accumulation of collagen, reduced the levels of mRNA for matrix metalloproteinases-9 (Mmp9) and transforming growth factor-β 1(Tgfb1). This action of XML therefore might be responsible, at least in part, for the attenuation of cardiac fibrotic remodeling. XML inhibited autophagy as evidenced by the decreased accumulation of Beclin1 and autophagy related 7 (Atg7), which are necessary to form autophagosome structures. Protein kinase B (PKB/Akt), phosphatidylinositol 3 kinase (PI3K) and B cell lymphoma2 (Bcl2) levels were up-regulated, while significantly decreased protein levels for phosphorylated P38 and extracellular regulated protein kinases 1/2 (Erk1/2) were observed in the XML treated rats. The autophagy related results suggested that the increase in PI3K/Akt levels and inhibition of the phosphorylation of P38 MAPK and Erk1/2 contributed to the anti-autophagic activity of XML.

CONCLUSIONS

Our data suggest that XML may be effective for mitigating epirubicin-induced cardiomyopathy and inhibits autophagy via activating the PI3K/Akt signaling pathway and inhibiting the Erk1/2 and P38 MAPK signaling pathways.