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Malnutrition is highly prevalent in patients with heart failure (HF), but the precise impact of dietary energy deficiency on HF patients' clinical outcomes is not known. We investigated the associations between inadequate calorie intake and adverse clinical events in 145 stable outpatients with chronic HF who had a history of hospitalization due to worsening HF. To assess the patients' dietary pattern, we used a brief self-administered diet-history questionnaire (BDHQ). Inadequate calorie intake was defined as <60% of the estimated energy requirement. In the total chronic HF cohort, the median calorie intake was 1628 kcal/day. Forty-four patients (30%) were identified as having an inadequate calorie intake. A Kaplan-Meier analysis revealed that the patients with inadequate calorie intake had significantly worse clinical outcomes including all-cause death and HF-related hospitalization during the 1-year follow-up period versus those with adequate calorie intake (20% vs. 5%, p < 0.01). A multivariate logistic regression analysis showed that inadequate calorie intake was an independent predictor of adverse clinical events after adjustment for various factors that may influence patients' calorie intake. Among patients with chronic HF, inadequate calorie intake was associated with an increased risk of all-cause mortality and rehospitalization due to worsening HF. However, our results are preliminary and larger studies with direct measurements of dietary calorie intake and total energy expenditure are needed to clarify the intrinsic nature of this relationship.

Background: We recently reported that treatment with rhBDNF (recombinant human brain-derived neurotrophic factor) improved the reduced exercise capacity of mice with heart failure (HF) after myocardial infarction (MI). Since BDNF is reported to enhance fatty acid oxidation, we herein conducted an in vivo investigation to determine whether the improvement in exercise capacity is due to the enhancement of the fatty acid oxidation of skeletal muscle via the AMPKα-PGC1α (adenosine monophosphate-activated protein kinase-ɑ-proliferator-activated receptor-r coactivator-1ɑ) axis., Methods: MI and sham operations were conducted in C57BL/6J mice. Two weeks postsurgery, we randomly divided the MI mice into groups treated with rhBDNF or vehicle for 2 weeks. AMPKα-PGC1α signaling and mitochondrial content in the skeletal muscle of the mice were evaluated by Western blotting and transmission electron microscopy. Fatty acid β-oxidation was examined by high-resolution respirometry using permeabilized muscle fiber. BDNF-knockout mice were treated with 5-aminoimidazole-4-carboxamide-1-beta-d-riboruranoside, an activator of AMPK., Results: The rhBDNF treatment significantly increased the expressions of phosphorylated AMPKα and PGC1α protein and the intermyofibrillar mitochondrial density in the MI mice. The lowered skeletal muscle mitochondrial fatty acid oxidation was significantly improved in the rhBDNF-treated MI mice. The reduced exercise capacity and mitochondrial dysfunction of the BDNF-knockout mice were improved by 5-aminoimidazole-4-carboxamide-1-beta-d-riboruranoside., Conclusions: Beneficial effects of BDNF on the exercise capacity of mice with HF are mediated through an enhancement of fatty acid oxidation via the activation of AMPKα-PGC1α in skeletal muscle. BDNF may become a therapeutic option to improve exercise capacity as an alternative or adjunct to exercise training.

Epirubicin-based chemotherapy carries a risk of inducing heart failure, although the frequency is rare. Bevacizumab, an anti-vascular endothelial growth factor monoclonal antibody, has recently been widely used in patients with recurrent breast cancer as a first-line chemotherapeutic agent. Heart failure or arterial thromboembolism has been reported as a rare cardiovascular complication of bevacizumab. We herein report a breast cancer patient with reversible cancer therapeutics-related cardiac dysfunction associated with bevacizumab and epirubicin complicating intracardiac thrombi in the left atrium and left ventricle. This case underscores the importance of tailored medical planning according to the individual status in patients receiving anti-cancer therapies.

Background: Skeletal muscle is quantitatively and qualitatively impaired in patients with heart failure (HF), which is closely linked to lowered exercise capacity. Ultrasonography (US) for skeletal muscle has emerged as a useful, noninvasive tool to evaluate muscle quality and quantity. Here we investigated whether muscle quality based on US-derived echo intensity (EI) is associated with exercise capacity in patients with HF., Methods and Results: Fifty-eight patients with HF (61 ± 12 years) and 28 control subjects (58 ± 14 years) were studied. The quadriceps femoris echo intensity (QEI) was significantly higher and the quadriceps femoris muscle thickness (QMT) was significantly lower in the patients with HF than the controls (88.3 ± 13.4 vs 81.1 ± 7.5, P= .010; 5.21 ± 1.10 vs 6.54 ±1.34 cm, P< .001, respectively). By univariate analysis, QEI was significantly correlated with age, peak oxygen uptake (VO 2 ), and New York Heart Association class in the HF group. A multivariable analysis revealed that the QEI was independently associated with peak VO 2 after adjustment for age, gender, body mass index, and QMT: β-coefficient = -11.80, 95%CI (-20.73, -2.86), P= .011., Conclusion: Enhanced EI in skeletal muscle was independently associated with lowered exercise capacity in HF. The measurement of EI is low-cost, easily accessible, and suitable for assessment of HF-related alterations in skeletal muscle quality., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Loop diuretics are widely used for the management of fluid retention in patients with heart failure (HF). Sarcopenia, defined as decreased skeletal muscle mass, is frequently present in patients with HF and is associated with poor prognosis. The effects of loop diuretics on skeletal muscle in HF patients have not been fully elucidated. Here, we investigated the impact of loop diuretics on the skeletal muscle mass in patients with HF., Methods: We conducted a subanalysis of a cross-sectional study from 10 hospitals evaluating 155 patients with HF (age 67 ± 13 yrs, 69% men)., Results: We compared the HF patients who were treated with loop diuretics (n = 120) with the patients who were not (n = 35). The thigh and arm circumferences were significantly small in the group treated with loop diuretics compared to those not so treated (39.9 ± 4.8 vs. 43.5 ± 6.9 cm, p < 0.001 and 26.7 ± 3.5 vs. 28.9 ± 6.2 cm, p < 0.001, respectively). In a univariate analysis, higher age, lower body mass index, lower hemoglobin, and loop diuretic use were significantly associated with smaller thigh circumference. In a multivariable analysis, the use of loop diuretics was independently associated with smaller thigh circumference (β = -0.51, 95% confidence interval -0.98 to -0.046, p = 0.032)., Conclusion: Loop diuretics are associated with decreased thigh and arm circumferences in patients with HF, independent of the severity of HF. Our findings revealed for the first time the adverse effects of loop diuretics on skeletal muscle wasting. These findings will have a significant impact in clinical practice regarding the frequent use of loop diuretics in HF patients., (Copyright © 2020. Published by Elsevier Ltd.)

A 23-year-old man had progressive muscle weakness and Emery-Dreifuss muscular dystrophy (EDMD) due to a LMNA (lamin A/C) mutation. Congestive heart failure diagnosed at 19 years of age. Maximal drug treatment/cardiac resynchronization failed to improve the cardiac function. He was therefore hospitalized due to heart failure. Despite extracorporeal membrane oxygenation, he developed severe right heart dysfunction and died (multiple organ failure). A cardiac lesion's presence determines the prognosis of EDMD. While there are many arrhythmia reports, few reports on heart failure (particularly severe heart failure requiring cardiac transplantation) have been published. Right heart function monitoring and early ventricular-assist device use plus right heart support considering heart transplantation are important.

Background: In heart failure (HF) management, early ambulation is recommended to prevent physical deconditioning. The effects of delayed ambulation on later clinical outcomes and the factors linked to delayed ambulation in hospitalized HF patients, however, remain unestablished. Methods and Results: We retrospectively investigated 101 patients (mean age, 66±17 years) who were hospitalized for acute decompensated HF. During the mean follow-up of 244±15 days after hospital discharge, 34 patients had cardiovascular events leading to death or unplanned readmission. Patients with cardiovascular events had longer median days to acquire ambulation than those without cardiovascular events (11 days, IQR, 8-20 days vs. 7 days, IQR, 5-15 days, P<0.001). The optimal cut-off period until initiation of ambulation to discriminate cardiovascular events was 8 days, indicating that longer days (≥8 days) to acquire ambulation was associated with higher rates of cardiovascular events, even after adjustment of multiple confounders. On multivariate analysis, age >65 years (odds ratio [OR], 2.49; 95% confidence interval [CI]: 1.04-6.09) and increase in blood urea nitrogen (BUN; OR, 1.04; 95% CI: 1.01-1.08) were independent predictors of delayed ambulation. Conclusions: Delayed ambulation is associated with older age and increased BUN in patients with acute HF. Time to ambulation in the recovery phase of acute HF is important, and delayed ambulation may increase the rate of cardiovascular events after hospital discharge., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2019, THE JAPANESE CIRCULATION SOCIETY.)

Heart failure (HF) is associated with aberrant skeletal muscle impairments, which are closely linked to the severity of HF. A low level of brain-derived neurotrophic factor (BDNF), a myokine produced in the skeletal muscle, is known to be involved in reduced exercise capacity and poor prognosis in HF. However, little is known about the factors or conditions of skeletal muscle associated with BDNF levels. We investigated the association between serum BDNF levels and the skeletal muscle mass and function in HF patients (n = 60, 63 ± 13 years) and age-matched controls (n = 29, 61 ± 16 years). The serum BDNF level was significantly lower in the HF patients compared to the controls (24.9 ± 0.9 versus 28.6 ± 1.3, P = 0.021). In a univariate analysis, BDNF was significantly correlated with the peak oxygen uptake, estimated glomerular filtration rate, 10-m gait speed, and muscle strength, but not with the body mass index or lean mass in the HF group. A multiple linear regression analysis revealed that BDNF was independently associated with muscle strength (β-coefficient = 2.80, 95%CI: 1.89-11.8, P = 0.008). Serum BDNF levels were associated with exercise capacity and skeletal muscle function, but not with muscle mass. These novel findings may suggest that BDNF production is controlled by muscle function and activity and consequently regulates exercise capacity, highlighting the importance of adequate training regarding skeletal muscle in HF patients.

Skeletal muscle (SKM) requires a large amount of energy, which is produced mainly by mitochondria, for their daily functioning. Of the several mitochondrial complexes, it has been reported that the dysfunction of complex II is associated with several diseases, including myopathy. However, the degree to which complex II contributes to ATP production by mitochondria remains unknown. As complex II is not included in supercomplexes, which are formed to produce ATP efficiently, we hypothesized that complex II-linked respiration was lower than that of complex I. In addition, differences in the characteristics of complex I and II activity suggest that different factors might regulate their function. The isolated mitochondria from gastrocnemius muscle was used for mitochondrial respiration measurement and immunoblotting in male C57BL/6J mice. Student paired t-tests were performed to compare means between two groups. A univariate linear regression model was used to determine the correlation between mitochondrial respiration and proteins. Contrary to our hypothesis, complex II-linked respiration was not significantly less than complex I-linked respiration in SKM mitochondria (complex I vs complex II, 3402 vs 2840 pmol/[s × mg]). Complex I-linked respiration correlated with the amount of complex I incorporated in supercomplexes ( r  = 0.727, p  < 0.05), but not with the total amount of complex I subunits. In contrast, complex II-linked respiration correlated with the total amount of complex II ( r  = 0.883, p  < 0.05), but not with the amount of each complex II subunit. We conclude that both complex I and II play important roles in mitochondrial respiration and that the assembly of both supercomplexes and complex II is essential for the normal functioning of complex I and II in mouse SKM mitochondria., Competing Interests: None., (© 2019 Published by Elsevier B.V.)

Although cardiac involvement is rare in polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes (POEMS) syndrome, the clinical course becomes considerably worse on complication with cardiac lesions. The increased release of various cytokines has been observed in the pathogenesis of POEMS syndrome, and serum vascular endothelial growth factor (VEGF) levels are known to be associated with the disease activity. We herein report a patient with POEMS syndrome who showed left ventricular systolic dysfunction and was treated with lenalidmide therapy. Of note, the reduction in extracellular edema in the left ventricular wall was clearly visualized by changes in the native T1 values and extracellular volumes on cardiac magnetic resonance imaging.

Becker muscular dystrophy (BMD) carriers are at risk to developing cardiac dysfunction. The prevalence of female BMD carriers remains underestimated, and the disease progression varies. We herein report the case of a young female BMD carrier who developed dilated cardiomyopathy (DCM) and heart failure without any skeletal muscle signs. Her cardiac dysfunction progressed over a mere two months, resulting in the need for left ventricular assist device implantation. Her case demonstrates that progressive cardiomyopathy can be the only clinical manifestation in some BMD carriers, suggesting the need for a more aggressive implementation of genetic testing in female DCM patients.

Background: Impaired cardiac insulin signalling and high cardiac fatty acid oxidation rates are characteristics of conditions of insulin resistance and diabetic cardiomyopathies. The potential role of liver-derived peptides such as adropin in mediating these changes in cardiac energy metabolism is unclear, despite the fact that in skeletal muscle adropin can preferentially promote glucose metabolism and improve insulin sensitivity., Objectives: To determine the influence of adropin on cardiac energy metabolism, insulin signalling and cardiac efficiency., Methods: C57Bl/6 mice were injected with either vehicle or a secretable form of adropin (450 nmol/kg, i.p.) three times over a 24-h period. The mice were fasted to accentuate the differences between animals in adropin plasma levels before their hearts were isolated and perfused using a working heart system. In addition, direct addition of adropin to the perfusate of ex vivo hearts isolated from non-fasting mice was utilized to investigate the acute effects of the peptide on heart metabolism and ex vivo function., Results: In contrast to the observed fasting-induced predominance of fatty acid oxidation as a source of ATP production in control hearts, insulin inhibition of fatty acid oxidation was preserved by adropin treatment. Adropin-treated mouse hearts also showed a higher cardiac work, which was accompanied by improved cardiac efficiency and enhanced insulin signalling compared to control hearts. Interestingly, acute adropin administration to isolated working hearts also resulted in an inhibition of fatty acid oxidation, accompanied by a robust stimulation of glucose oxidation compared to vehicle-treated hearts. Adropin also increased activation of downstream cardiac insulin signalling. Moreover, both in vivo and ex vivo treatment protocols induced a reduction in the inhibitory phosphorylation of pyruvate dehydrogenase (PDH), the major enzyme of glucose oxidation, and the protein levels of the responsible kinase PDH kinase 4 and the insulin-signalling inhibitory phosphorylation of JNK (p-T 183 /Y 185 ) and IRS-1 (p-S 307 ), suggesting acute receptor- and/or post-translational modification-mediated mechanisms., Conclusions: These results demonstrate that adropin has important effects on energy metabolism in the heart and may be a putative candidate for the treatment of cardiac disease associated with impaired insulin sensitivity., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Alterations in cardiac energy metabolism after a myocardial infarction contribute to the severity of heart failure (HF). Although fatty acid oxidation can be impaired in HF, it is unclear if stimulating fatty acid oxidation is a desirable approach to treat HF. Both immediate and chronic malonyl coenzyme A decarboxylase inhibition, which decreases fatty acid oxidation, improved cardiac function through enhancing cardiac efficiency in a post-myocardial infarction rat that underwent permanent left anterior descending coronary artery ligation. The beneficial effects of MCD inhibition were attributed to a decrease in proton production due to an improved coupling between glycolysis and glucose oxidation.

Background: Although the enhancement of early-diastolic intra-left ventricular pressure difference (IVPD) during exercise is considered to maintain exercise capacity, little is known about their relationship in heart failure (HF)., Methods and Results: Cardiopulmonary exercise testing and exercise-stress echocardiography were performed in 50 HF patients (left ventricular [LV] ejection fraction 39 ± 15%). Echocardiographic images were obtained at rest and submaximal and peak exercise. Color M-mode Doppler images of LV inflow were used to determine IVPD. Thirty-five patients had preserved exercise capacity (peak oxygen consumption [VO 2 ] ≥14 mL·kg -1 ·min -1 ; group 1) and 15 patients had reduced exercise capacity (group 2). During exercise, IVPD increased only in group 1 (group 1: 1.9 ± 0.9 mm Hg at rest, 4.1 ± 2.0 mm Hg at submaximum, 4.7 ± 2.1 mm Hg at peak; group 2: 1.9 ± 0.8 mm Hg at rest, 2.1 ± 0.9 mm Hg at submaximum, 2.1 ± 0.9 mm Hg at peak). Submaximal IVPD (r = 0.54) and peak IVPD (r = 0.69) were significantly correlated with peak VO 2 . Peak IVPD determined peak VO 2 independently of LV ejection fraction. Moreover, submaximal IVPD could well predict the reduced exercise capacity., Conclusion: Early-diastolic IVPD during exercise was closely associated with exercise capacity in HF. In addition, submaximal IVPD could be a useful predictor of exercise capacity without peak exercise in HF patients., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Early ambulation has been shown to be associated with shorter hospital stay and better clinical outcomes in patients with acute heart failure (HF). Early mobilization program in combination with structured exercise training is recommended, but has yet to be developed and implemented in HF. Methods and Results: We developed a progressive mobilization program for HF patients that classifies the mobilization process into 7 stages based on disease condition and physical function. We retrospectively analyzed 136 patients with acute HF (80±11 years), who were assigned either to the mobilization program (intervention group, n=75) or to usual care (control group, n=61). The program was safely implemented without any adverse events. Hospital stay was significantly reduced in the intervention group compared with the control group (33±25 vs. 51±36 days, P<0.01). The intervention group had higher activities of daily living (ADL) score at discharge evaluated using the Barthel index (64±38 vs. 49±36, P<0.05). The intervention group also had a higher percentage of discharge to home (71% vs. 52%, P<0.05) and a lower rate of HF-related readmission (16% vs. 36%, P<0.05) compared with the control group. Conclusions: The progressive mobilization program for acute HF was feasible and was associated with better ADL and reduced hospital stay, leading to improvement of clinical outcome., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2019, THE JAPANESE CIRCULATION SOCIETY.)

Recent studies have proposed that elevated branched-chain amino acids (BCAAs) may induce insulin resistance (IR) in muscle secondary to increased BCAA oxidation inhibiting glucose oxidation (GO) and fatty acid oxidation (FAO). However, BCAA oxidation rates have not been assessed in muscle IR, and cardiac FAO rates are actually already elevated in obesity-associated IR. We therefore directly examined cardiac BCAA oxidation in mice fed a high-fat diet (HFD) to induce insulin resistance to better understand the role of cardiac BCAA oxidation in cardiac IR. BCAA oxidation, GO, FAO, and glycolysis were measured in isolated working hearts from mice fed either a low-fat diet (LFD) or HFD for 10 wk. Insulin stimulation of cardiac GO and inhibition of FAO were blunted in HFD mice, resulting in a marked increase in FAO contribution to ATP production compared with LFD mice hearts (71.2% vs. 37.1%, respectively). Surprisingly, cardiac BCAA oxidation rate was reduced in HFD compared with LFD mice (33.5 ± 3.4 vs. 56.7 ± 7.1 nmol·min -1 ·g dry wt -1 , respectively, P < 0.05, n = 9/group). In addition, BCAA oxidation contributed ~1% of the ATP production of the heart, and, as a result, alterations in BCAA oxidation could not significantly impact either GO or FAO rates. However, the decrease in BCAA oxidation was accompanied by an increase in BCAA concentration and impaired insulin signaling. These results suggest that cardiac IR is not due to an increase in BCAA oxidation and subsequent inhibition of GO and FAO. Rather, we propose that an inhibition of BCAA oxidation rate contributes to IR by leading to increased BCAA concentration, which negatively impacts insulin signaling.

Background: Drug rash with eosinophilia and systemic symptoms (DRESS) syndrome is a severe adverse drug reaction accompanied by multiple organ dysfunction. Myocarditis is a manifestation, and once acute necrotizing eosinophilic myocarditis (ANEM) develops, the mortality rate is high., Case Summary: We report the case of a 37-year-old man who developed myocarditis associated with DRESS syndrome after starting treatment with lithium and quetiapine for bipolar disorder. At that time, he presented with fever, morbilliform eruption, lymphadenopathy, eosinophilia with atypical lymphocytes, and liver dysfunction; bipolar drugs were discontinued and oral prednisolone begun. Four months later, he was admitted to our institution with worsening skin rash and dyspnoea. Transthoracic echocardiography revealed reduced systolic function in both ventricles, and endocardial biopsy indicated hypersensitivity myocarditis. Cardiac function was temporarily normalized by high-dose prednisolone. However, the inflammation was persistent as shown by a re-elevation of troponin T and fall of left ventricular ejection fraction several months later; in addition, 18 F-fluoro-deoxyglucose positron emission tomography with chest computed tomography (FDG-PET/CT) showed focal FDG uptake in the left ventricle. Despite additional treatment with mycophenolate mofetil, the cardiac function deteriorated further, and the patient eventually manifested refractory heart failure classified as New York Heart Association (NYHA) Class III. Myocardial biopsy showed myocyte necrosis associated with ANEM., Discussion: This is the first case report of DRESS-associated myocarditis due to treatment for bipolar disorder. Although the pathophysiology remains incompletely understood, lithium and/or quetiapine can induce refractory myocarditis in DRESS syndrome. Regular measurements of troponin T and FDG-PET/CT are useful for assessing disease progression in DRESS-associated myocarditis.

Background: Exercise intolerance is a common clinical feature and is linked to poor prognosis in patients with heart failure (HF). Skeletal muscle dysfunction, including impaired energy metabolism in the skeletal muscle, is suspected to play a central role in this intolerance, but the underlying mechanisms remain elusive. Lysine acetylation, a recently identified post-translational modification, has emerged as a major contributor to the derangement of mitochondrial metabolism. We thus investigated whether mitochondrial protein acetylation is associated with impaired skeletal muscle metabolism and lowered exercise capacity in both basic and clinical settings of HF., Methods: We first conducted a global metabolomic analysis to determine whether plasma acetyl-lysine is a determinant factor for peak oxygen uptake (peak VO 2 ) in HF patients. We then created a murine model of HF (n = 11) or sham-operated (n = 11) mice with or without limited exercise capacity by ligating a coronary artery, and we tested the gastrocnemius tissues by using mass spectrometry-based acetylomics. A causative relationship between acetylation and the activity of a metabolic enzyme was confirmed in in vitro studies., Results: The metabolomic analysis verified that acetyl-lysine was the most relevant metabolite that was negatively correlated with peak VO 2 (r = -0.81, P < 0.01). At 4 weeks post-myocardial infarction HF, a treadmill test showed lowered work (distance × body weight) and peak VO 2 in the HF mice compared with the sham-operated mice (11 ± 1 vs. 23 ± 1 J, P < 0.01; 143 ± 5 vs. 159 ± 3 mL/kg/min, P = 0.01; respectively). As noted, the protein acetylation of gastrocnemius mitochondria was 48% greater in the HF mice than the sham-operated mice (P = 0.047). Acetylproteomics identified the mitochondrial enzymes involved in fatty acid β-oxidation (FAO), the tricarboxylic acid cycle, and the electron transport chain as targets of acetylation. In parallel, the FAO enzyme (β-hydroxyacyl CoA dehydrogenase) activity and fatty acid-driven mitochondrial respiration were reduced in the HF mice. This alteration was associated with a decreased expression of mitochondrial deacetylase, Sirtuin 3, because silencing of Sirtuin 3 in cultured skeletal muscle cells resulted in increased mitochondrial acetylation and reduced β-hydroxyacyl CoA dehydrogenase activity., Conclusions: Enhanced mitochondrial protein acetylation is associated with impaired FAO in skeletal muscle and reduced exercise capacity in HF. Our results indicate that lysine acetylation is a crucial mechanism underlying deranged skeletal muscle metabolism, suggesting that its modulation is a potential approach for exercise intolerance in HF., (© 2018 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of the Society on Sarcopenia, Cachexia and Wasting Disorders.)

Alterations in cardiac energy metabolism are an important contributor to the cardiac pathology associated with obesity, diabetes, and heart failure. High rates of fatty acid β-oxidation with cardiac insulin resistance represent a cardiac metabolic hallmark of diabetes and obesity, while a marginal decrease in fatty acid oxidation and a prominent decrease in insulin-stimulated glucose oxidation are commonly seen in the early stages of heart failure. Alterations in post-translational control of energy metabolic processes have recently been identified as an important contributor to these metabolic changes. In particular, lysine acetylation of non-histone proteins, which controls a diverse family of mitochondrial metabolic pathways, contributes to the cardiac energy derangements seen in obesity, diabetes, and heart failure. Lysine acetylation is controlled both via acetyltransferases and deacetylases (sirtuins), as well as by non-enzymatic lysine acetylation due to increased acetyl CoA pool size or dysregulated nicotinamide adenine dinucleotide (NAD + ) metabolism (which stimulates sirtuin activity). One of the important mitochondrial acetylation targets are the fatty acid β-oxidation enzymes, which contributes to alterations in cardiac substrate preference during the course of obesity, diabetes, and heart failure, and can ultimately lead to cardiac dysfunction in these disease states. This review will summarize the role of lysine acetylation and its regulatory control in the context of mitochondrial fatty acid β-oxidation. The functional contribution of cardiac protein lysine acetylation to the shift in cardiac energy substrate preference that occurs in obesity, diabetes, and especially in the early stages of heart failure will also be reviewed. This article is part of a Special Issue entitled: The role of post-translational protein modifications on heart and vascular metabolism edited by Jason R.B. Dyck & Jan F.C. Glatz., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Obesity and diabetes are major public health problems, and are linked to the development of heart failure. Emerging data highlight the importance of alterations in cardiac energy metabolism as a major contributor to cardiac dysfunction related to obesity and diabetes. Increased rates of fatty acid oxidation and decreased rates of glucose utilization are two prominent changes in cardiac energy metabolism that occur in obesity and diabetes. This metabolic profile is probably both a cause and consequence of a prominent cardiac insulin resistance, which is accompanied by a decrease in both cardiac function and efficiency, and by the accumulation of potentially toxic lipid metabolites in the heart that can further exaggerate insulin resistance and cardiac dysfunction. The high cardiac fatty acid oxidation rates seen in obesity and diabetes are attributable to several factors, including: 1) increased fatty acid supply and uptake into the cardiomyocyte, 2) increased transcription of fatty acid metabolic enzymes, 3) decreased allosteric control of mitochondrial fatty acid uptake and fatty acid oxidation, and 4) increased post-translational acetylation control of various fatty acid oxidative enzymes. Emerging evidence suggests that therapeutic approaches aimed at switching the balance of cardiac energy substrate preference from fatty acid oxidation to glucose use can prevent cardiac dysfunction associated with obesity and diabetes. Modulating acetylation control of fatty acid oxidative enzymes is also a potentially attractive strategy, although presently this is limited to precursors of nicotinamide adenine or nonspecific activators of deacetylation such as resveratrol. This review will focus on the metabolic alterations in the heart that occur in obesity and diabetes, as well as on the molecular mechanisms controlling these metabolic changes. This article is part of a Special Issue entitled: Heart Lipid Metabolism edited by G.D. Lopaschuk., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Dramatic maturational changes in cardiac energy metabolism occur in the newborn period, with a shift from glycolysis to fatty acid oxidation. Acetylation and succinylation of lysyl residues are novel posttranslational modifications involved in the control of cardiac energy metabolism. We investigated the impact of changes in protein acetylation/succinylation on the maturational changes in energy metabolism of 1-, 7-, and 21-day-old rabbit hearts. Cardiac fatty acid β-oxidation rates increased in 21-day vs. 1- and 7-day-old hearts, whereas glycolysis and glucose oxidation rates decreased in 21-day-old hearts. The fatty acid oxidation enzymes, long-chain acyl-CoA dehydrogenase (LCAD) and β-hydroxyacyl-CoA dehydrogenase (β-HAD), were hyperacetylated with maturation, positively correlated with their activities and fatty acid β-oxidation rates. This alteration was associated with increased expression of the mitochondrial acetyltransferase, general control of amino acid synthesis 5 like 1 (GCN5L1), since silencing GCN5L1 mRNA in H9c2 cells significantly reduced acetylation and activity of LCAD and β-HAD. An increase in mitochondrial ATP production rates with maturation was associated with the decreased acetylation of peroxisome proliferator-activated receptor-γ coactivator-1α, a transcriptional regulator for mitochondrial biogenesis. In addition, hypoxia-inducible factor-1α, hexokinase, and phosphoglycerate mutase expression declined postbirth, whereas acetylation of these glycolytic enzymes increased. Phosphorylation rather than acetylation of pyruvate dehydrogenase (PDH) increased in 21-day-old hearts, accounting for the low glucose oxidation postbirth. A maturational increase was also observed in succinylation of PDH and LCAD. Collectively, our data are the first suggesting that acetylation and succinylation of the key metabolic enzymes in newborn hearts play a crucial role in cardiac energy metabolism with maturation., (Copyright © 2016 the American Physiological Society.)

Insulin resistance can occur as a consequence of heart failure (HF). Activation of the renin-angiotensin system (RAS) may play a crucial role in this phenomenon. We thus investigated the effect of a direct renin inhibitor, aliskiren, on insulin resistance in HF after myocardial infarction (MI). MI and sham operation were performed in male C57BL/6J mice. The mice were divided into 4 groups and treated with sham-operation (Sham, n=10), sham-operation and aliskiren (Sham+Aliskiren; 10mg/kg/day, n=10), MI (n=11), or MI and aliskiren (MI+Aliskiren, n=11). After 4 weeks, MI mice showed left ventricular dilation and dysfunction, which were not affected by aliskiren. The percent decrease of blood glucose after insulin load was significantly smaller in MI than in Sham (14±5% vs. 36±2%), and was ameliorated in MI+Aliskiren (34±5%) mice. Insulin-stimulated serine-phosphorylation of Akt and glucose transporter 4 translocation were decreased in the skeletal muscle of MI compared to Sham by 57% and 69%, and both changes were ameliorated in the MI+Aliskiren group (91% and 94%). Aliskiren administration in MI mice significantly inhibited plasma renin activity and angiotensin II (Ang II) levels. Moreover, (pro)renin receptor expression and local Ang II production were upregulated in skeletal muscle from MI and were attenuated in MI+Aliskiren mice, in tandem with a decrease in superoxide production and NAD(P)H oxidase activities. In conclusion, aliskiren ameliorated insulin resistance in HF by improving insulin signaling in the skeletal muscle, at least partly by inhibiting systemic and (pro)renin receptor-mediated local RAS activation, and subsequent NAD(P)H oxidase-induced oxidative stress., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Background: Transverse aortic constriction (TAC) operation is used as an experimental model of left ventricular (LV) hypertrophy and LV failure in mice. The severity of LV remodeling or failure may depend on the degree of TAC, but is variable among operated animals. Therefore, we tried to identify the optimal diameter of TAC to create this model with ease and high reproducibility., Methods and Results: To produce TAC in C57BL/6J mice (7-9 weeks, body weight 19-26 g, n = 109), a 7-0 nylon suture ligature was tightly tied around the transverse aorta against needles with 3 different diameters (mm); 0.40, 0.385 and 0.375. LV wall thickness, end-diastolic dimension, fractional shortening were measured by echocardiography. At 4 weeks after TAC, no mouse with the 0.400 mm gauge progressed in LV failure. The 0.385 mm pin gauge mouse kept a more survival rate compared with the 0.375 mm (59% vs 48%), representing same efficient in LV failure. With the 0.385 mm pin gauge, hearts of mice remained LV hypertrophy at 1 week after TAC, followed by LV failure at 4 weeks., Conclusion: TAC with the diameter of 0.385 mm can effectively induce the transition from LV hypertrophy to failure in mice with relatively preserved survival.

Background: Brain-derived neurotropic factor (BDNF) is involved in cardiovascular diseases as well as skeletal muscle energy metabolism and depression. We investigated whether serum BDNF level was associated with prognosis in patients with heart failure (HF)., Methods and Results: We measured the serum BDNF level in 58 patients with HF (59.2 ± 13.7 years old, New York Heart Association functional class I-III) at baseline, and adverse events, including all cardiac deaths and HF rehospitalizations, were recorded during the median follow-up of 20.3 months. In a univariate analysis, serum BDNF levels were significantly associated with peak oxygen capacity (β = 0.547; P = .003), anaerobic threshold (β = 0.929; P = .004), and log minute ventilation/carbon dioxide production slope (β = -10.15; P = .005), but not Patient Health Questionnaire scores (β = -0.099; P = .586). A multivariate analysis demonstrated that serum BDNF level was an independent prognostic factor of adverse events (hazard ratio 0.41, 95% confidence interval 0.20-0.84; P = .003). The receiver operating characteristic curve demonstrated that low levels of BDNF (<17.4 ng/mL) were associated with higher rates of adverse events compared with high levels of BDNF (≥17.4 ng/mL; log rank test: P < .001)., Conclusions: Decreased serum BDNF levels were significantly associated with adverse outcomes in HF patients, suggesting that these levels can be a useful prognostic biomarker., (Copyright © 2015 Elsevier Inc. All rights reserved.)

We previously reported that insulin resistance was induced by the impairment of insulin signaling in the skeletal muscle from heart failure (HF) via NAD(P)H oxidase-dependent oxidative stress. (Pro)renin receptor [(P)RR] is involved in the activation of local renin-angiotensin system and subsequent oxidative stress. We thus examined whether (P)RR inhibitor, handle region peptide (HRP), could ameliorate insulin resistance in HF after myocardial infarction (MI) by improving oxidative stress and insulin signaling in the skeletal muscle. C57BL6J mice were divided into four groups: sham operated (Sham, n = 10), Sham treated with HRP (Sham+HRP, 0.1 mg·kg(-1)·day(-1), n = 10), MI operated (MI, n = 10), and MI treated with HRP (MI+HRP, 0.1 mg/kg/day, n = 10). After 4 wk, MI mice showed left ventricular dysfunction, which was not affected by HRP. (P)RR was upregulated in the skeletal muscle after MI (149% of sham, P < 0.05). The decrease in plasma glucose after insulin load was smaller in MI than in Sham (21 ± 2 vs. 44 ± 3%, P < 0.05), and was greater in MI+HRP (38 ± 2%, P < 0.05) than in MI. Insulin-stimulated serine phosphorylation of Akt and glucose transporter 4 translocation were decreased in the skeletal muscle from MI by 48 and 49% of Sham, both of which were ameliorated in MI+HRP. Superoxide production and NAD(P)H oxidase activities were increased in MI, which was inhibited in MI+HRP. HRP ameliorated insulin resistance associated with HF by improving insulin signaling via the inhibition of NAD(P)H oxidase-induced superoxide production in the skeletal muscle. The (P)RR pathway is involved in the development of insulin resistance, at least in part, via the impairment of insulin signaling in the skeletal muscle from HF., (Copyright © 2014 the American Physiological Society.)

Exercise training (EX) and diet restriction (DR) are essential for effective management of obesity and insulin resistance in diabetes mellitus. However, whether these interventions ameliorate the limited exercise capacity and impaired skeletal muscle function in diabetes patients remains unexplored. Therefore, we investigated the effects of EX and/or DR on exercise capacity and skeletal muscle function in diet-induced diabetic mice. Male C57BL/6J mice that were fed a high-fat diet (HFD) for 8 weeks were randomly assigned for an additional 4 weeks to 4 groups: control, EX, DR, and EX+DR. A lean group fed with a normal diet was also studied. Obesity and insulin resistance induced by a HFD were significantly but partially improved by EX or DR and completely reversed by EX+DR. Although exercise capacity decreased significantly with HFD compared with normal diet, it partially improved with EX and DR and completely reversed with EX+DR. In parallel, the impaired mitochondrial function and enhanced oxidative stress in the skeletal muscle caused by the HFD were normalized only by EX+DR. Although obesity and insulin resistance were completely reversed by DR with an insulin-sensitizing drug or a long-term intervention, the exercise capacity and skeletal muscle function could not be normalized. Therefore, improvement in impaired skeletal muscle function, rather than obesity and insulin resistance, may be an important therapeutic target for normalization of the limited exercise capacity in diabetes. In conclusion, a comprehensive lifestyle therapy of exercise and diet normalizes the limited exercise capacity and impaired muscle function in diabetes mellitus.