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1.
Proc Natl Acad Sci U S A ; 119(41): e2203628119, 2022 10 11.
Article in English | MEDLINE | ID: mdl-36201541

ABSTRACT

Heart failure (HF) is a leading cause of death and repeated hospitalizations and often involves cardiac mitochondrial dysfunction. However, the underlying mechanisms largely remain elusive. Here, using a mouse model in which myocardial infarction (MI) was induced by coronary artery ligation, we show the metabolic basis of mitochondrial dysfunction in chronic HF. Four weeks after ligation, MI mice showed a significant decrease in myocardial succinyl-CoA levels, and this decrease impaired the mitochondrial oxidative phosphorylation (OXPHOS) capacity. Heme synthesis and ketolysis, and protein levels of several enzymes consuming succinyl-CoA in these events, were increased in MI mice, while enzymes synthesizing succinyl-CoA from α-ketoglutarate and glutamate were also increased. Furthermore, the ADP-specific subunit of succinyl-CoA synthase was reduced, while its GDP-specific subunit was almost unchanged. Administration of 5-aminolevulinic acid, an intermediate in the pathway from succinyl-CoA to heme synthesis, appreciably restored succinyl-CoA levels and OXPHOS capacity and prevented HF progression in MI mice. Previous reports also suggested the presence of succinyl-CoA metabolism abnormalities in cardiac muscles of HF patients. Our results identified that changes in succinyl-CoA usage in different metabolisms of the mitochondrial energy production system is characteristic to chronic HF, and although similar alterations are known to occur in healthy conditions, such as during strenuous exercise, they may often occur irreversibly in chronic HF leading to a decrease in succinyl-CoA. Consequently, nutritional interventions compensating the succinyl-CoA consumption are expected to be promising strategies to treat HF.


Subject(s)
Heart Failure , Myocardial Infarction , Acyl Coenzyme A , Adenosine Diphosphate/metabolism , Aminolevulinic Acid , Energy Metabolism , Glutamates/metabolism , Heart Failure/metabolism , Heme/metabolism , Humans , Ketoglutaric Acids , Oxidative Phosphorylation
2.
BMC Pharmacol Toxicol ; 22(1): 27, 2021 05 07.
Article in English | MEDLINE | ID: mdl-33962676

ABSTRACT

BACKGROUND: Doxorubicin (DOX) is widely used as an effective chemotherapeutic agent for cancers; however, DOX induces cardiac toxicity, called DOX-induced cardiomyopathy. Although DOX-induced cardiomyopathy is known to be associated with a high cumulative dose of DOX, the mechanisms of its long-term effects have not been completely elucidated. Pioglitazone (Pio) is presently contraindicated in patients with symptomatic heart failure owing to the side effects. The concept of drug repositioning led us to hypothesize the potential effects of Pio as a premedication before DOX treatment, and to analyze this hypothesis in mice. METHODS: First, for the hyperacute (day 1) and acute (day 7) DOX-induced dysfunction models, mice were fed a standard diet with or without 0.02% (wt/wt) Pio for 5 days before DOX treatment (15 mg/kg body weight [BW] via intraperitoneal [i.p.] administration). The following 3 treatment groups were analyzed: standard diet + vehicle (Vehicle), standard diet + DOX (DOX), and Pio + DOX. Next, for the chronic model (day 35), the mice were administrated DOX once a week for 5 weeks (5 mg/kg BW/week, i.p.). RESULTS: In the acute phase after DOX treatment, the percent fractional shortening of the left ventricle (LV) was significantly decreased in DOX mice. This cardiac malfunction was improved in Pio + DOX mice. In the chronic phase, we observed that LV function was preserved in Pio + DOX mice. CONCLUSIONS: Our findings may provide a new pathophysiological explanation by which Pio plays a role in the treatment of DOX-induced cardiomyopathy, but the molecular links between Pio and DOX-induced LV dysfunction remain largely elusive.


Subject(s)
Antibiotics, Antineoplastic/adverse effects , Cardiotonic Agents/therapeutic use , Doxorubicin/adverse effects , Pioglitazone/therapeutic use , Ventricular Dysfunction, Left/prevention & control , Animals , Male , Mice, Inbred C57BL , Myocardium/pathology , Premedication , Ventricular Dysfunction, Left/chemically induced , Ventricular Dysfunction, Left/metabolism , Ventricular Dysfunction, Left/pathology , Ventricular Function, Left/drug effects
3.
Exp Physiol ; 106(8): 1785-1793, 2021 08.
Article in English | MEDLINE | ID: mdl-33998079

ABSTRACT

NEW FINDINGS: What is the central question of this study? We questioned whether an angiotensin-converting enzyme (ACE) inhibitor prevents skeletal muscle fibrosis in diabetic mice. What is the main finding and its importance? Administration of ACE inhibitor prevents the increase in skeletal muscle fibrosis during the early phase after induction of diabetes by streptozotocin. Our findings might provide a new therapeutic target for skeletal muscle abnormalities in diabetes. ABSTRACT: Fibrosis is characterized by the excessive production and accumulation of extracellular matrix components, including collagen. Although the extracellular matrix is an essential component of skeletal muscle, fibrosis can have negative effects on muscle function. Skeletal muscle fibrosis was shown to be increased in spontaneously hypertensive rats and to be prevented by an angiotensin-converting enzyme (ACE) inhibitor, an antihypertensive drug, in dystrophic mice or a mouse model of myocardial infarction. In this study, we therefore analysed whether (1) there is increased skeletal muscle fibrosis in streptozotocin (STZ)-induced diabetic mice, and (2) a preventive effect on skeletal muscle fibrosis by administration of an ACE inhibitor. Skeletal muscle fibrosis was significantly increased in STZ-induced diabetic mice compared with control mice from 2 to 14 days post-STZ. The ACE inhibitor prevented both skeletal muscle fibrosis and the reduction in muscle function in STZ-treated mice. Our study demonstrated that administration of an ACE inhibitor prevents the increase in skeletal muscle fibrosis during the early phase after onset of diabetes. Our findings might provide a new therapeutic target for skeletal muscle abnormalities in diabetes. Future studies are required to clarify whether skeletal muscle fibrosis is also linked directly to physical activity.


Subject(s)
Angiotensin-Converting Enzyme Inhibitors , Diabetes Mellitus, Experimental , Angiotensin-Converting Enzyme Inhibitors/pharmacology , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Animals , Antihypertensive Agents/pharmacology , Diabetes Mellitus, Experimental/drug therapy , Fibrosis , Mice , Muscle, Skeletal , Rats
4.
Commun Biol ; 4(1): 138, 2021 01 29.
Article in English | MEDLINE | ID: mdl-33514783

ABSTRACT

Heart failure (HF) occurs frequently among older individuals, and dysfunction of cardiac mitochondria is often observed. We here show the cardiac-specific downregulation of a certain mitochondrial component during the chronological aging of mice, which is detrimental to the heart. MitoNEET is a mitochondrial outer membrane protein, encoded by CDGSH iron sulfur domain 1 (CISD1). Expression of mitoNEET was specifically downregulated in the heart and kidney of chronologically aged mice. Mice with a constitutive cardiac-specific deletion of CISD1 on the C57BL/6J background showed cardiac dysfunction only after 12 months of age and developed HF after 16 months; whereas irregular morphology and higher levels of reactive oxygen species in their cardiac mitochondria were observed at earlier time points. Our results suggest a possible mechanism by which cardiac mitochondria may gradually lose their integrity during natural aging, and shed light on an uncharted molecular basis closely related to age-associated HF.


Subject(s)
Heart Failure/metabolism , Membrane Proteins/deficiency , Mitochondria, Heart/metabolism , Myocytes, Cardiac/metabolism , Ventricular Dysfunction, Left/metabolism , Age Factors , Animals , Heart Failure/genetics , Heart Failure/physiopathology , Iron-Binding Proteins/genetics , Male , Membrane Proteins/genetics , Mice, Inbred C57BL , Mice, Knockout , Mitochondria, Heart/genetics , Oxidative Stress , Reactive Oxygen Species/metabolism , Time Factors , Ventricular Dysfunction, Left/genetics , Ventricular Dysfunction, Left/physiopathology , Ventricular Function, Left
5.
Cardiovasc Res ; 117(3): 805-819, 2021 02 22.
Article in English | MEDLINE | ID: mdl-32402072

ABSTRACT

AIMS: Exercise intolerance in patients with heart failure (HF) is partly attributed to skeletal muscle abnormalities. We have shown that reactive oxygen species (ROS) play a crucial role in skeletal muscle abnormalities, but the pathogenic mechanism remains unclear. Xanthine oxidase (XO) is reported to be an important mediator of ROS overproduction in ischaemic tissue. Here, we tested the hypothesis that skeletal muscle abnormalities in HF are initially caused by XO-derived ROS and are prevented by the inhibition of their production. METHODS AND RESULTS: Myocardial infarction (MI) was induced in male C57BL/6J mice, which eventually led to HF, and a sham operation was performed in control mice. The time course of XO-derived ROS production in mouse skeletal muscle post-MI was first analysed. XO-derived ROS production was significantly increased in MI mice from Days 1 to 3 post-surgery (acute phase), whereas it did not differ between the MI and sham groups from 7 to 28 days (chronic phase). Second, mice were divided into three groups: sham + vehicle (Sham + Veh), MI + vehicle (MI + Veh), and MI + febuxostat (an XO inhibitor, 5 mg/kg body weight/day; MI + Feb). Febuxostat or vehicle was administered at 1 and 24 h before surgery, and once-daily on Days 1-7 post-surgery. On Day 28 post-surgery, exercise capacity and mitochondrial respiration in skeletal muscle fibres were significantly decreased in MI + Veh compared with Sham + Veh mice. An increase in damaged mitochondria in MI + Veh compared with Sham + Veh mice was also observed. The wet weight and cross-sectional area of slow muscle fibres (higher XO-derived ROS) was reduced via the down-regulation of protein synthesis-associated mTOR-p70S6K signalling in MI + Veh compared with Sham + Veh mice. These impairments were ameliorated in MI + Feb mice, in association with a reduction of XO-derived ROS production, without affecting cardiac function. CONCLUSION: XO inhibition during the acute phase post-MI can prevent skeletal muscle abnormalities and exercise intolerance in mice with HF.


Subject(s)
Enzyme Inhibitors/pharmacology , Exercise Tolerance/drug effects , Febuxostat/pharmacology , Muscle, Skeletal/drug effects , Muscular Atrophy/prevention & control , Myocardial Infarction/drug therapy , Xanthine Oxidase/antagonists & inhibitors , Animals , Cell Hypoxia , Cell Line , Disease Models, Animal , Male , Mice, Inbred C57BL , Mitochondria, Muscle/drug effects , Mitochondria, Muscle/enzymology , Mitochondria, Muscle/pathology , Muscle Fibers, Skeletal/drug effects , Muscle Fibers, Skeletal/enzymology , Muscle Fibers, Skeletal/pathology , Muscle Strength/drug effects , Muscle, Skeletal/enzymology , Muscle, Skeletal/pathology , Muscle, Skeletal/physiopathology , Muscular Atrophy/enzymology , Muscular Atrophy/pathology , Muscular Atrophy/physiopathology , Myocardial Infarction/enzymology , Myocardial Infarction/pathology , Myocardial Infarction/physiopathology , Reactive Oxygen Species/metabolism , Ribosomal Protein S6 Kinases, 70-kDa/metabolism , TOR Serine-Threonine Kinases/metabolism , Time Factors , Xanthine Oxidase/metabolism
6.
Circ Heart Fail ; 14(1): e005890, 2021 01.
Article in English | MEDLINE | ID: mdl-33356364

ABSTRACT

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 ß-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.


Subject(s)
AMP-Activated Protein Kinases/drug effects , Brain-Derived Neurotrophic Factor/pharmacology , Exercise Tolerance/drug effects , Fatty Acids/metabolism , Heart Failure/metabolism , Muscle, Skeletal/drug effects , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/drug effects , AMP-Activated Protein Kinases/metabolism , Aminoimidazole Carboxamide/analogs & derivatives , Aminoimidazole Carboxamide/pharmacology , Animals , Brain-Derived Neurotrophic Factor/genetics , Heart Failure/genetics , Heart Failure/physiopathology , Humans , Male , Mice , Mice, Knockout , Microscopy, Electron, Transmission , Mitochondria/drug effects , Mitochondria/metabolism , Mitochondria/ultrastructure , Muscle, Skeletal/metabolism , Muscle, Skeletal/ultrastructure , Myocardial Infarction/metabolism , Myocardial Infarction/physiopathology , Oxidation-Reduction/drug effects , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/metabolism , Recombinant Proteins , Ribonucleosides/pharmacology
7.
Asian J Endosc Surg ; 14(3): 401-407, 2021 Jul.
Article in English | MEDLINE | ID: mdl-33084236

ABSTRACT

INTRODUCTION: Endoscopic intragastric balloon (IGB) placement has been performed in Japan since 2004. The nationwide surveys were repeatedly carried out to confirm the effectiveness and safety of IGB in Japan. We herein present the accumulated results. METHODS: Twenty-six Japanese endoscopists personally imported products of the BioEnterics Intragastric Balloon (BIB)/Orbera system after completing the training courses in Japan. Mail surveys were posted to them every 2 years from 2010. This study included the accumulated data of the six surveys, and excluded data from non-Japanese patients and the Orbera365 data. RESULTS: Between 2004 and 2019, 399 obese Japanese patients underwent IGB treatment using the BIB/Orbera system. The incidence rates of early removal of IGB within 1 week and complications due to IGB were 4.8% and 6.1%, respectively. The average percent excess weight loss (%EWL) and percent total weight loss (%TWL) at IGB removal were 46.6% and 11.5%, and successful weight loss, defined as %EWL ≥ 25% or %TWL ≥ 10%, was achieved in 65.6% or 54.5% of the patients, respectively. Multivariate analyses revealed that older age and larger saline filling volume were independent predictors of successful weight loss. At 1 year after IGB removal, successful weight loss defined by the %EWL and %TWL was maintained in 44.7% and 34.1% of the patients, respectively. CONCLUSION: IGB therapy using the BIB/Orbera system has been safely and effectively performed in Japan. The successful weight loss may be associated with older age and larger saline filling volume.


Subject(s)
Gastric Balloon , Obesity/surgery , Adult , Body Mass Index , Device Removal , Female , Gastroscopy , Humans , Japan , Male , Middle Aged , Treatment Outcome , Weight Loss
8.
Cardiovasc Diabetol ; 19(1): 142, 2020 09 19.
Article in English | MEDLINE | ID: mdl-32950064

ABSTRACT

BACKGROUND: Although type 2 diabetes mellitus (T2DM) is one of the most frequent comorbidities in patients with chronic heart failure (CHF), the effects of T2DM on the exercise capacity of CHF patients are fully unknown. Here, we tested the hypothesis that the coexistence of T2DM lowers CHF patients' peak aerobic capacity. METHODS: We retrospectively analyzed the cases of 275 Japanese CHF patients with non-reduced ejection fraction (left ventricular ejection fraction [LVEF] ≥ 40%) or reduced EF (LVEF < 40%) who underwent cardiopulmonary exercise testing. We divided them into diabetic and nondiabetic groups in each CHF cohort. RESULTS: The mean peak oxygen uptake (VO2) value was 16.87 mL/kg/min in the non-reduced LVEF cohort and 15.52 mL/kg/min in the reduced LVEF cohort. The peak VO2 was lower in the diabetics versus the nondiabetics in the non-reduced LVEF cohort with the mean difference (95% confidence interval [95% CI]) of - 0.93 (- 1.82 to - 0.04) mL/kg/min and in the reduced LVEF cohort with the mean difference of - 1.05 (- 1.96 to - 0.15) mL/kg/min, after adjustment for age-squared, gender, anemia, renal function, LVEF, and log B-type natriuretic peptide (BNP). The adjusted VO2 at anaerobic threshold (AT), a submaximal aerobic capacity, was also decreased in the diabetic patients with both non-reduced and reduced LVEFs. Intriguingly, the diabetic patients had a lower adjusted peak O2 pulse than the nondiabetic patients in the reduced LVEF cohort, but not in the non-reduced LVEF cohort. A multivariate analysis showed that the presence of T2DM was an independent predictor of lowered peak VO2 in CHF patients with non-reduced LVEF and those with reduced LVEF. CONCLUSIONS: T2DM was associated with lowered peak VO2 in CHF patients with non-reduced or reduced LVEF. The presence of T2DM has a negative impact on CHF patients' exercise capacity, and the degree of impact is partly dependent on their LV systolic function.


Subject(s)
Anaerobic Threshold/physiology , Diabetes Mellitus, Type 2/physiopathology , Heart Failure/physiopathology , Oxygen Consumption/physiology , Adult , Aged , Cardiomyopathy, Dilated , Case-Control Studies , Diabetes Mellitus, Type 2/complications , Exercise Tolerance , Female , Heart Failure/complications , Humans , Male , Middle Aged , Myocardial Ischemia , Stroke Volume
10.
Intern Med ; 59(9): 1133-1139, 2020.
Article in English | MEDLINE | ID: mdl-32378654

ABSTRACT

Objective Intragastric balloon (IGB) therapy is a low-invasion treatment for obesity. Recently, a low-carbohydrate diet has shown effectiveness for encouraging weight loss, but whether or not a low-carbohydrate diet improves the efficacy of IGB therapy remains unclear. Therefore, we examined the effectiveness of a low-carbohydrate diet compared with a calorie-restricted diet in combination with IGB therapy. Methods A prospective study was conducted on 51 patients who had undergone IGB therapy from October 2012 to December 2017. Overall, 31 of the 51 patients were included in this study (12-month assessment after IGB placement). These 31 cases consisted of 18 IGB plus low-carbohydrate diet and 13 IGB plus calorie-restricted diet. We compared the two groups with respect to body weight loss as outcomes. Results At 12 months after IGB placement, the body weight was significantly lower than that observed at baseline in both the IGB plus low-carbohydrate diet group (baseline 101.9±25.8 kg, 12 months 88.2±21.9 kg) (p<0.0001) and the IGB plus calorie-restricted diet group (baseline 103.5±17.0 kg, 12 months 89.1±6.2 kg) (p<0.005). The percentage of excess weight loss in the IGB plus low-carbohydrate diet group was slightly higher than that in the IGB plus calorie-restricted diet group, but there was no significant difference between the 2 groups at 12 months after IGB placement (IGB plus low-carbohydrate 49.9±60.0%, IGB plus calorie-restricted diet 33.1±27.0%). Conclusion Our study demonstrated that both a low-carbohydrate diet and a calorie-restricted diet were effective interventions for weight reduction in combination with IGB therapy.


Subject(s)
Diet, Carbohydrate-Restricted , Gastric Balloon , Obesity, Morbid/therapy , Body Weight , Female , Humans , Male , Middle Aged , Obesity, Morbid/diet therapy , Prospective Studies , Treatment Outcome , Weight Loss
11.
Biochem Biophys Rep ; 21: 100717, 2020 Mar.
Article in English | MEDLINE | ID: mdl-31890905

ABSTRACT

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.

12.
Eur J Pharmacol ; 866: 172810, 2020 Jan 05.
Article in English | MEDLINE | ID: mdl-31738936

ABSTRACT

Decreased exercise capacity, which is an independent predictor of the poor prognosis of patients with heart failure (HF), is attributed to markedly impaired skeletal muscle mitochondrial function and fatty acid oxidation. Previous studies reported that the administration of an inhibitor of sodium-glucose cotransporter 2 (SGLT2) increases ketone body production and fat utilization in type 2 diabetic mice. In this study, we investigated the effects of SGLT2 inhibitor administration on exercise endurance and skeletal muscle mitochondrial function with fatty acid oxidation in a murine model of HF after the induction of myocardial infarction (MI). Two weeks post-MI, HF mice were divided into 2 groups, i.e., with or without treatment with the SGLT2 inhibitor empagliflozin (Empa, 300 mg/kg of food). Consistent with previous studies, urinary glucose and blood beta-hydroxybutyrate levels were increased in the HF+Empa mice compared with the sham and HF mice 4 weeks after the start of Empa administration. Exercise endurance capacity was limited in the HF mice but was ameliorated in the HF+Empa mice, without any effects on cardiac function, food intake, spontaneous physical activity, skeletal muscle strength, and skeletal muscle weight. Mitochondrial oxidative phosphorylation capacity with fatty acid substrates was reduced in the skeletal muscle of HF mice, and this decrease was ameliorated in the HF+Empa mice. Our results demonstrate that SGLT2 inhibitors may be novel therapeutics against reduced exercise endurance capacity in HF, by improving mitochondrial fatty acid oxidation in skeletal muscle.


Subject(s)
Benzhydryl Compounds/pharmacology , Fatty Acids/metabolism , Glucosides/pharmacology , Heart Failure/physiopathology , Muscle, Skeletal/drug effects , Muscle, Skeletal/metabolism , Physical Conditioning, Animal/physiology , Physical Endurance/drug effects , 3-Hydroxybutyric Acid/blood , Adipose Tissue/drug effects , Adipose Tissue/pathology , Animals , Blood Glucose/metabolism , Disease Models, Animal , Heart Failure/blood , Heart Failure/metabolism , Heart Failure/pathology , Insulin/blood , Male , Mice , Mice, Inbred C57BL , Mitochondria/drug effects , Mitochondria/pathology , Muscle Strength/drug effects , Muscle, Skeletal/pathology , Muscle, Skeletal/physiopathology , Oxidation-Reduction/drug effects , Oxidative Phosphorylation/drug effects , Recovery of Function/drug effects , Sodium-Glucose Transporter 2 Inhibitors/pharmacology
13.
Cell Commun Signal ; 17(1): 128, 2019 10 16.
Article in English | MEDLINE | ID: mdl-31619261

ABSTRACT

BACKGROUND: Linoleic acid is the major fatty acid moiety of cardiolipin, which is central to the assembly of components involved in mitochondrial oxidative phosphorylation (OXPHOS). Although linoleic acid is an essential nutrient, its excess intake is harmful to health. On the other hand, linoleic acid has been shown to prevent the reduction in cardiolipin content and to improve mitochondrial function in aged rats with spontaneous hypertensive heart failure (HF). In this study, we found that lower dietary intake of linoleic acid in HF patients statistically correlates with greater severity of HF, and we investigated the mechanisms therein involved. METHODS: HF patients, who were classified as New York Heart Association (NYHA) functional class I (n = 45), II (n = 93), and III (n = 15), were analyzed regarding their dietary intakes of different fatty acids during the one month prior to the study. Then, using a mouse model of HF, we confirmed reduced cardiolipin levels in their cardiac myocytes, and then analyzed the mechanisms by which dietary supplementation of linoleic acid improves cardiac malfunction of mitochondria. RESULTS: The dietary intake of linoleic acid was significantly lower in NYHA III patients, as compared to NYHA II patients. In HF model mice, both CI-based and CII-based OXPHOS activities were affected together with reduced cardiolipin levels. Silencing of CRLS1, which encodes cardiolipin synthetase, in cultured cardiomyocytes phenocopied these events. Feeding HF mice with linoleic acid improved both CI-based and CII-based respiration as well as left ventricular function, together with an increase in cardiolipin levels. However, although assembly of the respirasome (i.e., CI/CIII2/CIV complex), as well as assembly of CII subunits and the CIII2/CIV complex statistically correlated with cardiolipin levels in cultured cardiomyocytes, respirasome assembly was not notably restored by dietary linoleic acid in HF mice. Therefore, although linoleic acid may significantly improve both CI-based and CII-based respiration of cardiomyocytes, respirasomes impaired by HF were not easily repaired by the dietary intake of linoleic acid. CONCLUSIONS: Dietary supplement of linoleic acid is beneficial for improving cardiac malfunction in HF, but is unable to completely cure HF.


Subject(s)
Electron Transport Complex III/metabolism , Electron Transport Complex II/metabolism , Electron Transport Complex IV/metabolism , Heart Failure/metabolism , Linoleic Acid/pharmacology , Mitochondria, Heart/drug effects , Oxidative Phosphorylation/drug effects , Aged , Animals , Cardiolipins/metabolism , Electron Transport Complex II/chemistry , Female , Heart Failure/pathology , Heart Failure/physiopathology , Humans , Linoleic Acid/metabolism , Male , Mice , Mitochondria, Heart/metabolism , Protein Subunits/metabolism
14.
Sci Rep ; 9(1): 14709, 2019 10 11.
Article in English | MEDLINE | ID: mdl-31605012

ABSTRACT

Systemic oxidative stress plays a key role in the development of chronic heart failure (CHF). We tested the hypothesis that mitochondrial reactive oxygen species (ROS) generation in circulating peripheral blood mononuclear cells (PBMCs) contributes to CHF progression. A total of 31 patients who had a history of hospital admission due to worsening HF were enrolled and grouped as having either mild CHF defined as New York Heart Association (NYHA) functional class I-II or moderate-to-severe CHF defined as NYHA functional class III. ROS levels in PBMC mitochondria were significantly increased in CHF patients with NYHA functional class III compared to those with NYHA functional class I-II, accompanied by impaired mitochondrial respiratory capacity in PBMCs. ROS generation in PBMC mitochondria was positively correlated with urinary 8-hydroxydeoxyguanosine, a systemic oxidative stress marker, in CHF patients. Importantly, mitochondrial ROS generation in PBMCs was directly correlated with plasma levels of B-type natriuretic peptide, a biomarker for severity of HF, and inversely correlated with peak oxygen uptake, a parameter of exercise capacity, in CHF patients. The study showed that ROS generation in PBMC mitochondria was higher in patients with advanced CHF, and it was associated with disease severity and exercise intolerance in CHF patients.


Subject(s)
Exercise Tolerance , Heart Failure/physiopathology , Leukocytes, Mononuclear/metabolism , Mitochondria/metabolism , Reactive Oxygen Species/metabolism , Severity of Illness Index , 8-Hydroxy-2'-Deoxyguanosine/urine , Aged , Biomarkers/blood , Chronic Disease , Exercise Test , Female , Humans , Male , Middle Aged , Natriuretic Peptide, Brain/blood , Oxygen Consumption
15.
Biochem Biophys Res Commun ; 513(3): 708-713, 2019 06 04.
Article in English | MEDLINE | ID: mdl-30987827

ABSTRACT

Neutrophils rapidly migrate to infection sites after the recognition of invaders. During chemotaxis, neutrophils require energy supplied by mitochondria oxidative phosphorylation (OXPHOS), whereas neutrophils rely heavily on glycolysis under normal conditions. Mitochondrial OXPHOS correlates with mitochondrial morphology. Here, we examined the mitochondrial morphology of neutrophil-like differentiated HL-60 cells after chemoattractant N-formyl-Met-Leu-Phe (fMLP) stimulation. We found that mitochondrial morphology changes to a tubular form after fMLP stimulation. Mitochondrial OXPHOS activity and mitochondrial complex II significantly increased after fMLP stimulation. On the other hand, the silencing of mitochondrial fusion protein mitofusin 2 (MFN2) suppresses mitochondrial morphological changes. Furthermore, MFN2 silencing suppressed OXPHOS activation and chemotaxis after fMLP stimulation. These results suggest that MFN2 is involved in chemotaxis of differentiated HL-60 cells depending on mitochondria.


Subject(s)
Chemotaxis, Leukocyte , GTP Phosphohydrolases/metabolism , Mitochondria/metabolism , Mitochondrial Proteins/metabolism , Neutrophils/cytology , HL-60 Cells , Humans , Mitochondria/ultrastructure , Neutrophils/metabolism , Oxidative Phosphorylation
16.
Circ J ; 82(11): 2753-2760, 2018 10 25.
Article in English | MEDLINE | ID: mdl-30175799

ABSTRACT

BACKGROUND: Oxygen uptake (V̇O2) at peak workload and anaerobic threshold (AT) workload are often used for grading heart failure (HF) severity and predicting all-cause mortality. The clinical relevance of respiratory exchange ratio (RER) during exercise, however, is unknown. Methods and Results: We retrospectively studied 295 HF patients (57±15 years, NYHA class I-III) who underwent cardiopulmonary exercise testing. RER was measured at rest; at AT workload; and at peak workload. Peak V̇O2 had an inverse correlation with RER at AT workload (r=-0.256), but not at rest (r=-0.084) or at peak workload (r=0.090). Using median RER at AT workload, we divided the patients into high RER (≥0.97) and low RER (<0.97) groups. Patients with high RER at AT workload were characterized by older age, lower body mass index, anemia, and advanced NYHA class. After propensity score matching, peak V̇O2 tended to be lower in the high-RER than in the low-RER group (14.9±4.5 vs. 16.1±5.0 mL/kg/min, P=0.06). On Kaplan-Meier analysis, HF patients with a high RER at AT workload had significantly worse clinical outcomes, including all-cause mortality and rate of readmission due to HF worsening over 3 years (29% vs. 15%, P=0.01). CONCLUSIONS: High RER during submaximal exercise, particularly at AT workload, is associated with poor clinical outcome in HF patients.


Subject(s)
Exercise Therapy , Heart Failure , Adult , Aged , Disease-Free Survival , Exercise Test , Female , Heart Failure/mortality , Heart Failure/physiopathology , Heart Failure/therapy , Heart Rate , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Respiratory Function Tests , Retrospective Studies , Survival Rate
18.
Surg Endosc ; 29(2): 500-4, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25052125

ABSTRACT

BACKGROUND: A 5-7 day hospital stay is usually needed after endoscopic submucosal dissection (ESD) of gastric tumor because of the possibility of delayed perforation or bleeding. The aim of this study was to evaluate the efficacy of combined use of a single over-the-scope clip (OTSC) and through-the-scope clips (TTSCs) to achieve complete closure of artificial gastric ulcer after ESD. METHODS: We prospectively studied 12 patients with early gastric cancer or gastric adenoma. We performed complete closure of post-ESD artificial gastric ulcer using a combination of a single OTSC and TTSCs. RESULTS: Mean size of post-ESD artificial ulcer was 54.6 mm. The mean operating time for the closure procedure was 15.2 min., and the success rate was 91.7 % (11/12). Patients who underwent complete closure of post-ESD artificial gastric ulcer could be discharged the day after ESD and the closing procedure. CONCLUSIONS: Complete closure of post-ESD artificial gastric ulcer using a combination of a single OTSC and TTSCs is useful for shortening the period of hospitalization and reducing treatment cost.


Subject(s)
Dissection/methods , Gastrectomy/adverse effects , Gastric Mucosa/surgery , Gastroscopy/methods , Stomach Ulcer/surgery , Suture Techniques/instrumentation , Sutures , Aged , Equipment Design , Female , Humans , Male , Middle Aged , Postoperative Complications , Retrospective Studies , Stomach Neoplasms/surgery , Stomach Ulcer/etiology , Treatment Outcome
19.
J UOEH ; 36(4): 265-72, 2014 Dec 01.
Article in Japanese | MEDLINE | ID: mdl-25501758

ABSTRACT

Acute cholecystitis is an inflammatory disease of the gallbladder. Inflammation often remains in the gallbladder, but some patients may take a fatal course with exacerbation of inflammation. Although laparoscopic cholecystectomy is recommended for moderate and severe acute cystitis, sometimes cholecystectomy is impossible in elder patients. Because many elder patients have bad general conditions, cholecystectomy should not be performed. Such patients are generally treated by percutaneous transhepatic gallbladder drainage (PTGBD), but PTGBD has the risk of intra-abdominal bleeding. In previous reports, endoscopic gallbladder stenting (EGBS) has been shown to be an effective strategy in cirrhosis patients with symptomatic cholelithiasis as a bridge to transplantation. Recent studies on EGBS have demonstrated an effective long-term management of acute cholecystitis in elderly patients who are poor surgical candidates. Here, we reviewed EGBS for the management of acute cholecystitis.


Subject(s)
Cholecystitis, Acute/surgery , Endoscopy, Digestive System/methods , Gallbladder/surgery , Stents , Cholecystitis, Acute/diagnosis , Diagnostic Imaging , Endoscopy, Digestive System/adverse effects , Endoscopy, Digestive System/trends , Humans , Prognosis , Stents/adverse effects , Stents/trends
20.
Diabetes Metab Syndr Obes ; 7: 195-201, 2014.
Article in English | MEDLINE | ID: mdl-24966689

ABSTRACT

BACKGROUND: In recent years, the number of people with impaired glucose tolerance (IGT) has increased steadily worldwide. It is clear that the prevention of diabetes is important from the perspective of public health, medical care, and economics. It was recently reported that a low-carbohydrate diet (LCD) is useful for achieving weight loss and glycemic control, but there is no information about the effects of the LCD on IGT. We designed a 7-day in-hospital educational program focused on the LCD for IGT. METHODS: The subjects were 72 patients with IGT (36 in the LCD group and 36 in the control group) who were enrolled from April 2007-March 2012 and followed for 12 months. We retrospectively compared the LCD group with the control group. RESULTS: In 69.4% of the LCD group, blood glucose was normalized at 12 months and the 2-hour plasma glucose level in the oral glucose tolerance test (OGTT) was reduced by 33 mg/dL. In addition, the incidence of diabetes was significantly lower in the LCD group than in the control group at 12 months (0% versus 13.9%, P=0.02). The LCD group showed a significant decrease in fasting plasma glucose, hemoglobin A1c, the homeostasis model of assessment of insulin resistance value, body weight and serum triglycerides (TGs) at 12 months, while there was a significant increase of the serum high-density lipoprotein (HDL) cholesterol level. CONCLUSION: The LCD is effective for normalizing blood glucose and preventing progression to type 2 diabetes in patients with IGT.

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