scholarly journals Cardiac Expression of Human Type 2 Iodothyronine Deiodinase Increases Glucose Metabolism and Protects Against Doxorubicin-induced Cardiac Dysfunction in Male Mice

Endocrinology ◽  
2013 ◽  
Vol 154 (10) ◽  
pp. 3937-3946 ◽  
Author(s):  
Eun-Gyoung Hong ◽  
Brian W. Kim ◽  
Dae Young Jung ◽  
Jong Hun Kim ◽  
Tim Yu ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Cardiac Function ◽  
Cardiac Dysfunction ◽  
Cardiac Metabolism ◽  
Metabolic Effects ◽  
Iodothyronine Deiodinase ◽  
Myocardial Glucose Metabolism ◽  
Human Type

Altered glucose metabolism in the heart is an important characteristic of cardiovascular and metabolic disease. Because thyroid hormones have major effects on peripheral metabolism, we examined the metabolic effects of heart-selective increase in T3 using transgenic mice expressing human type 2 iodothyronine deiodinase (D2) under the control of the α-myosin heavy chain promoter (MHC-D2). Hyperinsulinemic-euglycemic clamps showed normal whole-body glucose disposal but increased hepatic insulin action in MHC-D2 mice as compared to wild-type (WT) littermates. Insulin-stimulated glucose uptake in heart was not altered, but basal myocardial glucose metabolism was increased by more than two-fold in MHC-D2 mice. Myocardial lipid levels were also elevated in MHC-D2 mice, suggesting an overall up-regulation of cardiac metabolism in these mice. The effects of doxorubicin (DOX) treatment on cardiac function and structure were examined using M-mode echocardiography. DOX treatment caused a significant reduction in ventricular fractional shortening and resulted in more than 50% death in WT mice. In contrast, MHC-D2 mice showed increased survival rate after DOX treatment, and this was associated with a six-fold increase in myocardial glucose metabolism and improved cardiac function. Myocardial activity and expression of AMPK, GLUT1, and Akt were also elevated in MHC-D2 and WT mice following DOX treatment. Thus, our findings indicate an important role of thyroid hormone in cardiac metabolism and further suggest a protective role of glucose utilization in DOX-mediated cardiac dysfunction.

Abstract 1209: Interleukin-6 Reduces Myocardial Glucose Metabolism by Altering AMPK, Insulin Signaling, and PKC-𝛉 in Mice

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Zhiyou Zhang ◽  
Hwi Jin Ko ◽  
Dae Young Jung ◽  
Zhexi Ma ◽  
Jason K Kim
Keyword(s):  
Glucose Metabolism ◽  
Insulin Signaling ◽  
Insulin Action ◽  
Cardiac Metabolism ◽  
Negative Regulator ◽  
Saline Control ◽  
Myocardial Glucose Metabolism ◽  
Peripheral Organs

Increasing evidence implicates the role of inflammation in the pathogenesis of diabetes and complications. Inflammatory cytokines (IL-6, TNF-α) are elevated in obese diabetic subjects, and are shown to modulate glucose metabolism in peripheral organs. In this report, we examined the effects of IL-6 on cardiac metabolism and insulin action in vivo. Male C57BL/6 mice were intravenously treated with IL-6 (16 ng/hr) or saline (control) for 2 hrs, and [ 14 C]2-deoxyglucose was intravenously injected in awake mice to measure myocardial glucose metabolism (n=9~10). Hyperinsulinemic-euglycemic clamps (2.5 mU/kg/min insulin infusion) were also performed in IL-6 or saline-treated mice (n=4~5) to measure cardiac insulin action. Acute treatment with IL-6 caused a 25% increase in myocardial STAT3 activity and significantly reduced basal myocardial glucose metabolism (Fig. 1 ; * P< 0.05). IL-6 treatment also reduced insulin-stimulated glucose uptake in heart, and these effects were associated with marked decreases in AMPK activity (Thr-phosphorylation of AMPK; Fig. 2 ) and IRS-1 tyrosine phosphorylation (Fig. 3 ). Acute IL-6 treatment increased myocardial expression of PKC-𝛉, which has been shown to mediate insulin resistance in peripheral organs (Fig. 4 ). These results indicate that IL-6 is a potent negative regulator of myocardial glucose metabolism and insulin action, and the underlying mechanism may involve IL-6 mediated activation of PKC-𝛉 and defects in AMPK and insulin signaling activity. Thus, our findings suggest a potential role of IL-6 in the pathogenesis of diabetic heart failure.

scholarly journals Molecular Mechanisms of Obesity-Linked Cardiac Dysfunction: An Up-Date on Current Knowledge

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 629
Author(s):  
Jorge Gutiérrez-Cuevas ◽  
Ana Sandoval-Rodriguez ◽  
Alejandra Meza-Rios ◽  
Hugo Christian Monroy-Ramírez ◽  
Marina Galicia-Moreno ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cardiac Dysfunction ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Peroxisome Proliferator ◽  
White Adipocyte ◽  
Peroxisome Proliferator Activated Receptors ◽  
And Oxidative Stress

Obesity is defined as excessive body fat accumulation, and worldwide obesity has nearly tripled since 1975. Excess of free fatty acids (FFAs) and triglycerides in obese individuals promote ectopic lipid accumulation in the liver, skeletal muscle tissue, and heart, among others, inducing insulin resistance, hypertension, metabolic syndrome, type 2 diabetes (T2D), atherosclerosis, and cardiovascular disease (CVD). These diseases are promoted by visceral white adipocyte tissue (WAT) dysfunction through an increase in pro-inflammatory adipokines, oxidative stress, activation of the renin-angiotensin-aldosterone system (RAAS), and adverse changes in the gut microbiome. In the heart, obesity and T2D induce changes in substrate utilization, tissue metabolism, oxidative stress, and inflammation, leading to myocardial fibrosis and ultimately cardiac dysfunction. Peroxisome proliferator-activated receptors (PPARs) are involved in the regulation of carbohydrate and lipid metabolism, also improve insulin sensitivity, triglyceride levels, inflammation, and oxidative stress. The purpose of this review is to provide an update on the molecular mechanisms involved in obesity-linked CVD pathophysiology, considering pro-inflammatory cytokines, adipokines, and hormones, as well as the role of oxidative stress, inflammation, and PPARs. In addition, cell lines and animal models, biomarkers, gut microbiota dysbiosis, epigenetic modifications, and current therapeutic treatments in CVD associated with obesity are outlined in this paper.

Abstract 87: Loss of Mir-155 Attenuates Sepsis Induced Cardiac Dysfunction

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Hui Wang ◽  
Yihua Bei ◽  
Jing Shi ◽  
Wei Sun ◽  
Peipei Huang ◽  
...  
Keyword(s):  
Cardiac Dysfunction ◽  
Foam Cell ◽  
Cardiac Metabolism ◽  
Significant Inhibition ◽  
Gene Expressions ◽  
Over Expression ◽  
Pathological Cardiac Hypertrophy ◽  
Lps Treatment ◽  
Fractional Shortening

Objective: Sepsis induced cardiac dysfunction is featured by inflammation and metabolic repression. miR-155 is a typical multifunctional miRNA and loss of miR-155 has been shown to protect the heart from pathological cardiac hypertrophy while increased miR-155 could promote the formation of foam cell in atherogenesis. However, the role of miR-155 in sepsis induced cardiac dysfunction is unclear. Methods: E.coli lipopolysaccharide (LPS) (5mg/kg) was administered to C57BL/6 mice to create a sepsis-induced cardiac dysfunction model. Cardiac function was assessed by echocardiography 5-6 h post-LPS administration. Heart tissues were collected within 7-9 h after LPS treatment for the analysis of gene expressions. Tail vein injection of miR-155 antagomir (80mg/kg/d) or miR-155 agomirs (30mg/kg/d) for 3 consecutive days were used to decrease or increase miR-155 expressions in heart. Results: LPS induced a reduction of 15% in fractional shortening (%FS) and 25% in ejection fraction (%EF). Expression of miR-155 was increased by 2 fold in sepsis-induced cardiac dysfunction mouse model. Over-expression of miR-155 agomirs led to a decrease of 5% in FS and 10% in EF as compared to scramble controls. Aggravation of LPS induced cardiac dysfunction by miR-155 agomir was not associated with alteration in inflammation or cardiac metabolism. However, miR-155 agomir increased LPS- induced myocardium apoptosis and also elevated the ratio of Bax/Bcl-2 at the protein level. Intravenous injection of cholesterol-modified antisense oligonucleorides antagomirs of miR-155 markedly rescued the LPS induced heart failure and apoptosis. Western bloting indicated that miR-155 overexpression in vivo led to a significant inhibition of Pea15a while miR-155 knock-down caused a significant upregulation of Pea15a, indicating that Pea15a was a potential target gene of miR-155. Interestingly, plasma miR-155 levels were also found to be significantly increased in critically ill patients with sepsis compared to healthy controls. Conclusion: This study demonstrates that miR-155 regulates sepsis induced cardiac dysfunction and Pea15a is a potential targer gene of miR-155. Loss of miR-155 represents a novel therapeutic method for sepsis induced cardiac dysfunction

Abstract 1766: Diet-Induced Obesity Causes Inflammation by Activating Toll-Like Receptor 4 Signaling and Downregulates AMPK in Heart

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Hwi Jin Ko ◽  
Dae Young Jung ◽  
Zhexi Ma ◽  
Jason K Kim
Keyword(s):  
Glucose Metabolism ◽  
Whole Body ◽  
Chow Diet ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Myocardial Glucose Metabolism ◽  
Cardiac Inflammation ◽  
Protein Levels ◽  
Diet Induced Obesity

Increasing evidence implicates the role of inflammation in diabetes and complications. Macrophages are shown to infiltrate adipose tissue in obesity, and inflammatory cytokines alter glucose metabolism in peripheral organs. Male C57BL/6 mice were fed high-fat diet (HFD; 55% fat by calories) or chow diet for 6 weeks, and heart samples were taken for analysis (n = 5~7). Chronic HFD increased whole body fat mass, measured by 1 H-MRS, by 3-fold, and elevated plasma IL-6 and TNF-α levels by 40%. Diet-induced obesity caused inflammation in heart and increased macrophage-specific CD68 levels by 5-fold (Fig. 1) (* P < 0.05 vs Chow). Diet-induced cardiac inflammation was associated with significant increases in toll-like receptor 4 (TLR4) and MyD88 levels in heart (Fig. 2). HFD also increased cardiomyocyte SOCS3 levels by more than 3-fold (Fig. 3). Myocardial glucose metabolism was measured using intravenous injection of 2-[ 14 C]deoxyglucose in awake mice (n = 6). Chronic HFD reduced myocardial glucose uptake by 50%, and this was associated with significant reductions in total GLUT4 and GLUT1 protein levels. Further, Thr 172 phosphorylation of AMPK, a critical regulator of energy balance, was markedly reduced in heart following HFD (Fig. 4). These results demonstrate that diet-induced obesity causes macrophage infiltration and inflammation in heart by increasing TLR4 signaling in cardiomyocytes. Similar to the effects of inflammation on peripheral glucose metabolism, diet-induced cardiac inflammation reduced myocardial glucose metabolism by downregulating AMPK and GLUT protein levels. Thus, our findings underscore an important role of inflammation in diabetic heart.

scholarly journals Deletion of Cardiomyocyte Glycogen Synthase Kinase-3 Beta (GSK-3β) Improves Systemic Glucose Tolerance with Maintained Heart Function in Established Obesity

Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1120 ◽  
Author(s):  
Manisha Gupte ◽  
Prachi Umbarkar ◽  
Anand Prakash Singh ◽  
Qinkun Zhang ◽  
Sultan Tousif ◽  
...  
Keyword(s):  
Glucose Tolerance ◽  
Cardiac Function ◽  
Cardiac Dysfunction ◽  
Glycogen Synthase ◽  
Critical Role ◽  
Glycogen Synthase Kinase ◽  
Glycogen Synthase Kinase 3 ◽  
Total Period ◽  
Gsk 3Β

Obesity is an independent risk factor for cardiovascular diseases (CVD), including heart failure. Thus, there is an urgent need to understand the molecular mechanism of obesity-associated cardiac dysfunction. We recently reported the critical role of cardiomyocyte (CM) Glycogen Synthase Kinase-3 beta (GSK-3β) in cardiac dysfunction associated with a developing obesity model (deletion of CM-GSK-3β prior to obesity). In the present study, we investigated the role of CM-GSK-3β in a clinically more relevant model of established obesity (deletion of CM-GSK-3β after established obesity). CM-GSK-3β knockout (GSK-3βfl/flCre+/−) and controls (GSK-3βfl/flCre−/−) mice were subjected to a high-fat diet (HFD) in order to establish obesity. After 12 weeks of HFD treatment, all mice received tamoxifen injections for five consecutive days to delete GSK-3β specifically in CMs and continued on the HFD for a total period of 55 weeks. To our complete surprise, CM-GSK-3β knockout (KO) animals exhibited a globally improved glucose tolerance and maintained normal cardiac function. Mechanistically, in stark contrast to the developing obesity model, deleting CM-GSK-3β in obese animals did not adversely affect the GSK-3αS21 phosphorylation (activity) and maintained canonical β-catenin degradation pathway and cardiac function. As several GSK-3 inhibitors are in the trial to treat various chronic conditions, including metabolic diseases, these findings have important clinical implications. Specifically, our results provide critical pre-clinical data regarding the safety of GSK-3 inhibition in obese patients.

scholarly journals Cardiac Function in Uncomplicated Type 2 Diabetes Mellitus

2019 ◽  
Vol 18 (2) ◽  
pp. 211-215
Author(s):  
Bimal K Agrawal ◽  
Parul Jain ◽  
Saurabh Marwaha ◽  
Richa Goel ◽  
Himanshu D Kumar ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Cardiac Function ◽  
Cardiac Dysfunction ◽  
Left Ventricular ◽  
Diabetic Patients ◽  
Coronary Arterial Disease ◽  
Type 2 Dm

Objective: Diabetic cardiomyopathy (DC) is a myocardial disease characterized by myocyte hypertrophy, interstitial fibrosis, protein glycosylation and intra-myocardial micro-angiopathy due to prolonged exposure of myocardial tissues to hyperglycemia in diabetes mellitus (DM) patients. Alteration in cardiac function can be non-invasively assessed via echocardiography. The early recognition of cardiac dysfunction can prevent the symptomatic heart failure in DM patients. The study aimed at evaluating cardiac function in uncomplicated type 2 diabetes mellitus. Materials And Methods: Sixty Type 2 DM patients without any feature of the coronary arterial disease (CAD), hypertension, nephropathy and respiratory illness were enrolled in the study and compared with the sixty age matched healthy controls. Echocardiographic assessment was done in all subjects to evaluate the cardiac function. Results: Diastolic dysfunction was more common in diabetic patients when compared with normal healthy population. Systolic dysfunction progresses with age of the diabetic patient. Conclusion: Echocardiography is a simple noninvasive cost effective test for detecting cardiac dysfunction in Type 2 DM patients and should be applied to detect early Left ventricular(LV) dysfunction so that corrective measures may be initiated early and cardiac functions may be preserved for long. Bangladesh Journal of Medical Science Vol.18(2) 2019 p.211-215

scholarly journals The role of G protein-coupled receptor kinase 4 in cardiomyocyte injury after myocardial infarction

2020 ◽  
Author(s):  
Liangpeng Li ◽  
Wenbin Fu ◽  
Xue Gong ◽  
Zhi Chen ◽  
Luxun Tang ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Transgenic Mice ◽  
Cardiac Function ◽  
G Protein ◽  
Knockout Mice ◽  
Cardiac Dysfunction ◽  
Beclin 1 ◽  
Receptor Kinase ◽  
G Protein Coupled

Abstract Aims G protein-coupled receptor kinase 4 (GRK4) has been reported to play an important role in hypertension, but little is known about its role in cardiomyocytes and myocardial infarction (MI). The goal of present study is to explore the role of GRK4 in the pathogenesis and progression of MI. Methods and results We studied the expression and distribution pattern of GRK4 in mouse heart after MI. GRK4 A486V transgenic mice, inducible cardiomyocyte-specific GRK4 knockout mice, were generated and subjected to MI with their control mice. Cardiac infarction, cardiac function, cardiomyocyte apoptosis, autophagic activity, and HDAC4 phosphorylation were assessed. The mRNA and protein levels of GRK4 in the heart were increased after MI. Transgenic mice with the overexpression of human GRK4 wild type (WT) or human GRK4 A486V variant had increased cardiac infarction, exaggerated cardiac dysfunction and remodelling. In contrast, the MI-induced cardiac dysfunction and remodelling were ameliorated in cardiomyocyte-specific GRK4 knockout mice. GRK4 overexpression in cardiomyocytes aggravated apoptosis, repressed autophagy, and decreased beclin-1 expression, which were partially rescued by the autophagy agonist rapamycin. MI also induced the nuclear translocation of GRK4, which inhibited autophagy by increasing HDAC4 phosphorylation and decreasing its binding to the beclin-1 promoter. HDAC4 S632A mutation partially restored the GRK4-induced inhibition of autophagy. MI caused greater impairment of cardiac function in patients carrying the GRK4 A486V variant than in WT carriers. Conclusion GRK4 increases cardiomyocyte injury during MI by inhibiting autophagy and promoting cardiomyocyte apoptosis. These effects are mediated by the phosphorylation of HDAC4 and a decrease in beclin-1 expression.

Glucose and Insulin Metabolism in Twins: Influence of Zygosity and Birth Weight

Twin Research ◽  
2001 ◽  
Vol 4 (5) ◽  
pp. 350-355 ◽  
Author(s):  
Pernille Poulsen ◽  
Allan Vaag
Keyword(s):  
Type 2 Diabetes ◽  
Glucose Intolerance ◽  
Twin Studies ◽  
Metabolic Effects ◽  
Diabetes Research ◽  
Relative Role ◽  
Intrauterine Environment ◽  
Dizygotic Twins

AbstractSeveral epidemiological and metabolic studies have demonstrated an impact of the intrauterine environment on the development of disease in adult life, including Type 2 diabetes and glucose intolerance. Our finding of lower birth weights among monozygotic diabetic twins compared to their non-diabetic genetically identical co-twins confirms this association and, furthermore, eliminates the possibility that the association could be explained solely by common genes leading to both impaired intrauterine growth and increased risk of Type 2 diabetes. Due to an often shared placenta monozygotic twins may experience a more adverse intrauterine environment compared to dizygotic twins and may therefore be more prone to develop various metabolic abnormalities. Our findings of a higher glucose and insulin profile after oral glucose ingestion, and recently lower insulin-stimulated glucose uptake — indicating glucose intolerance and insulin resistance — among monozygotic compared to dizygotic twins may to some extent question the validity of classical twin studies in diabetes research where equal environmental influences in monozygotic and dizygotic twins is assumed. The potential role of an adverse intrauterine environment in causing Type 2 diabetes in humans, may to some degree alter our conception of the twin model in diabetes research including the interpretation of aetiological conclusions reached in previous classical twin studies of diabetes. However, our present knowledge is far too insufficient to discard the results from classical twin studies concerning the relative role of genes versus environment for the development of diabetes and its metabolic effects.

Isoflurane Alters Energy Substrate Metabolism to Preserve Mechanical Function in Isolated Rat Hearts following Prolonged No-Flow Hypothermic Storage

2003 ◽  
Vol 98 (2) ◽  
pp. 379-386 ◽  
Author(s):  
Barry A. Finegan ◽  
Manoj Gandhi ◽  
Matthew R. Cohen ◽  
Donald Legatt ◽  
Alexander S. Clanachan
Keyword(s):  
Enhanced Recovery ◽  
Metabolic Effects ◽  
Mechanical Function ◽  
Cardioplegic Arrest ◽  
Channel Activation ◽  
Energy Substrate ◽  
Myocardial Glucose Metabolism ◽  
Substrate Metabolism ◽  
Rat Hearts

Background Isoflurane enhances mechanical function in hearts subject to normothermic global or regional ischemia. The authors examined the effectiveness of isoflurane in preserving mechanical function in hearts subjected to cardioplegic arrest and prolonged hypothermic no-flow storage. The role of isoflurane in altering myocardial glucose metabolism during storage and reperfusion during these conditions and the contribution of adenosine triphosphate-sensitive potassium (K(atp)) channel activation in mediating the functional and metabolic effects of isoflurane preconditioning was determined. Methods Isolated working rat hearts were subjected to cardioplegic arrest with St. Thomas' II solution, hypothermic no-flow storage for 8 h, and subsequent aerobic reperfusion. The consequences of isoflurane treatment were assessed during the following conditions: (1) isoflurane exposure before and during storage; (2) brief isoflurane exposure during early nonworking poststorage reperfusion; and (3) isoflurane preconditioning before storage. The selective mitochondrial and sarcolemmal K(atp) channel antagonists, 5-hydroxydecanoate and HMR 1098, respectively, were used to assess the role of K(atp) channel activation on glycogen consumption during storage in isoflurane-preconditioned hearts. Results Isoflurane enhanced recovery of mechanical function if present before and during storage. Isoflurane preconditioning was also protective. Isoflurane reduced glycogen consumption during storage under the aforementioned circumstances. Storage of isoflurane-preconditioned hearts in the presence of 5-hydroxydecanoate prevented the reduction in glycogen consumption during storage and abolished the beneficial effect of isoflurane preconditioning on recovery of mechanical function. Conclusions Isoflurane provides additive protection of hearts subject to cardioplegic arrest and prolonged hypothermic no-flow storage and favorably alters energy substrate metabolism by modulating glycolysis during ischemia. The effects of isoflurane preconditioning on glycolysis during hypothermic no-flow storage appears to be associated with activation of mitochondrial K(atp) channels.

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