Abstract 219: NAD Redox Imbalance Accelerates Diabetic Cardiomyopathy via Protein Acetylation and Oxidative Stress

2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Ying Ann Chiao ◽  
Christine Light ◽  
Xiaojian Shi ◽  
Rong Tian ◽  
Junichi Sadoshima ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Mouse Models ◽  
Diabetic Cardiomyopathy ◽  
Cardiac Fibrosis ◽  
Redox Balance ◽  
Protein Acetylation ◽  
Redox Imbalance ◽  
Nadh Ratio ◽  
Systolic And Diastolic Function ◽  
And Oxidative Stress

Diabetes is long linked to lowered NAD/NADH ratio, aka NAD redox imbalance, but its causal role to diabetic cardiomyopathy is not established. We used mouse models with latent decrease in cardiac NAD/NADH ratio (cardiac-specific Ndufs4-KO, cKO) and elevated cardiac NAD levels to directly test whether cardiac NAD redox imbalance accelerates diabetic cardiomyopathy. Control and cKO mice were subjected to 8-week T1D stress, and longitudinal cardiac function was measured by echocardiography. Accelerated declines in systolic and diastolic function were observed in T1D cKO mice. Insulin depletion and hyperglycemia were similar in T1D control and T1D cKO mice, and serum metabolomic analyses showed unchanged aqueous and lipid metabolite levels. These metabolite results suggested that T1D control and cKO hearts were stressed under similar diabetic conditions. Importantly, elevation of cardiac NAD levels to attenuate NAD redox imbalance mitigated the accelerated functional declines in T1D cKO hearts. The data from mouse models with manipulated NAD redox states suggested that NAD redox imbalance accelerates diabetic cardiomyopathy. Cardiac fibrosis levels were not different in T1D control and cKO hearts, while transcript levels of fibrotic genes, including Adamts proteinases, integrins, laminins, matrix metalloproteinases and collagens, also showed no difference. Therefore, the accelerated functional declines in T1D cKO hearts are not due to altered extracellular matrix environment, but are rather due to cardiomyocyte dysfunction. We next determined whether the accelerated cardiac dysfunction is mediated via protein acetylation and oxidative stress. NAD-dependent global protein acetylation and inhibitory acetylation of superoxide dismutase 2 were elevated in T1D cKO hearts. Inhibition of SOD2 concomitantly promoted elevation of protein oxidation levels in T1D cKO hearts. The results suggested that NAD redox balance-dependent protein acetylation regulates oxidative stress to promote diabetic cardiomyopathy.

scholarly journals NAD + Redox Imbalance in the Heart Exacerbates Diabetic Cardiomyopathy

2021 ◽  
Author(s):  
Ying Ann Chiao ◽  
Akash Deep Chakraborty ◽  
Christine M. Light ◽  
Rong Tian ◽  
Junichi Sadoshima ◽  
...  
Keyword(s):  
Mouse Models ◽  
Diabetic Cardiomyopathy ◽  
Cardiac Dysfunction ◽  
Nicotinamide Adenine Dinucleotide ◽  
Redox Balance ◽  
Diabetic Mice ◽  
Redox Imbalance ◽  
Diastolic Velocity ◽  
Nadh Ratio ◽  
Fractional Shortening

Background: Diabetes is a risk factor for heart failure and promotes cardiac dysfunction. Diabetic tissues are associated with nicotinamide adenine dinucleotide (NAD + ) redox imbalance; however, the hypothesis that NAD + redox imbalance causes diabetic cardiomyopathy has not been tested. This investigation used mouse models with altered NAD + redox balance to test this hypothesis. Methods: Diabetic stress was induced in mice by streptozotocin. Cardiac function was measured by echocardiography. Heart and plasma samples were collected for biochemical, histological, and molecular analyses. Two mouse models with altered NAD + redox states (1, Ndufs4 [NADH:ubiquinone oxidoreductase subunit S4] knockout, cKO, and 2, NAMPT [nicotinamide phosphoribosyltranferase] transgenic mice, NMAPT) were used. Results: Diabetic stress caused cardiac dysfunction and lowered NAD + /NADH ratio (oxidized/reduced ratio of nicotinamide adenine dinucleotide) in wild-type mice. Mice with lowered cardiac NAD + /NADH ratio without baseline dysfunction, cKO mice, were challenged with chronic diabetic stress. NAD + redox imbalance in cKO hearts exacerbated systolic (fractional shortening: 27.6% versus 36.9% at 4 weeks, male cohort P <0.05), and diastolic dysfunction (early-to-late ratio of peak diastolic velocity: 0.99 versus 1.20, P <0.05) of diabetic mice in both sexes. Collagen levels and transcripts of fibrosis and extracellular matrix–dependent pathways did not show changes in diabetic cKO hearts, suggesting that the exacerbated cardiac dysfunction was due to cardiomyocyte dysfunction. NAD + redox imbalance promoted superoxide dismutase 2 acetylation, protein oxidation, troponin I S150 phosphorylation, and impaired energetics in diabetic cKO hearts. Importantly, elevation of cardiac NAD + levels by NAMPT normalized NAD + redox balance, alleviated cardiac dysfunction (fractional shortening: 40.2% versus 24.8% in cKO:NAMPT versus cKO, P <0.05; early-to-late ratio of peak diastolic velocity: 1.32 versus 1.04, P <0.05), and reversed pathogenic mechanisms in diabetic mice. Conclusions: Our results show that NAD + redox imbalance to regulate acetylation and phosphorylation is a critical mediator of the progression of diabetic cardiomyopathy and suggest the therapeutic potential for diabetic cardiomyopathy by harnessing NAD + metabolism.

Abstract MP211: NAD Redox Imbalance Exacerbates Diabetic Cardiomyopathy

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Chi Fung Lee
Keyword(s):  
Diastolic Dysfunction ◽  
Diabetic Cardiomyopathy ◽  
Calcium Sensitivity ◽  
Redox Balance ◽  
Diabetic Control ◽  
Redox Imbalance ◽  
Nadh Ratio ◽  
Streptozotocin Induced Diabetes ◽  
Systolic And Diastolic Function ◽  
Myofilament Calcium Sensitivity

Diabetes and heart failure are linked to NAD redox imbalance, whose role in diabetic cardiomyopathy has not been directly tested. Streptozotocin-induced diabetes in WT mice for 16 weeks promoted declines in systolic and diastolic function, which associated with lowered cardiac NAD/NADH ratio (NAD redox imbalance). To test the hypothesis that , we employed mouse models with cardiac-specific manipulations of NAD redox states. Cardiac-specific Ndufs4-KO mice (cKO) exhibit lowered cardiac NAD/NADH ratio with normal baseline function, geometry and energetics. Control and cKO mice were challenged with 8-week diabetic stress. Metabolomic analyses of plasma collected after the diabetic stress showed similar hyperglycemia and dyslipidemia stresses in diabetic control and diabetic cKO mice. Chronic diabetic stress promoted systolic and diastolic dysfunctions in control mice, which were further exacerbated in diabetic cKO mice in both male and female cohorts. Collagen levels and transcript analyses of fibrosis and extracellular matrix-dependent pathways showed no change in diabetic cKO hearts, suggesting that cardiomyocyte dysfunction is a likely culprit for the exacerbated dysfunction. Increased protein acetylation, including SOD2-K68Ac, was observed in diabetic cKO hearts. Inhibited antioxidant function by SOD2-K68Ac promoted protein oxidation in diabetic cKO hearts, suggesting oxidative stress as a pathogenic mechanism. We next examined phosphorylation status of myofilament proteins in these diabetic hearts. MyBPC-S282Pi levels are suppressed in failing hearts and remained unchanged in diabetic cKO hearts. TnI-S150Pi increases myofilament calcium sensitivity and prolongs calcium dissociation, while TnI-S23/24Pi imposes the opposite effects. TnI-S150Pi levels were elevated in diabetic cKO hearts, while TnI-S23/24Pi levels unchanged. Therefore, exacerbated diastolic dysfunction in diabetic cKO hearts is due to the selective phosphorylation at TnI-S150. AMPK is activated by energetic stress and phosphorylates TnI-S150. ATP levels decreased, and AMP/ATP ratio increased in diabetic cKO hearts, implicating impaired energetics to promote TnI-S150Pi and dysfunction. Elevation of NAD levels normalized cardiac NAD redox balance in diabetic cKO hearts. Elevated levels of SOD2-K68Ac and TnI-S150Pi, exacerbated systolic and diastolic dysfunction in diabetic cKO hearts were all reversed by elevation of NAD levels. Dysfunction in diabetic control hearts was also ameliorated by elevation of NAD levels. These data collectively conclude that NAD redox imbalance is a positive mediator of the progression of diabetic cardiomyopathy.

Abstract 17069: NAD+Redox Imbalance in the Heart Exacerbates Diabetic Cardiomyopathy

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Akash Deep D Chakraborty ◽  
Ying Ann Chiao ◽  
Christine M Light ◽  
Rong Tian ◽  
Junichi Sadoshima ◽  
...  
Keyword(s):  
Diabetic Cardiomyopathy ◽  
Cardiac Dysfunction ◽  
Diabetic Control ◽  
Causal Role ◽  
Protein Acetylation ◽  
Specific Expression ◽  
Redox Imbalance ◽  
Nadh Ratio ◽  
Systolic And Diastolic Function

Diabetes is a risk factor of heart failure and leads to cardiac dysfunction, a condition named diabetic cardiomyopathy (DCM). NAD redox imbalance is observed in diabetic tissues. However, whether NAD redox imbalance promotes cardiac dysfunction in DCM remains unknown. The objective of this study is to determine the causal role of NAD redox imbalance in DCM.Type 1 diabetes was induced in C57BL6 mice by streptozotocin (STZ) injections, and DCM was allowed to develop for 16 weeks. Diabetes-induced chronic stress led to systolic and diastolic cardiac dysfunction along with a lowered NAD/NADH ratio. The diabetogenic protocol was applied to control and cardiac-specific Ndufs4-KO mice (cKO), a mouse model with lowered cardiac NAD/NADH without baseline cardiac dysfunction. Analyses of blood glucose and >200 metabolites in plasma showed no significant change in diabetic control and diabetic cKO mice, suggesting that their hearts experienced similar diabetic stress. Diabetic cKO hearts showed lowered NAD/NADH, aggravated contractile and relaxation dysfunction compared to the diabetic control hearts in both sexes. The data suggest that NAD redox imbalance exacerbated DCM. Collagen staining and transcript analyses of fibrosis-related genes showed no change in diabetic cKO hearts, signifying that the exacerbated dysfunction was due to cardiomyocyte dysfunction. A global protein acetylation was promoted in the diabetic cKO hearts with an increase in SOD2 acetylation levels at lysine-68 (SOD2-K68Ac) and enhanced protein oxidation. Diabetic cKO mice displayed enhanced levels of TnI S150 phosphorylation (TnI-S150Pi), but not phosphorylation of TnI-S23/24 or MyBPc-S282. These data suggest that enhanced oxidative stress and altered myofilament Ca 2+ sensitivity via TnI-S150Pi are responsible for the NAD redox imbalance-exacerbated DCM.To confirm the role of NAD redox imbalance in DCM, we elevated cardiac NAD levels in diabetic cKO mice by cardiac-specific expression of NAMPT. Expression of NAMPT in the heart improved cardiac systolic and diastolic function in diabetic cKO hearts. This was due to increased NAD/NADH ratio and reversed pathogenic mechanisms (lowered SOD2-K68Ac and TnI-S150Pi). This study supports the causal role of NAD redox imbalance in DCM.

scholarly journals NAD+ Redox Imbalance in the Heart Exacerbates Diabetic Cardiomyopathy

2020 ◽  
Author(s):  
Ying Ann Chiao ◽  
Akash Deep Chakraborty ◽  
Christine M. Light ◽  
Rong Tian ◽  
Junichi Sadoshima ◽  
...  
Keyword(s):  
Diabetic Cardiomyopathy ◽  
Cardiac Dysfunction ◽  
Troponin I ◽  
Therapeutic Potential ◽  
Redox Balance ◽  
Diabetic Mice ◽  
Nicotinamide Phosphoribosyltransferase ◽  
Redox Imbalance ◽  
Nadh Ratio ◽  
Regulate Protein

AbstractBackgroundDiabetes is a risk factor of heart failure and promotes cardiac dysfunction. Diabetic tissues are associated with NAD+ redox imbalance; however, the hypothesis that NAD+ redox imbalance leads to dysfunction of diabetic hearts has not been tested. In this study, we employed mouse models with altered NAD+ redox balance to test the hypothesis.Methods and ResultsDiabetes was induced in C57BL/6 mice by streptozotocin injections, and diabetic cardiomyopathy (DCM) was allowed to develop for 16 weeks. Diabetic stress led to cardiac dysfunction and lowered NAD+/NADH ratio. This diabetogenic regimen was administered to cardiac-specific knockout mice of complex I subunit Ndufs4 (cKO), a model with lowered cardiac NAD+/NADH ratio without baseline dysfunction. Cardiac NAD+ redox imbalance in cKO hearts exacerbated systolic and diastolic dysfunction of diabetic mice in both sexes. Collagen levels and transcript analyses of fibrosis and extracellular matrix-dependent pathways did not show change in diabetic cKO hearts, suggesting that the exacerbated cardiac dysfunction was likely due to cardiomyocyte dysfunction. We found that cardiac NAD+ redox imbalance promoted superoxide dismutase 2 (SOD2) acetylation, protein oxidation, induced troponin I S150 phosphorylation and impaired energetics in diabetic cKO hearts. Importantly, elevation of cardiac NAD+ levels by nicotinamide phosphoribosyltransferase (NAMPT) normalized NAD+ redox balance, over-expression alleviated cardiac dysfunction and reversed pathogenic mechanisms in diabetic mice.ConclusionOur results show that NAD+ redox imbalance to regulate protein acetylation and phosphorylation is a critical mediator of the progression of DCM, and suggest the therapeutic potential of harnessing NAD+ metabolism in DCM.

scholarly journals Deletion of RasGRF1 Attenuated Interstitial Fibrosis in Streptozotocin-Induced Diabetic Cardiomyopathy in Mice through Affecting Inflammation and Oxidative Stress

2018 ◽  
Vol 19 (10) ◽  
pp. 3094 ◽  
Author(s):  
Tzu-Hsien Tsai ◽  
Cheng-Jei Lin ◽  
Sarah Chua ◽  
Sheng-Ying Chung ◽  
Shyh-Ming Chen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Diastolic Function ◽  
Diabetic Cardiomyopathy ◽  
Cardiac Fibrosis ◽  
Interstitial Fibrosis ◽  
Cardiac Inflammation ◽  
Matrix Deposition ◽  
Stress Markers ◽  
Group 2 ◽  
And Oxidative Stress

Background: Diabetic cardiomyopathy (DCM) is characterized by cardiac fibrosis and stiffness, which often develops into heart failure. This study investigated the role of Ras protein-specific guanine nucleotide releasing factor 1 (RasGRF1) in the development of DCM. Methods: Forty-eight mice were divided into four groups (n = 12 per group): Group 1: Wild-type (WT) mice, Group 2: RasGRF1 deficiency (RasGRF1−/−) mice. Group 3: Streptozotocin (STZ)-induced diabetic WT mice, Group 4: STZ-induced diabetic RasGRF1−/− mice. Myocardial functions were assessed by cardiac echography. Heart tissues from all of the mice were investigated for cardiac fibrosis, inflammation, and oxidative stress markers. Results: Worse impaired diastolic function with elevation serum interleukin (IL)-6 was found in the diabetic group compared with the non-diabetic groups. Serum IL-6 levels were found to be elevated in the diabetic compared with the non-diabetic groups. However, the diabetic RasGRF1−/− mice exhibited lower serum IL-6 levels and better diastolic function than the diabetic WT mice. The diabetic RasGRF1−/− mice were associated with reduced cardiac inflammation, which was shown by lower invading inflammation cells, lower expression of matrix metalloproteinase 9, and less chemokines compared to the diabetic WT mice. Furthermore, less oxidative stress as well as extracellular matrix deposition leading to a reduction in cardiac fibrosis was also found in the diabetic RasGRF1−/− mice compared with the diabetic WT mice. Conclusion: The deletion of RasGRF1 attenuated myocardial fibrosis and improved cardiac function in diabetic mice through inhibiting inflammation and oxidative stress.

scholarly journals Imaging of redox-imbalance and oxidative stress in kidney in vivo, induced by dietary cholesterol

2019 ◽  
Vol 33 (1) ◽  
pp. 294-301
Author(s):  
Dessislava Lazarova ◽  
Sayaka Shibata ◽  
Itsuko Ishii ◽  
Genoveva Zlateva ◽  
Zhivko Zhelev ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Dietary Cholesterol ◽  
Redox Imbalance ◽  
And Oxidative Stress
Sign in / Sign up

Export Citation Format

Share Document