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J Am Heart Assoc. 2016 May 5;5(5). pii: e003046. doi: 10.1161/JAHA.115.003046.

Role of Mitochondrial Oxidative Stress in Glucose Tolerance, Insulin Resistance, and Cardiac Diastolic Dysfunction.

Author information

1
Cardiovascular Research Center, Lifespan Rhode Island Hospital, Providence, RI The Warren Alpert Medical School, Brown University, Providence, RI Providence Veterans Affairs Medical Center, Providence, RI.
2
Section of Cardiology, University of Illinois at Chicago, IL.
3
Cardiovascular Research Center, Lifespan Rhode Island Hospital, Providence, RI.
4
The Warren Alpert Medical School, Brown University, Providence, RI.
5
Center for Cardiovascular Research, University of Illinois at Chicago, IL Department of Physiology and Biophysics, University of Illinois at Chicago, IL.
6
Cardiovascular Research Center, Lifespan Rhode Island Hospital, Providence, RI The Warren Alpert Medical School, Brown University, Providence, RI Providence Veterans Affairs Medical Center, Providence, RI samuel_dudley@brown.edu.

Abstract

BACKGROUND:

Diabetes mellitus (DM) is associated with mitochondrial oxidative stress. We have shown that myocardial oxidative stress leads to diastolic dysfunction in a hypertensive mouse model. Therefore, we hypothesized that diabetes mellitus could cause diastolic dysfunction through mitochondrial oxidative stress and that a mitochondria-targeted antioxidant (MitoTEMPO) could prevent diastolic dysfunction in a diabetic mouse model.

METHODS AND RESULTS:

C57BL/6J mice were fed either 60 kcal % fat diet (high-fat diet [HFD]) or normal chow (control) for 8 weeks with or without concurrent MitoTEMPO administration, followed by in vivo assessment of diastolic function and ex vivo studies. HFD mice developed impaired glucose tolerance compared with the control (serum glucose=495±45 mg/dL versus 236±30 mg/dL at 60 minutes after intraperitoneal glucose injection, P<0.05). Myocardial tagged cardiac magnetic resonance imaging showed significantly reduced diastolic circumferential strain (Ecc) rate in the HFD mice compared with controls (5.0±0.3 1/s versus 7.4±0.5 1/s, P<0.05), indicating diastolic dysfunction in the HFD mice. Systolic function was comparable in both groups (left ventricular ejection fraction=66.4±1.4% versus 66.7±1.2%, P>0.05). MitoTEMPO-treated HFD mice showed significant reduction in mitochondria reactive oxygen species, S-glutathionylation of cardiac myosin binding protein C, and diastolic dysfunction, comparable to the control. The fasting insulin levels of MitoTEMPO-treated HFD mice were also comparable to the controls (P>0.05).

CONCLUSIONS:

MitoTEMPO treatment prevented insulin resistance and diastolic dysfunction, suggesting that mitochondrial oxidative stress may be involved in the pathophysiology of both conditions.

KEYWORDS:

diastolic dysfunction; insulin resistance; mitochondrial oxidative stress

PMID:
27151515
PMCID:
PMC4889180
DOI:
10.1161/JAHA.115.003046
[Indexed for MEDLINE]
Free PMC Article

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