• Open Access

Advanced glycation endproduct (AGE) accumulation and AGE receptor (RAGE) up-regulation contribute to the onset of diabetic cardiomyopathy

Authors

  • Heng Ma,

    1. Department of Physiology, Fourth Military Medical University, Xi’an, China
    2. Division of Pharmaceutical Sciences & Center for Cardiovascular Research and Alternative Medicine, University of Wyoming, Laramie, WY, USA
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    • Equal first authorship.

  • Shi-Yan Li,

    1. Division of Pharmaceutical Sciences & Center for Cardiovascular Research and Alternative Medicine, University of Wyoming, Laramie, WY, USA
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    • Equal first authorship.

  • Peisheng Xu,

    1. Division of Pharmaceutical Sciences & Center for Cardiovascular Research and Alternative Medicine, University of Wyoming, Laramie, WY, USA
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  • Sara A. Babcock,

    1. Division of Pharmaceutical Sciences & Center for Cardiovascular Research and Alternative Medicine, University of Wyoming, Laramie, WY, USA
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  • E. Kurt Dolence,

    1. Division of Pharmaceutical Sciences & Center for Cardiovascular Research and Alternative Medicine, University of Wyoming, Laramie, WY, USA
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  • Michael Brownlee,

    1. Diabetes Research Center, Albert Einstein College of Medicine, New York, NY, USA
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  • Ji Li,

    1. Division of Pharmaceutical Sciences & Center for Cardiovascular Research and Alternative Medicine, University of Wyoming, Laramie, WY, USA
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  • Jun Ren

    Corresponding author
    1. Department of Physiology, Fourth Military Medical University, Xi’an, China
    2. Division of Pharmaceutical Sciences & Center for Cardiovascular Research and Alternative Medicine, University of Wyoming, Laramie, WY, USA
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Correspondence to: Dr. Jun REN, Center for Cardiovascular Research and Alternative Medicine, University of Wyoming, Laramie, WY 82071, USA.
Tel.: (307) 766-6131
Fax: (307) 766-2953
E-mail: jren@uwyo.edu

Abstract

Diabetic cardiomyopathy is manifested by compromised systolic and diastolic function. This study was designed to examine the role of advanced glycation endproduct (AGE) and AGE receptor (RAGE) in diabetic cardiomyopathy. Heart function was assessed in isolated control and streptozotocin-induced diabetic hearts following in vivo RAGE gene knockdown using RNA interference. Cardiomyocyte mechanical properties were evaluated including peak shortening (PS), time-to-PS (TPS) and time-to-90% relengthening (TR90). RAGE was assayed by RT-PCR and immunoblot. Diabetes significantly enhanced cardiac MG, AGE and RAGE levels accompanied with colocalization of AGE and RAGE in cardiomyocytes. Diabetes-elicited increase in RAGE was inhibited by in vivo siRNA interference. The AGE formation inhibitor benfotiamine significantly attenuated diabetes-induced elevation in MG, AGE, RAGE and collagen cross-linking without affecting hypertriglyceridaemia and hypercholesterolaemia in diabetes. Diabetes markedly decreased LV contractility, as evidenced by reduced ±dP/dt and LV developed pressure (LVDP), which were protected by RAGE gene knockdown. In addition, MG-derived AGE (MG-AGE) up-regulated cardiac RAGE mRNA and triggered cardiomyocyte contractile dysfunction reminiscent of diabetic cardiomyopathy. The MG-AGE-elicited prolongation of TPS and TR90 was ablated by an anti-RAGE antibody in cardiomyocytes. Interestingly, MG-AGE-induced cardiomyocyte dysfunction was associated with mitochondrial membrane potential (MMP) depolarization and reduced GSK-3β inactivation in control cardiomyocytes, similar to those from in vivo diabetes. Treatment with siRNA-RAGE ablated diabetes-induced MMP depolarization and GSK-3β inactivation. Collectively, our result implicated a role of AGE-RAGE in the pathogenesis of diabetic cardiomyopathy.

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