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Maintaining Myocardial Glucose Utilization in Diabetic Cardiomyopathy Accelerates Mitochondrial Dysfunction
Journal article   Open access   Peer reviewed

Maintaining Myocardial Glucose Utilization in Diabetic Cardiomyopathy Accelerates Mitochondrial Dysfunction

Adam R Wende, John C Schell, Chae-Myeong Ha, Mark E Pepin, Oleh Khalimonchuk, Hansjörg Schwertz, Renata O Pereira, Manoja K Brahma, Joseph Tuinei, Ariel Contreras-Ferrat, …
Diabetes (New York, N.Y.), Vol.69(10), pp.2094-2111
10/2020
DOI: 10.2337/db19-1057
PMCID: PMC7506832
PMID: 32366681
url
https://europepmc.org/articles/pmc7506832View
Published (Version of record) Open Access

Abstract

Cardiac glucose uptake and oxidation are reduced in diabetes despite hyperglycemia. Mitochondrial dysfunction contributes to heart failure in diabetes. It is unclear whether these changes are adaptive or maladaptive. To directly evaluate the relationship between glucose delivery and mitochondrial dysfunction in diabetic cardiomyopathy, we generated transgenic mice with inducible cardiomyocyte-specific expression of the GLUT4. We examined mice rendered hyperglycemic following low-dose streptozotocin prior to increasing cardiomyocyte glucose uptake by transgene induction. Enhanced myocardial glucose in nondiabetic mice decreased mitochondrial ATP generation and was associated with echocardiographic evidence of diastolic dysfunction. Increasing myocardial glucose delivery after short-term diabetes onset exacerbated mitochondrial oxidative dysfunction. Transcriptomic analysis revealed that the largest changes, driven by glucose and diabetes, were in genes involved in mitochondrial function. This glucose-dependent transcriptional repression was in part mediated by\n-GlcNAcylation of the transcription factor Sp1. Increased glucose uptake induced direct\n-GlcNAcylation of many electron transport chain subunits and other mitochondrial proteins. These findings identify mitochondria as a major target of glucotoxicity. They also suggest that reduced glucose utilization in diabetic cardiomyopathy might defend against glucotoxicity and caution that restoring glucose delivery to the heart in the context of diabetes could accelerate mitochondrial dysfunction by disrupting protective metabolic adaptations.
Diabetic Cardiomyopathies - genetics Mitochondria Animals Fatty Acids Myocardium Mice Glucose Diabetes Mellitus

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