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Genetic manipulation of cardiac Hsp72 levels does not alter substrate metabolism but reveals insights into high-fat feeding-induced cardiac insulin resistance
journal contribution
posted on 2023-05-20, 04:45 authored by Darren HenstridgeDarren Henstridge, Estevez, E, Allen, TL, Heywood, SE, Gardner, T, Yang, C, Mellett, NA, Kingwell, BA, Meikle, PJ, Febbraio, MAHeat shock protein 72 (Hsp72) protects cells against a variety of stressors, and multiple studies have suggested that Hsp72 plays a cardioprotective role. As skeletal muscle Hsp72 overexpression can protect against high-fat diet (HFD)-induced insulin resistance, alterations in substrate metabolism may be a mechanism by which Hsp72 is cardioprotective. We investigated the impact of transgenically overexpressing (Hsp72 Tg) or deleting Hsp72 (Hsp72 KO) on various aspects of cardiac metabolism. Mice were fed a normal chow (NC) or HFD for 12 weeks from 8 weeks of age to examine the impact of diet-induced obesity on metabolic parameters in the heart. The HFD resulted in an increase in cardiac fatty acid oxidation and a decrease in cardiac glucose oxidation and insulin-stimulated cardiac glucose clearance; however, there was no difference in Hsp72 Tg or Hsp72 KO mice in these rates compared with their respective wild-type control mice. Although HFD-induced cardiac insulin resistance was not rescued in the Hsp72 Tg mice, it was preserved in the skeletal muscle, suggesting tissue-specific effects of Hsp72 overexpression on substrate metabolism. Comparison of two different strains of mice (BALB/c vs. C57BL/6J) also identified strain-specific differences in regard to HFD-induced cardiac lipid accumulation and insulin resistance. These strain differences suggest that cardiac lipid accumulation can be dissociated from cardiac insulin resistance. Our study finds that genetic manipulation of Hsp72 does not lead to alterations in metabolic processes in cardiac tissue under resting conditions, but identifies mouse strain-specific differences in cardiac lipid accumulation and insulin-stimulated glucose clearance.
History
Publication title
Cell Stress and ChaperonesVolume
20Pagination
461-472ISSN
1355-8145Department/School
School of Health SciencesPublisher
Alliance Communications Group Division Allen PressPlace of publication
810 East 10Th Street, Lawrence, USA, Ks, 66044Rights statement
Copyright 2015 Cell Stress Society InternationalRepository Status
- Restricted