Impaired coronary metabolic dilation in the metabolic syndrome is linked to mitochondrial dysfunction and mitochondrial DNA damage.

Title

Impaired coronary metabolic dilation in the metabolic syndrome is linked to mitochondrial dysfunction and mitochondrial DNA damage.

Creator

Guarini Giacinta; Kiyooka Takahiko; Ohanyan Vahagn; Pung Yuh Fen; Marzilli Mario; Chen Yeong-Renn; Chen Chwen-Lih; Kang Patrick T; Hardwick James P; Kolz Christopher L; Yin Liya; Wilson Glenn L; Shokolenko Inna; Dobson James G Jr; Fenton Richard; Chilian William M

Publisher

Basic research in cardiology

Date

2016
2016-05

Description

Mitochondrial dysfunction in obesity and diabetes can be caused by excessive production of free radicals, which can damage mitochondrial DNA. Because mitochondrial DNA plays a key role in the production of ATP necessary for cardiac work, we hypothesized that mitochondrial dysfunction, induced by mitochondrial DNA damage, uncouples coronary blood flow from cardiac work. Myocardial blood flow (contrast echocardiography) was measured in Zucker lean (ZLN) and obese fatty (ZOF) rats during increased cardiac metabolism (product of heart rate and arterial pressure, i.v. norepinephrine). In ZLN increased metabolism augmented coronary blood flow, but in ZOF metabolic hyperemia was attenuated. Mitochondrial respiration was impaired and ROS production was greater in ZOF than ZLN. These were associated with mitochondrial DNA (mtDNA) damage in ZOF. To determine if coronary metabolic dilation, the hyperemic response induced by heightened cardiac metabolism, is linked to mitochondrial function we introduced recombinant proteins (intravenously or intraperitoneally) in ZLN and ZOF to fragment or repair mtDNA, respectively. Repair of mtDNA damage restored mitochondrial function and metabolic dilation, and reduced ROS production in ZOF; whereas induction of mtDNA damage in ZLN reduced mitochondrial function, increased ROS production, and attenuated metabolic dilation. Adequate metabolic dilation was also associated with the extracellular release of ADP, ATP, and H2O2 by cardiac myocytes; whereas myocytes from rats with impaired dilation released only H2O2. In conclusion, our results suggest that mitochondrial function plays a seminal role in connecting myocardial blood flow to metabolism, and integrity of mtDNA is central to this process.

Subject

Animal; Animals; Coronary circulation; Coronary microcirculation; Coronary Vessels/metabolism/*physiopathology; Diabetes; Disease Models; DNA; DNA Damage/physiology; DNA Fragmentation; Metabolic Syndrome/metabolism/*physiopathology; Mitochondria; Mitochondria/*metabolism; Mitochondrial/*metabolism; Obesity; Oxidative Stress/physiology; Rats; Reactive Oxygen Species/metabolism; Vasodilation/physiology; Zucker

Rights

Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).

Pages

29–29

Issue

3

Volume

111

Citation

Guarini Giacinta; Kiyooka Takahiko; Ohanyan Vahagn; Pung Yuh Fen; Marzilli Mario; Chen Yeong-Renn; Chen Chwen-Lih; Kang Patrick T; Hardwick James P; Kolz Christopher L; Yin Liya; Wilson Glenn L; Shokolenko Inna; Dobson James G Jr; Fenton Richard; Chilian William M, “Impaired coronary metabolic dilation in the metabolic syndrome is linked to mitochondrial dysfunction and mitochondrial DNA damage.,” NEOMED Bibliography Database, accessed October 17, 2021, https://neomed.omeka.net/items/show/3179.

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