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SIRT Is Required for EDP-Mediated Protective Responses toward Hypoxia-Reoxygenation Injury in Cardiac Cells
Victor Samokhvalov1, Kristi L Jamieson1, Ilia Fedotov2
1Faculty of Pharmacy and Pharmaceutical Sciences, Katz Group Centre for Pharmacy and Health Research, University of Alberta Edmonton, AB, Canada.
Abstract:
Hypoxia-reoxygenation (H/R) injury is known to cause extensive injury to cardiac myocardium promoting development of cardiac dysfunction. Despite the vast number of studies dedicated to studying H/R injury, the molecular mechanisms behind it are multiple, complex, and remain very poorly understood, which makes development of novel pharmacological agents challenging. Docosahexaenoic acid (DHA, 22:6n3) is an n - 3 polyunsaturated fatty acid obtained from dietary sources, which produces numerous effects including regulation of cell survival and death mechanisms. The beneficial effects of DHA toward the cardiovascular system are well documented but the relative role of DHA or one of its more potent metabolites is unresolved. Emerging evidence indicates that cytochrome P450 (CYP) epoxygenase metabolites of DHA, epoxydocosapentaenoic acids (EDPs), have more potent biological activity than DHA in cardiac cells. In this study we examined whether EDPs protect HL-1 cardiac cells from H/R injury. Our observations demonstrate that treatment with 19,20-EDP protected HL-1 cardiac cells from H/R damage through a mechanism(s) protecting and enhancing mitochondrial quality. EDP treatment increased the relative rates of mitobiogenesis and mitochondrial respiration in control and H/R exposed cardiac cells. The observed EDP protective response toward H/R injury involved SIRT1-dependent pathways.
Insights
Epoxydocosapentaenoic acids (EDPs), metabolites of docosahexaenoic acid (DHA), protect cardiac cells from hypoxia-reoxygenation injury. EDPs enhance mitochondrial function and quality, involving SIRT1-dependent pathways for cardioprotection.
Area of Science:
- Cardiovascular Biology
- Mitochondrial Medicine
- Molecular Cardiology
Background:
- Hypoxia-reoxygenation (H/R) injury causes significant cardiac dysfunction.
- The molecular mechanisms of H/R injury are complex and poorly understood, hindering therapeutic development.
- Docosahexaenoic acid (DHA) has known cardiovascular benefits, but its specific metabolites' roles are unclear.
Purpose of the Study:
- To investigate the protective effects of epoxydocosapentaenoic acids (EDPs), DHA metabolites, against H/R injury in cardiac cells.
- To elucidate the mechanisms underlying EDP-mediated cardioprotection, focusing on mitochondrial quality and function.
Main Methods:
- Utilized HL-1 cardiac cells exposed to hypoxia-reoxygenation (H/R) injury.
- Administered 19,20-EDP, a specific DHA metabolite, to assess its protective effects.
- Evaluated mitochondrial biogenesis, respiration, and quality in response to EDP treatment.
Main Results:
- 19,20-EDP treatment significantly protected HL-1 cardiac cells from H/R-induced damage.
- EDP enhanced mitochondrial quality and increased rates of mitochondrial biogenesis and respiration.
- The protective effects of EDP involved SIRT1-dependent signaling pathways.
Conclusions:
- Epoxydocosapentaenoic acids (EDPs) demonstrate potent cardioprotective effects against H/R injury.
- EDP-mediated protection is linked to improved mitochondrial health and function.
- SIRT1 pathways are implicated in the beneficial actions of EDPs in cardiac cells.
