Planta Med 2016; 82(S 01): S1-S381
DOI: 10.1055/s-0036-1596931
Abstracts
Georg Thieme Verlag KG Stuttgart · New York

Manipulation of NOS activity in the context of glucose stress alters AMPK and mitochondrial oxphos protein content

Authors

  • AC Keller

    1   Department of Endocrinology, Metabolism & Diabetes, University of Colorado, 13001 E. 17th Place, Aurora, CO 80045
    2   Denver VA Medical Center, 1055 Clermont Street, Denver, CO 80220

  • LA Knaub

    1   Department of Endocrinology, Metabolism & Diabetes, University of Colorado, 13001 E. 17th Place, Aurora, CO 80045
    2   Denver VA Medical Center, 1055 Clermont Street, Denver, CO 80220

  • PM McClatchey

    1   Department of Endocrinology, Metabolism & Diabetes, University of Colorado, 13001 E. 17th Place, Aurora, CO 80045
    2   Denver VA Medical Center, 1055 Clermont Street, Denver, CO 80220
    3   Department of Bioengineering, University of Colorado, 13001 E. 17th Place, Aurora, CO 80045

  • CA Connon

    1   Department of Endocrinology, Metabolism & Diabetes, University of Colorado, 13001 E. 17th Place, Aurora, CO 80045
    2   Denver VA Medical Center, 1055 Clermont Street, Denver, CO 80220

  • JEB Reusch

    1   Department of Endocrinology, Metabolism & Diabetes, University of Colorado, 13001 E. 17th Place, Aurora, CO 80045
    2   Denver VA Medical Center, 1055 Clermont Street, Denver, CO 80220
Further Information

Publication History

Publication Date:
14 December 2016 (online)

Also available at
 
 

Diabetes (DM), a worldwide health threat, confers an excess risk of cardiovascular disease, preceded by dysfunction in vascular contractility [1 – 3]. Nitric oxide (NO), produced by nitric oxide synthase (NOS), regulates vascular contractility and mitochondrial function. In DM, excess reactive oxygen species (ROS) can result in NOS uncoupling thereby decreasing NO production and increasing NOS mediated ROS production [4]. It is unknown whether restoration of NOS activity and/or mitochondrial function will improve vascular function in DM. We hypothesized that (-)-epicatechin (EPICAT), a flavonoid compound found in many plants consumed as food, would recouple NOS and clarify the consequences of NOS uncoupling by elevated glucose. We incubated human umbilical vein endothelial cells with 0.1 and 1.0µM of EPICAT in control (7 mM, LG) or high glucose (30 mM, HG) environments for 30 minutes and 4 hours. EPICAT incubation decreased AMPK and eNOS activity, increased SIRT3 and decreased MnSOD expression (p < 0.05 for all) after 30 minutes. After 4 hours, EPICAT decreased eNOS activity and mitochondrial complexes II, III, IV, and V (p < 0.05 for all). Preliminary microscopy experiments suggest that EPICAT may modulate mitochondrial biogenesis. In summary, manipulation of eNOS and NO production in cells exposed to glucose mediated stress results in inhibition of the AMPK/eNOS/PGC-1α pathway and impacts mitochondrial complex expression. This appears to be part of a homeostatic function of eNOS that could be impaired in DM. EPICAT may modulate the cells' adaptation to nutrient stress, either by supporting NOS function or by restoring multiple points in a particular signaling pathway. Current work investigates further cellular signaling and alterations in mitochondrial dynamics and respiration.

Acknowledgements: The Colorado Nutrition Obesity Research Center Pilot Award and VA Merit award funded this study.

Keywords: (-)-epicatechin, mitochondria, diabetes, nitric oxide synthase.

References:

[1] Bloomgarden Z. Cardiovascular disease and diabetes. Diabetes Care 2003; 26: 230 – 237

[2] Wu J, Li Q, Wang X, Yu S, Li L, Wu X, Chen Y, Zhao J, Zhao Y. Neuroprotection by curcumin in ischemic brain injury involves the Akt/Nrf2 pathway. PLoS One 2013; 8: e59843

[3] Gibbons GH, Dzau VJ. The emerging concept of vascular remodeling. N Engl J Med 1994; 19: 1431 – 1438

[4] Valerio A, Nisoli E. Nitric oxide, interorganelle communication, and energy flow: a novel route to slow aging. Front Cell Dev Biol 2015; 3: 6


No conflict of interest has been declared by the author(s).