SCOPE: Activation of endothelial adenosine monophosphate-activated protein kinase (AMPK) contributes to increase nitric oxide (NO) availability. The aim of this study was to assess if high-fat diet (HFD)-induced endothelial dysfunction is linked to AMPK deregulation. METHODS AND RESULTS: Twelve-week-old Sprague Dawley male rats were assigned either to control (10 kcal % from fat) or to HFD (45 kcal % from fat) for 8 wk. HFD rats segregated in obesity-prone (OP) or obesity-resistant (OR) rats according to body weight. HFD triggered an impaired glucose management together with impaired endothelium-dependent relaxation, reduced endothelial AMPK activity and lower NO availability in aortic rings of OP and OR cohorts. Relaxation evoked by AMPK activator, 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR) was reduced in both OP and OR rings, which exhibited lower p-AMPKα-Thr(172) /AMPKα ratios that negatively correlated with plasma non-esterified fatty acids (NEFA) and triglycerides (TG). Inhibition of PI3K (wortmannin, 10(-7) M) or Akt (triciribine, 10(-5) M) reduced relaxation to AICAR only in the control group (p < 0.001). Akt (p-Akt-Ser(473) ) and eNOS phosphorylation (p-eNOS-Ser(1177) ) were significantly reduced in OP and OR (p < 0.01). CONCLUSION: Endothelial dysfunction caused by HFD is related to a dysfunctional endothelial AMPK-PI3K-Akt-eNOS pathway correlating with the increase of plasma NEFA, TG, and an impaired glucose management.
SCOPE: Activation of endothelial adenosine monophosphate-activated protein kinase (AMPK) contributes to increase nitric oxide (NO) availability. The aim of this study was to assess if high-fat diet (HFD)-induced endothelial dysfunction is linked to AMPK deregulation. METHODS AND RESULTS: Twelve-week-old Sprague Dawley male rats were assigned either to control (10 kcal % from fat) or to HFD (45 kcal % from fat) for 8 wk. HFD rats segregated in obesity-prone (OP) or obesity-resistant (OR) rats according to body weight. HFD triggered an impaired glucose management together with impaired endothelium-dependent relaxation, reduced endothelial AMPK activity and lower NO availability in aortic rings of OP and OR cohorts. Relaxation evoked by AMPK activator, 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR) was reduced in both OP and OR rings, which exhibited lower p-AMPKα-Thr(172) /AMPKα ratios that negatively correlated with plasma non-esterified fatty acids (NEFA) and triglycerides (TG). Inhibition of PI3K (wortmannin, 10(-7) M) or Akt (triciribine, 10(-5) M) reduced relaxation to AICAR only in the control group (p < 0.001). Akt (p-Akt-Ser(473) ) and eNOS phosphorylation (p-eNOS-Ser(1177) ) were significantly reduced in OP and OR (p < 0.01). CONCLUSION:Endothelial dysfunction caused by HFD is related to a dysfunctional endothelial AMPK-PI3K-Akt-eNOS pathway correlating with the increase of plasma NEFA, TG, and an impaired glucose management.
Authors: Jana Rathouska; Petra Fikrova; Alena Mrkvicova; Katerina Blazickova; Michala Varejckova; Eva Dolezelova; Ivana Nemeckova; Barbora Vitverova; Lenka Peslova; Eunate Gallardo-Vara; Miguel Pericacho; Petr Nachtigal Journal: Heart Vessels Date: 2017-04-05 Impact factor: 2.037
Authors: J K Lauridsen; R H Olesen; J Vendelbo; T M Hyde; J E Kleinman; B M Bibby; B Brock; J Rungby; A Larsen Journal: Transl Psychiatry Date: 2017-02-28 Impact factor: 6.222