Impaired vasodilator activity in deoxycorticosterone acetate-salt hypertension is associated with increased protein O-GlcNAcylation.
Hyperglycemia, which increases O-linked beta-N-acetylglucosamine (O-GlcNAc) proteins, leads to changes in vascular reactivity. Because vascular dysfunction is a key feature of arterial hypertension, we hypothesized that vessels from deoxycorticosterone acetate and salt (DOCA-salt) rats exhibit increased O-GlcNAc proteins, which is associated with increased reactivity to constrictor stimuli. Aortas from DOCA rats exhibited increased contraction to phenylephrine (E(max) [mN]=17.6+/-4 versus 10.7+/-2 control; n=6) and decreased relaxation to acetylcholine (47.6+/-6% versus 73.2+/-10% control; n=8) versus arteries from uninephrectomized rats. O-GlcNAc protein content was increased in aortas from DOCA rats (arbitrary units=3.8+/-0.3 versus 2.3+/-0.3 control; n=5). PugNAc (O-GlcNAcase inhibitor; 100 micromol/L; 24 hours) increased vascular O-GlcNAc proteins, augmented phenylephrine vascular reactivity (18.2+/-2 versus 10.7+/-3 vehicle; n=6), and decreased acetylcholine dilation in uninephrectomized (41.4+/-6 versus 73.2+/-3 vehicle; n=6) but not in DOCA rats (phenylephrine, 16.5+/-3 versus 18.6+/-3 vehicle, n=6; acetylcholine, 44.7+/-8 versus 47.6+/-7 vehicle, n=6). PugNAc did not change total vascular endothelial nitric oxide synthase levels, but reduced endothelial nitric oxide synthase(Ser-1177) and Akt(Ser-473) phosphorylation (P<0.05). Aortas from DOCA rats also exhibited decreased levels of endothelial nitric oxide synthase(Ser-1177) and Akt(Ser-473) (P<0.05) but no changes in total endothelial nitric oxide synthase or Akt. Vascular O-GlcNAc-modified endothelial nitric oxide synthase was increased in DOCA rats. Blood glucose was similar in DOCA and uninephrectomized rats. Expression of O-GlcNAc transferase, glutamine:fructose-6-phosphate amidotransferase, and O-GlcNAcase, enzymes that directly modulate O-GlcNAcylation, was decreased in arteries from DOCA rats (P<0.05). This is the first study showing that O-GlcNAcylation modulates vascular reactivity in normoglycemic conditions and that vascular O-GlcNAc proteins are increased in DOCA-salt hypertension. Modulation of increased vascular O-GlcNAcylation may represent a novel therapeutic approach in mineralocorticoid hypertension.
Lima
Victor V
VV
Medical College of Georgia, Department of Physiology, 1120 Fifteenth St, CA-3141, Augusta, GA 30912-3000, USA. vlima@mcg.edu
Giachini
Fernanda R C
FR
Choi
Hyehun
H
Carneiro
Fernando S
FS
Carneiro
Zidonia N
ZN
Fortes
Zuleica B
ZB
Carvalho
Maria Helena C
MH
Webb
R Clinton
RC
Tostes
Rita C
RC
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000503:physiopathology*; D003900:Desoxycorticosterone; D004195:Disease Models, Animal; D005945:Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing) / Q000378:metabolism*; D006973:Hypertension / Q000139:chemically induced / Q000503:physiopathology*; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects / Q000503:physiopathology*; D017351:N-Acetylglucosaminyltransferases / Q000378:metabolism*; D010656:Phenylephrine / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology*; D014665:Vasodilator Agents / Q000494:pharmacology; D001619:beta-N-Acetylhexosaminidases / Q000378:metabolism*
D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D010656:Phenylephrine; D003900:Desoxycorticosterone; D017351:N-Acetylglucosaminyltransferases; C063057:UDP-N-acetylglucosamine-peptide beta-N-acetylglucosaminyltransferase; D005945:Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing); C110628:hexosaminidase C; D001619:beta-N-Acetylhexosaminidases; D000109:Acetylcholine