Reduced NAD(P)H oxidase in low renin hypertension: link among angiotensin II, atherogenesis, and blood pressure.
Endothelial dysfunction (ED) complicates hypertension and is a precursor of atherosclerosis. Reduced NO bioactivity, because of increased reduced NAD(P)H oxidase-derived reactive oxygen species (ROS), plays a critical role in ED. gp91phox, predominantly expressed in the endothelium and adventitia, is a subunit of NAD(P)H oxidase important for its activation in response to angiotensin (Ang) II. Human atherosclerotic plaques are heavy laden with gp91phox. We have shown that in Dahl salt-sensitive (DS) rats, a paradigm of low renin salt-sensitive (SS) hypertension in humans, Ang II receptor blockade normalizes ROS production and endothelium-dependent relaxation (EDR) without significantly affecting systolic blood pressure (SBP). To additionally elucidate the mechanisms involved in the functional association of Ang II in SS hypertension, we administered a cell-permeable inhibitor of the assembly of p47phox with gp91phox in NAD(P)H oxidase, gp91ds-tat (10 mg/kg body weight, 3 weeks by minipump), to DS rats fed a 4% salt diet. Control rats received either vehicle or an inactive scramb-tat peptide. Vehicle-treated DS developed hypertension (SBP 168+/-5 mm Hg), left ventricular hypertrophy (LVH), proteinuria, impaired EDR, and increased aortic ROS production (superoxide 115% and peroxynitrite 157%) and expression of the proatherogenic molecules LOX-1 (130%) and MCP-1 (166%). gp91ds-tat, but not scramb-tat, normalized ROS and EDR, as well as LOX-1 and MCP-1, despite nonsignificant effects on SBP (159+/-5 mm Hg; P>0.05), left ventricular hypertrophy, and proteinuria. Our findings support the notion that in SS hypertension, activation of NAD(P)H oxidase promotes ED and atherogenesis via decreased nitric oxide bioactivity and increased LOX-1 and MCP-1, independent of blood pressure.
Zhou
Ming-Sheng
MS
Veterans Affairs Medical Center, Division of Nephrology and Hypertension, Vascular Biology Institute, University of Miami Miller School of Medicine, Miami, FL, USA.
Hernandez Schulman
Ivonne
I
Pagano
Patrick J
PJ
Jaimes
Edgar A
EA
Raij
Leopoldo
L
D000109:Acetylcholine / Q000494:pharmacology; D000804:Angiotensin II / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000378:metabolism; D050197:Atherosclerosis / Q000209:etiology*; D001794:Blood Pressure / Q000187:drug effects; D018932:Chemokine CCL2 / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000503:physiopathology; D006973:Hypertension / Q000097:blood / Q000201:enzymology / Q000378:metabolism* / Q000503:physiopathology; D017379:Hypertrophy, Left Ventricular / Q000139:chemically induced; D066298:In Vitro Techniques; D008562:Membrane Glycoproteins / Q000172:deficiency; D051379:Mice; D018345:Mice, Knockout; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000172:deficiency / Q000378:metabolism*; D009994:Osmolar Concentration; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D020303:Rats, Inbred Dahl; D012083:Renin / Q000097:blood*; D051127:Scavenger Receptors, Class E / Q000235:genetics; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage / Q000494:pharmacology; D013599:Systole; D014662:Vasoconstrictor Agents / Q000378:metabolism* / Q000494:pharmacology; D014664:Vasodilation; D014665:Vasodilator Agents / Q000494:pharmacology
C491766:Ccl2 protein, rat; D018932:Chemokine CCL2; D008562:Membrane Glycoproteins; C495136:OLR1 protein, rat; D012333:RNA, Messenger; D051127:Scavenger Receptors, Class E; D017673:Sodium Chloride, Dietary; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D000804:Angiotensin II; C488842:Cybb protein, mouse; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; D012083:Renin; D000109:Acetylcholine