Targeting the heme-oxidized nitric oxide receptor for selective vasodilatation of diseased blood vessels

Abstract

ROS are a risk factor of several cardiovascular disorders and interfere with NO/soluble guanylyl cyclase/ cyclic GMP (NO/sGC/cGMP) signaling through scavenging of NO and formation of the strong oxidant peroxynitrite.Increased oxidative stress affects the heme-containing NO receptor sGC by both decreasing its expression levels and impairing NO-induced activation, making vasodilator therapy with NO donors less effective.Here we show in vivo that oxidative stress and related vascular disease states, including human diabetes mellitus, led to an sGC that was indistinguishable from the in vitro oxidized/heme-free enzyme.This sGC variant represents what we believe to be a novel cGMP signaling entity that is unresponsive to NO and prone to degradation.Whereas high-affinity ligands for the unoccupied heme pocket of sGC such as zinc-protoporphyrin IX and the novel NO-independent sGC activator 4-[((4-carboxybutyl){2-[(4-pheneth ylbenzyl)oxy]phenethyl}amino) methyl [benzoic]acid (BAY 58-2667) stabilized the enzyme, only the latter activated the NO-insensitive sGC variant.Importantly, in isolated cells, in blood vessels, and in vivo, BAY 58-2667 was more effective and potentiated under pathophysiological and oxidative stress conditions.This therapeutic principle preferentially dilates diseased versus normal blood vessels and may have far-reaching implications for the currently investigated clinical use of BAY 58-2667 as a unique diagnostic tool and highly innovative vascular therapy.Nonstandard abbreviations used: BAY 41-2272, 5-cyclopropyl-2-[1-(2-fluoro-benzyl)-1H-pyrazolo[3,4-b]pyridin-3-yl]-pyrimidin-4-ylamine; BAY 58-2667, 4-[((4-carboxybutyl){2-[(4-phenethylbenzyl)oxy] phenethyl}amino) methyl [benzoic]acid; BNP, B-type natriuretic peptide; cGMP, cyclic GMP; DEA/NO, 2-(N,N-diethylamino)-diazenolate-2-oxide; EC50, 50% effective concentration; GTN, glycerol trinitrate; l-NAME, N-nitro-l-arginine methylester; NAC, N-acetyl-cysteine; NZW, New Zealand (rabbits); ODQ, 1H-[1,2,4]oxadiazolo [3,4-a]quinoxalin-1-one; ONOO -, peroxynitrite; PDE, phosphodiesterase; PE, phenylephrine; PPIX, protoporphyrin IX; SIN-1, 3-morpholino-sydnonimine hydrochloride; sGC, soluble guanylyl cyclase; SHR, spontaneously hypertensive rats; TG(mRen2)27 rats, hypertensive transgenic renin rats; U46619, 9,11-dideoxy-9a,11a-methanoepoxyprostaglandin F2a; WHHL, Watanabe heritable hyperlipidemic (rabbits). Conflict of interest:Johannes-Peter Stasch and Andreas Knorr are currently full-time employees of Bayer HealthCare.Peter M. Schmidt was employed from 2000 to 2003 by Bayer HealthCare.Harald Lapp is the principal investigator of a clinical study of patients with acute decompensated heart failure using BAY 58-2667.Adrian Tersteegen is currently employed by Bayer HealthCare.