Protoporphyrin IX generation from δ-aminolevulinic acid elicits pulmonary artery relaxation and soluble guanylate cyclase activation

2006 ◽  
Vol 291 (3) ◽  
pp. L337-L344 ◽  
Author(s):  
Christopher J. Mingone ◽  
Sachin A. Gupte ◽  
Joseph L. Chow ◽  
Mansoor Ahmad ◽  
Nader G. Abraham ◽  
...  
Keyword(s):  
Guanylate Cyclase ◽  
Vascular Function ◽  
Soluble Guanylate Cyclase ◽  
Aminolevulinic Acid ◽  
Pulmonary Arteries ◽  
Protoporphyrin Ix ◽  
Physiological Mechanism ◽  
No Donor ◽  
Vasp Phosphorylation ◽  
Guanylate Cyclase Activation

Protoporphyrin IX is an activator of soluble guanylate cyclase (sGC), but its role as an endogenous regulator of vascular function through cGMP has not been previously reported. In this study we examined whether the heme precursor δ-aminolevulinic acid (ALA) could regulate vascular force through promoting protoporphyrin IX-elicited activation of sGC. Exposure of endothelium-denuded bovine pulmonary arteries (BPA) in organoid culture to increasing concentrations of the heme precursor ALA caused a concentration-dependent increase in BPA epifluorescence, consistent with increased tissue protoporphyrin IX levels, associated with decreased force generation to increasing concentrations of serotonin. The force-depressing actions of 0.1 mM ALA were associated with increased cGMP-associated vasodilator-stimulated phosphoprotein (VASP) phosphorylation and increased sGC activity in homogenates of BPA cultured with ALA. Increasing iron availability with 0.1 mM FeSO4 inhibited the decrease in contraction to serotonin and increase in sGC activity caused by ALA, associated with decreased protoporphyrin IX and increased heme. Chelating endogenous iron with 0.1 mM deferoxamine increased the detection of protoporphyrin IX and force depressing activity of 10 μM ALA. The inhibition of sGC activation with the heme oxidant 10 μM 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) attenuated the force depressing actions of an NO donor without altering the actions of ALA. Thus control of endogenous formation of protoporphyrin IX from ALA by the availability of iron is potentially a novel physiological mechanism of controlling vascular function through regulating the activity of sGC.

NADPH and heme redox modulate pulmonary artery relaxation and guanylate cyclase activation by NO

1999 ◽  
Vol 277 (6) ◽  
pp. L1124-L1132 ◽  
Author(s):  
Sachin A. Gupte ◽  
Tasneem Rupawalla ◽  
Donald Phillibert ◽  
Michael S. Wolin
Keyword(s):  
Nitric Oxide ◽  
Guanylate Cyclase ◽  
Soluble Guanylate Cyclase ◽  
Pulmonary Arteries ◽  
Redox Status ◽  
Pentose Phosphate ◽  
Inhibitory Effects ◽  
No Donor ◽  
Guanylate Cyclase Activation ◽  
Stimulation Of

The hemoprotein oxidant ferricyanide (FeCN) converts the iron of the heme on soluble guanylate cyclase (sGC) from Fe2+ to Fe3+, which prevents nitric oxide (NO) from binding the heme and stimulating sGC activity. This study uses FeCN to examine whether modulation of the redox status of the heme on sGC influences the relaxation of endothelium-removed bovine pulmonary arteries (BPA) to NO. Pretreatment of the homogenate of BPA with 50 μM FeCN resulted in a loss of stimulation of sGC activity by the NO donor 10 μM S-nitroso- N-acetylpenicillamine (SNAP). In the FeCN-treated homogenate reconcentrated to the enzyme levels in BPA, 100 μM NADPH restored NO stimulation of sGC, and this effect of NADPH was prevented by an inhibitor of flavoprotein electron transport, 1 μM diphenyliodonium (DPI). In BPA the relaxation to SNAP was not altered by FeCN, inhibitors of NADPH generation by the pentose phosphate pathway [250 μM 6-aminonicotinamide (6-AN) and 100 μM epiandrosterone (Epi)], or 1 μM DPI. However, the combination of FeCN with 6-AN, Epi, or DPI inhibited ( P < 0.05) relaxation to SNAP without significantly altering the relaxation of BPA to forskolin. The inhibitory effects of 1 μM 1 H-[1,2,4]oxadiazolo[4,3- a]quinoxalin-1-one (a probe that appears to convert NO-heme of sGC to its Fe3+-heme form) on relaxation to SNAP were also enhanced by DPI. These observations suggest that a flavoprotein containing NADPH oxidoreductase may influence cGMP-mediated relaxation of BPA to NO by maintaining the heme of sGC in its Fe2+ oxidation state.

Hypoxia enhances a cGMP-independent nitric oxide relaxing mechanism in pulmonary arteries

2003 ◽  
Vol 285 (2) ◽  
pp. L296-L304 ◽  
Author(s):  
Christopher J. Mingone ◽  
Sachin A. Gupte ◽  
Takafumi Iesaki ◽  
Michael S. Wolin
Keyword(s):  
Nitric Oxide ◽  
Sarcoplasmic Reticulum ◽  
Myosin Light Chain ◽  
Soluble Guanylate Cyclase ◽  
Pulmonary Arteries ◽  
Cyclopiazonic Acid ◽  
No Donor ◽  
No Donors ◽  
Hypoxic Conditions ◽  
Guanylate Cyclase Activation

Nitric oxide (NO) donors generally relax vascular preparations through cGMP-mediated mechanisms. Relaxation of endothelium-denuded bovine pulmonary arteries (BPA) and coronary arteries to the NO donor S-nitroso- N-acetyl-penicillamine (SNAP) is almost eliminated by inhibition of soluble guanylate cyclase activation with 10 μM 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one (ODQ), whereas only a modest inhibition of relaxation is observed under hypoxia (PO2 = 8–10 Torr). This effect of hypoxia is independent of the contractile agent used and is also observed with NO gas. ODQ eliminated SNAP-induced increases in cGMP under hypoxia in BPA. cGMP-independent relaxation of BPA to SNAP was not attenuated by inhibition of K+ channels (10 mM tetraethylammonium), myosin light chain phosphatase (0.5 μM microcystin-LR), or adenylate cyclase (4 μM 2′,5′-dideoxyadenosine). SNAP relaxed BPA contracted with serotonin under Ca2+-free conditions in the presence of hypoxia and ODQ, and contraction to Ca2+ readdition was also attenuated. The sarcoplasmic reticulum Ca2+-reuptake inhibitor cyclopiazonic acid (0.2 mM) attenuated SNAP-mediated relaxation of BPA in the presence of ODQ. Thus hypoxic conditions appear to promote a cGMP-independent relaxation of BPA to NO by enhancing sarcoplasmic reticulum Ca2+ reuptake.

scholarly journals Exposure of mice to chronic hypoxia attenuates pulmonary arterial contractile responses to acute hypoxia by increases in extracellular hydrogen peroxide

2014 ◽  
Vol 307 (4) ◽  
pp. R426-R433 ◽  
Author(s):  
Dhara Patel ◽  
Raed Alhawaj ◽  
Michael S. Wolin
Keyword(s):  
Hydrogen Peroxide ◽  
Pulmonary Hypertension ◽  
Chronic Hypoxia ◽  
Soluble Guanylate Cyclase ◽  
Aminolevulinic Acid ◽  
Acute Hypoxia ◽  
Pulmonary Arteries ◽  
Protoporphyrin Ix

Exposing mice to a chronic hypoxic treatment (10% oxygen, 21 days) that promotes pulmonary hypertension was observed to attenuate the pulmonary vasoconstriction response to acute hypoxia (HPV) both in vivo and in isolated pulmonary arteries. Since catalase restored the HPV response in isolated arteries, it appeared to be attenuated by extracellular hydrogen peroxide. Chronic hypoxia promoted the detection of elevated lung superoxide, extracellular peroxide, extracellular SOD expression, and protein kinase G (PKG) activation [based on PKG dimerization and vasodilator-stimulated phosphoprotein (VASP) phosphorylation], suggesting increased generation of extracellular peroxide and PKG activation may contribute to the suppression of HPV. Aorta from mice exposed to 21 days of hypoxia also showed evidence for extracellular hydrogen peroxide, suppressing the relaxation response to acute hypoxia. Peroxide appeared to partially suppress contractions to phenylephrine used in the study of in vitro hypoxic responses. Treatment of mice with the heme precursor δ-aminolevulinic acid (ALA; 50 mg·kg−1·day−1) during exposure to chronic hypoxia was examined as a pulmonary hypertension therapy because it could potentially activate beneficial cGMP-mediated effects through promoting a prolonged protoporphyrin IX (PpIX)-elicited activation of soluble guanylate cyclase. ALA attenuated pulmonary hypertension, increases in both superoxide and peroxide, and the suppression of in vitro and in vivo HPV responses. ALA generated prolonged detectible increases in PpIX and PKG-associated phosphorylation of VASP, suggesting PKG activation may contribute to suppression of pulmonary hypertension and prevention of alterations in extracellular peroxide that appear to be attenuating HPV responses caused by chronic hypoxia.

Regulation of NO-elicited pulmonary artery relaxation and guanylate cyclase activation by NADH oxidase and SOD

1999 ◽  
Vol 276 (5) ◽  
pp. H1535-H1542 ◽  
Author(s):  
Sachin A. Gupte ◽  
Tasneem Rupawalla ◽  
Kamal M. Mohazzab-H. ◽  
Michael S. Wolin
Keyword(s):  
Guanylate Cyclase ◽  
Soluble Guanylate Cyclase ◽  
Nadh Oxidase ◽  
Pulmonary Arteries ◽  
Redox Status ◽  
Inhibitory Effects ◽  
Sod Activity ◽  
Text Production ◽  
Dehydrogenase Reaction ◽  
Guanylate Cyclase Activation

We have previously reported that inhibition of Cu/Zn superoxide dismutase (SOD) in endothelium-removed bovine pulmonary arteries (BPA) attenuates nitrovasodilator-elicited relaxation and that a NADH oxidase linked to the redox status of cytosolic NADH is the major detectable source of superoxide ([Formula: see text]) production in this tissue. In the present study, we investigated whether NADH oxidase-derived[Formula: see text] participated in inhibition of nitrovasodilator-elicited relaxation and soluble guanylate cyclase (sGC) stimulation. Lactate (10 mM) and pyruvate (10 mM) were employed to increase and decrease, respectively, NADH-dependent[Formula: see text] production in the BPA presumably by modulating cytosolic NAD(H) through the lactate dehydrogenase reaction. A 30-min pretreatment with 10 mM diethyldithiocarbamate (DETCA) was used to inhibit Cu/Zn SOD, and S-nitroso- N-acetylpenicillamine (SNAP) was employed as a source of nitric oxide (NO). Lactate or pyruvate did not alter relaxation to NO. However, when the response to NO was inhibited by DETCA, lactate potentiated and pyruvate reduced the inhibitory effects of DETCA. SOD attenuated the inhibitory effects of DETCA plus lactate. In the presence of 10 μM SNAP, the activity of sGC in a BPA homogenate preparation (which was reconcentrated to approximate tissue conditions) was not altered by SOD. However, NADH (0.1 mM) decreased sGC activity by 70%, and this effect of NADH was attenuated in the presence of SOD. Thus cytosolic NADH redox and Cu/Zn SOD activity have important roles in controlling the inhibitory effects of [Formula: see text] derived from NADH oxidase on sGC activity and cGMP-mediated relaxation to nitrovasodilators in BPA.

scholarly journals Direct soluble guanylate cyclase activation improves vascular function in a mouse model of sickle cell disease

Nitric Oxide ◽  
2014 ◽  
Vol 42 ◽  
pp. 138
Author(s):  
Karin Potoka ◽  
Christina Mucci ◽  
Stephanie Mutchler ◽  
Marta Bueno ◽  
Eva Becker-Pelster ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Mouse Model ◽  
Sickle Cell ◽  
Guanylate Cyclase ◽  
Vascular Function ◽  
Soluble Guanylate Cyclase ◽  
Cell Disease ◽  
Cyclase Activation ◽  
Guanylate Cyclase Activation

scholarly journals Heme oxygenase-1 induction depletes heme and attenuates pulmonary artery relaxation and guanylate cyclase activation by nitric oxide

2008 ◽  
Vol 294 (3) ◽  
pp. H1244-H1250 ◽  
Author(s):  
Christopher J. Mingone ◽  
Mansoor Ahmad ◽  
Sachin A. Gupte ◽  
Joseph L. Chow ◽  
Michael S. Wolin
Keyword(s):  
Nitric Oxide ◽  
Pulmonary Artery ◽  
Organ Culture ◽  
Heme Oxygenase ◽  
Guanylate Cyclase ◽  
Soluble Guanylate Cyclase ◽  
Pulmonary Arteries ◽  
Heme Oxygenase 1 ◽  
No Donor ◽  
Spermine Nonoate

This study examines in endothelium-denuded bovine pulmonary arteries the effects of increasing heme oxygenase-1 (HO-1) activity on relaxation and soluble guanylate cyclase (sGC) activation by nitric oxide (NO). A 24-h organ culture with 0.1 mM cobalt chloride (CoCl2) or 30 μM Co-protoporphyrin IX was developed as a method of increasing HO-1 expression. These treatments increased HO-1 expression and HO activity by approximately two- to fourfold and lowered heme levels by 40–45%. Induction of HO-1 was associated with an attenuation of pulmonary arterial relaxation to the NO-donor spermine-NONOate. The presence of a HO-1 inhibitor 30 μM chromium mesoporphyrin during the 24-h organ culture (but not acute treatment with this agent) reversed the attenuation of relaxation to NO seen in arteries co-cultured with agents that increased HO-1. Relaxation to isoproterenol, which is thought to be mediated through cAMP, was not altered in arteries with increased HO-1. Inducers of HO-1 did not appear to alter basal sGC activity in arterial homogenates or expression of the β1-subunit of sGC. However, the increase in activity seen in the presence of 1 μM spermine-NONOate was attenuated in homogenates obtained from arteries with increased HO-1. Since arteries with increased HO-1 had decreased levels of superoxide detected by the chemiluminescence of 5 μM lucigenin, superoxide did not appear to be mediating the attenuation of relaxation to NO. These data suggest that increasing HO-1 activity depletes heme, and this is associated with an attenuation of pulmonary artery relaxation and sGC activation responses to NO.

Thiol oxidation inhibits nitric oxide-mediated pulmonary artery relaxation and guanylate cyclase stimulation

2006 ◽  
Vol 290 (3) ◽  
pp. L549-L557 ◽  
Author(s):  
Christopher J. Mingone ◽  
Sachin A. Gupte ◽  
Noorjahan Ali ◽  
Richard A. Oeckler ◽  
Michael S. Wolin
Keyword(s):  
Nitric Oxide ◽  
Guanylate Cyclase ◽  
Pentose Phosphate Pathway ◽  
Vascular Function ◽  
Soluble Guanylate Cyclase ◽  
Pulmonary Arteries ◽  
Oxidation Mechanism ◽  
Pentose Phosphate ◽  
Thiol Oxidation ◽  
Thiol Redox

The mechanisms through which thiol oxidation and cellular redox influence the regulation of soluble guanylate cyclase (sGC) are poorly understood. This study investigated whether promoting thiol oxidation via inhibition of NADPH generation by the pentose phosphate pathway (PPP) with 1 mM 6-aminonicotinamide (6-AN) or the thiol oxidant diamide (1 mM) alters sGC activity and cGMP-associated relaxation to nitric oxide (NO) donors [ S-nitroso- N-acetylpenicillamine (SNAP) and spermine-NONOate]. Diamide and 6-AN inhibited NO-elicited relaxation of endothelium-denuded bovine pulmonary arteries (BPA) and stimulation of sGC activity in BPA homogenates. Treatment of BPA with the thiol reductant DTT (1 mM) reversed inhibition of NO-mediated relaxation and sGC stimulation by 6-AN. The increase in cGMP protein kinase-associated phosphorylation of vasodilator-stimulated phosphoprotein on Ser239 elicited by 10 μM SNAP was also inhibited by diamide. Activation of sGC by SNAP was attenuated by low micromolar concentrations of GSSG in concentrated, but not dilute, homogenates of BPA, suggesting that an enzymatic process contributes to the actions of GSSG. Relaxation to agents that function through cAMP (forskolin and isoproterenol) was not altered by inhibition of the pentose phosphate pathway or diamide. Thus a thiol oxidation mechanism controlled by the regulation of thiol redox by NADPH generated via the pentose phosphate pathway appears to inhibit sGC activation and cGMP-mediated relaxation by NO in a manner consistent with its function as an important physiological redox-mediated regulator of vascular function.

scholarly journals Roles for soluble guanylate cyclase and a thiol oxidation-elicited subunit dimerization of protein kinase G in pulmonary artery relaxation to hydrogen peroxide

2010 ◽  
Vol 299 (4) ◽  
pp. H1235-H1241 ◽  
Author(s):  
Boon Hwa Neo ◽  
Sharath Kandhi ◽  
Michael S. Wolin
Keyword(s):  
Nitric Oxide ◽  
Hydrogen Peroxide ◽  
Protein Kinase ◽  
Guanylate Cyclase ◽  
Soluble Guanylate Cyclase ◽  
Pulmonary Arteries ◽  
Protein Kinase G ◽  
Thiol Oxidation ◽  
Organoid Culture ◽  
Vasp Phosphorylation

We have previously provided evidence that hydrogen peroxide (H2O2) stimulates soluble guanylate cyclase (sGC) under conditions where it relaxes isolated endothelium-removed bovine pulmonary arteries (BPAs). Since it was recently reported that H2O2 induces coronary vasorelaxation associated with a nitric oxide/cGMP-independent thiol oxidation/subunit dimerization-elicited activation of protein kinase G (PKG), we investigated whether this mechanism participates in the relaxation of BPAs to H2O2. BPAs precontracted with serotonin (incubated under hypoxia to lower endogenous H2O2) were exposed to increasing concentrations of H2O2. It was observed that 0.1–1 mM H2O2 caused increased PKG dimerization and relaxation. These responses were associated with increased phosphorylation of vasodilator-stimulated phosphoprotein (VASP) at the serine-239 site known to be mediated by PKG. Treatment of BPAs with 1 mM DTT attenuated PKG dimerization, VASP phosphorylation, and relaxation to H2O2. An organoid culture of BPAs for 48 h with 10 μM 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), a heme oxidant inhibitor of sGC activation, depleted sGC expression by 85%, associated with a 67% attenuation of VASP phosphorylation and 48% inhibition of relaxation elicited by 100 μM H2O2. Thus both a sGC activation/cGMP-dependent and a thiol oxidation subunit dimerization/cGMP-independent activation of PKG appear to contribute to the relaxation of BPAs elicited by H2O2.

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