bay-58-2667 and Hypertension--Pulmonary

Nitric oxide (NO) activates soluble guanylate cyclase (sGC) by binding its prosthetic heme group, thereby catalyzing cyclic guanosine monophosphate (cGMP) synthesis. cGMP causes vasodilation and may inhibit smooth muscle cell proliferation and platelet aggregation. The NO-sGC-cGMP pathway is disordered in pulmonary arterial hypertension (PAH), a syndrome in which pulmonary vascular obstruction, inflammation, thrombosis, and constriction ultimately lead to death from right heart failure. Expression of sGC is increased in PAH but its function is reduced by decreased NO bioavailability, sGC oxidation and the related loss of sGC's heme group. Two classes of sGC modulators offer promise in PAH. sGC stimulators (e.g., riociguat) require heme-containing sGC to catalyze cGMP production, whereas sGC activators (e.g., cinaciguat) activate heme-free sGC. Riociguat is approved for PAH and yields functional and hemodynamic benefits similar to other therapies. Its main serious adverse effect is dose-dependent hypotension. Riociguat is also approved for inoperable chronic thromboembolic pulmonary hypertension.

Topics: Animals; Benzoates; Chronic Disease; Cyclic GMP; Drug Design; Guanylate Cyclase; Humans; Hypertension, Pulmonary; Nitric Oxide; Pyrazoles; Pyrimidines; Receptors, Cytoplasmic and Nuclear; Soluble Guanylyl Cyclase; Thromboembolism

This review summarizes the role of soluble guanylate cyclase (sGC)-cyclic guanosine 3', 5'-monophosphate pathways in heart failure and several new drugs that modify guanylate cyclase. The sGC activators and stimulators as modulators of sGC are promising drugs in the therapy for decompensated heart failure and pulmonary hypertension. Cinaciguat is a nitric oxide (NO)-independent direct activator of sGC, which also may be effective under oxidative stress conditions resulting in oxidized or heme-free sGC refractory to organic nitrates. Riociguat is an NO-independent direct stimulator of sGC with beneficial effects in patients with decompensated heart failure and pulmonary hypertension. The sGC modulators play an important role in patients with heart failure and pulmonary hypertension.

Topics: Benzoates; Cardiovascular Agents; Guanylate Cyclase; Heart Failure; Humans; Hypertension, Pulmonary; Pyrazoles; Pyrimidines; Signal Transduction

The nitric oxide (NO)-soluble guanylate cyclase (sGC)-cyclic 3',5'-guanosine monophosphate (cGMP) pathway plays an important role in cardiovascular regulation by promoting vasodilation and inhibiting vascular smooth muscle cell growth, platelet aggregation, and leukocyte adhesion. In pathophysiological states with endothelial dysfunction this signaling pathway is impaired. Activation of sGC has traditionally been achieved with nitrovasodilators; however, these drugs are associated with the development of tolerance and potentially deleterious cGMP-independent actions. In this review the actions of BAY 41-2272, the prototype of a new class of NO-independent sGC stimulators, in cardiovascular disease models is discussed. BAY 41-2272 binds to a regulatory site on the alpha-subunit of sGC and stimulates the enzyme synergistically with NO. BAY 41-2272 had antihypertensive actions and attenuated remodeling in models of systemic arterial hypertension. It also unloaded the heart in experimental congestive heart failure. BAY 41-2272 reduced pulmonary vascular resistance in acute and chronic experimental pulmonary arterial hypertension. Furthermore, BAY 41-2272 inhibited platelet aggregation in vitro and leukocyte adhesion in vivo. These findings make direct sGC stimulation with BAY 41-2272 a promising new therapeutic strategy for cardiovascular diseases and warrant further studies. Finally, the significance of the novel NO- and heme-independent sGC activator BAY 58-2667, which activates two forms of NO-insensitive sGC, is briefly discussed.

Topics: Animals; Antihypertensive Agents; Benzoates; Cardiovascular Diseases; Cell Adhesion; Cyclic GMP; Disease Models, Animal; Endothelium, Vascular; Enzyme Activation; Enzyme Activators; Guanylate Cyclase; Heart Failure; Heme; Humans; Hypertension; Hypertension, Pulmonary; Inflammation; Leukocytes; Nitric Oxide; Platelet Aggregation; Pyrazoles; Pyridines; Receptors, Cytoplasmic and Nuclear; Soluble Guanylyl Cyclase; Vasodilator Agents

To investigate the mRNA expression level of plasminogen activator inhibitor-2 (PAI-2) in peripheral blood leucocytes and regulation by soluble guanylate cyclase (sGC) activator in pulmonary hypertension.. The human pulmonary arterial smooth muscle cells were treated with sGC activator Cinaciguat. The mRNA and protein expression levels of PAI-2 were detected with Real-time PCR and Western blot. The fresh blood samples of 8 patients with pulmonary arterial hypertension (PAH) (collected at the China-Japan Friendship Hospital from November 2014 to March 2015), 16 patients with chronic thromboembolic pulmonary hypertension (CTEPH) (collected at the China-Japan Friendship Hospital from November 2014 to March 2015), 24 age- and gender- matched healthy controls (collected at Beijing Hospital in March 2015) were treated with Cinaciguat for 8 hours. Then RNA of peripheral leukocytes was extracted and performed with reverse transcription and Real-time PCR to detect the mRNA level of PAI-2, which was compared between healthy controls and patients with pulmonary hypertension, before and after the treatment of Cinaciguat. At last, the correlation of PAI-2 mRNA level and the clinic severity of pulmonary hypertension were identified.. The mRNA and protein expression levels of PAI-2 were promoted by Cinaciguat in human pulmonary arterial smooth muscle cells. The baseline mRNA level of PAI-2 in peripheral leukocytes was significantly lower in PAH patients compared to the healthy controls (0.201±0.152, 0.660±0.440, P=0.021). There was no significant difference in the mRNA expression level of PAI-2 between the CTEPH patients and controls (0.428±0.364, 0.769±0.682, P=0.152). After Cinaciguat treatment, the mRNA expression levels of PAI-2 were up-regulated in PAH patients and CTEPH patients (1.352±1.127, 1.203±1.008), there was no significant difference in the mRNA expression level of PAI-2 among the PAH patients, CTEPH patients and controls (P=0.130, P=0.534). The baseline mRNA level of PAI-2 was negative correlated with echocardiography-estimated systolic pulmonary arterial pressure (sPAP) (r=-0.744, P=0.034).. The mRNA expression level of PAI-2 is significantly down-regulated in peripheral blood leucocytes and up-regulated by sGC activator in pulmonary hypertension. PAI-2 could be used as potential biomarker of pulmonary vascular remodeling in PAH.

Topics: Benzoates; Case-Control Studies; Cells, Cultured; Humans; Hypertension, Pulmonary; Leukocytes; Myocytes, Smooth Muscle; Plasminogen Activator Inhibitor 2; Pulmonary Artery; RNA, Messenger; Soluble Guanylyl Cyclase

Different types of pulmonary hypertension (PH) share the same process of pulmonary vascular remodeling, the molecular mechanism of which is not entirely clarified by far. The abnormal biological behaviors of pulmonary arterial smooth muscle cells (PASMCs) play an important role in this process.. We investigated the regulation of plasminogen activator inhibitor-2 (PAI-2) by the sGC activator, and explored the effect of PAI-2 on PASMCs proliferation, apoptosis and migration.. After the transfection with PAI-2 overexpression vector and specific siRNAs or treatment with BAY 41-2272 (an activator of sGC), the mRNA and protein levels of PAI-2 in cultured human PASMCs were detected, and the proliferation, apoptosis and migration of PASMCs were investigated.. BAY 41-2272 up regulated the endogenous PAI-2 in PASMCs, on the mRNA and protein level. In PAI-2 overexpression group, the proliferation and migration of PASMCs were inhibited significantly, and the apoptosis of PASMCs was increased. In contrast, PAI-2 knockdown with siRNA increased PASMCs proliferation and migration, inhibited the apoptosis.. PAI-2 overexpression inhibits the proliferation and migration and promotes the apoptosis of human PASMCs. Therefore, sGC activator might alleviate or reverse vascular remodeling in PH through the up-regulation of PAI-2.

Topics: Antihypertensive Agents; Apoptosis; Benzoates; Cell Movement; Cell Proliferation; Cells, Cultured; Enzyme Activators; Humans; Hypertension, Pulmonary; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Plasminogen Activator Inhibitor 2; Pulmonary Artery; Pyrazoles; Pyridines; Up-Regulation

Impaired nitric oxide-cGMP signaling contributes to severe pulmonary hypertension after birth, which may in part be due to decreased soluble guanylate cyclase (sGC) activity. Cinaciguat (BAY 58-2667) is a novel sGC activator that causes vasodilation, even in the presence of oxidized heme or heme-free sGC, but its hemodynamic effects have not been studied in the perinatal lung. We performed surgery on eight fetal (126 +/- 2 days gestation) lambs (full term = 147 days) and placed catheters in the main pulmonary artery, aorta, and left atrium to measure pressures. An ultrasonic flow transducer was placed on the left pulmonary artery to measure blood flow, and a catheter was placed in the left pulmonary artery for drug infusion. Cinaciguat (0.1-100 microg over 10 min) caused dose-related increases in pulmonary blood flow greater than fourfold above baseline and reduced pulmonary vascular resistance by 80%. Treatment with 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), an sGC-oxidizing inhibitor, enhanced cinaciguat-induced pulmonary vasodilation by >120%. The pulmonary vasodilator effect of cinaciguat was prolonged, decreasing pulmonary vascular resistance for >1.5 h after brief infusion. In vitro stimulation of ovine fetal pulmonary artery smooth muscle cells with cinaciguat after ODQ treatment resulted in a 14-fold increase in cGMP compared with non-ODQ-treated cells. We conclude that cinaciguat causes potent and sustained fetal pulmonary vasodilation that is augmented in the presence of oxidized sGC and speculate that cinaciguat may have therapeutic potential for severe neonatal pulmonary hypertension.

Topics: Acetylcholine; Animals; Animals, Newborn; Benzoates; Cells, Cultured; Cyclic GMP; Dose-Response Relationship, Drug; Enzyme Inhibitors; Female; Fetus; Gestational Age; Guanylate Cyclase; Hypertension, Pulmonary; Muscle, Smooth, Vascular; Nitric Oxide; Oxadiazoles; Pregnancy; Pulmonary Artery; Pulmonary Circulation; Pulmonary Wedge Pressure; Quinoxalines; Receptors, Cytoplasmic and Nuclear; Sheep; Soluble Guanylyl Cyclase; Vasodilation; Vasodilator Agents

Severe pulmonary hypertension is a disabling disease with high mortality, characterized by pulmonary vascular remodeling and right heart hypertrophy. Using wild-type and homozygous endothelial nitric oxide synthase (NOS3(-/-)) knockout mice with pulmonary hypertension induced by chronic hypoxia and rats with monocrotaline-induced pulmonary hypertension, we examined whether the soluble guanylate cyclase (sGC) stimulator Bay41-2272 or the sGC activator Bay58-2667 could reverse pulmonary vascular remodeling.. Both Bay41-2272 and Bay58-2667 dose-dependently inhibited the pressor response of acute hypoxia in the isolated perfused lung system. When wild-type (NOS3(+/+)) or NOS3(-/-) mice were housed under 10% oxygen conditions for 21 or 35 days, both strains developed pulmonary hypertension, right heart hypertrophy, and pulmonary vascular remodeling, demonstrated by an increase in fully muscularized peripheral pulmonary arteries. Treatment of wild-type mice with the activator of sGC, Bay58-2667 (10 mg/kg per day), or the stimulator of sGC, Bay41-2272 (10 mg/kg per day), after full establishment of pulmonary hypertension from day 21 to day 35 significantly reduced pulmonary hypertension, right ventricular hypertrophy, and structural remodeling of the lung vasculature. In contrast, only minor efficacy of chronic sGC activator therapies was noted in NOS3(-/-) mice. In monocrotaline-injected rats with established severe pulmonary hypertension, both compounds significantly reversed hemodynamic and structural changes.. Activation of sGC reverses hemodynamic and structural changes associated with monocrotaline- and chronic hypoxia-induced experimental pulmonary hypertension. This effect is partially dependent on endogenous nitric oxide generated by NOS3.

Topics: Animals; Benzoates; Cardiomegaly; Disease Models, Animal; Enzyme Activation; Guanylate Cyclase; Humans; Hypertension, Pulmonary; Hypertrophy, Right Ventricular; Hypoxia; Male; Mice; Mice, Knockout; Nitric Oxide Synthase Type II; Nitric Oxide Synthase Type III; Pulmonary Circulation; Pyrazoles; Pyridines; Rats; Rats, Sprague-Dawley; Solubility