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 cGMP modulation therapeutics for sickle cell disease

2019 ◽  
Vol 244 (2) ◽  
pp. 132-146 ◽  
Author(s):  
Nicola Conran ◽  
Lidiane Torres
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Guanylate Cyclase ◽  
Soluble Guanylate Cyclase ◽  
Cell Transplant ◽  
Cell Disease ◽  
Chronic Complications ◽  
Intracellular Cgmp ◽  
No Bioavailability ◽  
Sgc Stimulators

Sickle cell disease (SCD) is an inherited disease caused by the production of abnormal hemoglobin (Hb) S, whose deoxygenation-induced polymerization results in red blood cell (RBC) sickling and numerous pathophysiological consequences. SCD affects approximately 300,000 newborns worldwide each year and is associated with acute and chronic complications, including frequent painful vaso-occlusive episodes that often require hospitalization. Chronic intravascular hemolysis in SCD significantly reduces vascular nitric oxide (NO) bioavailability, consequently decreasing intracellular signaling via cyclic guanosine monophosphate (cGMP), in turn diminishing vasodilation and contributing to the inflammatory mechanisms that trigger vaso-occlusive processes. Oxidative stress may further reduce NO bioavailability in SCD and can oxidize the intracellular enzyme target of NO, soluble guanylate cyclase (sGC), rendering it inactive. Increasing intracellular cGMP-dependent signaling constitutes an important pharmacological therapeutic approach for SCD with a view to augmenting vasodilation, and reducing inflammatory mechanisms, as well as for increasing the production of anti-polymerizing fetal Hb in erythroid cells. Pharmacological agents under pre-clinical and clinical investigation for SCD include NO-based therapeutics to augment NO bioavailability, as well as heme-dependent sGC stimulators and heme-independent sGC activators that directly stimulate native and oxidized sGC, respectively, therefore bypassing the need for vascular NO delivery. Additionally, the phosphodiesterases (PDEs) that degrade intracellular cyclic nucleotides with specific cellular distributions are attractive drug targets for SCD; PDE9 is highly expressed in hematopoietic cells, making the use of PDE9 inhibitors, originally developed for use in neurological diseases, a potential approach that could rapidly amplify intracellular cGMP concentrations in a relatively tissue-specific manner. Impact statement Sickle cell disease (SCD) is one of the most common inherited diseases and is associated with a reduced life expectancy and acute and chronic complications, including frequent painful vaso-occlusive episodes that often require hospitalization. At present, treatment of SCD is limited to hematopoietic stem cell transplant, transfusion, and limited options for pharmacotherapy, based principally on hydroxyurea therapy. This review highlights the importance of intracellular cGMP-dependent signaling pathways in SCD pathophysiology; modulation of these pathways with soluble guanylate cyclase (sGC) stimulators or phosphodiesterase (PDE) inhibitors could potentially provide vasorelaxation and anti-inflammatory effects, as well as elevate levels of anti-sickling fetal hemoglobin.

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.

scholarly journals Reconstruction of Sickle Cell Disease with Circulating Sickling Red Blood Cells in Novel Humanized Cytokines and Liver Mistrg Mice

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 29-30
Author(s):  
Yuanbin Song ◽  
Rana Gbyli ◽  
Liang Shan ◽  
Wei Liu ◽  
Yimeng Gao ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Mouse Model ◽  
Red Blood Cells ◽  
Sickle Cell ◽  
Blood Cells ◽  
Red Cell ◽  
Cell Disease ◽  
Ineffective Erythropoiesis ◽  
Cd34 Cells

In vivo models of human erythropoiesis with generation of circulating mature human red blood cells (huRBC) have remained elusive, limiting studies of primary human red cell disorders. In our prior study, we have generated the first combined cytokine-liver humanized immunodeficient mouse model (huHepMISTRG-Fah) with fully mature, circulating huRBC when engrafted with human CD34+ hematopoietic stem and progenitor cells (HSPCs)1. Here we present for the first time a humanized mouse model of human sickle cell disease (SCD) which replicates the hallmark pathophysiologic finding of vaso-occlusion in mice engrafted with primary patient-derived SCD HSPCs. SCD is an inherited blood disorder caused by a single point mutation in the beta-globin gene. Murine models of SCD exclusively express human globins in mouse red blood cells in the background of murine globin knockouts2 which exclusively contain murine erythropoiesis and red cells and thus fail to capture the heterogeneity encountered in patients. To determine whether enhanced erythropoiesis and most importantly circulating huRBC in engrafted huHepMISTRG-Fah mice would be sufficient to replicate the pathophysiology of SCD, we engrafted it with adult SCD BM CD34+ cells as well as age-matched control BM CD34+ cells. Overall huCD45+ and erythroid engraftment in BM (Fig. a, b) and PB (Fig. c, d) were similar between control or SCD. Using multispectral imaging flow cytometry, we observed sickling huRBCs (7-11 sickling huRBCs/ 100 huRBCs) in the PB of SCD (Fig. e) but not in control CD34+ (Fig. f) engrafted mice. To determine whether circulating huRBC would result in vaso-occlusion and associated findings in SCD engrafted huHepMISTRG-Fah mice, we evaluated histological sections of lung, liver, spleen, and kidney from control and SCD CD34+ engrafted mice. SCD CD34+ engrafted mice lungs showed an increase in alveolar macrophages (arrowheads) associated with alveolar hemorrhage and thrombosis (arrows) but not observed control engrafted mice (Fig. g). Spleens of SCD engrafted mice showed erythroid precursor expansion, sickled erythrocytes in the sinusoids (arrowheads), and vascular occlusion and thrombosis (arrows) (Fig. h). Liver architecture was disrupted in SCD engrafted mice with RBCs in sinusoids and microvascular thromboses (Fig. i). Congestion of capillary loops and peritubular capillaries and glomeruli engorged with sickled RBCs was evident in kidneys (Fig. j) of SCD but not control CD34+ engrafted mice. SCD is characterized by ineffective erythropoiesis due to structural abnormalities in erythroid precursors3. As a functional structural unit, erythroblastic islands (EBIs) represent a specialized niche for erythropoiesis, where a central macrophage is surrounded by developing erythroblasts of varying differentiation states4. In our study, both SCD (Fig. k) and control (Fig. l) CD34+ engrafted mice exhibited EBIs with huCD169+ huCD14+ central macrophages surrounded by varying stages of huCD235a+ erythroid progenitors, including enucleated huRBCs (arrows). This implies that huHepMISTRG-Fah mice have the capability to generate human EBIs in vivo and thus represent a valuable tool to not only study the effects of mature RBC but also to elucidate mechanisms of ineffective erythropoiesis in SCD and other red cell disorders. In conclusion, we successfully engrafted adult SCD patient BM derived CD34+ cells in huHepMISTRG-Fah mice and detected circulating, sickling huRBCs in the mouse PB. We observed pathological changes in the lung, spleen, liver and kidney, which are comparable to what is seen in the established SCD mouse models and in patients. In addition, huHepMISTRG-Fah mice offer the opportunity to study the role of the central macrophage in human erythropoiesis in health and disease in an immunologically advantageous context. This novel mouse model could therefore serve to open novel avenues for therapeutic advances in SCD. Reference 1. Song Y, Shan L, Gybli R, et. al. In Vivo reconstruction of Human Erythropoiesis with Circulating Mature Human RBCs in Humanized Liver Mistrg Mice. Blood. 2019;134:338. 2. Ryan TM, Ciavatta DJ, Townes TM. Knockout-transgenic mouse model of sickle cell disease. Science. 1997;278(5339):873-876. 3. Blouin MJ, De Paepe ME, Trudel M. Altered hematopoiesis in murine sickle cell disease. Blood. 1999;94(4):1451-1459. 4. Manwani D, Bieker JJ. The erythroblastic island. Curr Top Dev Biol. 2008;82:23-53. Disclosures Xu: Seattle Genetics: Membership on an entity's Board of Directors or advisory committees. Flavell:Zai labs: Consultancy; GSK: Consultancy.

scholarly journals Gabapentin alleviates chronic spontaneous pain and acute hypoxia‐related pain in a mouse model of sickle cell disease

2019 ◽  
Vol 187 (2) ◽  
pp. 246-260
Author(s):  
Katelyn E. Sadler ◽  
Sarah N. Langer ◽  
Anthony D. Menzel ◽  
Francie Moehring ◽  
Ashley N. Erb ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Mouse Model ◽  
Sickle Cell ◽  
Acute Hypoxia ◽  
Spontaneous Pain ◽  
Cell Disease

Mechanisms of vascular instability in a transgenic mouse model of sickle cell disease

2000 ◽  
Vol 279 (6) ◽  
pp. R1949-R1955 ◽  
Author(s):  
K. A. Nath ◽  
V. Shah ◽  
J. J. Haggard ◽  
A. J. Croatt ◽  
L. A. Smith ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Lipid Peroxidation ◽  
Sickle Cell Disease ◽  
Mouse Model ◽  
Systolic Blood Pressure ◽  
Transgenic Mouse ◽  
Sickle Cell ◽  
Transgenic Mouse Model ◽  
Cell Disease

We investigated a transgenic mouse model of sickle cell disease, homozygous for deletion of mouse β-globin and containing transgenes for human βSand βS-antillesglobins linked to the transgene for human α-globin. In these mice, basal cGMP production in aortic rings is increased, whereas relaxation to an endothelium-dependent vasodilator, A-23187, is impaired. In contrast, aortic expression of endothelial nitric oxide synthase (NOS) is unaltered in sickle mice, whereas expression of inducible NOS is not detected in either group; plasma nitrate/nitrite concentrations and NOS activity are similar in both groups. Increased cGMP may reflect the stimulatory effect of peroxides (an activator of guanylate cyclase), because lipid peroxidation is increased in aortae and in plasma in sickle mice. Despite increased vascular cGMP levels in sickle mice, conscious systolic blood pressure is comparable to that of aged-matched controls; sickle mice, however, evince a greater rise in systolic blood pressure in response to nitro-l-arginine methyl ester, an inhibitor of NOS. Systemic concentrations of the vasoconstrictive oxidative product 8-isoprostane are increased in sickle mice. We conclude that vascular responses are altered in this transgenic sickle mouse and are accompanied by increased lipid peroxidation and production of cGMP; we suggest that oxidant-inducible vasoconstrictor systems such as isoprostanes may oppose nitric oxide-dependent and nitric oxide-independent mechanisms of vasodilatation in this transgenic sickle mouse. Destabilization of the vasoactive balance in the sickle vasculature by clinically relevant states may predispose to vasoocclusive disease.

scholarly journals Molecular steps in soluble guanylate cyclase activation

2005 ◽  
Vol 5 (Suppl 1) ◽  
pp. S1
Author(s):  
Elizabeth M Boon ◽  
Stephen PL Cary ◽  
Shirley H Huang ◽  
Jonathan A Winger ◽  
Michael A Marletta
Keyword(s):  
Guanylate Cyclase ◽  
Soluble Guanylate Cyclase ◽  
Cyclase Activation ◽  
Guanylate Cyclase Activation
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