The Experts below are selected from a list of 24 Experts worldwide ranked by ideXlab platform
Carlo Brugnara - One of the best experts on this subject based on the ideXlab platform.
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combined genetic disruption of k cl cotransporters and gardos channel kcnn4 rescues erythrocyte dehydration in the SAD Mouse model of sickle cell disease
Blood Cells Molecules and Diseases, 2019Co-Authors: Boris E Shmukler, Marie Trudel, Alicia Rivera, Parul Bhargava, Katherine Nishimura, Ann Hsu, Edward H Kim, Marco B Rust, Christian A Hubner, Carlo BrugnaraAbstract:Excessive red cell dehydration contributes to the pathophysiology of sickle cell disease (SCD). The densest fraction of sickle red cells (with the highest corpuscular hemoglobin concentration) undergoes the most rapid polymerization of deoxy-hemoglobin S, leading to accelerated cell sickling and increased susceptibility to endothelial activation, red cell adhesion, and vaso-occlusion. Increasing red cell volume in order to decrease red cell density can thus serve as an adjunct therapeutic goal in SCD. Regulation of circulating Mouse red cell volume and density is mediated largely by the Gardos channel, KCNN4, and the K-Cl cotransporters, KCC3 and KCC1. Whereas inhibition of the Gardos channel in subjects with sickle cell disease increased red cell volume, decreased red cell density, and improved other hematological indices in subjects with SCD, specific KCC inhibitors have not been available for testing. We therefore investigated the effect of genetic inactivation of KCC3 and KCC1 in the SAD Mouse model of sickle red cell dehydration, finding decreased red cell density and improved hematological indices. We describe here generation of mice genetically deficient in the three major red cell volume regulatory gene products, KCNN4, KCC3, and KCC1 in C57BL6 non-sickle and SAD sickle backgrounds. We show that combined loss-of-function of all three gene products in SAD mice leads to incrementally increased MCV, decreased CHCM and % hyperchromic cells, decreased red cell density (phthalate method), increased resistance to hypo-osmotic lysis, and increased cell K content. The data show that combined genetic deletion of the Gardos channel and K-Cl cotransporters in a Mouse SCD model decreases red cell density and improves several hematological parameters, supporting the strategy of combined pharmacological inhibition of these ion transport pathways in the adjunct treatment of human SCD.
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modulation of erythrocyte potassium chloride cotransport potassium content and density by dietary magnesium intake in transgenic SAD Mouse
Blood, 1996Co-Authors: L De Franceschi, Y Beuzard, H Jouault, Carlo BrugnaraAbstract:Prevention of erythrocyte dehydration is a potential therapeutic strategy for sickle cell disease. Increasing erythrocyte magnesium (Mg) could inhibit sickle cell dehydration by increasing chloride (CI) and water content and by inhibiting potassium chloride (K-CI) cotransport. In transgenic SAD 1 and (control) C57BL/6 normal mice, we investigated the effect of 2 weeks of diet with either low Mg (6 +/- 2 mg/kg body weight/d) or high Mg (1,000 +/- 20 mg/kg body weight/ d), in comparison with a diet of standard Mg (400 +/- 20 mg/ kg body weight/d). The high-Mg diet increased SAD 1 erythrocyte Mg and K contents and reduced K-CI cotransport activity, mean corpuscular hemoglobin concentration (MCHC), cell density, and reticulocyte count. SAD 1 mice treated with low-Mg diet showed a significant reduction in erythrocyte Mg and K contents and increases in K-CI cotransport, MCHC, cell density, and reticulocyte counts. In SAD 1 mice, hematocrit (Hct) and hemoglobin (Hb) decreased significantly with low Mg diet and increased significantly with high-Mg diet. The C57BL/6 controls showed significant changes only in erythrocyte Mg and K content, and K-CI cotransport activities, similar to those observed in SAD 1 mice. Thus, in the SAD 1 Mouse, changes in dietary Mg modulate K-CI cotransport, modify erythrocyte dehydration, and ultimately affect Hb levels.
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sulfhydryl oxidation and activation of red cell k cl cotransport in the transgenic SAD Mouse
American Journal of Physiology-cell Physiology, 1995Co-Authors: L De Franceschi, Y Beuzard, Carlo BrugnaraAbstract:The SAD Mouse is characterized by the expression of human SAD hemoglobin (Hb), a super S Hb with a higher tendency to polymerize than HbS due to the presence of two additional mutations, Antilles beta 23Ile and D Punjab beta 121Glu. Monovalent cation transport was studied in erythrocytes from SAD-1 (Hb SAD = 19%) and beta-thal/SAD-1 (Hb SAD = 26%) mice. Erythrocytes containing Hb SAD exhibited dehydration, increased maximal rate of Na(+)-K+ pump, unchanged Rb+ flux via the Gardos channel, and increased K(+)-Cl- cotransport. K(+)-Cl- cotransport was defined as Cl(-)-dependent (substitution with sulfamate or methanesulfonate) okadaic acid-sensitive K+ efflux. Volume regulatory decrease via K(+)-Cl- cotransport was also increased in swollen SAD erythrocytes compared with controls. K(+)-Cl- cotransport was stimulated by staurosporine in all Mouse strains, but the extent of stimulation was reduced in beta-thal/SAD-1 mice. Treatment with dithiothreitol reduced K(+)-Cl- cotransport activity in SAD-1 and beta-thal/SAD-1 mice to levels similar to that of control strains, indicating that reversible sulfhydryl oxidation contributes to the activated state of K(+)-Cl- cotransport in Mouse erythrocytes that express transgenic human Hb SAD.
Marie Trudel - One of the best experts on this subject based on the ideXlab platform.
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combined genetic disruption of k cl cotransporters and gardos channel kcnn4 rescues erythrocyte dehydration in the SAD Mouse model of sickle cell disease
Blood Cells Molecules and Diseases, 2019Co-Authors: Boris E Shmukler, Marie Trudel, Alicia Rivera, Parul Bhargava, Katherine Nishimura, Ann Hsu, Edward H Kim, Marco B Rust, Christian A Hubner, Carlo BrugnaraAbstract:Excessive red cell dehydration contributes to the pathophysiology of sickle cell disease (SCD). The densest fraction of sickle red cells (with the highest corpuscular hemoglobin concentration) undergoes the most rapid polymerization of deoxy-hemoglobin S, leading to accelerated cell sickling and increased susceptibility to endothelial activation, red cell adhesion, and vaso-occlusion. Increasing red cell volume in order to decrease red cell density can thus serve as an adjunct therapeutic goal in SCD. Regulation of circulating Mouse red cell volume and density is mediated largely by the Gardos channel, KCNN4, and the K-Cl cotransporters, KCC3 and KCC1. Whereas inhibition of the Gardos channel in subjects with sickle cell disease increased red cell volume, decreased red cell density, and improved other hematological indices in subjects with SCD, specific KCC inhibitors have not been available for testing. We therefore investigated the effect of genetic inactivation of KCC3 and KCC1 in the SAD Mouse model of sickle red cell dehydration, finding decreased red cell density and improved hematological indices. We describe here generation of mice genetically deficient in the three major red cell volume regulatory gene products, KCNN4, KCC3, and KCC1 in C57BL6 non-sickle and SAD sickle backgrounds. We show that combined loss-of-function of all three gene products in SAD mice leads to incrementally increased MCV, decreased CHCM and % hyperchromic cells, decreased red cell density (phthalate method), increased resistance to hypo-osmotic lysis, and increased cell K content. The data show that combined genetic deletion of the Gardos channel and K-Cl cotransporters in a Mouse SCD model decreases red cell density and improves several hematological parameters, supporting the strategy of combined pharmacological inhibition of these ion transport pathways in the adjunct treatment of human SCD.
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the transgenic SAD Mouse a model of human sickle cell glomerulopathy
Kidney International, 1994Co-Authors: Monique E De Paepe, Marie TrudelAbstract:The transgenic SAD Mouse: A model of human sickle cell glomerulopathy. The transgenic SAD Mouse which expresses a modified sickle hemoglobin, Hb SAD, displays in vivo hemoglobin polymerization and erythrocyte sickling. In the present study functional and morphological renal analyses were performed in SAD mice in order to compare the renal pathology of SAD mice with the human disease. The SAD mice display renal hemosiderosis, microvascular occlusions, vascular thrombosis, cortical infarcts and papillary necrosis. In the medulla, hemoglobin polymers could be observed with infrequent erythrocyte sickling, which may explain the absence of significant renal concentration defect, whereas in humans, the difference in the vascularization network leads to more extensive sickling. Most animals develop glomerular hypertrophy and mesangial sclerosis which increases in frequency and severity with age. The glomerular damage is associated with functional defects, including increased blood urea nitrogen levels and non-selective proteinuria. The glomerular lesions of SAD mice strikingly mimick sickle cell glomerulosclerosis, the most severe renal complication of sickle cell disease in humans. In summary, the SAD Mouse is a valuable model of the thrombotic and glomerulosclerotic complications of human sickle cell glomerulopathy and can serve for pathophysiologic studies, and, eventually, for prevention and therapy investigation.
L De Franceschi - One of the best experts on this subject based on the ideXlab platform.
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modulation of erythrocyte potassium chloride cotransport potassium content and density by dietary magnesium intake in transgenic SAD Mouse
Blood, 1996Co-Authors: L De Franceschi, Y Beuzard, H Jouault, Carlo BrugnaraAbstract:Prevention of erythrocyte dehydration is a potential therapeutic strategy for sickle cell disease. Increasing erythrocyte magnesium (Mg) could inhibit sickle cell dehydration by increasing chloride (CI) and water content and by inhibiting potassium chloride (K-CI) cotransport. In transgenic SAD 1 and (control) C57BL/6 normal mice, we investigated the effect of 2 weeks of diet with either low Mg (6 +/- 2 mg/kg body weight/d) or high Mg (1,000 +/- 20 mg/kg body weight/ d), in comparison with a diet of standard Mg (400 +/- 20 mg/ kg body weight/d). The high-Mg diet increased SAD 1 erythrocyte Mg and K contents and reduced K-CI cotransport activity, mean corpuscular hemoglobin concentration (MCHC), cell density, and reticulocyte count. SAD 1 mice treated with low-Mg diet showed a significant reduction in erythrocyte Mg and K contents and increases in K-CI cotransport, MCHC, cell density, and reticulocyte counts. In SAD 1 mice, hematocrit (Hct) and hemoglobin (Hb) decreased significantly with low Mg diet and increased significantly with high-Mg diet. The C57BL/6 controls showed significant changes only in erythrocyte Mg and K content, and K-CI cotransport activities, similar to those observed in SAD 1 mice. Thus, in the SAD 1 Mouse, changes in dietary Mg modulate K-CI cotransport, modify erythrocyte dehydration, and ultimately affect Hb levels.
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sulfhydryl oxidation and activation of red cell k cl cotransport in the transgenic SAD Mouse
American Journal of Physiology-cell Physiology, 1995Co-Authors: L De Franceschi, Y Beuzard, Carlo BrugnaraAbstract:The SAD Mouse is characterized by the expression of human SAD hemoglobin (Hb), a super S Hb with a higher tendency to polymerize than HbS due to the presence of two additional mutations, Antilles beta 23Ile and D Punjab beta 121Glu. Monovalent cation transport was studied in erythrocytes from SAD-1 (Hb SAD = 19%) and beta-thal/SAD-1 (Hb SAD = 26%) mice. Erythrocytes containing Hb SAD exhibited dehydration, increased maximal rate of Na(+)-K+ pump, unchanged Rb+ flux via the Gardos channel, and increased K(+)-Cl- cotransport. K(+)-Cl- cotransport was defined as Cl(-)-dependent (substitution with sulfamate or methanesulfonate) okadaic acid-sensitive K+ efflux. Volume regulatory decrease via K(+)-Cl- cotransport was also increased in swollen SAD erythrocytes compared with controls. K(+)-Cl- cotransport was stimulated by staurosporine in all Mouse strains, but the extent of stimulation was reduced in beta-thal/SAD-1 mice. Treatment with dithiothreitol reduced K(+)-Cl- cotransport activity in SAD-1 and beta-thal/SAD-1 mice to levels similar to that of control strains, indicating that reversible sulfhydryl oxidation contributes to the activated state of K(+)-Cl- cotransport in Mouse erythrocytes that express transgenic human Hb SAD.
Jeanpierre Cartron - One of the best experts on this subject based on the ideXlab platform.
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intercellular adhesion molecule 4 and cd36 are implicated in the abnormal adhesiveness of sickle cell SAD Mouse erythrocytes to endothelium
Haematologica, 2010Co-Authors: Mariemarcelle Trinhtrangtan, Camilo Vilelalamego, Julien Picot, Mariepaule Wautier, Jeanpierre CartronAbstract:Background Abnormal adhesiveness of red blood cells to endothelium has been implicated in vaso-occlusive crisis of sickle cell disease. The present study examined whether the SAD Mouse model exhibits the same abnormalities of red blood cell adhesion as those found in human sickle cell disease.Design and Methods The repertoire of adhesive molecules on murine erythrocytes and bEnd.3 microvascular endothelial cells was determined by flow cytometry using monoclonal antibodies or by western blotting. Adhesion was investigated in dynamic conditions and measured at different shear stresses.Results CD36, CD47 and intercellular adhesion molecular-4, but not Lutheran blood group antigen/basal cell adhesion molecule, are present on Mouse mature erythrocytes. α4β1 are not expressed on SAD and wild type reticulocytes. Endothelial bEnd.3 cells express αVβ3, α4β1, CD47, vascular cell adhesion molecule-1, and Lutheran blood group antigen/basal cell adhesion molecule, but not CD36. Adhesion of SAD red cells is: (i) 2- to 3-fold higher than that of wild type red cells; (ii) further increased on platelet activating factor-activated endothelium; (iii) not stimulated by epinephrine; (iv) inhibited after treating the endothelium with a peptide reproducing one of the binding sequences of Mouse intercellular adhesion molecular-4, or with mon-oclonal antibody against murine αv integrin; and (v) inhibited after pretreatment of red blood cells with anti-Mouse CD36 monoclonal antibodies. The combination of treatments with intercellular adhesion molecular-4 peptide and anti-CD36 monoclonal antibodies eliminates excess adhesion of SAD red cells. The phosphorylation state of intercellular adhesion molecular-4 and CD36 is probably not involved in the over-adhesiveness of SAD erythrocytes.Conclusions Intercellular adhesion molecular-4/αvβ3 and CD36/thrombospondin interactions might contribute to the abnormally high adhesiveness of SAD red cells. The SAD Mouse is a valuable animal model for investigating adhesion processes of sickle cell disease.
Bernard Maitre - One of the best experts on this subject based on the ideXlab platform.
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new nitric oxide donor ncx 1443 therapeutic effects on pulmonary hypertension in the SAD Mouse model of sickle cell disease
Journal of Cardiovascular Pharmacology, 2018Co-Authors: Shariq Abid, Kanny Kebe, Amal Houssaini, Francoise Tomberli, Elisabeth Marcos, Emilie Bizard, Marielle Breau, Aurelien Parpaleix, Clairemarie Tissot, Bernard MaitreAbstract:Abstract:Nitric oxide (NO) donors may be useful for treating pulmonary hypertension (PH) complicating sickle cell disease (SCD), as endogenous NO is inactivated by hemoglobin released by intravascular hemolysis. Here, we investigated the effects of the new NO donor NCX1443 on PH in transgenic SAD mi
