Antisickling Effects of Quercetin may be Associated with Modulation of Deoxyhaemoglobin, 2, 3-bisphosphoglycerate mutase, Redox Homeostasis and Alteration of Functional Chemistry in Human Sickle Erythrocytes.

AbstractIt is now glaring that sickle cell anaemia is still one of the highest leading inbred hemoglobinopathy amongst Africans. This study examined the antisickling effects of quercetin via modulation of deoxy-haemoglobin, redox homeostasis and alteration of functional chemistry in human sickle erythrocyte using in silico and in vitro models while espousing preventive and curative approaches. Quercetin was docked against deoxy-haemoglobin and 2, 3-bisphosphoglycerate mutase, with binding energies (−30.427 and −21.106 kcal/mol) and Ki of 0.988μM and 0.992μM at their catalytic sites via strong hydrophobic and hydrogen bond interactions. Induction of sickling was done using 2% metabisulphite at 3h. Treatment with quercetin prevented sickling outstandingly at 5.0μg/mL and reversed same at 7.5μg/mL, 83.6% and 75.9%, respectively. Quercetin also significantly (P<0.05) maintained the integrity of erythrocyte membrane apparently from the observed % haemolysis relative to untreated. Quercetin significantly (P<0.05) prevented and counteracted lipid peroxidation while stimulating GSH and CAT levels which were detected to considerably (P<0.05) increase with simultaneous significant (P<0.05) reduction in SOD level based on curative approach. Umpiring from our FTIR results, a favorable alteration in the part of functional chemistry in terms of shifts (bend and stretches) and functional groups were observed relative to the induced erythrocyte/untreated. Thus, antisickling effects of quercetin may be associated with modulation of deoxy-haemoglobin, redox homeostasis and alteration of functional chemistry in human sickle erythrocytes.

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Sickling-suppressive effects of chrysin may be associated with sequestration of deoxy-haemoglobin, 2,3-bisphosphoglycerate mutase, alteration of redox homeostasis and functional chemistry of sickle erythrocytes

Human & Experimental Toxicology ◽

10.1177/0960327119895815 ◽

2019 ◽

Vol 39 (4) ◽

pp. 537-546 ◽

Cited By ~ 1

Author(s):

A Muhammad ◽

AD Waziri ◽

GE Forcados ◽

B Sanusi ◽

H Sani ◽

...

Keyword(s):

Active Sites ◽

Medical Condition ◽

Globin Gene ◽

Redox Homeostasis ◽

Binding Energies ◽

Sub Saharan Africa ◽

Hydrogen Bond Interactions ◽

Sickle Erythrocytes ◽

Bisphosphoglycerate Mutase

Sickle cell disease (SCD) is a medical condition caused by mutation in a single nucleotide in the β-globin gene. It is a health problem for people in sub-Saharan Africa, the Middle East and India. Orthodox drugs developed so far for SCD focus largely on symptomatic respite of pain and crisis mitigation. We investigated the antisickling effects of chrysin via modulation of deoxy-haemoglobin, 2,3-bisphosphoglycerate mutase, redox homeostasis and alteration of functional chemistry in human sickle erythrocytes. In silico and in vitro methods were adopted for the studies. Chrysin was docked against deoxy-haemoglobin and 2,3-bisphosphoglycerate mutase, with binding energies (−24.064 and −18.171 kcal/mol) and inhibition constant ( K i) of 0.990 µM and 0.993 µM at their active sites through strong hydrophobic and hydrogen bond interactions. Sickling was induced with 2% metabisulphite at 3 h. Chrysin was able to prevent sickling maximally at 2.5 µg/mL and reversed the same at 12.5 µg/mL, by 66.5% and 69.6%, respectively. Treatment with chrysin significantly ( p < 0.05) re-established the integrity of erythrocytes membrane as evident from the observed percentage of haemolysis relative to induced erythrocytes. Chrysin also significantly ( p < 0.05) prevented and reversed lipid peroxidation. Similarly, glutathione and catalase levels were observed to significantly ( p < 0.05) increase with concomitant significant ( p < 0.05) decrease in superoxide dismutase activity relative to untreated. From Fourier-transform infrared results, treatment with chrysin was able to favourably alter the functional chemistry, judging from the shifts and functional groups observed. Sickling-suppressive effects of chrysin may therefore be associated with sequestration of deoxy-haemoglobin, 2,3-bisphosphoglycerate mutase, alteration of redox homeostasis and functional chemistry of sickle erythrocytes.

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Antiproliferative Benzoindazolequinones as Potential Cyclooxygenase-2 Inhibitors

Molecules ◽

10.3390/molecules24122261 ◽

2019 ◽

Vol 24 (12) ◽

pp. 2261 ◽

Cited By ~ 1

Author(s):

Aurora Molinari ◽

Alfonso Oliva ◽

Marlene Arismendi-Macuer ◽

Leda Guzmán ◽

Waldo Acevedo ◽

...

Keyword(s):

Cell Lines ◽

In Silico ◽

Antitumor Agents ◽

Human Cancer ◽

In Vitro Models ◽

Cyclooxygenase 2 ◽

Binding Energies ◽

Human Cancer Cells ◽

Mcf 7

Quinones and nitrogen heterocyclic moieties have been recognized as important pharmacophores in the development of antitumor agents. This study aimed to establish whether there was any correlation between the in silico predicted parameters and the in vitro antiproliferative activity of a family of benzoindazolequinones (BIZQs), and to evaluate overexpressed proteins in human cancer cells as potential biomolecular targets of these compounds. For this purpose, this study was carried out using KATO-III and MCF-7 cell lines as in vitro models. Docking results showed that these BIZQs present better binding energies (ΔGbin) values for cyclooxygenase-2 (COX-2) than for other cancer-related proteins. The predicted ∆Gbin values of these BIZQs, classified in three series, positively correlated with IC50 measured in both cell lines (KATO-III: 0.72, 0.41, and 0.90; MCF-7: 0.79, 0.55, and 0.87 for Series I, II, and III, respectively). The results also indicated that compounds 2a, 2c, 6g, and 6k are the most prominent BIZQs, because they showed better IC50 and ∆Gbin values than the other derivatives. In silico drug absorption, distribution, metabolism, and excretion (ADME) properties of the three series were also analyzed and showed that several BIZQs could be selected as potential candidates for cancer pre-clinical assays.

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Protein Disulfide Isomerase Regulates Sickle Erythrocyte Volume Via ET-1 Dependent Casein Kinase II Mechanism

Blood ◽

10.1182/blood.v118.21.2114.2114 ◽

2011 ◽

Vol 118 (21) ◽

pp. 2114-2114

Author(s):

Shirley D Valentin-Berrios ◽

Jose R Romero ◽

Alicia Rivera

Keyword(s):

Plasma Membrane ◽

Sickle Cell ◽

Protein Disulfide Isomerase ◽

Disulfide Isomerase ◽

Sickle Erythrocyte ◽

Cellular Dehydration ◽

Sickle Erythrocytes ◽

Protein Disulfide

Abstract Abstract 2114 Disordered K+ efflux and osmotically induced water loss leads to red blood cell (RBC) dehydration and plays a role in the pathophysiology of Sickle Cell Disease. We previously reported that activation of endothelin-1 (ET-1) receptors in sickle erythrocyte was partially responsible for dense sickle cell formation. However, the mechanism by which ET-1 regulates RBC volume remains unclear. Serine/threonine kinases have been shown to regulate K+ transport in RBC. Casein Kinase II (CK2), a serine/threonine kinase, phosphorylates acidic proteins, regulates calmodulin activity and cytoskeletal proteins and is present in RBC. CK2 activity is blocked by apigenin, emodin, heparin, and ornithine decarboxylase. Previous reports have shown a role for flavonoids such as apigenin as substrates for erythrocyte plasma membrane oxidoreductases. We recently observed a role for Protein Disulfide Isomerase (PDI) in regulating cellular hydration and K+ efflux in human RBC. PDI catalyzes disulfide interchange reactions in the plasma membrane, mediates redox modifications and is up-regulated under hypoxic conditions. However the relationship between CK2 and PDI in the setting of cellular hydration status is un-explored. Our results indicate that erythrocyte membrane CK2 activity increases when sickle cells are incubated with 500 nM ET-1 for 30 min (2.8 ± 0.1 to 4.9 ± 0.01 nmol/min/mL * 106 cell) an event that is blunted by pre-incubation with the ET-1 B receptor blocker, BQ788 (2.5 ± 0.1 nmol/min/mL * 106 cell, n=3, p<0.04) and 20 μM apigenin (2.7 ± 0.4 nmol/min/mL * 106 cell, n=3, p<0.04). We examined the role of CK2 activation on cellular dehydration. We incubated sickle erythrocytes for 3 hours in deoxygenation-oxygenation cycles in the presence or absence of 20μM apigenin or 2μM 4,5,6,7-tetrabromobenzotriazole (TBB), a specific CK2 inhibitor, and measured the changes in erythrocyte density by phthalate oil density analysis. We observed that inhibition of CK2 led to reduced deoxygenation-stimulated cellular dehydration in sickle erythrocytes by apigenin (D50= 1.106 to 1.100 g/mL) or TBB (D50 =1.097 g/mL). We then studied the role of CK2 inhibitors on PDI activity by Insulin Turbidity Assay and observed that apigenin and TBB led to significant reductions in PDI activity in vitro (64% and 42% respectively). We also studied the effects of the flavonoids: naringenin, naringin, apigenin and rutin on PDI activity and observed reductions in PDI activity that were greater with apigenin>rutin>TBB>naringin>naringenin (n=2, P<0.05). Furthermore, we observed that K+ flux via Gardos channel activation is correlated with PDI activity in vitro in sickle erythrocytes. Taken together our results implicate CK2 and PDI as intermediate regulators of ET-1 stimulated cellular volume systems in red blood cells. Supported by NIH R01-HL09632 to AR. Disclosures: No relevant conflicts of interest to declare.

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Sickle Cell Acute Chest Syndrome: Pathogenesis and Rationale for Treatment

Blood ◽

10.1182/blood.v94.5.1555.417k36_1555_1560 ◽

1999 ◽

Vol 94 (5) ◽

pp. 1555-1560 ◽

Cited By ~ 6

Author(s):

Marie J. Stuart ◽

B.N. Yamaja Setty

Keyword(s):

Steady State ◽

Sickle Cell ◽

Adhesion Molecule ◽

Inhibitory Effect ◽

Acute Chest Syndrome ◽

Endothelial Adhesion Molecule ◽

Sickle Erythrocyte ◽

Sickle Erythrocytes ◽

Cell Adhesion Molecule 1

Acute chest syndrome (ACS) is a leading cause of death in sickle cell disease (SCD). Our previous work showed that hypoxia enhances the ability of sickle erythrocytes to adhere to human microvessel endothelium via interaction between very late activation antigen-4 (VLA4) expressed on sickle erythrocytes and the endothelial adhesion molecule vascular cell adhesion molecule-1 (VCAM-1). Additionally, hypoxia has been shown to decrease the production of nitric oxide (NO) which inhibits VCAM-1 upregulation. Based on these observations, we hypothesize that during ACS, the rapidly progressive clinical course that can occur is caused by initial hypoxia-induced pulmonary endothelial VCAM-1 upregulation that is not counterbalanced by production of cytoprotective mediators, including NO, resulting in intrapulmonary adhesion. We assessed plasma NO metabolites and soluble VCAM-1 in 36 patients with SCD and 23 age-matched controls. Patients with SCD were evaluated at baseline (n = 36), in vaso-occlusive crisis (VOC; n = 12), and during ACS (n = 7). We observed marked upregulation of VCAM-1 during ACS (1,290 ± 451 ng per mL; mean ± 1 SD) with values significantly higher than controls (P < .0001) or patients either in steady state or VOC (P < .01). NO metabolites were concomitantly decreased during ACS (9.2 ± 1.5 nmol/mL) with values lower than controls (22.2 ± 5.5), patients during steady state (21.4 ± 5.5), or VOC (14.2 ± 1.2) (P< .0001). Additionally, the ratio of soluble VCAM-1 to NO metabolites during ACS (132.9 ± 46.5) was significantly higher when compared with controls (P < .0001) or patients either in steady state or VOC (P < .0001). Although hypoxia enhanced in vitro sickle erythrocyte-pulmonary microvessel adhesion, NO donors inhibited this process with concomitant inhibition of VCAM-1. We suggest that in ACS there is pathologic over expression of endothelial VCAM-1. Our investigations also provide a rationale for the therapeutic use in ACS of cytoprotective modulators including NO and dexamethasone, which potentially exert their efficacy by an inhibitory effect on VCAM-1 and concomitant inhibition of sickle erythrocyte-endothelial adhesion.

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The Role of Cystinosin in the Intermediary Thiol Metabolism and Redox Homeostasis in Kidney Proximal Tubular Cells

Antioxidants ◽

10.3390/antiox7120179 ◽

2018 ◽

Vol 7 (12) ◽

pp. 179 ◽

Cited By ~ 4

Author(s):

Rodolfo Sumayao ◽

Philip Newsholme ◽

Tara McMorrow

Keyword(s):

Redox Homeostasis ◽

In Vitro Models ◽

Cellular Redox ◽

Tubular Cells ◽

Thiol Metabolism ◽

Proximal Tubular ◽

Kidney Proximal Tubular Cells

Cystinosin is a lysosomal transmembrane protein which facilitates transport of the disulphide amino acid cystine (CySS) from the lysosomes of the cell. This protein is encoded by the CTNS gene which is defective in the lysosomal storage disorder, cystinosis. Because of the apparent involvement of cystinosin in the intermediary thiol metabolism, its discovery has fuelled investigations into its role in modulating cellular redox homeostasis. The kidney proximal tubular cells (PTCs) have become the focus of various studies on cystinosin since the protein is highly expressed in these cells and kidney proximal tubular transport dysfunction is the foremost clinical manifestation of cystinosis. The lysosomal CySS pool is a major source of cytosolic cysteine (Cys), the limiting amino acid for the synthesis of an important antioxidant glutathione (GSH) via the γ-glutamyl cycle. Therefore, loss of cystinosin function is presumed to lead to cytosolic deficit of Cys which may impair GSH synthesis. However, studies using in vitro models lacking cystinosin yielded inconsistent results and failed to establish the mechanistic role of cystinosin in modulating GSH synthesis and redox homeostasis. Because of the complexity of the metabolic micro- and macro-environment in vivo, using in vitro models alone may not be able to capture the complete sequence of biochemical and physiological events that occur as a consequence of loss of cystinosin function. The coexistence of pathways for the overall handling and disposition of GSH, the modulation of CTNS gene by intracellular redox status and the existence of a non-canonical isoform of cystinosin may constitute possible rescue mechanisms in vivo to remediate redox perturbations in renal PTCs. Importantly, the mitochondria seem to play a critical role in orchestrating redox imbalances initiated by cystinosin dysfunction. Non-invasive techniques such as in vivo magnetic resonance imaging with the aid of systems biology approaches may provide invaluable mechanistic insights into the role of cystinosin in the essential intermediary thiol metabolism and in the overall regulation cellular redox homeostasis.

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Sickle Cell Acute Chest Syndrome: Pathogenesis and Rationale for Treatment

Blood ◽

10.1182/blood.v94.5.1555 ◽

1999 ◽

Vol 94 (5) ◽

pp. 1555-1560 ◽

Cited By ~ 101

Author(s):

Marie J. Stuart ◽

B.N. Yamaja Setty

Keyword(s):

Steady State ◽

Sickle Cell ◽

Adhesion Molecule ◽

Inhibitory Effect ◽

Acute Chest Syndrome ◽

Endothelial Adhesion Molecule ◽

Sickle Erythrocyte ◽

Sickle Erythrocytes ◽

Cell Adhesion Molecule 1

Abstract Acute chest syndrome (ACS) is a leading cause of death in sickle cell disease (SCD). Our previous work showed that hypoxia enhances the ability of sickle erythrocytes to adhere to human microvessel endothelium via interaction between very late activation antigen-4 (VLA4) expressed on sickle erythrocytes and the endothelial adhesion molecule vascular cell adhesion molecule-1 (VCAM-1). Additionally, hypoxia has been shown to decrease the production of nitric oxide (NO) which inhibits VCAM-1 upregulation. Based on these observations, we hypothesize that during ACS, the rapidly progressive clinical course that can occur is caused by initial hypoxia-induced pulmonary endothelial VCAM-1 upregulation that is not counterbalanced by production of cytoprotective mediators, including NO, resulting in intrapulmonary adhesion. We assessed plasma NO metabolites and soluble VCAM-1 in 36 patients with SCD and 23 age-matched controls. Patients with SCD were evaluated at baseline (n = 36), in vaso-occlusive crisis (VOC; n = 12), and during ACS (n = 7). We observed marked upregulation of VCAM-1 during ACS (1,290 ± 451 ng per mL; mean ± 1 SD) with values significantly higher than controls (P < .0001) or patients either in steady state or VOC (P < .01). NO metabolites were concomitantly decreased during ACS (9.2 ± 1.5 nmol/mL) with values lower than controls (22.2 ± 5.5), patients during steady state (21.4 ± 5.5), or VOC (14.2 ± 1.2) (P< .0001). Additionally, the ratio of soluble VCAM-1 to NO metabolites during ACS (132.9 ± 46.5) was significantly higher when compared with controls (P < .0001) or patients either in steady state or VOC (P < .0001). Although hypoxia enhanced in vitro sickle erythrocyte-pulmonary microvessel adhesion, NO donors inhibited this process with concomitant inhibition of VCAM-1. We suggest that in ACS there is pathologic over expression of endothelial VCAM-1. Our investigations also provide a rationale for the therapeutic use in ACS of cytoprotective modulators including NO and dexamethasone, which potentially exert their efficacy by an inhibitory effect on VCAM-1 and concomitant inhibition of sickle erythrocyte-endothelial adhesion.

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