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Kuczynski CE, Porada CD, Atala A, Cho SS, Almeida-Porada G. Evaluating sheep hemoglobins with MD simulations as an animal model for sickle cell disease. Sci Rep 2024; 14:276. [PMID: 38168584 PMCID: PMC10761887 DOI: 10.1038/s41598-023-50707-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 12/23/2023] [Indexed: 01/05/2024] Open
Abstract
Sickle cell disease (SCD) affects millions worldwide, yet there are few therapeutic options. To develop effective treatments, preclinical models that recapitulate human physiology and SCD pathophysiology are needed. SCD arises from a single Glu-to-Val substitution at position 6 in the β subunit of hemoglobin (Hb), promoting Hb polymerization and subsequent disease. Sheep share important physiological and developmental characteristics with humans, including the same developmental pattern of fetal to adult Hb switching. Herein, we investigated whether introducing the SCD mutation into the sheep β-globin locus would recapitulate SCD's complex pathophysiology by generating high quality SWISS-MODEL sheep Hb structures and performing MD simulations of normal/sickle human (huHbA/huHbS) and sheep (shHbB/shHbS) Hb, establishing how accurately shHbS mimics huHbS behavior. shHbS, like huHbS, remained stable with low RMSD, while huHbA and shHbB had higher and fluctuating RMSD. shHbB and shHbS also behaved identically to huHbA and huHbS with respect to β2-Glu6 and β1-Asp73 (β1-Asn72 in sheep) solvent interactions. These data demonstrate that introducing the single SCD-causing Glu-to-Val substitution into sheep β-globin causes alterations consistent with the Hb polymerization that drives RBC sickling, supporting the development of a SCD sheep model to pave the way for alternative cures for this debilitating, globally impactful disease.
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Affiliation(s)
| | | | - Anthony Atala
- Wake Forest Institute for Regenerative Medicine, Winston-Salem, NC, 27101, USA
| | - Samuel S Cho
- Department of Physics, Wake Forest University, Winston-Salem, NC, 27109, USA.
- Department of Computer Science, Wake Forest University, Winston-Salem, NC, 27109, USA.
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Omar AM, Abdulmalik O, El-Say KM, Ghatge MS, Cyril-Olutayo M, Paredes S, Al-Awadh M, El-Araby ME, Safo MK. Targeted modification of furan-2-carboxaldehydes into Michael acceptor analogs yielded long-acting hemoglobin modulators with dual antisickling activities. Chem Biol Drug Des 2024; 103:e14371. [PMID: 37798397 DOI: 10.1111/cbdd.14371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 09/10/2023] [Accepted: 09/26/2023] [Indexed: 10/07/2023]
Abstract
Sickle cell disease (SCD) is the most common genetic disorder, affecting millions of people worldwide. Aromatic aldehydes, which increase the oxygen affinity of human hemoglobin to prevent polymerization of sickle hemoglobin and inhibit red blood cell (RBC) sickling, have been the subject of keen interest for the development of effective treatment against SCD. However, the aldehyde functional group metabolic instability has severly hampered their development, except for voxelotor, which was approved in 2019 for SCD treatment. To improve the metabolic stability of aromatic aldehydes, we designed and synthesized novel molecules by incorporating Michael acceptor reactive centers into the previously clinically studied aromatic aldehyde, 5-hydroxymethylfurfural (5-HMF). Eight such derivatives, referred to as MMA compounds were synthesized and studied for their functional and biological activities. Unlike 5-HMF, which forms Schiff-base interaction with αVal1 nitrogen of hemoglobin, the MMA compounds covalently interacted with βCys93, as evidenced by reverse-phase HPLC and disulfide exchange reaction, explaining their RBC sickling inhibitory activities, which at 2 mM and 5 mM, range from 0% to 21% and 9% to 64%, respectively. Additionally, the MMA compounds showed a second mechanism of sickling inhibition (12%-41% and 13%-62% at 2 mM and 5 mM, respectively) by directly destabilizing the sickle hemoglobin polymer. In vitro studies demonstrated sustained pharmacologic activities of the compounds compared to 5-HMF. These findings hold promise for advancing SCD therapeutics.
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Affiliation(s)
- Abdelsattar M Omar
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia
- Center for Artificial Intelligence in Precision Medicines, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Osheiza Abdulmalik
- Division of Hematology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Khalid M El-Say
- Department of Pharmaceutics, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Mohini S Ghatge
- Department of Medicinal Chemistry, School of Pharmacy and Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Mojisola Cyril-Olutayo
- Division of Hematology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Steven Paredes
- Department of Medicinal Chemistry, School of Pharmacy and Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Mohammed Al-Awadh
- Department of Medicinal Chemistry, School of Pharmacy and Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Moustafa E El-Araby
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia
- Center for Artificial Intelligence in Precision Medicines, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Martin K Safo
- Department of Medicinal Chemistry, School of Pharmacy and Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, Virginia, USA
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Gour A, Kour D, Pandian R, Bhardwaj M, Sawant SD, Kumar A, Nandi U. Ellagic Acid Exerts Dual Action to Curb the Pathophysiological Manifestations of Sickle Cell Disease and Attenuate the Hydroxyurea-Induced Myelosuppression in Berkeley Mice. ACS Pharmacol Transl Sci 2023; 6:868-877. [PMID: 37325443 PMCID: PMC10262317 DOI: 10.1021/acsptsci.3c00026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Indexed: 06/17/2023]
Abstract
The use of adjuvant therapy is an attractive approach to manage sickle cell disease (SCD) symptomatically. The present study aimed to investigate the potential of ellagic acid as an adjuvant therapy with hydroxyurea (HU), a key drug for SCD with myelosuppressive toxic effects. A panel of experiments was performed using SCD patient's blood (ex vivo) and transgenic mice model of SCD (in vivo). Ellagic acid exhibited the following beneficial pharmacological actions: (a) potent anti-sickling, polymerization inhibitory, and inherent non-hemolytic activity; (b) pronounced action to abrogate HU-induced neutropenia and to improve key hematological parameters during SCD (RBC, Hb, platelet levels); (c) considerable action to foster vascular tone (L-proline); (d) marked attenuating effect against oxidative stress (nitrotyrosine, hypoxanthine, MDA, GSH); (e) substantial inhibitory role against inflammation (analgesic activity and regulation of hemin, TNF-α, IL-1β, NF-κB/IκBα); (f) remarkable outcome of declining vaso-occlusive crisis (P-selectin, ERK1/2); (g) notable shielding deed against elevated biochemical marker for organ toxicity (creatinine); (h) noticeably prevented histopathological alterations of the spleen. Additionally, the pharmacokinetic study results of HU in the presence and absence of ellagic acid using a mouse model demonstrate that ellagic acid could be safely co-administered with HU. Overall findings suggest that ellagic acid is a promising candidate for adjuvant therapy in SCD based on its own significant ability against SCD and potentiating capability of HU action via targeting improvement at the various stages of pathophysiological complications during SCD and minimizing HU-induced toxicological manifestations.
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Affiliation(s)
- Abhishek Gour
- Pharmacology
Division, CSIR-Indian Institute of Integrative
Medicine, Jammu 180001, India
- Academy
of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Dilpreet Kour
- Pharmacology
Division, CSIR-Indian Institute of Integrative
Medicine, Jammu 180001, India
- Academy
of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Ramajayan Pandian
- Pharmacology
Division, CSIR-Indian Institute of Integrative
Medicine, Jammu 180001, India
- Academy
of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Mahir Bhardwaj
- Pharmacology
Division, CSIR-Indian Institute of Integrative
Medicine, Jammu 180001, India
- Academy
of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Sanghapal D. Sawant
- Academy
of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
- Natural
Products and Medicinal Chemistry Division, CSIR-Indian Institute of Integrative Medicine, Jammu 180001, India
| | - Ajay Kumar
- Pharmacology
Division, CSIR-Indian Institute of Integrative
Medicine, Jammu 180001, India
- Academy
of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Utpal Nandi
- Pharmacology
Division, CSIR-Indian Institute of Integrative
Medicine, Jammu 180001, India
- Academy
of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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Donkor AK, Pagare PP, Mughram MHAL, Safo MK. X-ray crystallography and sickle cell disease drug discovery-a tribute to Donald Abraham. Front Mol Biosci 2023; 10:1136970. [PMID: 37293554 PMCID: PMC10244664 DOI: 10.3389/fmolb.2023.1136970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 05/15/2023] [Indexed: 06/10/2023] Open
Abstract
X-ray crystallography and structure-based drug discovery have played a major role in the discovery of antisickling agents that target hemoglobin (Hb) for the treatment of sickle cell disease (SCD). Sickle cell disease, the most common inherited hematologic disorder, occurs as a result of a single point mutation of βGlu6 in normal human adult hemoglobin (HbA) to βVal6 in sickle hemoglobin (HbS). The disease is characterized by polymerization of HbS and sickling of red blood cells (RBCs), leading to several secondary pathophysiologies, including but not limited to vaso-occlusion, hemolytic anemia, oxidative stress, inflammation, stroke, pain crisis, and organ damage. Despite the fact that SCD was the first disease to have its molecular basis established, the development of therapies was for a very long time a challenge and took several decades to find therapeutic agents. The determination of the crystal structure of Hb by Max Perutz in the early 60s, and the pioneering X-ray crystallography research by Donald J. Abraham in the early 80s, which resulted in the first structures of Hb in complex with small molecule allosteric effectors of Hb, gave much hope that structure-based drug discovery (SBDD) could be used to accelerate development of antisickling drugs that target the primary pathophysiology of hypoxia-induced HbS polymerization to treat SCD. This article, which is dedicated to Donald J. Abraham, briefly reviews structural biology, X-ray crystallography and structure-based drug discovery from the perspective of Hb. The review also presents the impact of X-ray crystallography in SCD drug development using Hb as a target, emphasizing the major and important contributions by Don Abraham in this field.
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Design, Synthesis, and Investigation of Novel Nitric Oxide (NO)-Releasing Aromatic Aldehyde as Drug Candidates for the Treatment of Sickle Cell Disease. Molecules 2022; 27:molecules27206835. [PMID: 36296435 PMCID: PMC9610770 DOI: 10.3390/molecules27206835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 10/06/2022] [Accepted: 10/08/2022] [Indexed: 11/29/2022] Open
Abstract
Sickle cell disease (SCD) is caused by a single-point mutation, and the ensuing deoxygenation-induced polymerization of sickle hemoglobin (HbS), and reduction in bioavailability of vascular nitric oxide (NO), contribute to the pathogenesis of the disease. In a proof-of-concept study, we successfully incorporated nitrate ester groups onto two previously studied potent antisickling aromatic aldehydes, TD7 and VZHE039, to form TD7-NO and VZHE039-NO hybrids, respectively. These compounds are stable in buffer but demonstrated the expected release of NO in whole blood in vitro and in mice. The more promising VZHE039-NO retained the functional and antisickling activities of the parent VZHE039 molecule. Moreover, VZHE039-NO, unlike VZHE039, significantly attenuated RBC adhesion to laminin, suggesting this compound has potential in vivo RBC anti-adhesion properties relevant to vaso-occlusive events. Crystallographic studies show that, as with VZHE039, VZHE039-NO also binds to liganded Hb to make similar protein interactions. The knowledge gained during these investigations provides a unique opportunity to generate a superior candidate drug in SCD with enhanced benefits.
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Alramadhani D, Aljahdali AS, Abdulmalik O, Pierce BD, Safo MK. Metabolic Reprogramming in Sickle Cell Diseases: Pathophysiology and Drug Discovery Opportunities. Int J Mol Sci 2022; 23:7448. [PMID: 35806451 PMCID: PMC9266828 DOI: 10.3390/ijms23137448] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 06/27/2022] [Accepted: 06/30/2022] [Indexed: 01/19/2023] Open
Abstract
Sickle cell disease (SCD) is a genetic disorder that affects millions of individuals worldwide. Chronic anemia, hemolysis, and vasculopathy are associated with SCD, and their role has been well characterized. These symptoms stem from hemoglobin (Hb) polymerization, which is the primary event in the molecular pathogenesis of SCD and contributes to erythrocyte or red blood cell (RBC) sickling, stiffness, and vaso-occlusion. The disease is caused by a mutation at the sixth position of the β-globin gene, coding for sickle Hb (HbS) instead of normal adult Hb (HbA), which under hypoxic conditions polymerizes into rigid fibers to distort the shapes of the RBCs. Only a few therapies are available, with the universal effectiveness of recently approved therapies still being monitored. In this review, we first focus on how sickle RBCs have altered metabolism and then highlight how this understanding reveals potential targets involved in the pathogenesis of the disease, which can be leveraged to create novel therapeutics for SCD.
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Affiliation(s)
- Dina Alramadhani
- Department of Medicinal Chemistry and the Institute for Structural Biology, Drug Discovery and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23298, USA;
| | - Anfal S. Aljahdali
- Department of Pharmaceutical Chemistry, King Abdulaziz University, Alsulaymanyah, Jeddah 21589, Saudi Arabia;
| | - Osheiza Abdulmalik
- Division of Hematology, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA;
| | - B. Daniel Pierce
- Department of Biology, University of Richmond, Richmond, VA 23173, USA;
| | - Martin K. Safo
- Department of Medicinal Chemistry and the Institute for Structural Biology, Drug Discovery and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23298, USA;
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Design, Synthesis, and Antisickling Investigation of a Nitric Oxide-Releasing Prodrug of 5HMF for the Treatment of Sickle Cell Disease. Biomolecules 2022; 12:biom12050696. [PMID: 35625623 PMCID: PMC9138457 DOI: 10.3390/biom12050696] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 05/05/2022] [Accepted: 05/10/2022] [Indexed: 02/02/2023] Open
Abstract
5-hydroxyfurfural (5HMF), an allosteric effector of hemoglobin (Hb) with an ability to increase Hb affinity for oxygen has been studied extensively for its antisickling effect in vitro and in vivo, and in humans for the treatment of sickle cell disease (SCD). One of the downstream pathophysiologies of SCD is nitric oxide (NO) deficiency, therefore increasing NO (bio)availability is known to mitigate the severity of SCD symptoms. We report the synthesis of an NO-releasing prodrug of 5HMF (5HMF-NO), which in vivo, is expected to be bio-transformed into 5HMF and NO, with concomitant therapeutic activities. In vitro studies showed that when incubated with whole blood, 5HMF-NO releases NO, as anticipated. When incubated with sickle blood, 5HMF-NO formed Schiff base adduct with Hb, increased Hb affinity for oxygen, and prevented hypoxia-induced erythrocyte sickling, which at 1 mM concentration were 16%, 10% and 27%, respectively, compared to 21%, 18% and 21% for 5HMF. Crystal structures of 5HMF-NO with Hb showed 5HMF-NO bound to unliganded (deoxygenated) Hb, while the hydrolyzed product, 5HMF bound to liganded (carbonmonoxy-ligated) Hb. Our findings from this proof-of-concept study suggest that the incorporation of NO donor group to 5HMF and analogous molecules could be a novel beneficial strategy to treat SCD and warrants further detailed in vivo studies.
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Buks R, Dagher T, Rotordam MG, Monedero Alonso D, Cochet S, Gautier EF, Chafey P, Cassinat B, Kiladjian JJ, Becker N, Plo I, Egée S, El Nemer W. Altered Ca 2+ Homeostasis in Red Blood Cells of Polycythemia Vera Patients Following Disturbed Organelle Sorting during Terminal Erythropoiesis. Cells 2021; 11:49. [PMID: 35011611 PMCID: PMC8750512 DOI: 10.3390/cells11010049] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 12/20/2021] [Accepted: 12/21/2021] [Indexed: 02/07/2023] Open
Abstract
Over 95% of Polycythemia Vera (PV) patients carry the V617F mutation in the tyrosine kinase Janus kinase 2 (JAK2), resulting in uncontrolled erythroid proliferation and a high risk of thrombosis. Using mass spectrometry, we analyzed the RBC membrane proteome and showed elevated levels of multiple Ca2+ binding proteins as well as endoplasmic-reticulum-residing proteins in PV RBC membranes compared with RBC membranes from healthy individuals. In this study, we investigated the impact of JAK2V617F on (1) calcium homeostasis and RBC ion channel activity and (2) protein expression and sorting during terminal erythroid differentiation. Our data from automated patch-clamp show modified calcium homeostasis in PV RBCs and cell lines expressing JAK2V617F, with a functional impact on the activity of the Gárdos channel that could contribute to cellular dehydration. We show that JAK2V617F could play a role in organelle retention during the enucleation step of erythroid differentiation, resulting in modified whole cell proteome in reticulocytes and RBCs in PV patients. Given the central role that calcium plays in the regulation of signaling pathways, our study opens new perspectives to exploring the relationship between JAK2V617F, calcium homeostasis, and cellular abnormalities in myeloproliferative neoplasms, including cellular interactions in the bloodstream in relation to thrombotic events.
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Affiliation(s)
- Ralfs Buks
- BIGR, UMR_S1134, Inserm, Université de Paris, F-75015 Paris, France; (R.B.); (S.C.)
- Institut National de la Transfusion Sanguine, F-75015 Paris, France
- Laboratoire d’Excellence GR-Ex, F-75015 Paris, France; (T.D.); (D.M.A.); (E.-F.G.); (B.C.); (J.-J.K.); (I.P.); (S.E.)
| | - Tracy Dagher
- Laboratoire d’Excellence GR-Ex, F-75015 Paris, France; (T.D.); (D.M.A.); (E.-F.G.); (B.C.); (J.-J.K.); (I.P.); (S.E.)
- U1287, Inserm, Université Paris-Saclay, Gustave Roussy, F-94800 Villejuif, France
| | - Maria Giustina Rotordam
- Nanion Technologies GmbH, 80339 Munich, Germany; (M.G.R.); (N.B.)
- Theoretical Medicine and Biosciences, Medical Faculty, Saarland University, Kirrbergerstr. 100, DE-66424 Homburg, Germany
| | - David Monedero Alonso
- Laboratoire d’Excellence GR-Ex, F-75015 Paris, France; (T.D.); (D.M.A.); (E.-F.G.); (B.C.); (J.-J.K.); (I.P.); (S.E.)
- Sorbonne Université, CNRS, UMR LBI2M, Station Biologique de Roscoff SBR, F-29680 Roscoff, France
| | - Sylvie Cochet
- BIGR, UMR_S1134, Inserm, Université de Paris, F-75015 Paris, France; (R.B.); (S.C.)
- Institut National de la Transfusion Sanguine, F-75015 Paris, France
- Laboratoire d’Excellence GR-Ex, F-75015 Paris, France; (T.D.); (D.M.A.); (E.-F.G.); (B.C.); (J.-J.K.); (I.P.); (S.E.)
| | - Emilie-Fleur Gautier
- Laboratoire d’Excellence GR-Ex, F-75015 Paris, France; (T.D.); (D.M.A.); (E.-F.G.); (B.C.); (J.-J.K.); (I.P.); (S.E.)
- Institut Imagine-INSERM U1163, Necker Hospital, Université de Paris, F-75015 Paris, France
- Proteomics Platform 3P5, Université de Paris, Institut Cochin, INSERM, U1016, CNRS, UMR8104 Paris, France;
| | - Philippe Chafey
- Proteomics Platform 3P5, Université de Paris, Institut Cochin, INSERM, U1016, CNRS, UMR8104 Paris, France;
| | - Bruno Cassinat
- Laboratoire d’Excellence GR-Ex, F-75015 Paris, France; (T.D.); (D.M.A.); (E.-F.G.); (B.C.); (J.-J.K.); (I.P.); (S.E.)
- IRSL, U1131, INSERM, Université de Paris, F-75010 Paris, France
- Hôpital Saint-Louis, Laboratoire de Biologie Cellulaire, AP-HP, F-75010 Paris, France
| | - Jean-Jacques Kiladjian
- Laboratoire d’Excellence GR-Ex, F-75015 Paris, France; (T.D.); (D.M.A.); (E.-F.G.); (B.C.); (J.-J.K.); (I.P.); (S.E.)
- IRSL, U1131, INSERM, Université de Paris, F-75010 Paris, France
- Centre d’Investigations Cliniques, Hôpital Saint-Louis, Université de Paris, F-75010 Paris, France
| | - Nadine Becker
- Nanion Technologies GmbH, 80339 Munich, Germany; (M.G.R.); (N.B.)
| | - Isabelle Plo
- Laboratoire d’Excellence GR-Ex, F-75015 Paris, France; (T.D.); (D.M.A.); (E.-F.G.); (B.C.); (J.-J.K.); (I.P.); (S.E.)
- U1287, Inserm, Université Paris-Saclay, Gustave Roussy, F-94800 Villejuif, France
| | - Stéphane Egée
- Laboratoire d’Excellence GR-Ex, F-75015 Paris, France; (T.D.); (D.M.A.); (E.-F.G.); (B.C.); (J.-J.K.); (I.P.); (S.E.)
- Sorbonne Université, CNRS, UMR LBI2M, Station Biologique de Roscoff SBR, F-29680 Roscoff, France
| | - Wassim El Nemer
- BIGR, UMR_S1134, Inserm, Université de Paris, F-75015 Paris, France; (R.B.); (S.C.)
- Institut National de la Transfusion Sanguine, F-75015 Paris, France
- Laboratoire d’Excellence GR-Ex, F-75015 Paris, France; (T.D.); (D.M.A.); (E.-F.G.); (B.C.); (J.-J.K.); (I.P.); (S.E.)
- Etablissement Français du Sang PACA-Corse, F-13005Marseille, France
- Aix Marseille Univ, EFS, CNRS, ADES, “Biologie des Groupes Sanguins”, F-13005 Marseille, France
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Ahmed TA, El-Say KM, Abd-Allah FI, Omar AM, El-Araby ME, Muhammad YA, Pagare PP, Zhang Y, Mohmmad KA, Abdulmalik O, Safo MK. Improving the Solubility and Oral Bioavailability of a Novel Aromatic Aldehyde Antisickling Agent (PP10) for the Treatment of Sickle Cell Disease. Pharmaceutics 2021; 13:1148. [PMID: 34452107 PMCID: PMC8401948 DOI: 10.3390/pharmaceutics13081148] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 07/15/2021] [Accepted: 07/23/2021] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Aromatic aldehydes, with their ability to increase the oxygen affinity of sickle hemoglobin, have become important therapeutic agents for sickle cell disease (SCD). One such compound, voxelotor, was recently approved for SCD treatment. Methyl 6-((2-formyl-3-hydroxyphenoxy)methyl) picolinate (PP10) is another promising aromatic aldehyde, recently reported by our group. Like voxelotor, PP10 exhibits O2-dependent antisickling activity, but, unlike voxelotor, PP10 shows unique O2-independent antisickling effect. PP10, however, has limited solubility. This study therefore aimed to develop oral and parenteral formulations to improve PP10 solubility and bioavailability. METHODS Oral drug tablets with 2-hydroxypropyl beta cyclodextrin (HP-β-CD), polyvinylpyrrolidone, or Eudragit L100-55 PP10-binary system, and an intravenous (IV) formulation with d-α-tocopherol polyethylene glycol 1000 succinate (TPGS) or HP-β-CD, were developed. The pharmacokinetic behavior of the formulations was studied in Sprague-Dawley rats. PP10, a methylester, and its acid metabolite were also studied in vitro with sickle whole blood to determine their effect on Hb modification, Hb oxygen affinity, and sickle red blood cell inhibition. RESULTS Aqueous solubility of PP10 was enhanced ~5 times with the HP-β-CD binary system, while the TPGS aqueous micelle formulation was superior, with a drug concentration of 0.502 ± 0.01 mg/mL and a particle size of 26 ± 3 nm. The oral tablets showed relative and absolute bioavailabilities of 173.4% and 106.34%, respectively. The acid form of PP10 appeared to dominate in vivo, although both PP10 forms demonstrated pharmacologic effect. CONCLUSION Oral and IV formulations of PP10 were successfully developed using HP-β-CD binary system and TPGS aqueous micelles, respectively, resulting in significantly improved solubility and bioavailability.
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Affiliation(s)
- Tarek A. Ahmed
- Department of Pharmaceutics, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia;
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Al-Azhar University, Cairo 11884, Egypt;
| | - Khalid M. El-Say
- Department of Pharmaceutics, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia;
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Al-Azhar University, Cairo 11884, Egypt;
| | - Fathy I. Abd-Allah
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Al-Azhar University, Cairo 11884, Egypt;
| | - Abdelsattar M. Omar
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (A.M.O.); (M.E.E.-A.); (Y.A.M.); (K.A.M.)
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Al-Azhar University, Cairo 11884, Egypt
| | - Moustafa E. El-Araby
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (A.M.O.); (M.E.E.-A.); (Y.A.M.); (K.A.M.)
| | - Yosra A. Muhammad
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (A.M.O.); (M.E.E.-A.); (Y.A.M.); (K.A.M.)
| | - Piyusha P. Pagare
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA 23298, USA; (P.P.P.); (Y.Z.); (M.K.S.)
| | - Yan Zhang
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA 23298, USA; (P.P.P.); (Y.Z.); (M.K.S.)
| | - Khadijah A. Mohmmad
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (A.M.O.); (M.E.E.-A.); (Y.A.M.); (K.A.M.)
| | - Osheiza Abdulmalik
- Division of Hematology, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA;
| | - Martin K. Safo
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA 23298, USA; (P.P.P.); (Y.Z.); (M.K.S.)
- Development, School of Pharmacy, The Institute for Structural Biology, Drug Discovery, Virginia Commonwealth University, Richmond, VA 23298, USA
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10
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Omar AM, Abdulmalik O, Ghatge MS, Muhammad YA, Paredes SD, El-Araby ME, Safo MK. An Investigation of Structure-Activity Relationships of Azolylacryloyl Derivatives Yielded Potent and Long-Acting Hemoglobin Modulators for Reversing Erythrocyte Sickling. Biomolecules 2020; 10:E1508. [PMID: 33147875 PMCID: PMC7693414 DOI: 10.3390/biom10111508] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/25/2020] [Accepted: 10/30/2020] [Indexed: 12/27/2022] Open
Abstract
Aromatic aldehydes that bind to sickle hemoglobin (HbS) to increase the protein oxygen affinity and/or directly inhibit HbS polymer formation to prevent the pathological hypoxia-induced HbS polymerization and the subsequent erythrocyte sickling have for several years been studied for the treatment of sickle cell disease (SCD). With the exception of Voxelotor, which was recently approved by the U.S. Food and Drug Administration (FDA) to treat the disease, several other promising antisickling aromatic aldehydes have not fared well in the clinic because of metabolic instability of the aldehyde moiety, which is critical for the pharmacologic activity of these compounds. Over the years, our group has rationally developed analogs of aromatic aldehydes that incorporate a stable Michael addition reactive center that we hypothesized would form covalent interactions with Hb to increase the protein affinity for oxygen and prevent erythrocyte sickling. Although, these compounds have proven to be metabolically stable, unfortunately they showed weak to no antisickling activity. In this study, through additional targeted modifications of our lead Michael addition compounds, we have discovered other novel antisickling agents. These compounds, designated MMA, bind to the α-globin and/or β-globin to increase Hb affinity for oxygen and concomitantly inhibit erythrocyte sickling with significantly enhanced and sustained pharmacologic activities in vitro.
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Affiliation(s)
- Abdelsattar M. Omar
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Alsulaymanyah, Jeddah 21589, Saudi Arabia; (Y.A.M.); (M.E.E.-A.)
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Al-Azhar University, Cairo 11884, Egypt
| | - Osheiza Abdulmalik
- Division of Hematology, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA;
| | - Mohini S. Ghatge
- Department of Medicinal Chemistry, School of Pharmacy and Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, VA 23219, USA; (M.S.G.); (S.D.P.)
| | - Yosra A. Muhammad
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Alsulaymanyah, Jeddah 21589, Saudi Arabia; (Y.A.M.); (M.E.E.-A.)
| | - Steven D. Paredes
- Department of Medicinal Chemistry, School of Pharmacy and Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, VA 23219, USA; (M.S.G.); (S.D.P.)
| | - Moustafa E. El-Araby
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Alsulaymanyah, Jeddah 21589, Saudi Arabia; (Y.A.M.); (M.E.E.-A.)
| | - Martin K. Safo
- Department of Medicinal Chemistry, School of Pharmacy and Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, VA 23219, USA; (M.S.G.); (S.D.P.)
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11
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Abstract
This chapter reviews how allosteric (heterotrophic) effectors and natural mutations impact hemoglobin (Hb) primary physiological function of oxygen binding and transport. First, an introduction about the structure of Hb is provided, including the ensemble of tense and relaxed Hb states and the dynamic equilibrium of Hb multistate. This is followed by a brief review of Hb variants with altered Hb structure and oxygen binding properties. Finally, a review of different endogenous and exogenous allosteric effectors of Hb is presented with particular emphasis on the atomic interactions of synthetic ligands with altered allosteric function of Hb that could potentially be harnessed for the treatment of diseases.
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Affiliation(s)
- Mostafa H Ahmed
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, VA, 23219, USA
| | - Mohini S Ghatge
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, VA, 23219, USA.,Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, VA, 23219, USA
| | - Martin K Safo
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, VA, 23219, USA. .,Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, VA, 23219, USA.
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12
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Antwi-Boasiako C, Kusi-Mensah YA, Hayfron-Benjamin C, Aryee R, Dankwah GB, Abla KL, Owusu Darkwa E, Botchway FA, Sampene-Donkor E. Serum Potassium, Sodium, and Chloride Levels in Sickle Cell Disease Patients and Healthy Controls: A Case-Control Study at Korle-Bu Teaching Hospital, Accra. Biomark Insights 2019; 14:1177271919873889. [PMID: 31523130 PMCID: PMC6728659 DOI: 10.1177/1177271919873889] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 08/13/2019] [Indexed: 11/21/2022] Open
Abstract
The activity of Na+-K+ ATPase is altered in sickle cell
disease (SCD), which affects serum electrolyte levels. This alteration is
associated with several complications in sickle cell patients. This study
evaluated the serum levels of sodium, potassium, and chloride in patients with
SCD. The study was a case-control cross-sectional study involving 120 SCD
patients in the steady state and 48 ‘healthy’ controls. The SCD patients were
made up of 69 HbSS patients and 41 HbSC patients. Serum electrolyte levels
(Na+, K+, and Cl−) were measured using a
Flame Atomic Absorption Spectrometer (Variant 240FS; Varian Australia Pty Ltd).
Serum sodium levels were significantly lower in the sickle cell patients,
compared with their ‘healthy’ counterparts (P = .0001).
Although the study found significantly higher serum levels of potassium in the
SCD patients (P = .0001), there was no significant difference
in serum chloride levels between patients with SCD and the controls
(P = .098). Serum sodium and chloride levels were not
significantly different in both HbSS and HbSC patients
(P = .197 and P = .553, respectively). The
level of serum potassium in the HbSS patients was, however, significantly higher
compared with those with the HbSC genotype (P = .0001). There
is higher efflux of K+ from the intracellular into the extracellular
space in HbSS patients, which may lead to red cell membrane dysfunction and
associated complications.
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Affiliation(s)
- Charles Antwi-Boasiako
- Department of Physiology, School of
Biomedical and Allied Health Sciences, University of Ghana, Accra, Ghana
- Charles Antwi-Boasiako, Department of
Physiology, School of Biomedical and Allied Health Sciences, College of Health
Sciences, University of Ghana, P.O. Box 143, Korle-Bu, Accra 00233, Ghana.
| | - Yaw A Kusi-Mensah
- Department of Physiology, School of
Biomedical and Allied Health Sciences, University of Ghana, Accra, Ghana
- Department of Anaesthesia, School of
Medicine and Dentistry, University of Ghana, Accra, Ghana
| | - Charles Hayfron-Benjamin
- Department of Physiology, School of
Biomedical and Allied Health Sciences, University of Ghana, Accra, Ghana
- Department of Anaesthesia, School of
Medicine and Dentistry, University of Ghana, Accra, Ghana
| | - Robert Aryee
- Department of Physiology, School of
Biomedical and Allied Health Sciences, University of Ghana, Accra, Ghana
| | - Gifty Boatemaah Dankwah
- Department of Physiology, School of
Biomedical and Allied Health Sciences, University of Ghana, Accra, Ghana
| | - Kwawukume Lim Abla
- Department of Physiology, School of
Biomedical and Allied Health Sciences, University of Ghana, Accra, Ghana
- Department of Internal Medicine,
Korle-Bu Teaching Hospital, Accra, Ghana
| | - Ebenezer Owusu Darkwa
- Department of Anaesthesia, School of
Medicine and Dentistry, University of Ghana, Accra, Ghana
| | - Felix Abekah Botchway
- Department of Chemical Pathology, School
of Biomedical and Allied Health Sciences, University of Ghana, Accra, Ghana
| | - Eric Sampene-Donkor
- Department of Medical Microbiology,
School of Biomedical and Allied Health Sciences, University of Ghana, Accra,
Ghana
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13
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New Therapeutic Options for the Treatment of Sickle Cell Disease. Mediterr J Hematol Infect Dis 2019; 11:e2019002. [PMID: 30671208 PMCID: PMC6328043 DOI: 10.4084/mjhid.2019.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 11/11/2018] [Indexed: 02/08/2023] Open
Abstract
Sickle cell disease (SCD; ORPHA232; OMIM # 603903) is a chronic and invalidating disorder distributed worldwide, with high morbidity and mortality. Given the disease complexity and the multiplicity of pathophysiological targets, development of new therapeutic options is critical, despite the positive effects of hydroxyurea (HU), for many years the only approved drug for SCD. New therapeutic strategies might be divided into (1) pathophysiology-related novel therapies and (2) innovations in curative therapeutic options such as hematopoietic stem cell transplantation and gene therapy. The pathophysiology related novel therapies are: a) Agents which reduce sickling or prevent sickle red cell dehydration; b) Agents targeting SCD vasculopathy and sickle cell-endothelial adhesive events; c) Anti-oxidant agents. This review highlights new therapeutic strategies in SCD and discusses future developments, research implications, and possible innovative clinical trials.
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14
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Yousif OO, Hassan MK, Al-Naama LM. Red Blood Cell and Serum Magnesium Levels Among Children and Adolescents With Sickle Cell Anemia. Biol Trace Elem Res 2018; 186:295-304. [PMID: 29637408 DOI: 10.1007/s12011-018-1307-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 03/13/2018] [Indexed: 01/12/2023]
Abstract
Patients with sickle cell anemia (SCA) can acquire many biochemical abnormalities, including altered magnesium levels. However, the roles of magnesium in the pathogenesis and management of SCA need to be determined. The aim of this work was to evaluate magnesium levels among pediatric patients with SCA in Basra, Iraq. The study employed a case-control design and examined 87 patients with SCA (3-15 years old) who had attended the Basra Center for Hereditary Blood Diseases while in a steady state and 90 apparently healthy control subjects. Complete blood count, red blood cell (RBC), and serum magnesium, calcium, potassium, sodium, zinc, and copper levels were measured in all subjects. The results revealed significantly lower RBC and serum magnesium levels among the patients with SCA (3.62 ± 0.42 and 1.35 ± 0.19 mg/dL, respectively) than those among the control subjects (4.47 ± 0.55 and 1.87 ± 0.27 mg/dL, respectively). In addition, compared to the control subjects, the patients with SCA had significantly lower serum levels of potassium, sodium, and zinc; significantly higher serum levels of copper; and significantly higher Ca/Mg and Na/Mg ratios. Among the SCA patients, the RBC magnesium level was significantly negatively associated with the frequencies of vaso-occlusive crises (r = - 0.423, P < 0.001) and disease-related hospitalization (r = - 0.225, P < 0.05). To conclude, the RBC magnesium level, but not the serum magnesium level, is significantly associated with vaso-occlusive crises and hospitalization. Therefore, screening and management of low RBC magnesium levels in SCA patients are required.
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Affiliation(s)
- Osama Omar Yousif
- Basra Pediatric Specialty Hospital, Basra Health Directorate, Basra, Iraq
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15
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Góis CRTD, D'Ávila JS, Cipolotti R, Lira ADS, Silva ALL. Adenotonsillar Hypertrophy in Pre-School Children with Sickle Cell Disease and Diagnostic Accuracy of the Sleep Disturbance Scale for Children. Int Arch Otorhinolaryngol 2018; 22:55-59. [PMID: 29371899 PMCID: PMC5783688 DOI: 10.1055/s-0037-1602702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Accepted: 03/18/2017] [Indexed: 11/10/2022] Open
Abstract
Introduction
Adenotonsillar hypertrophy is more common in children with sickle cell disease, and can lead to sleep-disordered breathing.
Objectives
To determine the frequency of adenotonsillar hypertrophy in pre-school children with sickle cell disease and assess the diagnostic accuracy of the sleep-disordered breathing subscale in the Sleep Disturbance Scale for Children.
Method
Observational study with a group of 48 children with sickle cell disease and a control group of 35 children without the disease. The children underwent oropharingoscopy and video nasal endoscopy. The parents and/or guardians answered the questions of the subscale.
Results
Adenotonsillar hypertrophy was observed in 25% of the children in the study group, and in 20% of the children in the control group, with no statistical difference between the groups. The subscale score ranged from 3 to 11 in both groups. There was a statistical significance in the study group. The average was 4.79 (standard deviation [SD] ± 2.50), with 4.19 (SD ± 1.72) among the children without adenotonsillar hypertrophy, and 6.5 (SD ± 3.40) among the children with adenotonsillar hypertrophy. There was also a statistical significance in the control group. The average was 5.23 (SD ± 2.81), with 4.44 (SD ± 2.2) among the children without adenotonsillar hypertrophy, and 7.87 (SD ± 2.89) among the children with adenotonsillar hypertrophy.
Conclusion
Adenotonsillar hypertrophy was not associated with sickle cell disease in pre-school children. The subscale of sleep-disordered breathing in the Sleep Disturbance Scale for Children was a useful tool for the diagnostic suspicion of adenotonsillar hypertrophy in children in this age group.
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Affiliation(s)
| | | | - Rosana Cipolotti
- Department of Medicine, Universidade Federal de Sergipe (UFS), Aracaju, SE, Brazil
| | - Amanda da Silva Lira
- Department of Statistics and Actuarial Sciences, Universidade Federal de Sergipe (UFS), São Cristóvão, SE, Brazil
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16
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Moras M, Lefevre SD, Ostuni MA. From Erythroblasts to Mature Red Blood Cells: Organelle Clearance in Mammals. Front Physiol 2017; 8:1076. [PMID: 29311991 PMCID: PMC5742207 DOI: 10.3389/fphys.2017.01076] [Citation(s) in RCA: 184] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 12/06/2017] [Indexed: 12/14/2022] Open
Abstract
Erythropoiesis occurs mostly in bone marrow and ends in blood stream. Mature red blood cells are generated from multipotent hematopoietic stem cells, through a complex maturation process involving several morphological changes to produce a highly functional specialized cells. In mammals, terminal steps involved expulsion of the nucleus from erythroblasts that leads to the formation of reticulocytes. In order to produce mature biconcave red blood cells, organelles and ribosomes are selectively eliminated from reticulocytes as well as the plasma membrane undergoes remodeling. The mechanisms involved in these last maturation steps are still under investigation. Enucleation involves dramatic chromatin condensation and establishment of the nuclear polarity, which is driven by a rearrangement of actin cytoskeleton and the clathrin-dependent generation of vacuoles at the nuclear-cytoplasmic junction. This process is favored by interaction between the erythroblasts and macrophages at the erythroblastic island. Mitochondria are eliminated by mitophagy. This is a macroautophagy pathway consisting in the engulfment of mitochondria into a double-membrane structure called autophagosome before degradation. Several mice knock-out models were developed to identify mitophagy-involved proteins during erythropoiesis, but whole mechanisms are not completely determined. Less is known concerning the clearance of other organelles, such as smooth and rough ER, Golgi apparatus and ribosomes. Understanding the modulators of organelles clearance in erythropoiesis may elucidate the pathogenesis of different dyserythropoietic diseases such as myelodysplastic syndrome, leukemia and anemia.
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Affiliation(s)
| | | | - Mariano A. Ostuni
- UMR-S1134 Integrated Biology of Red Blood Cell, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, Paris, France
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17
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Xu GG, Pagare PP, Ghatge MS, Safo RP, Gazi A, Chen Q, David T, Alabbas AB, Musayev FN, Venitz J, Zhang Y, Safo MK, Abdulmalik O. Design, Synthesis, and Biological Evaluation of Ester and Ether Derivatives of Antisickling Agent 5-HMF for the Treatment of Sickle Cell Disease. Mol Pharm 2017; 14:3499-3511. [PMID: 28858508 PMCID: PMC5871537 DOI: 10.1021/acs.molpharmaceut.7b00553] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Candidate drugs to counter intracellular polymerization of deoxygenated sickle hemoglobin (Hb S) continue to represent a promising approach to mitigating the primary cause of the pathophysiology associated with sickle cell disease (SCD). One such compound is the naturally occurring antisickling agent, 5-hydroxymethyl-2-furfural (5-HMF), which has been studied in the clinic for the treatment of SCD. As part of our efforts to develop novel efficacious drugs with improved pharmacologic properties, we structurally modified 5-HMF into 12 ether and ester derivatives. The choice of 5-HMF as a pharmacophore was influenced by a combination of its demonstrated attractive hemoglobin modifying and antisickling properties, well-known safety profiles, and its reported nontoxic major metabolites. The derivatives were investigated for their time- and/or dose-dependent effects on important antisickling parameters, such as modification of hemoglobin, corresponding changes in oxygen affinity, and inhibition of red blood cell sickling. The novel test compounds bound and modified Hb and concomitantly increased the protein affinity for oxygen. Five of the derivatives exhibited 1.5- to 4.0-fold higher antisickling effects than 5-HMF. The binding mode of the compounds with Hb was confirmed by X-ray crystallography and, in part, helps explain their observed biochemical properties. Our findings, in addition to the potential therapeutic application, provide valuable insights and potential guidance for further modifications of these (and similar) compounds to enhance their pharmacologic properties.
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Affiliation(s)
- Guoyan G. Xu
- Department of Medicinal Chemistry, and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Piyusha P. Pagare
- Department of Medicinal Chemistry, and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Mohini S. Ghatge
- Department of Medicinal Chemistry, and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
- The Institute for Structural Biology, Drug Discovery, and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Ronni P. Safo
- The Institute for Structural Biology, Drug Discovery, and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Aheema Gazi
- Department of Biology, School of Arts & Sciences, University of Richmond, Richmond, Virginia 23173, United States
| | - Qiukan Chen
- Division of Hematology, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, United States
| | - Tanya David
- The Institute for Structural Biology, Drug Discovery, and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Alhumaidi B. Alabbas
- Department of Medicinal Chemistry, and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
- The Institute for Structural Biology, Drug Discovery, and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Faik N. Musayev
- Department of Medicinal Chemistry, and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
- The Institute for Structural Biology, Drug Discovery, and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Jürgen Venitz
- Department of Pharmaceutics, and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Yan Zhang
- Department of Medicinal Chemistry, and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Martin K. Safo
- Department of Medicinal Chemistry, and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
- The Institute for Structural Biology, Drug Discovery, and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Osheiza Abdulmalik
- Division of Hematology, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, United States
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18
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Adewoyin AS, Oghuvwu OS, Awodu OA. Hydroxyurea therapy in adult Nigerian sickle cell disease: a monocentric survey on pattern of use, clinical effects and patient's compliance. Afr Health Sci 2017; 17:255-261. [PMID: 29026400 DOI: 10.4314/ahs.v17i1.31] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND The clinical prospects of hydroxyurea therapy in the management of sickle cell disease (SCD) require evaluation in the Nigerian setting to develop indigenous guidelines. This survey examines the pattern of hydroxyurea therapy, its clinico-haematologic benefits and safety profile in Nigerian SCD subjects. METHODS A cross sectional pilot survey was carried out among 60 adult SCD subjects over 3 months. Data on clinical phenotypes, relevant haematological parameters and details of hydroxyurea therapy were obtained using a structured questionnaire through an interview process and case file review. RESULTS The median age was 30 years. Thirty-four (56.7%) of the subjects are aware of hydroxyurea therapy in SCD. Twenty-four (40%) SCD patients had previously used hydroxyurea. Only 4 subjects were fully compliant. Reasons for non-compliance included poor knowledge and lack of funds. In particular, hydroxyurea reduced leucocyte count and increased mean red cell volume (MCV) in compliant subjects. CONCLUSION Hydroxyurea use is low among Nigerian SCD subjects despite its proven efficacy/clinical prospects in the developed nations. Large scale multicenter studies and clinical trials are needed to form a basis for developing standard local treatment protocol for its use.
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Affiliation(s)
- Ademola Samson Adewoyin
- Department of Haematology and Blood Transfusion, University of Benin Teaching Hospital, PMB 1111, Benin City, Nigeria
| | - Omokiniovo Sunday Oghuvwu
- Department of Internal Medicine, Clinical Pharmacology and Therapeutics Unit, University of Benin Teaching Hospital, PMB 1111, Benin City, Nigeria
| | - Omolade Augustina Awodu
- Department of Haematology and Blood Transfusion, University of Benin Teaching Hospital, PMB 1111, Benin City, Nigeria
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19
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Aryloxyalkanoic Acids as Non-Covalent Modifiers of the Allosteric Properties of Hemoglobin. Molecules 2016; 21:molecules21081057. [PMID: 27529207 PMCID: PMC5453642 DOI: 10.3390/molecules21081057] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 07/29/2016] [Accepted: 08/09/2016] [Indexed: 11/16/2022] Open
Abstract
Hemoglobin (Hb) modifiers that stereospecifically inhibit sickle hemoglobin polymer formation and/or allosterically increase Hb affinity for oxygen have been shown to prevent the primary pathophysiology of sickle cell disease (SCD), specifically, Hb polymerization and red blood cell sickling. Several such compounds are currently being clinically studied for the treatment of SCD. Based on the previously reported non-covalent Hb binding characteristics of substituted aryloxyalkanoic acids that exhibited antisickling properties, we designed, synthesized and evaluated 18 new compounds (KAUS II series) for enhanced antisickling activities. Surprisingly, select test compounds showed no antisickling effects or promoted erythrocyte sickling. Additionally, the compounds showed no significant effect on Hb oxygen affinity (or in some cases, even decreased the affinity for oxygen). The X-ray structure of deoxygenated Hb in complex with a prototype compound, KAUS-23, revealed that the effector bound in the central water cavity of the protein, providing atomic level explanations for the observed functional and biological activities. Although the structural modification did not lead to the anticipated biological effects, the findings provide important direction for designing candidate antisickling agents, as well as a framework for novel Hb allosteric effectors that conversely, decrease the protein affinity for oxygen for potential therapeutic use for hypoxic- and/or ischemic-related diseases.
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20
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Ghatge MS, Ahmed MH, Omar ASM, Pagare PP, Rosef S, Kellogg GE, Abdulmalik O, Safo MK. Crystal structure of carbonmonoxy sickle hemoglobin in R-state conformation. J Struct Biol 2016; 194:446-50. [PMID: 27085422 DOI: 10.1016/j.jsb.2016.04.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 04/08/2016] [Accepted: 04/09/2016] [Indexed: 02/08/2023]
Abstract
The fundamental pathophysiology of sickle cell disease is predicated by the polymerization of deoxygenated (T-state) sickle hemoglobin (Hb S) into fibers that distort red blood cells into the characteristic sickle shape. The crystal structure of deoxygenated Hb S (DeoxyHb S) and other studies suggest that the polymer is initiated by a primary interaction between the mutation βVal6 from one Hb S molecule, and a hydrophobic acceptor pocket formed by the residues βAla70, βPhe85 and βLeu88 of an adjacent located Hb S molecule. On the contrary, oxygenated or liganded Hb S does not polymerize or incorporate in the polymer. In this paper we present the crystal structure of carbonmonoxy-ligated sickle Hb (COHb S) in the quaternary classical R-state at 1.76Å. The overall structure and the pathological donor and acceptor environments of COHb S are similar to those of the isomorphous CO-ligated R-state normal Hb (COHb A), but differ significantly from DeoxyHb S as expected. More importantly, the packing of COHb S molecules does not show the typical pathological interaction between βVal6 and the βAla70, βPhe85 and βLeu88 hydrophobic acceptor pocket observed in DeoxyHb S crystal. The structural analysis of COHb S, COHb A and DeoxyHb S provides atomic level insight into why liganded hemoglobin does not form a polymer.
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Affiliation(s)
- Mohini S Ghatge
- Department of Medicinal Chemistry, and The Institute for Structural Biology, Drug Discovery and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23298, United States
| | - Mostafa H Ahmed
- Department of Medicinal Chemistry, and The Institute for Structural Biology, Drug Discovery and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23298, United States
| | - Abdel Sattar M Omar
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Alsulaymanyah, Jeddah 21589, Saudi Arabia; Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Al-Azhar University, Cairo 11884, Egypt
| | - Piyusha P Pagare
- Department of Medicinal Chemistry, and The Institute for Structural Biology, Drug Discovery and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23298, United States
| | - Susan Rosef
- Division of Clinical Pathology, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23298, United States
| | - Glen E Kellogg
- Department of Medicinal Chemistry, and The Institute for Structural Biology, Drug Discovery and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23298, United States
| | - Osheiza Abdulmalik
- Division of Hematology, The Children's Hospital of Philadelphia, PA 19104, United States
| | - Martin K Safo
- Department of Medicinal Chemistry, and The Institute for Structural Biology, Drug Discovery and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23298, United States.
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21
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van Zuuren EJ, Fedorowicz Z. Low-molecular-weight heparins for managing vaso-occlusive crises in people with sickle cell disease. Cochrane Database Syst Rev 2015; 2015:CD010155. [PMID: 26684281 PMCID: PMC7087472 DOI: 10.1002/14651858.cd010155.pub3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
BACKGROUND Sickle cell disease is one of the most common and severe genetic disorders in the world. It can be broadly divided into two distinct clinical phenotypes characterized by either haemolysis or vaso-occlusion. Pain is the most prominent symptom of vaso-occlusion, and hypercoagulability is a well-established pathogenic phenomenon in people with sickle cell disease. Low-molecular-weight heparins might control this hypercoagulable state through their anticoagulant effect. This is an update of a previously published version of this review. OBJECTIVES To assess the effects of low-molecular-weight heparins for managing vaso-occlusive crises in people with sickle cell disease. SEARCH METHODS We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register comprising references identified from comprehensive electronic database searches. We also searched abstract books of conference proceedings and several online trials registries for ongoing trials.Date of the last search of the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register: 28 September 2015. SELECTION CRITERIA Randomised controlled clinical trials and controlled clinical trials that assessed the effects of low-molecular-weight heparins in the management of vaso-occlusive crises in people with sickle cell disease. DATA COLLECTION AND ANALYSIS Study selection, data extraction, assessment of risk of bias and analyses were carried out independently by the two review authors. MAIN RESULTS Two studies comprising 287 participants were included. One study (with an overall unclear to high risk of bias) involved 253 participants and the quality of the evidence for most outcomes was very low. This study, reported that pain severity at day two and day three was lower in the tinzaparin group than in the placebo group (P < 0.01, analysis of variance (ANOVA)) and additionally at day 4 (P < 0.05 (ANOVA)). Thus tinzaparin resulted in more rapid resolution of pain, as measured with a numerical pain scale. The mean difference in duration of painful crises was statistically significant at -1.78 days in favour of the tinzaparin group (95% confidence interval -1.94 to -1.62). Participants treated with tinzaparin had statistically significantly fewer hospitalisation days than participants in the group treated with placebo, with a mean difference of -4.98 days (95% confidence interval -5.48 to -4.48). Two minor bleeding events were reported as adverse events in the tinzaparin group, and none were reported in the placebo group. The second study (unclear risk of bias) including 34 participants and was a conference abstract with limited data and only addressed one of the predefined outcomes of the review; i.e. pain intensity. After one day pain intensity reduced more, as reported on a visual analogue scale, in the dalteparin group than in the placebo group, mean difference -1.30 (95% confidence interval -1.60 to -1.00), with the quality of evidence rated very low. The most important reasons for downgrading the quality of evidence were serious risk of bias and imprecision (due to low sample size or low occurrence of events). AUTHORS' CONCLUSIONS Based on the results of two studies, evidence is incomplete to support or refute the effectiveness of low-molecular-weight heparins in people with sickle cell disease. Vaso-occlusive crises are extremely debilitating for sufferers of sickle cell disease; therefore well-designed placebo-controlled studies with other types of low-molecular-weight heparins, and in participants with different genotypes of sickle cell disease, still need to be carried out to confirm or dismiss the results of this single study.
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Affiliation(s)
- Esther J van Zuuren
- Department of Dermatology, Leiden University Medical Center, PO Box 9600, B1-Q, Leiden, Netherlands, 2300 RC
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Hemopexin therapy reverts heme-induced proinflammatory phenotypic switching of macrophages in a mouse model of sickle cell disease. Blood 2015; 127:473-86. [PMID: 26675351 DOI: 10.1182/blood-2015-08-663245] [Citation(s) in RCA: 200] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 12/11/2015] [Indexed: 02/07/2023] Open
Abstract
Hemolytic diseases, such as sickle cell anemia and thalassemia, are characterized by enhanced release of hemoglobin and heme into the circulation, heme-iron loading of reticulo-endothelial system macrophages, and chronic inflammation. Here we show that in addition to activating the vascular endothelium, hemoglobin and heme excess alters the macrophage phenotype in sickle cell disease. We demonstrate that exposure of cultured macrophages to hemolytic aged red blood cells, heme, or iron causes their functional phenotypic change toward a proinflammatory state. In addition, hemolysis and macrophage heme/iron accumulation in a mouse model of sickle disease trigger similar proinflammatory phenotypic alterations in hepatic macrophages. On the mechanistic level, this critically depends on reactive oxygen species production and activation of the Toll-like receptor 4 signaling pathway. We further demonstrate that the heme scavenger hemopexin protects reticulo-endothelial macrophages from heme overload in heme-loaded Hx-null mice and reduces production of cytokines and reactive oxygen species. Importantly, in sickle mice, the administration of human exogenous hemopexin attenuates the inflammatory phenotype of macrophages. Taken together, our data suggest that therapeutic administration of hemopexin is beneficial to counteract heme-driven macrophage-mediated inflammation and its pathophysiologic consequences in sickle cell disease.
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Xu GG, Deshpande TM, Ghatge MS, Mehta AY, Omar ASM, Ahmed MH, Venitz J, Abdulmalik O, Zhang Y, Safo MK. Design, Synthesis, and Investigation of Novel Nitric Oxide (NO)-Releasing Prodrugs as Drug Candidates for the Treatment of Ischemic Disorders: Insights into NO-Releasing Prodrug Biotransformation and Hemoglobin-NO Biochemistry. Biochemistry 2015; 54:7178-92. [PMID: 26582149 DOI: 10.1021/acs.biochem.5b01074] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We have developed novel nitric oxide (NO)-releasing prodrugs of efaproxiral (RSR13) for their potential therapeutic applications in a variety of diseases with underlying ischemia. RSR13 is an allosteric effector of hemoglobin (Hb) that decreases the protein's affinity for oxygen, thereby increasing tissue oxygenation. NO, because of its vasodilatory property, in the form of ester prodrugs has been found to be useful in managing several cardiovascular diseases by increasing blood flow and oxygenation in ischemic tissues. We synthesized three NO-donor ester derivatives of RSR13 (DD-1, DD-2, and DD-3) by attaching the NO-releasing moieties nitrooxyethyl, nitrooxypropyl, and 1-(pyrrolidin-1-yl)diazen-1-ium-1,2-diolate, respectively, to the carboxylate of RSR13. In vitro studies demonstrated that the compounds released NO in a time-dependent manner upon being incubated with l-cysteine (1.8-9.3%) or human serum (2.3-52.5%) and also reduced the affinity of Hb for oxygen in whole blood (ΔP50 of 4.9-21.7 mmHg vs ΔP50 of 25.4-32.1 mmHg for RSR13). Crystallographic studies showed RSR13, the hydrolysis product of the reaction between DD-1 and deoxygenated Hb, bound to the central water cavity of Hb. Also, the hydrolysis product, NO, was observed exclusively bound to the two α hemes, the first such HbNO structure to be reported, capturing the previously proposed physiological bis-ligated nitrosylHb species. Finally, nitrate was observed bound to βHis97. Ultraperformance liquid chromatography-mass spectrometry analysis of the compounds incubated with matrices used for the various studies demonstrated the presence of the predicted reaction products. Our findings, beyond the potential therapeutic application, provide valuable insights into the biotransformation of NO-releasing prodrugs and their mechanism of action and into hemoglobin-NO biochemistry at the molecular level.
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Affiliation(s)
| | | | | | | | - Abdel Sattar M Omar
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University , Alsulaymanyah, Jeddah 21589, Saudi Arabia.,Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Al-Azhar University , Cairo 11884, Egypt
| | | | | | - Osheiza Abdulmalik
- Division of Hematology, The Children's Hospital of Philadelphia , Philadelphia, Pennsylvania 19104, United States
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Bacterial Infections Following Splenectomy for Malignant and Nonmalignant Hematologic Diseases. Mediterr J Hematol Infect Dis 2015; 7:e2015057. [PMID: 26543526 PMCID: PMC4621170 DOI: 10.4084/mjhid.2015.057] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 10/03/2015] [Indexed: 01/19/2023] Open
Abstract
Splenectomy, while often necessary in otherwise healthy patients after major trauma, finds its primary indication for patients with underlying malignant or nonmalignant hematologic diseases. Indications of splenectomy for hematologic diseases have been reducing in the last few years, due to improved diagnostic and therapeutic tools. In high-income countries, there is a clear decrease over calendar time in the incidence of all indication splenectomy except nonmalignant hematologic diseases. However, splenectomy, even if with different modalities including laparoscopic splenectomy and partial splenectomy, continue to be a current surgical practice both in nonmalignant hematologic diseases, such as Immune Thrombocytopenic Purpura (ITP), Autoimmune Hemolytic Anemia (AIHA), Congenital Hemolytic Anemia such as Spherocytosis, Sickle Cell Anemia and Thalassemia and Malignant Hematological Disease, such as lymphoma. Today millions of people in the world are splenectomized. Splenectomy, independently of its cause, induces an early and late increase in the incidence of venous thromboembolism and infections. Infections remain the most dangerous complication of splenectomy. After splenectomy, the levels of antibody are preserved but there is a loss of memory B cells against pneumococcus and tetanus, and the loss of marginal zone monocytes deputed to immunological defense from capsulated bacteria. Commonly, the infections strictly correlated to the absence of the spleen or a decreased or absent splenic function are due to encapsulated bacteria that are the most virulent pathogens in this set of patients. Vaccination with polysaccharide and conjugate vaccines again Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis should be performed before the splenectomy. This practice reduces but does not eliminate the occurrence of overwhelming infections due to capsulated bacteria. At present, most of infections found in splenectomized patients are due to Gram-negative (G-) bacteria. The underlying disease is the most important factor in determining the frequency and severity of infections. So, splenectomy for malignant diseases has the major risk of infections.
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Omar AM, Mahran MA, Ghatge MS, Chowdhury N, Bamane FHA, El-Araby ME, Abdulmalik O, Safo MK. Identification of a novel class of covalent modifiers of hemoglobin as potential antisickling agents. Org Biomol Chem 2015; 13:6353-70. [PMID: 25974708 DOI: 10.1039/c5ob00367a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Aromatic aldehydes and ethacrynic acid (ECA) exhibit antipolymerization properties that are beneficial for sickle cell disease therapy. Based on the ECA pharmacophore and its atomic interaction with hemoglobin, we designed and synthesized several compounds - designated as KAUS (imidazolylacryloyl derivatives) - that we hypothesized would bind covalently to βCys93 of hemoglobin and inhibit sickling. The compounds surprisingly showed weak allosteric and antisickling properties. X-ray studies of hemoglobin in complex with representative KAUS compounds revealed an unanticipated mode of Michael addition between the β-unsaturated carbon and the N-terminal αVal1 nitrogen at the α-cleft of hemoglobin, with no observable interaction with βCys93. Interestingly, the compounds exhibited almost no reactivity with the free amino acids, L-Val, L-His and L-Lys, but showed some reactivity with both glutathione and L-Cys. Our findings provide a molecular level explanation for the compounds biological activities and an important framework for targeted modifications that would yield novel potent antisickling agents.
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Affiliation(s)
- A M Omar
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Alsulaymanyah, Jeddah 21589, Saudi Arabia.
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Adewoyin AS. Management of sickle cell disease: a review for physician education in Nigeria (sub-saharan Africa). Anemia 2015; 2015:791498. [PMID: 25667774 PMCID: PMC4312619 DOI: 10.1155/2015/791498] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 11/18/2014] [Accepted: 12/17/2014] [Indexed: 11/27/2022] Open
Abstract
Sickle cell disease (SCD) predominates in sub-Saharan Africa, East Mediterranean areas, Middle East, and India. Nigeria, being the most populous black nation in the world, bears its greatest burden in sub-Saharan Africa. The last few decades have witnessed remarkable scientific progress in the understanding of the complex pathophysiology of the disease. Improved clinical insights have heralded development and establishment of disease modifying interventions such as chronic blood transfusions, hydroxyurea therapy, and haemopoietic stem cell transplantation. Coupled with parallel improvements in general supportive, symptomatic, and preventive measures, current evidence reveals remarkable appreciation in quality of life among affected individuals in developed nations. Currently, in Nigeria and other West African states, treatment and control of SCD are largely suboptimal. Improved knowledge regarding SCD phenotypes and its comprehensive care among Nigerian physicians will enhance quality of care for affected persons. This paper therefore provides a review on the aetiopathogenesis, clinical manifestations, and management of SCD in Nigeria, with a focus on its local patterns and peculiarities. Established treatment guidelines as appropriate in the Nigerian setting are proffered, as well as recommendations for improving care of affected persons.
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Affiliation(s)
- Ademola Samson Adewoyin
- Department of Haematology and Blood Transfusion, University of Benin Teaching Hospital, PMB 1111, Benin City, Edo State, Nigeria
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