1
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Leonard AK, Furstenau D, Inam Z, Luckett C, Chu R, Demirci S, Essawi K, Gudmundsdottir B, Hinds M, DiNicola J, Li Q, Eaton WA, Cellmer T, Wang X, Thein SL, Macari ER, VanNest S, Hsieh MM, Bonner M, Pierciey FJ, Tisdale JF. In vivo measurement of RBC survival in patients with sickle cell disease before or after hematopoietic stem cell transplantation. Blood Adv 2024; 8:1806-1816. [PMID: 38181784 PMCID: PMC11006808 DOI: 10.1182/bloodadvances.2023011397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 10/17/2023] [Accepted: 11/11/2023] [Indexed: 01/07/2024] Open
Abstract
ABSTRACT Stable, mixed-donor-recipient chimerism after allogeneic hematopoietic stem cell transplantation (HSCT) for patients with sickle cell disease (SCD) is sufficient for phenotypic disease reversal, and results from differences in donor/recipient-red blood cell (RBC) survival. Understanding variability and predictors of RBC survival among patients with SCD before and after HSCT is critical for gene therapy research which seeks to generate sufficient corrected hemoglobin to reduce polymerization thereby overcoming the red cell pathology of SCD. This study used biotin labeling of RBCs to determine the lifespan of RBCs in patients with SCD compared with patients who have successfully undergone curative HSCT, participants with sickle cell trait (HbAS), and healthy (HbAA) donors. Twenty participants were included in the analysis (SCD pre-HSCT: N = 6, SCD post-HSCT: N = 5, HbAS: N = 6, and HbAA: N = 3). The average RBC lifespan was significantly shorter for participants with SCD pre-HSCT (64.1 days; range, 35-91) compared with those with SCD post-HSCT (113.4 days; range, 105-119), HbAS (126.0 days; range, 119-147), and HbAA (123.7 days; range, 91-147) (P<.001). RBC lifespan correlated with various hematologic parameters and strongly correlated with the average final fraction of sickled RBCs after deoxygenation (P<.001). No adverse events were attributable to the use of biotin and related procedures. Biotin labeling of RBCs is a safe and feasible methodology to evaluate RBC survival in patients with SCD before and after HSCT. Understanding differences in RBC survival may ultimately guide gene therapy protocols to determine hemoglobin composition required to reverse the SCD phenotype as it relates directly to RBC survival. This trial was registered at www.clinicaltrials.gov as #NCT04476277.
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Affiliation(s)
- Alexis K. Leonard
- Cellular and Molecular Therapeutics Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD
- Department of Hematology, St. Jude Children’s Research Hospital, Memphis, TN
| | - Dana Furstenau
- Cellular and Molecular Therapeutics Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD
- Department of Pediatrics, Division of Hematology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Zaina Inam
- Cellular and Molecular Therapeutics Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD
- Center for Cancer and Blood Disorders, Children’s National Hospital, Washington, DC
| | - Christina Luckett
- Cellular and Molecular Therapeutics Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Rebecca Chu
- Cellular and Molecular Therapeutics Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Selami Demirci
- Cellular and Molecular Therapeutics Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Khaled Essawi
- Department of Medical Laboratory Technology, College of Applied Medical Sciences, Jazan University, Gizan, Saudi Arabia
| | - Bjorg Gudmundsdottir
- Cellular and Molecular Therapeutics Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Malikiya Hinds
- Cellular and Molecular Therapeutics Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Julia DiNicola
- Cellular and Molecular Therapeutics Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Quan Li
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD
| | - William A. Eaton
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD
| | - Troy Cellmer
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD
| | - Xunde Wang
- Sickle Cell Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Swee Lay Thein
- Sickle Cell Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | | | | | - Matthew M. Hsieh
- Cellular and Molecular Therapeutics Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD
| | | | | | - John F. Tisdale
- Cellular and Molecular Therapeutics Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD
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2
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Xu JZ, Conrey A, Frey I, Gwaabe E, Menapace LA, Tumburu L, Lundt M, Lequang T, Li Q, Glass K, Dunkelberger EB, Iyer V, Mangus H, Kung C, Dang L, Kosinski PA, Hawkins P, Jeffries N, Eaton WA, Lay Thein S. A phase 1 dose escalation study of the pyruvate kinase activator mitapivat (AG-348) in sickle cell disease. Blood 2022; 140:2053-2062. [PMID: 35576529 PMCID: PMC9837441 DOI: 10.1182/blood.2022015403] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 05/11/2022] [Indexed: 01/21/2023] Open
Abstract
Polymerization of deoxygenated hemoglobin S underlies the pathophysiology of sickle cell disease (SCD). In activating red blood cell pyruvate kinase and glycolysis, mitapivat (AG-348) increases adenosine triphosphate (ATP) levels and decreases the 2,3-diphosphoglycerate (2,3-DPG) concentration, an upstream precursor in glycolysis. Both changes have therapeutic potential for patients with SCD. Here, we evaluated the safety and tolerability of multiple ascending doses of mitapivat in adults with SCD with no recent blood transfusions or changes in hydroxyurea or l-glutamine therapy. Seventeen subjects were enrolled; 1 subject was withdrawn shortly after starting the study. Sixteen subjects completed 3 ascending dose levels of mitapivat (5, 20, and 50 mg, twice daily [BID]) for 2 weeks each; following a protocol amendment, the dose was escalated to 100 mg BID in 9 subjects. Mitapivat was well tolerated at all dose levels, with the most common treatment-emergent adverse events (AEs) being insomnia, headache, and hypertension. Six serious AEs (SAEs) included 4 vaso-occlusive crises (VOCs), non-VOC-related shoulder pain, and a preexisting pulmonary embolism. Two VOCs occurred during drug taper and were possibly drug related; no other SAEs were drug related. Mean hemoglobin increase at the 50 mg BID dose level was 1.2 g/dL, with 9 of 16 (56.3%) patients achieving a hemoglobin response of a ≥1 g/dL increase compared with baseline. Mean reductions in hemolytic markers and dose-dependent decreases in 2,3-DPG and increases in ATP were also observed. This study provides proof of concept that mitapivat has disease-modifying potential in patients with SCD. This trial was registered at www.clinicaltrials.gov as #NCT04000165.
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Affiliation(s)
- Julia Z. Xu
- Sickle Cell Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Anna Conrey
- Sickle Cell Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Ingrid Frey
- Sickle Cell Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Eveline Gwaabe
- Sickle Cell Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Laurel A. Menapace
- Sickle Cell Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Laxminath Tumburu
- Sickle Cell Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Maureen Lundt
- Sickle Cell Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Timothy Lequang
- Sickle Cell Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Quan Li
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD
| | - Kristen Glass
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD
| | - Emily B. Dunkelberger
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD
| | | | | | | | - Lenny Dang
- Agios Pharmaceuticals, Inc., Cambridge, MA
| | | | | | - Neal Jeffries
- Office of Biostatistics Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | - William A. Eaton
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD
| | - Swee Lay Thein
- Sickle Cell Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
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3
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Eaton WA. Drug discovery by a basic research scientist. Front Mol Biosci 2022; 9:1062346. [DOI: 10.3389/fmolb.2022.1062346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 10/20/2022] [Indexed: 11/06/2022] Open
Abstract
I was fortunate to do my military service during the Vietnam era as a medical officer at the National Institutes of Health (NIH) in Bethesda, Maryland. My first research at NIH was concerned with making a variety of optical measurements on nucleic acid bases and proteins, including single crystal spectra in linearly polarized light and near infrared circular dichroism, interpreting the spectra using molecular orbital and crystal field theories. What I do now is drug discovery, a field at the opposite end of the scientific spectrum. This article gives a brief account of my transition from spectroscopy to sickle cell hemoglobin polymerization to protein folding to drug discovery for treating sickle cell disease. My lab recently developed a high throughput assay to screen the 12,657 compounds of the California Institute of Biomedical Research ReFrame drug repurposing library. This is a precious library because the compounds have either been FDA approved or have been tested in clinical trials. Since the 1970s numerous agents have been reported in the literature to inhibit HbS polymerization and/or sickling with only one successful drug, hydroxyurea, and another of dubious value, voxelotor, even though it has been approved by the FDA. Our screen has discovered 106 anti-sickling agents in the ReFrame compound library. We estimate that as many as 21 of these compounds could become oral drugs for treating sickle cell disease because they inhibit at concentrations typical of the free concentrations of oral drugs in human serum.
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4
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Phenotypic screening of the ReFRAME drug repurposing library to discover new drugs for treating sickle cell disease. Proc Natl Acad Sci U S A 2022; 119:e2210779119. [PMID: 36161945 PMCID: PMC9546543 DOI: 10.1073/pnas.2210779119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Stem cell transplantation and genetic therapies offer potential cures for patients with sickle cell disease (SCD), but these options require advanced medical facilities and are expensive. Consequently, these treatments will not be available for many years to the majority of patients suffering from this disease. What is urgently needed now is an inexpensive oral drug in addition to hydroxyurea, the only drug approved by the FDA that inhibits sickle-hemoglobin polymerization. Here, we report the results of the first phase of our phenotypic screen of the 12,657 compounds of the Scripps ReFRAME drug repurposing library using a recently developed high-throughput assay to measure sickling times following deoxygenation to 0% oxygen of red cells from sickle trait individuals. The ReFRAME library is a very important collection because the compounds are either FDA-approved drugs or have been tested in clinical trials. From dose-response measurements, 106 of the 12,657 compounds exhibit statistically significant antisickling at concentrations ranging from 31 nM to 10 μM. Compounds that inhibit sickling of trait cells are also effective with SCD cells. As many as 21 of the 106 antisickling compounds emerge as potential drugs. This estimate is based on a comparison of inhibitory concentrations with free concentrations of oral drugs in human serum. Moreover, the expected therapeutic potential for each level of inhibition can be predicted from measurements of sickling times for cells from individuals with sickle syndromes of varying severity. Our results should motivate others to develop one or more of these 106 compounds into drugs for treating SCD.
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5
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Vunnam N, Hansen S, Williams DC, Been M, Lo CH, Pandey AK, Paulson CN, Rohde JA, Thomas DD, Sachs JN, Wood DK. Fluorescence Lifetime Measurement of Prefibrillar Sickle Hemoglobin Oligomers as a Platform for Drug Discovery in Sickle Cell Disease. Biomacromolecules 2022; 23:3822-3830. [PMID: 35944154 PMCID: PMC9472799 DOI: 10.1021/acs.biomac.2c00671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 07/22/2022] [Indexed: 11/30/2022]
Abstract
The molecular origin of sickle cell disease (SCD) has been known since 1949, but treatments remain limited. We present the first high-throughput screening (HTS) platform for discovering small molecules that directly inhibit sickle hemoglobin (HbS) oligomerization and improve blood flow, potentially overcoming a long-standing bottleneck in SCD drug discovery. We show that at concentrations far below the threshold for nucleation and rapid polymerization, deoxygenated HbS forms small assemblies of multiple α2β2 tetramers. Our HTS platform leverages high-sensitivity fluorescence lifetime measurements that monitor these temporally stable prefibrillar HbS oligomers. We show that this approach is sensitive to compounds that inhibit HbS polymerization with or without modulating hemoglobin oxygen binding affinity. We also report the results of a pilot small-molecule screen in which we discovered and validated several novel inhibitors of HbS oligomerization.
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Affiliation(s)
- Nagamani Vunnam
- Department
of Biomedical Engineering, University of
Minnesota, Minneapolis, Minnesota 55455, United States
| | - Scott Hansen
- Department
of Biomedical Engineering, University of
Minnesota, Minneapolis, Minnesota 55455, United States
| | - Dillon C. Williams
- Department
of Biomedical Engineering, University of
Minnesota, Minneapolis, Minnesota 55455, United States
| | - MaryJane
Olivia Been
- Department
of Biomedical Engineering, University of
Minnesota, Minneapolis, Minnesota 55455, United States
| | - Chih Hung Lo
- Department
of Biomedical Engineering, University of
Minnesota, Minneapolis, Minnesota 55455, United States
| | - Anil K. Pandey
- Department
of Biomedical Engineering, University of
Minnesota, Minneapolis, Minnesota 55455, United States
| | - Carolyn N. Paulson
- Department
of Biomedical Engineering, University of
Minnesota, Minneapolis, Minnesota 55455, United States
| | - John A. Rohde
- Department
of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - David D. Thomas
- Department
of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Jonathan N. Sachs
- Department
of Biomedical Engineering, University of
Minnesota, Minneapolis, Minnesota 55455, United States
| | - David K. Wood
- Department
of Biomedical Engineering, University of
Minnesota, Minneapolis, Minnesota 55455, United States
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6
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Quezado ZMN, Kamimura S, Smith M, Wang X, Heaven MR, Jana S, Vogel S, Zerfas P, Combs CA, Almeida LEF, Li Q, Quezado M, Horkayne-Szakaly I, Kosinski PA, Yu S, Kapadnis U, Kung C, Dang L, Wakim P, Eaton WA, Alayash AI, Thein SL. Mitapivat increases ATP and decreases oxidative stress and erythrocyte mitochondria retention in a SCD mouse model. Blood Cells Mol Dis 2022; 95:102660. [PMID: 35366607 DOI: 10.1016/j.bcmd.2022.102660] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 03/08/2022] [Accepted: 03/09/2022] [Indexed: 11/25/2022]
Abstract
Polymerization of deoxygenated sickle hemoglobin (HbS) leads to erythrocyte sickling. Enhancing activity of the erythrocyte glycolytic pathway has anti-sickling potential as this reduces 2,3-diphosphoglycerate (2,3-DPG) and increases ATP, factors that decrease HbS polymerization and improve erythrocyte membrane integrity. These factors can be modulated by mitapivat, which activates erythrocyte pyruvate kinase (PKR) and improves sickling kinetics in SCD patients. We investigated mechanisms by which mitapivat may impact SCD by examining its effects in the Townes SCD mouse model. Control (HbAA) and sickle (HbSS) mice were treated with mitapivat or vehicle. Surprisingly, HbSS had higher PKR protein, higher ATP, and lower 2,3-DPG levels, compared to HbAA mice, in contrast with humans with SCD, in whom 2,3-DPG is elevated compared to healthy subjects. Despite our inability to investigate 2,3-DPG-mediated sickling and hemoglobin effects, mitapivat yielded potential benefits in HbSS mice. Mitapivat further increased ATP without significantly changing 2,3-DPG or hemoglobin levels, and decreased levels of leukocytosis, erythrocyte oxidative stress, and the percentage of erythrocytes that retained mitochondria in HbSS mice. These data suggest that, even though Townes HbSS mice have increased PKR activity, further activation of PKR with mitapivat yields potentially beneficial effects that are independent of changes in sickling or hemoglobin levels.
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Affiliation(s)
- Zenaide M N Quezado
- Department of Perioperative Medicine, National Institutes of Health Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA; Sickle Cell Branch, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Sayuri Kamimura
- Department of Perioperative Medicine, National Institutes of Health Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA
| | - Meghann Smith
- Department of Perioperative Medicine, National Institutes of Health Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA
| | - Xunde Wang
- Sickle Cell Branch, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Michael R Heaven
- Laboratory of Biochemistry and Vascular Biology, Center for Biologics Evaluation and Research, Food and Drug Administration (FDA), Silver Spring, MD 20993, USA
| | - Sirsendu Jana
- Laboratory of Biochemistry and Vascular Biology, Center for Biologics Evaluation and Research, Food and Drug Administration (FDA), Silver Spring, MD 20993, USA
| | - Sebastian Vogel
- Department of Perioperative Medicine, National Institutes of Health Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA
| | - Patricia Zerfas
- Office of Research Services, Office of the Director, National Institutes of Health, Bethesda, MD 20892, USA
| | - Christian A Combs
- Light Microscopy Core, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Luis E F Almeida
- Department of Perioperative Medicine, National Institutes of Health Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA
| | - Quan Li
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Martha Quezado
- Laboratory of Pathology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Iren Horkayne-Szakaly
- Neuropathology and Ophthalmic Pathology, Joint Pathology Center, Defense Health Agency, Silver Spring, MD 20910, USA
| | | | - Shaoxia Yu
- Agios Pharmaceuticals Inc, Cambridge, MA 02139, USA
| | | | - Charles Kung
- Agios Pharmaceuticals Inc, Cambridge, MA 02139, USA
| | - Lenny Dang
- Agios Pharmaceuticals Inc, Cambridge, MA 02139, USA
| | - Paul Wakim
- Biostatistics and Clinical Epidemiology Service, National Institutes of Health Clinical Center, Bethesda, MD 20892, USA
| | - William A Eaton
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Abdu I Alayash
- Laboratory of Biochemistry and Vascular Biology, Center for Biologics Evaluation and Research, Food and Drug Administration (FDA), Silver Spring, MD 20993, USA
| | - Swee Lay Thein
- Sickle Cell Branch, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
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7
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Nakagawa A, Cooper MK, Kost-Alimova M, Berstler J, Yu B, Berra L, Klings ES, Huang MS, Heeney MM, Bloch DB, Zapol WM. High-Throughput Assay to Screen Small Molecules for Their Ability to Prevent Sickling of Red Blood Cells. ACS OMEGA 2022; 7:14009-14016. [PMID: 35559170 PMCID: PMC9089379 DOI: 10.1021/acsomega.2c00541] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 04/06/2022] [Indexed: 06/15/2023]
Abstract
Sickle cell disease (SCD) is an inherited disorder of hemoglobin (Hb); approximately 300,000 babies are born worldwide with SCD each year. In SCD, fibers of polymerized sickle Hb (HbS) form in red blood cells (RBCs), which cause RBCs to develop their characteristic "sickled" shape, resulting in hemolytic anemia and numerous vascular complications including vaso-occlusive crises. The development of novel antisickling compounds will provide new therapeutic options for patients with SCD. We developed a high-throughput "sickling assay" that is based on an automated high-content imaging system to quantify the effects of hypoxia on the shape and size of RBCs from HbSS SCD patients (SS RBCs). We used this assay to screen thousands of compounds for their ability to inhibit sickling. In the assay, voxelotor (an FDA-approved medication used to treat SCD) prevented sickling with a z'-factor > 0.4, suggesting that the assay is capable of identifying compounds that inhibit sickling. We screened the Broad Repurposing Library of 5393 compounds for their ability to prevent sickling in 4% oxygen/96% nitrogen. We identified two compounds, SNS-314 mesylate and voxelotor itself, that successfully prevented sickling. SNS-314 mesylate prevented sickling in the absence of oxygen, while voxelotor did not, suggesting that SNS-314 mesylate acts by a mechanism that is different from that of voxelotor. The sickling assay described in this study will permit the identification of additional, novel antisickling compounds, which will potentially expand the therapeutic options for SCD.
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Affiliation(s)
- Akito Nakagawa
- Anesthesia
Center for Critical Care Research, Department of Anesthesia, Critical
Care, and Pain Medicine, Massachusetts General
Hospital and Harvard Medical School, Boston, Massachusetts 02114, United States
| | - Marissa K. Cooper
- Anesthesia
Center for Critical Care Research, Department of Anesthesia, Critical
Care, and Pain Medicine, Massachusetts General
Hospital and Harvard Medical School, Boston, Massachusetts 02114, United States
| | - Maria Kost-Alimova
- Center
for the Development of Therapeutics, Broad
Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
| | - James Berstler
- Center
for the Development of Therapeutics, Broad
Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
| | - Binglan Yu
- Anesthesia
Center for Critical Care Research, Department of Anesthesia, Critical
Care, and Pain Medicine, Massachusetts General
Hospital and Harvard Medical School, Boston, Massachusetts 02114, United States
| | - Lorenzo Berra
- Anesthesia
Center for Critical Care Research, Department of Anesthesia, Critical
Care, and Pain Medicine, Massachusetts General
Hospital and Harvard Medical School, Boston, Massachusetts 02114, United States
| | - Elizabeth S. Klings
- Pulmonary
Center, Boston University School of Medicine, Boston, Massachusetts 02118, United States
| | - Mary S. Huang
- Division
of Pediatric Hematology and Oncology, Massachusetts
General Hospital and Harvard Medical School, Boston, Massachusetts 02114, United States
| | - Matthew M. Heeney
- Division
of Hematology/Oncology, Boston Children’s
Hospital and Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Donald B. Bloch
- Anesthesia
Center for Critical Care Research, Department of Anesthesia, Critical
Care, and Pain Medicine, Massachusetts General
Hospital and Harvard Medical School, Boston, Massachusetts 02114, United States
- Division
of Rheumatology, Allergy and Immunology, Department of Medicine, Massachusetts General Hospital and Harvard Medical
School, Boston, Massachusetts 02114, United States
| | - Warren M. Zapol
- Anesthesia
Center for Critical Care Research, Department of Anesthesia, Critical
Care, and Pain Medicine, Massachusetts General
Hospital and Harvard Medical School, Boston, Massachusetts 02114, United States
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8
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Eaton WA. Impact of hemoglobin biophysical studies on molecular pathogenesis and drug therapy for sickle cell disease. Mol Aspects Med 2021; 84:100971. [PMID: 34274158 DOI: 10.1016/j.mam.2021.100971] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Accepted: 05/26/2021] [Indexed: 01/20/2023]
Abstract
Basic research on hemoglobin has been essential for understanding the origin and treatment of many hematological disorders due to abnormal hemoglobins. The most important of the hemoglobinopathies is sickle cell disease - Linus Pauling's "molecular disease" that gave birth to molecular medicine. In this review, I will describe the contributions of basic biophysical research on normal and sickle cell hemoglobin (HbS) to understanding the molecular pathogenesis of the disease and providing the conceptual basis for the various approaches to drug therapy that target HbS polymerization. Most prominent among these are the experimental results on the solubility of HbS as a function of oxygen saturation explained by the allosteric model of Monod, Wyman, and Changeux and the Gill-Wyman thermodynamic linkage relation between solubility and oxygen binding, the solubility of mixtures of HbS with normal or fetal hemoglobin explained by Minton's thermodynamic model, and the highly unusual kinetics of HbS polymerization explained by a novel double nucleation mechanism that also accounts for the aggregation kinetics of the Alzheimer's peptide. The HbS polymerization kinetics are of great importance to understanding the pathophysiology and clinical course, as well as guiding drug development for treating this common and severe disease. The article focuses primarily on experimental and theoretical results from my lab, so it is not a comprehensive review of the subject.
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Affiliation(s)
- William A Eaton
- Laboratory of Chemical Physics, 5/104, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA.
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9
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Treatment of sickle cell disease by increasing oxygen affinity of hemoglobin. Blood 2021; 138:1172-1181. [PMID: 34197597 DOI: 10.1182/blood.2021012070] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 06/30/2021] [Indexed: 11/20/2022] Open
Abstract
The issue of treating sickle cell disease with drugs that increase hemoglobin oxygen affinity has come to the fore with the FDA approval in 2019 of voxelotor, the only anti-sickling drug approved since hydroxyurea in 1998. Voxelotor reduces sickling by increasing the concentration of the non-polymerizing, high oxygen affinity R (oxy) conformation of HbS. Treatment of sickle cell patients with voxelotor increases Hb levels and decreases indicators of hemolysis, but with no indication as yet that it reduces the frequency of pain episodes. Here we use the allosteric model of Monod, Wyman, and Changeux to simulate whole blood oxygen dissociation curves and red cell sickling in the absence and presence of voxelotor under the in vivo conditions of rapid oxygen pressure decreases. Our modeling agrees with experiments using a new robust assay, which shows the very large, expected decrease in sickling from the drug. The modeling indicates, however, that the increase in oxygen delivery from reduced sickling is largely offset by the increase in oxygen affinity. The net result is that the drug increases overall oxygen delivery only at the very lowest oxygen pressures. Reduction of sickling does, however, mitigate against red cell damage and explains the observed decrease in hemolysis. More importantly, our modeling of in vivo oxygen dissociation, sickling, and oxygen delivery suggests that drugs that increase fetal hemoglobin or decrease MCHC, should be more therapeutically effective than drugs that increase oxygen affinity.
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10
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Allosteric control of hemoglobin S fiber formation by oxygen and its relation to the pathophysiology of sickle cell disease. Proc Natl Acad Sci U S A 2020; 117:15018-15027. [PMID: 32527859 PMCID: PMC7334536 DOI: 10.1073/pnas.1922004117] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The pathology of sickle cell disease is caused by polymerization of the abnormal hemoglobin S upon deoxygenation in the tissues to form fibers in red cells, causing them to deform and occlude the circulation. Drugs that allosterically shift the quaternary equilibrium from the polymerizing T quaternary structure to the nonpolymerizing R quaternary structure are now being developed. Here we update our understanding on the allosteric control of fiber formation at equilibrium by showing how the simplest extension of the classic quaternary two-state allosteric model of Monod, Wyman, and Changeux to include tertiary conformational changes provides a better quantitative description. We also show that if fiber formation is at equilibrium in vivo, the vast majority of cells in most tissues would contain fibers, indicating that it is unlikely that the disease would be survivable once the nonpolymerizing fetal hemoglobin has been replaced by adult hemoglobin S at about 1 y after birth. Calculations of sickling times, based on a recently discovered universal relation between the delay time prior to fiber formation and supersaturation, show that in vivo fiber formation is very far from equilibrium. Our analysis indicates that patients survive because the delay period allows the majority of cells to escape the small vessels of the tissues before fibers form. The enormous sensitivity of the duration of the delay period to intracellular hemoglobin composition also explains why sickle trait, the heterozygous condition, and the compound heterozygous condition of hemoglobin S with pancellular hereditary persistence of fetal hemoglobin are both relatively benign conditions.
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Demirci S, Gudmundsdottir B, Li Q, Haro-Mora JJ, Nassehi T, Drysdale C, Yapundich M, Gamer J, Seifuddin F, Tisdale JF, Uchida N. βT87Q-Globin Gene Therapy Reduces Sickle Hemoglobin Production, Allowing for Ex Vivo Anti-sickling Activity in Human Erythroid Cells. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 17:912-921. [PMID: 32405513 PMCID: PMC7210457 DOI: 10.1016/j.omtm.2020.04.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 04/13/2020] [Indexed: 12/31/2022]
Abstract
Lentiviral addition of βT87Q-globin, a modified β-globin with an anti-sickling mutation, is currently being used in gene therapy trials for sickle cell disease (SCD) and β-thalassemia patients. βT87Q-globin interferes with sickle hemoglobin (HbS) polymerization. Here, we generated the SCD mutation in an immortalized human erythroid cell line (HUDEP-2) to investigate the anti-sickling activity of βT87Q-globin. Sickle HUDEP-2 (sHUDEP-2) cells produced robust HbS after differentiation and sickled under deoxygenated conditions, comparable with SCD CD34+ progeny. Lentiviral transduction provided 9.5–26.8 pg/cell βT87Q-globin (R2 = 0.83) in a vector copy number (VCN)-dependent manner, resulting in a significant reduction of sickling ratios (R2 = 0.92). Interestingly, βT87Q-globin transduction markedly reduced endogenous βS-globin (R2 = 0.84) to an undetectable level (0.4–16.8 pg/cell) in sHUDEP-2 cells, as well as endogenous β-globin in human CD34+ cell-derived erythroid cells. RNA sequencing (RNA-seq) analysis with βT87Q-transduced sHUDEP-2 and human CD34+-derived cells revealed activation of inflammation- and proliferation-related programs, suggesting minimal changes in background gene expression except for βT87Q-globin expression and endogenous β/βS-globin suppression. In summary, using sHUDEP-2 and CD34+-derived cells, we demonstrated that lentiviral addition of βT87Q-globin strongly reduced endogenous β-/βS-globin expression, resulting in an anti-sickling effect. Our findings should be helpful to understand the anti-sickling effects of therapeutic genes in SCD gene therapy.
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Affiliation(s)
- Selami Demirci
- Cellular and Molecular Therapeutics Branch, National Heart Lung and Blood Institutes (NHLBI)/National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Bjorg Gudmundsdottir
- Cellular and Molecular Therapeutics Branch, National Heart Lung and Blood Institutes (NHLBI)/National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Quan Li
- Laboratory of Chemical Physics, NIDDK, NIH, Bethesda, MD, USA
| | - Juan J Haro-Mora
- Cellular and Molecular Therapeutics Branch, National Heart Lung and Blood Institutes (NHLBI)/National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Tina Nassehi
- Cellular and Molecular Therapeutics Branch, National Heart Lung and Blood Institutes (NHLBI)/National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Claire Drysdale
- Cellular and Molecular Therapeutics Branch, National Heart Lung and Blood Institutes (NHLBI)/National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Morgan Yapundich
- Cellular and Molecular Therapeutics Branch, National Heart Lung and Blood Institutes (NHLBI)/National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Jackson Gamer
- Cellular and Molecular Therapeutics Branch, National Heart Lung and Blood Institutes (NHLBI)/National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Fayaz Seifuddin
- Bioinformatics and Computational Biology Laboratory, NHLBI, NIH, Bethesda, MD, USA
| | - John F Tisdale
- Cellular and Molecular Therapeutics Branch, National Heart Lung and Blood Institutes (NHLBI)/National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Naoya Uchida
- Cellular and Molecular Therapeutics Branch, National Heart Lung and Blood Institutes (NHLBI)/National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), Bethesda, MD, USA
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Eaton WA. Hemoglobin S polymerization and sickle cell disease: A retrospective on the occasion of the 70th anniversary of Pauling's Science paper. Am J Hematol 2020; 95:205-211. [PMID: 31763707 PMCID: PMC7003899 DOI: 10.1002/ajh.25687] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 11/05/2019] [Indexed: 12/12/2022]
Abstract
70 years ago, Linus Pauling, the legendary genius of 20th century chemistry, published his famous work on the molecular cause of sickle cell disease, a paper that gave birth to what is now called molecular medicine. In this paper, Pauling left important questions unanswered that have motivated an enormous amount of scientific and clinical research since then. This retrospective discusses the basic science studies that have answered those questions directly related to the kinetics and thermodynamics of hemoglobin S polymerization.
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Affiliation(s)
- William A. Eaton
- Laboratory of Chemical PhysicsNational Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health Bethesda Maryland
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