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Patel VJ, Joharapurkar A, Jain MR. The Perspective of Using Flow Cytometry for Unpuzzling Hypoxia-Inducible Factors Signalling. Drug Res (Stuttg) 2024; 74:113-122. [PMID: 38350634 DOI: 10.1055/a-2248-9180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2024]
Abstract
Hypoxia-inducible factors (HIFs) are transcription factors that are responsible for adapting to the changes in oxygen levels in the cellular environment. HIF activity determines the expression of cellular proteins that control the development and physiology of the cells and pathophysiology of a disease. Understanding the role of specific HIF (HIF-1-3) in cellular function is essential for development of the HIF-targeted therapies. In this review, we have discussed the use of flow cytometry in analysing HIF function in cells. Proper understanding of HIF-signalling will help to design pharmacological interventions HIF-mediated therapy. We have discussed the role of HIF-signalling in various diseases such as cancer, renal and liver diseases, ulcerative colitis, arthritis, diabetes and diabetic complications, psoriasis, and wound healing. We have also discussed protocols that help to decipher the role of HIFs in these diseases that would eventually help to design promising therapies.
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Affiliation(s)
- Vishal J Patel
- Department of Pharmacology and Toxicology, Zydus Research Centre, Zydus Lifesciences Limited, Moraiya, Ahmedabad, India
| | - Amit Joharapurkar
- Department of Pharmacology and Toxicology, Zydus Research Centre, Zydus Lifesciences Limited, Moraiya, Ahmedabad, India
| | - Mukul R Jain
- Department of Pharmacology and Toxicology, Zydus Research Centre, Zydus Lifesciences Limited, Moraiya, Ahmedabad, India
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2
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Rivera A, Vega C, Ramos-Rivera A, Maldonado ER, Prado GN, Karnes HE, Fesko YA, Snyder LM, Alper SL, Romero JR. Blockade of the mineralocorticoid receptor improves markers of human endothelial cell dysfunction and hematological indices in a mouse model of sickle cell disease. FASEB J 2023; 37:e23092. [PMID: 37482902 PMCID: PMC10372847 DOI: 10.1096/fj.202300671r] [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: 04/08/2023] [Revised: 06/24/2023] [Accepted: 07/03/2023] [Indexed: 07/25/2023]
Abstract
Increased endothelin-1 (ET-1) levels in patients with sickle cell disease (SCD) and transgenic mouse models of SCD contribute to disordered hematological, vascular, and inflammatory responses. Mineralocorticoid receptor (MR) activation by aldosterone, a critical component of the Renin-Angiotensin-Aldosterone-System, modulates inflammation and vascular reactivity, partly through increased ET-1 expression. However, the role of MR in SCD remains unclear. We hypothesized that MR blockade in transgenic SCD mice would reduce ET-1 levels, improve hematological parameters, and reduce inflammation. Berkeley SCD (BERK) mice, a model of severe SCD, were randomized to either sickle standard chow or chow containing the MR antagonist (MRA), eplerenone (156 mg/Kg), for 14 days. We found that MRA treatment reduced ET-1 plasma levels (p = .04), improved red cell density gradient profile (D50 ; p < .002), and increased mean corpuscular volume in both erythrocytes (p < .02) and reticulocytes (p < .024). MRA treatment also reduced the activity of the erythroid intermediate-conductance Ca2+ -activated K+ channel - KCa 3.1 (Gardos channel, KCNN4), reduced cardiac levels of mRNAs encoding ET-1, Tumor Necrosis Factor Receptor-1, and protein disulfide isomerase (PDI) (p < .01), and decreased plasma PDI and myeloperoxidase activity. Aldosterone (10-8 M for 24 h in vitro) also increased PDI mRNA levels (p < .01) and activity (p < .003) in EA.hy926 human endothelial cells, in a manner blocked by pre-incubation with the MRA canrenoic acid (1 μM; p < .001). Our results suggest a novel role for MR activation in SCD that may exacerbate SCD pathophysiology and clinical complications.
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Affiliation(s)
- Alicia Rivera
- Division of Nephrology, Vascular Biology Research Center, Department of Medicine, Beth Israel Deaconess Medical Center, and Harvard Medical School, Boston, Massachusetts, USA
- Departments of Laboratory Medicine and Pathology, Boston Children’s Hospital, Harvard Medical School, Boston, MA
| | - Christopher Vega
- Division of Endocrinology, Diabetes and Hypertension, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA
| | - Arelys Ramos-Rivera
- Division of Endocrinology, Diabetes and Hypertension, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA
| | - Enrique R. Maldonado
- Division of Endocrinology, Diabetes and Hypertension, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA
| | - Gregory N. Prado
- Departments of Laboratory Medicine and Pathology, Boston Children’s Hospital, Harvard Medical School, Boston, MA
- Division of Endocrinology, Diabetes and Hypertension, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA
| | | | | | | | - Seth L. Alper
- Division of Nephrology, Vascular Biology Research Center, Department of Medicine, Beth Israel Deaconess Medical Center, and Harvard Medical School, Boston, Massachusetts, USA
| | - Jose R. Romero
- Division of Endocrinology, Diabetes and Hypertension, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA
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3
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Xi C, Pang J, Zhi W, Chang CSS, Siddaramappa U, Shi H, Horuzsko A, Pace BS, Zhu X. Nrf2 sensitizes ferroptosis through l-2-hydroxyglutarate-mediated chromatin modifications in sickle cell disease. Blood 2023; 142:382-396. [PMID: 37267508 PMCID: PMC10485372 DOI: 10.1182/blood.2022018159] [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: 08/19/2022] [Revised: 04/07/2023] [Accepted: 04/10/2023] [Indexed: 06/04/2023] Open
Abstract
Sickle cell disease (SCD) is a chronic hemolytic and systemic hypoxia condition with constant oxidative stress and significant metabolic alterations. However, little is known about the correlation between metabolic alterations and the pathophysiological symptoms. Here, we report that Nrf2, a master regulator of cellular antioxidant responses, regulates the production of the metabolite l-2-hydroxyglutarate (L2HG) to mediate epigenetic histone hypermethylation for gene expression involved in metabolic, oxidative, and ferroptotic stress responses in SCD. Mechanistically, Nrf2 was found to regulate the expression of L2HG dehydrogenase (L2hgdh) to mediate L2HG production under hypoxia. Gene expression profile analysis indicated that reactive oxygen species (ROS) and ferroptosis responses were the most significantly affected signaling pathways after Nrf2 ablation in SCD. Nrf2 silencing and L2HG supplementation sensitize human sickle erythroid cells to ROS and ferroptosis stress. The absence of Nrf2 and accumulation of L2HG significantly affect histone methylation for chromatin structure modification and reduce the assembly of transcription complexes on downstream target genes to regulate ROS and ferroptosis responses. Furthermore, pharmacological activation of Nrf2 was found to have protective effects against ROS and ferroptosis stress in SCD mice. Our data suggest a novel mechanism by which Nrf2 regulates L2HG levels to mediate SCD severity through ROS and ferroptosis stress responses, suggesting that targeting Nrf2 is a viable therapeutic strategy for ameliorating SCD symptoms.
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Affiliation(s)
- Caixia Xi
- Georgia Cancer Center, Augusta University, Augusta, GA
| | - Junfeng Pang
- Georgia Cancer Center, Augusta University, Augusta, GA
| | - Wenbo Zhi
- Center for Biotechnology and Genomic Medicine, Consolidated Proteomics and Mass Spectrometry Core Lab, Augusta University, Augusta, GA
| | - Chang-Sheng S. Chang
- Bioinformatics Shared Resource and Integrated Genomics, Georgia Cancer Center, Augusta University, Augusta, GA
| | - Umapathy Siddaramappa
- Division of Hematology/Oncology, Department of Pediatrics, Augusta University, Augusta, GA
| | - Huidong Shi
- Georgia Cancer Center, Augusta University, Augusta, GA
| | | | - Betty S. Pace
- Division of Hematology/Oncology, Department of Pediatrics, Augusta University, Augusta, GA
| | - Xingguo Zhu
- Georgia Cancer Center, Augusta University, Augusta, GA
- Division of Hematology/Oncology, Department of Pediatrics, Augusta University, Augusta, GA
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4
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Pedrosa AM, Lemes RPG. Gene expression of HIF-1α and VEGF in response to hypoxia in sickle cell anaemia: Influence of hydroxycarbamide. Br J Haematol 2020; 190:e39-e42. [PMID: 32352161 DOI: 10.1111/bjh.16693] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 04/02/2020] [Accepted: 04/03/2020] [Indexed: 01/09/2023]
Abstract
Hypoxia and hemoglobin S polymerization are two triggers responsible for initiating erythrocyte sickling and the consequent clinical sickle cell anemia (SCA) events. The objective of this study was to investigate the expression of hypoxia-responsive genes in SCA, testing for correlation with the clinical-laboratorial characteristics of the patient and hydroxyurea therapy. Our results showed, for the first time, a significantly increased expression of HIF-1α and VEGF genes in patients with SCA and an inverse dose-response relationship with hydroxyurea therapy. These results suggest that hypoxic stress may be involved in both the severity of SCA and its response to treatment.
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Affiliation(s)
- Alano M Pedrosa
- Research Laboratory on Hemoglobinopathies and Hematological Genetic Diseases, Department of Clinical and Toxicological Analysis, Faculty of Pharmacy, Federal University of Ceará, Fortaleza-CE, Brazil
| | - Romélia P G Lemes
- Research Laboratory on Hemoglobinopathies and Hematological Genetic Diseases, Department of Clinical and Toxicological Analysis, Faculty of Pharmacy, Federal University of Ceará, Fortaleza-CE, Brazil
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5
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Khan N, Chen X, Geiger JD. Role of Divalent Cations in HIV-1 Replication and Pathogenicity. Viruses 2020; 12:E471. [PMID: 32326317 PMCID: PMC7232465 DOI: 10.3390/v12040471] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/09/2020] [Accepted: 04/18/2020] [Indexed: 12/22/2022] Open
Abstract
Divalent cations are essential for life and are fundamentally important coordinators of cellular metabolism, cell growth, host-pathogen interactions, and cell death. Specifically, for human immunodeficiency virus type-1 (HIV-1), divalent cations are required for interactions between viral and host factors that govern HIV-1 replication and pathogenicity. Homeostatic regulation of divalent cations' levels and actions appear to change as HIV-1 infection progresses and as changes occur between HIV-1 and the host. In people living with HIV-1, dietary supplementation with divalent cations may increase HIV-1 replication, whereas cation chelation may suppress HIV-1 replication and decrease disease progression. Here, we review literature on the roles of zinc (Zn2+), iron (Fe2+), manganese (Mn2+), magnesium (Mg2+), selenium (Se2+), and copper (Cu2+) in HIV-1 replication and pathogenicity, as well as evidence that divalent cation levels and actions may be targeted therapeutically in people living with HIV-1.
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Affiliation(s)
| | | | - Jonathan D. Geiger
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58203, USA; (N.K.); (X.C.)
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6
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Faes C, Juban G, Aufradet E, Desgeorges T, Charrin E, Connes P, Mury P, Mattè A, De Franceschi L, Martin C, Pialoux V. Effects of hypoxia-reoxygenation stimuli on renal redox status and nuclear factor erythroid 2-related factor 2 pathway in sickle cell SAD mice. Exp Physiol 2019; 105:357-369. [PMID: 31805612 DOI: 10.1113/ep087969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 12/02/2019] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? What are the effects of repeated subclinical vaso-occlusions on nuclear factor erythroid 2 related factor 2 (Nrf2) and oxidative stress balance regulation in the kidney of transgenic SAD mice? What is the main finding and its importance? In response to hypoxia-reoxygenation, nuclear Nrf2 protein expression decreased in the kidney of SAD mice while haem oxygenase transcripts were increased. This suggest that in SAD mice, other transcription factors than Nrf2 could be involved in renal antioxidant gene regulation in response to hypoxia-reoxygenation. ABSTRACT Hypoxia-reoxygenation (H/R) stress is known to increase oxidative stress in transgenic sickle mice and can cause organ failure. Here we described the effects of H/R on nuclear factor erythroid 2-related factor 2 (Nrf2) as a putative regulator of redox status in the kidneys of SAD mice investigating Nrf2-regulated antioxidant enzymes. Transgenic SAD mice and healthy C57Bl/6J mice were exposed to 4 h of hypoxia followed by various times of reoxygenation at ambient air (2 or 6 h). Regardless of the conditions (i.e. normoxia or H/R), SAD mice expressed higher renal oxidative stress levels. Nuclear Nrf2 protein expression decreased after 2 h post-hypoxia only in the medulla region of the kidney and only in SAD mice. Simultaneously, haem oxygenase transcripts were affected by H/R stimulus with a significant enhancement after 2 h post-hypoxia. Similarly, hypoxia inducible factor-1α staining increased after 2 h post-hypoxia in SAD mice in both cortex and medulla areas. Our data confirm that the kidneys are organs that are particularly sensitive to H/R stimuli in sickle cell SAD mice. Also, these results suggest an effect of the duration of recovery period (short vs. long) and specific responses according to kidney areas, medulla vs. cortex, on Nrf2 expression in response to H/R stimuli in SAD mice.
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Affiliation(s)
- Camille Faes
- Interuniversity Laboratory of Human Movement Biology EA7424, Univ Lyon - University Claude Bernard Lyon 1, Villeurbanne, France.,Labex GR-Ex, Paris, France
| | - Gaëtan Juban
- Institut NeuroMyoGène CNRS UMR 5510, INSERM U1217, Univ Lyon - University Claude Bernard Lyon 1, Lyon, France
| | - Emeline Aufradet
- Interuniversity Laboratory of Human Movement Biology EA7424, Univ Lyon - University Claude Bernard Lyon 1, Villeurbanne, France
| | - Thibaut Desgeorges
- Institut NeuroMyoGène CNRS UMR 5510, INSERM U1217, Univ Lyon - University Claude Bernard Lyon 1, Lyon, France
| | - Emmanuelle Charrin
- Interuniversity Laboratory of Human Movement Biology EA7424, Univ Lyon - University Claude Bernard Lyon 1, Villeurbanne, France.,Labex GR-Ex, Paris, France
| | - Philippe Connes
- Interuniversity Laboratory of Human Movement Biology EA7424, Univ Lyon - University Claude Bernard Lyon 1, Villeurbanne, France.,Labex GR-Ex, Paris, France.,Institut Universitaire de France, Paris, France
| | - Pauline Mury
- Interuniversity Laboratory of Human Movement Biology EA7424, Univ Lyon - University Claude Bernard Lyon 1, Villeurbanne, France.,Labex GR-Ex, Paris, France
| | - Alessandro Mattè
- Department of Medicine, University of Verona and AOUI-Verona, Verona, Italy
| | | | - Cyril Martin
- Interuniversity Laboratory of Human Movement Biology EA7424, Univ Lyon - University Claude Bernard Lyon 1, Villeurbanne, France.,Labex GR-Ex, Paris, France
| | - Vincent Pialoux
- Interuniversity Laboratory of Human Movement Biology EA7424, Univ Lyon - University Claude Bernard Lyon 1, Villeurbanne, France.,Labex GR-Ex, Paris, France.,Institut Universitaire de France, Paris, France
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7
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Merlet AN, Chatel B, Hourdé C, Ravelojaona M, Bendahan D, Féasson L, Messonnier LA. How Sickle Cell Disease Impairs Skeletal Muscle Function: Implications in Daily Life. Med Sci Sports Exerc 2019; 51:4-11. [PMID: 30095751 DOI: 10.1249/mss.0000000000001757] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Sickle cell disease (SCD) is the most frequent life-threatening genetic hemoglobinopathy in the world and occurs due to the synthesis of abnormal hemoglobin S (HbS). hemoglobin S-containing red blood cells (RBC) are fragile, leading to hemolysis and anemia, and adhere to the endothelium, leading to hemorheological and hemodynamical disturbances. In its deoxygenated form, HbS may polymerize, leading to sickling of red blood cells and potentially to vasoocclusive crises. Recent findings observed that SCD patients demonstrate significant skeletal muscle remodeling and display reduced muscle functional capacities, contributing to exercise intolerance and poor quality of life. Although acute high-intensity exercise is not recommended for SCD patients because it may increase the risk of sickling, regular moderate-intensity physical activity could have beneficial effects on skeletal muscle and more generally on the well-being of SCD patients. This article reviews the literature regarding the impact of the disease on muscular tissue characteristics and function, as well as the corresponding implications for SCD patients' quality of life.
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Affiliation(s)
- Angèle N Merlet
- Inter-university Laboratory of Human Movement Sciences, University of Lyon, UJM Saint-Etienne, Saint-Etienne, FRANCE
| | - Benjamin Chatel
- Inter-university Laboratory of Human Movement Sciences, University of Savoie Mont Blanc, Chambéry, FRANCE.,Aix-Marseille University, Marseille, FRANCE
| | - Christophe Hourdé
- Inter-university Laboratory of Human Movement Sciences, University of Savoie Mont Blanc, Chambéry, FRANCE
| | - Marion Ravelojaona
- Inter-university Laboratory of Human Movement Sciences, University of Lyon, UJM Saint-Etienne, Saint-Etienne, FRANCE.,Myology Unit, Department of Clinical and Exercise Physiology, University Hospital of Saint-Etienne, Saint-Etienne, FRANCE
| | | | - Léonard Féasson
- Inter-university Laboratory of Human Movement Sciences, University of Lyon, UJM Saint-Etienne, Saint-Etienne, FRANCE.,Inter-university Laboratory of Human Movement Sciences, University of Savoie Mont Blanc, Chambéry, FRANCE.,Aix-Marseille University, Marseille, FRANCE.,Myology Unit, Department of Clinical and Exercise Physiology, University Hospital of Saint-Etienne, Saint-Etienne, FRANCE
| | - Laurent A Messonnier
- Inter-university Laboratory of Human Movement Sciences, University of Savoie Mont Blanc, Chambéry, FRANCE
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8
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Hong M, Shi H, Wang N, Tan HY, Wang Q, Feng Y. Dual Effects of Chinese Herbal Medicines on Angiogenesis in Cancer and Ischemic Stroke Treatments: Role of HIF-1 Network. Front Pharmacol 2019; 10:696. [PMID: 31297056 PMCID: PMC6606950 DOI: 10.3389/fphar.2019.00696] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 05/29/2019] [Indexed: 12/21/2022] Open
Abstract
Hypoxia-inducible factor-1 (HIF-1)–induced angiogenesis has been involved in numerous pathological conditions, and it may be harmful or beneficial depending on the types of diseases. Exploration on angiogenesis has sparked hopes in providing novel therapeutic approaches on multiple diseases with high mortality rates, such as cancer and ischemic stroke. The HIF-1 pathway is considered to be a major regulator of angiogenesis. HIF-1 seems to be involved in the vascular formation process by synergistic correlations with other proangiogenic factors in cancer and cerebrovascular disease. The regulation of HIF-1–dependent angiogenesis is related to the modulation of HIF-1 bioactivity by regulating HIF-1α transcription or protein translation, HIF-1α DNA binding, HIF-1α and HIF-1α dimerization, and HIF-1 degradation. Traditional Chinese herbal medicines have a long history of clinical use in both cancer and stroke treatments in Asia. Growing evidence has demonstrated potential proangiogenic benefits of Chinese herbal medicines in ischemic stroke, whereas tumor angiogenesis could be inhibited by the active components in Chinese herbal medicines. The objective of this review is to provide comprehensive insight on the effects of Chinese herbal medicines on angiogenesis by regulating HIF-1 pathways in both cancer and ischemic stroke.
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Affiliation(s)
- Ming Hong
- Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Honglian Shi
- Department of Pharmacology and Toxicology, University of Kansas, Lawrence, KS, United States
| | - Ning Wang
- School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Hor-Yue Tan
- School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Qi Wang
- Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Yibin Feng
- School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
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9
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Resolution of sickle cell disease-associated inflammation and tissue damage with 17 R-resolvin D1. Blood 2018; 133:252-265. [PMID: 30404812 DOI: 10.1182/blood-2018-07-865378] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 10/23/2018] [Indexed: 02/07/2023] Open
Abstract
Resolvins (Rvs), endogenous lipid mediators, play a key role in the resolution of inflammation. Sickle cell disease (SCD), a genetic disorder of hemoglobin, is characterized by inflammatory and vaso-occlusive pathologies. We document altered proresolving events following hypoxia/reperfusion in humanized SCD mice. We demonstrate novel protective actions of 17R-resolvin D1 (17R-RvD1; 7S, 8R, 17R-trihydroxy-4Z, 9E, 11E, 13Z, 15E, 19Z-docosahexaenoic acid) in reducing ex vivo human SCD blood leukocyte recruitment by microvascular endothelial cells and in vivo neutrophil adhesion and transmigration. In SCD mice exposed to hypoxia/reoxygenation, oral administration of 17R -RvD1 reduces systemic/local inflammation and vascular dysfunction in lung and kidney. The mechanism of action of 17R-RvD1 involves (1) enhancement of SCD erythrocytes and polymorphonuclear leukocyte efferocytosis, (2) blunting of NF-κB activation, and (3) a reduction in inflammatory cytokines, vascular activation markers, and E-selectin expression. Thus, 17R-RvD1 might represent a new therapeutic strategy for the inflammatory vasculopathy of SCD.
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10
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Meeks D, Navaratnarajah A, Drasar E, Jaffer O, Wilkins CJ, Thein SL, Sharpe CC. Increased prevalence of renal cysts in patients with sickle cell disease. BMC Nephrol 2017; 18:298. [PMID: 28934953 PMCID: PMC5609069 DOI: 10.1186/s12882-017-0714-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 09/07/2017] [Indexed: 12/27/2022] Open
Abstract
Background Early detection and interventions have enabled patients with sickle cell disease (SCD) to live well into adulthood. Consequently, the chronicity of SCD allows for the insidious manifestation of multisystem complications, including renal damage. Cystic renal lesions are commonly incidentally discovered on ultrasound and computerised tomography (CT) imaging of the abdomen. Most are benign simple cysts, however, difficulties may be encountered if infection, rupture, haemorrhage or cancerous changes develop. We aimed to determine whether patients with SCD have a higher prevalence of simple renal cysts compared to non-SCD individuals. Methods Data for a group of 223 patients with SCD who had undergone an ultrasound and/or CT imaging of the abdomen were extracted for comparison with 180 control patients (haemoglobin genotype unknown), matched for age and ethnicity. Scans were evaluated for 198 SCD patients and 180 controls. Results Renal cysts were found in 58% of the SCD group and 20% of the controls (OR 5.4 (CI 2.6–11.0), RR 2.8 (CI 1.9–4.2)). Bilateral renal cysts were found in 28% of the SCD participants in comparison with 5% of the control group. In those who had one or more cysts identified, the average number of cysts was 3.76 for the SCD group and 1.94 for the controls. Men with SCD were more likely to develop cysts than women (66% vs 53%), as were men without SCD (22% vs 17%). Conclusions Simple renal cysts occur more frequently, are more abundant and develop at a younger age in patients with SCD than ethnically-matched controls. Further study of the mechanism underlying cyst formation may shed light on both sickle cell nephropathy and other cystic renal diseases.
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Affiliation(s)
- Daveena Meeks
- King's College London, Faculty of Life Sciences & Medicine, London, UK.,Royal Sussex County Hospital, Brighton, UK
| | | | - Emma Drasar
- Red Cell Centre, Whittington Hospital, London, UK
| | - Ounali Jaffer
- Department of Radiology, The Royal London Hospital, Barts Health NHS Trust, London, UK
| | - C Jason Wilkins
- Department of Radiology, King's College Hospital NHS Foundation Trust, London, UK
| | - Swee Lay Thein
- King's College London, Faculty of Life Sciences & Medicine, Molecular Haematology, London, UK.,National Heart, Lung and Blood Institute, The National Institutes of Health, Sickle Cell Branch, Bethesda, USA
| | - Claire C Sharpe
- Department of Renal Sciences, Division of Transplantation Immunology and Mucosal Biology, Faculty of Life Sciences and Medicine, King's College London, London, SE5 9RJ, UK.
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11
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Increased iron export by ferroportin induces restriction of HIV-1 infection in sickle cell disease. Blood Adv 2016; 1:170-183. [PMID: 28203649 DOI: 10.1182/bloodadvances.2016000745] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The low incidence of HIV-1 infection in patients with sickle cell disease (SCD) and inhibition of HIV-1 replication in vitro under the conditions of low intracellular iron or heme treatment suggests a potential restriction of HIV-1 infection in SCD. We investigated HIV-1 ex vivo infection of SCD peripheral blood mononuclear cells (PBMCs) and found that HIV-1 replication was inhibited at the level of reverse transcription (RT) and transcription. We observed increased expression of heme and iron-regulated genes, previously shown to inhibit HIV-1, including ferroportin, IKBα, HO-1, p21, and SAM domain and HD domain-containing protein 1 (SAMHD1). HIV-1 inhibition was less pronounced in hepcidin-treated SCD PBMCs and more pronounced in the iron or iron chelators treated, suggesting a key role of iron metabolism. In SCD PBMCs, labile iron levels were reduced and protein levels of ferroportin, HIF-1α, IKBα, and HO-1 were increased. Hemin treatment induced ferroportin expression and inhibited HIV-1 in THP-1 cells, mimicking the HIV-1 inhibition in SCD PBMCs, especially as hepcidin similarly prevented HIV-1 inhibition. In THP-1 cells with knocked down ferroportin, IKBα, or HO-1 genes but not HIF-1α or p21, HIV-1 was not inhibited by hemin. Activity of SAMHD1-regulatory CDK2 was decreased, and SAMHD1 phosphorylation was reduced in SCD PBMCs and hemin-treated THP-1 cells, suggesting SAMHD1-mediated HIV-1 restriction in SCD. Our findings point to ferroportin as a trigger of HIV-1 restriction in SCD settings, linking reduced intracellular iron levels to the inhibition of CDK2 activity, reduction of SAMHD1 phosphorylation, increased IKBα expression, and inhibition of HIV-1 RT and transcription.
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12
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Chen D, Jin Z, Zhang J, Jiang L, Chen K, He X, Song Y, Ke J, Wang Y. HO-1 Protects against Hypoxia/Reoxygenation-Induced Mitochondrial Dysfunction in H9c2 Cardiomyocytes. PLoS One 2016; 11:e0153587. [PMID: 27138700 PMCID: PMC4854406 DOI: 10.1371/journal.pone.0153587] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 03/31/2016] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Mitochondrial dysfunction would ultimately lead to myocardial cell apoptosis and death during ischemia-reperfusion injuries. Autophagy could ameliorate mitochondrial dysfunction by autophagosome forming, which is a catabolic process to preserve the mitochondrial's structural and functional integrity. HO-1 induction and expression are important protective mechanisms. This study in order to investigate the role of HO-1 during mitochondrial damage and its mechanism. METHODS AND RESULTS The H9c2 cardiomyocyte cell line were incubated by hypoxic and then reoxygenated for the indicated time (2, 6, 12, 18, and 24 h). Cell viability was tested with CCK-8 kit. The expression of endogenous HO-1(RT-PCR and Western blot) increased with the duration of reoxygenation and reached maximum levels after 2 hours of H/R; thereafter, the expression gradually decreased to a stable level. Mitochondrial dysfunction (Flow cytometry quantified the ROS generation and JC-1 staining) and autophagy (The Confocal microscopy measured the autophagy. RFP-GFP-LC3 double-labeled adenovirus was used for testing.) were induced after 6 hours of H/R. Then, genetic engineering technology was employed to construct an Lv-HO1-H9c2 cell line. When HO-1 was overexpressed, the LC3II levels were significantly increased after reoxygenation, p62 protein expression was significantly decreased, the level of autophagy was unchanged, the mitochondrial membrane potential was significantly increased, and the mitochondrial ROS level was significantly decreased. Furthermore, when the HO-1 inhibitor ZnPP was applied the level of autophagy after reoxygenation was significantly inhibited, and no significant improvement in mitochondrial dysfunction was observed. CONCLUSIONS During myocardial hypoxia-reoxygenation injury, HO-1 overexpression induces autophagy to protect the stability of the mitochondrial membrane and reduce the amount of mitochondrial oxidation products, thereby exerting a protective effect.
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Affiliation(s)
- Dongling Chen
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Zhe Jin
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Jingjing Zhang
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Linlin Jiang
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Kai Chen
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Xianghu He
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Yinwei Song
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jianjuan Ke
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Yanlin Wang
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, Wuhan, China
- * E-mail:
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13
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Ghosh S, Ihunnah CA, Hazra R, Walker AL, Hansen JM, Archer DR, Owusu-Ansah AT, Ofori-Acquah SF. Nonhematopoietic Nrf2 dominantly impedes adult progression of sickle cell anemia in mice. JCI Insight 2016; 1:81090. [PMID: 27158670 DOI: 10.1172/jci.insight.81090] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The prevention of organ damage and early death in young adults is a major clinical concern in sickle cell disease (SCD). However, mechanisms that control adult progression of SCD during the transition from adolescence are poorly defined with no cognate prophylaxis. Here, we demonstrate in a longitudinal cohort of homozygous SCD (SS) mice a link between intravascular hemolysis, vascular inflammation, lung injury, and early death. Prophylactic Nrf2 activation in young SS mice stabilized intravascular hemolysis, reversed vascular inflammation, and attenuated lung edema in adulthood. Enhanced Nrf2 activation in endothelial cells in vitro concurred with the dramatic effect on vascular inflammation in the mice. BM chimeric SS mice lacking Nrf2 expression in nonhematopoietic tissues were created to dissect the role of nonerythroid Nrf2 in SCD progression. The SS chimeras developed severe intravascular hemolysis despite having erythroid Nrf2. In addition, they developed premature vascular inflammation and pulmonary edema and died younger than donor littermates with intact nonhematopoietic Nrf2. Our results reveal a dominant protective role for nonhematopoietic Nrf2 against tissue damage in both erythroid and nonerythroid tissues in SCD. Furthermore, we show that prophylactic augmentation of Nrf2-coordinated cytoprotection effectively impedes onset of the severe adult phenotype of SCD in mice.
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Affiliation(s)
- Samit Ghosh
- Division of Hematology/Oncology, and.,Center for Translational and International Hematology, Vascular Medicine Institute, Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Chibueze A Ihunnah
- Center for Translational and International Hematology, Vascular Medicine Institute, Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Rimi Hazra
- Center for Translational and International Hematology, Vascular Medicine Institute, Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Aisha L Walker
- Center for Translational and International Hematology, Vascular Medicine Institute, Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Jason M Hansen
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, Utah, USA
| | - David R Archer
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Amma T Owusu-Ansah
- Division of Hematology/Oncology, and.,Center for Translational and International Hematology, Vascular Medicine Institute, Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Solomon F Ofori-Acquah
- Division of Hematology/Oncology, and.,Center for Translational and International Hematology, Vascular Medicine Institute, Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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14
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Tan F, Ghosh S, Mosunjac M, Manci E, Ofori-Acquah SF. Original Research: Diametric effects of hypoxia on pathophysiology of sickle cell disease in a murine model. Exp Biol Med (Maywood) 2016; 241:766-71. [PMID: 27026725 DOI: 10.1177/1535370216642046] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Hypoxia causes erythrocyte sickling in vitro; however, its role in the pathophysiology of sickle cell disease is poorly understood. We report that hypoxia rapidly decreased oxygen saturation in transgenic sickle cell disease mice, but this effect was immediately buffered by a robust ventilatory response. The initial hypoxemia improved steadily throughout the duration of hypoxia without any detectable acute pulmonary adverse effect. Furthermore, the mice suffered acute anemia that ironically was associated with lowering of both plasma hemoglobin and heme. These results were corroborated by increased plasma haptoglobin and hemopexin levels. Markers of ischemic tissue injury increased spatiotemporally following repeated hypoxia exposures. This variation was supported by organ-specific induction of hypoxia-responsive genes. Our results show that hypoxia exerts diametric effects on sickle cell disease by promoting ischemic injury while enhancing the expression of hemolysis scavenger molecules. This phenomenon may help to understand the disparate clinical syndromes associated with hemolysis and vaso-occlusion in sickle cell disease.
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Affiliation(s)
- Fang Tan
- Aflac Cancer Center and Blood Disorders Service, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Samit Ghosh
- Depatment of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Mario Mosunjac
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Elizabeth Manci
- Children's and Women's Hospital, University of South Alabama, Mobile, AL 36604, USA
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15
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Lopes FCM, Traina F, Almeida CB, Leonardo FC, Franco-Penteado CF, Garrido VT, Colella MP, Soares R, Olalla-Saad ST, Costa FF, Conran N. Key endothelial cell angiogenic mechanisms are stimulated by the circulating milieu in sickle cell disease and attenuated by hydroxyurea. Haematologica 2015; 100:730-9. [PMID: 25769545 DOI: 10.3324/haematol.2014.119727] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 03/05/2015] [Indexed: 01/05/2023] Open
Abstract
As hypoxia-induced inflammatory angiogenesis may contribute to the manifestations of sickle cell disease, we compared the angiogenic molecular profiles of plasma from sickle cell disease individuals and correlated these with in vitro endothelial cell-mediated angiogenesis-stimulating activity and in vivo neovascularization. Bioplex demonstrated that plasma from patients with steady-state sickle cell anemia contained elevated concentrations of pro-angiogenic factors (angiopoietin-1, basic fibroblast growth factor, vascular endothelial growth factor, vascular endothelial growth factor-D and placental growth factor) and displayed potent pro-angiogenic activity, significantly increasing endothelial cell proliferation, migration and capillary-like structure formation. In vivo neovascularization of Matrigel plugs was significantly greater in sickle cell disease mice than in non-sickle cell disease mice, consistent with an up-regulation of angiogenesis in the disease. In plasma from patients with hemoglobin SC disease without proliferative retinopathy, anti-angiogenic endostatin and thrombospondin-2 were significantly elevated. In contrast, plasma from hemoglobin SC individuals with proliferative retinopathy had a pro-angiogenic profile and more significant effects on endothelial cell proliferation and capillary formation than plasma from patients without retinopathy. Hydroxyurea therapy was associated with significant reductions in plasma angiogenic factors and inhibition of endothelial cell-mediated angiogenic mechanisms and neovascularization. Thus, individuals with sickle cell anemia or hemoglobin SC disease with retinopathy present a highly angiogenic circulating milieu, capable of stimulating key endothelial cell-mediated angiogenic mechanisms. Combination anti-angiogenic therapy to prevent the progression of unregulated neovascularization and associated manifestations in sickle cell disease, such as pulmonary hypertension, may be indicated; furthermore, the benefits and drawbacks of the potent anti-angiogenic effects of hydroxyurea should be clarified.
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Affiliation(s)
- Flavia C M Lopes
- INCT de Sangue, Hematology Center, School of Medical Science, University of Campinas - UNICAMP, São Paulo, Brazil
| | - Fabiola Traina
- INCT de Sangue, Hematology Center, School of Medical Science, University of Campinas - UNICAMP, São Paulo, Brazil Department of Internal Medicine, University of São Paulo at Riberão Preto Medical School, Riberão Preto, Brazil
| | - Camila B Almeida
- INCT de Sangue, Hematology Center, School of Medical Science, University of Campinas - UNICAMP, São Paulo, Brazil
| | - Flavia C Leonardo
- INCT de Sangue, Hematology Center, School of Medical Science, University of Campinas - UNICAMP, São Paulo, Brazil
| | - Carla F Franco-Penteado
- INCT de Sangue, Hematology Center, School of Medical Science, University of Campinas - UNICAMP, São Paulo, Brazil
| | - Vanessa T Garrido
- INCT de Sangue, Hematology Center, School of Medical Science, University of Campinas - UNICAMP, São Paulo, Brazil
| | - Marina P Colella
- INCT de Sangue, Hematology Center, School of Medical Science, University of Campinas - UNICAMP, São Paulo, Brazil
| | - Raquel Soares
- Department of Biochemistry (I3S), Faculty of Medicine, University of Porto, Portugal
| | - Sara T Olalla-Saad
- INCT de Sangue, Hematology Center, School of Medical Science, University of Campinas - UNICAMP, São Paulo, Brazil
| | - Fernando F Costa
- INCT de Sangue, Hematology Center, School of Medical Science, University of Campinas - UNICAMP, São Paulo, Brazil
| | - Nicola Conran
- INCT de Sangue, Hematology Center, School of Medical Science, University of Campinas - UNICAMP, São Paulo, Brazil
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16
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Potoka KP, Gladwin MT. Vasculopathy and pulmonary hypertension in sickle cell disease. Am J Physiol Lung Cell Mol Physiol 2014; 308:L314-24. [PMID: 25398989 DOI: 10.1152/ajplung.00252.2014] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Sickle cell disease (SCD) is an autosomal recessive disorder in the gene encoding the β-chain of hemoglobin. Deoxygenation causes the mutant hemoglobin S to polymerize, resulting in rigid, adherent red blood cells that are entrapped in the microcirculation and hemolyze. Cardinal features include severe painful crises and episodic acute lung injury, called acute chest syndrome. This population, with age, develops chronic organ injury, such as chronic kidney disease and pulmonary hypertension. A major risk factor for developing chronic organ injury is hemolytic anemia, which releases red blood cell contents into the circulation. Cell free plasma hemoglobin, heme, and arginase 1 disrupt endothelial function, drive oxidative and inflammatory stress, and have recently been referred to as erythrocyte damage-associated molecular pattern molecules (eDAMPs). Studies suggest that in addition to effects of cell free plasma hemoglobin on scavenging nitric oxide (NO) and generating reactive oxygen species (ROS), heme released from plasma hemoglobin can bind to the toll-like receptor 4 to activate the innate immune system. Persistent intravascular hemolysis over decades leads to chronic vasculopathy, with ∼10% of patients developing pulmonary hypertension. Progressive obstruction of small pulmonary arterioles, increase in pulmonary vascular resistance, decreased cardiac output, and eventual right heart failure causes death in many patients with this complication. This review provides an overview of the pathobiology of hemolysis-mediated endothelial dysfunction and eDAMPs and a summary of our present understanding of diagnosis and management of pulmonary hypertension in sickle cell disease, including a review of recent American Thoracic Society (ATS) consensus guidelines for risk stratification and management.
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Affiliation(s)
- Karin P Potoka
- Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania; Division of Newborn Medicine, Department of Pediatrics, University of Pittsburgh, Pittsburgh, Pennsylvania; and
| | - Mark T Gladwin
- Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania; Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
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17
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Platelet bioenergetic screen in sickle cell patients reveals mitochondrial complex V inhibition, which contributes to platelet activation. Blood 2014; 123:2864-72. [PMID: 24677541 DOI: 10.1182/blood-2013-09-529420] [Citation(s) in RCA: 113] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Bioenergetic dysfunction, although central to the pathogenesis of numerous diseases, remains uncharacterized in many patient populations because of the invasiveness of obtaining tissue for mitochondrial studies. Although platelets are an accessible source of mitochondria, the role of bioenergetics in regulating platelet function remains unclear. Herein, we validate extracellular flux analysis in human platelets and use this technique to screen for mitochondrial dysfunction in sickle cell disease (SCD) patients, a population with aberrant platelet activation of an unknown mechanism and in which mitochondrial function has never been assessed. We identify a bioenergetic alteration in SCD patients characterized by deficient complex V activity, leading to decreased mitochondrial respiration, membrane hyperpolarization, and augmented oxidant production compared with healthy subjects. This dysfunction correlates with platelet activation and hemolysis in vivo and can be recapitulated in vitro by exposing healthy platelets to hemoglobin or a complex V inhibitor. Further, reproduction of this dysfunction in vitro activates healthy platelets, an effect prevented by attenuation of mitochondrial hyperpolarization or by scavenging mitochondrial oxidants. These data identify bioenergetic dysfunction in SCD patients for the first time and establish mitochondrial hyperpolarization and oxidant generation as potential pathogenic mechanism in SCD as well as a modulator of healthy platelet function.
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18
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Ghosh S, Adisa OA, Chappa P, Tan F, Jackson KA, Archer DR, Ofori-Acquah SF. Extracellular hemin crisis triggers acute chest syndrome in sickle mice. J Clin Invest 2014; 123:4809-20. [PMID: 24084741 DOI: 10.1172/jci64578] [Citation(s) in RCA: 203] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Accepted: 08/01/2013] [Indexed: 01/29/2023] Open
Abstract
The prevention and treatment of acute chest syndrome (ACS) is a major clinical concern in sickle cell disease (SCD). However, the mechanism underlying the pathogenesis of ACS remains elusive. We tested the hypothesis that the hemolysis byproduct hemin elicits events that induce ACS. Infusion of a low dose of hemin caused acute intravascular hemolysis and autoamplification of extracellular hemin in transgenic sickle mice, but not in sickle-trait littermates. The sickle mice developed multiple symptoms typical of ACS and succumbed rapidly. Pharmacologic inhibition of TLR4 and hemopexin replacement therapy prior to hemin infusion protected sickle mice from developing ACS. Replication of the ACS-like phenotype in nonsickle mice revealed that the mechanism of lung injury due to extracellular hemin is independent of SCD. Using genetic and bone marrow chimeric tools, we confirmed that TLR4 expressed in nonhematopoietic vascular tissues mediated this lethal type of acute lung injury. Respiratory failure was averted after the onset of ACS-like symptoms in sickle mice by treating them with recombinant hemopexin. Our results reveal a mechanism that helps to explain the pathogenesis of ACS, and we provide proof of principle for therapeutic strategies to prevent and treat this condition in mice.
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MESH Headings
- Acute Chest Syndrome/blood
- Acute Chest Syndrome/etiology
- Acute Chest Syndrome/prevention & control
- Anemia, Sickle Cell/blood
- Anemia, Sickle Cell/complications
- Anemia, Sickle Cell/genetics
- Animals
- Disease Models, Animal
- Extracellular Space/metabolism
- Hemin/metabolism
- Hemoglobin, Sickle/genetics
- Hemoglobin, Sickle/metabolism
- Hemolysis
- Hemopexin/therapeutic use
- Humans
- Mice
- Mice, Inbred C3H
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Mutant Strains
- Mice, Transgenic
- Recombinant Proteins/therapeutic use
- Sickle Cell Trait/blood
- Sickle Cell Trait/complications
- Sickle Cell Trait/genetics
- Sulfonamides/pharmacology
- Toll-Like Receptor 4/deficiency
- Toll-Like Receptor 4/genetics
- Toll-Like Receptor 4/metabolism
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19
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Green NS, Barral S. Emerging science of hydroxyurea therapy for pediatric sickle cell disease. Pediatr Res 2014; 75:196-204. [PMID: 24252885 PMCID: PMC3917141 DOI: 10.1038/pr.2013.227] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2013] [Accepted: 10/25/2013] [Indexed: 12/16/2022]
Abstract
Hydroxyurea (HU) is the sole approved pharmacological therapy for sickle cell disease (SCD). Higher levels of fetal hemoglobin (HbF) diminish deoxygenated sickle globin polymerization in vitro and clinically reduce the incidence of disease morbidities. Clinical and laboratory effects of HU largely result from induction of HbF expression, though to a highly variable extent. Baseline and HU-induced HbF expression are both inherited complex traits. In children with SCD, baseline HbF remains the best predictor of drug-induced levels, but this accounts for only a portion of the induction. A limited number of validated genetic loci are strongly associated with higher baseline HbF levels in SCD. For induced HbF levels, genetic approaches using candidate single-nucleotide polymorphisms (SNPs) have identified some of these same loci as being also associated with induction. However, SNP associations with induced HbF are only partially independent of baseline levels. Additional approaches to understanding the impact of HU on HbF and its other therapeutic effects on SCD include pharmacokinetic, gene expression-based, and epigenetic analyses in patients and through studies in existing murine models for SCD. Understanding the genetic and other factors underlying the variability in therapeutic effects of HU for pediatric SCD is critical for prospectively predicting good responders and for designing other effective therapies.
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Affiliation(s)
- Nancy S. Green
- Division of Pediatric Hematology, Department of Pediatrics, Columbia University, New York, NY, United States
| | - Sandra Barral
- G.H.Sergievsky Center, Department of Neurology, Columbia University, New York, NY, United States
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