1
|
Ellsworth P, Pawlinski IJ, Sielaty R, Ilich A, Prokopenko Y, Moonla C, Monroe DM, Pawlinski R, Key NS. Hypertonicity and/or acidosis induce marked rheological changes under hypoxic conditions in sickle trait red blood cells. Br J Haematol 2024. [PMID: 39054759 DOI: 10.1111/bjh.19669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 07/15/2024] [Indexed: 07/27/2024]
Abstract
Deformability and sickling of red blood cells (RBCs) from individuals with sickle cell trait (SCT) was evaluated under harsh biophysical conditions that mimic certain vascular beds in vivo. RBC deformability in osmotic-gradient ektacytometry was decreased in HbAS (SCT) compared to HbAA (wild-type) RBCs at supraphysiological osmolalities. RBC deformability was also measured by oxygen-gradient ektacytometry. Whereas RBC sickling was not observed under isotonic and neutral pH conditions, hypertonicity and acidosis alone or in combination induced reversible sickling of SCT RBC. These data suggest that hyperosmolality and/or acidosis enhance hypoxia-induced sickling of SCT RBC.
Collapse
Affiliation(s)
- Patrick Ellsworth
- UNC Blood Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Division of Hematology, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Izabela J Pawlinski
- UNC Blood Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Rachel Sielaty
- UNC Blood Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Anton Ilich
- UNC Blood Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Yuriy Prokopenko
- UNC Blood Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Chatphatai Moonla
- UNC Blood Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Medicine and Center of Excellence in Translational Hematology, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Bangkok, Thailand
| | - Dougald M Monroe
- UNC Blood Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Division of Hematology, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Rafal Pawlinski
- UNC Blood Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Division of Hematology, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Nigel S Key
- UNC Blood Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Division of Hematology, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| |
Collapse
|
2
|
Kirkham JK, Estepp JH, Weiss MJ, Rashkin SR. Genetic Variation and Sickle Cell Disease Severity: A Systematic Review and Meta-Analysis. JAMA Netw Open 2023; 6:e2337484. [PMID: 37851445 PMCID: PMC10585422 DOI: 10.1001/jamanetworkopen.2023.37484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 08/30/2023] [Indexed: 10/19/2023] Open
Abstract
Importance Sickle cell disease (SCD) is a monogenic disorder, yet clinical outcomes are influenced by additional genetic factors. Despite decades of research, the genetics of SCD remain poorly understood. Objective To assess all reported genetic modifiers of SCD, evaluate the design of associated studies, and provide guidelines for future analyses according to modern genetic study recommendations. Data Sources PubMed, Web of Science, and Scopus were searched through May 16, 2023, identifying 5290 publications. Study Selection At least 2 reviewers identified 571 original, peer-reviewed English-language publications reporting genetic modifiers of human SCD phenotypes, wherein the outcome was not treatment response, and the comparison was not between SCD subtypes or including healthy controls. Data Extraction and Synthesis Data relevant to all genetic modifiers of SCD were extracted, evaluated, and presented following STREGA and PRISMA guidelines. Weighted z score meta-analyses and pathway analyses were conducted. Main Outcomes and Measures Outcomes were aggregated into 25 categories, grouped as acute complications, chronic conditions, hematologic parameters or biomarkers, and general or mixed measures of SCD severity. Results The 571 included studies reported on 29 670 unique individuals (50% ≤ 18 years of age) from 43 countries. Of the 17 757 extracted results (4890 significant) in 1552 genes, 3675 results met the study criteria for meta-analysis: reported phenotype and genotype, association size and direction, variability measure, sample size, and statistical test. Only 173 results for 62 associations could be cross-study combined. The remaining associations could not be aggregated because they were only reported once or methods (eg, study design, reporting practice) and genotype or phenotype definitions were insufficiently harmonized. Gene variants regulating fetal hemoglobin and α-thalassemia (important markers for SCD severity) were frequently identified: 19 single-nucleotide variants in BCL11A, HBS1L-MYB, and HBG2 were significantly associated with fetal hemoglobin (absolute value of Z = 4.00 to 20.66; P = 8.63 × 10-95 to 6.19 × 10-5), and α-thalassemia deletions were significantly associated with increased hemoglobin level and reduced risk of albuminuria, abnormal transcranial Doppler velocity, and stroke (absolute value of Z = 3.43 to 5.16; P = 2.42 × 10-7 to 6.00 × 10-4). However, other associations remain unconfirmed. Pathway analyses of significant genes highlighted the importance of cellular adhesion, inflammation, oxidative and toxic stress, and blood vessel regulation in SCD (23 of the top 25 Gene Ontology pathways involve these processes) and suggested future research areas. Conclusions and Relevance The findings of this comprehensive systematic review and meta-analysis of all published genetic modifiers of SCD indicated that implementation of standardized phenotypes, statistical methods, and reporting practices should accelerate discovery and validation of genetic modifiers and development of clinically actionable genetic profiles.
Collapse
Affiliation(s)
- Justin K. Kirkham
- Department of Oncology, St Jude Children’s Research Hospital, Memphis, Tennessee
| | - Jeremie H. Estepp
- Department of Hematology, St Jude Children’s Research Hospital, Memphis, Tennessee
- Department of Global Pediatric Medicine, St Jude Children’s Research Hospital, Memphis, Tennessee
- Now with Agios Pharmaceuticals, Cambridge, Massachusetts
| | - Mitch J. Weiss
- Department of Hematology, St Jude Children’s Research Hospital, Memphis, Tennessee
| | - Sara R. Rashkin
- Department of Hematology, St Jude Children’s Research Hospital, Memphis, Tennessee
| |
Collapse
|
3
|
Pincez T, Lo KS, D'Orengiani ALPHD, Garrett ME, Brugnara C, Ashley-Koch AE, Telen MJ, Galacteros F, Joly P, Bartolucci P, Lettre G. Variation and impact of polygenic hematologic traits in monogenic sickle cell disease. Haematologica 2023; 108:870-881. [PMID: 36226494 PMCID: PMC9973495 DOI: 10.3324/haematol.2022.281180] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Indexed: 11/09/2022] Open
Abstract
Several of the complications observed in sickle cell disease (SCD) are influenced by variation in hematologic traits (HT), such as fetal hemoglobin (HbF) level and neutrophil count. Previous large-scale genome-wide association studies carried out in largely healthy individuals have identified thousands of variants associated with HT, which have then been used to develop multi-ancestry polygenic trait scores (PTS). Here, we tested whether these PTS associate with HT in SCD patients and if they can improve statistical models associated with SCD-related complications. In 2,056 SCD patients, we found that the PTS predicted less HT variance than in non-SCD individuals of African ancestry. This was particularly striking at the Duffy/DARC locus, where we observed an epistatic interaction between the SCD genotype and the Duffy null variant (rs2814778) that led to a two-fold weaker effect on neutrophil count. PTS for these HT which are measured as part of routine practice were not associated with complications in SCD. In contrast, we found that a simple PTS for HbF that includes only six variants explained a large fraction of the phenotypic variation (20.5-27.1%), associated with acute chest syndrome and stroke risk, and improved the statistical modeling of the vaso-occlusive crisis rate. Using Mendelian randomization, we found that increasing HbF by 4.8% reduces stroke risk by 39% (P=0.0006). Taken together, our results highlight the importance of validating PTS in large diseased populations before proposing their implementation in the context of precision medicine initiatives.
Collapse
Affiliation(s)
- Thomas Pincez
- Montreal Heart Institute, Montreal, Quebec, Canada; Department of Pediatrics, Division of Pediatric Hematology-Oncology, Charles-Bruneau Cancer Center, CHU Sainte-Justine, Universite de Montreal, Montreal, Quebec
| | - Ken Sin Lo
- Montreal Heart Institute, Montreal, Quebec
| | | | - Melanie E Garrett
- Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC
| | - Carlo Brugnara
- Department of Laboratory Medicine, Boston Children's Hospital, Boston, MA
| | | | - Marilyn J Telen
- Department of Medicine, Division of Hematology, Duke University Medical Center, Durham, NC
| | - Frederic Galacteros
- Red Cell Genetic Disease Unit, Hopital Henri-Mondor, Assistance Publique-Hopitaux de Paris (AP-HP), Universite Paris Est, IMRB - U955 - Equipe no 2, Creteil
| | - Philippe Joly
- Unite Fonctionnelle 34445 'Biochimie des Pathologies Erythrocytaires', Laboratoire de Biochimie et Biologie Moleculaire Grand-Est, Groupement Hospitalier Est, Hospices Civils de Lyon, Bron, France; Laboratoire Inter-Universitaire de Biologie de la Motricite (LIBM) EA7424, Equipe 'Biologie Vasculaire et du Globule Rouge', Universite Claude Bernard Lyon 1, Comite d'Universites et d'Etablissements (COMUE), Lyon
| | - Pablo Bartolucci
- Red Cell Genetic Disease Unit, Hopital Henri-Mondor, Assistance Publique-Hopitaux de Paris (AP-HP), Universite Paris Est, IMRB - U955 - Equipe no 2, Creteil
| | - Guillaume Lettre
- Montreal Heart Institute, Montreal, Quebec, Canada; Department of Medicine, Faculty of Medicine, Universite de Montreal, Montreal, Quebec.
| |
Collapse
|
4
|
Goreke U, Bode A, Yaman S, Gurkan UA, Durmus NG. Size and density measurements of single sickle red blood cells using microfluidic magnetic levitation. LAB ON A CHIP 2022; 22:683-696. [PMID: 35094036 PMCID: PMC9053311 DOI: 10.1039/d1lc00686j] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Single cells have unique biophysical signatures that can rapidly change during various disease states. For instance, cellular density is an inherent property differing between cell types. Characterizing changes in fundamental density properties down to the single-cell level can reveal sub-populations in pathological states. Here, we have developed a microfluidic, magnetic levitation-based assay (MagDense) that detects minute density differences of individual red blood cells (RBCs) down to 0.0001 g mL-1 resolution. This assay fractionates RBCs based on their density profiles in a non-ionic paramagnetic medium flowing in a capillary microchannel placed between magnets with same poles facing each other. Based on precisely measured levitation height and density of individual RBCs at their specific equilibrium state, we demonstrated that MagDense can accurately analyze the density of sickle hemoglobin (HbS)-containing RBCs and normal hemoglobin (HbA)-containing RBCs. In addition, the precise density and cell size measurements at the single cell level showed three different sub-populations of RBCs in blood samples from individuals with homozygous sickle cell disease receiving blood transfusions; where less dense, HbA-containing RBCs levitated higher, while the denser, HbS-containing RBCs levitated lower. We compared the mean RBC densities of sickle cell disease subjects with healthy controls and found distinctly separated bands of RBC density for each group denoting the likely range of cell densities seen in the blood samples. The high resolution of our method enabled measurement of deviation from the mean RBC density. Moreover, we introduced a new term as a measure of density dispersion, "RBC levitational density width, RLDW". Mean RBC density in sickle cell disease associated with hemoglobin from complete blood count (p = 0.032, linear regression) and RLDW associated with absolute reticulocyte count (ARC) and RBC distribution width (RDW) from complete blood count (p = 0.002 for ARC and p = 003 for RDW, linear regression). Our magnetic levitation-based assay enables rapid, accurate, density-based imaging, profiling and label-free monitoring of single RBCs. Our approach can be broadly applicable to investigate blood cell disorders and the effects of emerging pharmacological and curative therapies in patient outcomes.
Collapse
Affiliation(s)
- Utku Goreke
- Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Allison Bode
- Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, OH, USA
- Department of Hematology and Oncology, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Sena Yaman
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, Stanford University, Stanford, CA 94304, USA.
| | - Umut A Gurkan
- Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, OH, USA
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA.
| | - Naside Gozde Durmus
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, Stanford University, Stanford, CA 94304, USA.
| |
Collapse
|
5
|
Potential causal role of l-glutamine in sickle cell disease painful crises: A Mendelian randomization analysis. Blood Cells Mol Dis 2020; 86:102504. [PMID: 32949984 DOI: 10.1016/j.bcmd.2020.102504] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 09/09/2020] [Accepted: 09/09/2020] [Indexed: 01/12/2023]
Abstract
In a recent clinical trial, the metabolite l-glutamine was shown to reduce painful crises in sickle cell disease (SCD) patients. To support this observation and identify other metabolites implicated in SCD clinical heterogeneity, we profiled 129 metabolites in the plasma of 705 SCD patients. We tested correlations between metabolite levels and six SCD-related complications (painful crises, cholecystectomy, retinopathy, leg ulcer, priapism, aseptic necrosis) or estimated glomerular filtration rate (eGFR), and used Mendelian randomization (MR) to assess causality. We found a potential causal relationship between l-glutamine levels and painful crises (N = 1278, odds ratio (OR) [95% confidence interval] = 0.68 [0.52-0.89], P = 0.0048). In two smaller SCD cohorts (N = 299 and 406), the protective effect of l-glutamine was observed (OR = 0.82 [0.50-1.34]), although the MR result was not significant (P = 0.44). We identified 66 significant correlations between the levels of other metabolites and SCD-related complications or eGFR. We tested these correlations for causality using MR analyses and found no significant causal relationship. The baseline levels of quinolinic acid were associated with prospectively ascertained survival in SCD patients, and this effect was dependent on eGFR. Metabolomics provide a promising approach to prioritize small molecules that may serve as biomarkers or drug targets in SCD.
Collapse
|
6
|
Steinberg MH, Kumar S, Murphy GJ, Vanuytsel K. Sickle cell disease in the era of precision medicine: looking to the future. EXPERT REVIEW OF PRECISION MEDICINE AND DRUG DEVELOPMENT 2019; 4:357-367. [PMID: 33015364 PMCID: PMC7531762 DOI: 10.1080/23808993.2019.1688658] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 10/31/2019] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Sickle cell anemia is a mendelian disease that is noted for the heterogeneity of its clinical expression. Because of this, providing an accurate prognosis has been a longtime quest. AREAS COVERED Reviewed are the benefits and shortcomings of testing for the major modulators of the severity of disease, like fetal hemoglobin and α thalassemia, along with studies that have attempted to link genetic variation with sub-phenotypes of disease in a predictive fashion. Induced pluripotent stem cells driven to differentiate into erythroid precursor cells provide another area for potential patient-specific drug testing. EXPERT OPINION Fetal hemoglobin is the strongest modulator of sickle cell anemia but simply measuring its blood levels is an insufficient means of forecasting an individual's prognosis. A more precise method would be to know the distribution of fetal hemoglobin levels across the population of red cells, an assay not yet available. Prognostic measures have been developed using genetic and other signatures, but their predictive value is suboptimal. Widely applicable assays must be developed to allow a tailored approach to using the several new treatments that are likely to be available in the near future.
Collapse
Affiliation(s)
- Martin H Steinberg
- Department of Medicine, Division of Hematology/Oncology, Center of Excellence for Sickle Cell Disease and Center for Regenerative Medicine, Boston University School of Medicine and Boston Medical Center, Boston MA
| | - Sara Kumar
- Department of Medicine, Division of Hematology/Oncology, Center of Excellence for Sickle Cell Disease and Center for Regenerative Medicine, Boston University School of Medicine and Boston Medical Center, Boston MA
| | - George J. Murphy
- Department of Medicine, Division of Hematology/Oncology, Center of Excellence for Sickle Cell Disease and Center for Regenerative Medicine, Boston University School of Medicine and Boston Medical Center, Boston MA
| | - Kim Vanuytsel
- Department of Medicine, Division of Hematology/Oncology, Center of Excellence for Sickle Cell Disease and Center for Regenerative Medicine, Boston University School of Medicine and Boston Medical Center, Boston MA
| |
Collapse
|
7
|
Shmukler BE, Rivera A, Bhargava P, Nishimura K, Hsu A, Kim EH, Trudel M, Rust MB, Hubner CA, Brugnara C, Alper SL. Combined genetic disruption of K-Cl cotransporters and Gardos channel KCNN4 rescues erythrocyte dehydration in the SAD mouse model of sickle cell disease. Blood Cells Mol Dis 2019; 79:102346. [PMID: 31352162 PMCID: PMC6744291 DOI: 10.1016/j.bcmd.2019.102346] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 07/09/2019] [Accepted: 07/09/2019] [Indexed: 10/26/2022]
Abstract
Excessive red cell dehydration contributes to the pathophysiology of sickle cell disease (SCD). The densest fraction of sickle red cells (with the highest corpuscular hemoglobin concentration) undergoes the most rapid polymerization of deoxy-hemoglobin S, leading to accelerated cell sickling and increased susceptibility to endothelial activation, red cell adhesion, and vaso-occlusion. Increasing red cell volume in order to decrease red cell density can thus serve as an adjunct therapeutic goal in SCD. Regulation of circulating mouse red cell volume and density is mediated largely by the Gardos channel, KCNN4, and the K-Cl cotransporters, KCC3 and KCC1. Whereas inhibition of the Gardos channel in subjects with sickle cell disease increased red cell volume, decreased red cell density, and improved other hematological indices in subjects with SCD, specific KCC inhibitors have not been available for testing. We therefore investigated the effect of genetic inactivation of KCC3 and KCC1 in the SAD mouse model of sickle red cell dehydration, finding decreased red cell density and improved hematological indices. We describe here generation of mice genetically deficient in the three major red cell volume regulatory gene products, KCNN4, KCC3, and KCC1 in C57BL6 non-sickle and SAD sickle backgrounds. We show that combined loss-of-function of all three gene products in SAD mice leads to incrementally increased MCV, decreased CHCM and % hyperchromic cells, decreased red cell density (phthalate method), increased resistance to hypo-osmotic lysis, and increased cell K content. The data show that combined genetic deletion of the Gardos channel and K-Cl cotransporters in a mouse SCD model decreases red cell density and improves several hematological parameters, supporting the strategy of combined pharmacological inhibition of these ion transport pathways in the adjunct treatment of human SCD.
Collapse
Affiliation(s)
- Boris E Shmukler
- Renal Division and Vascular Biology Research Center, Beth Israel Deaconess Medical Center, Boston, MA, United States of America; Department of Laboratory Medicine, Boston Children's Hospital, Boston, MA 02115, United States of America
| | - Alicia Rivera
- Renal Division and Vascular Biology Research Center, Beth Israel Deaconess Medical Center, Boston, MA, United States of America; Department of Medicine, Harvard Medical School, Boston, MA 02115, United States of America; Department of Pathology, Harvard Medical School, Boston, MA 02115, United States of America
| | - Parul Bhargava
- Department of Laboratory Medicine, UCSF, San Francisco, CA, United States of America
| | - Katherine Nishimura
- Renal Division and Vascular Biology Research Center, Beth Israel Deaconess Medical Center, Boston, MA, United States of America
| | - Ann Hsu
- Renal Division and Vascular Biology Research Center, Beth Israel Deaconess Medical Center, Boston, MA, United States of America
| | - Edward H Kim
- Renal Division and Vascular Biology Research Center, Beth Israel Deaconess Medical Center, Boston, MA, United States of America
| | - Marie Trudel
- Institut de Recherches Cliniques de Montreal, Molecular Genetics and Development, Faculte de Medecine, Universite of Montreal, Montreal, Quebec, Canada
| | - Marco B Rust
- Institute of Physiological Chemistry, Philipps-Universität Marburg, Marburg, Germany
| | | | - Carlo Brugnara
- Department of Laboratory Medicine, Boston Children's Hospital, Boston, MA 02115, United States of America; Department of Pathology, Harvard Medical School, Boston, MA 02115, United States of America
| | - Seth L Alper
- Renal Division and Vascular Biology Research Center, Beth Israel Deaconess Medical Center, Boston, MA, United States of America; Department of Medicine, Harvard Medical School, Boston, MA 02115, United States of America.
| |
Collapse
|
8
|
Ilboudo Y, Bartolucci P, Garrett ME, Ashley-Koch A, Telen M, Brugnara C, Galactéros F, Lettre G. A common functional PIEZO1 deletion allele associates with red blood cell density in sickle cell disease patients. Am J Hematol 2018; 93:E362-E365. [PMID: 30105803 DOI: 10.1002/ajh.25245] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 08/06/2018] [Indexed: 01/25/2023]
Affiliation(s)
- Yann Ilboudo
- Faculty of Medicine; Université de Montréal; Montreal Quebec Canada
- Montreal Heart Institute; Montreal Quebec Canada
| | - Pablo Bartolucci
- Red Cell Genetic Disease Unit; Hôpital Henri-Mondor, Assistance Publique-Hôpitaux de Paris (AP-HP); Créteil France
| | - Melanie E. Garrett
- Center for Human Disease Modeling; Duke University Medical Center; Durham North Carolina
- Department of Medicine, Division of Hematology; Duke University Medical Center; Durham North Carolina
| | - Allison Ashley-Koch
- Center for Human Disease Modeling; Duke University Medical Center; Durham North Carolina
- Department of Medicine, Division of Hematology; Duke University Medical Center; Durham North Carolina
| | - Marilyn Telen
- Center for Human Disease Modeling; Duke University Medical Center; Durham North Carolina
- Department of Medicine, Division of Hematology; Duke University Medical Center; Durham North Carolina
| | - Carlo Brugnara
- Department of Laboratory Medicine; Boston Children's Hospital; Boston Massachusetts
| | - Frédéric Galactéros
- Red Cell Genetic Disease Unit; Hôpital Henri-Mondor, Assistance Publique-Hôpitaux de Paris (AP-HP); Créteil France
| | - Guillaume Lettre
- Faculty of Medicine; Université de Montréal; Montreal Quebec Canada
- Montreal Heart Institute; Montreal Quebec Canada
| |
Collapse
|
9
|
Abstract
The primary β-globin gene mutation that causes sickle cell disease (SCD) has significant pathophysiological consequences that result in hemolytic events and the induction of the inflammatory processes that ultimately lead to vaso-occlusion. In addition to their role in the initiation of the acute painful vaso-occlusive episodes that are characteristic of SCD, inflammatory processes are also key components of many of the complications of the disease including autosplenectomy, acute chest syndrome, pulmonary hypertension, leg ulcers, nephropathy and stroke. We, herein, discuss the events that trigger inflammation in the disease, as well as the mechanisms, inflammatory molecules and cells that propagate these inflammatory processes. Given the central role that inflammation plays in SCD pathophysiology, many of the therapeutic approaches currently under pre-clinical and clinical development for the treatment of SCD endeavor to counter aspects or specific molecules of these inflammatory processes and it is possible that, in the future, we will see anti-inflammatory drugs being used either together with, or in place of, hydroxyurea in those SCD patients for whom hematopoietic stem cell transplants and evolving gene therapies are not a viable option.
Collapse
Affiliation(s)
- Nicola Conran
- Hematology Center, University of Campinas - UNICAMP, Cidade Universitária, Campinas-SP, Brazil
| | - John D Belcher
- Department of Medicine, Division of Hematology, Oncology and Transplantation, Vascular Biology Center, University of Minnesota, Minneapolis, MN, USA
| |
Collapse
|
10
|
Chang AK, Ginter Summarell CC, Birdie PT, Sheehan VA. Genetic modifiers of severity in sickle cell disease. Clin Hemorheol Microcirc 2018; 68:147-164. [PMID: 29614629 DOI: 10.3233/ch-189004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Sickle cell disease (SCD) is one of the most common single disease disorders world-wide. It is remarkable for its clinical heterogeneity, even among individuals with identical genotypes. Some individuals experience morbidity and mortality in early childhood, while others have a relatively mild course, and normal or near normal life expectancy. Many clinical complications are associated with SCD; most notably frequent pain episodes, stroke, acute chest syndrome, avascular necrosis, nephropathy, retinopathy and pulmonary hypertension. While the effects of higher fetal hemoglobin (HbF) levels, UGTA1A polymorphisms, alpha-thalassemia and G6PD deficiency on SCD has been extensively studied, these variables do not explain all of the clinical heterogeneity of SCD. It is not known why some patients develop certain complications, and it is difficult to predict which complications a particular patient will experience. Much work has been done to identify genetic variants associated with these disease complications; many associations remain unvalidated. As the field continues to move beyond small sample collections and candidate gene approaches into whole genome sequencing and merging of samples from all over the world, we will identify more genetic variants associated with development of specific SCD related complications, and hopefully leverage this knowledge into targeted therapies.
Collapse
Affiliation(s)
- Alicia K Chang
- Department of Pediatrics, Division of Hematology/Oncology, Baylor College of Medicine, Houston, TX, USA
| | - Carly C Ginter Summarell
- Department of Pediatrics, Division of Hematology/Oncology, Baylor College of Medicine, Houston, TX, USA
| | - Parendi T Birdie
- Department of Pediatrics, Division of Hematology/Oncology, Baylor College of Medicine, Houston, TX, USA
| | - Vivien A Sheehan
- Department of Pediatrics, Division of Hematology/Oncology, Baylor College of Medicine, Houston, TX, USA
| |
Collapse
|
11
|
Abstract
Cell dehydration is a distinguishing characteristic of sickle cell disease and an important contributor to disease pathophysiology. Due to the unique dependence of Hb S polymerization on cellular Hb S concentration, cell dehydration promotes polymerization and sickling. In double heterozygosis for Hb S and C (SC disease) dehydration is the determining factor in disease pathophysiology. Three major ion transport pathways are involved in sickle cell dehydration: the K-Cl cotransport (KCC), the Gardos channel (KCNN4) and Psickle, the polymerization induced membrane permeability, most likely mediated by the mechano-sensitive ion channel PIEZO1. Each of these pathways exhibit unique characteristics in regulation by oxygen tension, intracellular and extracellular environment, and functional expression in reticulocytes and mature red cells. The unique dependence of K-Cl cotransport on intracellular Mg and the abnormal reduction of erythrocyte Mg content in SS and SC cells had led to clinical studies assessing the effect of oral Mg supplementation. Inhibition of Gardos channel by clotrimazole and senicapoc has led to Phase 1,2,3 trials in patients with sickle cell disease. While none of these studies has resulted in the approval of a novel therapy for SS disease, they have highlighted the key role played by these pathways in disease pathophysiology.
Collapse
Affiliation(s)
- Carlo Brugnara
- Department of Laboratory Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| |
Collapse
|
12
|
Abstract
The erythrocyte contains a network of pathways that regulate salt and water content in the face of extracellular and intracellular osmotic perturbations. This allows the erythrocyte to maintain a narrow range of cell hemoglobin concentration, a process critical for normal red blood cell function and survival. Primary disorders that perturb volume homeostasis jeopardize the erythrocyte and may lead to its premature destruction. These disorders are marked by clinical, laboratory, and physiologic heterogeneity. Recent studies have revealed that these disorders are also marked by genetic heterogeneity. They have implicated roles for several proteins, PIEZO1, a mammalian mechanosensory protein; GLUT1, the glucose transporter; SLC4A1, the anion transporter; RhAG, the Rh-associated glycoprotein; KCNN4, the Gardos channel; and ABCB6, an adenosine triphosphate-binding cassette family member, in the maintenance of erythrocyte volume homeostasis. Secondary disorders of erythrocyte hydration include sickle cell disease, thalassemia, hemoglobin CC, and hereditary spherocytosis, where cellular dehydration may be a significant contributor to disease pathology and clinical complications. Understanding the pathways regulating erythrocyte water and solute content may reveal innovative strategies to maintain normal volume in disorders associated with primary or secondary cellular dehydration. These mechanisms will serve as a paradigm for other cells and may reveal new therapeutic targets for disease prevention and treatment beyond the erythrocyte.
Collapse
|