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Lance EI, Faulcon LM, Fu Z, Yang J, Whyte-Stewart D, Strouse JJ, Barron-Casella E, Jones K, Van Eyk JE, Casella JF, Everett AD. Proteomic discovery in sickle cell disease: Elevated neurogranin levels in children with sickle cell disease. Proteomics Clin Appl 2021; 15:e2100003. [PMID: 33915030 PMCID: PMC8666096 DOI: 10.1002/prca.202100003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 04/06/2021] [Accepted: 04/26/2021] [Indexed: 01/12/2023]
Abstract
PURPOSE Sickle cell disease (SCD) is an inherited hemoglobinopathy that causes stroke and silent cerebral infarct (SCI). Our aim was to identify markers of brain injury in SCD. EXPERIMENTAL DESIGN Plasma proteomes were analyzed using a sequential separation approach of hemoglobin (Hb) and top abundant plasma protein depletion, followed by reverse phase separation of intact proteins, trypsin digestion, and tandem mass spectrometry. We compared plasma proteomes of children with SCD with and without SCI in the Silent Cerebral Infarct Multi-Center Clinical Trial (SIT Trial) to age-matched, healthy non-SCD controls. RESULTS From the SCD group, 1172 proteins were identified. Twenty-five percent (289/1172) were solely in the SCI group. Twenty-five proteins with enriched expression in the human brain were identified in the SCD group. Neurogranin (NRGN) was the most abundant brain-enriched protein in plasma of children with SCD. Using a NRGN sandwich immunoassay and SIT Trial samples, median NRGN levels were higher at study entry in children with SCD (0.28 ng/mL, N = 100) compared to control participants (0.12 ng/mL, N = 25, p < 0.0004). CONCLUSIONS AND CLINICAL RELEVANCE NRGN levels are elevated in children with SCD. NRGN and other brain-enriched plasma proteins identified in plasma of children with SCD may provide biochemical evidence of neurological injury.
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Affiliation(s)
- Eboni I Lance
- Department of Neurodevelopmental Medicine, Kennedy Krieger Institute, Baltimore, Maryland, USA.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Lisa M Faulcon
- Food and Drug Administration, Silver Spring, Maryland, USA
| | - Zongming Fu
- Division of Pediatric Hematology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Jun Yang
- Division of Pediatric Cardiology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Donna Whyte-Stewart
- Division of Pediatric Hematology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - John J Strouse
- Division of Pediatric Hematology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Division of Hematology, Department of Medicine, Duke University School of Medicine, Durham, North Carolina
| | - Emily Barron-Casella
- Division of Pediatric Hematology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Kimberly Jones
- Division of Pediatric Hematology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Jennifer E Van Eyk
- Division of Cardiology, Department of Internal Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,The Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - James F Casella
- Division of Pediatric Hematology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Allen D Everett
- Division of Pediatric Cardiology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Lance EI, Barron-Casella E, Everett AD, Casella JF. Brain-derived neurotrophic factor levels in pediatric sickle cell disease. Pediatr Blood Cancer 2020; 67:e28076. [PMID: 31736231 PMCID: PMC7171877 DOI: 10.1002/pbc.28076] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Revised: 10/15/2019] [Accepted: 10/21/2019] [Indexed: 12/24/2022]
Abstract
BACKGROUND Children with sickle cell disease (SCD) have an increased risk of neurological complications, particularly stroke and silent cerebral infarction (SCI). Brain-derived neurotrophic factor (BDNF) is a nerve growth factor associated with neuronal survival, synaptic plasticity, elevated transcranial Doppler (TCD) velocities and increased risk of stroke in patients with SCD. The objective of this study was to analyze plasma BDNF protein levels in children with SCD participating in the Silent Cerebral Infarct Transfusion Multi-Center Clinical Trial (SIT Trial), comparing plasma samples of children with SCD and SCI to plasma samples from children with SCD without SCI, as well as healthy pediatric control participants. PROCEDURE Entry, exit, and longitudinal blood samples were collected from 190 SIT Trial participants with SCD and healthy pediatric controls over time. BDNF levels were measured by enzyme-linked immunosorbent assay. Sample collection was not optimized for measurements of BDNF, but factors affecting BDNF levels were accounted for in analyses. RESULTS BDNF levels were significantly higher in children with SCD in comparison to healthy pediatric control subjects. BDNF levels significantly increased over time in SCD participants. BDNF levels did not show any significant associations with the presence or absence of SCI or new/progressive SCI/stroke or TCD velocities. CONCLUSIONS Plasma BDNF levels are elevated and increase over time in children with SCD. Additional studies with more longitudinal samples are needed to address the reasons for those increased levels.
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Affiliation(s)
- Eboni I. Lance
- Department of Neurology and Developmental Medicine, Kennedy Krieger Institute,Department of Neurology, the Johns Hopkins University School of Medicine
| | - Emily Barron-Casella
- Department of Pediatrics, Division of Hematology, the Johns Hopkins University School of Medicine
| | - Allen D. Everett
- Department of Pediatrics, Division of Cardiology, the Johns Hopkins University School of Medicine
| | - James F. Casella
- Department of Pediatrics, Division of Hematology, the Johns Hopkins University School of Medicine
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Lance EI, Casella JF, Everett AD, Barron-Casella E. Proteomic and biomarker studies and neurological complications of pediatric sickle cell disease. Proteomics Clin Appl 2014; 8:813-27. [PMID: 25290359 DOI: 10.1002/prca.201400069] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 08/20/2014] [Accepted: 09/30/2014] [Indexed: 01/27/2023]
Abstract
Biomarker analysis and proteomic discovery in pediatric sickle cell disease has the potential to lead to important discoveries and improve care. The aim of this review article is to describe proteomic and biomarker articles involving neurological and developmental complications in this population. A systematic review was conducted to identify relevant research publications. Articles were selected for children under the age of 21 years with the most common subtypes of sickle cell disease. Included articles focused on growth factors (platelet-derived growth factor), intra and extracellular brain proteins (glial fibrillary acidic protein, brain-derived neurotrophic factor), and inflammatory and coagulation markers (interleukin-1β, l-selectin, thrombospondin-1, erythrocyte, and platelet-derived microparticles). Positive findings include increases in plasma brain-derived neurotrophic factor and platelet-derived growth factor with elevated transcranial Dopplers velocities, increases in platelet-derived growth factor isoform AA with overt stroke, and increases in glial fibrillary acidic protein with acute brain injury. These promising potential neuro-biomarkers provide insight into pathophysiologic processes and clinical events, but their clinical utility is yet to be established. Additional proteomics research is needed, including broad-based proteomic discovery of plasma constituents and blood cell proteins, as well as urine and cerebrospinal fluid components, before, during and after neurological and developmental complications.
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Affiliation(s)
- Eboni I Lance
- Department of Neurology, Kennedy Krieger Institute, Baltimore, MD, USA; Department of Neurology, the Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Pediatrics, Division of Hematology, the Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Bhatnagar P, Barron-Casella E, Bean CJ, Milton JN, Baldwin CT, Steinberg MH, DeBaun M, Casella JF, Arking DE. Genome-wide meta-analysis of systolic blood pressure in children with sickle cell disease. PLoS One 2013; 8:e74193. [PMID: 24058526 PMCID: PMC3772989 DOI: 10.1371/journal.pone.0074193] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Accepted: 07/30/2013] [Indexed: 01/11/2023] Open
Abstract
In pediatric sickle cell disease (SCD) patients, it has been reported that higher systolic blood pressure (SBP) is associated with increased risk of a silent cerebral infarction (SCI). SCI is a major cause of neurologic morbidity in children with SCD, and blood pressure is a potential modulator of clinical manifestations of SCD; however, the risk factors underlying these complications are not well characterized. The aim of this study was to identify genetic variants that influence SBP in an African American population in the setting of SCD, and explore the use of SBP as an endo-phenotype for SCI. We conducted a genome-wide meta-analysis for SBP using two SCD cohorts, as well as a candidate screen based on published SBP loci. A total of 1,617 patients were analyzed, and while no SNP reached genome-wide significance (P-value<5.0 x 10(-8)), a number of suggestive candidate loci were identified. The most significant SNP, rs7952106 (P-value=8.57 x 10(-7)), was in the DRD2 locus on chromosome 11. In a gene-based association analysis, MIR4301 (micro-RNA4301), which resides in an intron of DRD2, was the most significant gene (P-value=5.2 x 10(-5)). Examining 27 of the previously reported SBP associated SNPs, 4 SNPs were nominally significant. A genetic risk score was constructed to assess the aggregated genetic effect of the published SBP variants, demonstrating a significant association (P=0.05). In addition, we also assessed whether these variants are associated with SCI, validating the use of SBP as an endo-phenotype for SCI. Three SNPs were nominally associated, and only rs2357790 (5' CACNB2) was significant for both SBP and SCI. None of these SNPs retained significance after Bonferroni correction. Taken together, our results suggest the importance of DRD2 genetic variation in the modulation of SBP, and extend the aggregated importance of previously reported SNPs in the modulation of SBP in an African American cohort, more specifically in children with SCD.
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Affiliation(s)
- Pallav Bhatnagar
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Emily Barron-Casella
- Department of Pediatrics, Division of Pediatric Hematology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Christopher J. Bean
- Clinical and Molecular Hemostasis Laboratory Branch, Division of Blood Disorders, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Jacqueline N. Milton
- Department of Biostatistics, Boston University School of Public Health, Boston, Massachusetts, United States of America
| | - Clinton T. Baldwin
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Martin H. Steinberg
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Michael DeBaun
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - James F. Casella
- Department of Pediatrics, Division of Pediatric Hematology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Dan E. Arking
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
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Faulcon LM, Fu Z, Dulloor P, Barron-Casella E, Savage W, Jennings JM, Van Eyk JE, Debaun M, Casella JF, Everett A. Thrombospondin-1 and L-selectin are associated with silent cerebral infarct in children with sickle cell anaemia. Br J Haematol 2013; 162:421-4. [PMID: 23672305 DOI: 10.1111/bjh.12374] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Thangarajh M, Yang G, Fuchs D, Ponisio MR, McKinstry RC, Jaju A, Noetzel MJ, Casella JF, Barron-Casella E, Hooper WC, Boulet SL, Bean CJ, Pyle ME, Payne AB, Driggers J, Trau HA, Vendt BA, Rodeghier M, DeBaun MR. Magnetic resonance angiography-defined intracranial vasculopathy is associated with silent cerebral infarcts and glucose-6-phosphate dehydrogenase mutation in children with sickle cell anaemia. Br J Haematol 2012; 159:352-9. [PMID: 22958163 DOI: 10.1111/bjh.12034] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Accepted: 07/16/2012] [Indexed: 01/02/2023]
Abstract
Silent cerebral infarct (SCI) is the most commonly recognized cause of neurological injury in sickle cell anaemia (SCA). We tested the hypothesis that magnetic resonance angiography (MRA)-defined vasculopathy is associated with SCI. Furthermore, we examined genetic variations in glucose-6-phosphate dehydrogenase (G6PD) and HBA (α-globin) genes to determine their association with intracranial vasculopathy in children with SCA. Magnetic resonance imaging (MRI) of the brain and MRA of the cerebral vasculature were available in 516 paediatric patients with SCA, enrolled in the Silent Infarct Transfusion (SIT) Trial. All patients were screened for G6PD mutations and HBA deletions. SCI were present in 41·5% (214 of 516) of SIT Trial children. The frequency of intracranial vasculopathy with and without SCI was 15·9% and 6·3%, respectively (P < 0·001). Using a multivariable logistic regression model, only the presence of a SCI was associated with increased odds of vasculopathy (P = 0·0007, odds ratio (OR) 2·84; 95% Confidence Interval (CI) = 1·55-5·21). Among male children with SCA, G6PD status was associated with vasculopathy (P = 0·04, OR 2·78; 95% CI = 1·04-7·42), while no significant association was noted for HBA deletions. Intracranial vasculopathy was observed in a minority of children with SCA, and when present, was associated with G6PD status in males and SCI.
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Affiliation(s)
- Mathula Thangarajh
- Department of Neurology and Pediatrics, Washington University School of Medicine, Saint Louis, MO, USA
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Milton JN, Sebastiani P, Solovieff N, Hartley SW, Bhatnagar P, Arking DE, Dworkis DA, Casella JF, Barron-Casella E, Bean CJ, Hooper WC, DeBaun MR, Garrett ME, Soldano K, Telen MJ, Ashley-Koch A, Gladwin MT, Baldwin CT, Steinberg MH, Klings ES. A genome-wide association study of total bilirubin and cholelithiasis risk in sickle cell anemia. PLoS One 2012; 7:e34741. [PMID: 22558097 PMCID: PMC3338756 DOI: 10.1371/journal.pone.0034741] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 03/05/2012] [Indexed: 12/31/2022] Open
Abstract
Serum bilirubin levels have been associated with polymorphisms in the UGT1A1 promoter in normal populations and in patients with hemolytic anemias, including sickle cell anemia. When hemolysis occurs circulating heme increases, leading to elevated bilirubin levels and an increased incidence of cholelithiasis. We performed the first genome-wide association study (GWAS) of bilirubin levels and cholelithiasis risk in a discovery cohort of 1,117 sickle cell anemia patients. We found 15 single nucleotide polymorphisms (SNPs) associated with total bilirubin levels at the genome-wide significance level (p value <5 × 10(-8)). SNPs in UGT1A1, UGT1A3, UGT1A6, UGT1A8 and UGT1A10, different isoforms within the UGT1A locus, were identified (most significant rs887829, p = 9.08 × 10(-25)). All of these associations were validated in 4 independent sets of sickle cell anemia patients. We tested the association of the 15 SNPs with cholelithiasis in the discovery cohort and found a significant association (most significant p value 1.15 × 10(-4)). These results confirm that the UGT1A region is the major regulator of bilirubin metabolism in African Americans with sickle cell anemia, similar to what is observed in other ethnicities.
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Affiliation(s)
- Jacqueline N. Milton
- Department of Biostatistics, Boston University School of Public Health, Boston, Massachusetts, United States of America
| | - Paola Sebastiani
- Department of Biostatistics, Boston University School of Public Health, Boston, Massachusetts, United States of America
| | - Nadia Solovieff
- Department of Biostatistics, Boston University School of Public Health, Boston, Massachusetts, United States of America
| | - Stephen W. Hartley
- Department of Biostatistics, Boston University School of Public Health, Boston, Massachusetts, United States of America
| | - Pallav Bhatnagar
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Dan E. Arking
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Daniel A. Dworkis
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - James F. Casella
- Department of Pediatrics, Division of Pediatric Hematology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Emily Barron-Casella
- Department of Pediatrics, Division of Pediatric Hematology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Christopher J. Bean
- Clinical and Molecular Hemostasis Laboratory Branch, Division of Blood Disorders, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - W. Craig Hooper
- Clinical and Molecular Hemostasis Laboratory Branch, Division of Blood Disorders, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Michael R. DeBaun
- Vanderbilt School of Medicine, Nashville, Tennessee, United States of America
| | - Melanie E. Garrett
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Karen Soldano
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Marilyn J. Telen
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Allison Ashley-Koch
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Mark T. Gladwin
- Division of Pulmonary, Allergy and Critical Care Medicine and the Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Clinton T. Baldwin
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Martin H. Steinberg
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Elizabeth S. Klings
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
- The Pulmonary Center, Boston University School of Medicine, Boston, Massachusetts, United States of America
- * E-mail:
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Savage WJ, Barron-Casella E, Fu Z, Dulloor P, Williams L, Crain BJ, White DA, Jennings JM, Van Eyk JE, Debaun MR, Everett A, Casella JF. Plasma glial fibrillary acidic protein levels in children with sickle cell disease. Am J Hematol 2011; 86:427-9. [PMID: 21523806 DOI: 10.1002/ajh.21995] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
To determine if glial fibrillary acidic protein (GFAP) is associated with brain injury in children with sickle cell disease (SCD), we measured plasma GFAP among cross-sectional groups of unselected children with SCD, subsets of children with SCD and normal brain MRI or MRI evidence of cerebral infarct, healthy pediatric controls, and adults with brain injury. Children with SCD had higher plasma GFAP than healthy pediatric controls (mean concentrations 0.14 ± 0.37 vs. 0.07 ± 0.08 ng/mL; P 5 0.003); also, 16.0% (16/100) of children with SCD and cerebral infarct had GFAP elevations above the 95th percentile of healthy pediatric controls (P 5 0.04). Although not statistically significant, children with SCD and cerebral infarct had more elevated GFAP levels than with SCD and no infarct (16/100, 16.0% vs. 14/168, 8.3%; P 5 0.07). Children with SCD and acute brain ischemia had a higher proportion of elevated GFAP than SCD children with normal MRI (3/6, 50% vs.8.3%; P 5 0.01). GFAP was associated with elevated systolic blood pressure in the preceding year and correlated positively with white blood cell count and negatively with age and performance IQ. Plasma GFAP is elevated among children with SCD and may be associated with subclinical brain injury.
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Affiliation(s)
- William J Savage
- Divisions of Transfusion Medicine and Pediatric Hematology, Johns Hopkins University School of Medicine, 600 N. Wolfe St., Baltimore, MD 21287, USA.
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Bhatnagar P, Purvis S, Barron-Casella E, DeBaun MR, Casella JF, Arking DE, Keefer JR. Genome-wide association study identifies genetic variants influencing F-cell levels in sickle-cell patients. J Hum Genet 2011; 56:316-23. [PMID: 21326311 PMCID: PMC5825003 DOI: 10.1038/jhg.2011.12] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Fetal hemoglobin (HbF) level has emerged as an important prognostic factor in sickle-cell disease (SCD) and can be measured by the proportion of HbF-containing erythrocytes (F-cells). Recently, BCL11A (zinc-finger protein) was identified as a regulator of HbF, and the strongest association signals were observed either directly for rs766432 or for correlated single-nucleotide polymorphisms (SNPs). To identify additional independently associated genetic variants, we performed a genome-wide association study (GWAS) on the proportion of F-cells in individuals of African ancestry with SCD from the Silent Infarct Transfusion (SIT) Trial cohort. Our study not only confirms the association of rs766432 (P-value <3.32 × 10(-13)), but also identifies an independent novel intronic SNP, rs7606173, associated with F-cells (P-value <1.81 × 10(-15)). The F-cell variances explained independently by these two SNPs are ∼13% (rs7606173) and ∼11% (rs766432), whereas, together they explain ∼16%. Additionally, in men, we identify a novel locus on chromosome 17, glucagon-like peptide-2 receptor (GLP2R), associated with F-cell regulation (rs12103880; P-value <3.41 × 10(-8)). GLP2R encodes a G protein-coupled receptor and involved in proliferative and anti-apoptotic cellular responses. These findings highlight the importance of denser genetic screens and suggest further exploration of the BCL11A and GLP2R loci to gain additional insight into HbF/F-cell regulation.
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Affiliation(s)
- Pallav Bhatnagar
- McKusick-Nathans Institute of Genetic Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
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Williams LM, Fu Z, Dulloor P, Yen T, Barron-Casella E, Savage W, Van Eyk JE, Casella JF, Everett A. Hemoglobin depletion from plasma: Considerations for proteomic discovery in Sickle Cell disease and other hemolytic processes. Proteomics Clin Appl 2010; 4:926-30. [DOI: 10.1002/prca.201000054] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Lu JF, Barron-Casella E, Deering R, Heinzer AK, Moser AB, deMesy Bentley KL, Wand GS, C McGuinness M, Pei Z, Watkins PA, Pujol A, Smith KD, Powers JM. The role of peroxisomal ABC transporters in the mouse adrenal gland: the loss of Abcd2 (ALDR), Not Abcd1 (ALD), causes oxidative damage. J Transl Med 2007; 87:261-72. [PMID: 17260006 DOI: 10.1038/labinvest.3700512] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
X-linked adreno-leukodystrophy is a progressive, systemic peroxisomal disorder that primarily affects the adrenal cortex, as well as myelin and axons of the central nervous system. Marked phenotypic heterogeneity does not correlate with disease-causing mutations in ABCD1, which encodes a peroxisomal membrane protein that is a member of the ABC transmembrane transporter proteins. The precise physiological functions of ABCD1 and ABCD2, a closely related peroxisomal membrane half-transporter, are unknown. The abcd1 knockout mouse does not develop the inflammatory demyelination so typical and devastating in adreno-leukodystrophy, but it does display the same lamellae and lipid profiles in adrenocortical cells under the electron microscope as the human patients. The adrenocortical cells in the mouse also exhibit immunohistochemical evidence of oxidative stress at 12 weeks but no evidence of oxidative damage. To better understand the pathogenesis of this complex disease, we evaluate the adrenal lesion of the abcd1 knockout mouse as a function of normal aging, dietary or therapeutic manipulations, and abcd genotype. The loss of abcd2 causes oxidative stress in the adrenal at 12 weeks, as judged by increased immunoreactivity for the mitochondrial manganese superoxide dismutase, in both the inner cortex and medulla. The loss of abcd2 (n=20), but not abcd1 (n=27), results in the spontaneous and premature deposition of ceroid, a known end-product of oxidative damage, predominantly in adrenal medullary cells. These data indicate that the loss of abcd2 results in greater oxidative stress in murine adrenal cells than the loss of abcd1, providing a clue to its cellular function. We also find that the adrenocortical lesion of the abcd1 knockout mouse does not produce functional impairment at ten to nineteen months or overt hypocortisolism at any age, nor does it progress histologically; these and other data align this mouse model closer to human female heterozygotes than to male ALD or AMN hemizygotes.
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Affiliation(s)
- Jyh-Feng Lu
- Johns Hopkins School of Medicine, Kennedy Krieger Institute, Baltimore, MD, USA
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Abstract
Capping of the barbed-ends of actin filaments is an important mechanism for control of the cytoskeleton. In platelets, a valuable model system, it has been thought that gelsolin was the major capping protein. We now report that platelets contain approximately 2 microM Cap Z, a calcium insensitive heterodimeric capping protein; two major and additional minor isoforms of both alpha and beta subunits are present. In lysates from resting platelets 75-80% of the Cap Z sediments with the high speed pellet, but if the platelets are activated with thrombin for 10 s, about 15% of the Cap Z leaves the pellet fraction and is found in the high speed supernatant where it is not bound to actin. This translocation of Cap Z to the supernatant is also observed when resting platelets are lysed into buffer containing 50-100 microM GTP gamma S and 10 mM EGTA. Our results suggest that release of Cap Z from some actin filaments could generate free filament barbed-ends. An increase in free barbed-ends has been reported in platelet lysates prepared shortly after thrombin activation.
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Affiliation(s)
- V T Nachmias
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia 19104-6058, USA
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Abstract
We have isolated and sequenced a portion of the gene encoding the carboxy-terminal domain (CTD) of the largest subunit of RNA polymerase II from three mammals. These mammalian sequences include one rodent and two primate CTDs. Comparisons of the new sequences to mouse and Chinese hamster show a high degree of conservation among the mammalian CTDs. Due to synonymous codon usage, the nucleotide differences between hamster, rat, ape, and human result in no amino acid changes. The amino acid sequence for the mouse CTD appears to have one different amino acid when compared to the other four sequences. Therefore, except for the one variation in mouse, all of the known mammalian CTDs have identical amino acid sequences. This is in marked contrast to the situation among more divergent species. The present study suggests that there is a strong evolutionary pressure to maintain the primary structure of the mammalian CTD.
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Affiliation(s)
- E Barron-Casella
- Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205
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