A key developmental transition occurs in erythroid cells around the time of birth characterized by the switch from fetal to adult hemoglobin (from 1232 to 1222). This switch is of critical pathophysiologic significance for sickle cell disease and 2-thalassemia, as persistent elevations of fetal hemoglobin (HbF) levels ameliorate these diseases. Genome-wide association studies of HbF levels led to the discovery of the BCL11A transcriptional repressor as a major effector of the hemoglobin switch. BCL11A inhibition represents a promising novel strategy for HbF reactivation. Genetic variation is predicted to affect regulatory elements influencing the expression of BCL11A, and thereby HbF level. Preliminary data indicate that the BCL11A locus possesses discrete chromatin signatures. This proposal tests the hypothesis that the BCL11A locus is subject to lineage-specific and developmental stage-specific layers of epigenetic regulation. Functional variants at the BCL11A locus that affect HbF expression are likely to reside within regulatory regions.
The specific aims of this proposal are to: 1) investigate mechanisms of BCL11A transcriptional regulation promoting the fetal-to-adult developmental transition; and 2) functionally evaluate regulatory elements at the BCL11A locus. Dr. Daniel E. Bauer, M.D., Ph.D., a fellow at Children's Hospital Boston, has outlined a 5-year career development plan that will build upon his clinical background in pediatric hematology/oncology and research background in the study of hematopoiesis to establish himself as an independent investigator in pediatric hematology/oncology at a large academic medical center. Under the mentorship of Dr. Stuart H. Orkin, M.D., a recognized leader in the fields of hematopoiesis and epigenetics, Dr. Bauer seeks to apply genetic and epigenetic approaches to the study of BCL11A regulation in the physiologic hemoglobin switch. An Advisory Committee of internationally recognized experts in the field will oversee his transition to independence. This plan is ideally carried out in the Division of Hematology/Oncology at Children's Hospital Boston, given its distinguished record of training physician-scientists in a rich, collaborative, and supportive environment. At the completion of the 5-year plan, Dr. Bauer will launch a career as an independent investigator with a focus on the epigenetics of hematopoietic cell fate control using hemoglobin switching as a model. In summary, this proposal aims to investigate human genetic variation and epigenetic mechanisms that influence the regulation of the BCL11A locus within the adult erythroid context. Increased knowledge of mechanisms underlying the hemoglobin switch upstream of BCL11A will inform the development of novel therapeutics targeting HbF reactivation in sickle cell disease and ?-thalassemia. Furthermore, identifying these molecular pathways will contribute to an improved basic understanding of lineage specification and ontogeny.
Sickle cell disease and 2-thalassemia are common inherited disorders of adult hemoglobin that result in both reduced quality of life and shortened lifespan. Modifying mutations in a gene called BCL11A can ameliorate these diseases by reactivation of residual fetal hemoglobin. This proposal aims to better understand how BCL11A is turned on, with the ultimate goal of rationally designing new therapies to reactivate fetal hemoglobin in sickle cell disease and 2-thalassemia.
|Esrick, Erica B; Bauer, Daniel E (2018) Genetic therapies for sickle cell disease. Semin Hematol 55:76-86|
|Yien, Yvette Y; Shi, Jiahai; Chen, Caiyong et al. (2018) FAM210B is an erythropoietin target and regulates erythroid heme synthesis by controlling mitochondrial iron import and ferrochelatase activity. J Biol Chem 293:19797-19811|
|Vinjamur, Divya S; Bauer, Daniel E (2018) Growing and Genetically Manipulating Human Umbilical Cord Blood-Derived Erythroid Progenitor (HUDEP) Cell Lines. Methods Mol Biol 1698:275-284|
|Yamauchi, Takuji; Masuda, Takeshi; Canver, Matthew C et al. (2018) Genome-wide CRISPR-Cas9 Screen Identifies Leukemia-Specific Dependence on a Pre-mRNA Metabolic Pathway Regulated by DCPS. Cancer Cell 33:386-400.e5|
|Schoonenberg, Vivien A C; Cole, Mitchel A; Yao, Qiuming et al. (2018) CRISPRO: identification of functional protein coding sequences based on genome editing dense mutagenesis. Genome Biol 19:169|
|Lessard, Samuel; Beaudoin, Mélissa; Orkin, Stuart H et al. (2018) 14q32 and let-7 microRNAs regulate transcriptional networks in fetal and adult human erythroblasts. Hum Mol Genet 27:1411-1420|
|Canver, Matthew C; Bauer, Daniel E; Orkin, Stuart H (2017) Functional interrogation of non-coding DNA through CRISPR genome editing. Methods 121-122:118-129|
|Canver, Matthew C; Lessard, Samuel; Pinello, Luca et al. (2017) Variant-aware saturating mutagenesis using multiple Cas9 nucleases identifies regulatory elements at trait-associated loci. Nat Genet 49:625-634|
|Gundry, Michael C; Dever, Daniel P; Yudovich, David et al. (2017) Technical considerations for the use of CRISPR/Cas9 in hematology research. Exp Hematol 54:4-11|
|Hodonsky, Chani J; Jain, Deepti; Schick, Ursula M et al. (2017) Genome-wide association study of red blood cell traits in Hispanics/Latinos: The Hispanic Community Health Study/Study of Latinos. PLoS Genet 13:e1006760|
Showing the most recent 10 out of 33 publications