Esigned the experiments: HS FZ. Performed the experiments: HS FZ. Analyzed the data: HS FZ. Wrote the paper: HS FZ.
Inherited mutations or deletions at the HBB gene locus on chromosome 11p15.4 cause beta-thalassemia [1]. The heterozygous state is prevalent in tropical regions and likely plays a role in protecting carrier populations from malarial disease [2]. There are over 200 mutations or deletions that cause a beta-thalassemia phenotype [3]. Homozygous or compound heterozygous inheritance causes more severe reductions in beta-globin gene and protein expression. When hemoglobin production becomes insufficient for the delivery of oxygen, regular and lifelong erythrocyte transfusions are required. Microcytic hypochromic anemia usually develops in betathalassemia during infancy or early BTZ043 childhood with the developmental loss of fetal hemoglobin expression. The pathophysiology of this anemia is multifactorial and includes shortened survival of erythrocytes in the peripheral blood. In addition, so-called “ineffective” erythropoiesis develops despite increased hPTH (1-34) price erythropoietin levels and packing of the marrow with erythroblasts. In human beta-thalassemia, apoptotic cell death [4] is a major mechanism by which there is a decrease in the number of generated erythroblast precursor cells [5]. Studies of the molecular and cellular features of the betathalassemia phenotype are aimed toward novel diagnostic andtherapeutic strategies. Efforts have been made to better understand the causes of ineffective erythropoiesis with clinical goals of improving red cell production and reducing the burden of iron overload. Our understanding of this cellular process remains vague, in part, because bone marrow sampling is not regularly performed. Major differences in the clinical phenotype also exist between thalassemic patients with identical globin mutations. As an alternative for in vivo studies, murine models of thalassemia were developed, but differences between the murine models and human beta-thalassemia major were reported [6?]. In this study, a synthetic model for human beta-thalassemia erythropoiesis is reported as an experimental bridge between the non-human models and the clinic. Lentiviral-mediated knockdown of betaglobin expression was 1407003 studied using CD34+ cells obtained from healthy human adults. This model reiterates several features of ineffective erythropoiesis in human beta-thalassemia including accumulation of insoluble alpha-globin protein and apoptosis at the polychromatophilic stage of differentiation.Materials and Methods Ethics StatementApproval for the research protocol and consent documents pertaining to all studies using primary erythroblasts was granted byA Synthetic Model of Beta-Thalassemiathe Intramural National Institute of Diabetes and Digestive and Kidney Diseases Institutional Review Board. Written informed consent was obtained from all research subjects prior to participation in this study.Quantitative PCR Analyses for Gene ExpressionOn culture day 14, total RNA from three separate donors was extracted using the RNeasy Plus kit (Qiagen, Valentia, CA) and reverse transcribed using SuperScript III reverse transcriptase with Oligo-dT(20) and RNase H treatment (Invitrogen). Real-time PCR was performed on the ABI PRISM 7700 sequence detection system instrument and software (Applied Biosystems, Foster City, CA), using the manufacturer’s recommended conditions. QPCR assays and PCR conditions were performed with primers, probes, or Assa.Esigned the experiments: HS FZ. Performed the experiments: HS FZ. Analyzed the data: HS FZ. Wrote the paper: HS FZ.
Inherited mutations or deletions at the HBB gene locus on chromosome 11p15.4 cause beta-thalassemia [1]. The heterozygous state is prevalent in tropical regions and likely plays a role in protecting carrier populations from malarial disease [2]. There are over 200 mutations or deletions that cause a beta-thalassemia phenotype [3]. Homozygous or compound heterozygous inheritance causes more severe reductions in beta-globin gene and protein expression. When hemoglobin production becomes insufficient for the delivery of oxygen, regular and lifelong erythrocyte transfusions are required. Microcytic hypochromic anemia usually develops in betathalassemia during infancy or early childhood with the developmental loss of fetal hemoglobin expression. The pathophysiology of this anemia is multifactorial and includes shortened survival of erythrocytes in the peripheral blood. In addition, so-called “ineffective” erythropoiesis develops despite increased erythropoietin levels and packing of the marrow with erythroblasts. In human beta-thalassemia, apoptotic cell death [4] is a major mechanism by which there is a decrease in the number of generated erythroblast precursor cells [5]. Studies of the molecular and cellular features of the betathalassemia phenotype are aimed toward novel diagnostic andtherapeutic strategies. Efforts have been made to better understand the causes of ineffective erythropoiesis with clinical goals of improving red cell production and reducing the burden of iron overload. Our understanding of this cellular process remains vague, in part, because bone marrow sampling is not regularly performed. Major differences in the clinical phenotype also exist between thalassemic patients with identical globin mutations. As an alternative for in vivo studies, murine models of thalassemia were developed, but differences between the murine models and human beta-thalassemia major were reported [6?]. In this study, a synthetic model for human beta-thalassemia erythropoiesis is reported as an experimental bridge between the non-human models and the clinic. Lentiviral-mediated knockdown of betaglobin expression was 1407003 studied using CD34+ cells obtained from healthy human adults. This model reiterates several features of ineffective erythropoiesis in human beta-thalassemia including accumulation of insoluble alpha-globin protein and apoptosis at the polychromatophilic stage of differentiation.Materials and Methods Ethics StatementApproval for the research protocol and consent documents pertaining to all studies using primary erythroblasts was granted byA Synthetic Model of Beta-Thalassemiathe Intramural National Institute of Diabetes and Digestive and Kidney Diseases Institutional Review Board. Written informed consent was obtained from all research subjects prior to participation in this study.Quantitative PCR Analyses for Gene ExpressionOn culture day 14, total RNA from three separate donors was extracted using the RNeasy Plus kit (Qiagen, Valentia, CA) and reverse transcribed using SuperScript III reverse transcriptase with Oligo-dT(20) and RNase H treatment (Invitrogen). Real-time PCR was performed on the ABI PRISM 7700 sequence detection system instrument and software (Applied Biosystems, Foster City, CA), using the manufacturer’s recommended conditions. QPCR assays and PCR conditions were performed with primers, probes, or Assa.