title: Effect of Tumor Necrosis Factor-Alpha on Erythropoietin and Erythropoietin Receptor-Induced Erythroid Progenitor Cell Proliferation in β-Thalassemia/Hemoglobin E Patients.
abstract: OBJECTIVE
  Thalassemia is one of the genetic diseases that cause anemia and ineffective erythropoiesis. Increased levels of several inflammatory cytokines have been reported in β-thalassemia and might contribute to ineffective erythropoiesis. However, the mechanism by which tumor necrosis factor-alpha (TNF-α) is involved in ineffective erythropoiesis in thalassemic patients remains unclear. The objective of this study is to investigate the effect of TNF-α on the erythropoietin (EPO) and erythropoietin receptor (EPOR) expression involved in proliferation of β-thalassemia/hemoglobin (Hb) E erythroid progenitor cells compared with cells from healthy subjects.
  
  
  METHODS
  CD34-positive cells were isolated from heparinized blood by using the EasySep® CD34 selection kit. Cells were then cultured with suitable culture medium in various concentrations of EPO for 14 days. The effect of TNF-α on percent cell viability was analyzed by trypan blue staining. In addition, the percentage of apoptosis and levels of EPOR protein were measured by flow cytometry.
  
  
  RESULTS
  Upon EPO treatment, a higher cell number was observed for erythroid progenitor cells from both healthy participants and β-thalassemia/Hb E patients. However, a reduction of apoptosis was found in EPO-treated cells especially for β-thalassemia/Hb E patients. Interestingly, TNF-α caused higher levels of cell apoptosis and lower levels of EPOR protein in thalassemic erythroid progenitor cells.
  
  
  CONCLUSIONS
  TNF-α caused a reduction in the level of EPOR protein and EPO-induced erythroid progenitor cell proliferation. It is possible that TNF-α could be involved in the mechanism of ineffective erythropoiesis in β-thalassemia/Hb E patients.
authors.affiliation: Mahidol University Faculty of Medical Technology, Department of Clinical Microscopy, Nakhon Pathom, Thailand E-mail: dalina.itc@mahidol.ac.th.
authors.forename: Dalina I
authors.initials: DI
authors.lastname: Tanyong
authors.forename: Prapaporn
authors.initials: P
authors.lastname: Panichob
authors.forename: Wasinee
authors.initials: W
authors.lastname: Kheansaard
authors.forename: Suthat
authors.initials: S
authors.lastname: Fucharoen
mesh_terms: D000328:Adult; D017209:Apoptosis / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D015536:Down-Regulation / Q000187:drug effects; D015672:Erythroid Precursor Cells / Q000166:cytology / Q000187:drug effects*; D004920:Erythropoiesis / Q000187:drug effects* / Q000502:physiology; D004921:Erythropoietin / Q000097:blood / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects; D006446:Hemoglobin E / Q000235:genetics; D006456:Hemoglobinuria / Q000235:genetics / Q000473:pathology*; D006579:Heterozygote; D006801:Humans; D061251:Primary Cell Culture; D017467:Receptors, Erythropoietin / Q000096:biosynthesis* / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D055815:Young Adult; D017086:beta-Thalassemia / Q000235:genetics / Q000473:pathology*
chemical_list: C554270:EPO protein, human; D017467:Receptors, Erythropoietin; D014409:Tumor Necrosis Factor-alpha; D004921:Erythropoietin; D006446:Hemoglobin E