Effect of Tumor Necrosis Factor-Alpha on Erythropoietinand Erythropoietin Receptor-Induced Erythroid Progenitor Cell Proliferation in β Thalassemia/Hemoglobin E Patients

摘要

Objective: Thalassemia is one of the genetic diseases that cause anemia and ineffective erythropoiesis. Increased levelsof 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 thalassemicpatients remains unclear. The objective of this study is to investigate the effect of TNF-α on the erythropoietin (EPO) anderythropoietin receptor (EPOR) expression involved in proliferation of β-thalassemia/hemoglobin (Hb) E erythroid progenitorcells compared with cells from healthy subjects.Materials and Methods: CD34-positive cells were isolated from heparinized blood by using the EasySep? CD34 selectionkit. Cells were then cultured with suitable culture medium in various concentrations of EPO for 14 days. The effect of TNF-αon percent cell viability was analyzed by trypan blue staining. In addition, the percentage of apoptosis and levels of EPORprotein were measured by flow cytometry.Results: Upon EPO treatment, a higher cell number was observed for erythroid progenitor cells from both healthy participantsand 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 thalassemicerythroid progenitor cells.Conclusion: 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.