title: Tumor necrosis factor alpha inhibits erythroid differentiation in human erythropoietin-dependent cells involving p38 MAPK pathway, GATA-1 and FOG-1 downregulation and GATA-2 upregulation.
abstract: The proinflammatory cytokine tumor necrosis factor alpha (TNFalpha) has been linked to inflammation- and cancer-related anemia, which reduces both quality of life and prognosis of patients. The aim of this study was to reveal molecular mechanisms linked to the inhibition of erythroid differentiation by TNFalpha. In this study, we showed that the inhibition of erythropoietin (Epo)-mediated differentiation by TNFalpha lead to a downregulation of hemoglobin synthesis and was correlated to a modulation of key erythroid transcription factors. Thus, a reverse of the transcription factor GATA-1/GATA-2 balance normally present during erythropoiesis, as well as a downregulation of the cofactor of GATA-1, friend of GATA-1 (FOG-1), and the coregulating transcription factor nuclear factor erythroid 2 (NF-E2) was observed after TNFalpha treatment. Moreover, we showed a reduction of GATA-1/FOG-1 interaction due to a reduced transcription of GATA-1 and a proteasome-dependent FOG-1 degradation after TNFalpha treatment. These changes led to an inhibition of erythroid gene expression including Epo receptor (EpoR), alpha- and gamma-globin, erythroid-associated factor (ERAF), hydroxymethylbilane synthetase (HMBS), and glycophorin A (GPA). An analysis of distinct signaling pathway activations then revealed an activation of p38 by TNF, as well as a corresponding involvement of this mitogen-activated protein kinase (MAPK) in the cytokine-dependent inhibition of erythroid differentiation. Indeed the p38 inhibitor, SB203580, abrogated the inhibitory effect of TNFalpha on the major erythroid transcription factor GATA-1 as well as erythroid marker expression in Epo-induced TF-1 cells. Overall, these data contribute to a better understanding of cytokine-dependent anemia, by giving first hints about key erythroid transcription factor modulations after TNFalpha treatment as well as an involvement of p38 in the inhibition of erythroid differentiation.
authors.affiliation: Laboratoire de Biologie Moléculaire et Cellulaire du Cancer, Hôpital Kirchberg, 9 rue Edward Steichen, L-2540 Luxembourg, Luxembourg.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Buck
authors.forename: Franck
authors.initials: F
authors.lastname: Morceau
authors.forename: Silvia
authors.initials: S
authors.lastname: Cristofanon
authors.forename: Caroline
authors.initials: C
authors.lastname: Heintz
authors.forename: Sébastien
authors.initials: S
authors.lastname: Chateauvieux
authors.forename: Simone
authors.initials: S
authors.lastname: Reuter
authors.forename: Mario
authors.initials: M
authors.lastname: Dicato
authors.forename: Marc
authors.initials: M
authors.lastname: Diederich
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D045744:Cell Line, Tumor; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology; D004920:Erythropoiesis / Q000187:drug effects / Q000502:physiology*; D004921:Erythropoietin / Q000235:genetics / Q000378:metabolism; D050982:GATA1 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D050989:GATA2 Transcription Factor / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D004915:Leukemia, Erythroblastic, Acute / Q000235:genetics / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*
chemical_list: D050982:GATA1 Transcription Factor; C494688:GATA1 protein, human; D050989:GATA2 Transcription Factor; D009687:Nuclear Proteins; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; C498432:ZFPM1 protein, human; D004921:Erythropoietin; D048051:p38 Mitogen-Activated Protein Kinases