title: Expression of signal transduction proteins during the differentiation of primary human erythroblasts.
abstract: The high number (>10(8-10)) of primary human pro-erythroblasts (CD36high/CD235alow) obtainable in HEMA culture (Migliaccio et al., 2002) is exploited here to analyse the expression of proteins implicated in erythropoietin (EPO)-signalling (STATs, PI-3K, and PLCs) during the process of erythroid maturation. Human pro-erythroblasts progressed in 4 days of culture with EPO into basophilic- (CD36high/CD235amedium, 24 h), polychromatic-(CD36high/CD235ahigh, 48 h), and, finally, orthochromatic-(CD36low/CD235ahigh, 72-96 h) erythroblasts. During this maturation, STAT-1 was expressed up to the orthochromatic stage, expression of STAT-5, as well as of its target proteins BclxL and IRF1, remained constant up to 48 h (polychromatic-erythroblasts) but decreased by 96 h (orthochromatic-erythroblasts), while that of STAT-3 decreased constantly from 24 h on and became undetectable by 96 h. Expression of PI-3K rapidly decreased with differentiation since only 50% of original protein levels were detected by 48 h. On the other hand, among the members of PLC families investigated, PLC beta4 was not expressed, PLC beta2, delta1, and gamma2 were expressed at constant levels throughout the maturation process, while expression of PLC beta3 and of PLC gamma1 decreased, as PI-3K, by 24 h and that of PLC beta1 was induced by 6 h and became undetectable by 24 h. In conclusion, these data depict the dynamic signalling scenario associated with the maturation of erythroid cells and provide the first indication that members of PLC families (PLC beta1, beta3, and gamma1) might be involved in the control of erythroid differentiation in humans.
authors.affiliation: Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore Sanità, Rome, Italy.
authors.forename: Viviana
authors.initials: V
authors.lastname: di Giacomo
authors.forename: Alessandro
authors.initials: A
authors.lastname: Matteucci
authors.forename: Emilia
authors.initials: E
authors.lastname: Stellacci
authors.forename: Angela
authors.initials: A
authors.lastname: Battistini
authors.forename: Angela
authors.initials: A
authors.lastname: Di Baldassarre
authors.forename: Silvano
authors.initials: S
authors.lastname: Capitani
authors.forename: Elena
authors.initials: E
authors.lastname: Alfani
authors.forename: Anna Rita
authors.initials: AR
authors.lastname: Migliaccio
authors.forename: Lucio
authors.initials: L
authors.lastname: Cocco
authors.forename: Giovanni
authors.initials: G
authors.lastname: Migliaccio
mesh_terms: D015703:Antigens, CD / Q000378:metabolism; D015415:Biomarkers; D002454:Cell Differentiation; D048430:Cell Shape; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004900:Erythroblasts / Q000166:cytology / Q000502:physiology*; D004920:Erythropoiesis; D006801:Humans; D050856:Interferon Regulatory Factor-1; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D050794:STAT1 Transcription Factor; D015398:Signal Transduction; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D010738:Type C Phospholipases / Q000235:genetics / Q000378:metabolism; D051020:bcl-X Protein
chemical_list: D015703:Antigens, CD; C494811:BCL2L1 protein, human; D015415:Biomarkers; D004268:DNA-Binding Proteins; C494257:IRF1 protein, human; D050856:Interferon Regulatory Factor-1; D007527:Isoenzymes; D010750:Phosphoproteins; D019253:Proto-Oncogene Proteins c-bcl-2; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D015534:Trans-Activators; D051020:bcl-X Protein; D019869:Phosphatidylinositol 3-Kinases; D010738:Type C Phospholipases