title: TRAIL regulates normal erythroid maturation through an ERK-dependent pathway.
abstract: In order to investigate the biologic activity of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) on human erythropoiesis, glycophorin A (GPA)+ erythroid cells were generated in serum-free liquid phase from human cord blood (CB) CD34+ progenitor cells. The surface expression of TRAIL-R1 was weakly detectable in the early-intermediate phase of erythroid differentiation (days 4-6; dim-intermediate GPA expression), whereas a clear-cut expression of TRAIL-R2 was observed through the entire course of erythroid differentiation (up to days 12-14; bright GPA expression). On the other hand, surface TRAIL-R3 and -R4 were not detected at any culture time. Besides inducing a rapid but small increase of apoptotic cell death, which was abrogated by the pan-caspase inhibitor z-VAD-fmk, the addition of recombinant TRAIL at day 6 of culture inhibited the generation of morphologically mature erythroblasts. Among the intracellular pathways investigated, TRAIL significantly stimulated the extracellular signal-regulated kinase 1/2 (ERK1/2) but not the p38/mitogen-activated protein kinase (MAPK) or the c-Jun NH2-terminal kinase (JNK) pathway. Consistently with a key role of ERK1/2 in mediating the negative effects of TRAIL on erythroid maturation, PD98059, a pharmacologic inhibitor of the ERK pathway, but not z-VAD-fmk or SB203580, a pharmacologic inhibitor of p38/MAPK, reverted the antidifferentiative effect of TRAIL on CB-derived erythroblasts.
authors.affiliation: Dept of Morphology and Embryology, Human Anatomy Section, University of Ferrara, Via Fossato di Mortara 66, 44100 Ferrara, Italy. secchier@mail.umbi.umd.edu
authors.forename: Paola
authors.initials: P
authors.lastname: Secchiero
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Melloni
authors.forename: Markku
authors.initials: M
authors.lastname: Heikinheimo
authors.forename: Susanna
authors.initials: S
authors.lastname: Mannisto
authors.forename: Roberta
authors.initials: R
authors.lastname: Di Pietro
authors.forename: Antonio
authors.initials: A
authors.lastname: Iacone
authors.forename: Giorgio
authors.initials: G
authors.lastname: Zauli
mesh_terms: D015703:Antigens, CD / Q000097:blood; D018952:Antigens, CD34 / Q000097:blood; D017209:Apoptosis / Q000502:physiology*; D051017:Apoptosis Regulatory Proteins; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D004900:Erythroblasts / Q000166:cytology* / Q000187:drug effects; D004920:Erythropoiesis / Q000502:physiology*; D005312:Fetal Blood / Q000166:cytology*; D006412:Hematopoietic Stem Cells / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D020935:MAP Kinase Signaling System / Q000502:physiology*; D008562:Membrane Glycoproteins / Q000494:pharmacology / Q000502:physiology*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor / Q000235:genetics*; D011994:Recombinant Proteins / Q000494:pharmacology; D053221:TNF-Related Apoptosis-Inducing Ligand; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology / Q000502:physiology*
chemical_list: D015703:Antigens, CD; D018952:Antigens, CD34; D051017:Apoptosis Regulatory Proteins; D008562:Membrane Glycoproteins; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor; D011994:Recombinant Proteins; D053221:TNF-Related Apoptosis-Inducing Ligand; C105190:TNFRSF10A protein, human; C505639:TNFRSF10B protein, human; C505653:TNFSF10 protein, human; D014409:Tumor Necrosis Factor-alpha; D020928:Mitogen-Activated Protein Kinases