title: Activin A/erythroid differentiation factor is induced during human monocyte activation.
abstract: Activin A/erythroid differentiation factor (EDF), a dimeric polypeptide hormone composed of two beta A subunits, regulates growth and erythroid differentiation of human hematopoietic progenitor and erythroleukemia cells. We have identified activated human peripheral blood monocytes as a natural source of activin A/EDF. In these cells, lipopolysaccharide (LPS) induced rapidly the expression of the beta A subunit mRNAs through protein kinase C-dependent transcriptional regulation. The beta A subunit mRNA expression was also increased by 1,25-dihydroxyvitamin D3, an inducer of macrophage maturation of monocytes. Western analysis with an anti-beta A antibody and an erythroid differentiation bioassay confirmed that the conditioned media of LPS-activated monocytes contained the activin A/EDF protein. We suggest that monocyte/macrophage-derived activin A/EDF may not only modulate hematopoiesis but may also act as a mediator molecule in the diverse physiologic and pathogenetic events in which these cells are involved.
authors.affiliation: Department of Bacteriology and Immunology, University of Helsinki, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Erämaa
authors.forename: M
authors.initials: M
authors.lastname: Hurme
authors.forename: U H
authors.initials: UH
authors.lastname: Stenman
authors.forename: O
authors.initials: O
authors.lastname: Ritvos
mesh_terms: D028341:Activins; D001483:Base Sequence; D002478:Cells, Cultured; D006133:Growth Substances / Q000096:biosynthesis*; D006410:Hematopoiesis; D006801:Humans; D007265:Inhibins / Q000096:biosynthesis* / Q000235:genetics; D008969:Molecular Sequence Data; D009000:Monocytes / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis
chemical_list: D006133:Growth Substances; D012333:RNA, Messenger; D028341:Activins; D007265:Inhibins