title: Role of CD34 antigen in myeloid differentiation of human hematopoietic progenitor cells.
abstract: CD34 is a transmembrane protein that is strongly expressed on hematopoietic stem/progenitor cells (HSCs); despite its importance as a marker of HSCs, its function is still poorly understood, although a role in cell adhesion has been demonstrated. To characterize the function of CD34 antigen on human HSCs, we examined, by both inhibition and overexpression, the role of CD34 in the regulation of HSC lineage differentiation. Our results demonstrate that CD34 silencing enhances HSC granulocyte and megakaryocyte differentiation and reduces erythroid maturation. In agreement with these results, the gene expression profile of these cells reveals the upregulation of genes involved in granulocyte and megakaryocyte differentiation and the downregulation of erythroid genes. Consistently, retroviral-mediated CD34 overexpression leads to a remarkable increase in erythroid progenitors and a dramatic decrease in granulocyte progenitors, as evaluated by clonogenic assay. Together, these data indicate that the CD34 molecule promotes the differentiation of CD34+ hematopoietic progenitors toward the erythroid lineage, which is achieved, at least in part, at the expense of granulocyte and megakaryocyte lineages.
authors.affiliation: Department of Biomedical Sciences, Biological Chemistry Section, University of Modena and Reggio Emilia, Via Campi 287, 41100 Modena, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Salati
authors.forename: Roberta
authors.initials: R
authors.lastname: Zini
authors.forename: Elisa
authors.initials: E
authors.lastname: Bianchi
authors.forename: Anna
authors.initials: A
authors.lastname: Testa
authors.forename: Fulvio
authors.initials: F
authors.lastname: Mavilio
authors.forename: Rossella
authors.initials: R
authors.lastname: Manfredini
authors.forename: Sergio
authors.initials: S
authors.lastname: Ferrari
mesh_terms: D018952:Antigens, CD34 / Q000235:genetics / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology*; D002478:Cells, Cultured; D002999:Clone Cells; D020869:Gene Expression Profiling; D020868:Gene Silencing / Q000502:physiology; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D023461:Myeloid Progenitor Cells / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D020411:Oligonucleotide Array Sequence Analysis
chemical_list: D018952:Antigens, CD34