SEARCH:   Advanced

Blood, 15 May 2005, Vol. 105, No. 10, pp. 3888-3892. Prepublished online as a Blood First Edition Paper on February 8, 2005; DOI 10.1182/blood-2004-08-3109. This Article Full Text Full Text (PDF) All Versions of this Article: 2004-08-3109v1 105/10/3888    most recent Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Rights and Permissions Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Kanaji, S. Articles by Kunicki, T. J. Search for Related Content PubMed PubMed Citation Articles by Kanaji, S. Articles by Kunicki, T. J. Related Collections Gene Expression Hematopoiesis Hemostasis, Thrombosis, and Vascular Biology Social Bookmarking                   What's this?  Previous Article  |  Table of Contents  |  Next Article  HEMOSTASIS, THROMBOSIS, AND VASCULAR BIOLOGY Thrombopoietin initiates demethylation-based transcription of GP6 during megakaryocyte differentiation Sachiko Kanaji, Taisuke Kanaji, Beatrice Jacquelin, Mei Chang, Diane J. Nugent, Norio Komatsu, Masaaki Moroi, Kenji Izuhara, and Thomas J. Kunicki From The Roon Research Center for Arteriosclerosis and Thrombosis, Division of Experimental Hemostasis and Thrombosis, Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA; the Children's Hospital of Orange County, Orange, CA; the Department of Hematology, University of Yamanashi, Tamaho, Yamanashi, Japan; the Division of Medical Biochemistry, Department of Biomolecular Sciences, Saga Medical School, Saga, Japan; and the Department of Protein Biochemistry, Institute of Life Science, Kurume University, Kurume, Fukuoka, Japan. Glycoprotein VI (GPVI) is an essential platelet receptor for collagens that is exclusively expressed in the megakaryocytic lineage. Transcription of the human gene GP6 is driven largely by GATA-binding protein 1 (GATA-1), specificity protein 1 (Sp1), and Friend leukemia integration 1 (Fli-1). In this report, we show that GPVI expression during megakaryocytic differentiation is dependent on cytosine-phosphate-guanosine (CpG) demethylation that can be initiated by thrombopoietin (TPO). Sodium bisulfite genomic sequencing established that a CpG-rich island within the GP6 promoter region is fully methylated at 10 CpG sites in GPVI-nonexpressive cell lines, such as UT-7/EPO and C8161, but completely unmethylated in GPVI-expressive cell lines, including UT-7/TPO and CHRF288-11. To further confirm the relationship between CpG demethylation and expression of GPVI in primary cells, we treated human cord blood cells with TPO. The GP6 promoter is highly methylated in cord blood mononuclear cells (progenitors) but not in CD41+-enriched cells obtained after TPO differentiation. Furthermore, when UT-7/EPO-Mpl cells, which stably express human C-myeloproliferative leukemia virus ligand (c-Mpl), were treated with TPO, demethylation of the GP6 promoter was induced. In every case, demethylation of the GP6 promoter correlated with an increase in mRNA level. Thus, megakaryocyte-specific expression of the GP6 gene is regulated, in part, by CpG demethylation, which can be directly initiated by TPO. CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

	Blood Online is supported in part by Genentech BioOncology and Biogen Idec
	Copyright © 2005 by American Society of Hematology         Online ISSN: 1528-0020