title: Tcf7 is an important regulator of the switch of self-renewal and differentiation in a multipotential hematopoietic cell line.
abstract: A critical problem in biology is understanding how cells choose between self-renewal and differentiation. To generate a comprehensive view of the mechanisms controlling early hematopoietic precursor self-renewal and differentiation, we used systems-based approaches and murine EML multipotential hematopoietic precursor cells as a primary model. EML cells give rise to a mixture of self-renewing Lin-SCA+CD34+ cells and partially differentiated non-renewing Lin-SCA-CD34- cells in a cell autonomous fashion. We identified and validated the HMG box protein TCF7 as a regulator in this self-renewal/differentiation switch that operates in the absence of autocrine Wnt signaling. We found that Tcf7 is the most down-regulated transcription factor when CD34+ cells switch into CD34- cells, using RNA-Seq. We subsequently identified the target genes bound by TCF7, using ChIP-Seq. We show that TCF7 and RUNX1 (AML1) bind to each other's promoter regions and that TCF7 is necessary for the production of the short isoforms, but not the long isoforms of RUNX1, suggesting that TCF7 and the short isoforms of RUNX1 function coordinately in regulation. Tcf7 knock-down experiments and Gene Set Enrichment Analyses suggest that TCF7 plays a dual role in promoting the expression of genes characteristic of self-renewing CD34+ cells while repressing genes activated in partially differentiated CD34- state. Finally a network of up-regulated transcription factors of CD34+ cells was constructed. Factors that control hematopoietic stem cell (HSC) establishment and development, cell growth, and multipotency were identified. These studies in EML cells demonstrate fundamental cell-intrinsic properties of the switch between self-renewal and differentiation, and yield valuable insights for manipulating HSCs and other differentiating systems.
authors.affiliation: Department of Genetics, Stanford University School of Medicine, Stanford, California, United States of America. Jiaqian2009.wu@gmail.com
authors.forename: Jia Qian
authors.initials: JQ
authors.lastname: Wu
authors.forename: Montrell
authors.initials: M
authors.lastname: Seay
authors.forename: Vincent P
authors.initials: VP
authors.lastname: Schulz
authors.forename: Manoj
authors.initials: M
authors.lastname: Hariharan
authors.forename: David
authors.initials: D
authors.lastname: Tuck
authors.forename: Jin
authors.initials: J
authors.lastname: Lian
authors.forename: Jiang
authors.initials: J
authors.lastname: Du
authors.forename: Minyi
authors.initials: M
authors.lastname: Shi
authors.forename: Zhijia
authors.initials: Z
authors.lastname: Ye
authors.forename: Mark
authors.initials: M
authors.lastname: Gerstein
authors.forename: Michael P
authors.initials: MP
authors.lastname: Snyder
authors.forename: Sherman
authors.initials: S
authors.lastname: Weissman
mesh_terms: D000818:Animals; D018952:Antigens, CD34 / Q000378:metabolism; D002454:Cell Differentiation; D002460:Cell Line; D049109:Cell Proliferation; D050676:Core Binding Factor Alpha 2 Subunit / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D055785:Gene Knockdown Techniques; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000378:metabolism*; D051538:Hepatocyte Nuclear Factor 1-alpha; D006801:Humans; D051379:Mice; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D034741:RNA, Small Interfering; D017423:Sequence Analysis, RNA; D051822:T Cell Transcription Factor 1 / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism*; D014157:Transcription Factors / Q000145:classification / Q000378:metabolism
chemical_list: D018952:Antigens, CD34; D050676:Core Binding Factor Alpha 2 Subunit; D051538:Hepatocyte Nuclear Factor 1-alpha; C496488:Hnf1a protein, mouse; D034741:RNA, Small Interfering; C493726:Runx1 protein, mouse; D051822:T Cell Transcription Factor 1; D014157:Transcription Factors