title: Increased levels of NOTCH1, NF-kappaB, and other interconnected transcription factors characterize primitive sets of hematopoietic stem cells.
abstract: As previously shown, higher levels of NOTCH1 and increased NF-kappaB signaling is a distinctive feature of the more primitive umbilical cord blood (UCB) CD34+ hematopoietic stem cells (HSCs), as compared to bone marrow (BM). Differences between BM and UCB cell composition also account for this finding. The CD133 marker defines a more primitive cell subset among CD34+ HSC with a proposed hemangioblast potential. To further evaluate the molecular basis related to the more primitive characteristics of UCB and CD133+ HSC, immunomagnetically purified human CD34+ and CD133+ cells from BM and UCB were used on gene expression microarrays studies. UCB CD34+ cells contained a significantly higher proportion of CD133+ cells than BM (70% and 40%, respectively). Cluster analysis showed that BM CD133+ cells grouped with the UCB cells (CD133+ and CD34+) rather than to BM CD34+ cells. Compared with CD34+ cells, CD133+ had a higher expression of many transcription factors (TFs). Promoter analysis on all these TF genes revealed a significantly higher frequency (than expected by chance) of NF-kappaB-binding sites (BS), including potentially novel NF-kappaB targets such as RUNX1, GATA3, and USF1. Selected transcripts of TF related to primitive hematopoiesis and self-renewal, such as RUNX1, GATA3, USF1, TAL1, HOXA9, HOXB4, NOTCH1, RELB, and NFKB2 were evaluated by real-time PCR and were all significantly positively correlated. Taken together, our data indicate the existence of an interconnected transcriptional network characterized by higher levels of NOTCH1, NF-kappaB, and other important TFs on more primitive HSC sets.
authors.affiliation: Department of Clinical Medicine of the Faculty of Medicine of Ribeirao Preto-USP, Center for Cell Therapy and Regional Blood Center, Araraquara, São Paulo, Brazil. rapane@gmail.com
authors.forename: Rodrigo Alexandre
authors.initials: RA
authors.lastname: Panepucci
authors.forename: Lucila Habib B
authors.initials: LH
authors.lastname: Oliveira
authors.forename: Dalila Luciola
authors.initials: DL
authors.lastname: Zanette
authors.forename: Rita de Cassia
authors.initials: Rde C
authors.lastname: Viu Carrara
authors.forename: Amélia Goes
authors.initials: AG
authors.lastname: Araujo
authors.forename: Maristela Delgado
authors.initials: MD
authors.lastname: Orellana
authors.forename: Patrícia Vianna
authors.initials: PV
authors.lastname: Bonini de Palma
authors.forename: Camila C B O
authors.initials: CC
authors.lastname: Menezes
authors.forename: Dimas Tadeu
authors.initials: DT
authors.lastname: Covas
authors.forename: Marco Antonio
authors.initials: MA
authors.lastname: Zago
mesh_terms: D000071916:AC133 Antigen; D015703:Antigens, CD / Q000032:analysis; D018952:Antigens, CD34 / Q000032:analysis; D019070:Cell Lineage / Q000235:genetics; D016000:Cluster Analysis; D005312:Fetal Blood / Q000166:cytology; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D006023:Glycoproteins / Q000032:analysis; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D016328:NF-kappa B / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D010455:Peptides / Q000032:analysis; D051881:Receptor, Notch1 / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D000071916:AC133 Antigen; D015703:Antigens, CD; D018952:Antigens, CD34; D006023:Glycoproteins; D016328:NF-kappa B; C497761:NOTCH1 protein, human; C000606023:PROM1 protein, human; D010455:Peptides; D051881:Receptor, Notch1; D014157:Transcription Factors