1: Exp Hematol. 2002 Aug;30(8):887-95. 

GATA transcription in a small rhodamine 123(low)CD34(+) subpopulation of a
peripheral blood-derived CD34(-)CD105(+) mesenchymal cell line.

Conrad C, Gottgens B, Kinston S, Ellwart J, Huss R.

Institute of Pathology, University of Munich, Germany.

OBJECTIVE: Based on previous animal experiments that suggest the plasticity of
peripheral blood-derived, CD34(-) stem cell lines, the aim of this study was to
isolate CD34(-) stem cell lines from human peripheral blood cells and obtain
evidence of their multipotency and plasticity. MATERIALS AND METHODS: Adherent
growing cells were isolated from peripheral blood mononuclear cells from a
healthy volunteer donor and different cell clones were established after SV40
large-T-antigen-mediated immortalization. The immunophenotype of the cell lines
was investigated by flow cytometry. One particular cell clone, V54/2, was
stained with rhodamine 123, and the Rh123(low) and Rh123(high) subpopulations
were sorted for a reverse transcriptase polymerase chain reaction gene
expression survey and distinct differences in morphology and biologic behavior.
RESULTS: The peripheral blood-derived and fibroblast-like cell line V54/2
expressed high levels of CD10 and CD105 and showed only a very low level
expression of CD34 (<1.0%) and CD117 (c-kit). Among the entire CD34(-)CD105(+)
cell population that transcribed factors such as Myb, Tie-1, and VEGF, there was
a small Rh123(low)CD34(+) subpopulation that transcribed significant levels of
several members of the GATA family of transcription factors. The morphology of
the Rh123(low)CD34(+) (also expressing the P-glycoprotein) was different
compared to the Rh123(high)CD34(-) population. Mesenchymal differentiation into
glial fibrillary acidic protein (GFAP)(+) glial cells could be shown from the
entire CD34(-)CD105(+) cell population. CONCLUSIONS: The findings provide
evidence that it is possible to isolate CD34(-)CD105(+) mesenchymal stem cell
lines from human peripheral blood cells that contain a small subpopulation of
CD34(+) and GATA-transcribing cells. Those cells are potential hematopoietic
progenitors and can be recruited from the CD34(-) stem cell pool. The plasticity
of stem cells seems to require essential molecular tools, such as a panel of
transcription factors, to respond to the environmental demand within a biologic
system.

PMID: 12160840 [PubMed - indexed for MEDLINE]


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2: Dev Biol. 2002 Jun 1;246(1):103-21. 

Definition of regulatory network elements for T cell development by perturbation
analysis with PU.1 and GATA-3.

Anderson MK, Hernandez-Hoyos G, Dionne CJ, Arias AM, Chen D, Rothenberg EV.

Division of Biology, California Institute of Technology, Pasadena 91125, USA.

PU.1 and GATA-3 are transcription factors that are required for development of T
cell progenitors from the earliest stages. Neither one is a simple positive
regulator for T lineage specification, however. When expressed at elevated
levels at early stages of T cell development, each of these transcription
factors blocks T cell development within a different, characteristic time
window, with GATA-3 overexpression initially inhibiting at an earlier stage than
PU.1. These perturbations are each associated with a distinct spectrum of
changes in the regulation of genes needed for T cell development. Both
transcription factors can interfere with expression of the Rag-1 and Rag-2
recombinases, while GATA-3 notably blocks PU.1 and IL-7Ralpha expression, and
PU.1 reduces expression of HES-1 and c-Myb. A first-draft assembly of the
regulatory targets of these two factors is presented as a provisional gene
network. The target genes identified here provide insight into the basis of the
effects of GATA-3 or PU.1 overexpression and into the regulatory changes that
distinguish the developmental time windows for these effects. (c) 2002 Elsevier
Science (USA).

PMID: 12027437 [PubMed - indexed for MEDLINE]


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3: Genes Dev. 1994 May 15;8(10):1184-97. 

Novel insights into erythroid development revealed through in vitro
differentiation of GATA-1 embryonic stem cells.

Weiss MJ, Keller G, Orkin SH.

Division of Hematology-Oncology, Children's Hospital, Dana Farber Cancer
Institute, Boston, Massachusetts.

Mouse embryonic stem (ES) cells lacking the transcription factor GATA-1 do not
produce mature red blood cells either in vivo or in vitro. To define the
consequences of GATA-1 loss more precisely, we used an in vitro ES cell
differentiation assay that permits enumeration of primitive (EryP) and
definitive (EryD) erythroid precursors and recovery of pure erythroid colonies.
In contrast to normal ES cells, GATA-1- ES cells fail to generate EryP
precursors. EryD precursors, however, are normal in number but undergo
developmental arrest and death at the proerythroblast stage. Contrary to initial
expectations, arrested GATA-1(-)-definitive proerythroblasts express GATA target
genes at normal levels. Transcripts of the related factor GATA-2 are remarkably
elevated in GATA-1- proerythroblasts. These findings imply substantial
interchangeability of GATA factors in vivo and suggest that GATA-1 normally
serves to repress GATA-2 during erythropoiesis. The approach used here is a
paradigm for the phenotypic analysis of targeted mutations affecting
hematopoietic development.

PMID: 7926723 [PubMed - indexed for MEDLINE]


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