Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2001-3-12
pubmed:abstractText
CCAAT/enhancer binding protein epsilon (C/EBPepsilon) is essential for terminal granulocytic differentiation. Its expression begins at the transition between the proliferative and non-proliferative compartments of myelopoiesis. We studied the effect of targeted disruption of the C/EBPepsilon gene on murine myeloid proliferation and apoptosis. Bone marrow cellularity of C/EBPepsilon -/- and wild-type mice was 95% and 65%, respectively. The C/EBPepsilon -/- mice had an expansion in the number of their CFU-GM/femur. The number of myeloid committed progenitor cells in the peripheral blood and the spleen of these mice was also increased. Bromodeoxyuridine (BrDU) pulse labeling studies demonstrated that the fraction of actively proliferating cells was two-fold higher in the bone marrow of C/EBPepsilon -/- mice. However, the number of myeloid colonies arising from purified Sca-1+/lin- early hematopoietic progenitor cells and from bone marrow mononuclear cells grown in different cytokine combinations was not significantly different between wild-type and knock-out mice. Also, long-term marrow growth, and CFU were not different between the wild-type and C/EBPepsilon -/- mice. The sensitivity to induction of apoptosis in the committed progenitor cell compartment after either withdrawal of growth factor or brief exposure to etoposide was normal. However, Gr-1 antigen-positive C/EBPepsilon -/- granulocytic cells showed an increased rate of apoptosis in comparison to their wild-type counterparts. In summary, the myeloid compartment appears to be expanded in mice lacking C/EBPepsilon. However, this is not the consequence of an intrinsic myeloproliferation but due to an indirect, possibly cytokine-mediated stimulation of myelopoiesis in vivo. C/EBPepsilon may have a role in the inhibition of apoptosis in maturing granulocytic cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0887-6924
pubmed:author
pubmed:issnType
Print
pubmed:volume
15
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
103-11
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
C/EBPepsilon -/- mice: increased rate of myeloid proliferation and apoptosis.
pubmed:affiliation
Division of Hematology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't