TY - JOUR
T1 - The cebpa +37-kb enhancer directs transgene expression to myeloid progenitors and to long-term hematopoietic stem cells
AU - Guo, Hong
AU - Ma, Ou
AU - Friedman, Alan D.
PY - 2014/9
Y1 - 2014/9
N2 - C/EBPα is expressed preferentially in myeloid compared with lymphoid or erythroid cells and directs myeloid lineage specification. C/EBPα is also expressed at lower levels in HSCs and in several nonhematopoietic tissues. The Cebpa gene has a conserved, 450-bp segment at +37 kb that harbors enhancer-specific epigenetic marks and is activate in a myeloid cell line. Herein, we characterize transgenic C57BL/6 mice, in which the Cebpa enhancer and 845-bp promoter regulate a hCD4 reporter. FACS analysis, in vitro colony assays, and in vivo competitive and secondary transplantation revealed that myeloid but not MEPs or lymphoid progenitors and also functional LT-HSCs are found almost exclusively in the Cebpa-hCD4+ compared with hCD4- marrow population. hCD4+ CMP yielded predominantly myeloid, whereas hCD4 CMP- generated mainly Meg/E colonies. Providing insight into control of CMP maturation, Cebpa and Pu.1 RNAs were preferentially expressed in hCD4+ CMP, Scl, Gata2, Gata1, Klf1, Ets1, and Fli1 predominated in hCD4- CMP, and Runx1, Myb, HoxA9, and Erg levels were similar in both. Cebpa-hCD4 transgene expression was lacking in multiple nonhematopoietic tissues. In summary, the +37-kb Cebpa enhancer and promoter are sufficient for marrow myeloid progenitor and LT-HSC-specific expression.
AB - C/EBPα is expressed preferentially in myeloid compared with lymphoid or erythroid cells and directs myeloid lineage specification. C/EBPα is also expressed at lower levels in HSCs and in several nonhematopoietic tissues. The Cebpa gene has a conserved, 450-bp segment at +37 kb that harbors enhancer-specific epigenetic marks and is activate in a myeloid cell line. Herein, we characterize transgenic C57BL/6 mice, in which the Cebpa enhancer and 845-bp promoter regulate a hCD4 reporter. FACS analysis, in vitro colony assays, and in vivo competitive and secondary transplantation revealed that myeloid but not MEPs or lymphoid progenitors and also functional LT-HSCs are found almost exclusively in the Cebpa-hCD4+ compared with hCD4- marrow population. hCD4+ CMP yielded predominantly myeloid, whereas hCD4 CMP- generated mainly Meg/E colonies. Providing insight into control of CMP maturation, Cebpa and Pu.1 RNAs were preferentially expressed in hCD4+ CMP, Scl, Gata2, Gata1, Klf1, Ets1, and Fli1 predominated in hCD4- CMP, and Runx1, Myb, HoxA9, and Erg levels were similar in both. Cebpa-hCD4 transgene expression was lacking in multiple nonhematopoietic tissues. In summary, the +37-kb Cebpa enhancer and promoter are sufficient for marrow myeloid progenitor and LT-HSC-specific expression.
KW - Differentiation
KW - Hematopoiesis
KW - Myelopoiesis
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U2 - 10.1189/jlb.2AB0314-145R
DO - 10.1189/jlb.2AB0314-145R
M3 - Article
C2 - 24868087
AN - SCOPUS:84907331145
SN - 0741-5400
VL - 96
SP - 419
EP - 426
JO - Journal of Leukocyte Biology
JF - Journal of Leukocyte Biology
IS - 3
ER -