CFU-E

CFU-Estands forColony Forming Unit-Erythroid.^[1]It arises fromCFU-GEMM(via BFU-E,^[2]which stands for "erythroid burst-forming units"^[3]) and gives rise toproerythroblasts.

Murine CFU-E assay[edit]

CFU-E is a stage of erythroid development between the BFU-E stage and the pro-erythroblast stage. CFU-E colony assay is designed to detect how many colony-forming-units of erythroid lineage there are in a hematopoietic tissue (bone marrow, spleen, or fetal liver), which may be reflective of the organism’s demand for oxygen delivery to the tissues or a hematopoietic disorder.

Early erythroid progenitors are found at a quite low frequency relative to later stages of erythroid differentiation, such as the pro-erythroblast and the basophilic erythroblast stages which can be detected by flowcytometry directly ex-vivo.^[4]Furthermore, unlike for the pro-erythroblast and later stages of erythroid development, no truly reliable and unique positive flow-cytometric markers exist, though it is possible to use negative exclusion markers to deplete a cell population of other precursors and differentiated cells by cell sorting, thus greatly enriching it for the CFU-E activity.^[5]CFU-E cells express Epo receptor, c-Kit (Stem cell factor receptor),transferrin receptor(CD71+), and are Ter119(glycophorin-A associated antigen)-negative. For the above reasons, the CFU-E assay, as inefficient and variable as it can often be, is still in use today.

Cells at the CFU-E stage express someerythropoietin receptor(EpoR), and thus can be induced to terminally differentiate in vitro in 2–3 days in the presence of onlyerythropoietin(Epo) (together with the basic contents of culture media: FBS, BSA in IMDM). Methylcellulose is a semisolid media additive that allows an investigator to stain (with diaminobenzidine reagent for hemoglobin) and then count individual colonies, each arising from a single plated progenitor that is at the CFU-E stage. By day 2 from the time of plating, each CFU-E colony will contain between 8 (minimum) and 64 hemoglobinized cells most of which are in their end-stage of erythroid differentiation. It is possible to see a small spectrum of hemoglobinization level and possibly cell size, indicating that some cells in the colony have achieved the end-stage faster than others.

Cell number in a colony is important because pro-erythroblast stage is also Epo-responsive (expresses Epo receptor), but the proliferative capacity of these cells is not as high, thus yielding a colony with fewer than 8 cells. Likewise, an earlier stage of erythroid differentiation may also yield colonies in Epo-only medium, but these colonies would likely be smaller and/or not hemoglobinized, since the stages before the CFU-E stage (MEP and BFU-E) require other factors (IL-3 etc) and more time for growth that will also delay the terminal differentiation and hemoglobinization.

References[edit]

^Miller, Cindy L.; Dykstra, Brad; Eaves, Connie J. (2008). "Characterization of Mouse Hematopoietic Stem and Progenitor Cells".Current Protocols in Immunology.80(1): 22B.2.1–22B.2.31.doi:10.1002/0471142735.im22b02s80.ISSN 1934-368X.PMID 18432636.
^Wu H, Liu X, Jaenisch R, Lodish HF (October 1995)."Generation of committed erythroid BFU-E and CFU-E progenitors does not require erythropoietin or the erythropoietin receptor".Cell.83(1): 59–67.doi:10.1016/0092-8674(95)90234-1.PMID 7553874.
^Marley SB, Lewis JL, Goldman JM, Gordon MY (June 1996). "Abnormal kinetics of colony formation by erythroid burst-forming units (BFU-E) in chronic myeloid leukaemia".Br. J. Haematol.93(4): 878–83.doi:10.1046/j.1365-2141.1996.d01-1738.x.PMID 8703820.
^Socolovsky, Merav; Nam, Hyung-song; Fleming, Mark D.; Haase, Volker H.; Brugnara, Carlo; Lodish, Harvey F. (2001-12-01)."Ineffective erythropoiesis in Stat5a−/−5b−/− mice due to decreased survival of early erythroblasts".Blood.98(12): 3261–3273.doi:10.1182/blood.V98.12.3261.ISSN 0006-4971.
^Terszowski, Grzegorz; Waskow, Claudia; Conradt, Peter; Lenze, Dido; Koenigsmann, Jessica; Carstanjen, Dirk; Horak, Ivan; Rodewald, Hans-Reimer (2005-03-01)."Prospective isolation and global gene expression analysis of the erythrocyte colony-forming unit (CFU-E)".Blood.105(5): 1937–1945.doi:10.1182/blood-2004-09-3459.ISSN 0006-4971.

External links[edit]

CFU-Eat the U.S. National Library of MedicineMedical Subject Headings(MeSH)

[1] Miller, Cindy L.; Dykstra, Brad; Eaves, Connie J. (2008). "Characterization of Mouse Hematopoietic Stem and Progenitor Cells".Current Protocols in Immunology.80(1): 22B.2.1–22B.2.31.doi:10.1002/0471142735.im22b02s80.ISSN 1934-368X.PMID 18432636.

[pmid7553874-2] Wu H, Liu X, Jaenisch R, Lodish HF (October 1995)."Generation of committed erythroid BFU-E and CFU-E progenitors does not require erythropoietin or the erythropoietin receptor".Cell.83(1): 59–67.doi:10.1016/0092-8674(95)90234-1.PMID 7553874.

[pmid8703820-3] Marley SB, Lewis JL, Goldman JM, Gordon MY (June 1996). "Abnormal kinetics of colony formation by erythroid burst-forming units (BFU-E) in chronic myeloid leukaemia".Br. J. Haematol.93(4): 878–83.doi:10.1046/j.1365-2141.1996.d01-1738.x.PMID 8703820.

[4] Socolovsky, Merav; Nam, Hyung-song; Fleming, Mark D.; Haase, Volker H.; Brugnara, Carlo; Lodish, Harvey F. (2001-12-01)."Ineffective erythropoiesis in Stat5a−/−5b−/− mice due to decreased survival of early erythroblasts".Blood.98(12): 3261–3273.doi:10.1182/blood.V98.12.3261.ISSN 0006-4971.

[5] Terszowski, Grzegorz; Waskow, Claudia; Conradt, Peter; Lenze, Dido; Koenigsmann, Jessica; Carstanjen, Dirk; Horak, Ivan; Rodewald, Hans-Reimer (2005-03-01)."Prospective isolation and global gene expression analysis of the erythrocyte colony-forming unit (CFU-E)".Blood.105(5): 1937–1945.doi:10.1182/blood-2004-09-3459.ISSN 0006-4971.

[1]

[2]

[3]

[4]

[5]