Synthesis of Fetal and Adult Hemoglobins in Culture by Human Umbilical Cord Blood Erythropoietic Precursors

Kidoguchi, Kinichi; Ogawa, Makio; Karam, J.D.; Wilson, Jeffrey M.; Fitch, Margaret S.

doi:10.3109/03630267809005352

Cited by 23 publications

(18 citation statements)

References 17 publications

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“…Whether or not bone marrow BFU-E in pregnant women are different in their capability to produce HbF in vitro compared to nonpregnant subjects has not been investigated. In other conditions in which the HbF in blood is increased, such as sickle cell anemia, both peripheral blood and bone marrow BFU-E produce significantly increased amounts of HbF in vitro (7,8,27).…”

Section: Methodsmentioning

confidence: 99%

“…The more ma- ture erythroid progenitor cells, colony-forming units that respond to erythropoietin (CFU-E), are present in bone marrow, but not in normal adult peripheral blood (4,5,21). Operationally, CFU-E from adult individuals can be distinguished from BFU-E by the much lower amount of erythropoietin required for growth in vitro, the shorter time necessary for colony formation, the much smaller size and compact appearance of the colonies, and their inability to synthesize HbF in vitro (7,8,22). In the present study, no CFU-E-derived colonies could be identified with confidence in cultures of peripheral blood mononuclear cells from pregnant women.…”

Section: Methodsmentioning

confidence: 99%

“…DISCUSSION Immature erythroid stem cells, BFU-E, are present in peripheral blood of normal adults (4,5) and pregnant women. These precursor cells can be induced by erythropoietin to proliferate and differentiate into large erythroid colonies capable of synthesizing a considerable amount of HbF (6)(7)(8). The more ma- ture erythroid progenitor cells, colony-forming units that respond to erythropoietin (CFU-E), are present in bone marrow, but not in normal adult peripheral blood (4,5,21).…”

Section: Methodsmentioning

confidence: 99%

“…These erythroblasts, derived from normal adult individuals, synthesize a substantial amount of fetal hemoglobin (6)(7)(8). Because HbF is increased in maternal peripheral blood during pregnancy (9)(10)(11), the present investigation was undertaken to determine if peripheral blood BFU-E in pregnant women have an increased capacity for HbF production in culture and to study the pattern of HbF synthesis during erythroid cell maturation in vitro.…”

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confidence: 99%

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Proportion of fetal hemoglobin synthesis decreases during erythroid cell maturation.

Chui¹,

Wong²,

Enkin³

et al. 1980

Proc. Natl. Acad. Sci. U.S.A.

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Peripheral blood mononuclear cells from pregnant and postpartum women were cultured in vitro with erythropoietin. Burst-forming unit (BFU-E)derived erythroid colonies composed of immature erythroblasts with low hemoglobin contents were observed by day 8 of culture. By day 12 of culture, numerous BFU-E-derived erythroid colonies with high hemoglobin contents were present. The Y/(y + f) globin synthetic ratio was approximately 12% in the early cultures and 6% in the late cultures, indicating that the proportion of fetal hemoglobin synthesis decreases during erythroid cell maturation. These studies also reveal that the capacity for fetal hemoglobin production by peripheral blood BFU-E in vitro is not altered during pregnancy.The major hemoglobin in humans during intrauterine life is fetal hemoglobin, a2Y2. Adult hemoglobin, a232, is first detected at around the 10th week of gestation and accounts for approximately 10% of all hemoglobins present until about the 30th week of gestation, when increasing amounts of adult hemoglobin are produced (1). By the time the infant is 6 months old, most of the hemoglobin present is adult hemoglobin (2). The mechanisms for the switching of hemoglobins during fetal development are presently not clear (3). These orderly ontogenetic changes provide an excellent model for studying gene regulation and expression. In addition, elucidation of the mechanisms for hemoglobin switching can provide a potentially useful approach to the therapy of patients with genetic disorders involving the j globin chain.Immature erythroid stem cells, burst-forming units that respond to erythropoietin (BFU-E), are present in adult human peripheral blood and can proliferate and differentiate into large colonies of erythroblasts in vitro (4, 5). These erythroblasts, derived from normal adult individuals, synthesize a substantial amount of fetal hemoglobin (6-8). Because HbF is increased in maternal peripheral blood during pregnancy (9-11), the present investigation was undertaken to determine if peripheral blood BFU-E in pregnant women have an increased capacity for HbF production in culture and to study the pattern of HbF synthesis during erythroid cell maturation in vitro. Evidence is presented that the capacity for HbF production by peripheral blood BFU-E in vitro is not altered during pregnancy. These studies also reveal that the proportion of HbF synthesis decreases during erythroid cell maturation. A preliminary report of these studies has been published elsewhere (12). METHODSSubjects. Forty-four pregnant and postpartum (3-7 months) women were studied. All women were healthy and had no known diseases or complications. Appropriate consent was obtained. [50][51][52][53][54][55][56][57][58][59][60] Ci/mmol; 1 Ci = 3.7 X 1010 becquerels), obtained from New England Nuclear, was added to each plasma clot on either day 6 or day 7, and either day 11 or day 12 of culture. Twenty-four hours later, 10 plasma clots thus labeled were pooled and washed twice with phosphate-buffered saline. Three milligrams o...

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Proportion of fetal hemoglobin synthesis decreases during erythroid cell maturation.

Chui¹,

Wong²,

Enkin³

et al. 1980

Proc. Natl. Acad. Sci. U.S.A.

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“…F cells contain both Hb A and Hb F, and they are derived from the same pluripotent stem-cell progenitors as the erythrocytes that fail to express Hb F (3)(4)(5). When erythroid progenitors [erythroid burst-forming unit(s); BFUe(s)] from adult persons are used for culture, reactivation of Hb F synthesis appears in the clones (6)(7)(8)(9). Hence, cultures of BFUes provide a tool for investigating the cellular mechanisms controlling the expression of Hb F in adult cells.…”

mentioning

confidence: 99%

Stochastic expression of fetal hemoglobin in adult erythroid cells.

Stamatoyannopoulos¹,

Kurnit²,

Papayannopoulou³

1981

Proc. Natl. Acad. Sci. U.S.A.

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The expression of fetal hemoglobin, Hb F, in the adult cells is cellularly restricted both in vivo and in culture. Because, in cultures of erythroid progenitors, subclones that express or fail to express Hb F are derived from the same erythroid stem cell, a mechanism must exist whereby Hb F expression segregates in the progeny of erythroid progenitors during their differentiation. We present mathematical analyses of experimental data which suggest that expression of Hb F in human adult erythroid cells occurs on a stochastic basis. We quantified Hb F expression among the subclones of erythroid bursts (clones) in vitro by labeling subclones with fluorescent anti-Hb F antibodies. The observed data were compared with predictions from a stochastic model with the assumption that the expression of Hb F in a subclone occurs with a probability P equal to the frequency of Hb F-expressing subclones in an experiment. There was good fit between the observed and predicted data with respect to: (i) the relative frequencies of monomorphic F+, monomorphic F-, and bimorphic F+/F- bursts, respectively; (ii) the size distributions among F+, F- and F+/F- bursts; and (iii) the proportions of subclones expressing Hb F within bimorphic F+/F- bursts. Given the hypothesis that erythroid progenitors which have an active Hb F program are less differentiated than cells which do not proceed to express Hb F, the stochastic event indicated by our analyses may be the probability that adult erythroid progenitor cells undergo terminal differentiation at an earlier stage than usual.

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Fetal to adult hemoglobin switch in cultures of early erythroid precursors from human fetuses and neonates

et al. 1979

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Erythroid burst colonies derived from the cord blood of nine neonates and from the blood and liver of three fetuses aborted after 20 weeks of gestation were grown in plasma clot culture. Their quantitative study revealed a higher proportion of burst-forming units (BFU-Es) in cord blood than in cord blood of normal adults. In addition, colony-forming units (CFU-Es) were present in cord blood but absent from adult blood. Study of haemoglobin synthesis in 14-day cultures of cord blood BFU-Es showed a significantly higher degree of Hb A synthesis than was found in reticulocytes from fresh cord blood; this proportion was, however, similar to that expected in vivo about three weeks after birth. These data suggest that the hemoglobin switch is already programmed in most of the early erythroid precursors present in cord blood or full-term neonates and indicate that the differentiation time is probably of the same order of magnitude in vivo and in vitro. The proportion of Hb A and F synthesis in erythroid bursts was not influenced by the concentration of erythropoietin in the range studied--ie, from 0.5 to 12 international units. Low but identical proportions of Hb A synthesis were found both in erythroid cells from liver after two hours of incubation with [3H]-leucine, and in 14-day liver bursts from fetuses aborted at 20 weeks of gestation.

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Synthesis of Fetal and Adult Hemoglobins in Culture by Human Umbilical Cord Blood Erythropoietic Precursors

Cited by 23 publications

References 17 publications

Proportion of fetal hemoglobin synthesis decreases during erythroid cell maturation.

Proportion of fetal hemoglobin synthesis decreases during erythroid cell maturation.

Stochastic expression of fetal hemoglobin in adult erythroid cells.

Fetal to adult hemoglobin switch in cultures of early erythroid precursors from human fetuses and neonates

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