Stage-specific cell-cycling of hematopoietic progenitor cells.
We studied the growth of hematopoietic progenitors at different progressive stages of differentiation and focused especially on changes in cell-cycling. Hematopoietic progenitors from 5-fluorouracil (5-FU)-treated mice were separated into three groups on the basis of differentiation, Stages I, II, and III, and have studied their cell-cycling. Primary marrow cells collected from 5-FU-treated mice were categorized as Stage I progenitors. Stages II and III progenitors are early and late progenies of Stage I progenitors, respectively. The rate of growth of hematopoietic progenitors supported by interleukin-3 (IL-3) and steel factor (SF) was estimated by sequential analysis of colony formation and studying replating efficiency of individual colonies. The time required for hematopoietic progenitors to go through the cell-cycle shortened as their stage of differentiation progressed. Similar results were obtained with other growth factor combinations. The analysis of DNA content of cells suggests that shortening of cell-cycling is mainly due to a decrease in the time of G1 phase of the cell-cycle. Our results demonstrate that in early hematopoiesis, the cell-cycling of hematopoietic progenitors accelerates as they differentiate.
Mahmud
N
N
Second Department of Internal Medicine, Mie University School of Medicine, Japan.
Katayama
N
N
Ohishi
K
K
Itoh
R
R
Minami
N
N
Shiku
H
H
D000818:Animals; D001854:Bone Marrow Cells; D002453:Cell Cycle; D002454:Cell Differentiation; D002478:Cells, Cultured; D005472:Fluorouracil; D016193:G1 Phase; D006133:Growth Substances / Q000494:pharmacology; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects; D017370:Interleukin-11 / Q000494:pharmacology; D007377:Interleukin-3 / Q000494:pharmacology; D051379:Mice; D019089:Stem Cell Factor / Q000494:pharmacology
D006133:Growth Substances; D017370:Interleukin-11; D007377:Interleukin-3; D019089:Stem Cell Factor; D005472:Fluorouracil