Physical Separation of Hemopoietic Stem Cells Differ-
نویسنده
چکیده
Two key properties of hemopoietic stem cells are their capacity for selfrenewal and their capacity for differentiation. The stem ceils in mouse hemopoietic tissues that may be detected by their ability to form macroscopic splenic colonies possess both these properties, but express them to widely varying degrees. For example, colonies derived from single stem cells may differ greatly in their content of differentiated cells (1-4). Individual colonies are also very heterogenous in their content of new stem cells (5). The basis for these differences in the composition of individual colonies has not been determined, but it has been suggested that self-renewal and differentiation occurring at random during colony growth might account for the observed variation. Alternatively, influences from the local environments of individual colonies might affect their development (4). Both of these models are based on the assumption that the stem cells form a homogeneous population in respect to their intrinsic potentialities for differentiation and seE-renewal. Indirect evidence has indicated that this may not be the case (6), and the possibility must be considered that the colonies derived from individual stem cells differ in composition because of intrinsic differences in the stem cells themselves. We have tested this possibility directly by utilizing a physical technique of cell separation, velocity sedimentation, to fractionate populations of hemopoietic stem cells into subpopulations possessing different sedimentation rates. Tests were made of the capacity for self-renewal of the stem cells present in the different fractions. Stem cells from different fractions were found to renew themselves to different degrees, providing strong evidence that stochastic processes and environmental factors are not the sole sources of heterogeneity in the composition of splenic colonies.
منابع مشابه
Separation of erythropoietin-sensitive cells from hemopoietic spleen colony-forming stem cells of mouse fetal liver by unit gravity sedimentation.
متن کامل
Isolation of murine fetal hemopoietic progenitor cells and selective fractionation of various erythroid precursors.
Hemopoietic progenitor cells (colony- and cluster-forming cells in semisolid agar) were purified from light density CBA murine fetal liver cells using fluorescein-conjugated pokeweed mitogen (PWM) and a rhodamine-conjugated antineutrophil serum sandwich (alpha N) and three-parameter fluorescence-activated cell sorting. All clonable progenitor cells were highly enriched (36-50-fold) in PWM-posit...
متن کاملTRANSFORMING GROWTH FACTOR β2 UP-REGULATES GM-CSF GENE IN HUMAN BLADDER CARCINOMA CELL LINE HTB 5637
Transforming growth factor betas are multifunctional polypeptides in the cytokine superfamily. They have a growth inhibitory role on hemopoietic progenitor cells in semisolid colony assay as well as in long-term bone-marrow culture. TGF - β2 represses stromal cells, stem cell factor gene transcription, and decreases the stability of c-kit transcripts in hemopoietic cells. TGF-β also modulat...
متن کاملEvaluation and Comparison of the Expression Levels of the ZBTB16 (Plzf) and ZFP Genes and Alkaline Phosphatase in Three Cell Populations: Mouse Spermatogonial Stem Cells, Embryonic Stem-Like Cells (Es-Like), And Embryonic Stem Cells
Introduction: One of the vital enzymes during spermatogenesis, which is one of the pluripotency factors of stem cells and contributes to maintaining their pluripotency is alkaline phosphatase. ZBTB16 and ZFP proteins are critical elements in stem cells which are expressed in pluripotent stem cells and maintain their pluripotency due to their role in messaging pathways. Material & Methods: The ...
متن کاملResponse of U n p r i m e d CBA Mice to 4 - Hydroxy - 3 - Iodo - 5 -
Cells of the immune system are heterogeneous by function, origin, and physical properties and there is increasing interest in isolation and characterization of the various lymphocyte subsets. Previous studies in this laboratory have made use of a battery of physical separation methods (cell electrophoresis, adherence column fractionation, sedimentation velocity separation, and buoyant density s...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2003