Apoptosis and hematopoiesis in murine fetal liver

摘要: The fetal mouse liver (FL) is an organ of intense, but transient, hematopoietic activity during mid-gestation, with erythropoiesis being predominant days 11 through 16. It therefore seemed reasonable to expect that cytokines, such as erythropoietin (epo), interleukin-3 (IL-3), and stem cell factor (SCF), may play important roles in maintaining a homeostatic balance apoptosis ontogeny. First, we determined the effects these growth factors on hematopoiesis by measuring colony formation hemoglobin synthesis cultured FLs. Secondly, protection from afforded using electrophoretic analysis DNA flow cytometry FL cells deprived culture epo, IL-3, SCF. Erythropoietin was necessary alone sufficient for colony-forming units-erythroid colonies, IL-3 required cofactor obtain maximal development burst-forming colonies. SCF caused little methylcellulose cultures FLs, when combined epo it had dramatic both number colonies their size. indices were fragmentation endogenous nuclease apoptotic cells. Liver without cytokines showed extensive degradation low molecular weight nucleosomal oligomers, which characteristic apoptosis. Protection directly corresponded level FLs different gestational age. far most critical cytokine sparing Analyses agarose gels no apparent effect reducing amount fragments, they more protective than provided alone. However, sensitive cytometric determination subdiploid amounts DNA, SCF, measurable less those epo. Thus, show normal, untransformed developing system not only require proliferation differentiation, have initial absolute requirement them