MC3T3-G2/PA6 preadipocytes support in vitro proliferation of hemopoietic stem cells through a mechanism different from that of interleukin 3.
Both MC3T3-G2/PA6 preadipocytes and interleukin 3 (IL 3) can support in vitro proliferation of mouse hemopoietic stem cells (CFU-S). We examined whether MC3T3-G2/PA6 cells produce IL 3 and whether a common mechanism might underlie the action of both of these agents. We used cultured mast cells, DA-1 cells, and FDC-P2 cells as the targets of IL 3 and conditioned medium (CM) of WEHI-3 cells as a source of IL 3. MC3T3-G2/PA6 CM did not support the growth of the above cells. IL 3 mRNA was not detected in the preadipocytes. Since CM obtained from the cocultures of bone marrow cells and MC3T3-G2/PA6 cells did not have a significant effect on the growth of the IL 3-dependent cells, none of the bone marrow cells seem to produce IL 3 under the influence of the preadipocytes. When the factor-dependent cells were cocultured with MC3T3-G2/PA6 cells, the former did not survive, whereas mast cells and DA-1 cells intimately associated with the preadipocytes. Even when bone marrow cells, mast cells, and MC3T3-G2/PA6 cells were cocultured, the number of CFU-S increased, but not that of mast cells. These results seem to exclude the possibility of the action of IL 3 in the microenvironment provided by MC3T3-G2/PA6 preadipocytes.
D000273:Adipose Tissue / Q000166:cytology / Q000502:physiology*; D000818:Animals; D001696:Biomechanical Phenomena; D001854:Bone Marrow Cells; D002455:Cell Division; D002460:Cell Line; D002470:Cell Survival; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D007377:Interleukin-3 / Q000235:genetics / Q000502:physiology*; D008407:Mast Cells / Q000166:cytology; D051379:Mice; D008815:Mice, Inbred Strains; D014158:Transcription, Genetic
D007377:Interleukin-3