[Colony formation of mouse primitive hemopoietic progenitors with interleukin-6 and phorbol ester, and their signal transduction].
Colony formation of mouse primitive hemopoietic progenitors with interleukin-6 (IL-6) and 12-O-tetradecanoyl-phorbol-13-acetate (TPA), and their signal transduction were studied. Although IL-6 or TPA alone could not form colonies, their combination gave rise to significant number of colonies from Day-2 post 5-FU bone marrow cells. When colony numbers were compared with those supported by IL-3, IL-6+TPA gave rise to 86 + 47% of colonies formed with IL-3. Time course of colony formation with IL-6+TPA run parallel with that of IL-3. These colonies included not only granulocyte/macrophage (GM) colonies, but also granulocyte/erythrocyte/macrophage/megakaryocyte (GEMM) colonies and blast cell colonies. Delayed addition of IL-6 or TPA decreased colony numbers, suggesting that both IL-6 and TPA were needed from the start of cultures for maximal colony formation. When cultures were started with TPA, and IL-6 was added on Day 2 of culture or later, few colonies developed. These data suggested that IL-6 might be essential to the survival of the progenitors in culture. Chronic exposure of progenitors to TPA prior to the culture with IL-6+TPA suppressed colony formation. Addition of calphostin C, a specific protein kinase C (PKC) inhibitor or genistein and herbimycin A, specific tyrosine kinase (TK) inhibitors to the culture also decreased colony numbers formed with IL-6 and TPA. To clarify which effects of IL-6 or TPA on colony formation were blocked by the inhibitors, the inhibitors were added to preincubation of progenitors with IL-6. Both the PKC inhibitor and TK inhibitors blocked the increase of colonies resulted from a pre-incubation with IL-6. Although delayed addition of TPA enhanced IL-6-dependent colony formation, delayed addition of TPA with either the PKC inhibitor or TK inhibitors canceled the increase of colonies. These data suggested that both signals of IL-6 and TPA might be transduced via activation of PKC and TK, but further studies are needed to confirm that.
Soga
R
R
Third Department of Internal Medicine, Hokkaido University School of Medicine, Sapporo, Japan.
D000818:Animals; D001854:Bone Marrow Cells; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D015536:Down-Regulation; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D015850:Interleukin-6 / Q000494:pharmacology* / Q000502:physiology; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D010703:Phorbol Esters / Q000494:pharmacology*; D011493:Protein Kinase C / Q000378:metabolism; D015398:Signal Transduction
D015850:Interleukin-6; D010703:Phorbol Esters; D011493:Protein Kinase C