title: Tumor necrosis factor type alpha stimulates human endothelial cells to produce granulocyte/macrophage colony-stimulating factor.
abstract: Tumor necrosis factor type alpha (TNF-alpha) is produced by monocytes and has been purified, sequenced, and cloned from the HL-60 cell line. Soluble products of monocytes stimulate endothelial cells to release multilineage hematopoietic colony-stimulating activity. To determine whether TNF-alpha could stimulate endothelial cells to produce these activities, we added recombinant human TNF-alpha to cultured human umbilical vein endothelial cells. Untreated endothelial cell conditioned medium and TNF-alpha-stimulated endothelial cell conditioned medium were tested for hematopoietic colony stimulating activity in colony-forming assays in methylcellulose. TNF-alpha stimulated growth factor production by endothelial cells. Fifth-passage human endothelial cells and multiply-passaged bovine aortic endothelial cells responded similarly to first-passage endothelial cells, indicating that the action of TNF-alpha on endothelial cells is direct and not due to contaminating lymphocytes or monocytes present in the first-passage cultures. To investigate the molecular basis for these findings, polyadenylylated RNA was prepared from the TNF-alpha-stimulated endothelial cells and probed for granulocyte-macrophage colony-stimulating factor and granulocyte colony-stimulating factor mRNA. Granulocyte-macrophage colony-stimulating factor, but not granulocyte colony-stimulating factor, message was detected. This finding suggests that at least some of the hematopoietic colony-stimulating activity released by the TNF-alpha-stimulated endothelial cells is granulocyte-macrophage colony-stimulating factor. These results demonstrate that a purified monocyte product can stimulate endothelial cells to produce the multilineage growth factor granulocyte-macrophage colony-stimulating factor and extend the role of this immunoregulatory protein to the regulation of hematopoiesis in vitro.
mesh_terms: D002478:Cells, Cultured; D003115:Colony-Stimulating Factors / Q000096:biosynthesis* / Q000235:genetics; D003513:Cycloheximide / Q000494:pharmacology; D004727:Endothelium / Q000502:physiology*; D005786:Gene Expression Regulation / Q000187:drug effects; D006023:Glycoproteins / Q000494:pharmacology*; D006410:Hematopoiesis / Q000187:drug effects; D006801:Humans; D008222:Lymphokines / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha
chemical_list: D003115:Colony-Stimulating Factors; D006023:Glycoproteins; D008222:Lymphokines; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D003513:Cycloheximide