title: Phospholipase D mediates matrix metalloproteinase-9 secretion in phorbol ester-stimulated human fibrosarcoma cells.
abstract: Phospholipase D (PLD) has been implicated in vesicle trafficking in the Golgi and hence secretion. In this study, we show that the secretion of matrix metalloproteinase-9 (MMP-9) from HT 1080 human fibrosarcoma cells was stimulated by phorbol 12-myristate 13-acetate in a time- and dose-dependent manner that involved protein kinase C. The phorbol ester also increased PLD activity in the cells. Evidence that PLD was involved in the stimulation of MMP-9 secretion was provided by the observations that the secretion of MMP-9 was stimulated by the introduction of short-chain phosphatidic acid (PA) into the growth medium and that inhibition of PA production by 1-propanol inhibited secretion. Using a short-chain diacylglycerol we excluded the possibility that MMP-9 secretion was induced by diacylglycerol formed from PA by phosphatidic acid phosphatase. Furthermore, propranolol, an inhibitor of this enzyme, had no effect on secretion induced by either phorbol 12-myristate 13-acetate or PA. The data presented here indicate that activation of protein kinase C increases MMP-9 secretion in HT 1080 cells and implicate PLD and PA formation in the effect.
authors.affiliation: Howard Hughes Medical Institute and the Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0295, USA.
authors.forename: B T
authors.initials: BT
authors.lastname: Williger
authors.forename: W T
authors.initials: WT
authors.lastname: Ho
authors.forename: J H
authors.initials: JH
authors.lastname: Exton
mesh_terms: D017364:Collagenases / Q000378:metabolism*; D004789:Enzyme Activation; D005354:Fibrosarcoma / Q000201:enzymology* / Q000473:pathology; D006056:Golgi Apparatus / Q000201:enzymology; D006801:Humans; D020780:Matrix Metalloproteinase 9; D010711:Phosphatidate Phosphatase / Q000378:metabolism; D010712:Phosphatidic Acids / Q000494:pharmacology; D010739:Phospholipase D / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D010712:Phosphatidic Acids; C084527:dioctanoylphosphatidic acid; D011493:Protein Kinase C; D010711:Phosphatidate Phosphatase; D010739:Phospholipase D; D017364:Collagenases; D020780:Matrix Metalloproteinase 9; D013755:Tetradecanoylphorbol Acetate