tailieunhanh - Báo cáo khoa học: Secretion of macrophage urokinase plasminogen activator is dependent on proteoglycans

The importance of proteoglycans for secretionof proteolytic enzymes was studied in the murine macrophage cell line J774. Untreated or 4b-phorbol 12-myristate 13-acetate (PMA)-stimulated macrophages were treated with hexyl-b-D-thioxyloside to interfere with the attachment of glycosaminoglycan chains to their respective protein cores. Activation of the J774 macrophages with PMA resulted in increased secretion of trypsin-like serine proteinase activity. | Eur. J. Biochem. 270 3971-3980 2003 FEBS 2003 doi Secretion of macrophage urokinase plasminogen activator is dependent on proteoglycans Gunnar Pejler1 Jan-Olof Winberg2 Tram T. Vuong3 Frida Henningsson1 Lars Uhlin-Hansen2 Koji Kimata4 and Svein O. Kolset5 1 Department of Veterinary Medical Chemistry Swedish University of Agricultural Sciences Uppsala Sweden department of Biochemistry Institute of Medical Biology University of Troms0 Norway 3Department of Biochemistry University of Oslo Norway 4Institute for Molecular Science of Medicine Aichi Medical University Japan 5Institute for Nutrition Research University of Oslo Norway The importance of proteoglycans for secretion of proteolytic enzymes was studied in the murine macrophage cell line J774. Untreated or 4b-phorbol 12-myristate 13-acetate PMA -stimulated macrophages were treated with hexyl-b-D-thioxyloside to interfere with the attachment of glycosaminoglycan chains to their respective protein cores. Activation of the J774 macrophages with PMA resulted in increased secretion of trypsin-like serine proteinase activity. This activity was completely inhibited by plasminogen activator inhibitor 1 and by amiloride identifying the activity as urokinase plasminogen activator uPA . Treatment of both the unstimulated or PMA-stimulated macrophages with xyloside resulted in decreased uPA activity and Western blotting analysis revealed an almost complete absence of secreted uPA protein after xyloside treatment of either control- or PMA-treated cells. Zymography analyses with gels containing both gelatin and plasminogen confirmed these findings. The xyloside treatment did not reduce the mRNA levels for uPA indicating that the effect was at the post-translational level. Treatment of the macrophages with xylosides did also reduce the levels of secreted matrix metalloproteinase 9. Taken together these findings indicate a role for proteoglycans in the secretion of uPA and MMP-9. Keywords .