Activation of gelatinases by fibrin is PA/plasmin system-dependent in human glomerular endothelial cells.
Evidence suggests that fibrin deposit is related to severity of glomerulonephropathy. Fibrin is considered to play an active role beyond a haemostatic plug or temporary matrix in response to injury. We have reported that fibrin induced specific morphological changes and up-regulated intercellular adhesion molecule-1 expression of glomerular endothelial cells (GECs). Changes of gelatinases activity have been implicated playing a prominent role in glomerular diseases involving matrix turnover. This study examined whether overlying fibrin influences the expression of gelatinase A and B in cultured human GECs and mechanism underlying the activation. No gelatinase activity was detectable in supernatant of cultured GECs; however, physiological concentration of fibrin (0.5-2.0 mg/ml) induced a dramatic expression of activated MMP-2 and MMP-9 at both mRNA and protein level in a dose and time dependent manner. Increased mRNA level of membrane-type 1 matrix metalloproteinases (MT1-MMPs) was also found. Interestingly, we observed that fibrin also induced the expression of tissue type plasminogen activator (tPA), urokinase type plasminogen activator (uPA) and plasminogen activator inhibitor-1 by casein zymographic and reverse zymographic analysis. Fibrin plate assay revealed the net activity was PA predominant. Serine protease inhibitor aprotinin blocked the conversion of pro-gelatinase A and B to their active forms. The results demonstrate that overlying fibrin increased the secretion of gelatinase A and B from GECs. PA/plasmin proteolytic pathways contributed to the activation of gelatinases.
Cai
Guangyan
G
Department of Nephrology, Kidney Center and Key Laboratory of PLA, General Hospital of PLA, Beijing, P.R. China.
Chen
Xiangmei
X
Fu
Bo
B
Lu
Yang
Y
D001483:Base Sequence; D002478:Cells, Cultured; D004247:DNA / Q000235:genetics; D042783:Endothelial Cells / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D005337:Fibrin / Q000494:pharmacology*; D005341:Fibrinolysin / Q000378:metabolism*; D018093:Gelatinases / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007678:Kidney Glomerulus / Q000187:drug effects / Q000378:metabolism*; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases / Q000235:genetics / Q000378:metabolism; D010960:Plasminogen Activators / Q000378:metabolism*; D015849:Plasminogen Inactivators / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
D015849:Plasminogen Inactivators; D012333:RNA, Messenger; D005337:Fibrin; D004247:DNA; D010960:Plasminogen Activators; D005341:Fibrinolysin; D018093:Gelatinases; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9