Transcriptional activation of the urokinase receptor gene by endothelin-1.
Using an immortalized human glomerular epithelial cell line (E71 A1), we studied the effect of endothelin-1 (ET-1), a potent vasoconstrictor peptide, on the synthesis of urokinase type plasminogen activator (u-PA) and its receptor (u-PAR). The results show that ET-1 had no effect on u-PA synthesis but induced an increase in u-PAR number (2.8 +/- 0.6 x 10(4) vs 1.2 +/- 0.5 x 10(4) sites per cell, p less than 0.001) without change in receptor affinity (280 +/- 80 pM vs 250 +/- 50 pM, NS), maximal effect being observed at 10(-7) M. Time course shows that a plateau was reached after a 24 hour incubation. ET-1 induced-increase in binding capacity was abolished by cycloheximide. ET-1 also induced an increase in u-PAR mRNA level, which was completely blocked by alpha-amanitin (5 micrograms/ml). Cycloheximide (1 microgram/ml) alone induced an increase in u-PAR mRNA level and this effect was enhanced when cycloheximide was combined with ET-1. Our data show that ET-1 can induce an increase in membrane expression of u-PAR through activation of the transcription of the u-PAR gene and de novo protein synthesis.
He
C J
CJ
INSERM U 64, Hôpital Tenon, Paris, France.
Nguyen
G
G
Li
X M
XM
Peraldi
M N
MN
Adida
C
C
Rondeau
E
E
Sraer
J D
JD
D000546:Amanitins / Q000494:pharmacology; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D003513:Cycloheximide / Q000494:pharmacology; D016232:Endothelins / Q000502:physiology*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D007678:Kidney Glomerulus / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D011956:Receptors, Cell Surface / Q000235:genetics*; D055293:Receptors, Urokinase Plasminogen Activator; D014158:Transcription, Genetic / Q000502:physiology; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism*
D000546:Amanitins; D016232:Endothelins; C524898:PLAUR protein, human; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator; D003513:Cycloheximide; D014568:Urokinase-Type Plasminogen Activator