Abstract
Induction of urokinase plasminogen activator (uPA) by retinoic acid (RA) is the initial event preceding certain subsequent biological changes in vascular endothelial cells. We investigated the molecular mechanism by which RA stimulates the expression of uPA, which lacks a canonical RA receptor (RAR)-responsive element, in bovine and human aortic endothelial cells. Upon stimulation with RA, mRNA levels of RARα and β transiently increased in parallel with the induction of uPA, and this increase was inhibited by cycloheximide. Results of transient transfection of RAR/RXR cDNAs and experiments using specific agonists and antagonists suggested that uPA induction is dependent upon RAR (initially, RARα) with the help of RXRα. Deletion analysis of the uPA promoter suggested that RAR/RXR acts on GC box region within the uPA promoter. This was further supported by inhibition of Sp1 binding to this region. Coimmunoprecipitation studies, glutathione S- transferase pull-down experiment, and mammalian two-hybrid assays suggested a physical interaction between RAR/RXR and Sp1. Furthermore, gel shift studies showed that the binding of Sp1 to the uPA GC box is significantly potentiated in the presence of RARs/RXRs. Finally, Sp1 and RAR/RXR synergistically enhanced the transactivation activity of the uPA promoter. These results suggest that (1) RA induces RARs mainly via RARα and that (2) RAR/RXR physically and functionally interact with Sp1, resulting in a potentiation of uPA transcription.
| Original language | English |
|---|---|
| Pages (from-to) | 4264-4276 |
| Number of pages | 13 |
| Journal | Blood |
| Volume | 93 |
| Issue number | 12 |
| Publication status | Published - Jun 15 1999 |
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ASJC Scopus subject areas
- Hematology
Cite this
Physical interaction between retinoic acid receptor and Sp1 : Mechanism for induction of urokinase by retinoic acid. / Suzuki, Yasuhiro; Shimada, Jun; Shudo, Koichi; Matsumura, Masatoshi; Crippa, Massimo P.; Kojima, Soichi.
In: Blood, Vol. 93, No. 12, 15.06.1999, p. 4264-4276.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Physical interaction between retinoic acid receptor and Sp1
T2 - Mechanism for induction of urokinase by retinoic acid
AU - Suzuki, Yasuhiro
AU - Shimada, Jun
AU - Shudo, Koichi
AU - Matsumura, Masatoshi
AU - Crippa, Massimo P.
AU - Kojima, Soichi
PY - 1999/6/15
Y1 - 1999/6/15
N2 - Induction of urokinase plasminogen activator (uPA) by retinoic acid (RA) is the initial event preceding certain subsequent biological changes in vascular endothelial cells. We investigated the molecular mechanism by which RA stimulates the expression of uPA, which lacks a canonical RA receptor (RAR)-responsive element, in bovine and human aortic endothelial cells. Upon stimulation with RA, mRNA levels of RARα and β transiently increased in parallel with the induction of uPA, and this increase was inhibited by cycloheximide. Results of transient transfection of RAR/RXR cDNAs and experiments using specific agonists and antagonists suggested that uPA induction is dependent upon RAR (initially, RARα) with the help of RXRα. Deletion analysis of the uPA promoter suggested that RAR/RXR acts on GC box region within the uPA promoter. This was further supported by inhibition of Sp1 binding to this region. Coimmunoprecipitation studies, glutathione S- transferase pull-down experiment, and mammalian two-hybrid assays suggested a physical interaction between RAR/RXR and Sp1. Furthermore, gel shift studies showed that the binding of Sp1 to the uPA GC box is significantly potentiated in the presence of RARs/RXRs. Finally, Sp1 and RAR/RXR synergistically enhanced the transactivation activity of the uPA promoter. These results suggest that (1) RA induces RARs mainly via RARα and that (2) RAR/RXR physically and functionally interact with Sp1, resulting in a potentiation of uPA transcription.
AB - Induction of urokinase plasminogen activator (uPA) by retinoic acid (RA) is the initial event preceding certain subsequent biological changes in vascular endothelial cells. We investigated the molecular mechanism by which RA stimulates the expression of uPA, which lacks a canonical RA receptor (RAR)-responsive element, in bovine and human aortic endothelial cells. Upon stimulation with RA, mRNA levels of RARα and β transiently increased in parallel with the induction of uPA, and this increase was inhibited by cycloheximide. Results of transient transfection of RAR/RXR cDNAs and experiments using specific agonists and antagonists suggested that uPA induction is dependent upon RAR (initially, RARα) with the help of RXRα. Deletion analysis of the uPA promoter suggested that RAR/RXR acts on GC box region within the uPA promoter. This was further supported by inhibition of Sp1 binding to this region. Coimmunoprecipitation studies, glutathione S- transferase pull-down experiment, and mammalian two-hybrid assays suggested a physical interaction between RAR/RXR and Sp1. Furthermore, gel shift studies showed that the binding of Sp1 to the uPA GC box is significantly potentiated in the presence of RARs/RXRs. Finally, Sp1 and RAR/RXR synergistically enhanced the transactivation activity of the uPA promoter. These results suggest that (1) RA induces RARs mainly via RARα and that (2) RAR/RXR physically and functionally interact with Sp1, resulting in a potentiation of uPA transcription.
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UR - http://www.scopus.com/inward/citedby.url?scp=0033564677&partnerID=8YFLogxK
M3 - Article
C2 - 10361124
AN - SCOPUS:0033564677
VL - 93
SP - 4264
EP - 4276
JO - Blood
JF - Blood
SN - 0006-4971
IS - 12
ER -