Involvement of Rho GTPases in the transcriptional inhibition of preproendothelin-1 gene expression by simvastatin in vascular endothelial cells.
Endothelial dysfunction is characterized by an impaired vasodilatory response to endothelial agonists as well as by alterations in adhesion and coagulation processes. 3-Hydroxy-3-methylglutaryl-CoA reductase inhibitors (statins) have been shown to be useful in the reversal of endothelial dysfunction, an effect that may be independent of the reduction in cholesterol levels. Both the L-arginine-nitric oxide-cGMP and endothelin pathways are involved in the regulation of vascular tone. Here, we show that the basal transcription rate of the preproendothelin-1 gene was decreased by simvastatin (10 micromol/L) in bovine aortic endothelial cells. Transfection studies with the preproendothelin-1 gene promoter showed that mevalonate (100 micromol/L) was able to prevent the inhibitory effect mediated by simvastatin. Protein geranylgeranylation, but not farnesylation, proved to be crucial for a correct expression of the preproendothelin-1 gene. The C3 exotoxin from Clostridium botulinum that selectively inactivates Rho GTPases, the processing of which involves geranylgeranylation, reproduced the inhibitory effect of simvastatin on the expression of preproendothelin-1. Overexpression of dominant-negative mutants of RhoA and RhoB led to a significant reduction in the preproendothelin-1 promoter activity, whereas the expression of wild-type and constitutively active forms of these proteins resulted in an increase, in support that Rho proteins are required for the basal expression of the preproendothelin-1 gene. Finally, we show that the Rho-dependent activation of the preproendothelin-1 gene transcription was inhibited by simvastatin. Thus, the control of vascular tone and proliferative response mediated by endothelin-1 is regulated at multiple levels, among which the Rho proteins play an essential role.
Hernández-Perera
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Centro de Investigaciones Biológicas, and Instituto "Reina Sofía" de Investigaciones Nefrológicas, Consejo Superior de Investigaciones Científicas, Velázquez, Madrid, Spain.
Pérez-Sala
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D
Soria
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Lamas
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D019883:Alkyl and Aryl Transferases / Q000037:antagonists & inhibitors / Q000378:metabolism; D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D004347:Drug Interactions; D019332:Endothelin-1; D016232:Endothelins / Q000235:genetics*; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000502:physiology; D051231:Farnesyltranstransferase; D005786:Gene Expression Regulation / Q000187:drug effects*; D008798:Mevalonic Acid / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism; D011106:Polyisoprenyl Phosphates / Q000494:pharmacology; D011498:Protein Precursors / Q000235:genetics*; D012717:Sesquiterpenes; D019821:Simvastatin / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects; D020741:rho GTP-Binding Proteins / Q000037:antagonists & inhibitors / Q000502:physiology*
D019332:Endothelin-1; D016232:Endothelins; D011106:Polyisoprenyl Phosphates; D011498:Protein Precursors; D012717:Sesquiterpenes; D009569:Nitric Oxide; C004808:farnesyl pyrophosphate; D019821:Simvastatin; D019883:Alkyl and Aryl Transferases; C083291:geranylgeranyltransferase type-I; D051231:Farnesyltranstransferase; D020741:rho GTP-Binding Proteins; C002963:geranylgeranyl pyrophosphate; D008798:Mevalonic Acid