title: Effects of statin treatment and withdrawal on angiotensin II-induced phosphorylation of p38 MAPK and ERK1/2 in cultured vascular smooth muscle cells.
abstract: Abrupt discontinuation of 3-hydroxy-3-methylglutaryl-coenzyme-A-reductase inhibitors (statins) is associated with increased cardiovascular risk. To investigate the molecular mechanisms determining the increased cardiovascular risk after statin withdrawal, we studied the effects of statin treatment and withdrawal on angiotensin II (AII) actions in rat aortic vascular smooth muscle cells (VSMC) in culture. In VSMC, AII stimulated the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), and of p38 mitogen-activated protein kinase (p38 MAPK), with an EC50% of 0.86 and 3 nM, respectively. Maximal stimulation was observed after 5-10 min of exposure to AII. Pretreatment with 1-3 microM simvastatin for 24h inhibited AII-mediated stimulation of ERK1/2 and p38 MAPK phosphorylation; without affecting the levels on non-phosphorylated MAPK. Washout of simvastatin produced a rebound increase above control levels of AII-mediated phosphorylation of ERK1/2 and p38 MAPK. As previously reported for other agonists, the rebound increase of AII effects was observed from 1 to 3h after statin withdrawal, and was lost at later times. The basal levels of phosphorylation and the amount of non-phosphorylated kinases were unaffected by statin withdrawal. Similar effects were observed with lovastatin. Our results suggest that statins modulate AII effects in VSMC, and that transient increases in AII effects mediated via the MAPK pathway may play a role in the vascular dysfunction associated with statin withdrawal.
authors.affiliation: Department of Pharmaceutical and Administrative Sciences, College of Pharmacy, Health Professions Division, NOVA Southeastern University, Fort Lauderdale, FL 33328, USA.
authors.forename: Antonio G
authors.initials: AG
authors.lastname: Tristano
authors.forename: Ana M
authors.initials: AM
authors.lastname: Castejon
authors.forename: Amy
authors.initials: A
authors.lastname: Castro
authors.forename: Luigi X
authors.initials: LX
authors.lastname: Cubeddu
mesh_terms: D000804:Angiotensin II / Q000008:administration & dosage*; D000818:Animals; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000008:administration & dosage*; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology; D008297:Male; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
chemical_list: D004338:Drug Combinations; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D000804:Angiotensin II; D019950:Mitogen-Activated Protein Kinase 1; D048051:p38 Mitogen-Activated Protein Kinases