Off-target vascular effects of cholesteryl ester transfer protein inhibitors involve redox-sensitive and signal transducer and activator of transcription 3-dependent pathways

Rios, F. J., Lopes, R. A., Neves, K. B., Camargo, L. L., Montezano, A. C. and Touyz, R. M. (2016) Off-target vascular effects of cholesteryl ester transfer protein inhibitors involve redox-sensitive and signal transducer and activator of transcription 3-dependent pathways. Journal of Pharmacology and Experimental Therapeutics, 357(2), pp. 415-422. (doi:10.1124/jpet.115.230748) (PMID:26941168)

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Abstract

Elevated blood pressure was an unexpected outcome in some cholesteryl ester transfer protein (CETP) inhibitor trials, possibly due to vascular effects of these drugs. We investigated whether CETP inhibitors (torcetrapib, dalcetrapib, anacetrapib) influence vascular function and explored the putative underlying molecular mechanisms. Resistance arteries and vascular smooth muscle cells (VSMC) from rats, which lack the CETP gene, were studied. CETP inhibitors increased phenylephrine-stimulated vascular contraction (logEC50: 6.6 ± 0.1; 6.4 ± 0.06, and 6.2 ± 0.09 for torcetrapib, dalcetrapib, and anacetrapib, respectively, versus control 5.9 ± 0.05). Only torcetrapib reduced endothelium-dependent vasorelaxation. The CETP inhibitor effects were ameliorated by N-acetylcysteine (NAC), a reactive oxygen species (ROS) scavenger, and by S3I-201 [2-hydroxy-4-[[2-(4-methylphenyl)sulfonyloxyacetyl]amino]benzoic acid], a signal transducer and activator of transcription 3 (STAT3) inhibitor. CETP inhibitors increased the phosphorylation (2- to 3-fold) of vascular myosin light chain (MLC) and myosin phosphatase target subunit 1 (MYPT1) (procontractile proteins) and stimulated ROS production. CETP inhibitors increased the phosphorylation of STAT3 (by 3- to 4-fold), a transcription factor important in cell activation. Activation of MLC was reduced by NAC, GKT137831 [2-(2-chlorophenyl)-4-[3-(dimethylamino)phenyl]-5-methyl-1H-pyrazolo[4,3-c]pyridine-3,6-dione] (Nox1/4 inhibitor), and S3I-201. The phosphorylation of STAT3 was unaffected by NAC and GKT137831. CETP inhibitors did not influence activation of mitogen-activated proteins kinases (MAPK) or c-Src. Our data demonstrate that CETP inhibitors influence vascular function and contraction through redox-sensitive, STAT3-dependent, and MAPK-independent processes. These phenomena do not involve CETP because the CETP gene is absent in rodents. Findings from our study indicate that CETP inhibitors have vasoactive properties, which may contribute to the adverse cardiovascular effects of these drugs such as hypertension.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Montezano, Dr Augusto and Touyz, Professor Rhian and Rios, Dr Francisco
Authors: Rios, F. J., Lopes, R. A., Neves, K. B., Camargo, L. L., Montezano, A. C., and Touyz, R. M.
College/School:College of Medical Veterinary and Life Sciences > Institute of Cardiovascular and Medical Sciences
Journal Name:Journal of Pharmacology and Experimental Therapeutics
Publisher:American Society for Pharmacology and Experimental Therapeutics
ISSN:0022-3565
ISSN (Online):1521-0103
Published Online:03 March 2016

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
607381Vascular Noxs as therapeutic targets and biomarkers in hypertensionRhian TouyzBritish Heart Foundation (BHF)CH/12/4/29762RI CARDIOVASCULAR & MEDICAL SCIENCES
607382Vascular Noxs as therapeutic targets and biomarkers in hypertensionRhian TouyzBritish Heart Foundation (BHF)RG/13/7/30099RI CARDIOVASCULAR & MEDICAL SCIENCES