Activity of the Estrogen-Metabolizing Enzyme Cytochrome P450 1B1 Influences the Development of Pulmonary Arterial Hypertension

White, K. et al. (2012) Activity of the Estrogen-Metabolizing Enzyme Cytochrome P450 1B1 Influences the Development of Pulmonary Arterial Hypertension. Circulation, 126(9), pp. 1087-1098. (doi:10.1161/CIRCULATIONAHA.111.062927)

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Publisher's URL: http://dx.doi.org/10.1161/CIRCULATIONAHA.111.062927

Abstract

<b>Background—</b> Pulmonary arterial hypertension (PAH) is a hyperproliferative vascular disorder observed predominantly in women. Estrogen is a potent mitogen in human pulmonary artery smooth muscle cells and contributes to PAH in vivo; however, the mechanisms attributed to this causation remain obscure. Curiously, heightened expression of the estrogen-metabolizing enzyme cytochrome P450 1B1 (CYP1B1) is reported in idiopathic PAH and murine models of PAH. <p></p> <b>Methods and Results—</b> Here, we investigated the putative pathogenic role of CYP1B1 in PAH. Quantitative reverse transcription–polymerase chain reaction, immunoblotting, and in situ analysis revealed that pulmonary CYP1B1 is increased in hypoxic PAH, hypoxic+SU5416 PAH, and human PAH and is highly expressed within the pulmonary vascular wall. PAH was assessed in mice via measurement of right ventricular hypertrophy, pulmonary vascular remodeling, and right ventricular systolic pressure. Hypoxic PAH was attenuated in CYP1B1−/− mice, and the potent CYP1B1 inhibitor 2,3′,4,5′-tetramethoxystilbene (TMS; 3 mg • kg<sup>−1</sup> • d<sup>−1</sup> IP) significantly attenuated hypoxic PAH and hypoxic+SU5416 PAH in vivo. TMS also abolished estrogen-induced proliferation in human pulmonary artery smooth muscle cells and PAH–pulmonary artery smooth muscle cells. The estrogen metabolite 16α-hydroxyestrone provoked human pulmonary artery smooth muscle cell proliferation, and this mitogenic effect was greatly pronounced in PAH–pulmonary artery smooth muscle cells. ELISA analysis revealed that 16α-hydroxyestrone concentration was elevated in PAH, consistent with CYP1B1 overexpression and activity. Finally, administration of the CYP1B1 metabolite 16α -hydroxyestrone (1.5 mg • kg−1 • d−1 IP) caused the development of PAH in mice. <p></p> <b>Conclusions—</b> Increased CYP1B1-mediated estrogen metabolism promotes the development of PAH, likely via the formation of mitogens, including 16α -hydroxyestrone. Collectively, this study reveals a possible novel therapeutic target in clinical PAH. <p></p>

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:MacLean, Professor Margaret and Loughlin, Mrs Lynn and Nilsen, Mrs Margaret and Johansen, Miss Anne Katrine and Morecroft, Dr Ian and Mair, Dr Kirsty and White, Dr Kevin and McClure, Dr John
Authors: White, K., Johansen, A. K., Nilsen, M., Ciuclan, L., Wallace, E., Paton, L., Campbell, A., Morecroft, I., Loughlin, L., McClure, J. D., Thomas, M., Mair, K. M., and MacLean, M. R.
College/School:College of Medical Veterinary and Life Sciences > Institute of Cardiovascular and Medical Sciences
Journal Name:Circulation
Publisher:Lippincott Williams & Wilkins
ISSN:0009-7322
ISSN (Online):1524-4539
Published Online:02 August 2012
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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
536791Effect of oestrogens and oestrogen metabolites on the serotonin system: role in the development of pulmonary hypertensionMargaret MacleanBritish Heart Foundation (BHF)FS/10/019/28205RI CARDIOVASCULAR & MEDICAL SCIENCES
573731Gender and the development of pulmonary arterial hypertension: regulation of genes from mouse to manMargaret MacleanBritish Heart Foundation (BHF)RG/11/7/28916RI CARDIOVASCULAR & MEDICAL SCIENCES
573733Gender and the development of pulmonary arterial hypertension: regulation of genes from mouse to manMargaret MacleanBritish Heart Foundation (BHF)RG/11/7/28916RI CARDIOVASCULAR & MEDICAL SCIENCES