Matthias Brock1, Victor J Samillan2, Michelle Trenkmann3, Colin Schwarzwald4, Silvia Ulrich5, Renate E Gay3, Max Gassmann2, Louise Ostergaard2, Steffen Gay3, Rudolf Speich5, Lars C Huber6. 1. Center of Experimental Rheumatology and Zurich Center of Integrative Human Physiology (ZIHP) University Zurich, University Hospital Zurich, Gloriastrasse 23, CH-8091 Zurich, Switzerland Pulmonary Hypertension Working Group, University Hospital Zurich, Zurich, Switzerland matthias.brock@usz.ch. 2. Institute of Veterinary Physiology, Vetsuisse Faculty and Zurich Center of Integrative Human Physiology (ZIHP), University Zurich, Zurich, Switzerland. 3. Center of Experimental Rheumatology and Zurich Center of Integrative Human Physiology (ZIHP) University Zurich, University Hospital Zurich, Gloriastrasse 23, CH-8091 Zurich, Switzerland. 4. Equine Department, Vetsuisse Faculty, University Zurich, Zurich, Switzerland. 5. Pulmonary Hypertension Working Group, University Hospital Zurich, Zurich, Switzerland. 6. Center of Experimental Rheumatology and Zurich Center of Integrative Human Physiology (ZIHP) University Zurich, University Hospital Zurich, Gloriastrasse 23, CH-8091 Zurich, Switzerland Pulmonary Hypertension Working Group, University Hospital Zurich, Zurich, Switzerland.
Abstract
AIMS: Dysregulation of the bone morphogenetic protein receptor type 2 (BMPR2) is a hallmark feature that has been described in several forms of pulmonary hypertension. We recently identified the microRNA miR-20a within a highly conserved pathway as a regulator of the expression of BMPR2. To address the pathophysiological relevance of this pathway in vivo, we employed antagomiR-20a and investigated whether specific inhibition of miR-20a could restore functional levels of BMPR2 and, in turn, might prevent pulmonary arterial vascular remodelling. METHODS AND RESULTS: For specific inhibition of miR-20a, cholesterol-modified RNA oligonucleotides (antagomiR-20a) were synthesized. The experiments in mice were performed by using the hypoxia-induced mouse model for pulmonary hypertension and animal tissues were analysed for right ventricular hypertrophy and pulmonary arterial vascular remodelling. Treatment with antagomiR-20a enhanced the expression levels of BMPR2 in lung tissues; moreover, antagomiR-20a significantly reduced wall thickness and luminal occlusion of small pulmonary arteries and reduced right ventricular hypertrophy. To assess BMPR2 signalling and proliferation, we performed in vitro experiments with human pulmonary arterial smooth muscle cells (HPASMCs). Transfection of HPASMCs with antagomiR-20a resulted in activation of downstream targets of BMPR2 showing increased activation of Id-1 and Id-2. Proliferation of HPASMCs was found to be reduced upon transfection with antagomiR-20a. CONCLUSION: This is the first report showing that miR-20a can be specifically targeted in an in vivo model for pulmonary hypertension. Our data emphasize that treatment with antagomiR-20a restores functional levels of BMPR2 in pulmonary arteries and prevents the development of vascular remodelling. Published on behalf of the European Society of Cardiology. All rights reserved.
AIMS: Dysregulation of the bone morphogenetic protein receptor type 2 (BMPR2) is a hallmark feature that has been described in several forms of pulmonary hypertension. We recently identified the microRNA miR-20a within a highly conserved pathway as a regulator of the expression of BMPR2. To address the pathophysiological relevance of this pathway in vivo, we employed antagomiR-20a and investigated whether specific inhibition of miR-20a could restore functional levels of BMPR2 and, in turn, might prevent pulmonary arterial vascular remodelling. METHODS AND RESULTS: For specific inhibition of miR-20a, cholesterol-modified RNA oligonucleotides (antagomiR-20a) were synthesized. The experiments in mice were performed by using the hypoxia-induced mouse model for pulmonary hypertension and animal tissues were analysed for right ventricular hypertrophy and pulmonary arterial vascular remodelling. Treatment with antagomiR-20a enhanced the expression levels of BMPR2 in lung tissues; moreover, antagomiR-20a significantly reduced wall thickness and luminal occlusion of small pulmonary arteries and reduced right ventricular hypertrophy. To assess BMPR2 signalling and proliferation, we performed in vitro experiments with human pulmonary arterial smooth muscle cells (HPASMCs). Transfection of HPASMCs with antagomiR-20a resulted in activation of downstream targets of BMPR2 showing increased activation of Id-1 and Id-2. Proliferation of HPASMCs was found to be reduced upon transfection with antagomiR-20a. CONCLUSION: This is the first report showing that miR-20a can be specifically targeted in an in vivo model for pulmonary hypertension. Our data emphasize that treatment with antagomiR-20a restores functional levels of BMPR2 in pulmonary arteries and prevents the development of vascular remodelling. Published on behalf of the European Society of Cardiology. All rights reserved.
Authors: Jared M McLendon; Sachindra R Joshi; Jeff Sparks; Majed Matar; Jason G Fewell; Kohtaro Abe; Masahiko Oka; Ivan F McMurtry; William T Gerthoffer Journal: J Control Release Date: 2015-05-13 Impact factor: 9.776
Authors: Lars C Huber; Silvia Ulrich; Caroline Leuenberger; Max Gassmann; Johannes Vogel; Leonardo Glutz von Blotzheim; Rudolf Speich; Malcolm Kohler; Matthias Brock Journal: Exp Biol Med (Maywood) Date: 2015-04-07