Dr. Hobbs has received consulting fees, speaking fees, and/or honoraria from Bayer AG, Novartis, and Palatin Technologies (less than $10,000 each).
Endothelial Injury in a Transforming Growth Factor β–Dependent Mouse Model of Scleroderma Induces Pulmonary Arterial Hypertension
Article first published online: 28 OCT 2013
Copyright © 2013 by the American College of Rheumatology
Arthritis & Rheumatism
Volume 65, Issue 11, pages 2928–2939, November 2013
How to Cite
Derrett-Smith, E. C., Dooley, A., Gilbane, A. J., Trinder, S. L., Khan, K., Baliga, R., Holmes, A. M., Hobbs, A. J., Abraham, D. and Denton, C. P. (2013), Endothelial Injury in a Transforming Growth Factor β–Dependent Mouse Model of Scleroderma Induces Pulmonary Arterial Hypertension. Arthritis & Rheumatism, 65: 2928–2939. doi: 10.1002/art.38078
- Issue published online: 28 OCT 2013
- Article first published online: 28 OCT 2013
- Accepted manuscript online: 9 JUL 2013 02:31PM EST
- Manuscript Accepted: 27 JUN 2013
- Manuscript Received: 3 OCT 2012
- Arthritis Research UK. Grant Numbers: 17982, 19700, 19427
- Scleroderma Research Foundation
- British Heart Foundation
To delineate the constitutive pulmonary vascular phenotype of the TβRIIΔk-fib mouse model of scleroderma, and to selectively induce pulmonary endothelial cell injury using vascular endothelial growth factor (VEGF) inhibition to develop a model with features characteristic of pulmonary arterial hypertension (PAH).
The TβRIIΔk-fib mouse strain expresses a kinase-deficient transforming growth factor β (TGFβ) receptor type II driven by a fibroblast-specific promoter, leading to ligand-dependent up-regulation of TGFβ signaling, and replicates key fibrotic features of scleroderma. Structural, biochemical, and functional assessments of pulmonary vessels, including in vivo hemodynamic studies, were performed before and following VEGF inhibition, which induced pulmonary endothelial cell apoptosis. These assessments included biochemical analysis of the TGFβ and VEGF signaling axes in tissue sections and explanted smooth muscle cells.
In the TβRIIΔk-fib mouse strain, a constitutive pulmonary vasculopathy with medial thickening, a perivascular proliferating chronic inflammatory cell infiltrate, and mildly elevated pulmonary artery pressure resembled the well-described chronic hypoxia model of pulmonary hypertension. Following administration of SU5416, the pulmonary vascular phenotype was more florid, with pulmonary arteriolar luminal obliteration by apoptosis-resistant proliferating endothelial cells. These changes resulted in right ventricular hypertrophy, confirming hemodynamically significant PAH. Altered expression of TGFβ and VEGF ligand and receptor was consistent with a scleroderma phenotype.
In this study, we replicated key features of systemic sclerosis–related PAH in a mouse model. Our results suggest that pulmonary endothelial cell injury in a genetically susceptible mouse strain triggers this complication and support the underlying role of functional interplay between TGFβ and VEGF, which provides insight into the pathogenesis of this disease.