[HTML][HTML] Long term stabilization of expanding aortic aneurysms by a short course of cyclosporine A through transforming growth factor-beta induction

J Dai, S Michineau, G Franck, P Desgranges… - PloS one, 2011 - journals.plos.org
J Dai, S Michineau, G Franck, P Desgranges, JP Becquemin, M Gervais, E Allaire
PloS one, 2011journals.plos.org
Abdominal aortic aneurysms (AAAs) expand as a consequence of extracellular matrix
destruction, and vascular smooth muscle cell (VSMC) depletion. Transforming growth factor
(TGF)-beta 1 overexpression stabilizes expanding AAAs in rat. Cyclosporine A (CsA)
promotes tissue accumulation and induces TGF-beta1 and, could thereby exert beneficial
effects on AAA remodelling and expansion. In this study, we assessed whether a short
administration of CsA could durably stabilize AAAs through TGF-beta induction. We showed …
Abdominal aortic aneurysms (AAAs) expand as a consequence of extracellular matrix destruction, and vascular smooth muscle cell (VSMC) depletion. Transforming growth factor (TGF)-beta 1 overexpression stabilizes expanding AAAs in rat. Cyclosporine A (CsA) promotes tissue accumulation and induces TGF -beta1 and, could thereby exert beneficial effects on AAA remodelling and expansion. In this study, we assessed whether a short administration of CsA could durably stabilize AAAs through TGF-beta induction. We showed that CsA induced TGF-beta1 and decreased MMP-9 expression dose-dependently in fragments of human AAAs in vitro, and in animal models of AAA in vivo. CsA prevented AAA formation at 14 days in the rat elastase (diameter increase: CsA: 131.9±44.2%; vehicle: 225.9±57.0%, P = 0.003) and calcium chloride mouse models (diameters: CsA: 0.72±0.14 mm; vehicle: 1.10±0.11 mm, P = .008), preserved elastic fiber network and VSMC content, and decreased inflammation. A seven day administration of CsA stabilized formed AAAs in rats seven weeks after drug withdrawal (diameter increase: CsA: 14.2±15.1%; vehicle: 45.2±13.7%, P = .017), down-regulated wall inflammation, and increased αSMA-positive cell content. Co-administration of a blocking anti-TGF-beta antibody abrogated CsA impact on inflammation, αSMA-positive cell accumulation and diameter control in expanding AAAs. Our study demonstrates that pharmacological induction of TGF-beta1 by a short course of CsA administration represents a new approach to induce aneurysm stabilization by shifting the degradation/repair balance towards healing.
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