Stainless steel ions stimulate increased thrombospondin-1-dependent tgf-beta activation by vascular smooth muscle cells: Implications for in-stent restenosis

Academic Article

Abstract

  • Background/Aims: Despite advances in stent design, in-stent restenosis (ISR) remains a significant clinical problem. All implant metals exhibit corrosion, which results in release of metal ions. Stainless steel (SS), a metal alloy widely used in stents, releases ions to the vessel wall and induces reactive oxygen species, inflammation and fibroproliferative responses. The molecular mechanisms are unknown. TGF-β is known to be involved in the fibroproliferative responses of vascular smooth muscle cells (VSMCs) in restenosis, and TGF-β antagonists attenuate ISR. We hypothesized that SS ions induce the latent TGF-β activator, thrombospondin-1 (TSP1), through altered oxidative signaling to stimulate increased TGF-β activation and VSMC phenotype change. Methods: VSMCs were treated with SS metal ion cocktails, and morphology, TSP1, extracellular matrix production, desmin and TGF-β activity were assessed by immunoblotting. Results: SS ions stimulate the synthetic phenotype, increased TGF-β activity, TSP1, increased extracellular matrix and downregulation of desmin in VSMCs. Furthermore, SS ions increase hydrogen peroxide and decrease cGMP-dependent protein kinase (PKG) signaling, a known repressor of TSP1 transcription. Catalase blocks SS ion attenuation of PKG signaling and increased TSP1 expression. Conclusions: These data suggest that ions from stent alloy corrosion contribute to ISR through stimulation of TSP1-dependent TGF-β activation. © 2009 S. Karger AG, Basel.
  • Digital Object Identifier (doi)

    Author List

  • Pallero MA; Talbert Roden M; Chen YF; Anderson PG; Lemons J; Brott BC; Murphy-Ullrich JE
  • Start Page

  • 309
  • End Page

  • 322
  • Volume

  • 47
  • Issue

  • 4