Endothelial repair in stented arteries is accelerated by inhibition of Rho-associated protein kinase

Cardiovasc Res. 2016 Dec;112(3):689-701. doi: 10.1093/cvr/cvw210. Epub 2016 Sep 26.

Abstract

Aims: Stent deployment causes endothelial cells (EC) denudation, which promotes in-stent restenosis and thrombosis. Thus endothelial regrowth in stented arteries is an important therapeutic goal. Stent struts modify local hemodynamics, however the effects of flow perturbation on EC injury and repair are incompletely understood. By studying the effects of stent struts on flow and EC migration, we identified an intervention that promotes endothelial repair in stented arteries.

Methods and results: In vitro and in vivo models were developed to monitor endothelialization under flow and the influence of stent struts. A 2D parallel-plate flow chamber with 100 μm ridges arranged perpendicular to the flow was used. Live cell imaging coupled to computational fluid dynamic simulations revealed that EC migrate in the direction of flow upstream from the ridges but subsequently accumulate downstream from ridges at sites of bidirectional flow. The mechanism of EC trapping by bidirectional flow involved reduced migratory polarity associated with altered actin dynamics. Inhibition of Rho-associated protein kinase (ROCK) enhanced endothelialization of ridged surfaces by promoting migratory polarity under bidirectional flow (P < 0.01). To more closely mimic the in vivo situation, we cultured EC on the inner surface of polydimethylsiloxane tubing containing Coroflex Blue stents (65 μm struts) and monitored migration. ROCK inhibition significantly enhanced EC accumulation downstream from struts under flow (P < 0.05). We investigated the effects of ROCK inhibition on re-endothelialization in vivo using a porcine model of EC denudation and stent placement. En face staining and confocal microscopy revealed that inhibition of ROCK using fasudil (30 mg/day via osmotic minipump) significantly increased re-endothelialization of stented carotid arteries (P < 0.05).

Conclusions: Stent struts delay endothelial repair by generating localized bidirectional flow which traps migrating EC. ROCK inhibitors accelerate endothelial repair of stented arteries by enhancing EC polarity and migration through regions of bidirectional flow.

Keywords: Endothelial cells; Fasudil; ROCK; Shear stress; Stent.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / analogs & derivatives*
  • 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / pharmacology
  • Actin Depolymerizing Factors / metabolism
  • Actins / metabolism
  • Angioplasty, Balloon / instrumentation*
  • Animals
  • Carotid Arteries / drug effects*
  • Carotid Arteries / enzymology
  • Carotid Arteries / pathology
  • Carotid Arteries / physiopathology
  • Cell Movement / drug effects*
  • Cells, Cultured
  • Computer Simulation
  • Endothelial Cells / drug effects*
  • Endothelial Cells / enzymology
  • Endothelial Cells / pathology
  • Hemodynamics / drug effects
  • Human Umbilical Vein Endothelial Cells / drug effects
  • Human Umbilical Vein Endothelial Cells / enzymology
  • Humans
  • Hydrodynamics
  • Male
  • Models, Animal
  • Models, Cardiovascular
  • Myosin Light Chains / metabolism
  • Phenotype
  • Prosthesis Design
  • Protein Kinase Inhibitors / pharmacology*
  • Re-Epithelialization / drug effects*
  • Regional Blood Flow
  • Signal Transduction / drug effects
  • Stents*
  • Sus scrofa
  • Time Factors
  • rho-Associated Kinases / antagonists & inhibitors*
  • rho-Associated Kinases / metabolism

Substances

  • Actin Depolymerizing Factors
  • Actins
  • Myosin Light Chains
  • Protein Kinase Inhibitors
  • 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine
  • rho-Associated Kinases
  • fasudil