Statin therapy influences endothelial cell morphology and F-actin cytoskeleton structure when exposed to static and laminar shear stress conditions.

Aims: To determine how statin drugs (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) affect endothelial cell (EC) shape and F-actin cytoskeleton arrangement in the presence of physiologically relevant wall shear stress (WSS) of 12.5dyn/cm(2).

Main Methods: Human abdominal aortic endothelial cells (HAAECs) were cultured to a confluent monolayer within three dimensional tissue culture models and presheared for 6h at 12.5 dyn/cm(2) within a continuous flow loop. Statins were added to the perfusion media and the perfusion was continued for a further 24h. ECs were then analyzed for morphology and F-actin cytoskeleton arrangement using light microscopy and laser scanning confocal microscopy.

Key Findings: ECs became rounded with a significantly higher shape index with the addition of 10μM simvastatin under both static and flow conditions. F-actin cytoskeleton structure was disorganized and fragmented with statin treatment under static and flow conditions. Neither of these findings were observed with the addition of both simvastatin and 200μM mevalonate, confirming regulation through the cholesterol biosynthesis pathway.

Significance: EC morphology and F-actin cytoskeleton arrangement are regulated through the cholesterol biosynthesis pathway and are therefore impacted by statin treatment. ECs treated with statins became rounded, which is usually associated with unhealthy cells in regions of the vasculature prone to developing atherosclerotic plaques.