Effects of aneurysmal low and supra-high wall shear stress on endothelial gene expression

Wall shear stress (WSS) is proposed to influence intracranial aneurysm growth and rupture. Physiological WSS in cerebral arteries is estimated around 20-30 dynes/cm2. The WSS typically observed in human IAs is close to 2 dynes/cm2 for wide-neck aneurysms with a slow recirculating flow and >70 dynes/cm2 in aneurysms with impinging “jet flow”. In this study, we investigated the effects of aneurysmal low and supra-high WSS on endothelial cells. Overall design: Primary porcine aortic endothelial cells (PECs) used in this study were cultured in DMEM medium supplemented with 10% fetal calf serum and 100 g/mL heparin. For flow experiments, cells were seeded on 1% gelatin coated Ibidi chambers. For low shear stress experiments (2 dynes/cm2), cells were seeded at 30.000 cells per channel in Ibidi µ-Slide VI 0.4. For supra-high shear stress experiments (80 dynes/cm2) cells were seeded at 100.000 cells per channel in Ibidi µ-Slide I 0.2 Luer. The different laminar shear stress conditions were applied for 48h using an Ibidi flow system. To allow comparison between low and physiological (30 dynes/cm2) shear stress, and between supra-high and physiological shear stress, experiments at 30 dynes/cm2 were performed either in Ibidi µ-Slides VI 0.4 (condition named as 302 dynes/cm2) or in Ibidi µ-Slides I 0.2 Luer (condition named as 3080 dynes/cm2), respectively.