Lack of cyclic stretch disturbs endothelial cell transcriptomic profile

Cyclic circumferential stretch (CCS) induced by pulsatile blood pressure affects endothelial cell (EC) gene expression and regulates vascular mechanical properties. Although alterations in EC gene expression in response to increased CCS as observed in hypertensive patients is widely studied, the EC response to low or lack of CCS as observed in intracranial aneurysm (IA) disease has been poorly investigated. In this project we explored how exposure of ECs to low CCS may contribute to IA disease. Overall design: HUVECS were seeded at 300'000 cells/well on pre-coated Collagen I BioFlex culture plates® (Flexcell International, USA) and grown until confluence. Then, the cells were submitted to cyclic stretch of 6% or not (0%) for 48-hours using the Flexcell strain unit FX-5000T (Flexcell International, USA) according to the manufacturers' instructions. Thus, the cells were stretched over a 25mm loading station or maintain under static condition (0%) by placing a Flexstop beneath the well of the BioFlex culture plate. The mechanical stretch was applied following the pulse heart waveform with a frequency of 1Hz (Figure 1D). After 48-hours, we collected the cells that received a uniform strain.