Exposure of porcine aortic and valvular endothelial cells to shear stress revealed >400 differentially expressed genes, showing PAVECs are less intrinsically inflammatory than PAECs.
Does steady laminar shear stress alter the transcriptional profiles of porcine aortic and valvular endothelial cells compared to static conditions?
Transcriptional differences between valvular and vascular endothelial cells highlight the valvular endothelium as a distinct organ system with unique responses to shear stress.
OBJECTIVE: The similarities between valvular and vascular lesions suggest pathological initiation mediated through endothelium, but the role of hemodynamics in valvular endothelial biology is poorly understood. METHODS AND RESULTS: Monolayers of porcine aortic endothelial cells (PAECs) or porcine aortic valve endothelial cells (PAVECs) were exposed to 20 dyne/cm2 steady laminar shear stress for 48 hours, with static cultures serving as controls. Multiple microarray comparisons were made using RNA from sheared and control batches of both cell types. More than 400 genes were significantly differentially expressed in each comparison group. The resulting profiles were validated at the transcription and protein level and expression patterns confirmed in vivo by immunohistochemistry. PAVECs were found to be less intrinsically inflammatory than PAECs, but both cell types expressed similar antioxidant and antiinflammatory genes in response to shear stress. PAVECs expressed more genes associated with chondrogenesis, whereas PAECs expressed osteogenic genes, and shear stress had a protective effect against calcification. CONCLUSIONS: Transcriptional differences between PAVECs and PAECs highlight the valvular endothelial cell as a distinct organ system and suggest more attention needs to be given to valvular cells to further our understanding of similarities and differences between valvular and vascular pathology.
Butcher et al. (Fri,) conducted a other in Valvular and vascular endothelial biology. Steady laminar shear stress vs. Static cultures was evaluated on Differentially expressed genes. Exposure of porcine aortic and valvular endothelial cells to shear stress revealed >400 differentially expressed genes, showing PAVECs are less intrinsically inflammatory than PAECs.