Transcriptional profiles of valvular and vascular endothelial cells reveal phenotypic differences: influence of 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.


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
Jonathan T
JT
Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia, USA.
Tressel
Sarah
S
Johnson
Tiffany
T
Turner
Debi
D
Sorescu
George
G
Jo
Hanjoong
H
Nerem
Robert M
RM
D000818:Animals; D000975:Antioxidants / Q000502:physiology; D001011:Aorta / Q000166:cytology*; D001021:Aortic Valve / Q000166:cytology*; D002114:Calcinosis / Q000235:genetics; D020219:Chondrogenesis / Q000235:genetics; D042783:Endothelial Cells / Q000166:cytology / Q000502:physiology*; D020869:Gene Expression Profiling; D007249:Inflammation / Q000235:genetics; D018836:Inflammation Mediators / Q000502:physiology; D020411:Oligonucleotide Array Sequence Analysis; D010012:Osteogenesis / Q000235:genetics; D018384:Oxidative Stress / Q000235:genetics; D010641:Phenotype; D013314:Stress, Mechanical; D013552:Swine; D014158:Transcription, Genetic / Q000502:physiology*
D000975:Antioxidants; D018836:Inflammation Mediators