Aortic stenosis and atherosclerosis tend to coexist in most patients with cardiovascular disease; however, the causes and mechanisms of calcification are still not clearly understood. To understand the contributions of physiological (10%) and pathological (5%, 15%) levels of cyclic strain in calcification, we used a model system of tissue-engineered collagen gels containing human aortic smooth muscle cells (HASMC) and human aortic valvular interstitial cells (HAVIC), both isolated from non-calcific heart transplant tissues. The tissue engineered collagen gels were cultured in standard osteogenic media for three weeks in a custom designed bioreactor and all assessments were performed at the end of the culture period. The major finding of this study was that bone morphogenic protein (BMP) -2, -4 and transforming growth factor (TGF)-β1 mRNA expression significantly changed in response to the magnitude of strain in valvular cells, while the least expression was observed for the representative 10% physiological strain. On the other hand, these mRNA expressions in vascular cells responded to strain, but did not vary due to the magnitude (5% versus 10% versus 15%) of strain. When the BMP-2 and BMP-4 protein expression was detected using immunostaining, we observed that only valvular cells showed greater BMP-2 expression for 5% and 15% strain when compared to 10% strain within the same cell type. Our results suggest that cell mediated differences exist between vascular and valvular cells in their response to different levels of cyclic strain.


Article metrics loading...

Loading full text...

Full text loading...

  • Accepted: 24 May 2012
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error