Comparison of Different Osteogenic Media to Induce Aortic Valve Calcification <i>In Vitro</i>

Background Experimentally induced calcification in primary human aortic valve interstitial cells (VICs) is a good in vitro model for studying calcific aortic valve disease. Mesenchymal stem cells (MSCs) may be used as a substitute for VICs. The aims of the present study were: 1. To compare six commonly used osteogenic media for inducing calcification in human VICs; 2. To assess any difference in calcification between VICs and MSCs caused by the different media; 3. To study the expression of pro-osteogenic genes in both cell types within the same experimental framework. Methods Cultures of VICs ( n = 6) and MSCs ( n = 5) were exposed to six different osteogenic media. Calcification was measured spectrophotometrically after Alizarin Red staining on the 3 rd , 7 th , 10 th , 14 th , 18 th , and 21 st day. Expression of pro-calcification genes was determined by qPCR on the 4 th , 7 th , and 14 th day. Results VICs were more prone to calcification compared to MSCs. Two of the media were toxic for VICs. MSCs maintained their morphology and functionality in all osteogenic media. Expression of pro-osteogenic genes differed significantly with the different media and between VICs and MSCs. Conclusion There were major differences between the media tested and between MSCs and VICs in response to induced calcification. MSCs are inferior for studying aortic valve calcification in vitro .