Comparative study of human aortic and mitral valve interstitial cell gene expression and cellular function.

Valve interstitial cells (VICs) are essential for valvular pathogenesis. However, the transcriptional profiles and cellular functions of human aortic VICs (hAVICs) and mitral VICs (hMVICs) have not been directly compared. We performed NimbleGen gene expression profiling analyses of hAVICs and hMVICs. Seventy-eight known genes were differentially expressed between hAVICs and hMVICs. Higher expression of NKX2-5, TBX15, OGN, OMD, and CDKN1C and lower expression of TBX5, MMP1, and PCDH10 were found in hAVICs compared to hMVICs. The differences in these genes, excepting OGN and OMD, remained in rheumatic VICs. We also compared cell proliferation, migration, and response to mineralization medium. hMVICs proliferated more quickly but showed more calcium deposition and alkaline phosphatase activity than hAVICs after culture in mineralization medium, indicating that hMVICs were more susceptible to in vitro calcification. Our findings reveal differences in the transcription profiles and cellular functions of hAVICs and hMVICs.