Aortic Valve Endothelial Cells Undergo Transforming Growth Factor-β-Mediated and Non-Transforming Growth Factor-β-Mediated Transdifferentiation in Vitro

摘要: Cardiac valves arise from endocardial cushions, specialized regions of the developing heart that are formed by an endothelial-to-mesenchymal cell transdifferentiation. Whether and to what extent this transdifferentiation is retained in mature unknown. Herein we show endothelial cells can transdifferentiate a mesenchymal phenotype. Using induction α-smooth muscle actin (α-SMA), established marker for process, two distinct pathways were identified clonally derived populations isolated ovine aortic valve leaflets. α-SMA expression was induced culturing clonal medium containing either transforming growth factor-β or low levels serum no basic fibroblast factor. Cells express exhibited markedly increased migration response platelet-derived factor-BB, consistent with A population differentiated co-expressed CD31, marker, along α-SMA, as seen double-label immunofluorescence. Similarly, co-expression markers detected subpopulation frozen sections valves, suggesting may occur vivo. Hence, valvular described here provide powerful vitro model dissecting molecular events regulate endothelium.