A hierarchy of endothelial colony-forming cell activity displayed by bovine corneal endothelial cells.

PURPOSE To test the hypothesis that the robust expansion of bovine corneal endothelial cells (BCECs) in vitro is due to the presence of individual endothelial cells with various levels of proliferative potential. METHODS BCECs and bovine vascular endothelial cells (ECs) derived from aorta, coronary artery, and pulmonary artery were cultivated in optimized medium. These cell populations were confirmed by morphologic features, functional assays, and gene expression profiles. Moreover, ECs were plated in a single-cell clonogenic assay to evaluate colony-forming ability. RESULTS Both corneal and vascular ECs were confirmed to be pure populations of endothelium uncontaminated with hematopoietic cells. A complete hierarchy of endothelial colony-forming cells (ECFCs) was identified in BCECs by a single-cell clonogenic assay. The distribution of the various types of ECFCs was similar to the control ECs removed from the systemic vessels. CONCLUSIONS Cultured BCECs display clonal proliferative properties similar to those of vascular ECs.