Long-term culture of human mucosal microvascular endothelial cells and angiogenesis in vitro

Human mucosal microvascular endothelial cells (HMMECs) were isolated and cultured from nasal inferior turbinates. These cells can be maintained for up to 30 passages over 10 months, as long as human umbilical vein endothelial cells (HUVECs), using dish-coated collagen and MCDB 107 medium supplemented with 10% fetal bovine serum and 75 micrograms/ml of crude endothelial cell growth factor prepared from bovine brain. These cells readily formed capillary-like structures when cultivated on dish-coated collagen or collagen gels as compared with HUVECs. The collagenase activities of conditioned medium from HMMEC culture on collagen gels were considerably higher in tumor conditioned medium while those from HUVECs were undetectable. The capillary-like structure in the collagen gel and the collagenase activities of conditioned medium were periodically changed during long-term cultivation of HMMECs. A good correlation between the two was observed. These results, suggest that there are phenotypic differences between HMMECs and HUVECs and that collagenase plays an important role in angiogenesis. These cultured HMMECs could serve as a valuable experimental model for determining mucosal pathogenesis in the nasal and paranasal sinus regions.