2-STAGE ISOLATION PROCEDURE FOR OBTAINING HOMOGENOUS POPULATIONS OF MICROVASCULAR ENDOTHELIAL AND MESOTHELIAL CELLS FROM HUMAN OMENTUM

The human omentum is a highly vascularized tissue often advocated as a source of human microvascular endothelial (HOME) cells. The omentum a lso contains mesothelial (MESO) cells and isolation protocols publishe d to date do not describe a separation of the two cell populations, Us ing a two-stage collagenase digestion procedure, homogenous population s of HOME and MESO cells are obtained from the same omental tissue sam ple. HOME and MESO cells are both simple squamous epithelial cells and consequently are often difficult to discriminate between based on mor phology and reactivity with many of the conventional endothelial and m esothelial cell markers. Both HOME and MESO cells form typical cobbles tone, contact-inhibited monolayers, metabolize DiI-Ac-LDL, and are imm unoreactive to von Willebrand Factor and Ulex europeaus I lectin. Howe ver, MESO cells are distinguishable from HOME cells based upon their e xpression of cytokeratins. Moreover, HOME cells and not MESO cells for m capillary-like structures when cultured on Matrigel. It appears that HOME and MESO cells share many phenotypic properties, but are disting uishable from one another based upon a comprehensive panel of endothel ial and mesothelial markers, Both cell types should be useful for stud ying the biology and pathology of the human microvasculature in vitro. (C) 1997 Academic Press.