[Morphologic and functional characterization of human aortic endothelium. III. Growth in culture and colony formation at low seeding density]. / Morfologicheskie i funtsional'nye osobennosti éndoteliia aorty cheloveka. III. Rost v kul'ture i formirovanie kolonii pri nizkoi plotnosti posadki.

In human aortic endothelial cell (HAEC) cultures, obtained separately from aortic zones of low (LP) and high (HP) probability of atherosclerosis, proliferative characteristics of cells and HAEC ability to form colonies at clonal seeding density were studied. It has been found that the population doubling time is significantly higher in endothelial cell (EC) cultures from HP-zones, compared to that in cultures from LP-zones of the same vessels. In cultures from both LP- and HP-zones only a few percent of EC had a proliferative potential enough to form cell colonies. The number of formed colonies was always lower in EC cultures from HP-zones, and decreased depending on atherosclerotic lesions and cell donor age. The obtained data suggest that the decline of EC proliferative potential, mostly in HP-zones (even without visible signs of atherosclerotic lesions) is due to a decrease in the number of cells with a high mitotic activity, i.e. "cambial" cells.

[Induction of cell adhesion molecules, E-selectin, VCAM-1 and ICAM-1, in a co-culture of human endothelial and smooth muscle cells]. / Induktsiia molekul kletochnoi adgezii, E-selektina, VCAM-1 i ICAM-1 v sovmestnoi kul'ture éndotelial'nykh i gladkomyshechnykh kletok cheloveka.

Using immunofluorescence and flow cytometry, we studied the surface expression of cell adhesion molecules, E-selectin, VCAM-1 and ICAM-1, in human umbilical vein endothelial cells (HUVEC) co-cultured with human aortic intimal smooth muscle cells (SMC). It was found that inactivated HUVEC constitutively expressed only ICAM-1. After 3-4 h of co-culturing with SMC in the Transwell system we observed the appearance of E-selectin and VCAM-1, and the increase of ICAM-1 content on the cell surface. In all the cases, the maximum expression of these molecules (85-100% of positively stained cells) was detected within 18-24 h after co-culturing. Similar effect was exerted by SMC-conditioned culture medium, whose action well compared with that of a direct addition of interleukin-1 to EC at a concentration of 5-10 u/ml. The obtained data suggest that the cytokines secreted by SMC may participate in the regulation of endothelial cell adhesion molecule expression, and influence cell accumulation in sites of inflammation, immune disorders, etc.

Use of enzyme label for quantitative evaluation of liposome adhesion on cell surface: studies with J774 macrophage monolayers.

A method for quantitation of cell surface-bound liposomes utilizing J774 macrophage monolayers is developed. Surface-bound biotinyl-containing and 125I-labeled liposomes were quantified with avidin-peroxidase in an ELISA-like assay. Peroxidase substrate absorbance values were recalculated into the absolute amount of liposomal lipid using a special calibration plot. Total liposome uptake by macrophages was determined following the binding of 125I radioactivity. The approach suggested allows quantitative evaluation of the changes in the content of surface-adhered liposomes during their interaction with cells in vitro.

[Interaction of liposomes with a varying lipid composition with hepatocytes in vitro]. / Vzaimodeistvie liposom s razlichnym lipidnym sostavom s kletkami gepatotsitov in vitro.

Interaction of liposomes from egg lecithin, phospholipids and gangliosides of rat liver with rat hepatocyte monolayers was investigated. It was shown that liposomes from phospho- and glycolipids of the liver were bound by rat hepatocytes to a far greater degree than lecithin liposomes. Liver gangliosides increased active endocytosis of liposomes by hepatocytes. Preincubation of hepatocytes with gangliosides reduced the binding of phosphoglycolipid liposomes by those cells.