Infiltration/accumulation of low density lipoproteins in endothelial/smooth muscle cell co-culture preparations with different modes

Using different endothelial/smooth muscle cell co-culture modes to simulate the intimal structure of blood vessels, the water filtration rate and the infiltration/accumulation of LDL of the cultured cell layers were studied. The three cell culture modes of the study were: i) endothelial cell monolayer (EC/Φ); ii) endothelial cells directly co-cultured on the smooth muscle cell monolayer (EC-SMC); iii) endothelial cells and smooth muscle cells cultured on different sides of a Millicell- CM membrane (EC/SMC). It was found that under the same condition, the water filtration rate was the lowest for EC/SMC mode and the highest for EC/Φ mode, while the infiltration/ accumulation of DiI-LDLs was the lowest in the EC/Φ mode and the highest in the EC-SMC mode. It was also found that the values of DiI-LDL infiltration/accumulation in the cultured cell layers increased with increasing the water filtration rate, vw. The results from the in vitro model study therefore suggest that the infiltration/ accumulation of the lipids within the arterial wall is positively correlated with concentration polarization of atherogenic lipids, and the integrity of the endothelium plays an important role in the penetration and accumulation of atherogenic lipids in blood vessel walls.