Construction of Three Dimensional Vascular Wall Model :Effects of low density lipoprotein and oxidized low density lipoprotein on endothelial cells and smooth muscle cells

Park, Ho Chul; Park, Jae Kyung; Chung, Jae Sam

Abstract

To study the biology of the endothelium and media under conditions that mimic the architecture of the vascular wall and the effects of low density lipoprotein(LDL) and oxidized lipoprotein(ox-LDL), three dimensional vascular wall model was constructed in vitro. In the vascular wall model, endothelial cells(EC) were grown on a collagen lattice containing multilayer of smooth muscle cells(SMC) and endothelial cell-free portion was made by a cloning ring on the culture disc. The availability of this vascular wall model promptly us to examine the extent LDL and ox-LDL affect ECs and SMCs when these cells were maintained with or without each other in coculture. The results were as follows; 1) Morphologic characteristics of three dimensional vascular wall model Artificial vascular wall was a whitish, non-transparent membrane. Outer boundaries and the zone of no ECs were thicker than that of central portion. By light microscope imaging, luminal surface was EC monolayer, and SMCs and collagen fibers were distributed between the PET membrane and EC monolayer. SMCs and collagen fibers were mainly located near the PET membrane. Venous SMCs were densely infiltrated as compared to arterial SMCs. By scanning electron microscopy, EC monolayer was clearly shown. 2) The effects of LDL and oxidized LDL on ECs and SMCs in artificial vascular wall (1) The effects of LDL Collagen fibers are infiltrated just beneath EC monolayer in venous SMCs-EC coculture model. In the zone of no EC, marked proliferation and synthesis of collagen fibers were noted. (2) The effects of ox-LDL Injured EC monolayer were clearly shown in both venous and arterial SMCs-EC coculture model. On high power field light microscopic examination, collagen fibers were exposed outside to the luminal surface and were pendendicularly arranged, and looked like as ciliary projection. Artificial wall of these experimental model were thicker than that of control, and proliferation of SMCs and collagen synthesis were increased than those of control and LDL experiment groups. On scanning electromicroscopic examination, ECs were more slender and cell-to-cell contact was loosened. As a conclusion, this vascular wall model is to be good experimental model for vascular research. And LDL and ox-LDL have toxic effects on vascular EC layer and stimulate proliferation of SMCs and collagen synthesis in vitro three dimensionally constructed vascular wall model.