Objectives:
To develop and validate a 3D
in-vitro
model of atherosclerosis that enables direct interaction between various cell types and/or extracellular matrix.
Methods and Results:
Type I collagen (0.75 mg/mL) was mixed with human artery smooth muscle cells (SMCs; 6x10
5
cells/mL), medium, and water. Human coronary artery endothelial cells (HCAECs; 10
5
/cm
2
) were plated on top of the collagen gels and activated with oxidized low density lipoprotein cholesterol (LDL-C). Monocytes (THP-1 cells; 10
5
/cm
2
) were then added on top of the HCAECs. Immunofluorescence showed the expression of VE-cadherin by HCAECs (A, B) and α-smooth muscle actin by SMCs (A). Green-labelled LDL-C particles were accumulated in the subendothelial space, as well as in the cytoplasm of HCAECs and SMCs (C). Activated monocytes were attached to HCAECs and found in the subendothelial area (G-I). Both HCAECs and SMCs released IL-1β, IL-6, IL-8, PDGF-BB, TGF-ß1, and VEGF. Scanning and transmission electron microscopy showed the HCAECs monolayer forming gap junctions and the SMCs (D-F) and transmigrating monocytes within the collagen matrix (G-I).
Conclusions:
In this work, we presented a novel, easily reproducible and functional
in-vitro
experimental model of atherosclerosis that has the potential to enable
in-vitro
sophisticated molecular and drug development studies.