Minimally modified low-density lipoprotein induces monocyte chemotactic protein-1 expression in vivo and a novel model for monocyte adhesion to arterial intima.
OBJECTIVE
To test whether minimally modified low-density lipoprotein (MM-LDL) can stimulate the arterial cells expressing MCP-1 in vivo and thus induce monocyte adherence to endothelium.


METHODS
An animal model was constructed to study the function of MM-LDL in vivo. MM-LDL (600 micrograms/ml) was perfused into a segment of the femoral artery of rabbits (both ends of which were occluded with removable ligatures). After exposure to MM-LDL for 2 h, the arterial segments were taken out 6 or 18 h later. The arteries were subjected to in situ hybridization with 35S-labeled antisense monocyte chemotactic protein-1 (MCP-1) RNA probe and processed for scanning electron microscopy.


RESULTS
The expression of MCP-1 mRNA of the arterial endothelial cells and smooth muscle cells were increased by 60% and 90% 6 h after perfusion and had a 3.2 folds and 1.6 folds increase 18 h after perfusion respectively as compared with control (arteries perfused with saline). There was also apparent monocyte adherence to the endothelium observed by scanning electron microscopy.


CONCLUSIONS
MM-LDL can stimulate vascular cells in expressing MCP-1 mRNA and enhance monocyte adherence to endothelium in vivo.
Xiao
D
D
Department of Internal Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China. danhua@163.net
Wang
Z
Z
She
M
M
D000818:Animals; D002448:Cell Adhesion; D018932:Chemokine CCL2 / Q000096:biosynthesis* / Q000235:genetics; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D005263:Femoral Artery / Q000378:metabolism / Q000648:ultrastructure; D008077:Lipoproteins, LDL / Q000494:pharmacology*; D008297:Male; D009000:Monocytes / Q000166:cytology*; D009131:Muscle, Smooth, Vascular / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011817:Rabbits
D018932:Chemokine CCL2; D008077:Lipoproteins, LDL; D012333:RNA, Messenger