Deletion of tenascin-C gene exacerbates atherosclerosis and induces intraplaque hemorrhage in Apo-E-deficient mice.
OBJECTIVE
Tenascin-C (TNC), a matricellular protein, is up-regulated in atherosclerotic plaques. We investigated whether the deletion of TNC gene affects the development of atherosclerosis in a murine model.


METHODS
TNC-/-/apo E-/- mice were generated and used for atherosclerosis studies. We compared these results to those observed in control groups of apo E-/- mice.


RESULTS
The en face analysis of aortic area showed that the mean aortic lesion area of the double knockout (KO) mice was significantly higher than that of control mice at different times after feeding of atherogenic diet; the accumulation of lesional macrophages and lipids was significantly higher. Analysis of cell adhesion molecules revealed that vascular cell adhesion molecule-1 (VCAM-1), but not intercellular adhesion molecule-1, was up-regulated 1 week after feeding of atherogenic diet in the double KO mouse as compared to apo E-/- mouse. Cell culture studies revealed that the expression of VCAM-1 in endothelial cells isolated from the double KO mouse is more sensitive to the tumor necrosis factor α stimulation than the cells isolated from apo E-/- mice. Cell adhesion studies showed that the adherence of RAW monocytic cells to the endothelial cells was significantly enhanced in the cultured endothelial cells from the TNC gene-deleted cells. Following the prolonged feeding of an atherogenic diet (28-30 weeks), the aortic and carotid atherosclerotic lesions frequently demonstrated large grossly visible areas of intraplaque hemorrhage in the double KO mice compared to control.


CONCLUSIONS
These data unveil a protective role for TNC in atherosclerosis and suggest that TNC signaling may have the potential to reduce atherosclerosis, in part by modulating VCAM-1 expression.
Oppenheimer Atherosclerosis Research Center and the Division of Cardiology, Cedars Sinai Heart Institute, Los Angeles, CA 90048, USA.
Lai
L
Wang
Wei
W
Wang
Prediman K
PK
Shah
Lei
L
Song
Mingjie
M
Yang
Behrooz G
BG
Sharifi
D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D001057:Apolipoproteins E / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism; D050197:Atherosclerosis / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D002339:Carotid Arteries / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D002448:Cell Adhesion / Q000187:drug effects; D002478:Cells, Cultured; D004041:Dietary Fats / Q000008:administration & dosage; D004195:Disease Models, Animal; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism; D005260:Female; D017353:Gene Deletion; D005838:Genotype; D006470:Hemorrhage / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D008074:Lipoproteins / Q000097:blood; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009000:Monocytes / Q000187:drug effects / Q000378:metabolism; D058226:Plaque, Atherosclerotic / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D019063:Tenascin / Q000235:genetics* / Q000378:metabolism; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism
D001057:Apolipoproteins E; D004041:Dietary Fats; D008074:Lipoproteins; D019063:Tenascin; D019010:Vascular Cell Adhesion Molecule-1