Abstract
OBJECTIVE: A dysbalance of proteases and their inhibitors is instrumental in remodeling of atherosclerotic plaques. One of the proteases implicated in matrix degradation is cathepsin-S (CatS). To address its role in advanced lesion composition, we generated chimeric LDLr(-/-) mice deficient in leukocyte CatS by transplantation with CatS(-/-)xLDLr(-/-) or with LDLr(-/-) bone marrow and administered a high-fat diet.
METHODS AND RESULTS: No difference in aortic root lesion size could be detected between CatS(+/+) and CatS(-/-) chimeras. However, leukocyte CatS deficiency markedly changed plaque morphology and led to a dramatic reduction in necrotic core area by 77% and an abundance of large foam cells. Plaques of CatS(-/-) chimeras contained 17% more macrophages, 62% less SMCs, and 33% less intimal collagen. The latter two could be explained by a reduced number of elastic lamina fractures. Moreover, macrophage apoptosis was reduced by 60% with CatS deficiency. In vitro, CatS was found to be involved in cholesterol metabolism and in macrophage apoptosis in a collagen and fibronectin matrix.
CONCLUSIONS: Leukocyte CatS deficiency results in considerably altered plaque morphology, with smaller necrotic cores, reduced apoptosis, and decreased SMC content and collagen deposition and may thus be critical in plaque stability.
| Original language | English |
|---|---|
| Pages (from-to) | 188-94 |
| Number of pages | 7 |
| Journal | Arteriosclerosis, Thrombosis and Vascular Biology |
| Volume | 29 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Feb 2009 |
Keywords
- Animals
- Aorta
- Apoptosis
- Atherosclerosis
- Bone Marrow Transplantation
- Cathepsins
- Cell Movement
- Cell Proliferation
- Cells, Cultured
- Cholesterol
- Collagen
- Diet, Atherogenic
- Disease Models, Animal
- Elastic Tissue
- Extracellular Matrix
- Female
- Foam Cells
- Leukocytes
- Macrophages, Peritoneal
- Mice
- Mice, Knockout
- Myocytes, Smooth Muscle
- Necrosis
- Protease Inhibitors
- Receptors, LDL
- Transplantation Chimera