Cited 36 times since 2008 (2.3 per year) source: EuropePMC Arteriosclerosis, thrombosis, and vascular biology, Volume 29, Issue 2, 18 3 2008, Pages 188-194 Leukocyte cathepsin S is a potent regulator of both cell and matrix turnover in advanced atherosclerosis. de Nooijer R, Bot I, von der Thüsen JH, Leeuwenburgh MA, Overkleeft HS, Kraaijeveld AO, Dorland R, van Santbrink PJ, van Heiningen SH, Westra MM, Kovanen PT, Jukema JW, van der Wall EE, van Berkel TJ, Shi GP, Biessen EA
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.
