BACKGROUND: Clinical studies have demonstrated that 50% of individuals with chronic renal disease (CRD) die of cardiovascular causes, including advanced calcific arterial and valvular disease; however, the mechanisms of accelerated calcification in CRD remain obscure, and no therapies can prevent disease progression. We recently demonstrated in vivo that inflammation triggers cardiovascular calcification. In vitro evidence also indicates that elastin degradation products may promote osteogenesis. Here, we used genetically modified mice and molecular imaging to test the hypothesis in vivo that cathepsin S (catS), a potent elastolytic proteinase, accelerates calcification in atherosclerotic mice with CRD induced by 5/6 nephrectomy. METHODS AND RESULTS: Apolipoprotein-deficient (apoE(-/-))/catS(+/+) (n=24) and apoE(-/-)/catS(-/-) (n=24) mice were assigned to CRD and control groups. CRD mice had significantly higher serum phosphate, creatinine, and cystatin C levels than those without CRD. To visualize catS activity and osteogenesis in vivo, we coadministered catS-activatable and calcification-targeted molecular imaging agents 10 weeks after nephrectomy. Imaging coregistered increased catS and osteogenic activities in the CRD apoE(-/-)/catS(+/+) cohort, whereas CRD apoE(-/-)/catS(-/-) mice exhibited less calcification. Quantitative histology demonstrated greater catS-associated elastin fragmentation and calcification in CRD apoE(-/-)/catS(+/+) than CRD apoE(-/-)/catS(-/-) aortas and aortic valves. Notably, catS deletion did not cause compensatory increases in RNA levels of other elastolytic cathepsins or matrix metalloproteinases. Elastin peptide and recombinant catS significantly increased calcification in smooth muscle cells in vitro, a process further amplified in phosphate-enriched culture medium. CONCLUSIONS: The present study provides direct in vivo evidence that catS-induced elastolysis accelerates arterial and aortic valve calcification in CRD, providing new insight into the pathophysiology of cardiovascular calcification.
BACKGROUND: Clinical studies have demonstrated that 50% of individuals with chronic renal disease (CRD) die of cardiovascular causes, including advanced calcific arterial and valvular disease; however, the mechanisms of accelerated calcification in CRD remain obscure, and no therapies can prevent disease progression. We recently demonstrated in vivo that inflammation triggers cardiovascular calcification. In vitro evidence also indicates that elastin degradation products may promote osteogenesis. Here, we used genetically modified mice and molecular imaging to test the hypothesis in vivo that cathepsin S (catS), a potent elastolytic proteinase, accelerates calcification in atheroscleroticmice with CRD induced by 5/6 nephrectomy. METHODS AND RESULTS:Apolipoprotein-deficient (apoE(-/-))/catS(+/+) (n=24) and apoE(-/-)/catS(-/-) (n=24) mice were assigned to CRD and control groups. CRDmice had significantly higher serum phosphate, creatinine, and cystatin C levels than those without CRD. To visualize catS activity and osteogenesis in vivo, we coadministered catS-activatable and calcification-targeted molecular imaging agents 10 weeks after nephrectomy. Imaging coregistered increased catS and osteogenic activities in the CRDapoE(-/-)/catS(+/+) cohort, whereas CRDapoE(-/-)/catS(-/-) mice exhibited less calcification. Quantitative histology demonstrated greater catS-associated elastin fragmentation and calcification in CRDapoE(-/-)/catS(+/+) than CRDapoE(-/-)/catS(-/-) aortas and aortic valves. Notably, catS deletion did not cause compensatory increases in RNA levels of other elastolytic cathepsins or matrix metalloproteinases. Elastin peptide and recombinant catS significantly increased calcification in smooth muscle cells in vitro, a process further amplified in phosphate-enriched culture medium. CONCLUSIONS: The present study provides direct in vivo evidence that catS-induced elastolysis accelerates arterial and aortic valve calcification in CRD, providing new insight into the pathophysiology of cardiovascular calcification.
Authors: Ziad A Massy; Ognen Ivanovski; Thao Nguyen-Khoa; Jesus Angulo; Dorota Szumilak; Nadya Mothu; Olivier Phan; Michel Daudon; Bernard Lacour; Tilman B Drüeke; Martin S Muntzel Journal: J Am Soc Nephrol Date: 2004-11-24 Impact factor: 10.121
Authors: Caroline S Fox; Martin G Larson; Ramachandran S Vasan; Chao-Yu Guo; Helen Parise; Daniel Levy; Eric P Leip; Christopher J O'donnell; Ralph B D'Agostino; Emelia J Benjamin Journal: J Am Soc Nephrol Date: 2005-12-28 Impact factor: 10.121
Authors: Elena Aikawa; Peter Whittaker; Mark Farber; Karen Mendelson; Robert F Padera; Masanori Aikawa; Frederick J Schoen Journal: Circulation Date: 2006-03-14 Impact factor: 29.690
Authors: M Aikawa; E Rabkin; Y Okada; S J Voglic; S K Clinton; C E Brinckerhoff; G K Sukhova; P Libby Journal: Circulation Date: 1998-06-23 Impact factor: 29.690
Authors: Jimmy J Chan; L Adrienne Cupples; Douglas P Kiel; Christopher J O'Donnell; Udo Hoffmann; Elizabeth J Samelson Journal: J Bone Miner Res Date: 2015-05-06 Impact factor: 6.741
Authors: Julia Collin; Mario Gössl; Yoshiki Matsuo; Rebecca R Cilluffo; Andreas J Flammer; Darrell Loeffler; Ryan J Lennon; Robert D Simari; Daniel B Spoon; Raimund Erbel; Lilach O Lerman; Sundeep Khosla; Amir Lerman Journal: Int J Cardiol Date: 2014-11-26 Impact factor: 4.164