title: Selective inhibition of matrix metalloproteinase-13 increases collagen content of established mouse atherosclerosis.
abstract: OBJECTIVE
  Evidence has linked collagen loss with the onset of acute coronary events. This study tested the hypothesis that selective matrix metalloproteinase-13 (MMP-13) collagenase inhibition increases collagen content in already established and nascent mouse atheromas.
  
  
  RESULTS
  In vitro and in situ experiments documented the selectivity and efficacy of an orally available MMP-13 inhibitor (MMP13i-A). In vivo observations monitored macrophage accumulation and MMP-13 activity using molecular imaging. After 10 weeks of MMP13i-A treatment, apolipoprotein E-deficient mice with evolving or established lesions exhibited reduced MMP-13 activity without affecting macrophage content, measured either by intravital microscopy or fluorescence reflectance imaging. Histological analysis indicated that MMP13-iA did not affect plaque size or macrophage or smooth muscle cell accumulation. Administration of MMP13i-A to mice with evolving or established atheromas substantially increased plaque interstitial collagen content in the intima and locally in the fibrous cap, compared with vehicle-treated controls. Analysis of collagen revealed thicker collagen fibers within the plaques of treated groups.
  
  
  CONCLUSIONS
  Pharmacological MMP-13 inhibition yields collagen accumulation in plaques (a feature associated in humans with resistance to rupture), even in established plaques. This study, of considerable clinical relevance, furnishes new mechanistic insight into regulation of the plaque's extracellular matrix and validates molecular imaging for studying plaque biology.
authors: Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
authors: Thibaut
authors: T
authors: Quillard
authors: Yevgenia
authors: Y
authors: Tesmenitsky
authors: Kevin
authors: K
authors: Croce
authors: Richard
authors: R
authors: Travers
authors: Eugenia
authors: E
authors: Shvartz
authors: Konstantinos C
authors: KC
authors: Koskinas
authors: Galina K
authors: GK
authors: Sukhova
authors: Elena
authors: E
authors: Aikawa
authors: Masanori
authors: M
authors: Aikawa
authors: Peter
authors: P
authors: Libby
mesh_terms: D000818:Animals; D001057:Apolipoproteins E / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D050197:Atherosclerosis / Q000378:metabolism* / Q000473:pathology; D002340:Carotid Artery Diseases / Q000378:metabolism / Q000473:pathology; D003094:Collagen / Q000378:metabolism*; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006801:Humans; D008264:Macrophages / Q000187:drug effects / Q000473:pathology; D008297:Male; D053509:Matrix Metalloproteinase 13 / Q000187:drug effects* / Q000378:metabolism; D061965:Matrix Metalloproteinase Inhibitors; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000473:pathology; D058226:Plaque, Atherosclerotic / Q000378:metabolism / Q000473:pathology
chemical_list: D001057:Apolipoproteins E; D004791:Enzyme Inhibitors; D061965:Matrix Metalloproteinase Inhibitors; D003094:Collagen; D053509:Matrix Metalloproteinase 13