title: Cloning, expression, and type II collagenolytic activity of matrix metalloproteinase-13 from human osteoarthritic cartilage.
abstract: Proteolysis of triple-helical collagen is an important step in the progression toward irreversible tissue damage in osteoarthritis. Earlier work on the expression of enzymes in cartilage suggested that collagenase-1 (MMP-1) contributes to the process. Degenerate reverse transcription polymerase chain reaction experiments, Northern blot analysis, and direct immunodetection have now provided evidence that collagenase-3 (MMP-13), an enzyme recently cloned from human breast carcinoma, is expressed by chondrocytes in human osteoarthritic cartilage. Variable levels of MMP-13 and MMP-1 in cartilage was significantly induced at both the message and protein levels by interleukin-1 alpha. Recombinant MMP-13 cleaved type II collagen to give characteristic 3/4 and 1/4 fragments; however, MMP-13 turned over type II collagen at least 10 times faster than MMP-1. Experiments with intact type II collagen as well as a synthetic peptide suggested that MMP-13 cleaved type II collagen at the same bond as MMP-1, but this was then followed by a secondary cleavage that removed three amino acids from the 1/4 fragment amino terminus. The expression of MMP-13 in osteoarthritic cartilage and its activity against type II collagen suggest that the enzyme plays a significant role in cartilage collagen degradation, and must consequently form part of a complex target for proposed therapeutic interventions based on collagenase inhibition.
authors.affiliation: Central Research Division, Pfizer Inc., Groton, Connecticut 06340, USA.
authors.forename: P G
authors.initials: PG
authors.lastname: Mitchell
authors.forename: H A
authors.initials: HA
authors.lastname: Magna
authors.forename: L M
authors.initials: LM
authors.lastname: Reeves
authors.forename: L L
authors.initials: LL
authors.lastname: Lopresti-Morrow
authors.forename: S A
authors.initials: SA
authors.lastname: Yocum
authors.forename: P J
authors.initials: PJ
authors.lastname: Rosner
authors.forename: K F
authors.initials: KF
authors.lastname: Geoghegan
authors.forename: J E
authors.initials: JE
authors.lastname: Hambor
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002356:Cartilage / Q000201:enzymology*; D003001:Cloning, Molecular; D003094:Collagen / Q000378:metabolism*; D017364:Collagenases / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D053509:Matrix Metalloproteinase 13; D008969:Molecular Sequence Data; D010003:Osteoarthritis / Q000201:enzymology*; D016133:Polymerase Chain Reaction; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013379:Substrate Specificity
chemical_list: D003094:Collagen; D017364:Collagenases; C507079:MMP13 protein, human; D053509:Matrix Metalloproteinase 13