title: Degradation of cartilage proteoglycan by human leukocyte granule neutral proteases--a model of joint injury. I. Penetration of enzyme into rabbit articular cartilage and release of 35SO4-labeled material from the tissue.
abstract: The present work was undertaken to explore the effect of two purified neutral proteases derived from human peripheral blood polymorphonuclear leukocytes (PMN) on articular cartilage as a model of joint injury. Human leukocyte elastase and chymotrypsin-like enzyme, purified by affinity chromatography, released 32SO4 from labeled rabbit articular cartilage slices in vitro. Release of isotope was initially delayed, suggesting that either a lag in enzyme penetration occurs or that size of degradation fragments is a limiting factor in diffusion of label out of the tissue. The release of 35SO4 was inhibited by preincubation of elastase and chymotrypsin-like enzyme with human alpha 1-anti-trypsin, or with their specific chloromethyl ketone inactivators, and the action of elastase was also inhibited by a monospecific antiserum to PMN elastase, freed of major serum proteinase inhibitors. Immunohistochemical staining procedures revealed the presence of PMN elastase inside the matrix of cartilage slices after a 20-min exposure of tissue to either the pure enzyme or crude PMN granule extract. Serum alpha 1-antitrypsin failed to penetrate into the cartilage slices under identical in vitro conditions. In association with the results reported in the accompanying paper, these findings suggest a model of cartilage matrix degradation by PMN neutral proteases in which local protease-antiprotease imbalance, coupled with different rates of penetration of protease and antiprotease into target tissue, plays a key role in accounting for matrix damage.
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000187:drug effects / Q000378:metabolism*; D002918:Chymotrypsin / Q000302:isolation & purification / Q000494:pharmacology; D003594:Cytoplasmic Granules / Q000378:metabolism*; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006025:Glycosaminoglycans / Q000378:metabolism*; D006801:Humans; D007106:Immune Sera; D007592:Joint Diseases / Q000378:metabolism*; D007700:Kinetics; D007962:Leukocytes / Q000201:enzymology / Q000648:ultrastructure*; D009842:Oligopeptides / Q000494:pharmacology; D010196:Pancreatic Elastase / Q000302:isolation & purification / Q000494:pharmacology; D010447:Peptide Hydrolases / Q000378:metabolism*; D010649:Phenylalanine / Q000031:analogs & derivatives; D011509:Proteoglycans / Q000378:metabolism*; D011817:Rabbits; D013462:Sulfur Radioisotopes; D000515:alpha 1-Antitrypsin / Q000378:metabolism / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D006025:Glycosaminoglycans; D007106:Immune Sera; D009842:Oligopeptides; D011509:Proteoglycans; D013462:Sulfur Radioisotopes; D000515:alpha 1-Antitrypsin; D010649:Phenylalanine; D010447:Peptide Hydrolases; D002918:Chymotrypsin; D010196:Pancreatic Elastase