Type I collagen fibers account for 90% of the organic matrix of bone. The degradation of this collagen is a major event during bone resorption, but its mechanism is unknown. A series of data obtained in biological models strongly suggests that the recently discovered cysteine proteinase cathepsin K plays a key role in bone resorption. Little is known, however, about the actual action of catheps...

Objective. To analyze the in vivo compartmental expression of collagenases 1 and 3 (MMP-1 and MMP13) in the Hartley guinea pig model of spontaneously occurring osteoarthritis (OA) for the purpose of elucidating their roles in the pathogenesis of OA. Methods. Competitive reverse transcriptionpolymerase chain reaction (RT-PCR) and immunohistochemistry quantification of messenger RNA (mRNA) and pr...

INTRODUCTION Traumatic injury to cartilage is often associated with acutely elevated levels of pro-inflammatory cytokines, such as interleukin-1 (IL-1), that promote the accumulation and activation of degradative enzymes, including collagenases (MMP-1, MMP-13) and aggrecanases (ADAMTS-4, ADAMTS-5) in the synovial joint [1]. These enzymes prompt degradation of major extracellular matrix componen...

Salmonella penetrates the basement membrane of intestinal epithelial cells into deeper tissues, in which process extracellular matrix proteases should be required. Hypothesizing that the proteases might be provided by host cells, we investigated the changes of expression of urokinase type plasminogen activator(u-PA), plasminogen activator inhibitor-1(PAI-1), and collagenases in epithelial cells...

The purpose of this study was to examine the role of interstitial collagenases, members of the family of matrix metalloproteinases, in the development of pulmonary fibrosis. The activity, levels and molecular forms of collagenases (matrix metalloproteinases (MMP)-1, -8 and -13), gelatinase B (MM P-9) and its main endogenous inhibitor, tissue inhibitor of metalloproteinase-1 (TIMP-1) were assess...

During tissue-invasive events, migrating cells penetrate type I collagen-rich interstitial tissues by mobilizing undefined proteolytic enzymes. To screen for members of the matrix metalloproteinase (MMP) family that mediate collagen-invasive activity, an in vitro model system was developed wherein MDCK cells were stably transfected to overexpress each of ten different MMPs that have been linked...