Toggle Main Menu Toggle Search

Open Access padlockePrints

Proteinases involved in matrix turnover during cartilage and bone breakdown

Lookup NU author(s): Emeritus Professor Tim Cawston, Professor David YoungORCiD



The joint is a discrete unit that consists of cartilage, bone, tendon and ligaments. These tissues are all composed of an extracellular matrix made of collagens, proteoglycans and specialised glycoproteins that are actively synthesised, precisely assembled and subsequently degraded by the resident connective tissue cells. A balance is maintained between matrix synthesis and degradation in healthy adult tissues. Different classes of proteinases play a part in connective tissue turnover in which active proteinases can cleave matrix protein during resorption, although the proteinase that predominates varies between different tissues and diseases. The metalloproteinases are potent enzymes that, once activated, degrade connective tissue and are inhibited by tissue inhibitors of metalloproteinases (TIMPs); the balance between active matrix metalloproteinases and TIMPs determines, in many tissues, the extent of extracellular matrix degradation. The serine proteinases are involved in the initiation of activation cascades and some, such as elastase, can directly degrade the matrix. Cysteine proteinases are responsible for the breakdown of collagen in bone following the removal of the osteoid layer and the attachment of osteoclasts to the exposed bone surface. Various growth factors increase the synthesis of matrix and proteinase inhibitors, whereas cytokines ( alone or in combination) can inhibit matrix synthesis and stimulate proteinase production and matrix destruction.

Publication metadata

Author(s): Cawston TE, Young DA

Publication type: Review

Publication status: Published

Journal: Cell and Tissue Research

Year: 2010

Volume: 339

Issue: 1

Pages: 221-235

ISSN (print): 0302-766X

ISSN (electronic): 1432-0878

Publisher: SPRINGER


DOI: 10.1007/s00441-009-0887-6