Integrins and cell signaling in chondrocytes.
Integrins are adhesion receptor heterodimers that transmit information from the extracellular matrix (ECM) to the cell through activation of cell signaling pathways. Chondrocytes express several members of the integrin family including alpha5beta1 which is the primary chondrocyte receptor for fibronectin. Cell signaling mediated through integrins regulates several chondrocyte functions including differentiation, matrix remodeling, responses to mechanical stimulation and cell survival. Integrin-mediated activation of members of the mitogen-activated protein kinase family likely plays a key role in transmitting signals regulating chondrocyte gene expression. Upstream mediators of mitogen-activated protein kinase (MAP kinase) activation include focal adhesion kinase (FAK) and proline-rich tyrosine kinase 2 (pyk2) which are both expressed by chondrocytes. A better understanding of chondrocyte integrin signaling is needed to define the mechanisms by which the ECM regulates chondrocyte function.
Loeser
Richard F
RF
Department of Internal Medicine, Section of Rheumatology, Rush Medical College of Rush-Presbyterian-St. Luke's Medical Center, Chicago, IL 60612, USA. rloeser@rush.edu
D002358:Cartilage, Articular / Q000378:metabolism*; D019902:Chondrocytes / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D006133:Growth Substances / Q000378:metabolism; D006801:Humans; D016023:Integrins / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*
D016207:Cytokines; D006133:Growth Substances; D016023:Integrins