Cell-matrix interactions in aging: role of receptors and matricryptins.
Extracellular matrix (ECM) has been a central topic in aging research for several years. Cell-matrix interactions extend the interest in this topic both for normal tissue homeostatic regulation as well as for its dysregulation in age-related diseases. A relatively new extension of this ever-increasing field of aging research concerns the recognition of the original biological activities exhibited by proteolytic fragments of matrix macromolecules. A number of such matricryptins were recently identified, some of them endowed with harmful effects for tissue function. Some of the breakdown products exert a positive feedback effect by upregulating the biosynthesis of the original macromolecule synthesis and/or the expression of degrading enzymes. This results in vicious circles which might well be involved in tissue aging. The examples detailed in this review concern fibronectin (FN) and elastin. A number of fibronectin fragments (Fn-fr) were shown to exhibit diverse activities including increasing tissue degradation, inflammation and tumor progression. Elastin degradation products acting as agonists on the elastin-laminin receptor can trigger harmful effects such as up-regulation of proteases and free radical production. Both macromolecules are at the center of autoamplifying vicious circles of potential importance for age-dependent modification of tissue function.
Labat-Robert
J
J
Laboratoire d'Ophtalmologie, Hôtel-Dieu, 1 place du parvis Notre Dame, 75181 Paris Cedex 04, France. lrobert5@wanadoo.fr
D000375:Aging / Q000502:physiology*; D000818:Animals; D002450:Cell Communication / Q000502:physiology*; D016326:Extracellular Matrix Proteins / Q000502:physiology*; D006801:Humans; D039081:Integrin alpha5beta1 / Q000502:physiology*; D011956:Receptors, Cell Surface / Q000502:physiology; D016024:Receptors, Cytoadhesin / Q000502:physiology
D016326:Extracellular Matrix Proteins; D039081:Integrin alpha5beta1; D011956:Receptors, Cell Surface; D016024:Receptors, Cytoadhesin; C477138:elastin-laminin receptor, rat