Aging and matrix biology.

This introduction to a theme issue of Pathologie Biologie on the extracellular matrix starts with a brief overview of the advances made over the last few years and of the increasing specialization they have resulted in. A review is then presented of cell-matrix interactions, with emphasis on those mediated by the elastin-laminin receptor during physiologic processes and during aging and age-related diseases. The activated human lymphocyte expressing the elastin-laminin receptor is used as an example. When exposed to low levels of elastin peptides (kappa-elastin, 75 kappa D, 1-10 micrograms/ml, i.e., 1.4 to 14.10(-8)M), this receptor mediates increases in cell growth and in the production of serine-elastase. Levels of about 100 micrograms/ml are associated with cell death due to necrosis and to apoptosis. This example illustrates the key role played by epigenetic phenomena in aging of cells and tissues.