Structure and function of basement membranes.

The importance of basement membranes in development and adult tissue function has been inferred from a number of observations. Cells migrate along basement membranes during development, basement membranes are required for the polarization of cells in both the embryo and the adult, and basement membranes serve as substrates for cell adhesion and migration during wound healing and nerve regeneration. The importance of basement membranes in adult tissue function has been directly demonstrated by the genetic diseases caused by mutations in the genes for structural basement membrane components. Examples of such diseases are Alport syndrome and junctional epidermolysis bullosa. Recently, defects in the major laminin variant in muscle, merosin, has been shown to be correlated with muscular dystrophies in man and animals. We are using the dystrophic mutant mouse dy, which lacks laminin-2, to analyze the function of laminin-2 in different tissues. Studies of laminin defects in animals and humans are expected to give new information on the function of basement membrane in general and on laminin in particular. Such information may give directions for future diagnosis and treatment of diseases involving basement membranes.