INTRACELLULAR DETECTION OF LAMININ ALPHA(2) CHAIN IN SKIN BY ELECTRON-MICROSCOPY IMMUNOCYTOCHEMISTRY - COMPARISON BETWEEN NORMAL AND LAMININ ALPHA(2) CHAIN DEFICIENT SUBJECTS

The aim of this study is to localize the a, laminin chain in normal hu man skin. The methods used were immune-gold cytochemistry on cryo-ultr amicrotomy sections and thin-section-fracture-label, together with ele ctron microscopy observation. Results were compared with light microsc opy peroxidase immune-staining. Both normal skin samples and skin biop sies from laminin cc, chain deficient congenital muscular dystrophy af fected patients were studied. The results show that, in normal skin, t he laminin, chain is spread throughout the cytoplasm of basal keratino cytes, while it appears associated with desmosomal tonofilaments in th e spinous and granular epidermal layers, in skin samples from dystroph ic patients the laminin a, chain was not detectable. These data sugges t that the function of the laminin alpha(2) chain is different in the epidermis as compared to that in muscle and peripheral nerve, where it is localized in the basement membrane. (C) 1997 Elsevier Science B.V.