Tenascin and
fibronectin are extracellular matrix
glycoproteins which can interact with cells and alter their capacity to adhere, migrate and proliferate. In contrast with
fibronectin,
tenascin has a restricted distribution in normal skin, but is induced during epidermal proliferation, and in wound healing. Because
acne involves hyperproliferation of ductal keratinocytes, and
rupture of the duct may occur during
inflammation, the distribution of
tenascin and
fibronectin was investigated in
acne lesions, and also in
acne keloids. Biopsies obtained from patients attending the
acne clinics were cryostat-sectioned and stained with
tenascin antiserum. The extent of
tenascin staining in the dermis around the pilosebaceous unit was measured.
Tenascin was continually expressed around normal control pilosebaceous ducts; it was maximal around the acroinfundibulum, extending 20.83 +/- 9.32 microns (n = 14) into the dermis, compared with staining around the infrainfundibulum (11.88 +/- 3.70 microns, n = 14). This was not significantly different from staining around normal pilosebaceous ducts obtained from
acne patients. In non-inflamed lesions
tenascin staining increased significantly around the infrainfundibulum to 76.88 +/- 29.97 microns (n = 12), compared with this region in the normal follicles. The staining around the acroinfundibulum did not change significantly. Around inflamed lesions the whole of the dermis was positive for
tenascin. No changes were detected in the staining pattern for
fibronectin, which stained the whole dermis in all the sections tested. The
keloid samples stained strongly for both extracellular matrix
glycoproteins. Thus, increased
tenascin expression appears to be associated with the development of
acne lesions.(ABSTRACT TRUNCATED AT 250 WORDS)