LOCALIZATION OF TRANSGLUTAMINASE-1 MESSENGER-RNA IN NORMAL AND PSORIATIC EPIDERMIS BY NONRADIOACTIVE INSITU HYBRIDIZATION

We examined the expression of the transglutaminase 1 (TGase1) gene in frozen sections of normal and psoriatic epidermis by means of non-radioactive in situ hybridization with digoxigenin-labelled cRNA probes. TGase1 mRNA was expressed in the granular layer of normal epidermis, regardless of ortho- or hyperkeratosis. However, in psoriatic epidermis, TGase1 mRNA was detected in the suprabasal spinous layer, but not in the subcorneal layer. These results indicate that TGase1 gene expression is limited to the last stage of keratinization in normal epidermis and this regulation is disturbed in psoriasis.