Protein kinase C (PKC) plays a key role in the transduction of extracellular signals across the membrane. The PKC family consists of six unique genes that give rise to at least seven different PKC subtypes which form two groups, the classical subtypes (a, bI, bII, g) and a novel group of at least three subtypes (d, e, z) (for review see reference [10]). The high degree of conservation and the differential distribution of these proteins suggest that they perform distinct functions in vivo [10,11,13].
As reported by Fisher ct al.
[1], PKC is present in human epidermis. Other studies have demonstrated that the enzyme plays a regulatory role in epidermal proliferation and differentiation (for review see reference [4]). Recent studies comparing skin of psoriatic lesions with healthy skin showed differences in activity and distribution of PKC [5,6].
In the present study, we investigated the localization of gene expression, encoding for the PKC subtypes a, bI, and blI in the trunk epidermis of healthy volunteers (n = 5) and psoriatic patients (n = 7) by in situ hybridization. The skin samples were immediately snapfrozen in liquid nitrogen and stored at -70 ~ Sections (5 gm) were cut on a cryostat at -24 ~ air-dried for at least 1 h, and fixed in 4% paraformaldehyde/phosphatebuffered saIine. Oligonucleotide probes for human PKC bI and bII (anti-sense and sense probe, see Kubo et al. [9]) were purchased from Oncogene Science (Manhasset, NY, USA), and for rat PKC a (anti-sense probe, see Knopf et al. [7]) from Clontech (Palo Alto, Calif., USA).