Involvement of nuclear factor of activated T cells in granulocyte–macrophage colony‐stimulating factor production in canine keratinocytes stimulated with a cysteine protease

Abstract

The results suggest that GM-CSF production mediated by the cysteine protease is regulated not only by NFAT but also by unknown signalling pathways in canine keratinocytes.

Canine progenitor epidermal keratinocytes express various inflammatory markers, including interleukin‐8 and CD40, which are affected by certain antibiotics

“…Based on what has been published to date, they are adherent, proliferative, capable of differentiation, express similar protein markers to primary keratinocytes and have been used to recreate stratum corneum in vitro. 8,25,26,[28][29][30][31][32] Using both ELISA and immunocytochemistry, we could not detect any MHC II protein in CPEKs. This protein has been detected in primary and immortalized keratinocytes of several species, including mice, rats and humans, [13][14][15]33,34 and in canine skin biopsies, where its expression was increased in cutaneous lesions.…”

“…We chose this cell line because of its phenotypic characteristics similar to those of primary keratinocytes. Based on what has been published to date, they are adherent, proliferative, capable of differentiation, express similar protein markers to primary keratinocytes and have been used to recreate stratum corneum in vitro …”

“…The mRNA of TNFα, a very powerful pro‐inflammatory cytokine, has previously been detected in CPEKs, but only after stimulation with atopic allergens . These various cytokines have also been found, although usually only at the mRNA level, in skin lesions or skin cell lines, including canine samples, stimulated with allergenic agents . Interestingly, other studies showed that the expression of several of these cytokines increased in immune cells from allergic patients or sensitized mice exposed to allergenic chemicals ex vivo .…”

A review of the roles of keratinocyte‐derived cytokines and chemokines in the pathogenesis of atopic dermatitis in humans and dogs

“…The GM‐CSF production was suppressed by addition of a cysteine protease inhibitor, suggesting that its production was most likely mediated via PAR‐2 by Der f 1, which is one of the major allergens and a cysteine protease . Similar to Der f 1, papain, a naturally derived cysteine protease, also induced GM‐CSF production with translocation of nuclear factor of activated T cells (NFAT) in CPEK, and production was partially inhibited by ciclosporin . These results suggest that GM‐CSF production in CPEK activated via PAR‐2 may be regulated not only by NFAT, but also by another transcription factor, such as nuclear factor‐kB (NF‐kB) or activator protein‐1 (AP‐1).…”

“…93 Similar to Der f 1, papain, a naturally derived cysteine protease, also induced GM-CSF production with translocation of nuclear factor of activated T cells (NFAT) in CPEK, and production was partially inhibited by ciclosporin. 94 These results suggest that GM-CSF production in CPEK activated via PAR-2 may be regulated not only by NFAT, but also by another transcription factor, such as nuclear factor-kB (NF-kB) or activator protein-1 (AP-1). A recent study demonstrated that IL-17A, a typical Th17 cytokine, also induced the transcription of gm-csf in CPEK.…”