Local cortisol activation is involved in EGF-induced immunosuppression

e90

Abstracts from the 41st Annual Meeting / Journal of Dermatological Science 86 (2017) e1–e95

of chronic CHS responses using two common haptens, oxazolone and dinitrochlorobenzene (DNCB). Compared to the acute phase, repeated application of both oxazolone and DNCB equally elicited an early-type hypersensitivity response in the chronic phase. Although both haptens locally induced a mixed Th1- and Th2-type of gene expression, oxazolone- and DNCB-treated skin revealed a skewing IL-4 and IL-17 response, respectively. The frequencies of multi-cytokine producing T cells in regional draining lymph nodes were declined by repeated hapten treatment, suggesting that effector response in the chronic phase largely occurred within the skins. Interestingly, while there was a similar proportion of dermal dendritic cells (DCs) in the DNCB-treated lesion compared to the uninflamed dermis, oxazolone-treated skin harbored an abundant infiltration of CD11b+ DCs and profound reduction of EpCAM+ Langerhans cells in the dermis. Our results indicate that chronic exposure to the different types of hapten drives a distinct cytokine milieu possibly by utilizing particular DC subsets in the skin. http://dx.doi.org/10.1016/j.jdermsci.2017.02.262 L-05[O1-48] Local cortisol activation is involved in EGF-induced immunosuppression Sayaka Matsumura 1,∗ , Mika Terao 2 , Satoshi Itami 2 , Ichiro Katayama 1 1 Department of Dermatology, Osaka University Graduate School of Medicine, Japan 2 Department of Regenerative Dermatology, Osaka University Graduate School of Medicine, Japan Major effects of EGFR signalling pathway on keratinocyte are cell proliferation, cell differentiation, and wound healing. In addition to these effects, immunosuppressive effect of EGF has been reported. Upregulation of EGFR and its ligands were found in chronic inflammatory skin disorders including atopic dermatitis. Protective role for EGF in atopic dermatitis has also been reported. However precise mechanism of immunosuppression by EGF is not well understood. In this study, we clarified the involvement of increased local cortisol activation by 11␤-HSD1 in EGF-induced immunosuppression in keratinocytes. We found that EGF up-regulates the expression of 11␤hydroxysteroid dehydrogenase 1 (11␤-HSD1) and supernatant cortisol level dose dependently in keratinocytes. 11␤-HSD1 is the enzyme that catalyses the conversion of hormonally inactive cortisone into active cortisol in cells. As in other cells, EGF significantly decreased TNF␣-induced IL-6 expression by RT-PCR and ELISA in keratinocytes. Similarly, 11␤-HSD1 overexpression significantly decreased TNF␣-induced IL-6 expression. On the other hand, blockade of 11␤-HSD1 by either siRNA or 11␤-HSD1 inhibitor significantly increased TNF␣-induced IL-6 expression. Finally, we evaluated the role of 11␤-HSD1 in immunosuppression by EGF. Blockage of 11␤-HSD1 by either siRNA or 11␤-HSD1 inhibitor reversed EGF-induced immunosuppression in keratinocytes. Taken together of these results, we conclude that increased local cortisol activation by 11␤HSD1 is involved in EGF-induced immunosuppression in keratinocytes. As 11␤-HSD1 in keratinocytes is associated with inflammation and cell proliferation, this mechanism might be associated with adverse skin reaction observed in patients treated with EGF receptor inhibitors.

http://dx.doi.org/10.1016/j.jdermsci.2017.02.263

L-06[O1-49] Dermokine ␤/␥ deficiency causes the selective impairment of epidermal barrier function in mice Akira Utsunomiya 1,∗ , Takenao Chino 1 , Atsushi Tokuriki 1 , Vu Huy Loung 1 , Noritaka Oyama 1 , Kiyoshi Higashi 2 , Koichi Saito 2 , Minoru Hasegawa 1 1

Department of Dermatology, University of Fukui, Fukui, Japan 2 Environmental Health Science Laboratory, Sumitomo Chemical Co., Ltd., Osaka, Japan Background: Dermokine (DMKN) family members consist of four splicing variants (␣, ␤, ␥, and ␦) and each of these is thought to play an important role in inflammatory skin disorders, such as atopic dermatitis and psoriasis. Both ␤ and ␥ isoforms are expressed specifically in the upper epidermis, although their in vivo functions remain enigmatic. Objective: The purpose of this study was to investigate the pathophysiological impact of DMKN ␤/␥ in skin by using mice genetically deficient in these two molecules. Method: We analyzed phenotypic differences in the skin morphology, pathology, and microstructure between DMKN ␤/␥ knockout (KO) mice and wild type littermates. In vivo epidermal permeability was evaluated by trans-epidermal water loss (TEWL) and dye diffusion assays. Results: The DMKN ␤/␥ KO mice did not show lethality at any developmental stages, and impairment of embryonic/postnatal growth and organ development. However, their skin morphology exhibited obvious scales and deep wrinkling by postnatal day 8, and spontaneously became normal thereafter. At the early neonatal stage, the KO mice showed significant increase of the TEWL level, but not dye diffusion. Conclusion: DMKN ␤/␥ deficiency in mice caused a subtle skin phenotype with transient hyperkeratosis, wrinkle formation, and persisted epidermal impermeability of water during the early neonatal stage. Our data suggests the possible involvement of postnatal stage-specific action of DMKN ␤/␥ in the corneo-epidermal barrier function. http://dx.doi.org/10.1016/j.jdermsci.2017.02.264 L-07[O2-57] Ambrisentan moderately, but not significantly, improved impaired wound healing by bleomycin treatment in mice Masato Ishikawa ∗ , Toshiyuki Yamamoto Department of Dermatology, Fukushima Medical University, Japan Bleomycin-induced scleroderma model is an established model for human scleroderma, and mice pretreated with bleomycin showed significant delay in cutaneous wound healing. Bosentan is a dual endothelin receptor antagonist, which has been cited as useful in the prevention but not healing of cutaneous ulcers. We sought to evaluate the effect of the selective endothelin receptor type A antagonist ambrisentan (AMB) on cutaneous ulcers in patients with SSc, using impaired wound healing murine model. After inducing dermal sclerosis by local bleomycin treatment, wound was made by 6 mm punch excision. We measured wound area which determined digital image analysis and expressed as percentage of the wound area immediately after punch excision, and gave AMB or phosphate-buffered saline (PBS) by mouth to wound closure. Mea-