title: Protease activity enhances production of thymic stromal lymphopoietin and basophil accumulation in flaky tail mice.
abstract: Epidermal barrier abnormality due to filaggrin deficiency is an important predisposing factor in the development of atopic dermatitis (AD). In addition, the expression of thymic stromal lymphopoietin (TSLP) in keratinocytes (KCs), induced by barrier disruption, can promote type 2 helper T-cell polarization. Protease activity, including protease-activated receptor-2 (PAR-2), is also known to be involved in epidermal barrier function in AD. However, to our knowledge, the relationship between protease activity and filaggrin deficiency from the perspective of AD has not been elucidated. Flaky tail (Flg(ft)) mice, known to have a mutation in the filaggrin gene, were used to assess the role of protease in KCs in the steady state and the mite-induced AD-like skin inflammation model. In the steady state, the expression and activity levels of endogenous proteases, kallikreins 5, 7, and 14, in the skin and TSLP were higher in Flg(ft) than in control mice. In addition, activation of PAR-2 by its agonist induced the production of TSLP in KCs of Flg(ft) mice, which was abrogated by a newly developed PAR-2 antagonist. Application of the PAR-2 antagonist improved symptoms and basophil accumulation in Flg(ft) mice treated with mite extracts. These results suggest that possibly through the PAR-2 activation in KCs, filaggrin deficiency induces TSLP production and basophil accumulation, which play important roles in the establishment of AD.
authors: Department of Dermatology, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors: Catharina S
authors: CS
authors: Moniaga
authors: Se Kyoo
authors: SK
authors: Jeong
authors: Gyohei
authors: G
authors: Egawa
authors: Saeko
authors: S
authors: Nakajima
authors: Mariko
authors: M
authors: Hara-Chikuma
authors: Jeong Eun
authors: JE
authors: Jeon
authors: Seung Hun
authors: SH
authors: Lee
authors: Toshihiko
authors: T
authors: Hibino
authors: Yoshiki
authors: Y
authors: Miyachi
authors: Kenji
authors: K
authors: Kabashima
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D001491:Basophils / Q000378:metabolism*; D016207:Cytokines / Q000096:biosynthesis*; D003876:Dermatitis, Atopic / Q000469:parasitology / Q000473:pathology; D005260:Female; D000091344:Filaggrin Proteins; D006639:Histidine / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007381:Intermediate Filament Proteins / Q000235:genetics*; D007610:Kallikreins / Q000378:metabolism; D015603:Keratinocytes / Q000201:enzymology / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D008925:Mites / Q000502:physiology; D010447:Peptide Hydrolases / Q000378:metabolism*; D044464:Receptor, PAR-2 / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism; D012867:Skin / Q000469:parasitology / Q000473:pathology; D013623:Tail; D000094632:Thymic Stromal Lymphopoietin
chemical_list: D000596:Amino Acids; D016207:Cytokines; D000091344:Filaggrin Proteins; D007381:Intermediate Filament Proteins; D044464:Receptor, PAR-2; D006639:Histidine; D010447:Peptide Hydrolases; D007610:Kallikreins; D000094632:Thymic Stromal Lymphopoietin