Periostin activates distinct modules of inflammation and itching downstream of the type 2 inflammation pathway.

Atopic dermatitis (AD) is a chronic relapsing skin disease accompanied by recurrent itching. Although type 2 inflammation is dominant in allergic skin inflammation, it is not fully understood how non-type 2 inflammation co-exists with type 2 inflammation or how type 2 inflammation causes itching. We have recently established the FADS mouse, a mouse model of AD. In FADS mice, either genetic disruption or pharmacological inhibition of periostin, a downstream molecule of type 2 inflammation, inhibits NF-κB activation in keratinocytes, leading to downregulating eczema, epidermal hyperplasia, and infiltration of neutrophils, without regulating the enhanced type 2 inflammation. Moreover, inhibition of periostin blocks spontaneous firing of superficial dorsal horn neurons followed by a decrease in scratching behaviors due to itching. Taken together, periostin links NF-κB-mediated inflammation with type 2 inflammation and promotes itching in allergic skin inflammation, suggesting that periostin is a promising therapeutic target for AD.

The FADS mouse: A novel mouse model of atopic keratoconjunctivitis.

BACKGROUND: Atopic keratoconjunctivitis (AKC) is a chronic allergic conjunctival disease. However, a mouse model of AKC to investigate the underlying mechanism of the therapeutic agents and estimate their efficacy has not been established. We recently generated mice in which Ikk2 is specifically deleted in facial skin fibroblasts and found that these mice spontaneously develop atopic dermatitis (AD)-like facial skin inflammation and scratching behaviors; thus, we named them facial AD with scratching (FADS) mice. OBJECTIVE: We sought to evaluate whether the ocular lesions that FADS mice spontaneously develop are similar to those of patients with AKC and to estimate the efficacy of topical treatments with tacrolimus and betamethasone for FADS mice by using tear periostin, a novel biomarker for allergic conjunctival disease. METHODS: FADS mice, in which Ikk2 is deleted in dermal fibroblasts, were generated by crossing female Ikk2Flox/Flox mice to male Nestincre; Ikk2Flox/+ mice. We conducted histologic analysis of the ocular lesions in FADS mice. Furthermore, we measured periostin in the tears collected from FADS mice untreated or treated with tacrolimus or betamethasone. RESULTS: The FADS mice exhibited severe blepharitis and scratch behaviors for their faces. In these mice, corneal epithelium and stroma showed hyperplasia and infiltration of eosinophils, mast cells, and TH2/TC2 cells. Periostin was significantly expressed in the lesions and tear periostin was upregulated. Betamethasone showed more suppressive effects than did tacrolimus on severe corneal lesions and increased tear periostin level. CONCLUSIONS: The FADS mouse is a novel mouse model of AKC and is useful to examine the therapeutic effects of anti-AKC agents.

Differential proteome analysis in adolescent idiopathic scoliosis patients with thoracolumbar/lumbar curvatures.

BACKGROUND: Although the pathogenesis of adolescent idiopathic scoliosis (AIS) remains unclear, there are little evidences of the pathogenesis in patients with thoracolumbar/lumbar AIS. The purpose of this study was to identify proteins or proteomes that may be causally related to the pathogenesis of AIS with structured thoracolumbar/lumbar curvature using two-dimensional fluorescence difference gel electrophoresis (2D-DIGE). METHODS: A total of 20 control volunteers and 61 AIS in patients with thoracolumbar/lumbar curvature were included. First, the plasma samples of each five AIS with pure thoracolumbar/lumbar curvature and control samples were subjected to 2D-DIGE analysis. Protein spots that were expressed differently by the AIS and control groups were selected and identified by nanoscale liquid chromatography-tandem mass spectrometry (nanoLC-MS/MS) analysis. To characterize the differently-expressed proteins in AIS patients, we performed functional pathway analysis using the Protein ANalysis THrough Evolutionary Relationships (PANTHER) system. Additionally, the proteins were compared between control and AIS using western blotting. Lastly, prospectively collected 15 control and 41 AIS with thoracolumbar/lumbar curvature samples were compared to the differentially expressed proteins. RESULTS: A total of 3862 ± 137 spots were detected, of which 11 spots met the criteria when compared with controls. Nine proteins were identified by nanoLC-MS/MS. Functional analysis showed the association of the proteins in AIS patients with blood coagulation using the PANTHER system. Of the proteins, vitamin D binding protein (DBP) significantly correlated with Cobb angle in thoracolumbar/lumbar curvatures. DBP expression of the prospectively collected AIS samples were significantly higher than those of controls (P < 0.05). CONCLUSIONS: This study suggests that DBP and several coagulation-related proteins may play a role in the pathogenesis of AIS. DBP appears to be a marker of severity of AIS with thoracolumbar/lumbar curvature.

Establishment of a Mouse Model of Atopic Dermatitis by Deleting Ikk2 in Dermal Fibroblasts.

Atopic dermatitis is a chronic inflammatory skin disease with persistent pruritus. To clarify its molecular mechanism, it is important to establish a mouse model similar to the phenotypes of atopic dermatitis patients, particularly in exhibiting scratching behavior. Ikk2, a component of the IκB kinase complex, exerts pro-inflammatory responses, whereas its deficiency in keratinocytes paradoxically causes skin inflammation. In this study, we sought to generate a mouse model exhibiting skin inflammation by which dermal fibroblasts lack Ikk2 expression and evaluate whether cutaneous inflammatory phenotypes are similar to those of atopic dermatitis patients. To generate Ikk2-deficient mice (Nestincre;Ikk2FL/FL) in which Ikk2 is deleted in dermal fibroblasts, we crossed female Ikk2FL/FL mice to male Nestincre;Ikk2FL/+mice. These mice spontaneously developed skin inflammation limited to the face, with the appearance of Ikk2-deficient fibroblasts in the facial skin. These mice showed phenotypes similar to those of atopic dermatitis patients, including scratching behaviors, which are resistant to immunosuppressive or molecularly targeted drugs. These findings suggest that the Nestincre;Ikk2FL/FL mouse is an atopic dermatitis model that will be useful in clarifying atopic dermatitis pathogenesis and in developing a novel therapeutic agent for atopic dermatitis symptoms.

PEA3 cooperates with c-Jun in regulation of HER2/neu transcription.

HER2/neu overexpressing breast tumors exhibit an increase in polyomavirus enhancer activator 3 (PEA3) expression. We examined the relationship between HER2/neu transcriptional activation and PEA3 in cooperation with c-Jun. HER2/neu promoter activity was decreased by deleting PEA3 binding site, and was downregulated when the PEA3 binding site was mutated. PEA3 and c-Jun each weakly enhanced luciferase expression of the HER2/neu promoter. However, the HER2/neu promoter response to PEA3 was considerably enhanced by c-Jun. Thus, we examined the interaction of PEA3 with c-Jun by the two-hybrid system, the transcriptional activity of PEA3 was specifically enhanced by c-Jun. When PEA3, c-Jun and coactivator p300 were cotransfected in MCF7 cells, the transcriptional activity of HER2/neu was increased by up to 20-fold. PEA3 and c-Jun-induced transcription of HER2/neu promoter was repressed by cotransfection of the dominant negative of p300. These results suggest that PEA3 and c-Jun stimulated synergistically the HER2/neu gene transcription with p300.