Mayumi Komine

Interleukin-12 p40 gene (IL12B) 3'-untranslated region polymorphism is associated with susceptibility to atopic dermatitis and psoriasis vulgaris.

Interleukin-12 (IL-12) is believed to play an important role in inducing Th1-type cytokine profiles. Atopic dermatitis (AD) and psoriasis vulgaris (PsV) are considered to be Th2 and Th1 type disease, respectively. The IL-12 p40 subunit gene (IL12B) is located at chromosome 5q31-33 and linkage findings of AD on 5q31 were reported. Recently single nucleotide polymorphism (SNP) (1188A/C) of IL12B has been reported. In function, it has been reported that this SNP is associated with IL12B mRNA expression levels. To learn whether this SNP is associated with susceptibility to AD or PsV, we investigated the genotype and allele frequencies of the SNP in AD patients, in PsV patients and in controls, examining 164 AD patients, 143 PsV patients and 100 healthy individuals in Japanese population. Genotyping was performed using the polymerase chain reaction-restriction fragment length polymorphism method. The A allele was decreased in AD patients (40.9%, p = 0.031) and increased in PsV patients (60.1%, p = 0.035) compared with controls (50.5%). This suggests that IL12B SNP is associated with susceptibility to AD and PsV, presumably by affecting the Th1/Th2 balance.

Serum macrophage-derived chemokine (MDC) levels are closely related with the disease activity of atopic dermatitis

Atopic dermatitis (AD) is a chronic and relapsing inflammatory skin disease characterized by the predominant infiltration of T cells, eosinophils and macrophages in lesional skin. Recently, macrophage‐derived chemokine (MDC)/CCL22, a CC chemokine, was identified as a selective chemoattractant for CC chemokine receptor 4 (CCR4)‐expressing cells, in addition to thymus and activation‐regulated chemokine (TARC). We have previously reported that serum TARC levels correlate with the severity of AD. In this report, we investigated the participation of MDC in AD. First, we measured serum MDC levels in 45 patients with AD, 25 patients with psoriasis vulgaris and 25 healthy controls. Serum MDC levels in AD patients were significantly higher than those in healthy controls and psoriasis patients. Furthermore, the increases in serum MDC levels in AD patients were greater in the severely affected group than in the moderate or mild groups. We compared serum MDC levels in 11 AD patients, before and after treatment, and observed a significant decrease after treatment. Moreover, the serum MDC levels significantly correlated with the Scoring AD (SCORAD) index, serum soluble (s) E‐selectin levels, serum soluble interleukin‐2 receptor (sIL‐2R) levels, serum TARC levels and eosinophil numbers in peripheral blood. Our study strongly suggests that serum MDC levels have a notable correlation with disease activity and that MDC, as well as the CC chemokine TARC, may be involved in the pathogenesis of AD.

Novel Mechanism of Steroid Action in Skin through Glucocorticoid Receptor Monomers

ABSTRACT Glucocorticoids (GCs), important regulators of epidermal growth, differentiation, and homeostasis, are used extensively in the treatment of skin diseases. Using keratin gene expression as a paradigm of epidermal physiology and pathology, we have developed a model system to study the molecular mechanism of GCs action in skin. Here we describe a novel mechanism of suppression of transcription by the glucocorticoid receptor (GR) that represents an example of customizing a device for transcriptional regulation to target a specific group of genes within the target tissue, in our case, epidermis. We have shown that GCs repress the expression of the basal-cell-specific keratins K5 and K14 and disease-associated keratins K6, K16, and K17 but not the differentiation-specific keratins K3 and K10 or the simple epithelium-specific keratins K8, K18, and K19. We have identified the negative recognition elements (nGREs) in all five regulated keratin gene promoters. Detailed footprinting revealed that the function of nGREs is to instruct the GR to bind as four monomers. Furthermore, using cotransfection and antisense technology we have found that, unlike SRC-1 and GRIP-1, which are not involved in the GR complex that suppresses keratin genes, histone acetyltransferase and CBP are. In addition, we have found that GR, independently from GREs, blocks the induction of keratin gene expression by AP1. We conclude that GR suppresses keratin gene expression through two independent mechanisms: directly, through interactions of keratin nGREs with four GR monomers, as well as indirectly, by blocking the AP1 induction of keratin gene expression.

Significant elevation of serum levels of eotaxin-3/CCL26, but not of eotaxin-2/CCL24, in patients with atopic dermatitis: serum eotaxin-3/CCL26 levels reflect the disease activity of atopic dermatitis

Atopic dermatitis (AD) is a chronic and relapsing inflammatory skin disease characterized by the predominant infiltration of T cells, eosinophils and macrophages in lesional skin. Recently, eotaxin‐2/CCL24 and eotaxin‐3/CCL26 were identified as CC chemokines that signal exclusively via the CCR3 receptor and have eosinophil‐selective chemoattractant activity, as does eotaxin/CCL11. We previously reported that serum levels of thymus and activation‐regulated chemokine (TARC)/CCL17 and macrophage‐derived chemokine (MDC)/CCL22 were correlated with the severity of AD. In this report, we investigated the participation of eotaxin‐2/CCL24 and eotaxin‐3/CCL26 in AD, first measuring the serum levels of eotaxin‐2/CCL24 and eotaxin‐3/CCL26 in 30 patients with AD, 20 patients with psoriasis vulgaris and 20 healthy controls. The serum levels of eotaxin‐3/CCL26 (but not eotaxin‐2/CCL24) were significantly higher in patients with AD than in either healthy controls or patients with psoriasis vulgaris; furthermore, the eotaxin‐3/CCL26 levels in patients with moderate and severe AD were significantly higher than eotaxin‐3/CCL26 levels in patients with mild AD. The serum eotaxin‐3/CCL26 levels tended to decrease after treatment, but there was no significant difference between groups. Moreover, the serum eotaxin‐3/CCL26 levels were significantly correlated with the serum TARC/CCL17 and MDC/CCL22 levels, eosinophil numbers in peripheral blood and the scoring AD (SCORAD) index. Our study strongly suggests that serum levels of eotaxin‐3/CCL26, but not of eotaxin‐2/CCL24, have a notable correlation with disease activity of AD and that eotaxin‐3/CCL26, as well as TARC/CCL17 and MDC/CCL22, may be involved in the pathogenesis of AD.

Interleukin-4 and interleukin-13 enhance CCL26 production in a human keratinocyte cell line, HaCaT cells

Eotaxin‐2/CCL24 and eotaxin‐3/CCL26 are CC chemokines and their receptor, CC chemokine receptor 3 is preferentially expressed on eosinophils. It was reported that vascular endothelial cells and dermal fibroblasts produced CCL26. However, the regulation of CCL24 and CCL26 production in keratinocytes has not been well documented. We investigated the expression and production of CCL24 and CCL26 in the human keratinocyte cell line, HaCaT cells. Reverse transcription and polymerase chain reaction was performed using these cells and Enzyme‐linked immunosorbent assay was carried out using supernatant of these cells. The production of CCL24 in HaCaT cells was slightly enhanced by IL‐4 and that of CCL26 was strongly enhanced by IL‐4 and IL‐13. Furthermore, TNF‐α generated a synergistic effect on IL‐4 enhanced CCL26 production. Dexamethasone, IFN‐γ and the p38 mitogen‐activated protein kinase inhibitor SB202190 inhibited IL‐4 enhanced CCL26 production. IL‐4 enhanced production of CCL26 was inhibited by leflunomide and JAK inhibitor 1, but not by JAK3 inhibitor, which indicates that it is mediated by JAK1‐STAT6‐dependent pathway. This result also strongly suggests the involvement of the type 2 IL‐4 receptor in IL‐4 enhanced production of CCL26. These results suggest that keratinocytes are involved in the migration of CC chemokine receptor 3 positive cells such as eosinophils in a Th2‐dominant situation like atopic dermatitis.

Role of Matrix Metalloproteinases in Photoaging and Photocarcinogenesis

Matrix metalloproteinases (MMPs) are zinc-containing endopeptidases with an extensive range of substrate specificities. Collectively, these enzymes are able to degrade various components of extracellular matrix (ECM) proteins. Based on their structure and substrate specificity, they can be categorized into five main subgroups, namely (1) collagenases (MMP-1, MMP-8 and MMP-13); (2) gelatinases (MMP-2 and MMP-9); (3) stromelysins (MMP-3, MMP-10 and MMP-11); (4) matrilysins (MMP-7 and MMP-26); and (5) membrane-type (MT) MMPs (MMP-14, MMP-15, and MMP-16). The alterations made to the ECM by MMPs might contribute in skin wrinkling, a characteristic of premature skin aging. In photocarcinogenesis, degradation of ECM is the initial step towards tumor cell invasion, to invade both the basement membrane and the surrounding stroma that mainly comprises fibrillar collagens. Additionally, MMPs are involved in angiogenesis, which promotes cancer cell growth and migration. In this review, we focus on the present knowledge about premature skin aging and skin cancers such as basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma, with our main focus on members of the MMP family and their functions.

Polymorphisms of vitamin D receptor gene in Japanese patients with psoriasis vulgaris

We examined polymorphisms of vitamin D receptor (VDR) gene in Japanese patients with psoriasis vulgaris (PsV). We also studied the association between VDR gene polymorphisms and the response to vitamin D (VD) topical treatment in psoriatic patients. FokI, BsmI, ApaI and TaqI genotypes were determined by restriction fragment patterns in patients (n = 115) and controls (n = 69). In addition, 54 psoriatic patients were divided into two groups in terms of their response to VD (tacalcitol) topical treatment: non-responsive (n = 30) and responsive (n = 24) patients. The frequencies of B allele and t allele were lower in patients than in controls (9 vs. 19%: p < 0.01, 7 vs. 14%: p < 0.05, respectively). In regard to response to VD treatment, F allele was lower in non-responsive patients than in controls (47 vs. 64%, p < 0.05). We show that polymorphisms of VDR gene are associated with Japanese patients with PsV. Allelic variance in the VDR gene or other genes in linkage disequilibrium with this gene might predispose to the development of PsV.

Both IL-4 and IL-13 inhibit the TNF-α and IFN-γ enhanced MDC production in a human keratinocyte cell line, HaCaT cells

Abstract Background: Macrophage-derived chemokine (MDC) is a Th2 type chemokine and its receptor CC chemokine receptor 4 (CCR4) is preferentially expressed on Th2 cells. Recent reports demonstrated that MDC is expressed not only by macrophages, dendritic cells and lymphocytes, but also by cultured human keratinocytes (KCs). However, the regulation of MDC production in KCs by various cytokines has not been well documented. Objective: In this study, we investigated how Th1/Th2 cytokines regulate MDC production in a human KC cell line, HaCaT cells. Methods: HaCaT cells were cultured with or without various cytokines for 24 h and RT-PCR was performed using these cells to evaluate MDC mRNA levels. ELISA was carried out using supernatant of HaCaT cells to calculate secreted MDC protein levels. Results: MDC mRNA was weakly expressed in HaCaT cells, and upon stimulation with TNF-α or IFN-γ, MDC expression was strongly upregulated. The supernatant MDC levels when stimulated with TNF-α or IFN-γ were significantly higher than those without stimulation, and were synergistically increased when stimulated with a combination of TNF-α and IFN-γ. Both interleukin-4 (IL-4) and IL-13 inhibited TNF-α and IFN-γ enhanced MDC production in HaCaT cells in a dose-dependent manner. Conclusion: Th2-type cytokines IL-4 and IL-13 downregulate the production of MDC, a Th2 type chemokine, by KCs. This may partially contribute to maintaining Th1/Th2 balance in inflammatory skin diseases like atopic dermatitis.

The action of a novel vitamin D3 analogue, OCT, on immunomodulatory function of keratinocytes and lymphocytes

Abstract Topical vitamin D 3 has relatively recently been introduced for the treatment of psoriasis. Synthetic vitamin D 3 analogues with a high potential for inducing differentiation of cells, but with a low hypercalcemic effect have recently been developed. One such synthetic analogue of 1,25-dihydroxyvitamin D 3 (calcitriol), 22-oxacalcitriol (OCT), is a novel agent for the topical treatment of psoriasis. The activity of OCT in vitro was investigated and compared with that of a series of vitamin D 3 analogues as to their ability to inhibit murine T lymphocyte proliferation stimulated by con-A, to suppress IL-6 and IL-8 production by keratinocytes stimulated with IL-1α and TNFα, and to inhibit AP-1- and NFκB-dependent reporter gene expression. OCT inhibited the proliferation of lymphocytes and suppressed IL-8 and IL-6 production by keratinocytes to the same extent as the other vitamin D 3 analogues. It also inhibited AP-1- and NFκB-controlled luciferase activity to the same extent as the other vitamin D 3 analogues, which demonstrates its mechanism of action in the suppression of inflammatory processes.

An Open Trial of Oral Macrolide Treatment for Psoriasis Vulgaris

Seventeen patients were included in a clinical open trial of macrolides for treatment of psoriasis vulgaris. PASI scores, itch and ointment scores were used to evaluate their effectiveness. PASI scores dropped from 22.8 to 13.7; this was statistically significant. Itch reduced in 11 out of 13 patients, and the extent of itch reduced significantly by 54% on average. Ointment scores reduced from 44.9 to 34.4, which was also statistically significant. Macrolides are known not only as potent anti‐biotics, but also as immunomodulatory agents. These data suggest that macrolides could be used as one of the adjunctive therapies of psoriasis vulgaris, and this study is a first step toward the future evaluation of macrolides in a double blind trial.