Noriko Asano

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.

B Lymphocyte signaling established by the CD19/CD22 loop regulates autoimmunity in the tight-skin mouse.

Systemic sclerosis (SSc) is characterized by fibrosis and autoimmmunity. Peripheral blood B cells from SSc patients specifically overexpress CD19, a critical cell-surface signal transduction molecule in B cells. CD19 deficiency in B cells also attenuates skin fibrosis in the tight-skin (TSK/+) mouse, a genetic model for SSc. Herein we analyzed two transgenic mouse lines that overexpress CD19. Remarkably, 20% increase of CD19 expression in mice spontaneously induced SSc-specific anti-DNA topoisomerase I (topo I) antibody (Ab) production, which was further augmented by 200% overexpression. In TSK/+ mice overexpressing CD19, skin thickness did not increase, although anti-topo I Ab levels were significantly augmented, indicating that abnormal CD19 signaling influences autoimmunity in TSK/+ mice and also that anti-topo I Ab does not have a pathogenic role. The molecular mechanisms for abnormal CD19 signaling were further assessed. B-cell antigen receptor crosslinking induced exaggerated calcium responses and augmented activation of extracellular signal-regulated kinase in TSK/+ B cells. CD22 function was specifically impaired in TSK/+ B cells. Consistently, CD19, a major target of CD22-negative regulation, was hyperphosphorylated in TSK/+ B cells. These findings indicate that reduced inhibitory signal provided by CD22 results in abnormal activation of signaling pathways including CD19 in TSK/+ mice and also suggest that this disrupted B cell signaling contribute to specific autoantibody production.

Interleukin-13 gene polymorphism G4257A is associated with atopic dermatitis in Japanese patients

Interleukin (IL)-13 plays an important role in the induction of immunoglobulin E (IgE) and in the pathogenesis of atopic dermatitis (AD). We investigated the allele and genotype frequencies of three IL-13 single nucleotide polymorphisms (SNPs) (A704C and C1103T in the promoter region and G4257A in exon 4) in Japanese patients with AD. For A704C and C1103T SNPs, there were no significant differences in allele or genotype frequencies between AD patients and controls. For G4257A SNP, A allele was significantly increased in AD patients (39.5%) compared with controls (29.4%) (P = 0.016). The same proportion of each genotype and allele was observed in the patient subgroup with and without asthma. Serum IgE levels and peripheral eosinophil counts were not significantly different among genotypes in G4257A SNP. There was also no significant difference in allele or genotype frequencies between AD patients with mild disease and those with severe disease, between those with family history of AD and those without it, or between those with family history of atopic disorders and those without it. This result suggests that 4257A allele is associated with susceptibility to AD and that it may function in the pathogenesis of AD itself, presumably by other mechanisms than inducing IgE production.

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.

Eotaxin gene single nucleotide polymorphisms in the promoter and exon regions are not associated with susceptibility to atopic dermatitis, but two of them in the promoter region are associated with serum IgE levels in patients with atopic dermatitis

Eotaxin is believed to play an important role in atopic dermatitis (AD) as a potent chemoattractant and activator of eosinophils and Th2 lymphocytes. The eotaxin gene is located at chromosome 17q21.1-q21.2, and linkage findings of AD on chromosome 17 were reported. Recently we have identified single nucleotide polymorphisms (SNPs) of eotaxin gene (-426C > T, -384A > G, 67G > A). To learn whether eotaxin gene SNPs are associated with susceptibility to AD or phenotypes of AD, we investigated the genotype frequencies at each SNP of the gene in AD patients and in controls. We examined 140 Japanese AD patients and 140 healthy Japanese individuals. Genotyping was performed using the polymerase chain reaction-restriction fragment length polymorphism method. No significant difference was observed in allele or genotype frequencies of any SNP between AD patients and controls. Serum immunoglobulin E (IgE) levels were significantly lower in CT and TT genotype than in CC (P = 0.038) in -426C > T SNP, and lower in GG than in AA and AG with borderline significance (P = 0.053) in -384A > G SNP in AD patients. Eotaxin gene SNPs in the promoter and exon regions are not associated with susceptibility to AD, but two of them in the promoter region are associated with phenotype of AD.

The -431C>T polymorphism of thymus and activation-regulated chemokine increases the promoter activity but is not associated with susceptibility to atopic dermatitis in Japanese patients.

Background:  Thymus and activation‐regulated chemokine (TARC) plays an important role in the pathogenesis of atopic dermatitis (AD). We recently detected the single nucleotide polymorphism (SNP) (−431C>T) in the 5′‐flanking region of TARC gene.

Lack of association of CCR4 single nucleotide polymorphism with atopic dermatitis in Japanese patients

CCR4, a member of the CC chemokine receptor family, is believed to play an important role in the pathogenesis of atopic dermatitis. To examine whether CCR4 single nucleotide polymorphism (SNP) is associated with susceptibility to atopic dermatitis, we investigated the allele and genotype frequencies of C1014T SNP of CCR4 in 198 Japanese patients with atopic dermatitis and controls by a PCR-restriction fragment length polymorphism method. There was no significant difference in allele or genotype frequencies between patients with atopic dermatitis and controls. Serum IgE levels and peripheral blood eosinophil counts were not significantly different among genotypes. There was also no significant difference in allele or genotype frequencies between the patient subgroup with and without asthma, with mild or moderate disease, with and without family history of atopic dermatitis, or with and without family history of atopic disorders. C1014T SNP of CCR4 does not appear to be associated with susceptibility to atopic dermatitis in Japanese patients.

Dermatofibrosarcoma protuberans with COL1A1 (exon 18) –PDGFB (exon 2) fusion transcript

Summary  Background Fusion of the collagen type I α 1 (COL1A1) gene with the platelet‐derived growth factor B‐chain (PDGFB) gene has been described in dermatofibrosarcoma protuberans (DFSP). Various exons of the COL1A1 gene have been shown to be involved in the fusion with exon 2 of the PDGFB gene.

Analysis of GM-CSF gene polymorphisms (3606T ⁄ C and 3928C ⁄ T) in Japanese patients with atopic dermatitis

Granulocyte–macrophage colony‐stimulating factor (GM‐CSF) is thought to play an important role in the pathogenesis of atopic dermatitis. To examine whether GM‐CSF single nucleotide polymorphisms (SNPs) are associated with susceptibility to atopic dermatitis, we investigated the genotype and allele frequencies of the SNPs 3606T/C and 3928C/T of the GM‐CSF gene in 181 Japanese patients with atopic dermatitis and 100 controls, using a PCR restriction fragment length polymorphism method. A strong linkage disequilibrium existed between the polymorphisms 3606 and 3928, suggesting two common GM‐CSF haplotypes, 3606*T‐3928*C and 3606*C‐3928*T. However, there was no significant difference in genotype or allele frequencies between patients with atopic dermatitis and controls for either of the two polymorphisms, thus GM‐CSF SNPs do not appear to be associated with susceptibility to atopic dermatitis in Japanese patients. A large‐scale study is necessary to confirm these findings.

Lack of association of CCR3 single nucleotide polymorphism with atopic dermatitis in Japanese population

CCR4, a member of the CC chemokine receptor family, is believed to play an important role in the pathogenesis of atopic dermatitis. To examine whether CCR4 single nucleotide polymorphism (SNP) is associated with susceptibility to atopic dermatitis, we investigated the allele and genotype frequencies of C1014T SNP of CCR4 in 198 Japanese patients with atopic dermatitis and controls by a PCR-restriction fragment length polymorphism method. There was no significant difference in allele or genotype frequencies between patients with atopic dermatitis and controls. Serum IgE levels and peripheral blood eosinophil counts were not significantly different among genotypes. There was also no significant difference in allele or genotype frequencies between the patient subgroup with and without asthma, with mild or moderate disease, with and without family history of atopic dermatitis, or with and without family history of atopic disorders. C1014T SNP of CCR4 does not appear to be associated with susceptibility to atopic dermatitis in Japanese patients. Key words: atopic dermatitis; CCR4; single nucleotide polymorphism.