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Yuichiro Tsunemi

Publications and source records attributed to Yuichiro Tsunemi.

At least 19 recordsLinked to original sources
PubMed2006

Macrophage-derived chemokine (MDC)/CCL22 produced by monocyte derived dendritic cells reflects the disease activity in patients with atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is a recurrent inflammatory skin disease characterized by high serum levels of IgE and Th2-type cytokines such as IL-4, IL-5 or IL-13. Chemokines attract leukocytes in inflamed tissues. We have previously found that thymus and activation regulated chemokine (TARC)/CCL17 and macrophage-derived chemokine (MDC)/CCL22 are highly secreted in the plasma levels of AD patients. Dendritic cells (DCs) are antigen-presenting cells that are divided into two subgroups including monocyte derived DCs (MoDCs) and plasmacytoid DCs (pDCs). OBJECTIVES: The aim of the study was to elucidate CCL17 and CCL22 production by MoDCs in AD patients, psoriasis vulgaris (PsV) patients and healthy controls (HC). METHODS: MoDCs were obtained from AD patients, PsV patients or HC and were cultured. In addition, the chemokine levels were measured in the supernatants. RESULTS: We found that the CCL22 levels produced by MoDCs in AD patients to be significantly higher than those of PsV patients and HC. There was a significant correlation between the CCL22 levels produced by MoDCs and the SCORAD index. No significant difference in the CCL17 levels produced by MoDCs was detected among AD patients, PsV patients or HC. Immunosuppressive drugs such as dexamethasone (Dex), tacrolimus and cyclosporine (Cys) inhibited the CCL22 production by MoDCs in the AD patients. CONCLUSION: These data suggest that the CCL22 level produced by MoDCs thus reflects the disease activity of AD and it may also play an important role regarding the production of CCL22 in the pathogenesis of AD.

Adolescent↗
PubMed2006

CCL17 transgenic mice show an enhanced Th2-type response to both allergic and non-allergic stimuli.

CC chemokine ligand (CCL)17 is implicated in the pathogenesis of atopic dermatitis (AD). To study the effect of CCL17 produced by keratinocytes (KC) during inflammation, we created transgenic (Tg) mice in which CCL17 is overexpressed in KC. Th2-type contact hypersensitivity (CHS) was enhanced and Th1-type CHS was suppressed in these mice. Increased numbers of CC chemokine receptor (CCR)4(+) cells and mast cells infiltrated in Tg mice. Levels of IL-4 mRNA were higher and those of IFN-gamma mRNA were lower in both acute and chronic CHS. Higher levels of serum IgE were observed after CHS. Numbers of CCR4(+) cells among PBMC were increased in Tg mice challenged acutely on the trunk. Chronic irritation with croton oil induced dermatitis and an elevation of serum IgE levels. Tg mice showed enhanced ear swelling after tape stripping. CCL17 was thought to modify the inflammation caused by sensitizing reagents as well as irritant reagents by attracting CCR4(+) cells into the lesional skin and creating a Th2-dominant condition. AD-like conditions such as increased number of mast cells and elevated levels of serum IgE were observed. Thus, CCL17 may participate in the pathogenesis of skin diseases such as AD by regulating both allergic and irritant inflammation.

Acute Disease↗
PubMed2006

Novel mutation (Asp158Val) in H1 domain of keratin 5 gene in a Japanese patient with Köbner-type epidermolysis bullosa simplex.

We describe a 19-year-old Japanese male with Köbner-type epidermolysis bullosa simplex (EBS-KB) with a novel keratin gene mutation. The patient developed blisters on the feet, palms, elbows and knees soon after birth. His father is similarly affected with blistering, but his mother and younger brother are not affected. Histological examination revealed that the primary separation in the blister occurred within the basal cell layer. Sequence analysis demonstrated an A-to-T transition at the second position of codon 158 in the keratin 5 (K5) gene. The amino acid at codon 158 was deduced to have changed from asparagine to valine. We identified a novel mutation (Asp158Val) in the H1 domain of the K5 gene in this Japanese patient with EBS-KB. This is the first gene mutation report of EBS-KB in the H1 domain of the K5 gene.

Adult↗
PubMed2006

CCL28 production in HaCaT cells was mediated by different signal pathways from CCL27.

Both CCL27 and CCL28 are ligands for CCR10 and attract CCR10(+) lymphocytes. We previously demonstrated that CCL27 and CCL28 were strongly expressed in sera and lesional keratinocytes of patients with atopic dermatitis and psoriasis vulgaris. However, the regulation of CCL27 and CCL28 production in keratinocytes has not been well documented. In this study, we showed that CCL27 and CCL28 expression and production by a human keratinocyte cell line, HaCaT cells, were strongly induced by inflammatory cytokines tumor necrosis factor-alpha and interleukin-1beta. CCL27 production was downregulated by inhibitors of p38 mitogen-activated protein kinase and nuclear factor-kappa B (NF-kappaB). By contrast, CCL28 production was downregulated by inhibitors of extracellular signal-regulated kinase and NF-kappaB. Our study results suggest that CCL28 produced by keratinocytes is mediated by different signal pathways from CCL27 and that both CCL27 and CCL28 are involved in the pathogenesis of inflammatory skin diseases.

Cell Line↗
PubMed2005

Gene mutation analysis in five cases of dermatofibrosarcoma protuberans using formalin-fixed, paraffin-embedded tissues.

Fusion of the collagen type I a 1 (COL1A1) gene with the platelet-derived growth factor B-chain (PDGFB) gene has been pointed out in dermatofibrosarcoma protuberans. Various exons of the COL1A1 gene have been shown to be involved in the fusion with exon 2 of the PDGFB gene. We studied the breakpoints of the COL1A1 gene using formalin-fixed, paraffin-embedded tumour specimens from five patients with dermatofibrosarcoma protuberans (three reconfirmations and two new cases). Reverse transcriptase-PCR was performed using paraffin-embedded tissues. Nucleotide sequence analysis was carried out using the PCR products to identify the breakpoints. The COL1A1-PDGFB fusion transcripts were detected from the tumour specimens. Sequence analysis revealed that the ends of exons 18, 29, 38, 42 and 44 in the COL1A1 gene were fused with the start of exon 2 in the PDGFB. This study identified a novel COL1A1 breakpoint, namely, exon 44 of the COL1A1 gene. Detection of the aberrant fusion transcript using formalin-fixed, paraffin-embedded tumour specimens is useful as a diagnostic aid for dermatofibrosarcoma protuberans in cases where fresh or frozen samples of tumour tissue are not available.

Adolescent↗
PubMed2004

Enhanced TARC production by dust-mite allergens and its modulation by immunosuppressive drugs in PBMCs from patients with atopic dermatitis.

BACKGROUND: Thymus and activation regulated chemokine (TARC) is a CC chemokine that attracts CCR4+ T cells. We reported previously that TARC is an important chemokine that defines Th2 imbalance in the pathogenesis of atopic dermatitis (AD). OBJECTIVES: This study was undertaken to clarify TARC producing cells in peripheral blood mononuclear cells (PBMCs), the regulation of dust mite-allergen clude extract (DME) and different immunosuppressive drugs (Tacrolimus (FK506), cyclosporine (CsA), dexamethasone (Dex)) on TARC production by peripheral PBMCs from AD patients in vitro. METHODS: Monocyte derived dendritic cells (MoDCs) were generated from and TARC mRNA levels were examined and comapared with those from T cells in PBMCs from AD patients. PBMCs were cultured with or without DME and/or immunosuppressive drugs (Tacrolimus, CsA, Dex) for 7 days and TARC levels were measured. RESULTS: PBMCs from AD patients which were cultured with DME stimulation for 7 days showed significantly higher levels of TARC production than those from healthy controls. RT-PCR demonstrated that TARC mRNA was expressed in CD4+ T cells, CD8+ T cells and MoDCs. Tacrolimus, CsA and Dex individually suppressed TARC production by PBMCs from AD patients which were co-cultured with DME for 7 days. Gel shift analysis revealed differential inhibitory effects of these immunosuppressive drugs on NFkappaB activity in PBMCs from AD patients. CONCLUSION: Our data demonstrate that TARC producing cells are MoDCs, T cells as well as epidermal keratinocytes in AD. We suggest that MoDCs might regulate the immune responses by attracting T cells and CD25+ T cells in the pathogenesis of AD. We also showed the important role of DME on TARC production and the inhibitory effect of the immunosuppressive drugs on TARC production by PBMCs from AD patients, that can regulate ongoing immune responses in the pathogenesis of AD.

Adult↗
PubMed2004

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.

Adolescent↗
PubMed2004

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. OBJECTIVES: To examine whether the -431C>T SNP of the TARC gene is associated with susceptibility to AD and whether it affects the promoter activity of the TARC gene. METHODS: We investigated the genotype and allele frequencies of the SNP in 193 AD patients and 158 healthy controls by polymerase chain reaction-restriction fragment length polymorphism method. We compared the promoter activities between TARC promoter carrying 431C and that carrying -431T by transient-transfection assay in DJM-1 cell line. RESULTS: There were no significant differences in genotype or allele frequencies between AD patients and controls (genotype: P = 0.38, allele: P = 0.22). Luciferase activity was higher in -431T constructs than in -431C constructs (2.3-fold, P = 9.5 x 10(-6)). CONCLUSION: These results suggest that the -431C>T SNP of the TARC gene enhances the promoter activity of TARC gene but is not associated with susceptibility to AD in Japanese population.

Adolescent↗
PubMed2004

The lesional skin of linear IgA bullous dermatosis expresses growth-regulated peptide (GRO)-alpha.

The patient was a 62-year-old man with erythema with tense vesiculobullae and erosions on the bilateral elbows, right knee, and one buttock. A skin biopsy specimen revealed subepidermal blister formation with a predominant infiltration of neutrophils and papillary neutrophilic microabscesses. Direct immunofluorescence study showed linear deposition of IgA and weak deposition of IgG at the basement membrane zone of the lesional skin, and indirect immunofluorescence study showed linear deposition of IgA at the epidermal side of the 1M NaCl-separated normal skin. He was diagnosed with linear IgA bullous dermatosis. Immunohistochemical study revealed that the lesional and perilesional keratinocytes expressed growth-regulated peptide (GRO) -alpha, a potent chemoattractant for neutrophils. This suggests that GRO-alpha plays a role in the infiltration of neutrophils into the lesional skin and in bulla formation in linear IgA bullous dermatosis.

Autoantibodies↗