Possible Antipruritic Mechanism of Cyclosporine A in Atopic Dermatitis.

Cyclosporine A is an immunosuppressive agent that suppresses pruritus and is currently used in the treatment of patients with severe atopic dermatitis. The aim of this study was to elucidate the antipruritic mechanism of cyclosporine A using a mouse model of atopic dermatitis. Intraperitoneal injection of cyclosporine A (5 mg/kg) significantly reduced epidermal nerve density, number of scratching bouts, dermatitis scores, and transepidermal water loss, as well as decreasing the numbers of inflammatory cells in the dermis and decreasing epidermal thickness. Intraperitoneal injection of cyclosporine A dose-dependently inhibited increased itch-related receptor gene expression, such as interleukin-31 receptor A and neurokinin-1 receptor, in the dorsal root ganglion of atopic dermatitis model mice. Thus, the antipruritic efficacy of cyclosporine A may involve reduced epidermal nerve density and expression levels of itch-related receptor genes in the dorsal root ganglion, as well as improvement in acanthosis and reduction in cutaneous inflammatory cell number.

Differences in therapeutic effects of topically applied corticosteroid and tacrolimus on atopic dermatitis-like symptoms in NC/Nga mice.

BACKGROUND: Topical corticosteroid and calcineurin inhibitor have similar therapeutic benefits in atopic dermatitis (AD), but the differences in therapeutic mechanisms of action of these agents against AD symptoms are not fully understood. OBJECTIVE: This study was performed to examine the different effects of topical betamethasone valerate (BMV), clobetasol propionate (CBP), and tacrolimus (TAC) on itch-related behavior and dermatitis in NC/Nga mice with AD-like symptoms. METHODS: AD-like dermatitis was induced in the dorsal skin of NC/Nga mice by repeated topical application of Dermatophagoides farinae body (Dfb) ointment twice weekly for three weeks. Mice with dermatitis scores over 5 were divided into five groups with equal dermatitis scores and treated with BMV, CBP, TAC, or Vaseline (Vas) once daily for two consecutive days, or were not treated (NT). Scratching behavior was analyzed using a SCLABA®-Real system. Transepidermal water loss (TEWL) before and after treatment was measured using a Tewameter® TM210. Skin collected from each group was analyzed histologically. RESULTS: After the second treatment, dermatitis showed significantly greater improvement in the CBP and TAC-treated groups than in the Vas-treated and NT groups. The numbers of scratching bouts were significantly lower in CBP and TAC-treated mice than in Vas-treated mice. TEWL was significantly lower in TAC-, but not in CBP-, treated mice than in Vas-treated mice. Immunohistochemical examination showed that BMV, CBP and TAC did not reduce the increased densities of epidermal protein gene product 9.5- and substance P-immunoreactive fibers. The numbers of dermal CD4-immunoreactive T cells were significantly lower in BMV and CBP-treated mice than in Vas-treated and NT mice. The numbers of dermal eosinophils were significantly lower in BMV, CBP and TAC-treated mice than in Vas-treated and NT mice, with CBP showing the strongest effect. CBP significantly reduced epidermal thickness compared with Vas and NT. There were no significant differences in the numbers of interleukin-31-immunoreactive cells and mast cells, or in expression of epidermal thymic stromal lymphopoietin among all five groups. CONCLUSION: The therapeutic potency of TAC against AD-like symptoms, including pruritus, is equal to that of the corticosteroid CBP. Epidermal innervation of sensory nerves itself might not be related to the therapeutic effects of topical tacrolimus and corticosteroids in its early phase.

A gene variant in the Atp10d gene associates with atherosclerotic indices in Japanese elderly population.

BACKGROUND: ATP10D belongs to a subfamily of P-type ATPases implicated in phospholipids translocation from the exoplasmic to the cytoplasmic leaflet of cellular biological membrane. Previous genome-wide association study (GWAS) identified that a variant in Atp10d gene (rs2351791) associates with serum lipid profile and myocardial infarction. The objective of this study is to assess the effect of this variant on atherosclerosis in Japanese elderly population. METHOD: Consecutive autopsy cases registered in JG-SNP study were recruited (n = 1536). The samples were pathologically assessed for atherosclerosis using macroscopic examination of the formalin-fixed arteries, and coronary stenotic index (CSI), intracranial atherosclerotic index (ICAI) and pathological atherosclerotic index (PAI), which represent systemic arteries were calculated. The variant rs2351791 (G/T) in Atp10d gene was genotyped by Taqman genotyping assay and association determined. RESULT: Both CSI and ICAI were significantly higher in GG genotype than GT genotype and TT genotype (p = 0.003 and p = 0.001, respectively). Both associations remained significant in minor allele dominant model after adjusting for age, hypertension, diabetes, HDL, smoking and drinking (p = 0.001 and p = 0.001, respectively). PAI was not associated with this variant. Consistent with the previous report, plasma HDL cholesterol level was lower in GG genotype compared to GT + TT genotypes (p = 0.001). CONCLUSION: The rs2351791 SNP in the Atp10d gene affects the susceptibility for cardiac and intracranial vascular stenosis in the elderly Japanese population.