Hidetoshi Tsuda

Dr. Hidetoshi Tsuda

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Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 February 2017 in Journal of Dermatological Science
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Journal Article
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TOTomoyuki Oshio
Tomoyuki Oshio
MKMayumi Komine
Mayumi Komine
HTHidetoshi Tsuda
Hidetoshi Tsuda
STShin-Ichi Tominaga
Shin-Ichi Tominaga
HSHirohisa Saito
Hirohisa Saito
MOMamitaro Ohtsuki
Mamitaro Ohtsuki

Verified
Journal Article
Open access
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MKMIHO KIMURA
MIHO KIMURA
MTMariko Takada
Mariko Takada
MHMd. Razib Hossain Hossain
Md. Razib Hossain Hossain
HTHidetoshi Tsuda
Hidetoshi Tsuda
XXXiaonan Xie
Xiaonan Xie
Genji ImokawaGenji Imokawa
Genji Imokawa
We previously reported that a pathogenic abnormality in the barrier and water-holding functions of the stratum corneum (SC) in the skin of patients with atopic dermatitis (AD) is mainly attributable to significantly decreased levels of total ceramides in the SC. That decrease is mediated by the abnormal expression of a novel ceramide-reducing enzyme, sphingomyelin/glucosylceramide deacylase (SGDase), which is the β-subunit (ASAH1b) of acid ceramidase. In this study, we determined whether mice overexpressing ASAH1b in their epidermis develop AD-like skin symptoms. We generated transgenic (TG) mice overexpressing ASAH1b, regulated by the involucrin promoter, to localize its expression in the upper epidermis. After hair removal using a depilatory cream containing glycolic acid, the TG mice without any visible skin inflammation at 8 weeks of age had increased levels of ASAH1b and decreased levels of SC ceramide, with disrupted barrier functions measured by trans-epidermal water loss compared to the wild-type (WT) mice. Interestingly, enzymatic assays revealed that SGDase activity was not detectable in the skin of the TG mice compared to WT mice. Immunological staining revealed that there was an increased expression level of IL-33 in the epidermis and an accumulation of macrophages in the dermis of TG mice compared to WT mice, which are phenotypic characteristics of AD, that were exacerbated by tape-stripping of the skin. In the skin of the TG mice, the mRNA levels of IL-5, CCL11, IL-22, CXCL10, and IFNγ were significantly upregulated compared to the WT mice, and tape-stripping significantly increased the mRNA levels of IL-4, IL-33, CXCL1, CXCL12, TLR9, and CD163 compared to WT mice. These findings strongly indicate that the skin of the depilatory cream-treated TG mice exists in an atopic dry skin condition that is highly sensitive to various environmental stimuli. The sum of our results suggests that ASAH1b itself, even in the absence of its enzymatic activity, is a major etiologic factor for atopic dry skin symptoms via an unknown mechanism.

18 November 2024 in Experimental Dermatology
Verified
Journal Article
Closed access
MJMeijuan Jin
Meijuan Jin
MKMayumi Komine
Mayumi Komine
HTHidetoshi Tsuda
Hidetoshi Tsuda
MSMiho Sashikawa‐Kimura
Miho Sashikawa‐Kimura
SNSusumu Nakae
Susumu Nakae
MOMamitaro Ohtsuki
Mamitaro Ohtsuki