title: Yokukansan, a traditional Japanese medicine, adjusts glutamate signaling in cultured keratinocytes.
abstract: Glutamate plays an important role in skin barrier signaling. In our previous study, Yokukansan (YKS) affected glutamate receptors in NC/Nga mice and was ameliorated in atopic dermatitis lesions. The aim of this study was to assess the effect of YKS on skin and cultured human keratinocytes. Glutamate concentrations in skin of YKS-treated and nontreated NC/Nga mice were measured. Then, glutamate release from cultured keratinocytes was measured, and extracellular glutamate concentrations in YKS-stimulated cultured human keratinocytes were determined. The mRNA expression levels of NMDA receptor 2D (NMDAR2D) and glutamate aspartate transporter (GLAST) were also determined in YKS-stimulated cultured keratinocytes. The glutamate concentrations and dermatitis scores increased in conventional mice, whereas they decreased in YKS-treated mice. Glutamate concentrations in cell supernatants of cultured keratinocytes increased proportionally to the cell density. However, they decreased dose-dependently with YKS. YKS stimulation increased NMDAR2D in a concentration-dependent manner. Conversely, GLAST decreased in response to YKS. Our findings indicate that YKS affects peripheral glutamate signaling in keratinocytes. Glutamine is essential as a transmitter, and dermatitis lesions might produce and release excess glutamate. This study suggests that, in keratinocytes, YKS controls extracellular glutamate concentrations, suppresses N-methyl-D-aspartate (NMDA) receptors, and activates glutamate transport.
authors.affiliation: Department of Dermatology and Allergology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
authors.forename: Maki
authors.identifier: 0000-0002-8838-2976
authors.initials: M
authors.lastname: Wakabayashi
authors.affiliation: Department of Dermatology and Allergology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Hasegawa
authors.affiliation: Center for Advanced Kampo Medicine and Clinical Research, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan ; Tsumura Research Laboratories, Tsumura & Co, 3586 Yoshiwara, Ami-machi, Inashiki-gun, Ibaraki 300-0075, Japan.
authors.forename: Takuji
authors.initials: T
authors.lastname: Yamaguchi
authors.affiliation: Department of Dermatology and Allergology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Funakushi
authors.affiliation: Department of Dermatology and Allergology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan ; Atopy (Allergy) Research Center, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
authors.forename: Hajime
authors.identifier: 0000-0002-5496-7562
authors.initials: H
authors.lastname: Suto
authors.affiliation: Department of Dermatology and Allergology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
authors.forename: Rie
authors.initials: R
authors.lastname: Ueki
authors.affiliation: Center for Advanced Kampo Medicine and Clinical Research, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kobayashi
authors.affiliation: Department of Dermatology and Allergology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan ; Atopy (Allergy) Research Center, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
authors.forename: Hideoki
authors.initials: H
authors.lastname: Ogawa
authors.affiliation: Department of Dermatology and Allergology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan ; Atopy (Allergy) Research Center, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
authors.forename: Shigaku
authors.initials: S
authors.lastname: Ikeda
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D003872:Dermatitis / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000494:pharmacology*; D027341:Excitatory Amino Acid Transporter 1 / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D018698:Glutamic Acid / Q000378:metabolism*; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008519:Medicine, Traditional; D051379:Mice; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D012867:Skin / Q000378:metabolism / Q000473:pathology; D013997:Time Factors
chemical_list: D004365:Drugs, Chinese Herbal; D027341:Excitatory Amino Acid Transporter 1; D012333:RNA, Messenger; D016194:Receptors, N-Methyl-D-Aspartate; C493394:SLC1A3 protein, human; C524644:Yi-Gan San; D018698:Glutamic Acid