Characterization of multiple P2X receptors in cultured normal human epidermal keratinocytes

Kaori Inoue, Mitsuhiro Denda, Hidetoshi Tozaki, Kayoko Fujishita, Schuichi Koizumi, Kazuhide Inoue

研究成果: Contribution to journalArticle査読

46 被引用数 (Scopus)


ATP-gated ion channels (P2X) are expressed in human epidermis and cultured keratinocytes. The aim of this study was to characterize native P2X receptors in normal human epidermal keratinocytes (NHEK) using whole-cell patch clamp technique, RT-PCR, and determination of intracellular Ca2+ concentration ([Ca2+]i). Application of ATP resulted in an inward current with a reversal potential of 0 mV. Response to ATP showed two types of currents: the slowly desensitizing response and the rapidly desensitizing response. The slowly desensitizing response was blocked by iso-pyridocaphosphate-6-azophenyl-2′,5′ disulfonic acid (PPADS), a P2X receptor antagonist. We found that the expression of multiple P2X 2, P2X3, P2X5, and P2X7 receptor subtype mRNA was increased in differentiated cells. On the other hand, the expression of G-protein-coupled P2Y2 mRNA was downregulated in differentiated cells. Increases in [Ca2+]i evoked by αβ-methylene ATP (αβ-meATP) and 2′,3′-O-(4- benzoylbenzoyl) ATP (BzATP) were elevated, whereas elevation of [Ca 2+]i evoked by uridine 5′-triphosphate (UTP) was decreased in differentiated cells. Application of ATP or UVB radiation increased the expression of P2X1, P2X2, P2X3, and P2X7 receptors in NHEK. Changes in the expression levels and cation influx via multiple P2X receptors might be involved in the regulation of differentiation and one of the epidermal external sensors.

ジャーナルJournal of Investigative Dermatology
出版ステータス出版済み - 4 2005

All Science Journal Classification (ASJC) codes

  • 生化学
  • 分子生物学
  • 皮膚病学
  • 細胞生物学


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