330 The aryl hydrocarbon receptor contributes to histamine-evoked itch with the involvement of TRPV1 in dorsal root ganglia

Aryl hydrocarbon receptor (AhR) is a transcription factor that plays crucial role in skin homeostasis, regeneration and barrier. Tapinarof, an agonist of AhR, was reported to improve pruritus patients with atopic dermatitis; however, the AhR regulating itch remains unknown. Therefore, we aimed investigate regulation. Pruritogens, including histamine, chloroquine, trypsin serotonin were intradermally injected into AhR-knockout mice their wild-type (WT) littermates itch-related scratching behavior assessed. Mice dorsal root ganglia (DRG) obtained for further analysis. Moreover, normal human epidermal keratinocytes transfected siRNA mRNA expression evaluated by real-time PCR. We observed exhibited increased histamine-evoked bouts compared WT mice. Notably, no significant differences between number scratch elicited serotonin. Furthermore, confirmed expressed DRG. In addition, transient potential vanilloid 1 (TRPV1) DRG mice, whereas TRPV1 showed changes nerve elongation factors such as growth amphiregulin upregulated artemin siRNA. Together, these observations indicate involved histamine-induced modulates axon guidance molecules.