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Updated: Dec 18, 2025

Pharmacologic Induction of Epidermal Melanin and Protection Against Sunburn in a Humanized Mouse Model
Published on: September 7, 2013
Solar light induces the release of acetylcholine from skin keratinocytes affecting melanogenesis
Qiyun Wu1,2, Yiteng Xia2, Kun Dai1,2
1Shenzhen Key Laboratory of Edible and Medicinal Bioresources, Shenzhen Research Institute, Shenzhen, China.
Abstract:
Cholinergic system conducts signal transmission in brain and muscle. Besides nervous system, the nonneuronal functions of cholinergic system have been proposed in various tissues. The expression of cholinergic proteins and release of acetylcholine in human skin have been reported, but its mechanism and influence on dermatological functions is not elucidated. Here, the expression profile of cholinergic markers was further investigated in skin and keratinocyte. The expression levels of choline acetyltransferase (ChAT), acetylcholinesterase (AChE), vesicular acetylcholine transporter (VAChT), and synaptophysin, were upregulated during differentiation of keratinocytes. In cultured keratinocytes, a transient exposure of solar light induced the release of acetylcholine, which was mediated by intracellular Ca2+ mobilization. The light-induced acetylcholine release was mediated by the present of opsin. The light-induced melanogenesis was inhibited by acetylcholine or AChE inhibitor in melanocyte in vitro and mouse skin ex vivo. These results indicated that the potential role of cholinergic system could be a negative regulator in skin pigmentation.
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