A tryptophan metabolite of the skin microbiota attenuates inflammation in patients with atopic dermatitis through the aryl hydrocarbon receptor - 06/06/19
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Abstract |
Background |
Previous studies have revealed significant alterations in the skin microbiota of patients with atopic dermatitis (AD) not only in diversity and composition but also in function, and the tryptophan (Trp) metabolic pathway is attenuated in the skin microbiota of patients with AD.
Objective |
We sought to assess Trp metabolites on the skin surfaces of patients with AD and to explore the function of the microbial Trp metabolites in skin inflammation in patients with AD.
Methods |
A gel-patch method was developed to collect metabolites on the skin surface, which were then assessed by using liquid chromatography–tandem mass spectrometry. A mouse model of calcipotriol (MC903)–induced AD-like dermatitis was used to evaluate the effects of microbial metabolites on AD, and aryl hydrocarbon receptor (AhR)–null mice and keratinocyte cultures were used to investigate the mechanism.
Results |
Major microbial metabolites of Trp were detected on the skin surfaces of healthy subjects, and the level of indole-3-aldehyde (IAId), an indole derivative of Trp catabolism, was significantly lower in lesional and nonlesional skin of patients with AD than that of healthy subjects. IAId significantly attenuated skin inflammation in mice with MC903-induced AD-like dermatitis, and this effect was blocked by an AhR antagonist and abolished in AhR-null mice. Furthermore, IAId was found to inhibit the MC903-induced expression of thymic stromal lymphopoietin in keratinocytes in vivo and in vitro, which was mediated by binding of AhR to the thymic stromal lymphopoietin promoter.
Conclusion |
IAId, a skin microbiota–derived Trp metabolite, negatively regulated skin inflammation in patients with AD, revealing that skin microbiota play a significant functional role in the pathogenesis of AD.
Le texte complet de cet article est disponible en PDF.Graphical abstract |
Key words : Atopic dermatitis, skin, microbiota, tryptophan, metabolites, indole-3-aldehyde, aryl hydrocarbon receptor, thymic stromal lymphopoietin
Abbreviations used : AD, AhR, AhRE, CHS, CYP1A1, DMSO, FACS, 5-HTP, IAA, IAId, IMQ, KYN, LC-MS/MS, OXA, SCFA, siRNA, Trp, TSLP
Plan
Supported by the National Natural Science Foundation of China (81573038, 91642116, 81573045, and 31400782), the CAMS Innovation Fund for Medical Sciences (2016-I2M-1-005), the Natural Science Foundation of Jiangsu Province (BK20151066 and BK20170162), and the Milstein Medical Asian American Partnership Foundation. W.L. was founded by a Municipal Human Resources Development Program for Outstanding Leaders in Medical Disciplines in Shanghai (2017BR039). |
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Disclosure of potential conflict of interest: The authors declare that they have no relevant conflicts of interest. |
Vol 143 - N° 6
P. 2108 - juin 2019 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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