A skin-like cytochrome P450 cocktail activates prohaptens to contact allergenic metabolites
A skin-like cytochrome P450 cocktail activates prohaptens to contact allergenic metabolites
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DOI：
10.1038/sj.jid.5700638
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发表时间：
2007-05-01
影响因子：
6.5
通讯作者：
Baron, Jens M.
中科院分区：
文献类型：
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作者：
Bergstrom, Moa Andresen;Ott, Hagen;Baron, Jens M.
变应性接触性皮炎是一种复杂的综合征，代表皮肤暴露于蛋白反应性化学物质的免疫反应。虽然许多接触致敏剂可以直接引起这种疾病，其他（前半抗原）需要激活。关于激活机制的知识仍然有限，但一种可能性是皮肤中细胞色素P450（CYP）酶的代谢激活。我们已经，定量逆转录酶-PCR研究后，在18人皮肤样本中的β-内酰胺酶含量，开发了一个丰富的皮肤样重组人（rh）β-内酰胺酶鸡尾酒使用CYP 1A 1，1B 1，2B 6，2 E1，和3A 5。为了验证rhizoma混合物，使用皮肤样rhizoma混合物、肝样rhizoma混合物、单一rhizoma酶、肝微粒体、角质形成细胞和树突状细胞（DC）测定研究了前半抗原共轭二烯（（5 R）-5-异丙烯基-2-甲基-1-亚甲基-2-环己烯）。在所有基于非细胞的孵育中，包括皮肤样rhizoma鸡尾酒，二烯被激活为敏化环氧化物。发现环外环氧化物代谢物（（7 R）-7-异丙烯基-4-甲基-1-氧杂螺[2.5]辛-4-烯）主要负责二烯的过敏活性。该环氧化物还诱导显著的DC活化，这通过IL-8的上调来指示。皮肤样rhCYP混合物为在CYP介导的前半抗原皮肤代谢的机制研究中使用皮肤组织制备物提供了一种简化的替代方案，并为设计用于评估前半抗原过敏活性的体外预测试验提供了未来的可能性。
Allergic contact dermatitis is a complex syndrome representing immunological responses to cutaneous exposure to protein-reactive chemicals. Although many contact sensitizers directly can elicit this disorder, others ( prohaptens) require activation. Knowledge regarding the activating mechanisms remains limited, but one possibility is metabolic activation by cytochrome P450 (CYP) enzymes in the skin. We have, after quantitative reverse transcriptase-PCR studies of the CYP content in 18 human skin samples, developed an enriched skin-like recombinant human ( rh) CYP cocktail using CYP1A1, 1B1, 2B6, 2E1, and 3A5. To validate the rhCYP cocktail, a prohaptenic conjugated diene ((5R)-5-isopropenyl-2-methyl-1-methylene-2-cyclohexene) was investigated using: the skin-like rhCYP cocktail, a liver-like rhCYP cocktail, single rhCYP enzymes, liver microsomes, keratinocytes, and a dendritic cell ( DC) assay. The diene was activated to sensitizing epoxides in all non-cell-based incubations including the skin-like rhCYP cocktail. An exocyclic epoxide metabolite (( 7R)-7-isopropenyl- 4-methyl-1-oxaspiro[2.5] oct-4-ene) was found to be mainly responsible for the allergenic activity of the diene. This epoxide also induced pronounced DC activation indicated by upregulation of IL-8. The skin-like rhCYP cocktail provides a simplified alternative to using skin tissue preparations in mechanistic studies of CYP-mediated skin metabolism of prohaptens and offers the future possibility of designing in vitro predictive assays for assessment of allergenic activity of prohaptens.