Upregulated E3 ligase tripartite motif-containing protein 21 in psoriatic epidermis ubiquitylates nuclear factor-kappa B p65 subunit and promotes inflammation in keratinocytes
Upregulated E3 ligase tripartite motif-containing protein 21 in psoriatic epidermis ubiquitylates nuclear factor-kappa B p65 subunit and promotes inflammation in keratinocytes
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银屑病表皮中上调的 E3 连接酶三联基序蛋白 21 泛素化核因子 kappa B p65 亚基并促进角质形成细胞炎症
DOI：
10.1111/bjd.19057
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发表时间：
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影响因子：
10.3
通讯作者：
Wang G.
中科院分区：
文献类型：
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作者：
Yang L.;Zhang T.;Zhang C.;Xiao C.;Bai X.;Wang G.
研究背景含有三分基序的蛋白21（Trim 21）是一种E3泛素蛋白连接酶，在多种疾病中起关键作用。然而，它在介导角质形成细胞炎症中的作用，这是银屑病的一个标志，尚未彻底阐明。ObjectivesTo澄清是否Trim 21在调节银屑病角质形成细胞炎症中起着关键作用，材料和方法通过定量真实的时间聚合酶链反应检测细胞因子和趋化因子的分泌Trim 21敲低的人角质形成细胞中的qPCR反应。使用免疫印迹、免疫沉淀和免疫荧光评价Trim 21的下游途径和底物。采用体外泛素化试验、免疫沉淀和免疫荧光法检测Trim 21泛素化对其底物的影响。靶向Trim 21治疗银屑病的有效性进行了assessedin vivowith苏木精和伊红染色，免疫荧光和qPCR.ResultsKnocking下来Trim 21表达减轻角质形成细胞炎症。Trim 21与p65/核因子（NF）-κB共定位于胞质溶胶中，并通过赖氨酸63（K63）连接物理结合和泛素化p65。Trim 21并没有改变p65蛋白的稳定性，而是增强了p65与IκB激酶的相互作用，从而促进了p65的磷酸化、核转运和下游基因的激活。最后，体外和体内实验均证实，局部应用Trim 21特异性小干扰RNA显著改善了咪喹莫特诱导的银屑病样lesions.ConclusionsOur研究证实，银屑病表皮中上调的Trim 21使p65泛素化并激活NF-κB通路，从而促进角质形成细胞炎症。因此，Trim 21代表了银屑病治疗的潜在靶点。
BackgroundTripartite motif‐containing protein 21 (Trim21) is an E3 ubiquitin‐protein ligase that plays pivotal roles in various diseases. However, its role in mediating keratinocyte inflammation, which is a hallmark of psoriasis, has not been thoroughly elucidated.ObjectivesTo clarify whether Trim21 plays a pivotal role in regulating keratinocyte inflammation in psoriasis, while focusing on identifying key Trim21 substrates involved in mediating proinflammatory cytokine and chemokine production.Materials and methodsCytokine and chemokine secretion was examined by quantitative real‐time polymerase chain reaction (qPCR) in Trim21‐knockdown human keratinocytes. Downstream pathways and substrates of Trim21 were evaluated using immunoblotting, immunoprecipitation and immunofluorescence. The influence of Trim21 ubiquitination on its substrates was tested byin vitroubiquitination assay, immunoprecipitation and immunofluorescence. The effectiveness of targeting Trim21 for psoriasis treatment was assessedin vivowith haematoxylin and eosin staining, immunofluorescence and qPCR.ResultsKnocking down Trim21 expression alleviated keratinocyte inflammation. Trim21 colocalized with p65/nuclear factor (NF)‐κB in the cytosol and physically bound and ubiquitinated p65 via a lysine 63 (K63) linkage. Instead of changing p65 protein stability, Trim21 enhanced the interaction of p65 with IκB kinase, which promoted p65 phosphorylation, nuclear transport and downstream gene activation. Finally, bothin vitroandin vivoexperiments verified that topical application of Trim21‐specific small interfering RNA markedly ameliorated imiquimod‐induced psoriasis‐like lesions.ConclusionsOur study confirms that upregulated Trim21 in psoriatic epidermis ubiquitylates p65 and activates the NF‐κB pathway, which promotes keratinocyte inflammation. Hence, Trim21 represents a potential target for psoriasis treatment.