Zhang Jie, Zhu Jiuling, Chen Xiaowen, Xia Haibin, Yang Luting
Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, China.
Laboratory of Gene Therapy, Department of Biochemistry, College of Life Sciences, Shaanxi Normal University, Xi'an, China.
J Dermatol Sci. 2022 Sep;107(3):160-168. doi: 10.1016/j.jdermsci.2022.09.002. Epub 2022 Sep 6.
Tripartite motif-containing protein 33, a member of the TRIM E3 ligase family, is shown to be involved in tumorigenesis, cell proliferation and inflammation. Alteration of several TRIM family proteins in psoriatic epidermis has been shown to participate in psoriasis pathogenesis. However, little is known about Trim33 expression and its role in psoriasis.
To examine the expression and biological roles of Trim33 in psoriatic process, with a focus on identifying its novel substrates in psoriatic keratinocytes.
Gene expression of Trim33 in biopsies from psoriasis patients compared with healthy volunteers was analysed by quantitative real-time polymerase chain reaction (qPCR) and immunofluorescence (IF). Identification of Trim33 substrates were performed using immunoprecipitation combined with mass spectrometry. Protein expression and localization were assessed by immunoblotting and immunofluorescence. Expression of cytokines was analysed with qPCR.
qPCR and IF analysis revealed increased expression of Trim33 in psoriatic epidermis. Overexpression of Trim33 promoted the expression of psoriasis-related proinflammatory cytokines IL-6, IL-1β and NLRP3 inflammasome. Intriguingly, Trim33 induced lysine 63 (K63)-linked ubiquitination of Annexin A2 (Anxa2), which promoted its interaction with p50/p65 subunits of NF-κB, favoured the retention of p50/p65 in the nucleus and promoted the expression of inflammation-related NF-κB downstream genes.
Our study highlights the upregulation of Trim33 in psoriatic epidermis and its pivotal role in promoting the inflammation of keratinocytes by Anxa2/NF-κB pathway. Our findings imply that Trim33 might be further explored as potential target for psoriasis treatment.
含三联基序蛋白33是TRIM E3连接酶家族成员，已被证明参与肿瘤发生、细胞增殖和炎症反应。银屑病表皮中几种TRIM家族蛋白的改变已被证明参与银屑病的发病机制。然而，关于Trim33在银屑病中的表达及其作用知之甚少。
研究Trim33在银屑病发病过程中的表达及生物学作用，重点是鉴定其在银屑病角质形成细胞中的新底物。
采用定量实时聚合酶链反应（qPCR）和免疫荧光（IF）分析银屑病患者活检组织与健康志愿者相比Trim33的基因表达。使用免疫沉淀结合质谱法鉴定Trim33底物。通过免疫印迹和免疫荧光评估蛋白质表达和定位。用qPCR分析细胞因子的表达。
qPCR和IF分析显示银屑病表皮中Trim33表达增加。Trim33的过表达促进了银屑病相关促炎细胞因子IL-6、IL-1β和NLRP3炎性小体的表达。有趣的是，Trim33诱导膜联蛋白A2（Anxa2）的赖氨酸63（K63）连接的泛素化，这促进了其与NF-κB的p50/p65亚基的相互作用，有利于p50/p65在细胞核中的保留，并促进炎症相关NF-κB下游基因的表达。
我们的研究强调了Trim33在银屑病表皮中的上调及其通过Anxa2/NF-κB途径促进角质形成细胞炎症的关键作用。我们的发现意味着Trim33可能作为银屑病治疗的潜在靶点被进一步探索。
