Royal College of Surgeons in Ireland, Dublin, Ireland.
Arthritis Rheumatol. 2014 Jan;66(1):163-72. doi: 10.1002/art.38187.
To examine the role of 17β-estradiol in the regulation of the autoantigen tripartite motif-containing protein 21 (TRIM-21) in patients with systemic lupus erythematosus (SLE).
Monocytes isolated from healthy control subjects and patients with SLE were stimulated with 17β-estradiol and/or the estrogen receptor α (ERα) antagonist methyl-piperidino-pyrazole dihydrochloride. TRIM-21, ERα, and CREMα expression was determined by real-time polymerase chain reaction (PCR) analysis. MatInspector software was used to identify putative binding sites within the TRIM-21 promoter. ERα binding to the TRIM-21 gene promoter region in monocytes was analyzed by chromatin immunoprecipitation (ChIP) assay. TRIM-21 and interferon regulatory factor 3 protein levels were analyzed by Western blotting.
Real-time PCR analysis demonstrated a role of estrogen in the regulation of TRIM-21 expression in monocytes, which correlated positively with ERα gene expression in patients with SLE. Investigations into the human TRIM-21 promoter revealed the presence of an estrogen response element, with ChIP assays confirming ERα binding to this site. Studies into estrogen-induced TRIM-21 expression revealed a hyperresponsiveness of SLE patients to 17β-estradiol, which led to the enhanced levels of TRIM-21 observed in these individuals.
Our results demonstrate a role of estrogen in the regulation of TRIM-21 expression through an ERα-dependent mechanism, a pathway that we observed to be overactive in SLE patients. Treatment of monocytes with an ERα antagonist abrogated estrogen-induced TRIM-21 expression and, as a consequence, decreased the expression of interleukin-23. These findings identify TRIM-21 as a novel ERα-regulated gene and provide novel insights into the link between estrogen and the molecular pathogenesis of SLE.
探讨 17β-雌二醇在调节系统性红斑狼疮（SLE）患者自身抗原三结构域蛋白 21（TRIM-21）中的作用。
用 17β-雌二醇和/或雌激素受体α（ERα）拮抗剂甲哌啶基吡唑二盐酸盐刺激来自健康对照者和 SLE 患者的单核细胞。通过实时聚合酶链反应（PCR）分析测定 TRIM-21、ERα 和 CREMα 的表达。使用 MatInspector 软件鉴定 TRIM-21 启动子内的潜在结合位点。通过染色质免疫沉淀（ChIP）分析检测 ERα 与单核细胞中 TRIM-21 基因启动子区的结合。通过 Western 印迹分析 TRIM-21 和干扰素调节因子 3 蛋白水平。
实时 PCR 分析表明，雌激素在调节单核细胞中 TRIM-21 的表达中起作用，这与 SLE 患者中 ERα 基因表达呈正相关。对人 TRIM-21 启动子的研究表明存在雌激素反应元件，ChIP 实验证实 ERα 与该位点结合。对雌激素诱导的 TRIM-21 表达研究表明，SLE 患者对 17β-雌二醇的反应过度，导致这些个体中观察到的 TRIM-21 水平升高。
我们的结果表明，雌激素通过 ERα 依赖性机制调节 TRIM-21 的表达，我们观察到该途径在 SLE 患者中过度活跃。用 ERα 拮抗剂处理单核细胞可阻断雌激素诱导的 TRIM-21 表达，并因此降低白细胞介素-23 的表达。这些发现确定 TRIM-21 为一种新的 ERα 调节基因，并为雌激素与 SLE 分子发病机制之间的联系提供了新的见解。
