Intervening upregulated SLC7A5 could mitigate inflammatory mediator by mTOR-P70S6K signal in rheumatoid arthritis synoviocytes
Intervening upregulated SLC7A5 could mitigate inflammatory mediator by mTOR-P70S6K signal in rheumatoid arthritis synoviocytes
复制标题
干预上调的 SLC7A5 可以通过 mTOR-P70S6K 信号减轻类风湿性关节炎滑膜细胞中的炎症介质
DOI：
10.1186/s13075-020-02296-8
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发表时间：
2020
影响因子：
4.9
通讯作者：
Lu Shemin
中科院分区：
文献类型：
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作者：
Xu Jing;Jiang Congshan;Cai Yongsong;Guo Yuanxu;Wang Xipeng;Zhang Jiaxiang;Xu Jiawen;Xu Ke;Zhu Wenhua;Wang Si;Zhang Fujun;Geng Manman;Han Yan;Ning Qilan;Xu Peng;Meng Liesu;Lu Shemin
目的 RA 中持续炎症导致代谢事件的破坏以及营养物和氧气可用性的变化，增加了受损组织内生物能和生物合成过程的需求。本研究旨在了解RA患者滑膜细胞中SLC7A5（氨基酸转运蛋白）的分子机制。方法取OA和RA患者的滑膜组织。分离成纤维细胞样滑膜细胞 (FLS)，并使用 RT-qPCR、免疫荧光和蛋白质印迹检查 SLC7A5 表达。 RNAi 和抗体阻断治疗用于敲低 SLC7A5 表达或阻断其转运蛋白活性。在氨基酸剥夺或营养丰富的条件下监测RA FLS中的mTOR活性测定和MMP表达水平。结果与OA FLS相比，RA FLS显示SLC7A5的表达显着上调。研究发现细胞因子 IL-1β 在通过 NF-κB 途径上调 SLC7A5 表达中发挥着至关重要的作用。通过 RNAi 干预 SLC7A5 表达或通过单克隆抗体阻断其功能可改善 MMP3 和 MMP13 蛋白表达。相反，上调SLC7A5或补充色氨酸增强mTOR-P70S6K信号，促进RA FLS中MMP3和MMP13的蛋白翻译。结论激活的NF-κB通路上调SLC7A5，从而增强RA FLS中mTOR-P70S6K活性以及MMP3和MMP13表达。
ObjectiveThe disruption of metabolic events and changes to nutrient and oxygen availability due to sustained inflammation in RA increases the demand of bioenergetic and biosynthetic processes within the damaged tissue. The current study aimed to understand the molecular mechanisms of SLC7A5 (amino acid transporter) in synoviocytes of RA patients.MethodsSynovial tissues were obtained from OA and RA patients. Fibroblast-like synoviocytes (FLS) were isolated, and SLC7A5 expression was examined by using RT-qPCR, immunofluorescence, and Western blotting. RNAi and antibody blocking treatments were used to knockdown SLC7A5 expression or to block its transporter activities. mTOR activity assay and MMP expression levels were monitored in RA FLS under amino acid deprivation or nutrient-rich conditions.ResultsRA FLS displayed significantly upregulated expression of SLC7A5 compared to OA FLS. Cytokine IL-1β was found to play a crucial role in upregulating SLC7A5 expression via the NF-κB pathway. Intervening SLC7A5 expression with RNAi or blocking its function by monoclonal antibody ameliorated MMP3 and MMP13 protein expression. Conversely, upregulation of SLC7A5 or tryptophan supplementation enhanced mTOR-P70S6K signals which promoted the protein translation of MMP3 and MMP13 in RA FLS.ConclusionActivated NF-κB pathway upregulates SLC7A5, which enhances the mTOR-P70S6K activity and MMP3 and MMP13 expression in RA FLS.