Chen Zhi, Dong Wei-Hua, Wu Qi, Wang Jun
Department of Critical Care Medicine, Jiangxi Provincial People's Hospital Affiliated to Nanchang University Nanchang, Jiangxi, China.
Department of General Surgery, Jiangxi Provincial People's Hospital Affiliated to Nanchang University Nanchang, Jiangxi, China.
Am J Transl Res. 2020 Jun 15;12(6):2379-2395. eCollection 2020.
Inflammation is a leading cause of severe acute pancreatitis (SAP). MicroRNAs (miRNAs) are emerging as important regulators involved in the pathogenesis of many diseases including pancreatitis. To identify miRNAs that contribute to the pathology of SAP, we carried out a miRNA-specific microarray analysis using the biopsies donated by SAP patients. We totally obtained 50 differentially expressed miRNAs, including 20 upregulated and 30 downregulated miRNAs, respectively. We focused our current study on revealing the downstream target and the upstream regulatory mechanism of miR-589-5p, the most downregulated miRNA in our candidate lists. Our prediction results indicated that miR-589-5p might target (tumor necrosis factor receptor-associated factor 6), a critical member of the TLR4/NF-kB (Toll-like receptor 4/nuclear transcription factor-kB) pathway. Using different strategies such as overexpression or downregulation of miR-589-5p and treatment with lipopolysaccharide (LPS), we found that the expression of was regulated by two-layer mechanisms. On the one hand, was transcriptionally controlled by a DNA methylation mediated downregulation of miR-589-5p. On the other hand, the activation of TLR4/NF-kB signaling also could increase the protein level of TRAF6. The increased TRAF6 aggravated the downstream signaling and caused the translocation of NF-kB subunits from the cytoplasm to the nucleus, where NF-kB transcription factors induced the expression of proinflammatory cytokine genes. The maturation and production of proinflammatory cytokines induced inflammatory response and caused the occurrence of SAP.
炎症是重症急性胰腺炎（SAP）的主要病因。微小RNA（miRNA）正逐渐成为参与包括胰腺炎在内的多种疾病发病机制的重要调节因子。为了鉴定促成SAP病理过程的miRNA，我们使用SAP患者捐赠的活检组织进行了miRNA特异性微阵列分析。我们总共获得了50个差异表达的miRNA，其中分别有20个上调和30个下调的miRNA。我们当前的研究重点是揭示候选列表中下调最明显的miR-589-5p的下游靶点和上游调控机制。我们的预测结果表明，miR-589-5p可能靶向肿瘤坏死因子受体相关因子6（TRAF6），它是Toll样受体4/核转录因子-κB（TLR4/NF-κB）通路的关键成员。通过使用不同策略，如miR-589-5p的过表达或下调以及用脂多糖（LPS）处理，我们发现TRAF6的表达受两层机制调控。一方面，TRAF6受到DNA甲基化介导的miR-589-5p下调的转录控制。另一方面，TLR4/NF-κB信号的激活也可增加TRAF6的蛋白水平。增加的TRAF6加剧了下游信号传导，并导致NF-κB亚基从细胞质转运至细胞核，在细胞核中NF-κB转录因子诱导促炎细胞因子基因的表达。促炎细胞因子的成熟和产生引发炎症反应并导致SAP的发生。
