Cheng Xiuqin, Zhang Xiaofei, Su Jiewen, Zhang Yingdi, Zhou Weimei, Zhou Jun, Wang Cheng, Liang Hongwei, Chen Xi, Shi Ruihua, Zen Ke, Zhang Chen-Yu, Zhang Hongjie
Department of Gastroenterology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China.
1] Department of Gastroenterology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China [2] Department of Gastroenterology, Laigang Hospital Affiliated to Taishan Medical University,Laiwu, Shandong 271000, China.
Sci Rep. 2015 May 22;5:10397. doi: 10.1038/srep10397.
Although aberrant microRNA (miRNA) expression has frequently been observed in inflammatory bowel disease (IBD), its biological functions and targets remain largely unknown. Present study found that miR-19b was significantly downregulated in active Crohn's disease (CD). Using bioinformatics analysis, suppressor of cytokine signalling 3 (SOCS3), a physiological regulator of innate and adaptive immunity that controls several immuno-inflammatory diseases, was predicted to be a potential target of miR-19b. An inverse correlation between miR-19b and SOCS3 protein levels, but not mRNA, was identified in active-CD intestinal tissue samples. By overexpressing or knocking down miR-19b in Caco2 cells and HT29 cells, it was experimentally validated that miR-19b is a direct regulator of SOCS3. Using a luciferase reporter assay, it was confirmed that miR-19b directly recognizes the 3'-untranslated region (3'-UTR) of SOCS3. Furthermore, overexpression of miR-19b decreased SOCS3 expression, leading to increased production of macrophage-inflammatory protein-3α (MIP-3α) in Caco2 cells. In contrast, knockdown of miR-19b increased SOCS3 and decreased MIP-3α. Finally, intracolonically delivered miR-19b decreased the severity of colitis induced with 2,4,6-trinitrobenzene sulphonic acid (TNBS). Taken together, our findings suggest that miR-19b suppresses the inflammatory response by inhibiting SOCS3 to modulate chemokine production in intestinal epithelial cells (IECs) and thereby prevents the pathogenesis of CD.
尽管在炎症性肠病（IBD）中经常观察到异常的微小RNA（miRNA）表达，但其生物学功能和靶标仍 largely 未知。目前的研究发现，miR-19b在活动性克罗恩病（CD）中显著下调。通过生物信息学分析，细胞因子信号转导抑制因子3（SOCS3），一种控制多种免疫炎症性疾病的先天性和适应性免疫的生理调节因子，被预测为miR-19b的潜在靶标。在活动性CD肠道组织样本中，miR-19b与SOCS3蛋白水平而非mRNA之间存在负相关。通过在Caco2细胞和HT29细胞中过表达或敲低miR-19b，实验验证了miR-19b是SOCS3的直接调节因子。使用荧光素酶报告基因测定法，证实miR-19b直接识别SOCS3的3'非翻译区（3'-UTR）。此外，miR-19b的过表达降低了SOCS3的表达，导致Caco2细胞中巨噬细胞炎性蛋白-3α（MIP-3α）的产生增加。相反，miR-19b的敲低增加了SOCS3并降低了MIP-3α。最后，结肠内递送miR-19b降低了2,4,6-三硝基苯磺酸（TNBS）诱导的结肠炎的严重程度。综上所述，我们的研究结果表明，miR-19b通过抑制SOCS3来调节肠道上皮细胞（IECs）中的趋化因子产生，从而抑制炎症反应，进而预防CD的发病机制。
