Acute pancreatitis (AP), a sudden inflammatory process of pancreas, is painful and may contribute to death. The aberrant expression of miR-27a-5p has been reported in many types of cancers and diseases including AP. Thus, it is urgent to manifest the functions and mechanism of miR-27a-5p in AP. The levels of miR-27a-5p, tumor necrosis factor (TNF) receptor–associated factor 3 (Traf3) in serum of AP patient, or cerulein-treated AR42J cells were detected by qRT-PCR. Functionally, the apoptotic rate, the protein levels of Bcl-2 and Bax, the caspase-3 activity, and the levels of IL-1β, IL-6, and TNF-α in cerulein-treated AR42J cells were measured by flow cytometry, Western blot, caspase-3 activity assay, and qRT-PCR and ELISA assay, respectively. In addition, the putative target of miR-27a-5p was predicted by TargetScan online database, and the dual luciferase reporter assay and RNA immunoprecipitation (RIP) assay were conducted to verify this interaction. Cerulein-treated mouse AP model was established to explore the role of miR-27a-5p in AP in vivo. The level of miR-27a-5p was notably downregulated in AP patients and cerulein-treated AR42J cells. The functional experiments indicated that miR-27a-5p mimics attenuated the promotion effects on cell apoptosis and the inflammatory response in AR42J cells caused by cerulein. The interaction between miR-27a-5p and Traf3 was predicted by TargetScan online database and validated by dual luciferase reporter assay and RIP assay. Following qRT-PCR results exhibited that Traf3 was apparently enhanced in cerulein-treated AR42J cells. The further functional experiments disclosed that Traf3 overexpression relieved the inhibitory effects on cell apoptosis and the inflammatory response induced by miR-27a-5p mimics in cerulein-treated AR42J cells. Moreover, miR-27a-5p alleviated cerulein-induced injury in vivo. In this study, we established the cerulein-treated AR42J cells as AP model in vitro. We validated that miR-27a-5p was significantly downregulated, and Traf3 was strikingly upregulated in AP patient and/or cerulein-treated AR42J cells. The further mechanistical and functional experiments unraveled that miR-27a-5p regulated Traf3 to relieve the cerulein-induced cell apoptosis and inflammatory injury of AR42J cells. Therefore, this novel regulatory network may provide therapeutic target for AP patients.

急性胰腺炎（AP）是胰腺的突然发炎过程，很痛苦，可能导致死亡。已经报道了许多类型的癌症和疾病，包括AP，miR-27a-5p的异常表达。因此，迫切需要在AP中体现miR-27a-5p的功能和机制。通过qRT-PCR检测AP患者血清或经青霉素处理的AR42J细胞中miR-27a-5p，肿瘤坏死因子（TNF）受体相关因子3（Traf3）的水平。在功能上，通过流式细胞仪测量凋亡的速度，Bcl-2和Bax的蛋白质水平，caspase-3活性以及青霉素处理过的AR42J细胞中IL-1β，IL-6和TNF-α的水平，分别进行蛋白质印迹，caspase-3活性测定，qRT-PCR和ELISA测定。此外，通过TargetScan在线数据库预测了miR-27a-5p的推定靶标，并进行了双重荧光素酶报告基因分析和RNA免疫沉淀（RIP）分析，以验证这种相互作用。建立了用Cerulein治疗的小鼠AP模型，以探索miR-27a-5p在AP中的作用体内。在AP患者和青霉素治疗的AR42J细胞中，miR-27a-5p的水平明显下调。功能实验表明，miR-27a-5p模拟物减弱了由轻蓝素引起的促进细胞凋亡和AR42J细胞炎症反应的作用。通过TargetScan在线数据库预测了miR-27a-5p与Traf3之间的相互作用，并通过双重萤光素酶报告基因分析和RIP分析进行了验证。根据qRT-PCR结果显示，Traf3在经青霉素处理的AR42J细胞中明显增强。进一步的功能性实验表明，Traf3的过表达减轻了miR-27a-5p模拟物在青霉素处理过的AR42J细胞中对细胞凋亡和炎症反应的抑制作用。此外，miR-27a-5p减轻了轻蓝素诱导的体内损伤。在这项研究中，我们建立了经铜蓝蛋白处理的AR42J细胞作为AP模型的体外实验。我们验证了在AP患者和/或经青霉素治疗的AR42J细胞中，miR-27a-5p显着下调，并且Traf3显着上调。进一步的机理和功能实验表明，miR-27a-5p调节Traf3以减轻青霉素诱导的AR42J细胞凋亡和炎症损伤。因此，这种新颖的调节网络可以为AP患者提供治疗目标。