Chen Weiwei, Ma Xiaoying, Zhang Peng, Li Qifeng, Liang Xin, Liu Jianwen
State Key Laboratory of Bioreactor Engineering & Shanghai Key Laboratory of New Drug Design, School of pharmacy, East China University of Science and Technology, Shanghai, PR China.
Department of Pediatric Neurosurgery, Xinhua Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai 200092, PR China.
Exp Cell Res. 2017 Jan 15;350(2):318-326. doi: 10.1016/j.yexcr.2016.12.008. Epub 2016 Dec 8.
Sepsis is a major cause of mortality in seriously ill patients characterized by a series of severe systemic inflammatory responses due to an infection. Thus, there is a critically need to search more accurate biomarkers and targets for diagnosis and treatment of sepsis. Our study showed that miR-212-3p was up-regulated in LPS-treated macrophage RAW264.7 cells. Overexpression of miR-212-3p in RAW264.7 cells led to suppression of pro-inflammatory cytokines (TNF-α and IL-6) induced by LPS. Bioinformatic predictions and experimental researches both revealed that HMGB1 was a direct target of miR-212-3p. Meanwhile, the results showed that overexpression of miR-212-3p inhibited the cytoplasmic translocation of HMGB1 in LPS-induced RAW264.7 cells. Subsequently, transfection of the pcDNA3.1/HMGB1 plasmid, which produced HMGB1 overexpression, exhibited similar effects as the LPS-induced macrophage inflammatory response and markedly activated the MAPKs including p38, ERK and JNK phosphorylation. Furthermore, we also found that the phosphorylation of p38 MAPK and ERK was downregulated by miR-212-3p mimics upon LPS injection. In conclusion, these results reveal that miR-212-3p directly targets HMGB1 to suppress inflammatory response in LPS-induced RAW264.7 cells. All our findings indicate that miR-212-3p may act as a potential pharmacological target for promising and effective therapeutic intervention in microbial infection in the future.
脓毒症是重症患者死亡的主要原因，其特征是由于感染引发一系列严重的全身炎症反应。因此，迫切需要寻找更准确的生物标志物和靶点用于脓毒症的诊断和治疗。我们的研究表明，在经脂多糖（LPS）处理的巨噬细胞RAW264.7细胞中，miR-212-3p上调。RAW264.7细胞中miR-212-3p的过表达导致LPS诱导的促炎细胞因子（肿瘤坏死因子-α和白细胞介素-6）受到抑制。生物信息学预测和实验研究均表明，高迁移率族蛋白B1（HMGB1）是miR-212-3p的直接靶点。同时，结果显示miR-212-3p的过表达抑制了LPS诱导的RAW264.7细胞中HMGB1的细胞质转位。随后，转染产生HMGB1过表达的pcDNA3.1/HMGB1质粒，表现出与LPS诱导的巨噬细胞炎症反应相似的效果，并显著激活包括p38、细胞外信号调节激酶（ERK）和c-Jun氨基末端激酶（JNK）磷酸化在内的丝裂原活化蛋白激酶（MAPK）。此外，我们还发现，注射LPS后，miR-212-3p模拟物可下调p38 MAPK和ERK的磷酸化。总之，这些结果表明，miR-212-3p直接靶向HMGB1以抑制LPS诱导的RAW264.7细胞中的炎症反应。我们所有的研究结果表明，miR-212-3p可能作为未来微生物感染中有前景且有效的治疗干预的潜在药理学靶点。
