Brucella Downregulates Tumor Necrosis Factor-α to Promote Intracellular Survival via Omp25 Regulation of Different MicroRNAs in Porcine and Murine Macrophages.
Brucella Downregulates Tumor Necrosis Factor-α to Promote Intracellular Survival via Omp25 Regulation of Different MicroRNAs in Porcine and Murine Macrophages.
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布鲁氏菌通过 Omp25 调节猪和鼠巨噬细胞中不同的 MicroRNA 下调肿瘤坏死因子-α 以促进细胞内存活
DOI：
10.3389/fimmu.2017.02013
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发表时间：
2017
影响因子：
7.3
通讯作者：
Huang Y
中科院分区：
文献类型：
--
作者：
Luo X;Zhang X;Wu X;Yang X;Han C;Wang Z;Du Q;Zhao X;Liu SL;Tong D;Huang Y
布鲁氏菌通过其外膜蛋白Omp 25阻碍促炎细胞因子的产生，以促进存活和免疫逃避。然而，Omp 25如何调节肿瘤坏死因子（TNF-α）在不同哺乳动物巨噬细胞中的表达仍不清楚。在本研究中，我们研究了Omp 25调节TNF-α表达的潜在机制，发现Omp 25缺陷型B.与野生型（WT）B相比，猪的TNF-α表达增强。猪肺泡巨噬细胞（PAM）和小鼠巨噬细胞RAW264.7细胞中Omp 25的异位表达在蛋白和mRNA水平上抑制LPS诱导的TNF-α的产生。我们观察到Omp 25蛋白以及WT B.在PAM和RAW264.7细胞中，suis上调miR-146 a、-181 a、-181 b和-301 a-3p，下调TRAF 6和IRAK 1，但分别上调PAM中的miR-130 a-3 p和RAW264.7中的miR-351- 5 p。miR-146 a或miR-351- 5 p的上调通过靶向TRAF 6和IRAK 1的3′非翻译区（UTR）来减弱TNF-α的转录，导致NF-κ B通路的抑制，而miR-130 a-3 p、-181a或-301a-3p的上调通过靶向PAM或RAW 264.7细胞中的TNF-α的3′UTR来与TNF-α的减少暂时相关。相比之下，抑制miR-130 a-3 p、-146 a、-181 a和-301 a-3 p减弱了Omp 25对PAM中LPS诱导的TNF-α的抑制作用，而抑制miR-146 a、-181 a、-301 a-3 p和-351-5p减弱了Omp 25对RAW 264.7中LPS诱导的TNF-α的抑制作用。导致两种细胞中TNF-α产生增加和细胞内细菌减少。综上所述，我们的研究结果表明，布鲁氏菌下调TNF-α，以促进细胞内的生存通过Omp 25调节不同的microRNA在猪和小鼠巨噬细胞。
Brucella spp. impedes the production of pro-inflammatory cytokines by its outer membrane protein Omp25 in order to promote survival and immune evasion. However, how Omp25 regulates tumor necrosis factor (TNF-α) expression in different mammalian macrophages remains unclear. In this study, we investigated the potential mechanisms by which Omp25 regulates TNF-α expression and found that Omp25-deficient mutant of B. suis exhibited an enhanced TNF-α expression compared with wild-type (WT) B. suis, whereas ectopic expression of Omp25 suppressed LPS-induced TNF-α production at both protein and mRNA levels in porcine alveolar macrophages (PAMs) and murine macrophage RAW264.7 cells. We observed that Omp25 protein as well as WT B. suis upregulated miR-146a, -181a, -181b, and -301a-3p and downregulated TRAF6 and IRAK1 in both PAMs and RAW264.7 cells, but separately upregulates miR-130a-3p in PAMs and miR-351-5p in RAW264.7. The upregulation of miR-146a or miR-351-5p attenuated TNF-α transcription by targeting TRAF6 and IRAK1 at the 3′ untranslated region (UTR), resulting in inhibition of NF-kB pathway, while upregulation of miR-130a-3p, -181a, or -301a-3p correlated temporally with decreased TNF-α by targeting its 3′UTR in PAMs or RAW264.7 cells. In contrast, inhibition of miR-130a-3p, -146a, -181a, and -301a-3p attenuated the inhibitory effects of Omp25 on LPS-induced TNF-α in PAMs, while inhibition of miR-146a, -181a, -301a-3p, and -351-5p attenuated the inhibitory effects of Omp25 in RAW264.7, resulting in an increased TNF-α production and decreased intracellular bacteria in both cells. Taken together, our results demonstrate that Brucella downregulates TNF-α to promote intracellular survival via Omp25 regulation of different microRNAs in porcine and murine macrophages.