Objective

This study is to identify the effects of miRNA-140-5p on necrotizing pneumonia (NP) and its underlying mechanism.

Methods

The mRNA levels of miRNA-140-5p and TLR4 and secretion of IL-1β, IL-6, and TNF-α in peripheral blood from children with NP and healthy volunteers were determined using qRT-PCR and specific ELISAs. The interactions between miRNA-140-5p and TLR4 were investigated using a dual-luciferase reporter system. Cell viabilities were determined using a CCK-8 assay. qRT-PCR, western blotting, and specific ELISAs were applied to determine the expressions of genes in the cells. Peripheral blood from children with NP had significantly elevated levels of TLR4 but significantly lower levels of miR-140-5p compared to the control.

Results

Spearman’s rank correlation analysis showed a negative correlation between TLR4 and miR-140-5p. miR-140-5p regulated the expressions of TLR4 in A549 cells. Additionally, LPS induced a significant enhancement in the levels of TLR4 but significant reduction in the levels of miR-140-5p. The overexpression of miR-140-5p suppressed cell apoptosis and induced the release of inflammatory cytokines in the LPS-induced A549 cells.

Conclusion

The underlying mechanisms of miR-140-5p on the regulation of TLR4 are in part by the regulation of p65. The miR-140-5p inhibits necrotizing pneumonia by regulating TLR-4 via TNF–p65 signaling pathway.

中文翻译：

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miR-140-5p 过表达通过靶向 Toll 样受体 4 预防脂多糖诱导的坏死性肺炎

客观的

本研究旨在确定 miRNA-140-5p 对坏死性肺炎 (NP) 的影响及其潜在机制。

方法

使用 qRT-PCR 和特异性 ELISA 测定 NP 儿童和健康志愿者外周血中 miRNA-140-5p 和 TLR4 的 mRNA 水平以及 IL-1β、IL-6 和 TNF-α 的分泌。使用双荧光素酶报告系统研究 miRNA-140-5p 和 TLR4 之间的相互作用。使用 CCK-8 测定法测定细胞活力。应用 qRT-PCR、蛋白质印迹和特异性 ELISA 来确定细胞中基因的表达。与对照组相比，患有 NP 的儿童的外周血 TLR4 水平显着升高，但 miR-140-5p 水平显着降低。

结果

Spearman 秩相关分析显示 TLR4 与 miR-140-5p 呈负相关。miR-140-5p 调节 A549 细胞中 TLR4 的表达。此外，LPS 诱导 TLR4 水平显着增强，但 miR-140-5p 水平显着降低。miR-140-5p的过表达抑制细胞凋亡并诱导LPS诱导的A549细胞中炎性细胞因子的释放。

结论

miR-140-5p 调节 TLR4 的潜在机制部分是通过 p65 的调节。miR-140-5p 通过 TNF-p65 信号通路调节 TLR-4 来抑制坏死性肺炎。