BACKGROUND MiR-27 has been found to present an overt myocardial expression during cardiogenesis. However, whether miR-27 involves in myocarditis development and the possible molecular mechanism remain unknown. The purpose of this study was to investigate the biological characteristic of miR-27 in LPS-damaged H9c2 cells. METHODS H9c2 cells were treated with lipopolysaccharide (LPS, 10 µg/ml) for 12 h to form cell injury. MiR-27 mimic and inhibitor were used to up-regulate or down-regulate miR-27 expression. MTT assay and flow cytometry analysis were conducted to test cell viability and apoptosis. The relative RNA expression level of miR-27 and intercellular adhesion molecule 1 (ICAM1) was determined by qRT-PCR. Luciferase reporter gene assay was utilized to confirm the interaction between miR-27 and ICAM1. Western blot was used to determine the protein expression levels. RESULTS We observed that LPS treatment significantly decreased the level of miR-27 in H9c2 cells. Moreover, LPS exposure suppressed cell viability, promoted cell apoptosis and increased the relative expression of p-NF-κB p65/NF-κB p65 and p-IκBα/IκBα. Up-regulation of miR-27 increased cell proliferation and reduced cell apoptosis, while down-regulation of miR-27 suppressed cell growth and promoted cell apoptosis. ICAM1 was predicted and verified as a target of miR-27, and the expression of ICAM1 is negatively regulated by miR-27. The relative expression of p-NF-κB p65/NF-κB p65 and p-IκBα/IκBα was dramatically decreased by miR-27 mimic and increased by miR-27 inhibitor. CONCLUSION Our study illustrated that up-regulation of miR-27 exhibits a protective effect on LPS-damaged H9c2 cells, which may be achieved by regulating ICAM1 and NF-κB signaling.

中文翻译：

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miR-27的上调通过调节ICAM1表达减轻H9c2细胞中脂多糖诱导的损伤。

背景技术已经发现MiR-27在心脏发生过程中表现出明显的心肌表达。但是，miR-27是否参与心肌炎的发展以及可能的分子机制仍不清楚。本研究的目的是研究miR-27在LPS损伤的H9c2细胞中的生物学特性。方法用脂多糖（LPS，10 µg / ml）处理H9c2细胞12小时，以形成细胞损伤。使用MiR-27模拟物和抑制剂来上调或下调miR-27的表达。进行MTT测定和流式细胞仪分析以测试细胞活力和凋亡。通过qRT-PCR确定miR-27和细胞间粘附分子1（ICAM1）的相对RNA表达水平。萤光素酶报告基因检测用于证实miR-27和ICAM1之间的相互作用。蛋白质印迹用于确定蛋白质表达水平。结果我们观察到LPS处理可显着降低H9c2细胞中miR-27的水平。此外，LPS暴露抑制细胞活力，促进细胞凋亡并增加p-NF-κBp65 /NF-κBp65和p-IκBα/IκBα的相对表达。miR-27的上调可增加细胞增殖并减少细胞凋亡，而miR-27的下调可抑制细胞生长并促进细胞凋亡。预测并证实ICAM1是miR-27的靶标，而miR-27对ICAM1的表达负调控。miR-27模拟显着降低了p-NF-κBp65 /NF-κBp65和p-IκBα/IκBα的相对表达，而miR-27抑制剂则使相对表达增加。