Department of Food and Nutrition, Eulji University, Seongnam 13135, Korea.
Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon 21999, Korea.
Molecules. 2019 Apr 10;24(7):1410. doi: 10.3390/molecules24071410.
We have previously reported that long-term treatment of beta cells with interleukin-6 (IL-6) is pro-apoptotic. However, little is known about the regulatory mechanisms that are involved. Therefore, we investigated pro-apoptotic changes in mRNA expression in beta cells in response to IL-6 treatment. We analyzed a microarray with RNA from INS-1 beta cells treated with IL-6, and found that TNF-α mRNA was significantly upregulated. Inhibition of TNF-α expression by neutralizing antibodies significantly decreased annexin V staining in cells compared with those treated with a control antibody. We identified three microRNAs that were differentially expressed in INS-1 cells incubated with IL-6. In particular, miR-181c was significantly downregulated in IL-6-treated cells compared with control cells and the decrease of miR-181c was attenuated by STAT-3 signaling inhibition. TNF-α mRNA was a direct target of miR-181c and upregulation of miR-181c by mimics, inhibited IL-6-induced increase in TNF-α mRNA expression. Consequently, reduction of TNF-α mRNA caused by miR-181c mimics enhanced cell viability in IL-6 treated INS-1 cells. These results demonstrated that miR-181c regulation of TNF-α expression plays a role in IL-6-induced beta cell apoptosis.
我们之前曾报道，白细胞介素-6（IL-6）长期作用于β细胞会导致细胞凋亡。然而，目前对于涉及的调节机制知之甚少。因此，我们研究了β细胞中对 IL-6 处理的促凋亡变化的 mRNA 表达。我们分析了 INS-1β细胞用 IL-6 处理的 RNA 的微阵列，发现 TNF-α mRNA 显著上调。与用对照抗体处理的细胞相比，用中和抗体抑制 TNF-α表达可显著减少细胞的膜联蛋白 V 染色。我们在用 IL-6 孵育的 INS-1 细胞中鉴定出三种差异表达的 microRNA。特别是，miR-181c 在 IL-6 处理的细胞中与对照细胞相比显著下调，并且 STAT-3 信号抑制减弱了 miR-181c 的减少。TNF-α mRNA 是 miR-181c 的直接靶标，miR-181c 模拟物的上调抑制了 IL-6 诱导的 TNF-α mRNA 表达增加。因此，miR-181c 模拟物对 TNF-α mRNA 的减少导致 IL-6 处理的 INS-1 细胞中的细胞活力增强。这些结果表明，miR-181c 对 TNF-α 表达的调节在 IL-6 诱导的β细胞凋亡中起作用。
