Huang Jian, Jiao Junhua, Xu Weihua, Zhao Huayang, Zhang Chunxiao, Shi Yan, Xiao Zhijian
Second Tuberculosis Internal Medicine Department, The First Affiliated Hospital of Xinxiang Medical University, Weihui, Henan 453100, P.R. China.
First Tuberculosis Internal Medicine Department, The First Affiliated Hospital of Xinxiang Medical University, Weihui, Henan 453100, P.R. China.
Mol Med Rep. 2015 Nov;12(5):7102-8. doi: 10.3892/mmr.2015.4250. Epub 2015 Aug 25.
The aim of the present study was to investigate the association between microRNA (miR)-155 and apoptosis of monocytes infected by Mycobacterium tuberculosis, to examine the effect of forkhead box O3 (FOXO3) on miR‑155. The present study analysed the apoptosis of CD14+ in the peripheral blood of patients with active tuberculosis, disposed the THP‑1 human monocytic cell line by BCG and examined the expression of miR‑155. Furthermore, the expression of FOXO3 in THP‑1 cells was determined, and wild- and mutant-type luciferase reporter plasmids containing FOXO3 3'‑untranslated regions (UTRs) were constructed to analyse the expression of luciferase. Finally, an over‑expression plasmid was constructed, and THP-1 cells were transfected with control miRNA, miR‑155 and the plasmid, which revealed that miR‑155 inhibited the apoptosis of THP‑1 cells. miR‑155 in the THP‑1 cells infected by BCG was upregulated and apoptosis also increased. However, the apoptosis declined when the cells were transfected with the control miRNA and miR‑155. Folllowing transfection with miR‑155, the expression of FOXO3 decreased. Transfection with miR‑155 and the FOXO3 3'-UTRs significantly reduced luciferase, and overexpression of FOXO3 reversed the inhibitory role of miR‑155. From these results, it was concluded that mycobacteria can improve the level of miR‑155, while BCG can induce apoptosis in THP‑1 cells. The results suggested FOXO3 is a downstream target gene of miR‑155, which combines 3'-UTRs to inhibit the expression of FOXO3.
本研究的目的是探讨微小RNA（miR）-155与结核分枝杆菌感染的单核细胞凋亡之间的关联，研究叉头框O3（FOXO3）对miR-155的影响。本研究分析了活动性肺结核患者外周血中CD14+细胞的凋亡情况，用卡介苗处理THP-1人单核细胞系并检测miR-155的表达。此外，测定了THP-1细胞中FOXO3的表达，构建了包含FOXO3 3'非翻译区（UTR）的野生型和突变型荧光素酶报告质粒以分析荧光素酶的表达。最后，构建了过表达质粒，用对照miRNA、miR-155和该质粒转染THP-1细胞，结果显示miR-155抑制THP-1细胞凋亡。卡介苗感染的THP-1细胞中miR-155上调且凋亡也增加。然而，用对照miRNA和miR-155转染细胞后凋亡减少。转染miR-155后，FOXO3的表达降低。转染miR-155和FOXO3 3'-UTR显著降低荧光素酶活性，FOXO3过表达逆转了miR-155的抑制作用。从这些结果得出结论，分枝杆菌可提高miR-155水平，而卡介苗可诱导THP-1细胞凋亡。结果表明FOXO3是miR-155的下游靶基因，其与3'-UTR结合抑制FOXO3的表达。
