Department of laboratory, Changsha Central Hospital Affiliated to Nanhua University, 410004, China.
Department of laboratory, Changsha Central Hospital Affiliated to Nanhua University, 410004, China.
Microb Pathog. 2022 Aug;169:105609. doi: 10.1016/j.micpath.2022.105609. Epub 2022 Jun 3.
Impaired autophagy is an important cause of Mycobacterium tuberculosis survival in macrophages. VPS11 is an important regulator of autophagy; decreased VPS11 expression has been observed in macrophages after tuberculosis (TB) infection. Gene ontology data revealed that various miRNAs (for example, miR-542-3p) were upregulated in macrophages upon TB infection; thus, these miRNAs were likely to reduce VPS11 expression. In this study, both TB patients and healthy subjects were enrolled, and the levels of VPS11 and some miRNAs in their blood macrophages were measured. Moreover, various macrophages were cultured and infected with M. tuberculosis. Luciferase reporter, RNA pulldown, and RNA immunoprecipitation assays were performed to determine the regulatory effect of miR-542-3p on VPS11 expression. Results showed that VPS11 expression was downregulated, whereas miR-542-3p expression was upregulated in blood macrophages after TB infection. TB infection reduced VPS11 levels in two human macrophages in vitro, but not in mouse macrophages. This might be because the seed sequence exists in the VPS11 3' untranslated region in humans, but is absent in mice and rats. miR-542-3p promoted M. tuberculosis survival in human macrophages, but VPS11 overexpression antagonized the promoting effect of miR-542-3p. Further, VPS11 was confirmed as a target of miR-542-3p. Overexpression of VPS11 or depletion of miR-542-3p promoted autophagy, which was suppressed upon TB infection. In summary, VPS11 overexpression antagonized the promoting effect of miR-542-3p on M. tuberculosis survival in macrophages by regulating autophagy.
自噬受损是分枝杆菌在巨噬细胞中存活的一个重要原因。VPS11 是自噬的重要调节因子；在结核分枝杆菌（TB）感染后，巨噬细胞中的 VPS11 表达下降。基因本体论数据显示，TB 感染后巨噬细胞中各种 miRNA（例如 miR-542-3p）上调；因此，这些 miRNA 可能降低 VPS11 的表达。在这项研究中，招募了 TB 患者和健康受试者，并测量了他们血液巨噬细胞中的 VPS11 和一些 miRNA 的水平。此外，培养了各种巨噬细胞并感染结核分枝杆菌。进行了荧光素酶报告、RNA 下拉和 RNA 免疫沉淀测定，以确定 miR-542-3p 对 VPS11 表达的调节作用。结果表明，TB 感染后血液巨噬细胞中的 VPS11 表达下调，而 miR-542-3p 表达上调。TB 感染在体外降低了两种人巨噬细胞中的 VPS11 水平，但在小鼠巨噬细胞中没有降低。这可能是因为种子序列存在于人 VPS11 的 3'非翻译区，但在小鼠和大鼠中不存在。miR-542-3p 促进人巨噬细胞中的结核分枝杆菌存活，但 VPS11 过表达拮抗了 miR-542-3p 的促进作用。此外，VPS11 被确认为 miR-542-3p 的靶标。VPS11 的过表达或 miR-542-3p 的耗竭促进了自噬，而 TB 感染抑制了自噬。总之，VPS11 过表达通过调节自噬拮抗了 miR-542-3p 对巨噬细胞中结核分枝杆菌存活的促进作用。
