Institute of Reproductive and Developmental Biology, Department of Metabolism, Digestion, and Reproduction, Imperial College London, London, UK.
Omiics ApS, Aarhus, Denmark.
J Extracell Vesicles. 2022 Dec;11(12):e12293. doi: 10.1002/jev2.12293.
Macrophages are important antigen presenting cells which can release extracellular vesicles (EVs) carrying functional cargo including non-coding RNAs. Macrophages can be broadly classified into M1 'classical' and M2 'alternatively-activated' macrophages. M1 macrophages have been linked with inflammation-associated pathologies, whereas a switch towards an M2 phenotype indicates resolution of inflammation and tissue regeneration. Here, we provide the first comprehensive analysis of the small RNA cargo of EVs from human M1 and M2 primary macrophages. Using small RNA sequencing, we identified several types of small non-coding RNAs in M1 and M2 macrophage EVs including miRNAs, isomiRs, tRNA fragments, piRNA, snRNA, snoRNA and Y-RNA fragments. Distinct differences were observed between M1 and M2 EVs, with higher relative abundance of miRNAs, and lower abundance of tRNA fragments in M1 compared to M2 EVs. MicroRNA-target enrichment analysis identified several gene targets involved in gene expression and inflammatory signalling pathways. EVs were also enriched in tRNA fragments, primarily originating from the 5' end or the internal region of the full length tRNAs, many of which were differentially abundant in M1 and M2 EVs. Similarly, several other small non-coding RNAs, namely snRNAs, snoRNAs and Y-RNA fragments, were differentially enriched in M1 and M2 EVs; we discuss their putative roles in macrophage EVs. In conclusion, we show that M1 and M2 macrophages release EVs with distinct RNA cargo, which has the potential to contribute to the unique effect of these cell subsets on their microenvironment.
巨噬细胞是重要的抗原呈递细胞，可释放携带功能性 cargo 的细胞外囊泡（EVs），包括非编码 RNA。巨噬细胞可广泛分为 M1“经典”和 M2“替代激活”巨噬细胞。M1 巨噬细胞与炎症相关病理有关，而向 M2 表型的转变表明炎症的解决和组织再生。在这里，我们首次对来自人源 M1 和 M2 原代巨噬细胞的 EVs 的小 RNA 货物进行了全面分析。使用小 RNA 测序，我们在 M1 和 M2 巨噬细胞 EVs 中鉴定了几种类型的小非编码 RNA，包括 miRNA、isomiR、tRNA 片段、piRNA、snRNA、snoRNA 和 Y-RNA 片段。M1 和 M2 EVs 之间观察到明显的差异，M1 EVs 中的 miRNA 相对丰度较高，而 tRNA 片段的丰度较低。miRNA 靶基因富集分析确定了几个参与基因表达和炎症信号通路的基因靶标。EVs 还富含 tRNA 片段，主要来源于全长 tRNA 的 5' 端或内部区域，其中许多在 M1 和 M2 EVs 中丰度不同。类似地，几种其他小非编码 RNA，即 snRNA、snoRNA 和 Y-RNA 片段，在 M1 和 M2 EVs 中差异富集；我们讨论了它们在巨噬细胞 EVs 中的潜在作用。总之，我们表明 M1 和 M2 巨噬细胞释放具有不同 RNA 货物的 EVs，这些 RNA 货物有可能对这些细胞亚群对其微环境的独特影响做出贡献。
