Li Shuling, Zhu Xiaoyu, Wang Xuhong, Jia Jintong, Chen Mengsi, Wang Qian, Wang Lingling, Lu Peipei, Luo Bin, Yang Min, Pan Junyao, Liu Yezi, Li Zhiwei
Clinical Laboratory Center, People's Hospital of Xinjiang Uygur Autonomous Region, Urumqi, 830001, Xinjiang, China.
Clinical Laboratory, Karamay Central Hospital, Karamay, 834000, Xinjang, China.
Eur J Med Res. 2025 Jul 9;30(1):607. doi: 10.1186/s40001-025-02867-y.
Numerous studies have demonstrated that exosomal microRNAs (miRNAs) are closely associated with the pathological mechanisms underlying various infectious diseases, including brucellosis. Concurrently, macrophage polarization has been identified as a critical factor in the pathogenesis of brucellosis. However, the question of whether exosomal microRNAs can regulate macrophage polarization and thereby contribute to the pathogenesis of brucellosis remains unresolved. Our study investigates the role of exosomal miR-let-7e-5p and the Rictor/AKT1 signaling pathway in macrophage polarization, elucidating a novel mechanism and potential therapeutic strategies for brucellosis.
Serum exosomes from patients with brucellosis and healthy controls were isolated and characterized. High-throughput sequencing was conducted to identify differentially expressed microRNAs. THP-1 cells were utilized for in vitro experiments. Macrophage polarization was confirmed using flow cytometry and cytometric bead array (CBA). The expression levels of miR-let-7e-5p and Rictor were quantified using quantitative reverse transcription polymerase chain reaction (qRT-PCR). Western blotting was employed to assess the protein abundance of Rictor, AKT1, and p-AKT1 (Ser473). Additionally, the relationship between miR-let-7e-5p and Rictor was explored through bioinformatics analysis, dual-luciferase reporter gene assays, and rescue experiments.
Serum-derived exosomes from brucellosis patients induced the M2 macrophage polarization and elevated the expression of the M2 marker IL-10 in vitro. Notably, the expression of miR-let-7e-5p was found to be downregulated in the exosomes from brucellosis patients. Overexpression of miR-let-7e-5p promoted M1 macrophage polarization while inhibiting M2 polarization. Rictor was identified as a target gene of miR-let-7e-5p and is a key molecule in macrophage polarization. Furthermore, overexpression of Rictor enhanced M2 polarization and activated the AKT1 signaling pathway. The rescue experiment demonstrated that the overexpression of Rictor counteracted the effects of miR-let-7e-5p overexpression, thereby further confirming the binding relationship between these two molecules.
The downregulation of exosomal miR-let-7e-5p promotes macrophage polarization toward the M2 phenotype through the Rictor/AKT1 signaling pathway. These findings provide insights into the pathogenesis of brucellosis and may suggest novel therapeutic strategies.
大量研究表明，外泌体微小RNA（miRNA）与包括布鲁氏菌病在内的各种传染病的病理机制密切相关。同时，巨噬细胞极化已被确定为布鲁氏菌病发病机制中的关键因素。然而，外泌体微小RNA是否能调节巨噬细胞极化从而促进布鲁氏菌病的发病机制这一问题仍未得到解决。我们的研究调查了外泌体miR-let-7e-5p和Rictor/AKT1信号通路在巨噬细胞极化中的作用，阐明了布鲁氏菌病的一种新机制和潜在治疗策略。
分离并鉴定布鲁氏菌病患者和健康对照者的血清外泌体。进行高通量测序以鉴定差异表达的微小RNA。利用THP-1细胞进行体外实验。使用流式细胞术和细胞因子珠阵列（CBA）确认巨噬细胞极化。使用定量逆转录聚合酶链反应（qRT-PCR）定量miR-let-7e-5p和Rictor的表达水平。采用蛋白质印迹法评估Rictor、AKT1和p-AKT1（Ser473）的蛋白质丰度。此外，通过生物信息学分析、双荧光素酶报告基因测定和拯救实验探索miR-let-7e-5p与Rictor之间的关系。
布鲁氏菌病患者血清来源的外泌体在体外诱导M2巨噬细胞极化并提高M2标志物IL-10的表达。值得注意的是，发现布鲁氏菌病患者外泌体中miR-let-7e-5p的表达下调。miR-let-7e-5p的过表达促进M1巨噬细胞极化，同时抑制M2极化。Rictor被鉴定为miR-let-7e-5p的靶基因，是巨噬细胞极化中的关键分子。此外，Rictor的过表达增强了M2极化并激活了AKT1信号通路。拯救实验表明，Rictor的过表达抵消了miR-let-7e-5p过表达的作用，从而进一步证实了这两种分子之间的结合关系。
外泌体miR-let-7e-5p的下调通过Rictor/AKT1信号通路促进巨噬细胞向M2表型极化。这些发现为布鲁氏菌病的发病机制提供了见解，并可能提示新的治疗策略。
