Department of Pathology, Third Xiangya Hospital, Central South University, Changsha, People's Republic of China.
Gastrointestinal Surgery, Third Xiangya Hospital, Central South University, Changsha, People's Republic of China.
Immunology. 2022 Dec;167(4):606-621. doi: 10.1111/imm.13558. Epub 2022 Sep 7.
Macrophages, associated with their heterogenous and dynamic polarization status, actively shape the development of renal fibrosis (RF). In this study, we revealed the significance of a signalling axis, circular RNA ACTR2 (circACTR2)/miR-200c/Yes-associated protein (YAP), in regulating macrophage polarization and the development of RF. A unilateral urethral obstruction (UUO)-induced RF model was established in vivo. In vitro, interferon-γ (IFNγ) and interleukin (IL)-4 were applied to induce M1 and M2 polarization, respectively. The abundance of M1 and M2 macrophages were examined by immunofluorescence (IF) or flow cytrometry on markers specific for each subtype. Expressions of circACTR2, miR-200c and YAP were measured by quantitative real-time-polymerase chain reaction and/or Western blotting. Interactions between circACTR2, miR-200c and YAP were examined by combining luciferase assay, RNA immunoprecipitation and IF. Impact of targeting circACTR2 on RF and macrophage polarization was also examined in vivo. UUO-induced RF was associated with increased M1 and M2 macrophages, up-regulations of circACTR2 and YAP and the down-regulation of miR-200c in the obstructed kidney. circACTR2 was essential for IL-4-induced M2 polarization, but not IFNγ-induced M1 polarization. This activity of circACTR2 was mediated by sponging miR-200c and activating the downstream YAP signalling. In vivo, knocking down circACTR2 boosted miR-200c expression, reduced YAP level, lowered M2 macrophages in obstructed kidney and ameliorated UUO-induced RF. circACTR2, by targeting and sponging miR-200c, activates YAP signalling, stimulates M2 macrophage polarization and promotes the development of RF. Therefore, targeting circACTR2 may benefit the treatment of RF.
巨噬细胞与其异质和动态极化状态相关，积极塑造肾纤维化 (RF) 的发展。在这项研究中，我们揭示了信号轴 circACTR2/miR-200c/Yes 相关蛋白 (YAP) 在调节巨噬细胞极化和 RF 发展中的重要性。体内建立单侧输尿管梗阻 (UUO) 诱导的 RF 模型。体外，应用干扰素-γ (IFNγ) 和白细胞介素 (IL)-4 分别诱导 M1 和 M2 极化。通过免疫荧光 (IF) 或流式细胞术检测标记物特异性检测 M1 和 M2 巨噬细胞的丰度每种亚型。通过定量实时聚合酶链反应和/或 Western blot 测量 circACTR2、miR-200c 和 YAP 的表达。通过结合荧光素酶测定、RNA 免疫沉淀和 IF 检测 circACTR2、miR-200c 和 YAP 之间的相互作用。还在体内检查了靶向 circACTR2 对 RF 和巨噬细胞极化的影响。UUO 诱导的 RF 与阻塞肾脏中 M1 和 M2 巨噬细胞增加、circACTR2 和 YAP 上调以及 miR-200c 下调有关。circACTR2 对于 IL-4 诱导的 M2 极化是必需的，但不是 IFNγ 诱导的 M1 极化。circACTR2 的这种活性是通过海绵 miR-200c 和激活下游 YAP 信号转导来介导的。在体内，敲低 circACTR2 可增加 miR-200c 的表达，降低 YAP 水平，降低阻塞肾脏中的 M2 巨噬细胞，并改善 UUO 诱导的 RF。circACTR2 通过靶向和海绵 miR-200c 激活 YAP 信号通路，刺激 M2 巨噬细胞极化并促进 RF 的发展。因此，靶向 circACTR2 可能有益于 RF 的治疗。
