[Nano-vesicles derived from M1 macrophages affect the development of mouse endometriosis by polarizing M2 macrophages...

Objective To explore whether nano-vesicles derived from M1 macrophages (M1-NVs) can reprogram M2 macrophages into M1 phenotype and further affect the development of endometriosis (EMS). Methods Extracellular vesicles (EVs) were isolated from macrophage culture supernatant by differential centrifugation. Immunofluorescence cytochemistry was used to detect the expression of vimentin, CD31 and F4/80 to identify endometrial stromal cells (EMS-ESCs), HUVECs and polarized peritoneal macrophages of EMS patients. M1-NVs were prepared by filtering cell suspension through (5, 1, 0.4, 0.22)μm polycarbonate membrane filters after syringe aspiration at 0-4 DegreesCelsius. Flow cytometry was used to analyze the polarization of RAW264.7 mouse peritoneal macrophages in vitro, and reverse transcription PCR (RT-qPCR) was employed to detect mRNA expression of VEGF, CD86, interleukin-6 (IL-6), IL-1β, tumor necrosis factor α (TNF-α), arginase 1 (Arg1), CD163, CD206, and IL-10. PKH67-labeled M1-NVs were co-cultured with EMS-ESCs, HUVECs and macrophages. And tubule formation experiments were conducted to assess the impact of M1-NVs on the tubule formation of HUVECs. Transwell^TM invasion and migration assays were employed to evaluate changes in the migration and invasion abilities of EMS-ESCs. Results By monitoring the contents of NVs, it was found that NVs contained much more protein and other bioactive particles than the same amount of EVs; immunofluorescence staining results showed that PKH67 labeled M1-NVs were internalized by EMS-ESCs, HUVECs and macrophages when co-cultured. The results of flow cytometry and RT-qPCR multi-target analysis showed that after treatment with different concentrations of M1-NVs or M0-NVs, 20 μg/mL of M1-NVs could effectively reprogram M2 macrophages into M1 macrophages compared with M0-NVs. Transewell^TM results showed that compared with the blank group and M0-NVs group, the number of EMS-ESCs migrating from the upper chamber to the lower chamber after M1-NV treatment was significantly reduced, while the number of EMS-ESCs treated with M2NVs increased significantly. The invasion situation was similar to the migration situation, indicating that M1-NVs directly or indirectly inhibited invasion, migration and tubule formation of EMS-ESCs in vitro. Conclusion M1-NVs reprogrammes M2 macrophages into M1 macrophages by internalization of primary cells and macrophages, thereby inhibiting invasion, migration and angiogenesis of EMS-ESCs, and further hindering the occurrence and development of EMS.