Therapeutic role of hucMSC-sEV-enriched miR-13896 in cisplatin-induced acute kidney injury through M2 macrophage polarization.

Human umbilical cord mesenchymal stem cell-derived small extracellular vesicles (hucMSC-sEV) have recently garnered attention as a potential therapeutic approach for kidney diseases with anti-inflammatory effects. Infiltrated macrophages play an important role in facilitating tissue regeneration. However, the intricate regulatory effects of hucMSC-sEV on macrophages during cisplatin-induced acute kidney injury (AKI) remain unknown. In this study, we uncovered that hucMSC-sEV exhibited potent anti-inflammation and effectively inhibited the polarization of M1 phenotype macrophages. Mechanically, miRNA sequencing analysis and qRT-PCR indicated that a novel miRNA, named miR-13896, was enriched in hucMSC-sEV. When transfected with miR-13896 mimic, macrophages displayed M2 phenotype with elevated levels of Arg1 and IL-10, while miR-13896 inhibitor promoted M1 phenotype. Furthermore, we firstly established that miR-13896 repressed Tradd expression by targeting its 3' untranslated region and subsequently inhibited NF-κB signaling pathway in macrophages. Additionally, to improve therapeutic effects, hucMSC-sEV were engineered with elevated levels of miR-13896 through electroporation, which resulted in promoting M2 phenotype macrophages, inhibiting inflammatory factors, and enhancing kidney repair. Conclusively, our findings provide novel insights into the mechanisms underlying the effects of hucMSC-sEV on macrophages and AKI, while also highlighting electroporation as a promising strategy for treating cisplatin-induced AKI.