Therapeutic Potential of hucMSC‐EVs in Diabetic Kidney Disease via Regulating the miR‐146b‐5p/Merlin/YAP Axis

Diabetic kidney disease (DKD) is characterized by a continuous decline in renal function and progressive fibrosis, making it a leading cause of end-stage kidney disease with limited therapeutic options. Recently, extracellular vesicles derived from mesenchymal stem cells (MSC-EVs) have shown great potential in tissue regeneration and repair, offering a new avenue for the treatment of DKD. The purpose of this study is to explore the function and mechanism of action of EVs derived from human umbilical cord MSCs (hucMSC-EVs) in the development of DKD. Our findings show that under high-glucose (HG) conditions, miR-146b-5p is highly expressed in glomerular mesangial cells, downregulating the target protein Merlin, which promotes the activation of the YAP signaling pathway and induces mesangial cell fibrotic-like changes, leading to a significant deposition of collagen and interstitial fibrosis in the kidney. In vivo and in vitro experimental findings reveal that hucMSC-EVs can significantly inhibit miR-146b-5p, upregulate Merlin expression, prevent the nuclear translocation of YAP, improve renal function, and reduce collagen deposition, demonstrating a significant antifibrotic effect. The findings of this study emphasize the central role of the miR-146b-5p/Merlin/YAP axis in hucMSC-EVs-mediated inhibition of renal fibrosis and highlight the potential of MSC-EVs as a targeted nanotherapeutic strategy for DKD.