Arg-Gly-Asp engineered mesenchymal stem cells as targeted nanotherapeutics against kidney fibrosis by modulating m6A

Background The recent surge in research on extracellular vesicles has generated considerable interest in their clinical applications. Extracellular vesicles derived from mesenchymal stem cells (MSC-EV) have emerged as a promising cell-free therapy for chronic kidney disease (CKD), offering an alternative to traditional Mesenchymal stem/stromal cells (MSCs) in extracellular vesicle-based nanotherapeutics. However, challenges such as in vivo off-target effects and limited bioavailability have impeded the wider adoption of MSC-EV in clinical settings. Methods Arginyl-glycyl-aspartic acid peptide-modified MSC-EV (RGD-MSC-EV) were developed using a donor cell-assisted membrane modification strategy. The targeting capability and therapeutic efficacy of RGD-MSC-EV were thoroughly evaluated both in vitro and in vivo. Additionally, the mechanisms of RNA N⁶-methyladenosine (m6A) methylation-mediated angiogenesis were extensively investigated to elucidate how RGD-MSC-EV mitigates renal fibrosis. Results RGD-MSC-EV demonstrated exceptional targeted delivery efficiency, exhibiting optimal biodistribution and retention within the target tissue. This breakthrough positions them as significantly enhanced anti-fibrotic therapeutics. Notably, RGD-MSC-EV sustains the viability of renal peritubular capillary (PTCs) endothelial cells by transporting microRNA-126-5p (miR-126-5p) and modulating alkB homolog 5 (ALKBH5)-mediated m6A modification of SIRT1(Sirtuin 1), a crucial regulator in angiogenesis. By revitalizing endothelial cells and promoting microcirculation, this approach restored oxygen metabolism homeostasis, ultimately delaying fibrogenesis associated with CKD. Conclusions RGD-MSC-EV offers a feasible and effective strategy to alleviate renal interstitial fibrosis by restoring m6A and mitigating the loss of renal PTCs. STATEMENT OF SIGNIFICANCE: Chronic kidney disease (CKD) often leads to renal fibrosis, which worsens disease progression. This study introduces a novel strategy using engineered extracellular vesicles (EVs) derived from mesenchymal stem cells (MSC-EV). By modifying these EVs with RGD peptides, we significantly enhance their targeting ability to hypoxic kidney tissues. The research reveals how these EVs deliver microRNA (miR-126-5p) to restore key molecular mechanisms, stabilizing SIRT1 expression through m6A RNA modifications. This approach promotes blood vessel health and delays fibrosis. Compared to current treatments, RGD-MSC-EV offers a safe, effective, and cell-free therapeutic alternative. These findings advance the understanding of EV-based therapies and their clinical potential, bridging basic research and real-world CKD treatment applications.