Nanoparticle-delivered miR-486-5p inhibits H2O2-induced injury in cultured endothelial and kidney tubular epithelial cells

Abstract

Acute kidney injury (AKI) is a serious condition characterized by a sudden decrease in kidney function, often leading to chronic kidney disease. Current treatment options are limited, necessitating novel therapeutic strategies. We previously showed that microRNA-486-5p (miR-486-5p) protects against AKI by regulating cell death (apoptosis) both in vitro and in vivo. However, efficient and selective delivery remains a challenge. In this study, we designed and developed nanoparticles (NPs) to encapsulate and deliver miR-486-5p to cultured endothelial and kidney tubular epithelial cells. NPs were characterized and optimized for size, polydispersity index, surface charge, and encapsulation efficiency. The stability of NPs in long-term storage and in biological solutions was confirmed. Results indicated effective cellular uptake of NPs, cargo microRNA delivery to the intracellular environment, and the absence of cytotoxicity upon NP treatment. Functional assessments showed that miR-486-5p-encapsulating lipid-polymeric hybrid NPs (HNPs) suppressed the expression of Forkhead Box Protein O1 (FOXO1), a validated target of miR-486-5p, in all cell lines investigated, suggesting effective miR-486-5p protection and transport. Both endothelial and tubular epithelial cells were significantly protected against induced apoptosis when pretreated with miR-486-5p-encapsulating HNPs. However, selective siRNA-mediated knockdown of FOXO1 did not result in injury protection, suggesting involvement of other miR-486-5p targets. Furthermore, cell injury-induced expression of inflammatory cytokines was inhibited by HNP-delivered miR-486-5p in both cell lines. These findings demonstrate the protective and anti-inflammatory effects of miR-486-5p-HNP systems in injured endothelial and tubular epithelial cells, highlighting their capacity as a potential nano-therapy for AKI and paving the way for in vivo studies and clinical applications.