Abstract

Background Diabetic retinopathy (DR) is a leading cause of blindness. While anti-vascular endothelial growth factor (VEGF) therapy is effective, its utility is limited by variable patient response and the need for frequent injections. Therefore, identifying new therapeutic targets for DR is imperative. Emerging evidence indicates that astrocytes contribute to endothelial dysfunction in DR, suggesting that targeting astrocyte-endothelial cell crosstalk represents a promising therapeutic strategy. Purpose To evaluate the therapeutic potential of Salvianolic acid A (Sal A) for DR, elucidate the molecular mechanisms by which it modulates astrocyte-endothelial cell interactions, and develop a liposome-based nanodelivery system to enhance its efficacy. Study Design The protective effects and mechanisms of Sal A were systematically investigated using a streptozotocin (STZ)-induced diabetic mouse model, complemented by a suite of in vitro and molecular approaches including co-culture models, transcriptomic analysis, and target validation assays. Methods Retinal vascular structure and barrier function were assessed in vivo via immunofluorescence staining and Evans Blue leakage assays. Endothelial cell behaviors were examined in vitro using wound healing, Transwell migration, tube formation, and spheroid sprouting assays. Transcriptomic profiling was performed by RNA sequencing (RNA-seq). The direct target of Sal A was identified and validated using MS-based drug-affinity responsive target stability (DARTS) screening, cellular thermal shift assay (CETSA), and microscale thermophoresis (MST). Expression of key signaling molecules was measured by western blotting, enzyme-linked immunosorbent assay (ELISA), and quantitative real-time PCR (qRT-PCR). Liposome@Sal A was prepared and characterized for its physicochemical properties (dynamic light scattering, transmission electron microscopy), stability, and therapeutic efficacy in vitro and in vivo. Results Sal A treatment ameliora