Engineering RVG-modified exosomes for targeting TGF-β1 signaling in stroke recovery

OBJECTIVE: To investigate the role of TGF-β1 signaling in astrocyte-neuron interactions after ischemic stroke and to develop a brain-targeted engineered exosome system, EXO-RVG-SD208, for promoting neural repair. METHODS: Public datasets and transcriptomic analyses were used to characterize the dynamic changes of TGF-β1 after stroke, and key targets were identified through GO, KEGG, and WGCNA analyses. A brain-targeted engineered exosome, EXO-RVG-SD208, was constructed and characterized for its physicochemical properties. Its inhibitory effect on the TGF-β1/Smad2/3 pathway in astrocytes and its neuroregenerative potential were evaluated in oxygen-glucose deprivation/reoxygenation (OGD/R) and neuron-astrocyte co-culture models. Therapeutic efficacy was further assessed in a middle cerebral artery occlusion/reperfusion (MCAO/R) mouse model. Integrated multi-omics analyses were performed to explore the downstream mechanisms involved in neural repair. RESULTS: TGF-β1 was markedly upregulated after stroke and was predominantly derived from astrocytes, where it was closely associated with neuroinflammation and impaired neuroplasticity. EXO-RVG-SD208 effectively inhibited activation of the TGF-β1/Smad2/3 pathway, promoted astrocyte phenotypic remodeling, enhanced neuronal synaptic activity, and improved functional recovery in MCAO/R mice. Multi-omics analyses further indicated that the therapeutic effects were associated with the regulation of mTOR, BDNF, and MAPK-related pathways. CONCLUSION: EXO-RVG-SD208 effectively delivered TGF-β1 inhibitor to the brain, suppressed astrocytic TGF-β1/Smad2/3 activation, facilitated astrocyte-neuron remodeling, synaptic reconstruction, and neural functional recovery, presenting a promising nanodelivery strategy for stroke rehabilitation.