Brain-targeted extracellular vesicles for anti-cuproptosis therapy in subarachnoid haemorrhage.

Background: Subarachnoid haemorrhage (SAH) is primarily caused by ruptured aneurysms with high mortality worldwide. Cuproptosis is a copper-induced cell death that regulates lipoylated tricarboxylic acid cycle proteins. The link between cuproptosis and SAH is unclear. To inhibit cuproptosis for SAH treatment, we designed brain-targeted delivery of siRNA to inhibit cuproptosis.

Methods: Transcriptome data of SAH related to cuprotosis were extracted from the Gene Expression Omnibus and defined using quantitative reverse transcription-PCR. We injected RVG-RBCEVs/siRNA (rabies virus glycoprotein-red blood cell extracellular vesicles/siRNA) peripherally to deliver LIAS (lipoyl synthase) siRNA to the brain tissues of SAH mice. The influences of RVG-RBCEVs/siRNA on copper levels, enrichment of cuproptosis functional proteins, glutathione and malondialdehyde content, mitochondrial respiration and membrane potential, transmission electron microscope, a neurological score, brain water content, blood-brain barrier injury and Fluoro-Jade C staining were examined.

Results: Our findings revealed that three cuproptosis-related genes (CRGs) were differentially expressed. The RVG peptides were conjugated to the red blood cell extracellular vesicle surface by bio-orthogonal click chemistry reactions, and then the loading of siRNA was conducted. RVG-RBCEVs/siRNA was selectively taken up by neurons but not glial cells; it facilitated the downregulation of LIAS of CRGs, reduced the accumulation of reactive oxygen species, inhibited neuronal cuprotosis and exerted neuroprotective effects in vivo.

Conclusions: These findings suggest that cuprotosis is critical for inducing neural injury after SAH. Neuron-targeted RVG-RBCEVs/siRNA treatment attenuated oxidative stress by inhibiting cuproptosis via suppressed LIAS expression. This innovative approach alleviates neurobehavioural impairments and represents a neuroprotective strategy following SAH.