Houttuynia cordata Thunb-derived extracellular vesicle-like particles alleviate ischemic brain injury by miR159a targeting ACSL4 to suppress ferroptosis.

Introduction: Neuroprotective agents for acute ischemic stroke often fall short in efficacy due to the blood-brain barrier challenges, lack of target specificity, and limited effectiveness. Recently, plant-derived extracellular vesicle-like particles (EVLP) have shown promise in their multifaceted functions.

Objectives: The neuroprotective advantages that EVLP produced from Houttuynia cordata Thunb against cerebral ischemia/reperfusion injury are investigated.

Methods: The extraction of HT-EVLP was performed using gradient centrifugation and ultracentrifugation, followed by identification of its particle size, morphology, and exosomal marker proteins. Using behavioral tests and a rat model of middle cerebral artery occlusion (MCAO), the neuroprotective attributes of HT-EVLP were assessed. To evaluate the effect of HT-EVLP on ferroptosis and cell survival, the oxygen-glucose deprivation/reoxygenation (OGD/R) induced HT22 cell model was used. Utilizing bioinformatics analysis and small RNA sequencing, the miRNA composition and downstream target genes of HT-EVLP were predicted. The dual-luciferase reporter gene assay was used to confirm that miR159a bound to long-chain acyl-coenzyme A synthase 4 (ACSL4). The impact of miR159a transfection on OGD/R-induced ferroptosis in HT22 cell was also observed.

Results: Using a MCAO model, we found that HT-EVLP preserved blood brain barrier integrity, naturally penetrated the infarct core area, reduced cerebral infarct volume, mitigated neuronal apoptosis and ferroptosis, and facilitated recovery of neuronal function. In vitro studies further revealed that HT-EVLP enhanced cell survival and suppressed ACSL4-mediated ferroptosis in OGD/R-treated HT22 cells. Small RNA sequencing indicated that HT-EVLP are rich in miRNAs, with miR159a, among the top 10, potentially regulating ferroptosis-related pathways and directly binding to the 3'UTR of ACSL4. Overexpression of miR159a reduced Erastin-induced ACSL4 expression and alleviated mitochondrial damage in HT22 cells without causing toxicity.

Conclusions: This study highlights the potential of HT-EVLP as carriers of endogenous miR159a, offering a promising strategy for ischemic brain injury therapy.