Annexin A5 confers neuroprotection in ischemic stroke: insights from in vitro and in vivo models

Ischemic stroke remains a leading cause of neurological disability worldwide. Effective therapeutic interventions for stroke treatment are still critically needed. Annexin A5, a calcium-dependent phospholipid-binding protein, has been reported to possess a wide range of biological functions, including anti-inflammation, anticoagulation and antithrombotic, and apoptosis regulation. It also has protective effects on the ischemic stroke. Previous studies have demonstrated that Annexin A5 has neuroprotective effects during ischemic stroke. However, there is still a lack of systematic research on the exact mechanism. Our study aims to clarify the related signaling pathways of Annexin A5 after ischemic stroke. In the present study, we validated that Annexin A5 administration significantly enhanced neuronal survival and attenuated apoptotic processes in both in vitro and in vivo models. As expected, Annexin A5 treatment led to a reduction in infarct volume and improved neurological function scores in tMCAO mouse models. Notably, RNA-seq identified 1430 differentially expressed genes (DEGs) between OGD/R and Annexin A5-treated groups. Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed involvement in multiple signaling cascades, such as apoptosis, TGF-β pathway, NOD-like receptor pathway, phagosome, PI3K-Akt pathway, necroptosis, NF-kB pathway. These findings were subsequently validated through qRT-PCR analysis, showing high concordance with RNA-seq results. Our integrated findings propose the multi-target mechanism positions Annexin A5 as a potential therapeutic candidate for ischemic stroke management.