H2O2-induced astrocytic collagen triggers neuronal death in ischemic stroke [ATAC-seq]

Ischemic stroke is a brain injury caused by the occlusion of blood vessels, leading to reduced blood flow, excessive oxidative stress, and the cascade of events, including the formation of the glial barrier, fibrotic scar, neuronal death, and motor impairment. Despite extensive research into stroke etiology, the specific initiation trigger for neuronal death is mainly unknown, severely limiting the development of effective treatments. Here, we demonstrate that excessive H2O2 generation is the initiating factor of ischemic stroke in the photo-thrombosis (PT) mouse and non-human primate (NHP) models, with H2O2-induced astrocytic type I collagen (COL1) playing a crucial role in the cascade of stroke pathology. Treatment with KDS12025, an H2O2-decomposing peroxidase enhancer, significantly alleviates these effects by reducing H2O2-induced COL1 in extremely low doses in mouse and NHP stroke models. In cultured astrocytes, H2O2 stimulates the production of astrocytic COL1 through post-transcriptional up-regulation of Col1 mRNA by decreasing microRNA29, leading to the death of neighboring neurons. Using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI), we observe profound alterations in N-glycan profiles, particularly fucosylated N-glycans, which reverted to normal levels in both the KDS12025 treatment and astrocytic Col1 gene-silencing groups. The gene-silencing of astrocytic Col1 or Fut8, a key enzyme responsible for core fucosylation necessary for COL1 secretion, prevents neuronal death and motor impairment. Our findings reveal that H2O2-induced astrocytic COL1 production is critical to ischemic stroke. These findings propose that targeting H2O2, astrocytic COL1, and FUT8 could be effective therapeutic strategies for ischemic stroke, offering new avenues for treatment.