Background: Ischemic stroke is a leading cause of mortality and long-term disability globally. Current recanalization therapies, including mechanical thrombectomy and thrombolysis, aim to restore blood flow in acute ischemic stroke patients. However, many patients with successful recanalization still experience poor clinical outcomes. This phenomenon, where the restoration of blood flow does not translate into functional recovery, is known as futile recanalization. Methods: Using a murine middle cerebral occlusion (MCAO) model that mimics a large vessel occlusion with recanalization, a comprehensive microarray analysis of gene expression from blood samples collected during MCAO and after recanalization (N=44) was performed. Results: Il1r2, Cd55, Mmp8, Cd14, and Cd69 were key regulatory genes expressed early after MCAO and recanalization. A comparison with gene expression data from human stroke patients and rat MCAO model (GSE16561 and GSE21136) revealed Vcan as a differentially expressed gene conserved across species, marking it as a novel indicator of recanalization that was detected as early as 3 hours post-recanalization (4 hours post-MCAO) in mice and 24 hours after recanalization in rats (MCAO-thrombectomy) and humans (rtPA-thrombolysis). Leukocyte and neutrophil activation pathways were significantly enriched in the mouse data and human samples from GSE16561, with greater upregulation in female subjects. The analysis identified key miRNAs regulating gene expression in response to recanalization, and NFE4 and MTF1 as crucial transcription factors regulating these processes. Based on these data, a coregulatory network underlying neutrophil activity was constructed, highlighting its central role in early recanalization responses, especially in females. Conclusions: This study identified new genomic markers in blood associated with recanalization, and identified critical age- and sex-specific factors. By mapping a coregulatory network of interacting genes and neutrophil-related pathways, the data provides insights to inform future research and develop targeted therapies. Such therapies can improve recanalization efficacy or modulate leukocytes to reduce futile recanalization, ultimately enhancing clinical outcomes for ischemic stroke patients.

The authors have declared no competing interest.

Funding for this project was from CIHR Project Grant (180244, PI: Winship, Co-PI: Jickling)

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Data will be made available after publication via GEO accession GSE278554: https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE278554