摘要Objective Patients with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection frequently develop central nervous system damage,yet the mechanisms driving this pathology remain unclear.This study investigated the primary pathways and key factors underlying brain tissue damage induced by the SARS-CoV-2 beta variant(lineage B.1.351).Methods K18-hACE2 and C57BL/6 mice were intranasally infected with the SARS-CoV-2 beta variant.Viral replication,pathological phenotypes,and brain transcriptomes were analyzed.Gene Ontology(GO)analysis was performed to identify altered pathways.Expression changes of host genes were verified using reverse transcription-quantitative polymerase chain reaction and Western blot.Results Pathological alterations were observed in the lungs of both mouse strains.However,only K18-hACE2 mice exhibited elevated viral RNA loads and infectious titers in the brain at 3 days post-infection,accompanied by neuropathological injury and weight loss.GO analysis of infected K18-hACE2 brain tissue revealed significant dysregulation of genes associated with innate immunity and antiviral defense responses,including type I interferons,pro-inflammatory cytokines,Toll-like receptor signaling components,and interferon-stimulated genes.Neuroinflammation was evident,alongside activation of apoptotic and pyroptotic pathways.Furthermore,altered neural cell marker expression suggested viral-induced neuroglial activation,resulting in caspase 4 and lipocalin 2 release and disruption of neuronal molecular networks.Conclusion These findings elucidate mechanisms of neuropathogenicity associated with the SARS-CoV-2 beta variant and highlight therapeutic targets to mitigate COVID-19-related neurological dysfunction.