Metab Brain Dis. 2026 May 20;41(1):110. doi: 10.1007/s11011-026-01833-9.
ABSTRACT
BACKGROUND: Mild hypothermia (MH) has been reported to ameliorate cerebral damage and neurofunctional deficits in ischemic stroke, but its molecular mechanisms remain unclear. This study focuses on exploring the neuroprotective regulatory mechanisms mediated by MH in ischemic stroke.
METHODS: A middle cerebral artery occlusion (MCAO) model in vivo was established. MCAO model and LPS-induced microglial cell model were treated with EphB4 kinase inhibitor NVP-BHG712. Brain tissue damage was assessed through 2,3,5-triphenyl tetrazolium chloride (TTC) staining, infarct volume measurement, and brain edema evaluation. Neurological and behavioral functions were evaluated via the rotarod test, grip test, Elevated body swing test (EBST) and neurological deficit scores. Immunofluorescence staining was employed to quantify M1 microglial polarization in brain tissues. The expression of M1 microglial markers and pro-inflammatory cytokines were analyzed by qRT-PCR. Furthermore, qRT-PCR and Western blotting were utilized to quantify key components of the EFNB2/EphB4 signaling axis.
RESULTS: MH significantly attenuated cerebral infarct volume, ameliorated neuromotor deficits, and alleviated cerebral edema in MCAO mice model. Histopathological analyses revealed that MH suppressed neuroinflammation by reducing M1-polarized microglial infiltration and downregulating M1-specific markers (CD16, IBA-1, CD32, CD86). Concurrently, MH inhibited the release of pro-inflammatory cytokines IL-1β and IL-18. In vitro, MH attenuated (LPS)-induced microglial M1 polarization and inflammation. Moreover, hypothermia upregulated EFNB2/EphB4 signaling pathways in both models. Importantly, pharmacological inhibition of EFNB2 abrogated the anti-inflammatory function and neuroprotective effects.
CONCLUSION: MH exerts neuroprotective effects by modulating the EFNB2/EphB4 signaling pathway, attenuating post-ischemic neuroinflammation and ameliorating secondary brain injury in ischemic stroke.
PMID:42159828 | DOI:10.1007/s11011-026-01833-9