Thymosin β4 Mitigates Acute Cerebral Infarction Via Inhibition of the TLR4/NF-κB Pathway and Suppression of Neuronal Pyroptosis.

Acute cerebral infarction (ACI), a severe neurological disorder, causes significant neuronal damage and brain injury, with cellular pyroptosis and abnormal activation of signaling pathways being key pathological contributors. This study aimed to investigate the protective effect and underlying mechanism of Thymosin β4 (Tβ4) against ACI. By establishing an oxygen-glucose deprivation/reoxygenation (OGD/R) model in HT22 mouse hippocampal neurons and a middle cerebral artery occlusion (MCAO) model in rat brains, the effects of Tβ4 on neuronal pyroptosis and the TLR4/NF-κB signaling pathway were systematically evaluated. Results demonstrated that Tβ4 significantly increased HT22 cell survival after OGD/R treatment, reduced lactate dehydrogenase (LDH) release, suppressed expression of pyroptosis-related proteins including NLRP3, ASC, cleaved caspase-1, and GSDMD-N, and decreased levels of inflammatory cytokines IL-18, IL-1β, and TNF-α. In the rat MCAO model, Tβ4 significantly reduced infarct volume, improved neurological function scores, decreased cerebral edema severity, and suppressed the expression of pyroptosis-related proteins and inflammatory cytokines in brain tissue. Mechanistically, Tβ4 inhibited the activation of the TLR4/NF-κB signaling pathway induced by OGD/R or cerebral ischemia both in vitro and in vivo, including suppression of p65 nuclear translocation as confirmed by immunofluorescence staining. Further gain- and loss-of-function experiments confirmed that Tβ4's anti-pyroptotic effects are mediated, at least partially, through inhibition of the TLR4/NF-κB pathway. In summary, Tβ4 exerts neuroprotective effects against ACI by suppressing the TLR4/NF-κB signaling pathway and mitigating neuronal pyroptosis, demonstrating potential clinical application value.