SIRT1 activation by Ligustrazine ameliorates migraine via the paracrine interaction of microglia and neurons.

BACKGROUND

Neuroinflammation with associated oxidative stress aggravates the pathogenesis and progression of migraine. Ligustrazine (LGZ) is a key component from traditional edible-medicinal herb Ligusticum chuanxiong Hort., and has the effects of anti-platelet aggregation, expanding small arteries, improving microcirculation and promoting blood circulation and removing blood stasis in clinic.

HYPOTHESIS/PURPOSE: This study aims to investigate the pharmacological effect and mechanism of LGZ in migraine.

STUDY DESIGN/METHODS: A mouse model of migraine was induced by nitroglycerin (NTG), and LPS/IFN-γ stimulated microglial cell model was conducted to investigate neuroinflammation, the paracrine interactions between microglia and neurons were determined by the co-culture system, and the effect of LGZ on stability of SIRT1 protein was measured by cellular thermal shift assay (CETSA). Whilst, the SIRT1 inhibitor EX527 was used alone or co-treatment with LGZ in vitro or in vivo.

RESULTS

LGZ significantly attenuated migraine-like behaviors in NTG-induced mice, and ameliorated neuroinflammation and related oxidative damage in brain tissue, but co-treatment with SIRT1 inhibitor EX527 abolished the protective effects of LGZ. Mechanistically, LGZ mitigated neuroinflammation by upregulating SIRT1 expression and subsequently inhibiting the activation of NF-κB pathway in microglia. CETSA indicated that LGZ significantly maintained the stability of SIRT1 protein in microglia. While, in the co-culture system, culture medium from LPS/IFN-γ-treated microglia exacerbated neuronal damage and oxidative stress, which was suppressed by treating LPS/IFN-γ-induced microglia with LGZ, this effect might be related to the activation of Nrf2 signals in neurons. Notably, SIRT1 inhibitor EX527 abrogated the effects of LGZ both in vitro and in vivo.

CONCLUSION

Consequently, SIRT1 might be an important pharmacological target of LGZ, which attenuates migraine associated neuroinflammation and oxidative stress by interfering the crosstalk between microglia and neurons, thereby relieving migraine.