[Gastrodin alleviates microglia-mediated inflammatory responses in neonatal mice with hypoxic-ischemic brain damage by regulating CCR5/AKT signaling].

OBJECTIVE

To investigate the mechanism behind the protective effects of gastrodin against microglia-mediated inflammatory responses following hypoxic-ischemic brain damage (HIBD) in neonatal mice.

METHODS

Thirty-six 10-day-old C57BL/6J mice were randomized into sham-operated group, HIBD (induced by ligation of the left common carotid artery followed by hypoxia for 40 min) group, and HIBD with gastrodin treatment groups (n=12). In gastrodin treatment group, 100 mg/kg gastrodin was injected intraperitoneally 1 h before and at 2 and 12 h after hypoxia. After the treatments, the expressions of CCR5, AKT, p-AKT, and TNF-α and the co-expression of IBA1 and CCR5 in the corpus callosum of the mice were detected with Western blotting and immunofluorescence double staining. In a BV2 microglial cell model of oxygen-glucose deprivation (OGD), the effects of pretreatment with gastrodin and Maraviroc (an CCR5 antagonist) on protein expressions of CCR5, AKT, p-AKT, TNF-α and IL-1β were evaluated using Western blotting and immunofluorescence double staining.

RESULTS

The neonatal mice with HIBD showed significantly increased expressions of CCR5 and TNF-α with lowered p-AKT expression in the brain tissues, and GAS treatment obviously reversed these changes. HIBD also significantly increased the co-expression of IBA1 and CCR5 in the corpus callosum of the mice, which was obviously lowered by gastrodin treatment. In BV2 cells, OGD significantly increased the expressions of CCR5, TNF-α, and IL-1β and decreased the expression of p-AKT, and these changes were inhibited by treatment with gastrodin, Maraviroc or their combination; the inhibitory effect of the combined treatment did not differ significantly from that of gastrodin or Maraviroc alone.

CONCLUSION

Gastrodin can produce neuroprotective effects in neonatal mice with HIBD by inhibiting inflammatory cytokine production and activate AKT phosphorylation via inhibiting CCR5.