Relationship between cGAS-STING signaling pathway and ferritinophagy in early stage of cerebral ischemia-reperfusion in mice / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the relationship between the second messenger cyclic GMP-AMP (cGAS)-cyclic GMP-AMP receptor stimulator of interferon genes (STING) signaling pathway and ferritinophagy in the early stage of cerebral ischemia-reperfusion (I/R) in mice.Methods:Twenty-four clean-grade healthy male C57BL/6 mice, aged 6-8 weeks, weighing 21-25 g, were divided into 4 groups ( n=6 each) using a random number table method: sham group, cerebral I/R injury group (CIRI group), cerebral I/R injury + cGAS inhibitor group (CIRI + RU group), and cerebral I/R injury + cGAS inhibitor + overexpressed nuclear receptor coactivator 4 (NCOA4) group (MCAO + RU + LV-NCOA4 group). The model of cerebral I/R injury was developed using the middle cerebral artery occlusion (MCAO) in anesthetized animals.In CIRI+ RU group, cGAS inhibitor 5 mg/kg was intraperitoneally injected at 10 min before reperfusion.In CIRI+ RU+ LV-NCOA4 group, NCOA4-overexpressing lentivirus (1×10 9 TU/ml) 2 μl was injected into the ventricle at 7 days before MCAO, and the other operations were the same as those previously described in CIRI+ RU group.After 6 h of reperfusion, the neurological function deficits were assessed and scored, then the mice were sacrificed, and brains were removed for determination of the cerebral infarct size (by TTC method), MDA content (by TBA method), activity of SOD (by WST-1 method), and expression of cGAS, STING, NCOA4, ferritin, and microtubule-associated protein 1 light chain 3B (LC3B) (by Western blot). Results:Compared with Sham group, the neurological function deficit score and cerebral infarct size were significantly increased, SOD activity was decreased, MDA content was increased, the expression of cGAS, STING, NCOA4 and LC3B was up-regulated, and the expression of ferritin was down-regulated in CIRI group ( P<0.05). Compared with CIRI group, the neurological function deficit score and cerebral infarct size were significantly decreased, SOD activity was increased, MDA content was decreased, the expression of cGAS, STING, NCOA4 and LC3B was down-regulated, and the expression of ferritin was up-regulated in CIRI+ RU group ( P<0.05). Compared with CIRI+ RU group, the neurological function deficit score and cerebral infarct size were significantly increased, SOD activity was decreased, MDA content was increased, the expression of cGAS, STING, NCOA4 and LC3B was up-regulated, and the expression of ferritin was down-regulated in CIRI group ( P<0.05), and no significant change was found in the expression of cGAS and STING in CIRI+ RU+ LV-NCOA4 group ( P>0.05). Conclusions:The cGAS-STING signaling pathway can promote the over-activation of ferritinophagy, enhance oxidative stress, and thus induce early CIRI in mice.