Objective To investigate the changes in microglia phenotype after cerebral ischemia reperfusion(1R)injury and the effects of adenosine on nerve injury of cerebral IR injured rats.Methods Thirty-six healthy male Sprague Dawley rats were randomly divided into the sham operation(Sham)group,IR group,and adenosine pretreatment(AP)group,with 12 rats in each group.Before modeling,rats in the AP group were intraperitoneally injected with 2 mL of adenosine injection daily for 3 consecutive days,and rats in the Sham group and IR group were intraperitoneally injected with 2 mL of normal saline daily for 3 consecutive days.The middle cerebral artery occlusion models of rats in the IR group and AP group were constructed by using the suture-occluded method,and only the carotid artery of rats was isolated in the Sham group without ligation of blood vessels.At 2 hours after modeling,the neuroethology of rats in each group were evaluated according to a 5-point neurobehavioral scale.At 24 hours after restoring the blood perfusion in the middle cerebral artery,the rats in each group were executed,and their brain tissues were removed.The morphological changes of the brain tissues in the ischemic penumbra region were observed after hematoxylin-eosin(HE)staining.The co-expression of M1-type microglia markers and M2-type microglia markers was detected by immunofluorescence staining.The relative expression levels of pro-inflammatory factors inducible nitric oxide synthase(iNOS),tumor necrosis factor-α(TNF-α)and interleukin(IL)-1β released by M1-type microglia,and anti-inflammatory factors IL-4,IL-10 and transforming growth factor-β(TGF-β)released by M2-type microglia were detected by quantitative real-time polymerase chain reaction(qRT-PCR).Results The neurobehavioral scores of rats in the IR group and AP group were significantly higher than those in the Sham group,and the neurobehavioral score of rats in the IR group was significantly higher than that in the AP group(P＜0.05).HE staining results showed that the brain cells of rats in the Sham group were structurally complete and tightly arranged,with visible nuclei and no interstitial edema;the brain cells of rats in the IR group were structurally damaged and irregularly arranged,with loose cytoplasm and vacuoles in the cytosome;the structure of brain cells of rat in the AP group was better than that in the IR group,and there were many regularly-arranged normal cells,with complete nuclei.Immunofluorescence staining results showed that the number of M1-type and M2-type microglia in the ischemic penumbra region of rats in the IR group and AP group was significantly higher than that in the Sham group;the number of M1-type microglia in the IR group was significantly higher than that in the AP group,and the number of M2-type microglia was significantly lower than that in the AP group(P＜0.05).qRT-PCR results showed that the relative expression levels of pro-inflammatory cytokines TNF-α,IL-1β,iNOS and anti-inflammatory cytokines IL-4,IL-10,TGF-β in the IR group and AP group were significantly higher than those in the Sham group(P＜0.05);the relative expression levels of pro-inflammatory factors TNF-α,IL-1β and iNOS in the AP group were significantly lower than those in the IR group(P＜0.05),while the relative expression levels of anti-inflammatory factors IL-4,IL-10 and TGF-β were significantly higher than those in the IR group(P＜0.05).Conclusion AP can promote the polarization of microglia from M1 type to M2 type,inhibit the release of pro-inflammatory factors,increases the expression of anti-inflammatory factors,and thus has a neuroprotective effect on rats after cerebral IR injury.
维普
万方数据
