大麻素受体激动剂ACEA通过调节IL-33促进脊髓损伤后髓鞘恢复

Cannabinoid receptor agonist ACEA promotes myelin recovery after spinal cord injury by regulating IL-33

目的探讨激活大麻素1型受体(CB1R)激动剂ACEA在小鼠脊髓损伤(SCI)后促进髓鞘恢复的保护作用,并明确白细胞介素33(IL-33)在其中的作用。方法脊髓胸10节段横断法对小鼠进行SCI造模,随机分为假手术组(Sham组)、SCI(0、3、7、14 d)+Saline组、SCI(3、7、14 d)+ACEA组和SCI 14 d+IL-33组,采用Western blotting测定损伤部位的髓鞘蛋白(MBP)和IL-33的表达水平;应用体外小鼠少突胶质前体细胞(OPC)原代培养氧糖剥夺(OGD)模型模拟SCI,分为对照组(Control组)、OGD 6 h组、OGD 6 h+ACEA组、OGD 6 h+IL-33组。免疫荧光观察ACEA对OPC分化的作用。结果与Sham组相比,SCI后小鼠脊髓组织中MBP蛋白显著减少(P<0.01),IL-33蛋白水平显著增加(P<0.01);SCI后给予ACEA可显著增加MBP和IL-33蛋白水平(P<0.05,P<0.01);SCI后给予IL-33后CC1的细胞占比显著增多(P<0.01)。与Control组细胞相比,OGD 6 h后OPC分化成熟标志物MBP的数目占比显著减少(P<0.01),但可显著增加OPC细胞中IL-33的荧光强度(P<0.01);OGD后给予ACEA可明显升高表达MBP的细胞占比(P<0.05)和IL-33的荧光强度(P<0.01);OGD后给予IL-33可显著增强OPC细胞中IL-33的荧光强度(P<0.05)。结论CB1R激动剂ACEA在小鼠SCI后可能通过在晚期上调IL-33的表达促进CC1成熟,髓鞘恢复。

Objective To investigate the protective effect of activating cannabinoid type 1 receptor(CB1R)agonist ACEA in promoting myelin recovery after spinal cord injury(SCI)in mice,and to clarify the role of interleukin-33(IL-33)in this effect.Methods SCI modeling was performed on the mice by 10-segment spinothoracic transsection method,and the mice were randomly divided into Sham group,SCI(0,3,7,14 d)+Saline group,SCI(3,7,14 d)+ACEA group and SCI 14 d+IL-33 group.The expression levels of myelin basic protein(MBP)and IL-33 at the injured site were determined by Western blotting.The in vitro oxygen-glucose deprivation(OGD)model of oligodendrocyte precursor cells(OPC)was used to simulate SCI and divided into Control group,OGD 6 h group,OGD 6 h+ACEA group and OGD 6 h+IL-33 group.The effect of ACEA on OPC differentiation was observed by immunofluorescence.Results Compared with Sham group,MBP protein decreased significantly(P<0.01)and IL-33 protein level increased significantly(P<0.01)in the spinal cord of mice after SCI.Administration of ACEA after SCI significantly increased MBP and IL-33 protein levels(P<0.05,P<0.01);After SCI,the percentage of CC1 cells increased significantly after administration of IL-33(P<0.01).Compared with the Control group,the proportion of MBP,a marker of OPC differentiation and maturation,decreased significantly(P<0.01),but the fluorescence intensity of IL-33 in OPC increased significantly(P<0.01)after 6 h of OGD.After OGD,administration of ACEA significantly increased the proportion of cells expressing MBP(P<0.05)and the fluorescence intensity of IL-33(P<0.01).Administration of IL-33 after OGD significantly enhanced the fluorescence intensity of IL-33 in OPC(P<0.05).Conclusion The CB1R agonist ACEA may promote CC1 maturation and myelin recovery in mice after SCI by up-regulating the expression of IL-33 at a late stage.