利拉鲁肽对百草枯诱导的小鼠帕金森病模型炎症及线粒体融合/分裂的影响

Effects of liraglutide on inflammation and mitochondrial fusion/division in Parkinson’s disease model of mice induced by paraquat

目的 探讨利拉鲁肽对百草枯(PQ)诱导的帕金森病(PD)小鼠模型保护作用以及作用机制。方法 24只昆明种小鼠随机分为对照组、PQ组、PQ+利拉鲁肽组,每组8只。通过连续5 d腹腔注射PQ (10 mg/kg)复制PD小鼠模型,连续7 d腹腔注射利拉鲁肽(50 nmol/kg)进行干预。采用行为学方法检测小鼠自主活动能力;免疫荧光观察酪氨酸羟化酶(TH)、离子钙接头蛋白分子1(Iba1)阳性细胞数;Western blotting检测TH、胶质纤维酸性蛋白(GFAP)、线粒体融合基因2(Mfn2)、线粒体动力相关蛋白1(Drp1)蛋白的表达。结果 与对照组相比,PQ组站立次数极显著减少(P<0.01),活动次数显著减少(P<0.05),黑质TH阳性细胞数、TH蛋白表达极显著减少(P<0.01),Iba1阳性细胞数、GFAP蛋白表达极显著增加(P<0.01),Drp1蛋白表达显著增加(P<0.05),Mfn2蛋白表达显著降低(P<0.05)。经利拉鲁肽干预后,与对照组相比,PQ+利拉鲁肽组TH阳性细胞数显著降低(P<0.05);与PQ组相比,PQ+利拉鲁肽组小鼠站立次数、活动次数显著增加(P<0.05),TH阳性细胞数、TH蛋白表达极显著增加(P<0.01),Iba1阳性细胞数极显著减少(P<0.01),GFAP蛋白表达显著减少(P<0.05),Drp1蛋白表达极显著减少(P<0.01),Mfn2蛋白表达极显著增加(P<0.01)。结论 利拉鲁肽能减轻PQ诱导的PD模型小鼠黑质神经炎症,调节线粒体融合、分裂,减少多巴胺能神经元的丢失,具有神经保护作用。

Objective To investigate the protective effect and mechanism of liraglutide on the paraquat(PQ)-induced Parkinson's disease(PD) mouse model. Methods Totally 24 Kunming mice were randomly divided into control group, PQ group and PQ +liraglutide group, 8 mice in each group. PD model was established by intraperitoneal injection of PQ(10 mg/kg) for 5 consecutive days, and liraglutide(50 nmol/kg) was injected intraperitoneally for 7 consecutive days. The free-standing and locomotor activity of mice were measured by behavioral method. Immunofluorescence was used to observe the number of tyrosine hydroxylase(TH) and ionized calcium binding adaptor molecule 1(Iba1) immunoreactive cells. Western blotting was used to detect the expression of protein TH, glial fibrillary acidic protein(GFAP), mitofusin-2(Mfn2) and dynamin-related protein 1(Drp1). Results The numbers of free-standing and locomotor activity numbers decreased significantly(P<0.01, P<0.05) in PQ group compared with the control group, and the number of TH immunoreactive cells and TH protein expression in substantia nigra decreased significantly(P<0.01, P<0.01) compared with the control group, while the number of Iba1 immunoreactive cells and GFAP protein expression increased significantly(P<0.01, P<0.01) compared with the control group;the expression of Drp1 protein in PQ group was significantly higher than that in control group(P<0.05), while the Mfn2 protein expression decreased significantly(P<0.05) compared with the control group. After treatment with liraglutide, the number of TH positive cells in PQ + liraglutide group was significantly lower than that in control group(P<0.05);the numbers of free-standing and locomotor activity increased significantly(P<0.05, P<0.05) in PQ + liraglutide group compared with the PQ group, and the number of TH positive cells and expression of TH protein in PQ + liraglutide group were significantly higher than that in PQ group(P<0.01, P<0.01);while the number of Iba1 positive cells and GFAP protein expression decreased significantly(P<0.01, P<0.05) compared with the PQ group;the Drp1 protein expression decreased significantly(P<0.01) compared with the PQ group, while the expression of Mfn2 protein in PQ + liraglutide group was significantly higher than that in PQ group(P<0.01). Conclusion Liraglutide has neuroprotective effect by reducing neuroinflammation in substantia nigra, regulating mitochondrial fusion and fission.