Rosmarinic acid（RA） can elicit a neuroprotective effect against ischemic stroke, but the precise molecular mechanism remains poorly understood. In this study, an experimental ischemic stroke model was established in...Rosmarinic acid（RA） can elicit a neuroprotective effect against ischemic stroke, but the precise molecular mechanism remains poorly understood. In this study, an experimental ischemic stroke model was established in CD-1 mice（Beijing Vital River Laboratory Animal Technology, Beijing, China） by occluding the right middle cerebral artery for 1 hour and allowing reperfusion for 24 hours. After intraperitoneally injecting model mice with 10, 20, or 40 mg/kg RA, functional neurological deficits were evaluated using modified Longa scores. Subsequently, cerebral infarct volume was measured using TTC staining and ischemic brain tissue was examined for cell apoptosis with TUNEL staining. Superoxide dismutase activity and malondialdehyde levels were measured by spectrophometry. Expression of heme oxygenase-1（HO-1）, nuclear factor erythroid 2-related factor 2（Nrf2）, Bcl-2, Bax, Akt, and phospho-Ser473 Akt proteins in ischemic brain tissue was detected by western blot, while mRNA levels of Nrf2, HO-1, Bcl-2, and Bax were analyzed using real time quantitative PCR. In addition, HO-1 enzyme activity was measured spectrophotometrically. RA（20 and 40 mg/kg） greatly improved neurological function, reduced infarct volume, decreased cell apoptosis, upregulated Bcl-2 protein and mRNA expression, downregulated Bax protein and mRNA expression, increased HO-1 and Nrf2 protein and mRNA expression, increased superoxide dismutase activity, and decreased malondialdehyde levels in ischemic brain tissue of model mice. However, intraperitoneal injection of a HO-1 inhibitor（10 mg/kg zinc protoporphyrin IX） reversed the neuroprotective effects of RA on HO-1 enzyme activity and Bcl-2 and Bax protein expression. The PI3 K/Akt signaling pathway inhibitor LY294002（10 mM） inhibited Akt phosphorylation, as well as Nrf2 and HO-1 expression. Our findings suggest that RA has anti-oxidative and anti-apoptotic properties that protect against ischemic stroke by a mechanism involving upregulation of Nrf2 and HO-1 expression via the PI3 K/Akt signaling pathway.展开更多
目的探讨弱氧化性低密度脂蛋白(minimally modified low density lipoprotein,mmLDL)上调在体小鼠肠系膜动脉ETA受体的作用(endothelin type A receptors,ETA)并考察自噬是否参与这一过程。方法小鼠尾静脉注射mmLDL,腹腔注射ClassⅢPI3...目的探讨弱氧化性低密度脂蛋白(minimally modified low density lipoprotein,mmLDL)上调在体小鼠肠系膜动脉ETA受体的作用(endothelin type A receptors,ETA)并考察自噬是否参与这一过程。方法小鼠尾静脉注射mmLDL,腹腔注射ClassⅢPI3K自噬通路抑制剂6-氨基-3-甲基嘌呤(3-methyladenine,3-MA),探究自噬在mmLDL给药处理小鼠中的作用,微血管张力描记仪观察内皮素-1(endothelin-1,ET-1)引起的小鼠肠系膜动脉收缩量效曲线的变化,RT-PCR定量ETA受体mRNA,Western blot检测ETA受体和ClassⅢPI3K、Beclin-1、LC3-Ⅱ/Ⅰ、p62及p-NF-κB、NF-κB的蛋白水平表达。结果mmLDL引起ET-1收缩量效曲线明显增强,表现为Emax值由生理盐水(NS)组的(184.87±7.46)%上升为(319.91±20.31)%(P<0.001),pEC50值由NS组的(8.05±0.05)上升为(9.11±0.09)(P<0.01)。mmLDL在上调ClassⅢPI3K、beclin-1、LC3-Ⅱ/Ⅰ和下调p62蛋白水平的同时,也引起ETA受体mRNA水平、蛋白表达明显增加,增加了p-NF-κB的蛋白水平;腹腔注射3-MA抑制了mmLDL的这些作用。结论mmLDL能通过ClassⅢPI3K/Beclin-1通路激活自噬及下游NF-κB通路上调ETA受体。展开更多
基金supported by the National Natural Science Foundation of China,No.81571292(to XJZ)、81601152(to YY)the Natural Science Foundation of Hebei Province of China,No.H2017206338(to RC)
文摘Rosmarinic acid（RA） can elicit a neuroprotective effect against ischemic stroke, but the precise molecular mechanism remains poorly understood. In this study, an experimental ischemic stroke model was established in CD-1 mice（Beijing Vital River Laboratory Animal Technology, Beijing, China） by occluding the right middle cerebral artery for 1 hour and allowing reperfusion for 24 hours. After intraperitoneally injecting model mice with 10, 20, or 40 mg/kg RA, functional neurological deficits were evaluated using modified Longa scores. Subsequently, cerebral infarct volume was measured using TTC staining and ischemic brain tissue was examined for cell apoptosis with TUNEL staining. Superoxide dismutase activity and malondialdehyde levels were measured by spectrophometry. Expression of heme oxygenase-1（HO-1）, nuclear factor erythroid 2-related factor 2（Nrf2）, Bcl-2, Bax, Akt, and phospho-Ser473 Akt proteins in ischemic brain tissue was detected by western blot, while mRNA levels of Nrf2, HO-1, Bcl-2, and Bax were analyzed using real time quantitative PCR. In addition, HO-1 enzyme activity was measured spectrophotometrically. RA（20 and 40 mg/kg） greatly improved neurological function, reduced infarct volume, decreased cell apoptosis, upregulated Bcl-2 protein and mRNA expression, downregulated Bax protein and mRNA expression, increased HO-1 and Nrf2 protein and mRNA expression, increased superoxide dismutase activity, and decreased malondialdehyde levels in ischemic brain tissue of model mice. However, intraperitoneal injection of a HO-1 inhibitor（10 mg/kg zinc protoporphyrin IX） reversed the neuroprotective effects of RA on HO-1 enzyme activity and Bcl-2 and Bax protein expression. The PI3 K/Akt signaling pathway inhibitor LY294002（10 mM） inhibited Akt phosphorylation, as well as Nrf2 and HO-1 expression. Our findings suggest that RA has anti-oxidative and anti-apoptotic properties that protect against ischemic stroke by a mechanism involving upregulation of Nrf2 and HO-1 expression via the PI3 K/Akt signaling pathway.
文摘目的探讨弱氧化性低密度脂蛋白(minimally modified low density lipoprotein,mmLDL)上调在体小鼠肠系膜动脉ETA受体的作用(endothelin type A receptors,ETA)并考察自噬是否参与这一过程。方法小鼠尾静脉注射mmLDL,腹腔注射ClassⅢPI3K自噬通路抑制剂6-氨基-3-甲基嘌呤(3-methyladenine,3-MA),探究自噬在mmLDL给药处理小鼠中的作用,微血管张力描记仪观察内皮素-1(endothelin-1,ET-1)引起的小鼠肠系膜动脉收缩量效曲线的变化,RT-PCR定量ETA受体mRNA,Western blot检测ETA受体和ClassⅢPI3K、Beclin-1、LC3-Ⅱ/Ⅰ、p62及p-NF-κB、NF-κB的蛋白水平表达。结果mmLDL引起ET-1收缩量效曲线明显增强,表现为Emax值由生理盐水(NS)组的(184.87±7.46)%上升为(319.91±20.31)%(P<0.001),pEC50值由NS组的(8.05±0.05)上升为(9.11±0.09)(P<0.01)。mmLDL在上调ClassⅢPI3K、beclin-1、LC3-Ⅱ/Ⅰ和下调p62蛋白水平的同时,也引起ETA受体mRNA水平、蛋白表达明显增加,增加了p-NF-κB的蛋白水平;腹腔注射3-MA抑制了mmLDL的这些作用。结论mmLDL能通过ClassⅢPI3K/Beclin-1通路激活自噬及下游NF-κB通路上调ETA受体。
