OBJECTIVE Oleoylethanolamide(OEA) is an endogenous peroxisome proliferatoractivated receptor alpha(PPARα) agonist that acts on the peripheral control of energy metabolism.Previous studies have shown that OEA exerts n...OBJECTIVE Oleoylethanolamide(OEA) is an endogenous peroxisome proliferatoractivated receptor alpha(PPARα) agonist that acts on the peripheral control of energy metabolism.Previous studies have shown that OEA exerts neuroprotection after cerebral ischemia.However,whether OEA affects the outcomes of diabetes-induced encephalopathy(DE) requires further study.METHODS The chronic effects of OEA on DE were evaluated in C57BL/6 and PPARαknockout mice,individually.The cognitive function was assessed with Morris water maze.The expression of receptor for advanced glycation end products(RAGE) and phosphorylation of Tau in mice hippocampus were determined using Western blotting.The influence of OEA in neuron loss and neuroplasticity were assessed with immunofluorescent staining and Western blotting.RESULTS OEA markedly ameliorated performance in the Morris water maze,which was correlated with its capabilities of suppressing glycometabolism and phosphorylation of Tau in the hippocampus.OEA offered protection from diabetes-induced impairments in hippocampal neuroplasticity.Furthermore,the changes in Morris water maze performance and neuron loss could not be observed in PPARα knockout mouse models with OEA administration.CONCLUSION The ability of OEA to control PPARα signaling can serve as a novel neuroprotective approach for the treatment of diabetes-induced encephalopathy.展开更多
目的:研究O-GlcNAcylation调节蛋白激酶C受体1(receptor for activated C kinase 1,Rack1)的稳定性在SHH型髓母细胞瘤(SHH type medulloblastoma,SHH-MB)形成中的功能作用。方法:选取中国人民解放军西部战区总医院临床肿瘤标本库中分子...目的:研究O-GlcNAcylation调节蛋白激酶C受体1(receptor for activated C kinase 1,Rack1)的稳定性在SHH型髓母细胞瘤(SHH type medulloblastoma,SHH-MB)形成中的功能作用。方法:选取中国人民解放军西部战区总医院临床肿瘤标本库中分子分型所确定的SHH-MB肿瘤及癌旁组织,分析样本中Rack1和O-GlcNAcylation(O-Glc NAc)的表达水平差异。对于人源髓母细胞瘤细胞系Daoy使用糖基化转移酶(OGT)抑制剂(OSMI-1)和去糖基化转移酶(OGA)抑制剂(TM-G)进行处理,通过Cell Counting Kit-8(CCK-8)法和免疫荧光染色检测肿瘤细胞增殖能力。采用O-Glc NAc酶标记系统、免疫共沉淀(Co-IP)和Western blot法判断Rack1有无发生O-Glc NAc,而后通过环己酰亚胺(CHX)实验和泛素化修饰实验证实O-GlcNAcylation对Rack1蛋白水平的影响。构建敲低Rack1的髓母细胞瘤模型,通过Cell Counting Kit-8(CCK-8)法、免疫荧光染色和划痕实验检测肿瘤细胞增殖能力。同时通过在免疫缺陷型小鼠进行异种原位肿瘤移植进行验证,在所得组织样本中(sh-NC和shRack1)使用Western blot检测下游SHH信号通路变化。结果:Rack1和O-GlcNAcylation在SHH-MB中表达水平显著增高,且Rack1表达水平和患者生存率呈负相关关系。对Daoy细胞系使用OSMI-1、TM-G处理后,发现O-Glc NAc能明显促进Daoy细胞增殖,而抑制细胞O-GlcNAc则抑制细胞增殖。分子实验证实Rack1蛋白O-GlcNAcylation可以调节其蛋白稳定性,进而促进肿瘤细胞增殖。在Daoy细胞系敲低Rack1表达,其细胞增殖能力明显低于对照组;在动物水平方面,相较于对照组,Rack1蛋白敲低的肿瘤组织增殖受到显著抑制。并且Rack1可通过调节SHH信号通路参与SHH-MB形成。结论:O-GlcNAcylation可通过调节Rack1蛋白的稳定性进而参与SHH-MB形成。展开更多
OBJECTIVE Astrocytes activa⁃tion and glial scar formation are the important causes that hinder the recovery of motor function after cerebral ischemia.However,its precise mechanism has not been clarified.Peroxisome pro...OBJECTIVE Astrocytes activa⁃tion and glial scar formation are the important causes that hinder the recovery of motor function after cerebral ischemia.However,its precise mechanism has not been clarified.Peroxisome proliferator-activated receptorα(PPARα)is a ligand-activated nuclear transcriptional factor.This study aims to further clarify the role of PPARαin astrocyte activation after cerebral isch⁃emia and explore the underlying mechanism.METHODS Astrocyte activation in vivo model was induced by transient middle cerebral artery occlusion(tMCAO)in mice and in vitro model was induced by oxygen-glucose deprivation/reox⁃ygenation(OGD/R)in primary culture of mouse astrocyte.The effects of PPARαon astrocyte ac⁃tivation and autophagy flux were observed in the condition of PPARαdysfunction(PPARαnull mice)or PPARαactivation by oleoylethanol⁃amide(OEA).RESULTS PPARαmainly ex⁃pressed in activated astrocytes during the chron⁃ic phase of brain ischemia and PPARαdysfunc⁃tion promoted astrocytes activation after brain ischemia in vivo and in vitro.After cerebral isch⁃emia,the expressions of LC3-Ⅱ/Ⅰand P62 both increased in the brain tissue near the infarct core.Autophagic vesicles accumulation was ob⁃served by electron microscopy in astrocytes,and mRFP-GFP-LC3 adenovirus infection assay indi⁃cated the block of autophagy flux.PPARαdys⁃function aggravated autophagy flux block,while PPARαactivation preserved the lysosome func⁃tion and restored autophagy flux in astrocytes after OGD/R.Autophagy flux blocker bafilomycin A1 and chloroquine antagonized the effect of OEA on inhibiting astrocyte activation.CONCLU⁃SION PPARαactivation inhibites the over-activa⁃tion of astrocytes by restoring the autophagy flux after cerebral ischemia.展开更多
基金Fun-damental Research Funds for the Central Universities (20720180042)Health Science ResearchPersonnel Training Program of Fujian Province(2018-CXB-30)+2 种基金Natural Science Foundation of Fujian, China (2016J014152016D024)Science and Technology Project of Xi
文摘OBJECTIVE Oleoylethanolamide(OEA) is an endogenous peroxisome proliferatoractivated receptor alpha(PPARα) agonist that acts on the peripheral control of energy metabolism.Previous studies have shown that OEA exerts neuroprotection after cerebral ischemia.However,whether OEA affects the outcomes of diabetes-induced encephalopathy(DE) requires further study.METHODS The chronic effects of OEA on DE were evaluated in C57BL/6 and PPARαknockout mice,individually.The cognitive function was assessed with Morris water maze.The expression of receptor for advanced glycation end products(RAGE) and phosphorylation of Tau in mice hippocampus were determined using Western blotting.The influence of OEA in neuron loss and neuroplasticity were assessed with immunofluorescent staining and Western blotting.RESULTS OEA markedly ameliorated performance in the Morris water maze,which was correlated with its capabilities of suppressing glycometabolism and phosphorylation of Tau in the hippocampus.OEA offered protection from diabetes-induced impairments in hippocampal neuroplasticity.Furthermore,the changes in Morris water maze performance and neuron loss could not be observed in PPARα knockout mouse models with OEA administration.CONCLUSION The ability of OEA to control PPARα signaling can serve as a novel neuroprotective approach for the treatment of diabetes-induced encephalopathy.
基金National Natural Science Foundation of China(81603093)and the Open Research Fund of State Key Laboratory of Cellu⁃lar Stress Biology,Xiamen University(SKLC⁃SB2019KF016)。
文摘OBJECTIVE Astrocytes activa⁃tion and glial scar formation are the important causes that hinder the recovery of motor function after cerebral ischemia.However,its precise mechanism has not been clarified.Peroxisome proliferator-activated receptorα(PPARα)is a ligand-activated nuclear transcriptional factor.This study aims to further clarify the role of PPARαin astrocyte activation after cerebral isch⁃emia and explore the underlying mechanism.METHODS Astrocyte activation in vivo model was induced by transient middle cerebral artery occlusion(tMCAO)in mice and in vitro model was induced by oxygen-glucose deprivation/reox⁃ygenation(OGD/R)in primary culture of mouse astrocyte.The effects of PPARαon astrocyte ac⁃tivation and autophagy flux were observed in the condition of PPARαdysfunction(PPARαnull mice)or PPARαactivation by oleoylethanol⁃amide(OEA).RESULTS PPARαmainly ex⁃pressed in activated astrocytes during the chron⁃ic phase of brain ischemia and PPARαdysfunc⁃tion promoted astrocytes activation after brain ischemia in vivo and in vitro.After cerebral isch⁃emia,the expressions of LC3-Ⅱ/Ⅰand P62 both increased in the brain tissue near the infarct core.Autophagic vesicles accumulation was ob⁃served by electron microscopy in astrocytes,and mRFP-GFP-LC3 adenovirus infection assay indi⁃cated the block of autophagy flux.PPARαdys⁃function aggravated autophagy flux block,while PPARαactivation preserved the lysosome func⁃tion and restored autophagy flux in astrocytes after OGD/R.Autophagy flux blocker bafilomycin A1 and chloroquine antagonized the effect of OEA on inhibiting astrocyte activation.CONCLU⁃SION PPARαactivation inhibites the over-activa⁃tion of astrocytes by restoring the autophagy flux after cerebral ischemia.
