title: Inhibition of autophagy via activation of PI3K/Akt pathway contributes to the protection of ginsenoside Rb1 against neuronal death caused by ischemic insults.
abstract: Lethal autophagy is a pathway leading to neuronal death caused by transient global ischemia. In this study, we examined the effect of Ginsenoside Rb1 (GRb1) on ischemia/reperfusion-induced autophagic neuronal death and investigated the role of PI3K/Akt. Ischemic neuronal death in vitro was induced by using oxygen glucose deprivation (OGD) in SH-SY5Y cells, and transient global ischemia was produced by using two vessels occlusion in rats. Cellular viability of SH-SY5Y cells was assessed by MTT assay, and CA1 neuronal death was evaluated by Hematoxylin-eosin staining. Autophagic vacuoles were detected by using both fluorescent microscopy in combination with acridine orange (AO) and Monodansylcadaverine (MDC) staining and transmission electronic microscopy. Protein levels of LC3II, Beclin1, total Akt and phosphor-Akt at Ser473 were examined by western blotting analysis. GRb1 inhibited both OGD and transient ischemia-induced neuronal death and mitigated OGD-induced autophagic vacuoles in SH-SY5Y cells. By contrast, PI3K inhibitor LY294002 counteracted the protection of GRb1 against neuronal death caused by either OGD or transient ischemia. LY294002 not only mitigated the up-regulated protein level of phosphor Akt at Ser473 caused by GRb1, but also reversed the inhibitory effect of GRb1 on OGD and transient ischemia-induced elevation in protein levels of LC3II and Beclin1.
authors.affiliation: Department of Neurology, First Hospital of Jilin University, Changchun 130021, China. luotianfei2010@126.com.
authors.forename: Tianfei
authors.initials: T
authors.lastname: Luo
authors.affiliation: Department of Pediatrics, Anzhen Hospital of Capital University of Medical Sciences, Beijing 10029, China. liugvying@126.com.
authors.forename: Guiying
authors.initials: G
authors.lastname: Liu
authors.affiliation: Department of Pathology, First Hospital of Jilin University, Changchun 130021, China. mahongxi1969@163.com.
authors.forename: Hongxi
authors.initials: H
authors.lastname: Ma
authors.affiliation: Department of Neurosurgery, First Hospital of Jilin University, Changchun 130021, China. Lubin03216@163.com.
authors.forename: Bin
authors.initials: B
authors.lastname: Lu
authors.affiliation: Department of Neurosurgery, First Hospital of Jilin University, Changchun 130021, China. xuhaiyang76@163.com.
authors.forename: Haiyang
authors.initials: H
authors.lastname: Xu
authors.affiliation: Department of Pediatrics, First Hospital of Jilin University, Changchun 130021, China. yujingwang2012@126.com.
authors.forename: Yujing
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Neurology, First Hospital of Jilin University, Changchun 130021, China. drwujiang2010@163.com.
authors.forename: Jiang
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Neurosurgery, First Hospital of Jilin University, Changchun 130021, China. pengfeige@gmail.com.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Ge
authors.affiliation: Department of Pediatrics, First Hospital of Jilin University, Changchun 130021, China. jakcyliangjm@163.com.
authors.forename: Jianmin
authors.initials: J
authors.lastname: Liang
mesh_terms: D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000096:biosynthesis / Q000235:genetics; D001343:Autophagy / Q000187:drug effects*; D000071186:Beclin-1; D002545:Brain Ischemia / Q000188:drug therapy* / Q000473:pathology; D056547:CA1 Region, Hippocampal / Q000098:blood supply / Q000473:pathology*; D045744:Cell Line, Tumor; D002867:Chromones / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D036145:Ginsenosides / Q000037:antagonists & inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D005947:Glucose / Q000494:pharmacology; D006801:Humans; D008297:Male; D008869:Microtubule-Associated Proteins / Q000096:biosynthesis / Q000235:genetics; D009025:Morpholines / Q000494:pharmacology; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics; D009447:Neuroblastoma / Q000473:pathology; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D018696:Neuroprotective Agents / Q000037:antagonists & inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D010100:Oxygen / Q000494:pharmacology; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology*; D008517:Phytotherapy; D051057:Proto-Oncogene Proteins c-akt / Q000502:physiology*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000188:drug therapy / Q000209:etiology / Q000517:prevention & control; D015398:Signal Transduction / Q000187:drug effects*; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D051017:Apoptosis Regulatory Proteins; D000071186:Beclin-1; D002867:Chromones; D036145:Ginsenosides; D005947:Glucose; D008869:Microtubule-Associated Proteins; D009025:Morpholines; D009419:Nerve Tissue Proteins; D018696:Neuroprotective Agents; D010100:Oxygen; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; C512829:Becn1 protein, rat; C526109:Anxa3 protein, rat; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; C442759:ginsenoside Rb1