title: N-Myc Downstream-Regulated Gene 2 (Ndrg2) Is Involved in Ischemia-Hypoxia-Induced Astrocyte Apoptosis: a Novel Target for Stroke Therapy.
abstract: Nearly all clinical trials that have attempted to develop effective strategies against ischemic stroke have failed, excluding those for thrombolysis, and most of these trials focused only on preventing neuronal loss. However, astrocytes have gradually become a target for neuroprotection in stroke. In previous studies, we showed that the newly identified molecular N-myc downstream-regulated gene 2 (Ndrg2) is specifically expressed in astrocytes in the brain and involved in some neurodegenerative diseases. However, the role of NDRG2 in ischemic stroke remained unclear. In this study, we investigated the role of NDRG2 in middle cerebral artery occlusion (MCAO)-induced focal cerebral ischemia and in oxygen-glucose deprivation (OGD)-induced cellular apoptosis in the M1800 astrocyte cell line. NDRG2 mRNA and protein expression began to increase at 6 and 2 h after reperfusion and peaked at 24 h in the ischemic penumbra and in M1800 cells, as detected by RT-PCR and Western blotting. Double immunofluorescence staining showed that the number of apoptotic cells increased as the NDRG2-positive signal increased and that the NDRG2 signal was sometimes co-localized with TUNEL-positive cells and translocated from the cytoplasm to the nucleus in both the ischemic penumbra and the M1800 cells. Using a lentivirus, we successfully constructed two stable astrocytic cell lines in which NDRG2 expression was significantly up- or down-regulated. NDRG2 silencing had a proliferative effect and reduced the percentage of apoptotic cells, reactive oxygen species (ROS) production, and cleaved Caspase-3 protein expression following OGD, whereas NDRG2 over-expression had the opposite effects. In conclusion, NDRG2 is involved in astrocyte apoptosis following ischemic-hypoxic injury, and inhibiting NDRG2 expression significantly reduces ROS production and astrocyte apoptosis. These findings provide insight into the role of NDRG2 in ischemic-hypoxic injury and provide potential targets for future clinical therapies for stroke.
authors.affiliation: Department of Anesthesiology, Xijing Hospital, The Fourth Military Medical University, Xi'an, 710032, China.
authors.forename: Yu-Long
authors.initials: YL
authors.lastname: Ma
authors.affiliation: First Affiliated Hospital to Chinese PLA General Hospital, Beijing, 100048, China.
authors.forename: Li-Xia
authors.initials: LX
authors.lastname: Zhang
authors.affiliation: Department of Anesthesiology, Xijing Hospital, The Fourth Military Medical University, Xi'an, 710032, China.
authors.forename: Guang-Lin
authors.initials: GL
authors.lastname: Liu
authors.affiliation: Department of Cardiology, Xijing Hospital, The Fourth Military Medical University, Xi'an, 710032, China.
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Fan
authors.affiliation: Department of Orthopaedics, Air Force General Hospital of PLA, Beijing, 100142, China. pengye1985@163.com.
authors.forename: Ye
authors.initials: Y
authors.lastname: Peng
authors.affiliation: Department of Anesthesiology, Xijing Hospital, The Fourth Military Medical University, Xi'an, 710032, China. gangwuhou@163.com.
authors.forename: Wu-Gang
authors.initials: WG
authors.lastname: Hou
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D017209:Apoptosis / Q000235:genetics; D001253:Astrocytes / Q000378:metabolism* / Q000473:pathology*; D002545:Brain Ischemia / Q000150:complications / Q000235:genetics / Q000473:pathology*; D053148:Caspase 3 / Q000378:metabolism; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D049109:Cell Proliferation; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D000860:Hypoxia / Q000150:complications / Q000235:genetics / Q000473:pathology*; D008297:Male; D008810:Mice, Inbred C57BL; D058990:Molecular Targeted Therapy; D021381:Protein Transport; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D015427:Reperfusion Injury / Q000150:complications / Q000235:genetics / Q000473:pathology; D020521:Stroke / Q000150:complications / Q000235:genetics / Q000473:pathology*; D013997:Time Factors; D015854:Up-Regulation
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D005904:Glial Fibrillary Acidic Protein; C485172:Ndr2 protein, mouse; D011506:Proteins; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D053148:Caspase 3
keywords: Apoptosis; Astrocyte; MCAO; Ndrg2; Neuroprotection; OGD