title: Hypoxia/ischemia up-regulates Id2 expression in neuronal cells in vivo and in vitro.
abstract: Inhibitor of DNA binding/differentiation 2 (Id2) belongs to a family of transcriptional modulators characterized by a helix-loop-helix (HLH) motif that lacks the basic amino acid domain necessary to bind DNA. The aim of this study was to obtain a better understanding of the role of Id2 in hypoxia/ischemia (H/I)-induced neuronal apoptosis. Following H/I induction in a rat model of middle cerebral artery occlusion (MCAO)/reperfusion, the number of TUNEL-positive cells in cerebral cortices of the penumbra area increased gradually, while the Id2 mRNA and protein expression were also significantly up-regulated. The hypoxia-mimetic, cobalt chloride (CoCl2)-treated rat neuroblastoma B35 cell line also demonstrated enhanced Id2 mRNA and protein expression as well as increased number of cells in the sub-G1 populations after H/I exposure. Consistently, the expression of Bax, a proapoptotic protein, was also up-regulated in vivo and in vitro. Moreover, triple immunofluorescence demonstrated the obvious co-localization of Id2, TUNEL and NeuN in neurons of the penumbra area. These data suggest that H/I up-regulates Id2 expression in neuronal cells, and Id2 might play an important role in H/I-induced neuronal apoptosis.
authors.affiliation: Department of Neurosurgery, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China.
authors.forename: Liemei
authors.initials: L
authors.lastname: Guo
authors.forename: Jin
authors.initials: J
authors.lastname: Lan
authors.forename: Yingying
authors.initials: Y
authors.lastname: Lin
authors.forename: Pin
authors.initials: P
authors.lastname: Guo
authors.forename: Quanmin
authors.initials: Q
authors.lastname: Nie
authors.forename: Qing
authors.initials: Q
authors.lastname: Mao
authors.forename: Li
authors.initials: L
authors.lastname: Ren
authors.forename: Yongming
authors.initials: Y
authors.lastname: Qiu
mesh_terms: D000818:Animals; D017209:Apoptosis; D045744:Cell Line, Tumor; D002540:Cerebral Cortex / Q000098:blood supply / Q000378:metabolism / Q000473:pathology; D020925:Hypoxia-Ischemia, Brain / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D020244:Infarction, Middle Cerebral Artery / Q000150:complications; D051797:Inhibitor of Differentiation Protein 2 / Q000235:genetics / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: C497451:Id2 protein, rat; D051797:Inhibitor of Differentiation Protein 2; D012333:RNA, Messenger; D051028:bcl-2-Associated X Protein
keywords: Apoptosis; Hypoxia; Id2; Ischemia; Neuronal cell