title: Cold-inducible RNA-binding protein inhibits neuron apoptosis through the suppression of mitochondrial apoptosis.
abstract: Cold-inducible RNA-binding protein (CIRP) is induced by mild hypothermia in several mammals, but the precise mechanism by which CIRP mediates hypothermia-induced neuroprotection remains unknown. We aimed to investigate the molecular mechanisms by which CIRP protects the nervous system during mild hypothermia. Rat cortical neurons were isolated and cultured in vitro under mild hypothermia (32°C). Apoptosis was measured by annexin V and propidium iodide staining, visualized by flow cytometry. Neuron ultrastructure was visualized by transmission electron microscopy. CIRP overexpression and knockdown were achieved via infection with pL/IRES/GFP-CIRP and pL/shRNA/F-CIRP-A lentivirus. RT(2) Profiler PCR Array Pathway Analysis and western blotting were used to evaluate the effects of CIRP overexpresion/knockdown on the neurons׳ transcriptome. Neuron late apoptosis was significantly reduced at day 7 of culture by 12h hypothermia, but neuron ultrastructure remained relatively intact. RT(2) Profiler PCR Array Pathway Analysis of 84 apoptosis pathway-associated factors revealed that mild hypothermia and CIRP overexpression induce similar gene expression profiles, specifically alterations of genes implicated in the mitochondrial apoptosis pathway. Mild hypothermia-treated neurons up-regulated 12 and down-regulated 38 apoptosis pathway-associated genes. CIRP-overexpressing neurons up-regulated 15 and down-regulated 46 genes. CIRP-knocked-down hypothermia-treated cells up-regulated 9 and down-regulated 40 genes. Similar results were obtained at the protein level. In conclusion, CIRP may inhibit neuron apoptosis through the suppression of the mitochondria apoptosis pathway during mild hypothermia.
authors.affiliation: Department of Neurosurgery, First Affiliated Hospital of Chinese PLA General Hospital, Beijing 100048, China.
authors.forename: Hai-Tao
authors.initials: HT
authors.lastname: Zhang
authors.affiliation: Department of Neurosurgery, First Affiliated Hospital of Chinese PLA General Hospital, Beijing 100048, China.
authors.forename: Jing-Hui
authors.initials: JH
authors.lastname: Xue
authors.affiliation: Department of Neurosurgery, First Affiliated Hospital of Chinese PLA General Hospital, Beijing 100048, China. Electronic address: zhangzhiwen0409@163.com.
authors.forename: Zhi-Wen
authors.initials: ZW
authors.lastname: Zhang
authors.affiliation: Department of Neurosurgery, First Affiliated Hospital of Chinese PLA General Hospital, Beijing 100048, China.
authors.forename: Hai-Bo
authors.initials: HB
authors.lastname: Kong
authors.affiliation: Department of Neurosurgery, First Affiliated Hospital of Chinese PLA General Hospital, Beijing 100048, China.
authors.forename: Ai-Jun
authors.initials: AJ
authors.lastname: Liu
authors.affiliation: Department of Neurosurgery, First Affiliated Hospital of Chinese PLA General Hospital, Beijing 100048, China.
authors.forename: Shou-Chun
authors.initials: SC
authors.lastname: Li
authors.affiliation: Laboratory of Genetic Engineering, The Military Medical Science Academy of the PLA, Beijing 100048, China.
authors.forename: Dong-Gang
authors.initials: DG
authors.lastname: Xu
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D015153:Blotting, Western; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000502:physiology / Q000648:ultrastructure; D057773:Cold Shock Proteins and Peptides / Q000235:genetics / Q000378:metabolism*; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D005822:Genetic Vectors; D007035:Hypothermia / Q000235:genetics / Q000473:pathology / Q000503:physiopathology; D016086:Lentivirus / Q000235:genetics; D046228:Microarray Analysis; D046529:Microscopy, Electron, Transmission; D008928:Mitochondria / Q000502:physiology* / Q000648:ultrastructure; D009474:Neurons / Q000502:physiology* / Q000648:ultrastructure; D016133:Polymerase Chain Reaction; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D017208:Rats, Wistar; D015854:Up-Regulation / Q000235:genetics
chemical_list: C585827:Cirbp protein, rat; D057773:Cold Shock Proteins and Peptides; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins
keywords: Apoptosis; Cold-inducible RNA-binding protein; Mild hypothermia; Neuron