title: p300 expression is induced by oxygen deficiency and protects neuron cells from damage.
abstract: Low oxygen level or oxygen deficiency (hypoxia) is a major factor causing neuronal damage in many diseases. Inducing cell adaptation to hypoxia is an effective method for neuroprotection that can be achieved by either inhibiting the death effectors or enhancing the survival factors. Transcription coactivator p300 is necessary for hypoxia-induced transcriptional activation and plays an important role in neuron survival. However, the alteration of p300 expression under hypoxia condition and its role in hypoxia-induced neuronal damage remain unclear. In this study, the distribution of p300 in rat brain and the alteration of its expression in rat hippocampus during hypobaric hypoxia exposure were detected. In addition, the role of p300 in neuronal-like PC12 cell damage induced by oxygen deficiency (3% oxygen) was evaluated. Our results showed that p300 protein was mainly expressed in the cells expressed beta-tubulin III in the cerebral cortex, hippocampus, cerebellum cortex, medulla oblongata and hypothalamus. Less or no positive signal of p300 expression was observed in beta-tubulin III negative cells. This indicated that p300 was predominantly expressed in neurons of rat brain. Furthermore, p300 expression was up-regulated in rat hippocampus during hypoxia exposure and in neuronal-like PC12 cells under 3% oxygen condition. Interestingly, neuronal-like PC12 cell damage induced by oxygen deficiency (3% oxygen) was increased by suppression of p300 expression with short hairpin RNA (shRNA). These data indicate that p300 is an important molecule for neuroprotection under hypoxia.
authors.affiliation: Department of Pathophysiology and High Altitude Physiology, College of High Altitude Medicine, Third Military Medical University, Chongqing 400038, China.
authors.forename: Xiao Ling
authors.initials: XL
authors.lastname: Tan
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhai
authors.forename: Wen Xiang
authors.initials: WX
authors.lastname: Gao
authors.forename: You Ming
authors.initials: YM
authors.lastname: Fan
authors.forename: Fu Yu
authors.initials: FY
authors.lastname: Liu
authors.forename: Qing Yuan
authors.initials: QY
authors.lastname: Huang
authors.forename: Yu Qi
authors.initials: YQ
authors.lastname: Gao
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D015687:Cell Hypoxia; D050881:E1A-Associated p300 Protein / Q000235:genetics / Q000378:metabolism*; D006624:Hippocampus / Q000378:metabolism; D000860:Hypoxia / Q000378:metabolism / Q000503:physiopathology*; D007150:Immunohistochemistry; D008297:Male; D009474:Neurons / Q000502:physiology*; D016716:PC12 Cells; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D014404:Tubulin / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D012333:RNA, Messenger; D014404:Tubulin; D050881:E1A-Associated p300 Protein; C494362:Ep300 protein, rat