title: The Mechanism of Long Non-coding RNA MEG3 for Neurons Apoptosis Caused by Hypoxia: Mediated by miR-181b-12/15-LOX Signaling Pathway.
abstract: OBJECTIVE
  lncRNAs are recently thought to play a significant role in cellular homeostasis during pathological process of diseases by competing inhibiting miRNA function. The aim of present study was to assess the function of long non-coding RNA (lncRNA) MEG3 and its functional interaction with microRNA-181b in cerebral ischemic infarct of mice and hypoxia-induced neurons apoptosis.
  
  
  METHODS
  To address this question, we performed the experiments with in vivo middle cerebral artery occlusion (MCAO) mice model and in vitro oxygen-glucose deprivation (OGD)-cultured neuronal HT22 cell line. Relative expression of MEG3, miR-181b, and 12/15-LOX (lipoxygenase) mRNA was determined using quantitative RT-PCR. Western blot was used to evaluate 12/15-LOX protein expression. TUNEL assay was performed to assess cell apoptosis.
  
  
  RESULTS
  In both MCAO mice and OGD-cultured HT22 cell, ischemia, or hypoxia treatment results in a time-dependent increase in MEG3 and 12/15-LOX expression and decrease in miR-181b expression. Knockdown of MEG3 contributes to attenuation of hypoxia-induced apoptosis of HT22 cell. Also, expression level of MEG3 negatively correlated with miR-181b expression and positively correlated with 12/15-LOX expression. In contrary to MEG3, miR-181b overexpression attenuated hypoxia-induced HT22 cell apoptosis, as well as suppressed hypoxia-induced increase in 12/15-LOX expression. By luciferase reporter assay, we concluded that miR-181b directly binds to 12/15-LOX 3'-UTR, thereby negatively regulates 12/15-LOX expression.
  
  
  CONCLUSIONS
  Our data suggested that long non-coding RNA MEG3 functions as a competing endogenous RNA for miR-181b to regulate 12/15-LOX expression in middle cerebral artery occlusion-induced ischemic infarct of brain nerve cells.
authors.affiliation: Department of Neurology, Qianfoshan Hospital, Shandong University Jinan, China.
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Pharmacological Laboratory, Shandong Academy of Chinese Medicine Jinan, China.
authors.forename: Lijing
authors.initials: L
authors.lastname: Hou
authors.affiliation: Department of Neurology, Qianfoshan Hospital, Shandong University Jinan, China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Huang
authors.affiliation: Department of Neurology, Qianfoshan Hospital, Shandong University Jinan, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Department of Neurology, Qianfoshan Hospital, Shandong University Jinan, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Lv
authors.affiliation: Department of Neurology, Qianfoshan Hospital, Shandong University Jinan, China.
authors.forename: Jiyou
authors.initials: J
authors.lastname: Tang
keywords: 12/15-LOX; MCAO; MEG3; infarct; miR-181b