title: Alteration of microRNA expression in cerebrospinal fluid of unconscious patients after traumatic brain injury and a bioinformatic analysis of related single nucleotide polymorphisms.
abstract: OBJECTIVE
  It is becoming increasingly clear that genetic factors play a role in traumatic brain injury (TBI), whether in modifying clinical outcome after TBI or determining susceptibility to it. MicroRNAs are small RNA molecules involved in various pathophysiological processes by repressing target genes at the post- transcriptional level, and TBI alters microRNA expression levels in the hippocampus and cortex. This study was designed to detect differentially expressed microRNAs in the cerebrospinal fluid (CSF) of TBI patients remaining unconscious two weeks after initial injury and to explore related single nucleotide polymorphisms (SNPs).
  
  
  METHODS
  We used a microarray platform to detect differential microRNA expression levels in CSF samples from patients with post-traumatic coma compared with samples from controls. A bioinformatic scan was performed covering microRNA gene promoter regions to identify potential functional SNPs.
  
  
  RESULTS
  Totally 26 coma patients and 21 controls were included in this study, with similar distribution of age and gender between the two groups. Microarray showed that fourteen microRNAs were differentially expressed, ten at higher and four at lower expression levels in CSF of traumatic coma patients compared with controls (p<0.05). One SNP (rs11851174 allele: C/T) was identified in the motif area of the microRNA hsa-miR-431-3P gene promoter region.
  
  
  CONCLUSIONS
  The altered microRNA expression levels in CSF after brain injury together with SNP identified within the microRNA gene promoter area provide a new perspective on the mechanism of impaired consciousness after TBI. Further studies are needed to explore the association between the specific microRNAs and their related SNPs with post-traumatic unconsciousness.
authors.affiliation: Department of Neurosurgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, People's Republic of China.
authors.forename: Wen-Dong
authors.initials: WD
authors.lastname: You
authors.forename: Qi-Lin
authors.initials: QL
authors.lastname: Tang
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Jin
authors.initials: J
authors.lastname: Lei
authors.forename: Jun-Feng
authors.initials: JF
authors.lastname: Feng
authors.forename: Qing
authors.initials: Q
authors.lastname: Mao
authors.forename: Guo-Yi
authors.initials: GY
authors.lastname: Gao
authors.forename: Ji-Yao
authors.initials: JY
authors.lastname: Jiang
mesh_terms: D000328:Adult; D000070642:Brain Injuries, Traumatic / Q000134:cerebrospinal fluid* / Q000235:genetics; D019295:Computational Biology; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000134:cerebrospinal fluid* / Q000235:genetics; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D014473:Unconscious, Psychology
chemical_list: D035683:MicroRNAs