title: Up-regulation of microRNAs in brain of human alcoholics.
abstract: BACKGROUND
  MicroRNAs (miRNAs) are small, noncoding oligonucleotides with an important role in posttranscriptional regulation of gene expression at the level of translation and mRNA degradation. Recent studies have revealed that miRNAs play important roles in a variety of biological processes, such as cell proliferation, neuronal differentiation, developmental timing, synapse function, and neurogenesis. A single miRNA can target hundreds of mRNA transcripts for either translation repression or degradation, but the function of many human miRNAs is not known.
  
  
  METHODS
  miRNA array analysis was performed on the prefrontal cortex of 27 individual human cases (14 alcoholics and 13 matched controls). Target genes for differentially expressed miRNAs were predicted using multiple target prediction algorithms and a consensus approach, and predicted targets were matched against differentially expressed mRNAs from the same samples. Over- and under-representation analysis was performed using hypergeometric probability and z-score tests.
  
  
  RESULTS
  Approximately 35 miRNAs were significantly up-regulated in the alcoholic group compared with controls. Target prediction showed a large degree of overlap with our published cDNA microarray data. Functional classification of the predicted target genes of the regulated miRNAs includes apoptosis, cell cycle, cell adhesion, nervous system development, and cell-cell signaling.
  
  
  CONCLUSIONS
  These data suggest that the reduced expression of genes in human alcoholic cases may be because of the up-regulated miRNAs. Cellular processes fundamental to neuronal plasticity appear to represent major targets of the suggested miRNA regulation.
authors.affiliation: School of Medical Science & Griffith Health Institute, Griffith University, Southport, Australia.
authors.forename: Joanne M
authors.initials: JM
authors.lastname: Lewohl
authors.forename: Yury O
authors.initials: YO
authors.lastname: Nunez
authors.forename: Peter R
authors.initials: PR
authors.lastname: Dodd
authors.forename: Gayatri R
authors.initials: GR
authors.lastname: Tiwari
authors.forename: R Adron
authors.initials: RA
authors.lastname: Harris
authors.forename: R Dayne
authors.initials: RD
authors.lastname: Mayfield
mesh_terms: D057229:Alcoholics; D000437:Alcoholism / Q000378:metabolism*; D017209:Apoptosis; D001921:Brain / Q000378:metabolism*; D016022:Case-Control Studies; D002448:Cell Adhesion; D002453:Cell Cycle; D005625:Frontal Lobe / Q000378:metabolism; D006801:Humans; D035683:MicroRNAs / Q000378:metabolism*; D009473:Neuronal Plasticity; D015398:Signal Transduction; D015854:Up-Regulation / Q000502:physiology*
chemical_list: D035683:MicroRNAs