title: Co-regulation of intragenic microRNA miR-153 and its host gene Ia-2 β: identification of miR-153 target genes with functions related to IA-2β in pancreas and brain.
abstract: OBJECTIVE
  We analysed the genomic organisation of miR-153, a microRNA embedded in genes that encode two of the major type 1 diabetes autoantigens, islet-associated protein (IA)-2 and IA-2β. We also identified miR-153 target genes that correlated with IA-2β localisation and function.
  
  
  METHODS
  A bioinformatics approach was used to identify miR-153's genomic organisation. To analyse the co-regulation of miR-153 and IA-2β, quantitative PCR analysis of miR-153 and Ia-2β (also known as Ptprn2) was performed after a glucose stimulation assay in MIN6B cells and isolated murine pancreatic islets, and also in wild-type Ia-2 (also known as Ptprn), Ia-2β single knockout and Ia-2/Ia-2β double knockout mouse brain and pancreatic islets. Bioinformatics identification of miR-153 target genes and validation via luciferase reporter assays, western blotting and quantitative PCR were also carried out.
  
  
  RESULTS
  Two copies of miR-153, miR-153-1 and miR-153-2, are localised in intron 19 of Ia-2 and Ia-2β, respectively. In rodents, only miR-153-2 is conserved. We demonstrated that expression of miR-153-2 and Ia-2β in rodents is partially co-regulated as demonstrated by a strong reduction of miR-153 expression levels in Ia-2β knockout and Ia-2/Ia-2β double knockout mice. miR-153 levels were unaffected in Ia-2 knockout mice. In addition, glucose stimulation, which increases Ia-2 and Ia-2β expression, also significantly increased expression of miR-153. Several predicted targets of miR-153 were reduced after glucose stimulation in vitro, correlating with the increase in miR-153 levels.
  
  
  CONCLUSIONS
  This study suggests the involvement of miR-153, IA-2β and miR-153 target genes in a regulatory network, which is potentially relevant to insulin and neurotransmitter release.
authors.affiliation: VIB Center for the Biology of Disease, Gasthuisberg O&N4, Herestraat 49-bus 602, 3000, Leuven, Belgium.
authors.forename: W
authors.initials: W
authors.lastname: Mandemakers
authors.forename: L
authors.initials: L
authors.lastname: Abuhatzira
authors.forename: H
authors.initials: H
authors.lastname: Xu
authors.forename: L A
authors.initials: LA
authors.lastname: Caromile
authors.forename: S S
authors.initials: SS
authors.lastname: Hébert
authors.forename: A
authors.initials: A
authors.lastname: Snellinx
authors.forename: V A
authors.initials: VA
authors.lastname: Morais
authors.forename: S
authors.initials: S
authors.lastname: Matta
authors.forename: T
authors.initials: T
authors.lastname: Cai
authors.forename: A L
authors.initials: AL
authors.lastname: Notkins
authors.forename: B
authors.initials: B
authors.lastname: De Strooper
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism*; D045744:Cell Line, Tumor; D005260:Female; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D035683:MicroRNAs / Q000235:genetics*; D010179:Pancreas / Q000378:metabolism*; D054635:Receptor-Like Protein Tyrosine Phosphatases, Class 8 / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: C577878:MIRN153 microRNA, mouse; D035683:MicroRNAs; C516863:Ptprn protein, mouse; D054635:Receptor-Like Protein Tyrosine Phosphatases, Class 8