Quantitative differential expression analysis reveals miR-7 as major islet microRNA

Biochem Biophys Res Commun. 2008 Feb 22;366(4):922-6. doi: 10.1016/j.bbrc.2007.12.052. Epub 2007 Dec 18.


MicroRNAs (miRNAs) are non-coding gene products that regulate gene expression through specific binding to target mRNAs. Cell-specific patterns of miRNAs are associated with the acquisition and maintenance of a given phenotype, such as endocrine pancreas (islets). We hypothesized that a subset of miRNAs could be differentially expressed in the islets. Using miRNA microarray technology and quantitative RT-PCR we identified a subset of miRNAs that are the most differentially expressed islet miRNAs (ratio islet/acinar>150-fold), miR-7 being the most abundant. A similarly high ratio for miR-7 was observed in human islets. The ratio islet/acinar for miR-375, a previously described islet miRNA, was <10 and is 2.5x more abundant in the islets than miR-7. Therefore, we conclude that miR-7 is the most abundant endocrine miRNA in islets while miR-375 is the most abundant intra-islet miRNA. Our results may offer new insights into regulatory pathways of islet gene expression.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Gene Expression Profiling*
  • Gene Expression Regulation
  • Humans
  • Islets of Langerhans / cytology
  • Islets of Langerhans / metabolism*
  • MicroRNAs / genetics*
  • Oligonucleotide Array Sequence Analysis
  • Rats
  • Rats, Inbred Lew
  • Reverse Transcriptase Polymerase Chain Reaction


  • MIRN375 microRNA, rat
  • MicroRNAs