Impact of Adenoviral Transduction With SREBP1c or AMPK on Pancreatic Islet Gene Expression Profile

Analysis With Oligonucleotide Microarrays

  1. Frederique Diraison1,
  2. Efthimios Motakis12,
  3. Laura E. Parton1,
  4. Guy P. Nason2,
  5. Isabelle Leclerc1 and
  6. Guy A. Rutter1
  1. 1Henry Wellcome Signalling Laboratories and Department of Biochemistry, School of Medical Sciences, University of Bristol, Bristol, U.K
  2. 2Department of Mathematics, University of Bristol, Bristol, U.K
  1. Address correspondence and reprint requests to Professor Guy A. Rutter, Henry Wellcome Signalling Laboratories and Department of Biochemistry, School of Medical Sciences, University Walk, University of Bristol, Bristol, BS8 ITD, U.K. E-mail: g.a.rutter{at}bristol.ac.uk

Abstract

Accumulation of triglyceride in islets may contribute to the loss of glucose-stimulated insulin secretion (GSIS) in some forms of type 2 diabetes (Diraison et al., Biochem J 373:769–778, 2004). Here, we use adenoviral vectors and oligonucleotide microarrays to determine the effects of the forced expression of SREBP1c on the gene expression profile of rat islets. Sterol regulatory element binding protein-1c (SREBP1c) overexpression led to highly significant (P < 0.1 with respect to null adenovirus) changes in the expression of 1,238 genes or expressed sequence tags, of which 1,180 (95.3%) were upregulated. By contrast, overexpression of constitutively active AMP-activated protein kinase (AMPK), expected to promote lipolysis, altered the expression of 752 genes, of which 702 (93%) were upregulated. To identify specific targets for SREBP1c or AMPK, we eliminated messages that were 1) affected in the same direction by the expression of either protein, 2) changed by less than twofold, or 3) failed a positive false discovery test; 206 SREBP1c-regulated genes (195; 95% upregulated) and 48 AMPK-regulated genes (33; 69% upregulated) remained. As expected, SREBP1c-induced genes included those involved in cholesterol (6), fatty acid (3), and eicosanoid synthesis. Interestingly, somatostatin receptor (sstr1) expression was increased by SREBP1c, whereas AMPK induced the expression of peptide YY, the early endocrine pancreas marker.

Footnotes

  • This article is based on a presentation at a symposium. The symposium and the publication of this article were made possible by an unrestricted educational grant from Servier.

    • Accepted May 25, 2004.
    • Received March 8, 2004.
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