Physiol. Genomics 34: 327-337, 2008.
First published June 17, 2008; doi:10.1152/physiolgenomics.90211.2008
1094-8341/08 $8.00
Received 7 April 2008;
accepted in final form 16 June 2008.
Physiological Genomics 34:327-337 (2008)
1094-8341/08 $8.00 © 2008 American Physiological Society
Microarray analyses of SREBP-1a and SREBP-1c target genes identify new regulatory pathways in muscle
Sophie Rome*,
Virginie Lecomte*,
Emmanuelle Meugnier,
Jennifer Rieusset,
Cyrille Debard,
Vanessa Euthine,
Hubert Vidal and
Etienne Lefai
INSERM U870; INRA UMR1235; Régulations Métaboliques, Nutrition, et Diabètes; Université Lyon 1; Faculté de Médecine Lyon-Sud, Oullins; INSA-Lyon, RMND, Villeurbanne; and Hospices Civils de Lyon (Service de Diabétologie et Nutrition, Hôpital Edouard Herriot), Lyon, France
In this study we have identified the target genes of sterol regulatory element binding protein (SREBP)-1a and SREBP-1c in primary cultures of human skeletal muscle cells, using adenoviral vectors expressing the mature nuclear form of human SREBP-1a or SREBP-1c combined with oligonucleotide microarrays. Overexpression of SREBP-1a led to significant changes in the expression of 1,315 genes (655 upregulated and 660 downregulated), whereas overexpression of SREBP-1c modified the mRNA level of 514 genes (310 upregulated and 204 downregulated). Gene ontology analysis indicated that in human muscle cells SREBP-1a and -1c are involved in the regulation of a large number of genes that are at the crossroads of different functional pathways, several of which are not directly connected with cholesterol and lipid metabolism. Six hundred fifty-two of all genes identified to be differentially regulated on SREBP overexpression had a sterol regulatory element (SRE) motif in their promoter sequences. Among these, 429 were specifically regulated by SREBP-1a, 69 by SREBP-1c, and 154 by both 1a and 1c. Because both isoforms recognize the same binding motif, we determined whether some of these functional differences could depend on the environment of the SRE motifs in the promoters. Results from promoter analysis showed that different combinations of transcription factor binding sites around the SRE binding motifs may determine regulatory networks of transcription that could explain the superposition of lipid and cholesterol metabolism with various other pathways involved in adaptive responses to stress like hypoxia and heat shock, or involvement in the immune response.
transcription factor; DNA binding motif; promoter; adenovirus; skeletal muscle; human
Copyright © 2008 by the American Physiological Society.