Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2008-4-22
pubmed:abstractText
Sterol regulatory element binding protein 1c (SREBP1c) is a master regulator of lipogenic gene expression in liver and adipose tissue, where its expression is regulated by a heterodimer of nuclear receptor-type transcription factors retinoid X receptor-alpha (RXRalpha) and liver X receptor-alpha (LXRalpha). Despite the potential importance of SREBP1c in skeletal muscle, little is known about the regulation of SREBP1c in that setting. Here we report that gene expression of RXRgamma is markedly decreased by fasting and is restored by refeeding in mouse skeletal muscle, in parallel with changes in gene expression of SREBP1c. RXRgamma or RXRalpha, together with LXRalpha, activate the SREBP1c promoter in vitro. Moreover, transgenic mice overexpressing RXRgamma specifically in skeletal muscle showed increased gene expression of SREBP1c with increased triglyceride content in their skeletal muscles. In contrast, transgenic mice overexpressing the dominant-negative form of RXRgamma showed decreased SREBP1c gene expression. The expression of Forkhead-O1 transcription factor (FOXO1), which can suppress the function of multiple nuclear receptors, is negatively correlated to that of SREBP1c in skeletal muscle during nutritional change. Moreover, transgenic mice overexpressing FOXO1 specifically in skeletal muscle exhibited decreased gene expression of both RXRgamma and SREBP1c. In addition, FOXO1 suppressed RXRalpha/LXRalpha-mediated SREBP1c promoter activity in vitro. These findings provide in vivo and in vitro evidence that RXR/LXR up-regulates SREBP1c gene expression and that FOXO1 antagonizes this effect of RXR/LXR in skeletal muscle.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
149
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2293-305
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:18202130-Animals, pubmed-meshheading:18202130-Base Sequence, pubmed-meshheading:18202130-Cells, Cultured, pubmed-meshheading:18202130-DNA-Binding Proteins, pubmed-meshheading:18202130-Eating, pubmed-meshheading:18202130-Fasting, pubmed-meshheading:18202130-Female, pubmed-meshheading:18202130-Forkhead Transcription Factors, pubmed-meshheading:18202130-Gene Expression Regulation, pubmed-meshheading:18202130-Humans, pubmed-meshheading:18202130-Male, pubmed-meshheading:18202130-Mice, pubmed-meshheading:18202130-Mice, Inbred C57BL, pubmed-meshheading:18202130-Mice, Transgenic, pubmed-meshheading:18202130-Models, Biological, pubmed-meshheading:18202130-Muscle, Skeletal, pubmed-meshheading:18202130-Organ Specificity, pubmed-meshheading:18202130-Orphan Nuclear Receptors, pubmed-meshheading:18202130-Promoter Regions, Genetic, pubmed-meshheading:18202130-Receptors, Cytoplasmic and Nuclear, pubmed-meshheading:18202130-Retinoid X Receptor gamma, pubmed-meshheading:18202130-Sterol Regulatory Element Binding Protein 1
pubmed:year
2008
pubmed:articleTitle
Regulation of SREBP1c gene expression in skeletal muscle: role of retinoid X receptor/liver X receptor and forkhead-O1 transcription factor.
pubmed:affiliation
Department of Molecular Medicine and Metabolism, Medical Research Institute, Tokyo Medical and Dental University, 2-3-10 Kanda-surugadai, Chiyoda-ku, Tokyo 101-0062, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't