Abstract
Peroxisome proliferator-activated receptor (PPARs) modulate target gene expression in response to unsaturated fatty acid ligands, such as arachidonic acid (AA). Here, we report that the AA metabolite 15-hydroxyeicosatetraenoic acid (15-HETE) activates the ligand-dependent activation domain (AF2) of PPARβ/δ in vivo, competes with synthetic agonists in a PPARβ/δ ligand binding assay in vitro, and triggers the interaction of PPARβ/δ with coactivator peptides. These agonistic effects were also seen with PPARα and PPARγ, but to a significantly weaker extent. We further show that 15-HETE strongly induces the expression of the bona fide PPAR target gene Angptl4 in a PPARβ/δ-dependent manner and, conversely, that inhibition of 15-HETE synthesis reduces PPARβ/δ transcriptional activity. Consistent with its function as an agonistic ligand, 15-HETE triggers profound changes in chromatin-associated PPARβ/δ complexes in vivo, including the recruitment of the coactivator cAMP response element-binding protein binding protein. Both 15R-HETE and 15S-HETE are similarly potent at inducing PPARβ/δ coactivator binding and transcriptional activation, indicating that 15-HETE enantiomers generated by different pathways function as PPARβ/δ agonists.
Footnotes
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This work was supported by the Deutsche Forschungsgemeinschaft [Grants SFB-TR17/A3, Se263/17-1] and the Landes-Offensive zur Entwicklung wissenschaftlich-ökonomischer Exzellenz-Schwerpunkt “Tumor and Inflammation” of the state of Hesse.
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Article, publication date, and citation information can be found at http://molpharm.aspetjournals.org.
doi:10.1124/mol.109.060541.
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ABBREVIATIONS:
- PPAR
- peroxisome proliferator-activated receptor
- RXR
- retinoid X receptor
- PPRE
- peroxisome proliferator responsive element
- CBP
- cAMP response element-binding protein binding protein
- GW501516
- 2-[2-methyl-4-([4-methyl-2-[4-(trifluoromethyl)phenyl)-1,3-thiazol-5-yl]methylsulfanyl]phenoxy]acetic acid
- L165,041
- [4-[3-(4-acetyl-3-hydroxy-2-propylphenoxy)propoxy]phenoxy]acetic acid
- AA
- arachidonic acid
- LBD
- ligand binding domain
- PG
- prostaglandin
- 15R-HETE
- 15(R)-hydroxy-5Z,8Z,11Z,13E-eicosatetraenoic acid
- 15S-HETE
- 15(S)-hydroxy-5Z,8Z,11Z,13E-eicosatetraenoic acid
- HPETE
- hydroperoxyeicosatetraenoic acid
- COX
- cyclo-oxygenase
- LOX
- lipoxygenase
- NDGA
- nordihydroguaiaretic acid
- EDBCA
- ethyl-3,4-dihydroxy-benzylidene-cyanoacetate
- GW1929
- N-(2-benzoylphenyl)-O-[2-(methyl-2-pyridinylamino)ethyl]-l-tyrosine hydrochloride
- LX
- lipoxin
- GW7647
- 2-[[4-[2-[[(cyclohexylamino)carbonyl](4-cyclohexylbutyl)amino]ethyl]phenyl]thio]-2-methylpropanoic acid
- CHO
- Chinese hamster ovary
- DMEM
- Dulbecco's modified Eagle's medium
- FCS
- fetal calf serum
- PCR
- polymerase chain reaction
- qPCR
- quantitative polymerase chain reaction
- siRNA
- small interfering RNA
- PIPES
- piperazine-N,N′-bis(2-ethanesulfonic acid)
- NP40
- nonidet P40
- TR-FRET
- time-resolved fluorescence resonance energy transfer
- LC
- liquid chromatography
- TATAi
- TATA initiator module
- PGC1α
- peroxisome proliferator-activated receptor γ coactivator 1α
- Angptl4
- angiopoietin-like 4
- Cre
- cyclization recombination.
- Received August 27, 2009.
- Accepted November 10, 2009.
- Copyright © 2010 The American Society for Pharmacology and Experimental Therapeutics
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