Differential activation of peroxisome proliferator-activated receptors by eicosanoids.
Peroxisome proliferator-activated receptors (PPARs) are nuclear hormone receptors that regulate gene transcription in response to peroxisome proliferators and fatty acids. PPARs also play an important role in the regulation of adipocyte differentiation. It is unclear, however, what naturally occurring compounds activate each of the PPAR subtypes. To address this issue, a screening assay was established using heterologous fusions of the bacterial tetracycline repressor to several members of the peroxisome proliferator-activated receptor (PPAR) family. This assay was employed to compare the activation of PPAR family members by known PPAR activators including peroxisome proliferators and fatty acids. Interestingly, the activation of PPARs by fatty acids was partially inhibited by the cyclooxygenase inhibitor indomethacin, which prevents prostaglandin synthesis. Indeed, prostaglandins PGA1 and 2, PGD1 and 2, and PGJ2-activated PPARs, while a number of other prostaglandins had no effect. We also screened a variety of hydroxyeicosatetraenoic acids (HETEs) for the ability to activate PPARs. 8(S)-HETE, but not other (S)-HETEs, was a strong activator of PPAR alpha. Remarkably, PPAR activation by 8(S)-HETE was stereoselective. In addition, 8(S)-HETE was able to induce differentiation of 3T3-L1 preadipocytes. These results indicate that PPARs are differentially activated by naturally occurring eicosanoids and related molecules.
Yu
K
K
Oncology Research Program, Sandoz Research Institute, Sandoz Pharmaceuticals Corporation, East Hanover, New Jersey 07936, USA.
Bayona
W
W
Kallen
C B
CB
Harding
H P
HP
Ravera
C P
CP
McMahon
G
G
Brown
M
M
Lazar
M A
MA
D016475:3T3 Cells; D017667:Adipocytes / Q000166:cytology / Q000187:drug effects; D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D017931:DNA Primers; D015777:Eicosanoids / Q000494:pharmacology*; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000494:pharmacology; D007213:Indomethacin / Q000494:pharmacology; D007700:Kinetics; D008156:Luciferases / Q000096:biosynthesis; D051379:Mice; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011453:Prostaglandins / Q000494:pharmacology*; D018160:Receptors, Cytoplasmic and Nuclear / Q000096:biosynthesis / Q000187:drug effects / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000378:metabolism; D013329:Structure-Activity Relationship; D014157:Transcription Factors / Q000096:biosynthesis / Q000187:drug effects / Q000378:metabolism*; D015533:Transcriptional Activation; D014162:Transfection
D016861:Cyclooxygenase Inhibitors; D017931:DNA Primers; D015777:Eicosanoids; D006893:Hydroxyeicosatetraenoic Acids; D011453:Prostaglandins; D018160:Receptors, Cytoplasmic and Nuclear; D011994:Recombinant Proteins; D014157:Transcription Factors; C047628:8-hydroxyeicosatetraenoic acid; D008156:Luciferases; D007213:Indomethacin