PT  - JOURNAL ARTICLE
AU  - Priyadarshini Raman
AU  - Barbara L. F. Kaplan
AU  - Norbert E. Kaminski
TI  - 15-Deoxy-Δ<sup>12,14</sup>-Prostaglandin J<sub>2</sub>-Glycerol, a Putative Metabolite of 2-Arachidonyl Glycerol and a Peroxisome Proliferator-Activated Receptor γ Ligand, Modulates Nuclear Factor of Activated T Cells
AID  - 10.1124/jpet.112.193003
DP  - 2012 Sep 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 816--826
VI  - 342
IP  - 3
4099  - http://jpet.aspetjournals.org/content/342/3/816.short
4100  - http://jpet.aspetjournals.org/content/342/3/816.full
SO  - J Pharmacol Exp Ther2012 Sep 01; 342
AB  - 2-Arachidonyl glycerol (2-AG) is an endogenous arachidonic acid derivative released on demand from membrane precursors. 2-AG-mediated suppression of interleukin (IL)-2 depends on cyclooxygenase 2 (COX-2) metabolism and peroxisome proliferator-activated receptor γ (PPARγ) activation. 15-Deoxy-Δ12,14-prostaglandin J2-glycerol ester (15d-PGJ2-G), a putative COX-2 metabolite of 2-AG, acts as a PPARγ ligand and produces IL-2 suppression in activated Jurkat T cells, in part, by decreasing nuclear factor of activated T cells (NFAT) transcriptional activity. The objective of the present studies was to investigate the mechanism by which 15d-PGJ2-G modulates NFAT activity to suppress IL-2. 15d-PGJ2-G treatment decreased phorbol 12-myristate 13-acetate (PMA)/calcium ionophore (Io)-induced NFAT DNA binding to the human IL-2 promoter and nuclear NFAT2 accumulation. It is noteworthy that 15d-PGJ2-G treatment increased active nuclear HDM2 (human homolog of the oncoprotein and E3 ubiquitin ligase murine double minute 2) expression, whereas there was no change in the expression of glycogen synthase kinase 3β, both of which regulate NFAT. 15d-PGJ2-G and other PPARγ agonists, such as rosiglitazone and ciglitazone, decreased PMA/Io-mediated elevation in intracellular calcium concentration ([Ca2+]i) in activated Jurkat cells. We were surprised to find that the PPARγ antagonists 2-chloro-5-nitro-N-4-pyridinylbenzamide (T0070907) and 2-chloro-5-nitrobenzanilide (GW9662) also decreased the PMA/Io-mediated elevation in [Ca2+]i in activated T cells. In addition, the presence of T0070907 plus 15d-PGJ2-G produced an additive decrease in PMA/Io-mediated elevation of [Ca2+]i, suggesting that the 15d-PGJ2-G effects on calcium might be either PPARγ-independent or -dependent on occupation of the PPARγ ligand binding domain. Collectively, our findings suggest that 15d-PGJ2-G increases active nuclear HDM2, which could lead to a decrease in NFAT2 and IL-2 suppression.