In vitro activity: GSK0660 is a potent antagonist of PPARβ and PPARδ, with IC50s of both 155 nM, and is nearly inactive on PPARα and PPARγ with IC50s of both>10 μM.GSK0660 (100 nM) reduces CPT1a (a PPARβ/δ target gene) expression below the basal vehicle-treated level by approximately 50%, but shows no effect on PDK4 expression, which is also a PPARβ/δ target gene in skeletal muscle cells.GSK0660 (1 μM) markedly blocks GW501516-mediated attenuation of glutamate release, and the effect of GW501516 on ROS generation in BV-2 cells stimulated with LPS.GSK0660 (0.5 μM) reduces the levels of AMPK and eNOS phosphorylation, and BMP-2, Runx-2 mRNA expression in MC3T3-E1 cells.

Kinase Assay: GSK0660 is a potent antagonist of PPARβ and PPARδ, with IC50s of both 155 nM, and is nearly inactive on PPARα and PPARγ with IC50s of both>10 μM. GSK0660 antagonizes 100% of the activity of PPARβ/δ with a pIC50 of 6.8. GSK0660 (100 nM) reduces CPT1a (a PPARβ/δ target gene) expression below the basal vehicle-treated level by approximately 50%, but shows no effect on PDK4 expression, which is also a PPARβ/δ target gene in skeletal muscle cells.

Cell Assay: GSK0660 is dissolved in DMSO.Cell viability is determined by the MTT dye. MC3T3-E1 cells are incubated with bezafibrate (1–1000 μM) for 24, 48, or 72 h, and are pretreated with the AMPK inhibitor compound C (5 μM), PPARβ inhibitor GSK0660 (0.5 μM), PPARα inhibitor MK886 (10 μM), or NOS inhibitor L-NAME (1000 μM) followed by bezafibrate (100 μM) incubation for 48 h. After the incubations, 10 μL of MTT is added to each well of a 96-well microplate, and the microplates are placed in an incubator at 37°C for 4 h.