Fig. 8.

Quantification of cellular lipid mass in nuclear receptor agonist-treated chondrocytes. IMACs were incubated for 72 h with 1 μM DMSO (vehicle control), PPARδ agonist GW501516, PPARγ agonist Rosiglitazone, LXR agonist GW3965, or RXR agonist SR11237. Lipids were extracted, isolated, and mass was measured spectrophotometrically. Proteins were isolated and quantified using BCA. Measurements are reported relative to mg of cell protein. Absolute mean values for triglycerides, total cholesterol, free cholesterol, and cholesterol esters were 7.4, 27.1, 26.4, and 0.75 μg/mg protein, respectively, for DMSO-treated cells. a Cell triglycerides (μg) are significantly elevated by PPARγ, LXR, and RXR treatment and are significantly decreased by PPARδ agonism. b, c, d Total cholesterol, free cholesterol, and cholesterol ester remain unchanged after nuclear receptor agonist treatment. Values represented are the mean ± SEM of ≥5 independent cell isolations. *p < 0.05