Hsp90 inhibition reduces Pparγ signaling. A: F442A cells stably transfected with luciferase under the control of the AP2 promoter (F442A-Ap2Luc cells) were treated with rosiglitazone, tunicamycin, or thapsigargin at the indicated concentrations for 16 h, followed by lysis and homogeneous assay for luciferase activity. B: Cells were treated and assayed as in A, except that the HSR inducers celastrol and 17-DMAG were used. Error bars represent SD, and * indicates P ≤ 0.05 by Student’s t-test.