Fig. 2.
PP5C is required for the FKBP51-mediated inhibition of Isoc in PAECs. (a) Genetic suppression of PP5C expression was achieved by 48 h siRNA transfection of PAECs. As analyzed by western blot and (b) densitometry (calculated as band intensity of the indicated protein relative to that of β-actin and normalized to one for control PAECs), dexamethasone (Dex; 10 nM) treatment resulted in the overexpression of FKBP51 in PAECs transfected with PP5C siRNA or a scrambled control. *P < 0.05 vs. no Dex treatment; n = 3. (c) Isoc in Dex (10 nM)-treated PAECs (red) was significantly decreased from control PAECs (gray). PP5C siRNA in PAECs expressing endogenous FKBP51 (vehicle control) did not change Isoc, but in PAECs expressing increased FKBP51, genetic supression of PP5C prevented inhibition of Isoc (*P < 0.05; n = 6). (d) PP5C siRNA treatment decreases PP5C expression in constitutive FKBP51 overexpressing PAECs (cFKBP51) as shown by western blot analysis and (e) densitometry (calculated as band intensity of the indicated protein relative to that of β-actin and normalized to one for control cFKBP51 PAECs. *P < 0.05 vs. scrambled siRNA; n = 3). (f) cFKBP51 cells treated with scrambled siRNA (red) demonstrated reduced Isoc relative to control PAECs (gray) (*P < 0.05; n = 5). FKBP51 overexpressing PAECS treated with PP5C siRNA (blue) resulted in significantly increased Isoc compared to scrambled control (red) (^P < 0.05; n = 5). cFKBP51 cells treated with PP5C siRNA (blue) do not have a significantly different Isoc than control PAECs (gray). Data for control PAECs (gray) are those shown in (c) and are included here for comparison.