Figure 6

Efficacy of ARBs at preventing StAR upregulation in SII-stimulated H295R cells.

(A,B) Western blotting for StAR protein levels in H295R cells transfected to overexpress βarr1 and treated for 6 hrs with 10 μM SII alone (SII) or in the presence of 10 μM of each of the sartans tested. Representative blots of 3 independent experiments are shown in (A), including blots for βarr1 to confirm its overexpression and for GAPDH (glyceraldehyde 3-phosphate dehydrogenase) as loading control and the StAR protein induction (as % of the SII response), as derived by densitometric quantification, is shown in (B). *, p < 0.05, n = 3 independent experiments/treatment. Blots shown have been cropped to fit space requirements and run under the same experimental conditions (same gel) (the full length blots are shown in Supplementary Information). (C,D) Western blotting for StAR protein levels in dominant negative βarr1 mutant-transfected H295R cells and treated as in (A–B). Representative blots are shown in (C), including blots for the dominant negative βarr1 mutant to confirm its overexpression and for GAPDH as loading control and the StAR protein induction (as % of vehicle-no stimulation), as derived by densitometric quantification, is shown in (D). No significant differences were observed among treatments, nor did any treatment cause any induction in StAR levels. Blots shown have been cropped to fit space requirements and run under the same experimental conditions (same gel) (the full length blots are shown in Supplementary Information). n = 3 independent experiments/treatment. LOS: Losartan-; VAL: Valsartan; CAN: Candesartan; OLM: Olmesartan; IRB: Irbesartan.