Fig. 7.

PGE₂ upregulates renin through EP1 via the CREB pathway. M-1 cells were transiently transfected with scrambled (Scrbl) shRNA, CREB shRNA, or EP1 receptor shRNA, 32 h before PGE₂ treatment. A: CREB shRNA blunted the induction of renin mRNA mediated by PGE₂; EP1 knockdown partially prevented this effect. B: representative Western blot of all groups showing similar effects observed for renin mRNA levels. *P < 0.05 vs. Veh, n = 6. C: semiquantitative qRT-PCR measurements of EP mRNAs (percentage of control) showing the effect of EP1 shRNA and CREB1 shRNA transfections (32 h). Scrambled shRNA was used as control. D: protein abundances of EP1 after transfections (32 h) with EP1 shRNA plasmids showing nearly 77% of reduction. E: protein abundances of CREB1 protein after transfections (32 h) with EP1 shRNA plasmids showing nearly 68% of reduction. *P < 0.05 vs. nontransfected cells, n = 4–6.