Fig. 2.

Effect of dynasore and sucrose on HCA₃ and GPR84 cAMP inhibitory and ERK signaling. a Scheme summarizing all inhibitors and their targets used in the present study. b, c CHO-K1 cells were transiently transfected with HCA₃ or GPR84. b 80 μM dynasore reduced cAMP inhibitory signaling of HCA₃ upon 3HO and 3HDec and of GPR84 upon C10 but not 3HDec stimulation. Sucrose (0.4 M) significantly inhibited only the 3HDec-induced HCA₃-mediated reduction of intracellular cAMP levels. cAMP level of HCA₃- or GPR84-transfected cells in absence of agonist is set to 100%, respectively. c The agonist-induced phosphorylation of ERK1/2 was measured in absence and presence of dynasore or sucrose. All agonists induced an increase in pERK/total ERK levels upon stimulation of HCA₃ and GPR84, respectively. Dynasore blocked the signal of 100 μM 3HO and 100 μM 3HDec completely and sucrose partially in HCA₃–transfected cells. Dynasore did not fully block the signal of 100 μM C10 and 100 μM 3HDec in GPR84-transfected cells. The residual ERK signals of GPR84 in presence of 3HDec and dynasore or sucrose did not differ. pERK/total ERK of HCA₃- or GPR84-transfected cells in absence of agonist is set 1. b, c Data is given as mean ± SEM of at least three independent experiments each carried out in triplicates. * P ≤ 0.05; ** P ≤ 0.01