FIGURE 8.

TRPC5 activity is reduced in HM1-C5 cells transfected with SESTD1 siRNA. Ratiometric measurements of [Ca²⁺]_i in fura-2-loaded HM1-C5 cells transfected with 20 nm SESTD1 siRNA, nonspecific control siRNA, or liposomes only (Mock). Ca²⁺ release from internal stores was activated in Ca²⁺-free buffer by application of 10 μm carbachol (A) or 100 nm trypsin (B). Carbachol-induced (C) or trypsin-induced (D) TRPC5-mediated Ca²⁺ influx was assessed in standard Ca²⁺-containing buffer (2 mm). Shown are means ± S.E. of three independent experiments (each performed with n = 4–6 wells/experimental condition). Statistical analysis shows a selective reduction of agonist-induced TRPC5-mediated Ca²⁺ influx in SESTD1 siRNA-treated cells after termination of Ca²⁺ release (t = 121 s) as well as at the end of the experiment. (***, p < 0.001; *, p < 0.05 versus unselective siRNA; ***, p < 0.001 versus mock; analysis of variance).