FIGURE 2.

Involvement of IL-1β production in PTX-induced enhancement of Ca²⁺ response by Ang II stimulation. A, effects of PTX on the expression of AT1R, IL-1α, and IL-1β mRNAs. After cells were treated with PTX (100 ng/ml) for 24 h, total RNA was extracted. The expression of mRNAs was determined with microarray analysis. ID numbers of primer probe sets are shown in parenthesis. B, effects of respective reagents on IL-1β mRNA expression in cardiac fibroblasts. Cells were treated with PTX (100 ng/ml) for 24 h, treated with mastoparan-7 (10 μm) for 12 h, or infected with LacZ, WT Gα_i, Gα_i-ct, RGS4, and GRK2-ct at 300 MOI for 48 h. The -fold increases were calculated by the values of untreated cells (none) set as 1. C, effects of B-oligomer of PTX on Ang II-induced Ca²⁺ releases. Cells were treated with B-oligomer (1 or 10 nm) for 24 h before Ca²⁺ measurement. D, time course of PTX-induced expression of IL-1β protein. E, effects of IL-1β siRNAs, DN-Rac, and wortmannin (WTM) on PTX-induced IL-1β production. Two different siRNAs were used. F and G, effects of IL-1β neutral antibody (F) or IL-1β siRNAs (G) on Ang II-induced Ca²⁺ responses in control, PTX-treated, or IL-1β-treated cells. Cells were treated with PTX (100 ng/ml) or IL-1β (1 ng/ml) for 24 h before Ang II (100 pm) stimulation with or without anti-IL-1β antibody (500 μg/ml). Cells were transfected with IL-1β siRNAs (100 nm) 48 h before PTX treatment. *, p < 0.05; **, p < 0.01; ***, p < 0.001 versus PTX-untreated, B-oligomer-untreated, control siRNA-treated, PTX-treated, or IL-1β-treated cells. Error bars, S.E.