Figure 3.

Involvement of CALHM1 channels in hTBC Ca²⁺ signaling. A) Control (c) and LA-treated hTBC samples were analyzed for activation of upstream and downstream pathway components of the ERK1/2 cascade. Serum–starved (S; 6 h) hTBCs were exposed for 10 min to serum that contained medium. B) Cultured hTBCs (2 × 10⁵ cells/assay) were loaded with Fura-2/AM and changes in [Ca²⁺]_i (F₃₄₀/F₃₈₀) were monitored in response to 20 µM LA. hTBC, preincubated (30 min) with: RR (20 µM) or 2-APB (30 µM), were exposed to 20 µM LA. Experiments were performed in Ca²⁺-containing medium. C) Changes in [Ca²⁺]_i in mock- or Calhm1 siRNA-transfected hTBCs exposed to 20 µM LA. CALHM1 levels in mock- or Calhm1 siRNA-transfected hTBCs (inset). Actin served as loading control. Data are means ± sem (n = 7) conducted in triplicate. Data are representative of 3–5 independent experiments.