Figure 7.

Expression of PLB or knockdown of β1-AR rescues the effect of HuR-knockdown in aggravating SR Ca²⁺. (A–C) H9C2 cells were transfected with a siHuR for 48 h and further treated with ISO (20 μM) or saline for 15 min. The protein levels of HuR, PLB, β1-AR, and TUBA were analysed by western blot analysis (A). The levels of SR Ca²⁺ were tested (B); the intensity of the fluorescence was shown as the means ± SD from three independent experiments and used to analyse the significance by using Mann–Whitney U test (C) (*P < 0.05). (D, E) H9C2 cells were transfected with a siHuR for 24 h. Cells then were further transfected with a vector expressing PLB (pPLB) (D) or with a β1-AR siRNA (siβ1-AR) (E) and cultured for additional 24 h. After treatment with ISO (20 μM) for 15 min, the protein levels of HuR, PLB, and TUBA were analysed by western blot analysis (upper). The levels of SR Ca²⁺ were tested (middle); the intensity of the fluorescence in (D and C) was shown as the means ± SD from three independent experiments and analysed for significance by Mann–Whitney U test (bottom) (*P < 0.05).