Figure 4.

Atipamezole (α₂-adrenergic antagonist) reverses cellular senescence induced by NE in renal tubular cells. TKPTS cells were incubated with NE (10 nM) for 48 hours after pretreatment with adrenergic antagonists or PBS for an hour. (A, B) mRNA expressions of ADRA1B, ADRA2A, ADRB1, ADRB2, and ADRB3 in PBS (control) or NE-treated TKPTS cells as shown by qRT-PCR analysis (n=3–8 in each group). (C) Representative Western blotting of p21 and γ-H2AX in TKPTS cells treated with PBS, NE, and NE+ATI (Atipamezole, 100 nM, 1 μM, 10 μM, and 100 μM) with densitometry analysis (n=3 in each group). (D, E) Representative Western blotting of p21 and γ-H2AX in TKPTS cells incubated with PBS, NE, and NE+BUT (Butoxamine)/ICI (ICI118551) (two β₂-adrenergic antagonists, 100 μM, 10 μM, 1 μM, and 100 nM) with densitometry analysis, respectively (n=3 in each group). (F) mRNA expressions of p53, p21, p16, H2AX, IL-6, IL-8, and IL-1β in TKPTS cells cultured with PBS, NE, and NE+ATI (10 μM) as displayed by qRT-PCR analysis (n=3–8 in each group). *P < 0.05, **P < 0.01, ***P < 0.001. Bars represented means ± SEM.