Figure 3.

Norepinephrine contributes to cellular senescence and upregulates profibrogenic and proinflammatory cytokines in renal tubular cells. (A, B) Representative Western blot of p21, γ-H2AX or FN, Col 1 in TKPTS cells cultured with PBS (control) or different concentrations of NE (0.1 nM, 1 nM, 10 nM, 100 nM, 1 μM, 10 μM, and 100 μM) (n=3 in each group). (C, D) Representative Western blot of γ-H2AX or FN, Col 1 in TKPTS cells incubated with PBS (control) or NE at a final concentration of 10 nM for the indicated periods (1, 6, 12, 24, 48, and 72 hours) (n=3 in each group). (E–G) TKPTS cells were incubated with NE (10 nM) or H₂O₂ (100 μM) for 48 hours and were then harvested. (E) Representative Western blot of p53, p21, and γ-H2AX in TKPTS cells treated with PBS, NE, or H₂O₂ with densitometry analysis (n=3–5 in each group). (F) Representative images of cell morphology and SA-β-gal staining of TKPTS cells treated with PBS, NE, or H₂O₂ using a microscope (n=3 in each group). Scale bar=50 μm. (G) mRNA levels of senescence-related proteins (p53, p21, p16, HMGA2, H2AX), SASP components (IL-6, IL-8, IL-1β), and profibrotic cytokines (TGF-β1, CTGF) in each group were detected by qRT-PCR analysis (n=3–7 in each group). *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001. Bars represented means ± SEM.