Figure 3.

The anti-aging effects of calcitriol on NK cells. (a) The expression of the vitamin D receptor (VDR), sirtuin 1 (SIRT1), SIRT1-∆Exon8, and protein kinase R-like endoplasmic reticulum kinase (pERK) in NK cells was detected by western blotting analysis after treatment with calcitriol for 48 h. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was used as the loading control. Bar diagram illustrating the western blotting results (n = 3). *P < 0.05 and **P < 0.01 were compared with NC (n = 3). (b) Dosage mortality curve of NK cells after treatment with hydrogen peroxide (H₂O₂) for 24 h. (c) Percentage of TIM3 cells exhibiting high expression after treatment with 100 μM H₂O₂ for 24 h. (d) The senescence-associated β-galactosidase staining and analysis results. The senescent cells were stained in blue and indicated by red arrows. Scale bar, 50 μm. (e) NK cells were stained with Hoechst and Chloromethyl-X-Rosamine (CMXRos) to determine the cell location and mitochondrial membrane potential. The aging and apoptotic cells were Hoechst⁺ CMXRos⁻ and indicated by white arrows. Scale bar, 50 μm. Statistical analysis showed relative fluorescence intensity. *P < 0.05 and **P < 0.01 were compared with H₂O₂ group in figures C, D, and E (n = 3)