Figure A1.

(A) CD45/BrdU gating by flow cytometry. The percentage of CD45⁺ cells in the LGs was significantly higher in 1Y-old mice than in 8W-old mice (p = 0.044; one-way ANOVA followed by Tukey’s post hoc test; n = 9, 5, and 3 for 8W-, 1Y-, and 2Y-old mice, respectively). The percentage of CD45⁺ cells in the LGs was also significantly higher than that in the MGs, irrespective of age (p = 0.019 in 8W-old mice and 0.0005 in 1Y-old mice, respectively; paired t-test; n = 5 per group). The percentage of CD45⁻ BrdU⁺ cells in the MGs was not different between 8W- and 1Y-old mice (p = 0.483); however, the percentage of CD45⁻ BrdU⁺ cells in the LGs was significantly higher in 1Y-old mice than in 8W-old mice (p < 0.0001; independent t-test; n = 5 per group). (B) Representative images of the LG sections by Ki-67 immunofluorescence staining (400×). Arrows indicate inflammatory foci. The expression of Ki67⁺ cells in both the acinar and inflammatory cell infiltrating areas tends to increase with aging. * p < 0.05, *** p < 0.001, and **** p < 0.0001. Data are presented as means ± standard error.