Taste bud cell renewal is inhibited in MRL/lpr mice.

(A) BrdU (green) and KCNQ1 (red) double immunostaining of circumvallate papillae from MRL/+/+ and MRL/lpr mice injected with BrdU. Tissues were collected 1 and 5 days after BrdU injection (Day 1 and Day 5, respectively). Arrows denote some BrdU-labeled cells inside taste buds. (B and C) Quantitative analyses of BrdU-labeled cells in the circumvallate (CV) epithelium collected 1 day (B) and 5 days (C) after BrdU injection. Left, number of BrdU-positive taste cells per taste bud profile; right, number of BrdU-positive perigemmal cells per square millimeter (mm²) of circumvallate epithelium. (D) Ki67 (green) and KCNQ1 (red) double immunostaining: merged confocal fluorescent images of circumvallate papillae from MRL/+/+ and MRL/lpr mice. (E) Average number of Ki67-labeled cells in the basal region of taste bud profile. Ki67-labeled cells in the basal regions of circumvallate taste buds were counted, and the average numbers of Ki67-labeled cells per taste bud profile are shown for MRL/+/+ and MRL/lpr mice. (F) Total number of BrdU-positive cells (including cells in the perigemmal regions and inside the taste buds) per square millimeter (mm²) of circumvallate epithelium 1 day after BrdU injection. Four mice per group per time point were included in the experiments. Six circumvallate sections from each animal were included in the analyses. Data are means ± SEM. Student's t tests were used for statistical analysis. * p<0.05; ** p<0.01. Scale bars, 20 µm.