Article Figures & Data
Figures
- Figure 1
Exercise (3-4 weeks) produces a small increase in hippocampal progranulin in young adult wild-type mice. Two- to 3-month-old wild-type mice were randomized to sedentary or exercise groups for three to four weeks (A). B, Exercise produced a robust increase in BDNF (****p < 0.0001). C, Representative BDNF and α-tubulin blots. D, Exercise did not significantly increase frontal cortex progranulin protein. E, Exercise produced a small but statistically significant increase in hippocampal progranulin (*p = 0.038). F, Exercise did not affect plasma progranulin. n = 8–16 mice per group. Values in B–F are expressed relative to the sedentary group.
- Figure 2
Progranulin deficiency does not affect wheel-running behavior. Mice aged 6 months were randomized to sedentary or exercise groups for 7.5 weeks. A, No genotype differences were detected in wheel running distance between Grn+/+ , Grn+/− , and Grn−/− mice. B, Exercise reduced body weight similarly in all three genotypes (***ANOVA exercise effect, p = 0.003). n = 10–15 mice per group.
- Figure 3
Exercise (7.5 weeks) does not increase progranulin in wild-type or Grn+/− mice. Exercise for 7.5 weeks did not increase progranulin mRNA in frontal cortex (A) or thalamus (B), or progranulin protein levels in the hippocampus (C) or plasma (D). E–G, In contrast, exercise increased hippocampal BDNF levels across all three genotypes (E, ANOVA effect of exercise, p = 0.035), with no change in α-tubulin as a loading control (F). G, Representative BDNF and α-tubulin blots. H, Exercise also increased the number of doublecortin (DCX)-positive neurons in the dentate gyrus (ANOVA effect of exercise p < 0.0001, Sidak’s post hoc test exercise > sedentary Grn+/+ , p = 0.0089, Grn+/− , p = 0.0198). Representative images (20×) are shown of doublecortin immunostaining in the dentate gyrus. Scale bar, 25 µm. Mice were 6-months-old on average when beginning the study, and 8-months-old on average when samples were collected. n = 10–15 mice per group. Values in A–F are expressed relative to the wild-type sedentary group.
- Figure 4
Exercise (4 weeks) does not increase progranulin protein levels in multiple brain regions of Grn+/− mice. Four- to 8-month-old Grn+/− mice were randomized to sedentary or exercise groups for 4 weeks (A). Exercise did not increase progranulin protein levels in frontal cortex (B), thalamus (C), or hippocampus (D), despite producing the expected increase in the number of doublecortin-positive neurons in the dentate gyrus (E, ** p < 0.01). Values in B–D are expressed relative to sedentary Grn+/+ mice, with sedentary Grn+/− mice set at 0.5 to maintain a consistent scale with Figure 3. n = 11–12 per group.
- Figure 5
Group housing does not potentiate the effects of exercise on progranulin. Six weeks of wheel running (A) failed to increase frontal cortex progranulin mRNA (B) or hippocampal progranulin protein (C) in either solo- or group-housed wild-type mice aged 3–6 months. D-F, Hippocampal BDNF was increased by exercise (D; ANOVA effect of exercise, p = 0.041). F, Representative BDNF and α-tubulin blots for each group. n = 8–14 mice per group. Values in B–E are expressed relative to the solo-housed sedentary group.
- Figure 6
Exercise (7.5 weeks) reduces cortical microgliosis in Grn−/− mice. A, Grn−/− mice had elevated CD68 immunoreactivity in the frontal cortex, hippocampus, and thalamus (ANOVA genotype effect, p < 0.0001). Global analysis of CD68 immunostaining revealed a region x genotype interaction (p < 0.0001), so each region was analyzed with a separate ANOVA. Analysis of CD68 immunostaining in the frontal cortex revealed an effect of genotype (ANOVA, p < 0.0001) and a strong trend for an exercise effect (ANOVA exercise effect, p = 0.051). Subsequent post hoc analysis revealed significantly lower CD68 immunoreactivity in exercised relative to sedentary Grn−/− mice (*p < 0.05). B, Representative images (20×) of CD68 immunostaining from the frontal cortex. Scale bar, 25 µm.
Tables
Row Figure Panel Description Test Power for 30% change 70% power to detect change of: 80% power to detect change of: Measures of progranulin levels a 1 D Frontal cortex progranulin Student's t test 0.93 22% 24% b 1 E Hippocampus progranulin Student's t test 0.98 18% 21% c 1 F Plasma progranulin Student's t test 0.82 26% 29% d 3 A Frontal cortex progranulin mRNA Two-way ANOVA, Sidak's post hoc test 1 5% 6% e 3 B Thalamus progranulin mRNA Two-way ANOVA, Sidak's post hoc test 1 8% 9% f 3 C Hippocampus progranulin Two-way ANOVA, Sidak's post hoc test 1 11% 12% g 3 D Plasma progranulin Two-way ANOVA, Sidak's post hoc test 1 15% 17% h 4 B Frontal Cortex progranulin Student's t test 1 15% 17% i 4 C Thalamus progranulin Student's t test 1 8% 9% j 4 D Hippocampus progranulin Student's t test 1 14% 16% k 5 B Frontal Cortex progranulin Two-way ANOVA, Sidak's post hoc test 0.35 47% 54% l 5 C Hippocampus progranulin Two-way ANOVA, Sidak's post hoc test 0.52 37% 42% Exercise-related positive controls m 1 B Hippocampus BDNF Student's t test 0.57 35% 39% n 1 B Hippocampus α-tubulin Student's t test 1 9% 10% o 2 A Running distance Two-way Repeated Measures ANOVA 0.50 2092 m (38% change) 2360 m
(43% change)p 2 B Body weight Two-way ANOVA, Sidak's post hoc test 0.97 6.5 g (22% change) 7.3 g (25% change) q 3 E Hippocampus BDNF Two-way ANOVA, Sidak's post hoc test 0.56 35% 40% r 3 F Hippocampus α-tubulin Two-way ANOVA, Sidak's post hoc test 0.84 25% 29% s 3 G Dentate gyrus doublecortin-positive neurons Two-way ANOVA, Sidak's post hoc test 0.38 8.3 cells
(45% change)9.4 cells
(51% change)t 4 E Dentate gyrus doublecortin-positive neurons Student's t test 0.10 33.9 cells
(113% increase)38.3 cells
(127% increase)u 4 D Hippocampus BDNF Two-way ANOVA, Sidak's post-hoc test 0.85 25% 28% v 5 E Hippocampus α-tubulin Two-way ANOVA, Sidak's post-hoc test 1 7% 8% Row Figure Panel Description Test Power for 30% effect size Power to normalize pathology Delta at 70% power Delta at 80% power Global CD68 analysis Three-way ANOVA w 6 A Frontal cortex CD68 Two-way ANOVA, Sidak's post hoc test 0.54 1 0.45% area(36% change) 0.51% area(41% change) x 6 A Hippocampus CD68 Two-way ANOVA, 's post hoc test 0.16 0.55 1.40% area (78% change) 1.58% area (88% change) y 6 A Thalamus CD68 Two-way ANOVA, Sidak's post hoc test 0.23 0.94 2.61% area (63% change) 2.95% area (71% change)
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