Abstract
Purpose :
Retinitis Pigmentosa is a genetic disease that causes progressive photoreceptor death and blindness. Physical exercise has shown to be neuroprotective via elevating circulating factors, including adiponectin. We hypothesized that physical exercise would protect against loss of photoreceptors in retinitis pigmentosa.
Methods :
Breeding pairs of rd10 and wild type mice with C57BL/6J background at 6-weeks of age were housed for mating, and pregnancy was confirmed by the presence of seminal plugs. Subsequently, free-spinning (exercise) or locked (sedentary) running dishes were introduced into their cages for voluntary running until the birth of their offspring. At 6-weeks of age, the offspring were sacrificed and retinal cross-sections were prepared to examine the change of photoreceptor nuclei density and rod outer segment length by immunostaining. Two-way ANOVA with post-hoc Tukey’s test were used for statistical analysis and the data were expressed as mean ± standard error of the mean.
Results :
The sedentary rd10 group had significantly fewer photoreceptor nuclei (67 ± 12) and shorter rods outer segment (1.8 ± 0.1 µm) compared to sedentary wildtype mice (490 ± 2 photoreceptor nuclei and 21.2 ± 0.8 µm rods outer segment) (p < 0.001). However, rd10 mice that exercised showed a significant increase in the number of photoreceptor nuclei (144 ± 17) and length of rods outer segment (9.4 ± 0.2 µm) compared to their sedentary counterparts (p < 0.001). Despite these improvements, the rd10 exercise group still had significantly fewer photoreceptor nuclei and shorter rods outer segment compared to the wildtype exercise group (493 ± 1 photoreceptor nuclei and 22.6 ± 0.1 µm rods outer segment) (p < 0.001). Exercise did not significantly affect the wildtype mice.
Conclusions :
Physical exercise partially prevented the loss of photoreceptors in adult rd10 mice. Physical exercise could be a non-invasive and early intervention for preventing/delaying photoreceptor degeneration in retinitis pigmentosa.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.