Long-term, age-associated activity quantification in the DE50-MD dog model of Duchenne muscular dystrophy (DMD)

Dis Model Mech. 2025 Jun 4:dmm.052135. doi: 10.1242/dmm.052135. Online ahead of print.

Abstract

Animal models with a clinically relevant phenotype remain important for robust evaluation of novel therapeutics for the fatal, X-linked genetic disorder, Duchenne Muscular Dystrophy (DMD). Demonstration of functional improvement is crucial for both patients and regulatory authorities. Here we investigate non-invasive methods to quantify activity changes in DE50-MD dogs, using collar-based, tri-axial accelerometers. Using Axivity-AX3 accelerometers, we measured activity in affected DE50-MD male dogs (3-8 per age point) and littermate wild-type (WT) male controls (3-13 per age point) at monthly intervals from 3 to 18 months of age. Acceleration vector magnitudes were used to derive a series of activity measures over 24-hours. Mixed model analyses were used to examine differences between affected and WT groups at different ages. DE50-MD dogs' activity indicators were significantly higher for % time spent at rest (p<0.001) and significantly lower for all other activity indicators (all p<0.05), when compared to age-matched WT dogs. Relatively few animals would be required to detect treatment effects with adequate power using these unbiassed, selected and composite activity measures. Our approach reveals opportunities for cross-model standardisation of activity monitoring.

Keywords: Accelerometer; Activity; DE50-MD; DMD; Dog; Sensor; Wearable.