Riddell Dominique, Harron Rachel, Hildyard John, Wells Dominic, Piercy Richard
Comparative Neuromuscular Diseases Laboratory, Clinical Sciences and Services, Royal College Street, London, NW1 0TU, UK.
Comparative Biomedical Sciences, The Royal Veterinary College, Royal College Street, London, NW1 0TU, UK.
Wellcome Open Res. 2025 Mar 17;9:681. doi: 10.12688/wellcomeopenres.23269.2. eCollection 2024.
Duchenne muscular dystrophy (DMD) is a fatal muscle wasting disease caused by mutations in the dystrophin gene resulting in cycles of muscle degeneration, inflammation and regeneration. The 6-minute walk test (6MWT) is a key functional outcome measure for DMD patient clinical trials and has been adapted for use in animal models of the disease. The DE50-MD dog model of DMD closely reflects the DMD patient phenotype prior to loss of ambulation. For pre-clinical trials using this model, functional outcome measures must be established.
This longitudinal study compared distance walked in a 6MWT by DE50-MD and WT control dogs and assessed the utility of the 6MWT as a functional biomarker. Dogs underwent two 6MWTs conducted approximately 48-hours apart, at 3, 6, 9, 12, 15 and 18 months of age. In addition, we evaluated the stability of selected blood-borne biomarkers in 12-month old DE50-MD and WT dogs 0, 3, 6, 24 and 48 hours following a 6MWT.
DE50-MD dogs exhibited significantly shorter 6-minute walk distance (6MWD) than WT dogs at all timepoints (P<0.05), with no difference in 6MWD between the first and second 6MWT. C-C motif chemokine ligand 2 (CCL2), myomesin-3 (MYOM3) and myostatin (MSTN) were biomarkers of the DE50-MD phenotype that remained unchanged in DE50-MD dogs following the 6MWT, while creatine kinase (CK) activity significantly increased 3-hours following the test in DE50-MD dogs but remained unchanged in WT dogs.
The 6MWT effectively discriminates DE50-MD from WT dogs aged 3-18 months and a single 6MWT is sufficient for future studies. Serum MYOM3, CCL2 and MSTN are good biomarkers of the DE50-MD phenotype that are unaffected by the relatively low level exertion performed in the 6MWT by 12-month-old DE50-MD dogs.
杜氏肌营养不良症（DMD）是一种致命的肌肉萎缩疾病，由肌营养不良蛋白基因突变引起，导致肌肉退化、炎症和再生循环。6分钟步行试验（6MWT）是DMD患者临床试验的关键功能结局指标，并已适用于该疾病的动物模型。DMD的DE50-MD犬模型在丧失行走能力之前密切反映了DMD患者的表型。对于使用该模型的临床前试验，必须建立功能结局指标。
这项纵向研究比较了DE50-MD犬和野生型（WT）对照犬在6MWT中的行走距离，并评估了6MWT作为功能生物标志物的效用。犬在3、6、9、12、15和18月龄时，相隔约48小时进行两次6MWT。此外，我们评估了12月龄的DE50-MD犬和WT犬在6MWT后0、3、6、24和48小时选定血源生物标志物的稳定性。
在所有时间点，DE50-MD犬的6分钟步行距离（6MWD）均显著短于WT犬（P<0.05），第一次和第二次6MWT之间的6MWD无差异。C-C基序趋化因子配体2（CCL2）、肌间蛋白-3（MYOM3）和肌肉生长抑制素（MSTN）是DE50-MD表型的生物标志物，在6MWT后，DE50-MD犬体内这些标志物保持不变，而在DE50-MD犬中，肌酸激酶（CK）活性在试验后3小时显著增加，而WT犬则保持不变。
6MWT能有效区分3至18月龄的DE50-MD犬和WT犬，单次6MWT足以用于未来研究。血清MYOM3、CCL2和MSTN是DE50-MD表型的良好生物标志物，不受12月龄DE50-MD犬在6MWT中相对较低运动强度的影响。
