Motor Physical Therapy Affects Muscle Collagen Type I and Decreases Gait Speed in Dystrophin-Deficient Dogs

Abstract

Golden Retriever Muscular Dystrophy (GRMD) is a dystrophin-deficient canine model genetically homologous to Duchenne Muscular Dystrophy (DMD) in humans. Muscular fibrosis secondary to cycles of degeneration/regeneration of dystrophic muscle tissue and muscular weakness leads to biomechanical adaptation that impairs the quality of gait. Physical therapy (PT) is one of the supportive therapies available for DMD, however, motor PT approaches have controversial recommendations and there is no consensus regarding the type and intensity of physical therapy. In this study we investigated the effect of physical therapy on gait biomechanics and muscular collagen deposition types I and III in dystrophin-deficient dogs. Two dystrophic dogs (treated dogs-TD) underwent a PT protocol of active walking exercise, 3×/week, 40 minutes/day, 12 weeks. Two dystrophic control dogs (CD) maintained their routine of activities of daily living. At t0 (pre) and t1 (post-physical therapy), collagen type I and III were assessed by immunohistochemistry and gait biomechanics were analyzed. Angular displacement of shoulder, elbow, carpal, hip, stifle and tarsal joint and vertical (Fy), mediolateral (Fz) and craniocaudal (Fx) ground reaction forces (GRF) were assessed. Wilcoxon test was used to verify the difference of biomechanical variables between t0 and t1, considering p<.05. Type I collagen of endomysium suffered the influence of PT, as well as gait speed that had decreased from t0 to t1 (p<.000). The PT protocol employed accelerates morphological alterations on dystrophic muscle and promotes a slower velocity of gait. Control dogs which maintained their routine of activities of daily living seem to have found a better balance between movement and preservation of motor function.

Fisioterapia en Animales Domésticos: ¿Qué dice la evidencia?

“…Aunque existe información, los autores resaltan que se necesitan hacer más investigaciones con el fin de ampliar y enriquecer el conocimiento con respecto al tema a nivel mundial. (Crook, McGowan, & Pead, 2007;Gaiad, Araujo, Serrão, Miglino, & Ambrósio, 2014;Gruenenfelder, Boos, Mouwen, & Steffen, 2006;Challande Kathmann, Cizinauskas, Doherr, Steffen, & Jaggy, 2006…”

Night Activity Reduction is a Signature Physiological Biomarker for Duchenne Muscular Dystrophy Dogs

“…Third, some of these assays (such as single muscle in situ force measurement) are terminal assays and can only be performed once in a subject before euthanization [8]. Non-invasive goniometry and accelerometry were developed recently to evaluate the range of motion of a joint and the gait pattern [10, 22–25]. These non-invasive assays had minimum risks and they can also be performed repeatedly in the same dog to monitor disease progression or responses to experimental therapy.…”

Low-intensity training provokes adaptive extracellular matrix turnover of a muscular dystrophy model

“…CLN is a parameter widely used in mdx model studies to demonstrate the efficacy of preclinical studies of DMD ( Briguet et al, 2004 ; Dubach-Powell, 2014 ). Muscular fibrosis is also a result of an aberrant process of muscle repair in dystrophic muscle ( Gosselin et al, 2007 ; Mann et al, 2011 ) and types I and III collagen are two common types of collagen fibers that have been investigated to verify the influence of different therapies on skeletal dystrophic muscle ( Gaiad et al, 2014 ; Huebner et al, 2008 ; Turgeman et al, 2008 ). The location of these types of collagen fibers in dystrophic muscle through immunohistochemistry analysis and the quantification of their proportion in the skeletal muscle can bring some knowledge about the dystrophic muscle repair submitted to LIT protocol.…”