Activity, Motor Control & Coordination
Pain - Thermal Allodynia / Hyperalgesia
Pain - Spontaneous Pain - Postural Deficit
Pain - Mechanical Allodynia / Hyperalgesia
Anxiety & Depression Disorder
Learning/Memory - Attention - Addiction
Physiology & Respiratory Research
Metabolism - Food & Drink Intake
Pain
Metabolism
Motor control
Neurodegeneration
Cross-disciplinary subjects
Muscular system
General activity
Mood Disorders
Other disorders
Joints
Central Nervous System (CNS)
Sensory system
Authors
Taglietti, V., Kefi, K., Bronisz-Budzy_ska, I. et al.
Lab
Univ Paris-Est Creteil, INSERM, Creteil, France
Journal
Acta Neuropathologica Communications
Abstract
Duchenne muscular dystrophy (DMD) is a fatal muscle-wasting disorder caused by mutations in the Dystrophin gene and for which there is currently no cure. To bridge the gap between preclinical and therapeutic evaluation studies, we have generated a rat model for DMD that carries an exon 52 deletion (R-DMDdel52) causing a complete lack of dystrophin protein. Here we show that R-DMDdel52 animals recapitulated human DMD pathophysiological trajectory more faithfully than the mdx mouse model. We report that R-DMDdel52 rats displayed progressive and severe skeletal muscle loss associated with fibrotic deposition, fat infiltration and fibre type switch. Early fibrosis was also apparent in the cardiac muscle. These histological modifications led to severe muscle, respiratory and cardiac functional impairments leading to premature death around 1 year. Moreover, DMD muscle exhibited systemic inflammation with a mixed M1/M2 phenotype. A comparative single cell RNAseq analysis of the diaphragm muscle was performed, revealing cellular populations alteration and molecular modifications in all muscle cell types. We show that DMD fibroadipogenic progenitors produced elevated levels of cartilage oligomeric matrix protein, a glycoprotein responsible for modulating homeostasis of extracellular matrix, and whose increased concentration correlated with muscle fibrosis both in R-DMDdel52 rats and human patients. Fibrosis is a component of tissue remodelling impacting the whole musculature of DMD patients, at the tissue level but most importantly at the functional level. We therefore propose that this specific biomarker can optimize the prognostic monitoring of functional improvement of patients included in clinical trials.
BIOSEB Instruments Used:
Grip strength test (BIO-GS3)
