Endomysial Fibrosis, Muscular Inflammatory Response and Calcium Homeostasis Dysfunction in Duchenne Muscular Dystrophy

Study Overview
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Brief Summary
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Duchenne muscular dystrophy (DMD) is the most common and devastating form of muscular dystrophy, caused by an X-chromosome gene mutation resulting in the absence of the protein dystrophin. Gene therapy by exon skipping or stop codon read-through and cell therapy are at the stage of clinical assays with very promising results. Nevertheless, they will not allow a complete cure of DMD patients and they will concern only specific types of mutations. It is therefore crucial to develop other therapeutic strategies related to the natural history of the disease and targeted not on the dystrophin itself, but on the consequences of its absence. Another crucial pathophysiological pathway in DMD is muscle cell calcium homeostasis, particularly via the ryanodine recepteur (RyR1). Our study focus on the relationship between endomysial fibrosis, abnormal inflammation response and calcium homeostasis dysfunction which are not entirely established in DMD. The identification of the biological mechanisms that play a role in the severity of the phenotype, particularly endomysial fibrosis, should allow the development of targeted pharmacotherapy as a complementary strategy for the future treatment of DMD.

Official Title
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Endomysial Fibrosis, Muscular Inflammatory Response and Calcium Homeostasis Dysfunction : Potential Links and Targeted Pharmacotherapy in Duchenne Muscular Dystrophy (DMD).

Conditions
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Duchenne Muscular Distrophy (DMD)

Intervention / Treatment
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* Other: Muscle biopsy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Boy between 2 to 15 years old. Lack of any infectious disease in the last week before the study. Consent form signed by parents. Inclusion Criteria for DMD infant Clinical suspicion of Duchenne Muscular Dystrophy Inclusion Criteria for Control healthy Infant Lack of any antecedent of congenital cardiac, pulmonary or muscular disease including DMD. Exclusion Criteria: Subjects who are unable or unwilling to tolerate study constraints Parents of the subject unable or unwilling to undergo informed consent Subject with no rights from the national health insurance programme

Ages Eligible for Study
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Minimum Age: 2 Years
Maximum Age: 15 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: DMD infant<br>Muscle biopsy | Other: Muscle biopsy<br>* Muscle biopsy<br>|
| Other: Control infant<br>Muscle biopsy (during lower limb operation surgery for pure orthopedic causes) | Other: Muscle biopsy<br>* Muscle biopsy<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Quantification of endomysial fibrosis |  | 1 day (biopsy day) | 
| quantification of the muscle inflammation | Measure of the protein (Immunofluorescence and western blot) and mRNA (qRT-PCR) expression of the following markers of muscular inflammation response Presence and quantification of cellular partners of inflammation and muscle regeneration (M1 (CD68/KP1) and M2 (CD206) macrophages, quiescent and activated satellite cells (CD56/NCAM) and endothelial cells (CD31/PECAM-1)). | 1 day (biopsy day) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Duchenne muscular distrophy, Endomysial Fibrosis, Muscular Inflammatory Response, Calcium Homeostasis Dysfunction, Muscle biopsy