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Updated: Jun 22, 2025
Assessing Functional Performance in the Mdx Mouse Model
Published on: March 27, 2014
A Novel MAO-B/SSAO Inhibitor Improves Multiple Aspects of Dystrophic Phenotype in mdx Mice
Francesca Gasparella1,2, Leonardo Nogara2,3,4, Elena Germinario2
1Department of Biology, University of Padova, 35131 Padova, Italy.
Abstract:
Duchenne muscular dystrophy (DMD) is one of the most frequent and severe childhood muscle diseases. Its pathophysiology is multifaceted and still incompletely understood, but we and others have previously shown that oxidative stress plays an important role. In particular, we have demonstrated that inhibition of mitochondrial monoamine oxidases could improve some functional and biohumoral markers of the pathology. In the present study we report the use of dystrophic mdx mice to evaluate the efficacy of a dual monoamine oxidase B (MAO-B)/semicarbazide-sensitive amine oxidase (SSAO) inhibitor, PXS-5131, in reducing inflammation and fibrosis and improving muscle function. We found that a one-month treatment starting at three months of age was able to decrease reactive oxygen species (ROS) production, fibrosis, and inflammatory infiltrate in the tibialis anterior (TA) and diaphragm muscles. Importantly, we also observed a marked improvement in the capacity of the gastrocnemius muscle to maintain its force when challenged with eccentric contractions. Upon performing a bulk RNA-seq analysis, PXS-5131 treatment affected the expression of genes involved in inflammatory processes and tissue remodeling. We also studied the effect of prolonged treatment in older dystrophic mice, and found that a three-month administration of PXS-5131 was able to greatly reduce the progression of fibrosis not only in the diaphragm but also in the heart. Taken together, these results suggest that PXS-5131 is an effective inhibitor of fibrosis and inflammation in dystrophic muscles, a finding that could open a new therapeutic avenue for DMD patients.
Insights
A new drug, PXS-5131, effectively reduced inflammation and fibrosis in Duchenne muscular dystrophy (DMD) mouse models. This dual inhibitor of monoamine oxidase B (MAO-B) and semicarbazide-sensitive amine oxidase (SSAO) shows promise for treating DMD.
Area of Science:
- Muscle physiology and pathology
- Pharmacology and drug discovery
- Biochemistry and molecular biology
Background:
- Duchenne muscular dystrophy (DMD) is a severe childhood genetic disorder characterized by progressive muscle degeneration.
- Oxidative stress and inflammation are key contributors to DMD pathophysiology.
- Previous research indicates mitochondrial monoamine oxidase inhibition can improve DMD markers.
Purpose of the Study:
- To evaluate the efficacy of PXS-5131, a dual MAO-B/SSAO inhibitor, in a mouse model of DMD.
- To assess PXS-5131's impact on inflammation, fibrosis, muscle function, and gene expression in dystrophic muscles.
- To investigate the effects of both short-term and prolonged PXS-5131 treatment.
Main Methods:
- Treatment of dystrophic mdx mice with PXS-5131 for one and three months.
- Assessment of reactive oxygen species (ROS) production, inflammatory infiltrate, and fibrosis.
- Evaluation of muscle function, specifically eccentric contraction force maintenance.
- Bulk RNA-sequencing analysis to identify affected gene pathways.
- Histological analysis of muscle and heart tissues.
Main Results:
- One-month PXS-5131 treatment reduced ROS, inflammation, and fibrosis in tibialis anterior and diaphragm muscles.
- Improved gastrocnemius muscle force maintenance during eccentric contractions was observed.
- RNA-seq revealed PXS-5131 modulated genes involved in inflammation and tissue remodeling.
- Three-month treatment significantly reduced fibrosis progression in the diaphragm and heart.
Conclusions:
- PXS-5131 demonstrates significant anti-inflammatory and anti-fibrotic effects in DMD mouse models.
- The drug improved muscle function and reduced disease progression markers.
- PXS-5131 represents a potential novel therapeutic strategy for Duchenne muscular dystrophy.
