Related Experiment Video
Updated: May 16, 2026
Assessing Functional Performance in the Mdx Mouse Model
Published on: March 27, 2014
Loss of cIAP1 attenuates soleus muscle pathology and improves diaphragm function in mdx mice
Emeka K Enwere1, Louise Boudreault, Janelle Holbrook
1Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada.
Abstract:
The cellular inhibitor of apoptosis 1 (cIAP1) protein is an essential regulator of canonical and noncanonical nuclear factor κB (NF-κB) signaling pathways. NF-κB signaling is known to play important roles in myogenesis and degenerative muscle disorders such as Duchenne muscular dystrophy (DMD), but the involvement of cIAP1 in muscle disease has not been studied directly. Here, we asked whether the loss of cIAP1 would influence the pathology of skeletal muscle in the mdx mouse model of DMD. Double-mutant cIAP1(-/-);mdx mice exhibited reduced muscle damage and decreased fiber centronucleation in the soleus, compared with single-mutant cIAP1(+/+);mdx mice. This improvement in pathology was associated with a reduction in muscle infiltration by macrophages and diminished expression of inflammatory cytokines such as IL-6 and tumor necrosis factor-α. Furthermore, the cIAP1(-/-);mdx mice exhibited reduced serum creatine kinase, and improved exercise endurance associated with improved exercise resilience by the diaphragm. Mechanistically, the loss of cIAP1 was sufficient to drive constitutive activation of the noncanonical NF-κB pathway, which led to increased myoblast fusion in vitro and in vivo. Collectively, these results show that the loss of cIAP1 protects skeletal muscle from the degenerative pathology resulting from systemic loss of dystrophin.
Insights
Loss of cellular inhibitor of apoptosis 1 (cIAP1) protein ameliorates Duchenne muscular dystrophy (DMD) pathology in mdx mice. This protection involves reduced inflammation and improved muscle function, highlighting cIAP1 as a therapeutic target for DMD.
Area of Science:
- Muscle biology
- Immunology
- Molecular signaling
Background:
- Cellular inhibitor of apoptosis 1 (cIAP1) regulates nuclear factor κB (NF-κB) pathways.
- NF-κB signaling is implicated in muscle development and degenerative muscle disorders like Duchenne muscular dystrophy (DMD).
- The role of cIAP1 in muscle disease remained uninvestigated.
Purpose of the Study:
- To investigate the impact of cIAP1 deficiency on skeletal muscle pathology in the mdx mouse model of DMD.
- To elucidate the molecular mechanisms underlying cIAP1's influence on DMD.
Main Methods:
- Generation of double-mutant cIAP1(-/-);mdx mice.
- Assessment of muscle damage, fiber centronucleation, macrophage infiltration, and inflammatory cytokine expression (IL-6, TNF-α).
- Measurement of serum creatine kinase levels and evaluation of exercise endurance and diaphragm resilience.
Main Results:
- cIAP1(-/-);mdx mice showed reduced muscle damage and centronucleation in the soleus muscle.
- Pathology improvement correlated with decreased macrophage infiltration and lower IL-6 and TNF-α expression.
- These mice exhibited lower serum creatine kinase, enhanced exercise endurance, and improved diaphragm resilience.
- Loss of cIAP1 led to constitutive noncanonical NF-κB pathway activation, promoting myoblast fusion.
Conclusions:
- Loss of cIAP1 confers protection against skeletal muscle degeneration in the context of dystrophin deficiency.
- cIAP1 inhibition represents a potential therapeutic strategy for Duchenne muscular dystrophy.
