NF-κB inhibition rescues cardiac function by remodeling calcium genes in a Duchenne muscular dystrophy model

Area of Science:

• Cardiovascular Biology
• Molecular Biology
• Genetics

Background:

• Duchenne muscular dystrophy (DMD) causes progressive muscle degeneration, with cardiomyopathy being a primary cause of mortality.
• The precise mechanisms driving heart failure in DMD remain incompletely understood.
• Previous research implicated NF-κB in exacerbating skeletal muscle pathology in DMD.

Purpose of the Study:

• To investigate the role of NF-κB in the pathogenesis of DMD-associated cardiomyopathy.
• To determine if inhibiting NF-κB in the heart can ameliorate cardiac dysfunction in a mouse model of DMD.

Main Methods:

• Activation of NF-κB was assessed in the hearts of dystrophic (mdx) mice.
• Cardiac function was evaluated following cardiomyocyte-specific ablation of NF-κB in mdx mice.
• Chromatin modifications, gene expression (particularly calcium genes), and levels of specific transcriptional repressors were analyzed.

Main Results:

• NF-κB is activated in the hearts of mdx mice.
• Ablation of NF-κB in cardiomyocytes significantly rescued cardiac function in mdx mice.
• Improved cardiac function was linked to upregulated calcium genes, enriched H3K27 acetylation marks, and reduced levels of CTCF, SIN3A, and HDAC1.

Conclusions:

• NF-κB plays a critical role in the cardiac pathology of Duchenne muscular dystrophy.
• In the context of DMD hearts, NF-κB appears to function uniquely by inducing global chromatin changes that affect calcium handling and cardiac function.
• Targeting NF-κB presents a potential therapeutic strategy for DMD-related cardiomyopathy.