Mitochondrial dysfunction causes Ca²⁺ overload and ECM degradation-mediated muscle damage in C. elegans

Area of Science:

• Cellular Biology
• Biochemistry
• Genetics

Background:

• Mitochondrial dysfunction is linked to muscle wasting and impaired muscle health.
• The precise mechanisms by which mitochondrial dysfunction signals muscle cell damage are not fully understood.

Purpose of the Study:

• To investigate the role of mitochondrial dysfunction in extracellular matrix (ECM) proteolysis and muscle dystrophy.
• To identify intramuscular signaling pathways triggered by mitochondrial dysfunction leading to muscle damage.

Main Methods:

• Inhibition of the mitochondrial electron transport chain in *Caenorhabditis elegans*.
• Assessment of muscle structural integrity, paralysis, and collagen content.
• Utilizing collagen IV overexpression and inhibitors of matrix metalloproteinase (MMP) and Furin.
• Monitoring muscle cytosolic calcium levels.

Main Results:

• Inhibition of mitochondrial respiration induced paralysis and muscle structural damage, correlated with reduced collagen.
• Overexpression of collagen IV and inhibition of MMP/Furin rescued muscle damage in treated *C. elegans* models.
• Increased muscle cytosolic calcium was observed, and its reduction ameliorated muscle damage.

Conclusions:

• Mitochondrial dysfunction triggers muscle damage through extracellular matrix (ECM) degradation.
• Calcium overload acts as an early signal, activating Furin and MMPs to degrade collagen.
• ECM degradation is a significant pathway contributing to muscle damage, offering potential therapeutic targets.