Related Experiment Video
Updated: Aug 6, 2026
Measuring Neuromuscular Junction Functionality
Published on: August 6, 2017
Acute mitochondrial dysfunction impairs neuromuscular transmission and contractility in mouse diaphragm: the
Eva A Kapliukhina1, Nikita S Fedorov1, Andrei N Tsentsevitsky1
1Laboratory of Biophysics of Synaptic Processes, Kazan Institute of Biochemistry and Biophysics, Federal Research Center "Kazan Scientific Center of RAS", 2/31 Lobachevsky St, Kazan, 420111, Russia.
Abstract:
Mitochondrial impairment, accompanied by excessive reactive oxygen species (ROS) production, is a key contributor to muscle atrophy and neuromuscular disorders, leading to locomotor and respiratory failure. Antimycin A (AA), an inhibitor of the electron transport chain complex III, is an effective tool to mimic mitochondrial dysfunction, whereas 25-hydroxycholesterol (25-HC) is an immune-related oxysterol that can modulate neuromuscular activity via the membrane estrogen receptor α (ERα)/inositol triphosphate receptor/cytoplasmic Ca2+ axis. Herein, we investigated the effects of AA treatment in mouse diaphragm nerve-muscle preparations and tested the hypothesis that 25-HC can mitigate AA-induced mitochondrial damage. AA increased mitochondrial ROS production and reduced mitochondrial Ca2+ levels and membrane potential. This was accompanied by an elevation of extracellular H2O2 levels and lipid peroxidation, as well as a decline in both muscle fiber contractility and evoked exocytosis at the neuromuscular junction (NMJ). Furthermore, alterations were observed in the shape of miniature end-plate responses to the release of single neurotransmitter quanta. 25-HC, at a submicromolar concentration, inhibited AA-induced mitochondrial dysfunction and oxidative stress. Additionally, 25-HC alleviated AA-dependent functional NMJ disturbances but did not reverse the muscle fiber contraction deficit. The ability of 25-HC to decrease AA-driven mitochondrial ROS generation was blocked by a selective ERα antagonist and by chelation of cytoplasmic Ca2+. Thus, AA induces mitochondrial damage accompanied by oxidative stress, contractile and NMJ impairments. 25-HC can counteract AA-mediated mitochondrial dysfunction and partially restore NMJ function.
Insights
Mitochondrial dysfunction from Antimycin A causes muscle and nerve damage. 25-hydroxycholesterol partially reverses nerve junction issues by reducing oxidative stress, but doesn't fix muscle contraction problems.
Area of Science:
- Neuroscience
- Mitochondrial Biology
- Muscle Physiology
Background:
- Mitochondrial impairment and reactive oxygen species (ROS) contribute to muscle atrophy and neuromuscular disorders.
- Antimycin A (AA) models mitochondrial dysfunction, while 25-hydroxycholesterol (25-HC) influences neuromuscular activity.
Purpose of the Study:
- To investigate AA's effects on diaphragm nerve-muscle preparations.
- To test if 25-HC can mitigate AA-induced mitochondrial damage and neuromuscular junction (NMJ) dysfunction.
Main Methods:
- Utilized mouse diaphragm nerve-muscle preparations.
- Administered Antimycin A (AA) to induce mitochondrial dysfunction.
- Assessed mitochondrial ROS, Ca2+ levels, membrane potential, oxidative stress markers, and NMJ function.
Main Results:
- AA increased mitochondrial ROS, extracellular H2O2, and lipid peroxidation, while decreasing mitochondrial Ca2+ and membrane potential.
- AA impaired muscle fiber contractility and NMJ evoked exocytosis.
- 25-HC inhibited AA-induced mitochondrial dysfunction and oxidative stress, partially restoring NMJ function but not muscle contractility.
Conclusions:
- AA induces mitochondrial damage, oxidative stress, and functional deficits at both muscle fibers and NMJs.
- 25-HC counteracts AA-mediated mitochondrial dysfunction and partially restores NMJ function, indicating a therapeutic potential for ERα/Ca2+ signaling pathways.
