Mitoquinone mesylate (MitoQ) prevents sepsis-induced diaphragm dysfunction

Area of Science:

• Mitochondrial Medicine
• Sepsis Pathophysiology
• Respiratory Physiology

Background:

• Sepsis frequently causes diaphragm dysfunction, leading to respiratory failure in mechanically ventilated patients.
• Diaphragm weakness in sepsis is linked to mitochondrial free radical generation.
• No pharmacological treatments currently exist for sepsis-induced diaphragm dysfunction.

Purpose of the Study:

• To investigate if mitoquinone mesylate (MitoQ), a mitochondrially targeted antioxidant, can prevent sepsis-induced diaphragm dysfunction.
• To assess the effects of MitoQ on diaphragm force generation, mitochondrial function, and oxidative stress markers in a mouse model of sepsis.

Main Methods:

• Male mice underwent cecal ligation and puncture (CLP) to induce sepsis or sham surgery.
• Mice received either saline or MitoQ (3.5 mg/kg/day) intraperitoneally.
• Diaphragm force, myosin heavy chain content, mitochondrial oxygen consumption (OCR), and aconitase activity were measured 48 hours post-surgery. Studies were also conducted in female mice and with endotoxin-induced sepsis.

Main Results:

• CLP significantly decreased diaphragm specific force generation, which was prevented by MitoQ treatment.
• MitoQ administration preserved mitochondrial oxygen consumption and aconitase activity, which were reduced by CLP.
• Similar protective effects of MitoQ were observed in female mice, endotoxin-induced sepsis, and with delayed treatment initiation.

Conclusions:

• MitoQ effectively prevents sepsis-induced diaphragm dysfunction in mice, preserving muscle force and mitochondrial integrity.
• MitoQ's ability to scavenge mitochondrial free radicals appears key to its protective effects.
• MitoQ shows potential as a therapeutic agent for preserving diaphragm function in critically ill sepsis patients.