Cryopreservation of human skeletal muscle impairs mitochondrial function

Area of Science:

• Cellular Biology
• Mitochondrial Physiology
• Cryobiology

Background:

• Mitochondrial functional analysis is crucial for understanding cellular energy metabolism.
• Previous research on cryopreservation of mitochondria yielded conflicting results across different tissues.
• Long-term cryopreservation effects on human skeletal muscle mitochondria remain unclear.

Purpose of the Study:

• To assess the functional integrity of mitochondria in human skeletal muscle following one year of cryopreservation.
• To determine the impact of cryopreservation on mitochondrial respiration and oxidative phosphorylation capacity.
• To investigate potential mechanisms of mitochondrial dysfunction post-cryopreservation.

Main Methods:

• Human skeletal muscle samples were cryopreserved for one year using dimethyl sulfoxide (DMSO).
• Thawed muscle fibers were permeabilized with saponin.
• Mitochondrial respiration was measured using high-resolution respirometry.

Main Results:

• A significant reduction in oxidative phosphorylation capacity was observed in cryopreserved samples (P < 0.05).
• Respiration linked to Complex I was more impaired than Complex II following cryopreservation (P < 0.05).
• Addition of cytochrome c indicated mitochondrial loss of this essential respiratory protein.

Conclusions:

• Cryopreservation for one year does not maintain normal mitochondrial functionality in human skeletal muscle.
• The study highlights significant impairment of mitochondrial respiration and potential damage to the electron transport chain.
• Findings suggest cryopreservation is not a suitable method for preserving functional mitochondria in skeletal muscle for later analysis.