PGC-1α regulates mitochondrial properties beyond biogenesis with aging and exercise training

Area of Science:

• Mitochondrial biology
• Skeletal muscle physiology
• Aging research

Background:

• Impaired mitochondrial function contributes to age-associated metabolic diseases.
• Exercise training enhances mitochondrial biogenesis via PGC-1α.
• The role of mitochondrial ADP sensitivity and ROS in aging is unclear.

Purpose of the Study:

• Investigate aging and exercise effects on mitochondrial properties beyond biogenesis.
• Examine PGC-1α's role in mitochondrial function during aging and exercise.
• Clarify mechanisms linking mitochondrial ADP sensitivity, ROS, and aging.

Main Methods:

• Utilized inducible muscle-specific PGC-1α-knockout and control mice.
• Assessed mitochondrial respiratory capacity, ADP sensitivity, and ROS emission.
• Analyzed mitochondrial network structure and adenine nucleotide translocase 1 modifications.

Main Results:

• Aged mice showed reduced endurance, respiratory capacity, and mitochondrial network integrity.
• Exercise training improved maximal respiration independently of PGC-1α.
• PGC-1α was essential for exercise-induced improvements in submaximal respiration and network structure.
• PGC-1α deficiency altered ADP/ATP exchanger function and increased ROS.

Conclusions:

• PGC-1α plays a critical role in regulating mitochondrial network structure and ADP-stimulated respiration in aging muscle.
• Exercise training mitigates age-related mitochondrial dysfunction in a PGC-1α-dependent manner.
• PGC-1α influences mitochondrial ROS emission and oxidative stress during aging and exercise.