Optical redox imaging of ANT1-deficient muscles

Area of Science:

• Mitochondrial physiology
• Cellular metabolism
• Biophysics

Background:

• Adenine nucleotide translocator (ANT) facilitates ADP/ATP exchange across the mitochondrial inner membrane, crucial for cellular energy.
• ANT1 isoform is predominant in cardiac and skeletal muscles.
• ANT1 mutations are linked to mitochondrial and neuromuscular disorders.

Purpose of the Study:

• To investigate the impact of ANT1 deletion on the mitochondrial redox state in mice.
• To compare the redox state of heart and quadriceps muscles in ANT1-deficient and wild-type mice.

Main Methods:

• Utilized 3D optical redox imaging with a Chance redox scanner on snap-frozen heart and quadriceps tissues from ANT1-deficient and wild-type mice.
• Analyzed redox indices including NADH, flavin adenine dinucleotide-containing flavoproteins (Fp), and the Fp/(NADH+Fp) redox ratio.

Main Results:

• No significant differences in overall redox indices (NADH, Fp, redox ratio) were observed between ANT1-deficient and wild-type groups.
• Quadriceps muscles exhibited higher Fp levels than heart muscles in both groups.
• Quadriceps muscles were more oxidized (higher redox ratio) than heart muscles in wild-type mice, a difference potentially diminished in ANT1-deficient mice.

Conclusions:

• ANT1-deficient muscle cells maintain a similar mitochondrial redox state to wild-type cells under non-stressful conditions.
• ANT1 deficiency may attenuate the distinct mitochondrial redox differences observed between cardiac and skeletal muscles in wild-type individuals.
• Future studies could explore muscle redox imaging under physical stress.