Characterizing age-related changes in intact mitochondrial proteoforms in murine hearts using quantitative top-down...

Area of Science:

• Proteomics
• Mitochondrial Biology
• Cardiovascular Aging

Background:

• Cardiovascular diseases (CVDs) increase with age, linked to mitochondrial dysfunction.
• The heart's high energy demand makes it sensitive to mitochondrial dysfunction.
• Cardiac mitochondrial proteome complexity and age-related changes are not fully understood.

Purpose of the Study:

• To investigate age-related changes in intact mitochondrial proteoforms in the heart.
• To identify alterations in protein abundance and post-translational modifications (PTMs) during cardiac aging.
• To apply top-down proteomics for comprehensive cardiac mitochondrial proteome analysis.

Main Methods:

• Isolated intact mitochondria from young and old mouse hearts.
• Utilized quantitative top-down proteomics (LC-MS/MS) with label-free quantitation.
• Identified and quantified proteoforms and their PTMs in cardiac mitochondria.

Main Results:

• Identified 134 unique mitochondrial proteins and 823 unique proteoforms.
• Detected significant age-related changes in proteoform abundance (7 increased, 13 decreased).
• Characterized PTMs including acetylation, succinylation, oxidation, and phosphorylation in aged cardiac mitochondria.

Conclusions:

• Top-down proteomics successfully identified and quantified intact proteoforms in the cardiac mitochondrial proteome.
• This approach revealed age-related alterations in proteoform abundance and PTMs in the heart.
• The findings provide insights into mitochondrial changes during cardiac aging.