Quantitative iTRAQ-based proteomic analysis of differentially expressed proteins in aging in human and monkey

Area of Science:

• Proteomics
• Aging Research
• Comparative Biology

Background:

• The physiological mechanisms of aging remain incompletely understood.
• The circulatory system's role in aging is significant but requires further elucidation.
• This study investigates age-related changes in plasma proteins.

Purpose of the Study:

• To identify differentially expressed proteins in human and monkey plasma between young and aged individuals.
• To validate candidate proteins using Western blotting and behavioral experiments.
• To explore the role of specific proteins in the aging process.

Main Methods:

• Isobaric tags for relative and absolute quantification (iTRAQ) for plasma proteomics.
• Comparative analysis of protein expression in young versus aged humans and monkeys.
• Western blotting and behavioral studies in mice for validation.

Main Results:

• 74 and 69 differentially expressed proteins were identified in humans and monkeys, respectively.
• Insulin-like Growth Factor Binding Protein 4 (IGFBP4) was consistently upregulated in aged humans and monkeys.
• IGFBP4 treatment in mice replicated aging-related cognitive dysfunction.

Conclusions:

• Integrated proteomics identified IGFBP4 as a protein that promotes aging.
• Western blotting and behavioral analysis confirmed IGFBP4's role in aging.
• Proteolytic systems and inflammatory responses are implicated in the aging process.