Macromolecular deterioration as the ultimate constraint on human lifespan

Area of Science:

• Biogerontology
• Molecular Biology
• Human Physiology

Background:

• Long-lived proteins are abundant in vital human organs like the heart, lungs, and brain.
• Accumulation of protein modifications over decades may alter tissue properties and affect health.
• The human lens, with non-turnover proteins, serves as a model for studying age-related protein deterioration.

Purpose of the Study:

• To investigate the impact of accumulated protein modifications on long-lived tissues.
• To elucidate the mechanisms behind age-related protein deterioration.
• To highlight the necessity of long-lived animal models for studying aging.

Main Methods:

• Analysis of protein modifications in long-lived tissues, particularly the human lens.
• Post-translational modification analysis, including truncation, racemization, and deamidation.
• Comparative studies utilizing organisms with lifespans measured in decades.

Main Results:

• Intrinsic instability of certain amino acid residues contributes to protein truncation, racemization, and deamidation.
• These post-translational modifications accumulate over many years.
• The human lens exemplifies age-related protein damage due to these modifications.

Conclusions:

• Gradual, deleterious modifications to long-lived proteins are a primary driver of age-related tissue deterioration.
• Studying these aging processes necessitates the use of long-lived animal models.
• Key aspects of human aging may only be fully understood through research on species with extended lifespans.