Hallmarks of aging: A user's guide for comparative biologists

Area of Science:

• Gerontology
• Comparative Biology
• Molecular Biology

Background:

• The hallmarks of aging framework (2013/2014) guides aging research across tissues and conditions.
• This framework, primarily derived from human and rodent studies, requires validation across diverse species.
• Comparative aging studies offer insights into mechanistic foundations due to species' lifespan and physiological diversity.

Purpose of the Study:

• To review the twelve hallmarks of aging (Lopez-Otin, 2023) regarding data availability in diverse species.
• To evaluate current methods for assessing hallmarks and their adaptability for comparative studies.
• To identify research gaps and prioritize future comparative aging studies.

Main Methods:

• Systematic review of existing literature on the twelve hallmarks of aging.
• Assessment of data availability across diverse animal clades for each hallmark.
• Evaluation of current methodologies for hallmark assessment and their comparative applicability.

Main Results:

• Data supporting the hallmarks of aging are predominantly from humans and limited model systems, with sparse data in many animal groups.
• Not all hallmarks are easily assessable across diverse species using current methods.
• Methods exist to study at least half of the hallmarks comparatively, providing a foundation for future research.

Conclusions:

• The current understanding of aging hallmarks is largely anthropocentric and requires expansion through comparative studies.
• Prioritizing research on hallmarks with available comparative assessment methods is crucial.
• Development of new methodologies is needed to fully explore aging mechanisms across the tree of life.