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Lens aging: effects of crystallins
K Krishna Sharma1, Puttur Santhoshkumar
1Department of Ophthalmology, University of Missouri-Columbia, 1 Hospital Drive, Columbia, MO 65212, USA. sharmak@health.missouri.edu
Biochimica Et Biophysica Acta
|May 26, 2009
Summary
Age-related changes to lens crystallin proteins, like deamidation and glycation, cause protein aggregation and lens opacity, leading to blindness. Understanding these modifications is key to combating cataracts.
Area of Science:
- Ophthalmology
- Biochemistry
- Molecular Biology
Background:
- The eye lens focuses light on the retina using crystallin proteins.
- Age-related modifications (oxidation, deamidation, glycation) accumulate in crystallins.
- These modifications lead to protein aggregation, light scattering, and lens opacity (cataracts).
Purpose of the Study:
- To review age-related modifications in lens crystallins, focusing on deamidation and glycation.
- To discuss the structural and functional consequences of these modifications.
- To explore the role of proteolysis and anti-chaperone activity in crystallin aggregation.
Main Methods:
- Review of existing literature on age-related crystallin modifications.
- Analysis of structural and functional changes in modified crystallins.
- Discussion of proteolysis and anti-chaperone mechanisms in lens aging.
- Evaluation of animal models for studying lens protein changes.
Main Results:
- Deamidation and glycation are key modifications affecting crystallin structure and function.
- Cumulative modifications lead to crystallin aggregation and lens opacity.
- Proteolysis generates fragments with anti-chaperone activity, promoting aggregation.
- Specific animal models show promise for studying these age-related changes.
Conclusions:
- Age-related crystallin modifications are the primary cause of cataracts, a leading cause of blindness.
- Understanding deamidation, glycation, and proteolysis is crucial for developing interventions.
- Hyperbaric oxygen-treated guinea pigs and 'humanized' mice are valuable models for research.
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