Journal ArticleDOI
Glycated proteins can enhance photooxidative stress in aged and diabetic lenses.
TLDR
The documented glycation-related photosensitization could explain the accelerated pathogenic changes in human lens at advanced age and under diabetic conditions.Abstract:
This study intends to clarify the ability of different carbonyl-containing lens metabolites to form advanced glycation end products, which possess photosensitizer activity and to investigate whether these modified proteins could be implicated in lens photodamage. Calf lens protein was experimentally glycated with either methylglyoxal, glyoxal, ascorbic acid, or fructose to obtain models of aged and diabetic cataractous lenses. Being exposed to 200 J/cm 2 UVA radiation the model glycated proteins produced 2-3-fold more singlet oxygen compared to the unmodified protein and the superoxide radical formation was 30-80% higher than by the native protein. Ascorbylated proteins demonstrated the highest photosensitizer activity. Biological responses of glycation-related photosensitizers were studied on cultured lens epithelial cells irradiated with 40 J/cm 2 UVA. Tissue culture studies revealed a significant increase in thiobarbituric acid reactive substances in the culture medium of lens epithelial cells after ir...read more
Citations
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Journal ArticleDOI
Five years of research on health risks and benefits of Maillard reaction products: an update.
TL;DR: Substantial knowledge on the health effects of melanoidins has been gained within the COST Action 919, but still, further studies are needed to distinguish between chemically identified harmful and health-beneficial melanoids.
Journal ArticleDOI
The maillard reaction in eye diseases.
TL;DR: This review evaluates the ever‐growing literature on AGEs in biological systems and draws relevant links to diseases such as diabetic retinopathy, age‐related macular degeneration, and cataract formation and outlines recent pharmaceutical strategies to inhibit Maillard reaction products.
Journal ArticleDOI
The pathogenic role of Maillard reaction in the aging eye
TL;DR: This review outlines recent advances in AGE research focusing on the mechanisms of their formation and their role in cataract and pathologies of the retina and the therapeutic action and pharmacological strategies of anti-AGE agents that can inhibit or prevent AGE formation in the eye.
Journal ArticleDOI
Age-related changes of alpha-crystallin aggregate in human lens
Noriko Fujii,Yoshiari Shimmyo,Miyo Sakai,Yutaka Sadakane,T. Nakamura,Yukio Morimoto,Tadatoshi Kinouchi,Yuji Goto,Kirsten J. Lampi +8 more
TL;DR: Alpha-crystallin from young donors, and recombinant alpha A- and alpha B-Crystallin and their mixtures showed chaperone activity, which was markedly lost in samples from the aged alpha- Crystallin aggregates.
Journal ArticleDOI
Photodynamics of cataract: an update on endogenous chromophores and antioxidants.
TL;DR: A list of accumulant chromophores that have been identified in aging and cataract human lenses and their roles as potential sensitizers, antioxidants or as benign filters are summarized.
References
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PatentDOI
Measurement of protein using bicinchoninic acid
TL;DR: This new method maintains the high sensitivity and low protein-to-protein variation associated with the Lowry technique and demonstrates a greater tolerance of the bicinchoninate reagent toward such commonly encountered interferences as nonionic detergents and simple buffer salts.
Journal ArticleDOI
Formation of glyoxal, methylglyoxal and 3-deoxyglucosone in the glycation of proteins by glucose.
TL;DR: Alpha-Oxoaldehydes were formed in early glycation from the degradation of glucose and Schiff's base adduct, which suggests that short periods of hyperglycaemia, as occur in impaired glucose tolerance, may be sufficient to increase the concentrations of alpha-oxoaldeHydes in vivo.
Journal ArticleDOI
Role of the Maillard Reaction in Aging of Tissue Proteins ADVANCED GLYCATION END PRODUCT-DEPENDENT INCREASE IN IMIDAZOLIUM CROSS-LINKS IN HUMAN LENS PROTEINS
TL;DR: The presence of GOLD and MOLD in tissue proteins implicates methylglyoxal and glyoxal, either free or protein-bound, as important precursors of protein cross-links formed during Maillard reactions in vivo during aging and in disease.
Journal ArticleDOI
UVA radiation-induced oxidative damage to lipids and proteins in vitro and in human skin fibroblasts is dependent on iron and singlet oxygen.
Glenn F. Vile,Rex M. Tyrrell +1 more
TL;DR: It is concluded that iron, singlet oxygen, and hydrogen peroxide are important redox active species involved in the deleterious effects of UVA radiation on lipids and proteins of human skin cells.
Journal Article
The search for a solution to senile cataracts. Proctor lecture.
TL;DR: Measurements suggest that after the first few years of life, the water soluble protein fraction appears to remain relatively constant in abundance while there is an increasing accumulation of water insoluble protein.
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