[Ocular diseases caused by accumulation of proteins with post-translational modifications].

Long-term duration of lifestyle-related diseases including diabetes induces various ocular diseases. For this reason, the development of lifestyle-related ocular diseases is closely related to the aging process. In the present study, we tried to reveal the molecular mechanism of lifestyle-related ocular diseases, especially diabetic complications of the eyes, in relation to aging. To unify the molecular mechanisms of diabetic complications and aging changes of the eyes, we focused on two kinds of nonenzymatic post-translational modification products: advanced glycation end products (AGEs) and D-amino acids. We found that the accumulation of proteins rich in AGEs and D-amino acids plays a central role in the development of both diabetic complications and such changes of the eyes as diabetic retinopathy, diabetic keratopathy, pinguecula, spheroidal degeneration of the cornea, and drusen. In addition, decreased function in AGE-modified and D-amino acid-containing proteins is a factor in the development of diabetic complications and aging changes in eyes. In this way, posttranslational changes in molecules and amino acids are important contributing factors in the development of diabetic complications and aging changes in eyes. In conclusion, accumulation of AGE-modified and D-amino acid-containing proteins is the molecular mechanism of both diabetic complications and the aging changes in eyes.