Age-Related Changes in the Metabolomic Composition of Macaque (Macaca fascicularis) Ocular Tissues

The study is aimed at determining age-related changes in ocular tissues of crab-eating macaque (Macaca fascicularis). To this end, we measured the concentrations of a total of 71 major metabolites in aqueous humor, vitreous humor, and lens of two groups of animals, young (4-year-old, n = 6) and aged (21-year-old and 27-year-old, n = 2) macaques. Significant age-related changes were revealed for all three tissues. In the lens, the most significant changes were found for cytoprotective compounds - antioxidants, osmolytes, and molecular ultraviolet (UV) filters: the concentrations of these metabolites in the lenses of aged animals are much lower. The observed changes contribute to increased oxidative stress and predispose the lens to the development of cataracts. The majority of cytoprotective metabolites are synthetized in the lens epithelium. Findings of this work indicate that the observed age-related changes may be caused by the impairment of the lens epithelial cells leading to the increase of oxidative stress in the lens nucleus and developing of age-related cataracts.