Cytoprotective Compounds in the Primate Eye: Baseline Metabolomic Profiles of Macaca fascicularis Ocular Tissues

Nonhuman primates are often considered as the best animal models for studying human ophthalmological diseases, but the metabolomic composition of primate ocular tissues remains largely unknown. In this work, we performed NMR-based quantitative metabolomic analysis of crab-eating macaque (Macaca fascicularis) serum, aqueous (AH) and vitreous (VH) humors, and lens. We determined the concentrations of a total 94 compounds in these tissues, 13 of which play important cytoprotective roles. The obtained metabolomic profiles represent the baseline metabolomes of blood and eye tissues characteristic of young healthy M. fascicularis adults. The obtained data indicate that antioxidants ascorbate and ergothioneine are actively pumped from blood into AH with the use of specific transporters, and there is an active transport against the concentration gradient of amino acids from AH into the lens. The comparison of metabolomic profiles of M. fascicularis and human ocular tissues shows a very high degree of similarity at the qualitative level, while the quantitative compositions of cytoprotective compounds (antioxidants, osmolytes, and ultraviolet filters) in M. fascicularis and human lenses differ. Despite these differences, from the metabolomic viewpoint, M. fascicularis are much better models of human diseases than rodents, which are often used in studies of eye disorders.