Presence of β-citryl- l-glutamic acid in the lens: its possible role in the differentiation of lens epithelial cells into fiber cells

• Published in: Experimental eye research 1995-10, Vol.61 (4), p.403-411
• Main Authors: Tsumori, Mitsuru, Asakura, Masahiro, Narahara, Masanori, Ogawa, Tomoko, Nakae, Masuo, Nakagawa, Shinsaku, Kawai, Yuichi, Morino, Hideo, Hama, Takao, Miyak, Masaharu
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Brain - embryology; Brain - metabolism; Cataract - metabolism; Cattle; Cell Differentiation; Cells, Cultured; Chickens; Decapodiformes; differentiation; Epithelial Cells; Eye - chemistry; Eye - embryology; Eye and associated structures. Visual pathways and centers. Vision; Fishes; Fundamental and applied biological sciences. Psychology; Glutamates - analysis; Glutamates - metabolism; Glutamates - physiology; lens; Lens Cortex, Crystalline - chemistry; lens epithelial cells; lens fiber cell; Lens, Crystalline - chemistry; Lens, Crystalline - cytology; Male; Mice; Rabbits; Rana catesbeiana; Rats; Species Specificity; Vertebrates: nervous system and sense organs; β-Citryl- l-glutamate
• ISSN: 0014-4835; 1096-0007
• DOI: 10.1016/S0014-4835(05)80135-6

The β-CG concentration in the chicken brain was high during embryonic development and decreased rapidly to a lower level close to hatching, while the concentration in the eyeball which was also high during the embryonic life retained a fairly high level after hatching. The distribution of β-CG in the bovine eye was determined. About 95% of total β-CG content in the whole eye was localized in the lens. However, the distribution of β-CG in the eye varied depending on species. β-CG was exclusively localized in the lens in the eyes of fish and mammals, but distributed in both lens and retina in frogs. The molecule was localized in the retina rather than the lens in the chicken eye, although the concentrations was extremely low compared to those in the mammalian, amphibian and fish eyes. It was found that β-CG is present ubiquitously in the lens or retina in various species. The distribution of β-CG in the bovine lens was determined in the three cortex regions and nucleus. β-CG was present at the highest concentration in the equatorial cortex, at a moderate concentration in the posterior and anterior cortex, and at the lowest concentration in the nucleus. Similar distribution patterns were also found in the rabbit and rat lens. When embryonic chick lens epithelial cells were cultured in the presence of fetal calf serum, the cells elongated, differentiated into fiber cells and formed lentoid bodies. The cells of lentoid bodies were stained strongly by the anti- β-CG antibody, while cells around the structures were not. In addition, the β-CG content in the lenses from the galactose cataractous rat decreased to about 20–30% of that in the normal lens. These findings suggest that β-CG may play a role in the differentiation of epithelial cells into fiber cells.