Increase in lens gangliosides due to aging and cataract progression in human senile cataract

Gangliosides were isolated from human senile cataractous lenses by solvent extraction, DEAE-Sephadex column chromatography, and thin-layer chromatography. The content and composition of gangliosides were examined in individual lens tissues. Three predominant gangliosides, GM3, GM1, and GD1a, were tentatively identified in comparison with authentic brain gangliosides, and several unidentified gangliosides were also recognized. The increase in ganglioside content per mg of protein content in cataractous lenses was found to be influenced by two physiologic parameters: aging and cataract progression. The mature cataractous lenses showed a higher ganglioside level on a protein basis than the immature lenses compared with the same age group. On the basis of statistical analysis, an age-dependent increase in ganglioside concentration was recognized in both mature and immature lens groups. The relative increase in slow-moving polysialogangliosides on thin-layer chromatography seemed to be caused by the maturation of cataract. The sugar composition of one of the polysialogangliosides was found to be glucose, galactose, and sialic acid in the molar ratio of 2:1:4; this suggests the presence of a unique ganglioside species in human cataractous lens.