concanavalin-a and Neuronal-Ceroid-Lipofuscinoses

Topics: Animals; Brain; Carbohydrate Sequence; Concanavalin A; Dolichol Phosphates; Glycoconjugates; Histocytochemistry; Humans; Molecular Sequence Data; Neuronal Ceroid-Lipofuscinoses; Oligosaccharides; Sheep

Concanavalin A (ConA) binding to lipopigments (LPs) of the lipofuscin type was proved to be due to the high content of mannose. The nature of the mannose bearing compound was twofold. One part was soluble in modified chloroform-methanol-water mixture (10:10:3) corresponding possibly to the oligosaccharyl diphosphodolichol (oligo-PP-Dol) described to be increased in LPs especially of inherited types. The second part, most probably a glycoprotein (GP), was entirely resistant to various extraction procedures. The ratio of the two components varied. The deposition of the typical lipofuscin (age pigment) was dominated by the GP component. Its amount was greatest in neurolipofuscin (especially in the olivary nucleus) and in the myocardium but very little in hepatocytic lipofuscin. In human neuronal ceroid lipofuscinoses (of early juvenile, and juvenile types) both components were found in large quantities in the storage granules of the affected neurons. The "protein type variant" of the storage material (Elleder 1978) displayed the highest degree of lipid-bound mannose accumulation, the GP component being extremely low or entirely absent. In the late infantile, infantile and Kufs variants studied in paraffin sections only, the GP component was detectable, too as in the case of the secondary neuronal LP in mucopolysaccharidoses and gangliosidoses. In the dog model of NCL lipid bound mannose clearly predominated, the GP component being concentrated in the cytoplasm and on the periphery od some storage granules. The nature of the GP component, a new finding of LP analysis, is discussed. The metabolic relationship between the two components is uncertain. Neither could be identified as the component resposible for autofluorescence.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adolescent; Adult; Animals; Ceroid; Child; Child, Preschool; Concanavalin A; Gangliosidoses; Humans; Lipofuscin; Mannose; Mucopolysaccharidoses; Neuronal Ceroid-Lipofuscinoses; Neurons; Olivary Nucleus; Pigments, Biological; Staining and Labeling

The ceroid-lipofuscinoses (CL) are a group of inherited diseases characterised by the accumulation, in brain, of autofluorescent storage cytosomes which have similar histochemical staining properties to lipofuscin, the neuronal wear and tear pigment of old-age brain. The storage cytosomes stain strongly with periodic acid-Schiff reagent (PAS), indicating the presence of carbohydrate. In brain from each childhood form of CL, concentrations of phosphorylated dolichol (Dol-P) are 10- to 20- fold higher than in age-matched controls. Brain Dol-P concentrations are also increased between 2 and 5- fold in several different lipidoses and in elderly subjects. Much of the Dol-P which accumulates is located within the storage cytosomes. Dol-P constitutes 2-3% of the dry weight of storage cytosomes from juvenile and late-infantile CL, and 0.3-0.7% of storage cytosomes from infantile CL, ovine CL and of lipofuscin isolated from old age brain. The bulk of the Dol-P in CL brain and in isolated storage cytosomes is present as dolichyl pyrophosphoryl oligosaccharides (Dol-PP-OS). The constitutions of the oligosaccharide moieties differ in the various forms of the disease. Histochemical analysis of frozen sections of unfixed brain after extraction by various lipid solvents indicates that the major part of the PAS positive intraneuronal material in CL brain and in old-age brain has the extraction properties of Dol-PP-OS. Carbohydrate represents 4-7% of the dry weight of CL storage cytosomes and of lipofuscin. The major monosaccharide components are mannose, N-acetyl glucosamine, glucose and galactose. Depending on the form of the disease studied, up to 40% of this material can be accounted for by Dol-PP-OS. Polyacrylamide gel electrophoresis of storage cytosomes followed by lectin blotting demonstrates several low molecular weight components which bind concanavalin A. These do not coelute with the major protein components and may well be Dol-PP-OS. We conclude that Dol-PP-OS are concentrated in storage cytosomes in CL and are one of their major glycoconjugate components.

Topics: Aging; Brain Chemistry; Concanavalin A; Dolichol Phosphates; Electrophoresis, Polyacrylamide Gel; Glycoconjugates; Humans; Lipofuscin; Microscopy, Electron; Monosaccharides; Neuronal Ceroid-Lipofuscinoses; Polyisoprenyl Phosphate Oligosaccharides; Protein Binding

Concanavalin A (Con A) binding to lipopigments (LPs) of the lipofuscin type was proved to be due to the high content of mannose. Two mannose bearing compounds could be recognized due to their different organic solvent solubility. One was best soluble in modified chloroform-methanol-water mixture (10:10:3) and corresponded most probably to the oligosaccharyl disphosphodolichol (oligo-PP-Dol) described to be significantly increased in LPs of inherited type. The second one, organic solvent insoluble corresponded to a glycoprotein (GP). The ratio of the two components varied. The deposition of the typical lipofuscin (age pigment) was dominated by the GP component. Its amount was greatest in neurolipofuscin (especially in the olivary nucleus) but very little in hepatocytic lipofuscin. In human neuronal ceroid lipofuscinoses (of early juvenile, and juvenile types) both components were found in large quantities in the storage granules of the affected neurons. The "protein type variant" of the storage material (Elleder, 1978) displayed the highest degree of lipid-bound mannose accumulation, the GP component being absent. In the late infantile, infantile and Kufs variants studied in paraffin sections only, the GP component was detectable, too as in the case of the secondary neuronal LP in mucopolysaccharidoses and gangliosidoses. In the canine model of NCL lipid bound mannose clearly predominated, the GP component being in low amount on average. Neither of the Con A reactive glycoconjugates could be identified as the component responsible for autofluorescence. However, both are most probably responsible for PAS positivity of lipofuscins. There were no detectable Con A reactive glycoconjugates in the histiocytic ceroid.

Topics: Animals; Ceroid; Child, Preschool; Concanavalin A; Dog Diseases; Dogs; Gangliosidoses; Histocytochemistry; Humans; Infant; Lipofuscin; Mucopolysaccharidoses; Neuronal Ceroid-Lipofuscinoses; Sheep; Sheep Diseases