Lectin histochemistry of gangliosidosis. II. Neurovisceral tissues from patients with Sandhoff's disease

Astrocytes and lysosomal storage diseases

Lysosomal storage diseases (LSDs) encompass a wide range of disorders characterized by inborn errors of lysosomal function. The majority of LSDs result from genetic defects in lysosomal enzymes, although some arise from mutations in lysosomal proteins that lack known enzymatic activity. Neuropathological abnormalities are a feature of several LSDs and when severe, represent an important determinant in disease outcome. Glial dysfunction, particularly in astrocytes, is also observed in numerous LSDs and has been suggested to impact neurodegeneration. This review will discuss the potential role of astrocytes in LSDs and highlight the possibility of targeting glia as a beneficial strategy to counteract the neuropathology associated with LSDs.

Application of lectin histochemistry and carbohydrate analysis to the characterization of lysosomal storage diseases

In lysosomal storage diseases that involve a defect in the catabolism of glycoconjugates, lectin histochemistry adds a new dimension to the characterization of stored carbohydrates as it identifies sugar residues in situ in the affected cells and, thus, determines which cell types are affected by storage. It may be combined with chemical and biochemical analysis by h.p.l.c. The present review summarizes recent results for a variety of storage diseases and presents new data for GM1-gangliosidosis.

Lectin histochemical study of lipopigments: results with concanavalin A

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.

Lectin histochemical study of lipopigments with special regard to neuronal ceroid-lipofuscinosis. Results with concanavalin A

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)

Lectin histochemistry of human gliomas

Formalin-fixed and paraffin-embedded specimens of 24 human gliomas were examined histochemically with five lectins; concanavalin A (Con A), wheat germ agglutinin (WGA), Ricinus communis agglutinin 1 (RCA-1), peanut agglutinin (PNA), and Ulex europaeus agglutinin 1 (UEA-1). Although the staining intensity with lectins was variable, tumor cells in five astrocytomas, three oligodendrogliomas, six ependymomas, and one gliosarcoma, were generally positive for Con A, WGA, and RCA-1, and negative for PNA and UEA-1, whereas those in nine glioblastomas were usually positive for Con A and WGA and negative for RCA-1 and PNA as well as UEA-1. The malignancy in neoplastic astrocytes was correlated with the decrease in binding with lectins, especially RCA-1. Blood vessels, particularly the endothelial layers, in all gliomas were stained intensely with all lectins used. Macrophages showed two staining features with lectins; stippled and granular. The former macrophages were positive for Con A, WGA, RCA-1, and PNA, and negative for UEA-1, whereas the latter macrophages were positive for all lectins used. Thus, the staining characteristics with lectins of macrophages were different from those of any glioma cells and very useful for identification of macrophages in gliomas.

Lectin histochemistry of brains from a murine mutant carrying a storage disorder

A strain of Balb/c mice with neurovisceral storage disorder exhibits metabolic and phenotypic manifestations similar to those found in Niemann-Pick type C and D patients. The storage material in the brain reacted positively with periodate-Schiff reagent. To identify the chemical nature of the storage material we applied lectin histochemistry on paraffin-embedded and frozen sections, using biotinylated lectins and avidin-biotin-peroxidase complex. Major abnormalities were noted in the neurons and glia cells. Swollen neurons were stained heavily by Con A and S-WGA, whereas glia cells, mainly astrocytes, which were abundant both in the cerebrum and cerebellum, were positive to RCA-I, GS-I, PNA, S-WGA and WGA. The myelin tracts reacted with PNA, SBA and RCA-I but to a lesser extent in affected animals when compared to normals. Frozen brain sections stained positively only after extraction with chloroform methanol prior to the lectin treatment and revealed a lectin binding pattern similar to that of the paraffin-embedded preparations. The data presented here show that the stored glucoconjugates in the neurons are of a different chemical composition than those found in glia cells. Since only paraffin embedded sections or lipid extracted frozen sections reacted with the lectins, we suggest that the stored glucoconjugates are glycoproteins or oligosaccharides rather than glycolipids.