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

THE LYSOSOMAL STORAGE DISEASE GM2 GANGLIOSIDOSIS IN CAPTIVE BANDED MONGOOSE SIBLINGS ( MUNGOS MUNGO)

  This study reports the occurrence of the lysosomal storage disease GM2 gangliosidosis (Sandhoff disease) in two 11-mo-old captive-bred, male and female mongoose siblings ( Mungos mungo). The clinical signs and the pathological findings reported here were similar to those reported in other mammalian species. Light microscopy revealed an accumulation of stored material in neurons and macrophages accompanied by a significant neuronal degeneration (swelling of neuronal soma, loss of Nissl substance, and neuronal loss) and gliosis. Electron microscopy of brain tissue identified the stored material as membrane-bound multilamellar bodies. An almost complete lack of total hexosaminidase activity in serum suggested a defect in the HEXB gene (Sandhoff disease in humans). High-performance thin-layer chromatography and mass spectrometry confirmed the accumulation of GM2 ganglioside in brain and kidney tissue, and the lectin staining pattern of the brain tissue further corroborated the diagnosis of a Sandhoff-type lysosomal storage disease.

Clinical and Morphologic Changes in Ewes and Fetuses Poisoned by Ipomoea Carnea Subspecies Fistulosa

Intoxication with Ipomoea carnea has been reported in goats, sheep, and cattle in tropical regions worldwide. The disease has been characterized only in goats; therefore, the present study was conducted in sheep. Nine animals were fed feed rations that contained 3 different concentrations of Ipomoea carnea subsp. fistulosa. Individual intake varied between 10.5 and 135.2 g of fresh plant per kilogram of body weight (BW) per day. Animals first showed clinical signs between day 43 and day 63. The maximum survival time was 133 days. Sheep presented with weight loss and neurologic abnormalities. Neurologic signs were dominated by marked depression, abnormal behavior, and musculoskeletal weakness, with poorly defined motor and proprioceptive deficits. In mature animals, cytoplasmic vacuolation, consistent with accumulation of secondary lysosomes, affected neurons, astrocytes, exocrine pancreatic acinar epithelia, hepatocytes and Kupffer cells, renal tubular epithelia, thyroid follicular epithelia, cortical adrenal epithelia, endothelia and perivascular cells, and macrophages in lymph nodes and spleen. In the central nervous system, there was axonal degeneration and astrogliosis. Abortion was observed as early as day 22 of the trial. In fetal tissues and placenta of chronically poisoned ewes, cytoplasmic vacuolation was histologically detected in neurons, exocrine pancreatic acinar epithelia, hepatocytes, renal tubular epithelia, and thyroid follicular epithelia. All the sheep developed a glycoprotein storage disease, with lysosomal accumulation of N-glycosidically linked oligosaccharides, which was indistinguishable from that induced by the alkaloid swainsonine alone.

Animal models of human cerebellar ataxias: a cornerstone for the therapies of the twenty-first century

Cerebellar ataxias represent a group of disabling neurological disorders. Our understanding of the pathogenesis of cerebellar ataxias is continuously expanding. A considerable number of laboratory animals with neurological mutations have been reported and numerous relevant animal models mimicking the phenotype of cerebellar ataxias are becoming available. These models greatly help dissecting the numerous mechanisms of cerebellar dysfunction, a major step for the assessment of therapeutics targeting a given deleterious pathway and for the screening of old or newly synthesized chemical compounds. Nevertheless, differences between animal models and human disorders should not be overlooked and difficulties in terms of characterization should not be occulted. The identification of the mutations of many hereditary ataxias, the development of valuable animal models, and the recent identifications of the molecular mechanisms underlying cerebellar disorders represent a combination of key factors for the development of anti-ataxic innovative therapies. It is anticipated that the twenty-first century will be the century of effective therapies in the field of cerebellar ataxias. The animal models are a cornerstone to reach this goal.

Differential lectin histochemical studies on lipofuscin (age-pigment) and on selected ceroid pigments

The persistent indiscriminate use of the term lipofuscin for the pigments encountered in pathological conditions, and which should be most properly termed ceroid pigments, is still creating unnecessary conceptual and nomenclature problems, and a great deal of confusion. While both the age-dependent lipofuscin and the pathologically formed ceroid pigments have somewhat similar physical and histochemical properties, sufficient differences to properly identify these two types of pigments are presented in this communication. In addition, because little is known on the saccharide components of lipofuscin and ceroid pigments in situ, we have in recent years explored the lectin binding characteristics of lipofuscin in human and rats, as well as in diverse ceroid pigments experimentally induced in rats. Our lectin histochemical results showed qualitative and quantitative differences in the saccharide composition between human cerebral neurolipofuscin and the intra and extracellular ceroid pigment of human atheromas, as well as, between rat lipofuscin and the ceroid pigments induced in these animals.

GM1 gangliosidosis in shiba dogs

A six-month-old shiba dog with a one-month history of progressive motor dysfunction showed clinical signs of a cerebellar disorder, including ataxia, dysmetria and intention tremor of the head. Histopathological and ultrastructural studies revealed distended neurons packed with membranous cytoplasmic bodies throughout the central nervous system. The activities of lysosomal acid beta-galactosidase in its leucocytes and liver were less than 2 per cent of the control levels, and the compound accumulated in the brain was identified as GM1 ganglioside. A sibling which died immediately after birth was shown to have a beta-galactosidase deficiency in the brain and visceral organs. A family study revealed that the sire and dam of the probands were heterozygotes with approximately half of the normal level of beta-galactosidase activity, suggesting an autosomal recessive pattern of inheritance.

The pigment of melanosis coli: a lectin histochemical study

BACKGROUND

The compositional nature of the pigment of melanosis coli is essentially unknown. Previous histochemical studies suggested that this pigment has certain similarities with lipofuscin (i.e., age-dependent pigment) and ceroids (i.e., pathologically derived pigments) and that it may contain, therefore, polymerized glycolipids and glycoproteins. However, the saccharide composition of this pigment was never explored by lectin histochemical procedures, which was the main object of this study.

METHODS

Colonoscopic biopsy specimens from eight patients with melanosis coli and from three normal control subjects were studied by fluorescent microscopy and by standard and lectin histochemistry. The number of apoptoses in the lining colonic epithelium was also evaluated histologically.

RESULTS

Apoptotic bodies were significantly more numerous in patients with melanosis coil than in control subjects. The pigment that accumulates in macrophages of the lamina propia showed autofluorescence, sudanophilia, acid-fastness, and positiveness to PAS and Schmorl's reactions, all of which are common to lipofuscin and ceroids, plus an intense argentaffin reaction abolished by bleaching, indicative of a melanic substance. Lectin histochemistry showed, in decreasing order of frequency, the presence of alpha-D-mannose, sialic acid, beta-D-galactose (lactose), gal-beta-(1-3)acetyl-galactosamine, alpha-D-galactose, and alpha-L-fucose, but no terminal alpha-D-acetyl-galactosaminyl residues.

CONCLUSIONS

The significant increase of apoptotic bodies in the lining colonic epithelium indicated that this type of cell death is not due to the natural programmed cell renewal, but to the action of laxatives. Because the autofluorescent pigment of melanosis coli contains melanin (as well as glycoconjugates) and is not dependent on age but on the use of anthranoid laxatives, it should be categorized as a "melanized ceroid." The lectin affinities of this pigment indicated that it contains a substantial number of saccharide residues almost similar to those found in the ceroid pigment of human aortic atheromas. These findings and considerations on the metabolism and pharmacokinetics of anthranoids suggested that the apoptotic epithelial cells, rather than the laxatives, may be the source of the pigment saccharides, whereas the precursors of the melanic substance may be derived from the anthranoids.

Biochemical basis of lipofuscin, ceroid, and age pigment-like fluorophores

Serious studies of the formation mechanisms of age-related pigments and their possible cellular influence have been hampered for a long time by discrepancies and controversies over the definition, fluorescence emission, origin, and composition of these pigments. This review discusses several critical controversies in this field and lay special emphasis on the cellular and biochemical reactions related to the formation mechanisms of lipofuscin, ceroid, advanced glycation end-products (AGEs), and age pigment like fluorophores (APFs). Various amino compounds and their reaction with secondary aldehydic products of oxygen free radical-induced oxidation, particularly lipid peroxidation, are important sources of the fluorophores of ceroid/lipofuscin, which progressively accumulate as a result of phagocytosis and autophagocytosis of modified biomaterials within secondary lysosomes of postmitotic and other cells. Lipofuscin is the classical age pigment of postmitotic cells, while ceroid accumulates due to pathologic and experimental processes. There are good reasons to consider both ceroid and lipofuscin as materials of the same principal origin. The age-related intracellular fluorophores of retinal pigment epithelium (RPE) seems to represent a special class of lipofuscin, which partly contains derivatives of retinoids and carotenoids. Saccharide-originated fluorophores, principally AGEs formed during glycation/Maillard reactions, may be mainly responsible for the extracellular fluorescence of long-lived proteins, such as collagen, elastin, and lens crystalline. Although lipofuscin, ceroid, AGEs, and APFs can be produced from different types of biological materials due to different side reactions of essential biology, the crosslinking of carbonyl-amino compounds is recognized as a common process during their formation.

Fluorophore-assisted carbohydrate electrophoresis technology and applications

Carbohydrates, in particular the complex carbohydrates conjugated to proteins and lipids, have important functions in a variety of biological systems. Their isolation and structural determination--prerequisites for elucidation of their biological functions--have been technical challenges for many decades. Almost all available chromatographic and electrophoretic methods as well as NMR and MS have been applied to carbohydrate analysis but none has proved satisfactory in terms of simplicity, sensitivity, reproducibility, cost and requirement for materials. Recently, a technique called fluorophore-assisted carbohydrate electrophoresis was developed which is very promising. It separates fluorescently-labeled carbohydrates on polyacrylamide gels and uses a charge-coupled device camera to detect and quantitate the products. This review describes the principles of the method and its applications to several aspects of research on carbohydrate-containing biological biomolecules.

Lectin histochemistry of lipofuscin and certain ceroid pigments

Little is known at present about the saccharide components of lipofuscin (age pigment) and ceroid pigments in situ. The purpose of this study was, therefore, to study in detail the lectin reactivities of lipofuscin in neurons and cardiac myocytes of old humans and rats. In addition, those of diverse ceroid pigments found in human aortic atheromas, in the livers of choline-deficient rats, in the uteri of vitamin E-deficient rats and in the crushed epididymal fat pad of rats, are included. Cryostat and deparaffinized sections from all these tissues were either extracted with a solvent mixture of chloroform-methanol-water (10:10:3, v/v) and incubated with 7 different biotinylated lectins or left untreated. Delipidation was done in order to study whether it was possible to discriminate between the saccharide moieties of glycolipids and glycoproteins of lipofuscin and ceroid pigments in situ. Other similarly treated sections were used to study the autofluorescence, sudanophilia, acid-fastness and reactivity to PAS. The frequency and intensity of lectin binding and standard histochemical properties of all the pigments were evaluated semi-quantitatively and blind. The results indicated that mannose was in general the most consistently detected sugar residue in lipofuscin granules of humans and rats, and that this pigment may also contain acetylglucosamine, acetylgalactosamine, sialic acid, galactose and fucose. However, notable differences were found not only in the lipofuscin saccharide components of different cell types of humans and rats, but also in those in the same type of cells in both species. Although mannose was not detected in the hepatic ceroid of choline-deficient rats, this saccharide moiety was almost always present in the other ceroid pigments. Each of the ceroids also contained other types of saccharides although the frequency of the latter varied between different ceroid pigments. While lipofuscin and each of the ceroid pigments showed somewhat different lectin binding patterns, the variability in the frequency of reactivity to lectins suggests that these patterns may not be permanent but transient. In this sense, it appears that lectin histochemistry may not allow these pigments to be differentiated. Furthermore, the extractive procedures used in this study did not enable us to determine whether the saccharides detected in the pigments in situ corresponded to glycolipids or glycoproteins.

Lectin histochemistry of infantile lysosomal storage disease associated with osteopetrosis

In infantile lysosomal storage disease associated with osteopetrosis the nature of the enzyme deficiency as well as the type of material accumulated are both unknown. We used lectin histochemistry to characterize the storage material of previously reported cases. Using paraffin sections neurons stained positively with Luxol fast blue (LFB), periodic acid-Schiff (PAS), Concanavalia ensiformis agglutinin, Datura stramonium agglutinin, Griffonia simplicifolia-I, Lens culinaris agglutinin, Ricinus communis agglutinin-I, succinylated wheat germ agglutinin and wheat germ agglutinin, indicating an accumulation of fucosylated N-glycosidically linked oligosaccharides containing beta- and alpha-galactosyl residues and compounds containing N-acetyllactosamine. Reticuloendothelial cells in liver and in spleen did not stain with LFB, but did stain with PAS and the above lectins. These results indicate that there is storage of both carbohydrates and lipids in neurons, and stored carbohydrates with similar residues in reticuloendothelial cells in this disease, where the primary defect is still unknown.

Storage of glycoprotein in NCTR-Balb/C mouse. Lectin histochemistry, and biochemical studies

A strain of Balb/C mice carrying a lysosomal storage disorder exhibits metabolic and phenotypic abnormalities similar to patients with sphingomyelin-cholesterol lipidoses type II (i.e., Niemann-Pick C and D). Their foamy cells, which belong to the reticuloendothelial system, stained intensely by periodate-Schiff (PAS) reagent and were resistant to predigestion with diastase. To identify the chemical nature of the PAS-positive storage material, we applied lectin histochemistry and biochemical methods. Paraffin embedded sections, and delipidated frozen tissue sections, were treated with biotinylated lectins and localized with avidin-biotin-peroxidase complex. Araldite-embedded semithin sections were incubated with biotinylated lectins followed by avidin-gold and were enhanced with silver. By both histochemical methods the affected foamy cells stained positively as follows: Concanavalia ensiformis agglutinin, Datura stramonium agglutinin, Griffonia simplicifolia-I, Lens culinaris agglutinin, peanut agglutinin, Ricinus communis agglutinin-I, wheat germ agglutinin (WGA), and succinylated-WGA. Biochemical analysis of liver extracts complemented the histochemical data and demonstrated accumulation of glycoproteins containing polylactosaminoglycans in affected mice. Our findings indicate that the storage material in NCTR-Balb/C mice is heterogeneous. The lipids that are extracted by organic solvents during the histologic preparations mask the occurrence of polylactosaminoglycan containing glycoproteins in native frozen sections.