Diversity of cell glycoconjugates shown histochemically: a perspective.

Abstract

IntroductionThe earliest histochemical methods for demonstrating carbohydratecontaining macromolecules served mainly to &rentiate these substances, as a general class, from the other macromolecular constituents in tissue sections: the proteins, nucleic acids, and lipids (93,137). A later stage in the development of this field aimed at distinguishing by histochemistry subclasses of carbohydratecontaining components, e.g., neutral and acidic constituents and subgroups of the acidic substances. The capacity to characterize complex carbohydrates in situ in tissue sections progressed subsequently with the use of carbohydrate-degrading enzymes to locate moieties possessing a specific carbohydrate linkage labile to the enzyme and of immunostaining to identlfy specific epitopes. An added dimension for analysis of glycoconjugate (GC) structure in situ followed the advent of labeled lectins which allow histochemical demonstration of terminal or internal sugars or of sugar sequences.This review attempts to put in perspective the status of carbohydrate histochemistry before and after introduction of the lectin approach. Progress in the development and application of non-lectin methods for light and electron microscopic localization has been reviewed (126,137,153,172,175,205,210,213,234) and will be covered here in summary form. A voluminous literature on lectin histochemistry and its use in a wide range of adult and embryonic tissues and pathological lesions at the light and electron microscopic level has also been reviewed extensively tinctive chemical structure in diverse sites of highly specialized biologica1 activity. Such an association implies relevance of the chemical nature of the GC to the function where it occurs. A number of examples of such concurrence will be described that point to possible participation of a specific GC in a particular biological function at a precise histological or cytological site. Pre-lectin Histochemistry of Complex CarbohydratesA large class of macromolecules in mammalian tissues differs from the other classes in possessing sugar residues. These carbohydratecontaining components are referred to in general as complex carbohydrates, a term that includes both polysaccharides, such as glycogen, and glycoconjugates (GCs), in which sugars are linked to non-carbohydrate moieties. Histochemical methods specific for visualizing GCs and differentiating them from proteins, nucleic acids, and lipids depended initially on their content of sugars with vicinal hydroxyls and of distinctive acidic moieties (26) (Figure 1; Eble 1). Thus, GCs which alone among the classes of macromolecules contain hexoses with vicinal hydroxyls were visualized selectively with the periodic acid-Schiff (PAS) procedure (93, 109). In addition, highly acidic sulfate esters and less acidic carboxyls of sialic acids and uronic acids in G C s were found to bind a variety of cationic dyes that did not react with less acidic dicarboxylic amino acids in proteins or with nucleic acids. Basic reagents commonly used included alcian bl...

Morphometric Features and Glycoconjugate Pattern of Rabbit Intestine are Affected by Particle Size of Pelleted Diets

“…However, the two experimental samples showed a different glycoconjugate pattern because oligosaccharides terminating Neu5AcGalb1,3GalNAc (KOH-sialidase-PNA) was observed in fine fed rabbits only and those terminating with GalNAca1,3(LFuca1,2)Galb1,3/ 4GlcNAcb1 (DBA staining) in coarse fed ones. These results suggest the presence in the brush border of O-and N-linked glycoconjugates because GalNAc residues are contained in many O-linked oligosaccharides containing GalNAc (Spicer and Schulte, 1992) and Con A binds to a range of N-linked glycans from high-Man (Goldstein and Hayes, 1978;Debray et al, 1981). The presence of DBA and Con A binding sites have been found in a previous lectin histochemistry study on rabbit duodenum (Zanuzzi et al, 2010).…”

“…The supranuclear positivity could indicate the presence of Golgi apparatus (Ross et al, 1989), because PNA binds many O-linked oligosaccharides containing GalNAc (Spicer and Schulte, 1992) and O-linked glycans are synthesized in the Golgi complex (Engelsberg et al, 2003). The epithelium lining the crypts of the distal colon showed a more complex glycoconjugate pattern than in the cecum.…”

“…Therefore, they are a useful tool to investigate glycans distribution as well as cell differentiation and maturation (Spicer and Schulte, 1992). Lectin histochemistry has been successfully used to evaluate in situ the composition of the oligosaccharides in the intestine mucosa (Etzler and Branstrator, 1979;Gelberg et al, 1992;Falk et al, 1994Falk et al, , 1995Schumacher, 1995a, 2001;Jelínek, 1996;Sharma et al, 1997;Brunsgaard, 1998;Pedini et al, 2001;Zanuzzi et al, 2010).…”

Lectin histochemical aspects of the ovarian lamellae epithelium of Genypterus blacodes (Schneider, 1801)

“…In particular, the glycocalyx of the epithelium of the ovarian lamellae of G. blacodes strongly reacted with Con A, which indicates the presence of terminal, α-manosyl residues. Con-A, like other Man-binding lectins, was recently used to identify GCs containing N-linked oligosaccharides, since O-linked oligosaccharides contain less than 1% Man (Spicer and Schulte 1992). Mannose is speciϐic to serous cells in human bronchioles (Rogers et al 1993).…”

A lectin histochemical study on carbohydrate moieties of the gonadotropin-like substance in the epithelial cells of Hatschek's pit ofBranchiostoma belcheri

“…The binding pattern of HPA, WGA, Con A and UEA I in Hatschek's pit is similar to that of LPA, giving a strong or moderate binding reaction. It is k n o w n that HPA recognizes N-acetyl-D-galactosamine (Hammarstr6m et al, 1977;Debray et al, 1981); WGA recognizes N-acetyl-D-glucosamine (Spicer & Schulte, 1992;Araujo et al, 1993); Con A recognizes D-mannose (Goldstein & Poretz, 1986); and UEA I recognizes L-fucose (Sugii et al, 1982;Araujo et al, 1993). This observation indicates, in addition to sialic acid, the presence of other carbohydrates in B r a n c h i o s t o m a ' s gonadotropin, including D-galactosamine, D-glucosamine, D-mannose and L-fucose.…”