Lectin histochemistry of lipofuscin and certain ceroid pigments

Abstract

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.

Cytological and Lectin Histochemical Characterization of Secretion Production and Secretion Composition in the Tubular Glands of the Canine Anal Sacs

“…In this way the presence of ceroid-type lipofuscin is demonstrated [Pearse, 1985;Yin, 1996;Schnell et al, 1999]. The finding is corroborated by the lectin histochemistry performed, because the secondary lysosomes showed strongly positive cytochemical reactions for ·-mannose [see Monserrat et al, 1995]. The latter aspect may be of interest concerning the cause of lipofuscinrelated autophagolysosome formation.…”

Characterization and Quenching of Autofluorescence in Piglet Testis Tissue and Cells

“…Fluorescent granules were also observed in Leydig cells in testes of mature crossbred boars [35]; however, to our knowledge autofluorescence has not been reported in neonatal piglet testes. It is important to note that autofluorescence with broad excitation and emission wavelengths is considered typical of lipofuscin and lipofuscin-like pigments [26], and quenching of such autofluorescence by lipid staining (e.g., SBB) was suggested to further indicate the lipofuscin origin of the autofluorescence [26, 30, 31, 36]. Therefore, the fact that the autofluorescence in the present study had a broad spectrum (425 to 700 nm with solid signal from 480 to 620 nm and was observable with widely used filters) and was quenchable with SBB supports the speculation that lipofuscin or lipofuscin-like pigments are mainly responsible for the autofluorescence in the piglet testes.…”

Pigments in Aging: An Overview

“…Because the chemical analysis of lipofuscin and ceroid pigments involves the laborious procedures of isolation and does not permit determination of the location of substances in different cells of a tissue or organ, pathologists generally prefer the in situ location of substances by histochemical means 28. We have explored by lectin histochemistry possible saccharide differences between in situ lipofuscin and diverse ceroid pigments 29. The lectin reactivities were determined in neurons and cardiac myocytes of old human subjects (74‐85 years) and rats (> 30 months), in the ceroid pigment of human aortic atheromas, as well as in the ceroid pigments that accumulate in the uteri of vitamin E‐deficient rats, in the livers of choline‐deficient rats, and in the crushed epididymal fat pad of rats.…”