Lectin binding sites in the human gallbladder and cystic duct

Summary A battery of 18 fluorescein isothiocyanate (FITC) labeled lectins was used to histochemically define the features of epithelial cells in the body, neck and the cystic duct of the human gallbladder. Surface epithelium in all three anatomic locations reacted with all lectins, either diffusely or focally, except for lectin type I from Griffonia simplicifolia and type II from Ulex europaeus. No quantitative differences were noted except for the tendency of some lectins to bind more often to the neck and cystic duct epithelium rather than the body and vice versa. In the body the surface epithelium did not differe from cells lining the crypts. On the other hand, glands of the neck and the cystic duct were essentially indistinguishable one from another but differed from the overlying surface epithelium in so far as they reacted with some lectins which were unreactive with surface epithelium and vice versa. Considerable case to case variation in the expression of lectin binding sites in each of three anatomic areas was noted. No consistent differences were noticed between gallbladders removed for cholecystitis — cholelithiasis and those removed for other incidental reasons. We conclude that all epithelial cells in the cholecysto-biliary tract are rich on glyconjugates but the pattern of expression varies depending on the anatomical location and the influence of poorly understood individual determinants.     

Lectin histochemistry of mouse vagina during the estrous cycle

Estrous cycle-related histochemical changes in the vaginal epithelium of sexually mature female mice were studied with 30 fluorescein isothiocyanate (FITC)-labeled lectins. On the basis of the staining pattern the lectins were divided into five groups: I, seventeen lectins that reacted with mucinous surface layer of proestrus. This group comprised two subgroups: Ia, seven lectins that reacted exclusively with the mucinous layer, and Ib, ten lectins that reacted with mucinous cells and the underlying squamous epithelium of proestrus; II, two lectins that reacted with squamous epithelium of proestrus only but were unreactive with mucinous cells; III, three lectins that reacted in a phase-specific manner with squamous epithelium; IV, six lectins that showed increased luminal surface reactivity in diestrus and/or metestrus; and V, eleven lectins that were unreactive with vaginal epithelium. These data indicate that the cyclic changes in the morphology of the vaginal epithelium are accompanied by distinct lectin reactivity patterns.     

Characterization of Cell Surface Lectin-binding Patterns of Human Airway Epithelium

Glycosylated structures on the cell surface have a role in cell adhesion, migration, and proliferation. Repair of the airway epithelium after injury requires each of these processes, but the normal cell surface glycosylation of non-mucin producing airway epithelial cells is unknown. We examined cell surface glycosylation in human airway epithelial cells in tissue sections and in human airway epithelial cell lines in culture. Thirty-eight lectin probes were used to determine specific carbohydrate residues by lectin-histochemistry. Galactose or galactosamine-specific lectins labeled basal epithelial cells, lectins specific for several different carbohydrate structures bound columnar epithelial cells, and fucose-specific lectins labeled all airway epithelial cells. The epithelial cell lines 1HAEo– and 16HBE14o– bound lectins that were specific to basal epithelial cells. Flow cytometry of these cell lines with selected lectins demonstrated that lectin binding was to cell surface carbohydrates, and revealed possible hidden tissue antigens on dispersed cultured cells. We demonstrate specific lectin-binding patterns on the surface of normal human airway epithelial cells. The expression of specific carbohydrate residues may be useful to type epithelial cells and as a tool to examine cell events involved in epithelial repair.     

The mink as an animal model for Pseudomonas aeruginosa adhesion: binding of the bacterial lectins (PA-IL and PA-IIL) to neoglycoproteins and to sections of pancreas and lung tissues from healthy mink

Lung infection with Pseudomonas aeruginosa, leading to chronic lung disease with impaired function, is the major course of morbidity and mortality among cystic fibrosis patients. The bacterium produces two lectins that bind to alpha-D-galactose (PA-IL) and L-fucose (PA-IIL), respectively, and lectin-carbohydrate interactions may be involved in microbial pathogenicity by creating bacterial adherence to epithelial and endothelial cells. An ideal animal model for P. aeruginosa infection has until now not been established, but the mink seems to be the only animal that has been reported to develop spontaneous P. aeruginosa infections in the airways. Since cystic fibrosis also severely may affect pancreatic function, we incubated sections from mink lungs and pancreas with a medium containing Pseudomonas lectins in order to detect in situ binding of the bacterial lectins. In the lungs, both lectins adhered to seromucinous glands located in the submucosa of the larger bronchi. Additionally, PA-IL reacted with the capillaries in the alveolar walls and with the small blood vessels forming the vasa vasorum around the larger vessels, while PA-IIL marked the goblet cells in the bronchial surface epithelium. In the pancreas, both lectins bound to the epithelium in the excretory ducts, and additionally, PA-IL strongly stained the pancreatic capillaries while PA-IIL staining was noticed in the apical part of acinar cells in the exocrine part of the gland while no lectin reaction could be recorded in the endocrine cells. Judging from the results in the present paper the mink should be considered a suitable model to study P. aeruginosa adherence.     

DIFFERENTIAL LOCALIZATION OF CELL SURFACE AND SECRETORY COMPONENTS IN RAT INTESTINAL EPITHELIUM BY USE OF LECTINS

Sections through various levels of small intestine from adult male rats were examined by fluorescence microscopy after treatment with fluorescein isothiocyanate-labeled lectins from Dolichos biflorus, Lotus tetragonolobus, Ricinus communis, and Triticum vulgare (wheat germ). The latter three lectins reacted with the microvillar portion of the epithelial cells lining the crypts and villi in sections of intestine adjacent to the pylorus. This pattern of reactivity was sharply altered along the first 15 cm of intestine so that in sections distal to this point the luminal surfaces of only those epithelial cells in the crypts and at the base of the villi reacted with the L. tetragonolobus and R. communis lectins, whereas the wheat germ lectin reacted with the surfaces of the cells lining the villi. In sections from the distal end of the small intestine, all three lectins reacted with the surfaces of cells only at the base of the villi and in the crypts. These results show a difference in surface components in cells at various portions on the villi and the dependence of these differences on the region of intestine. The D. biflorus lectin reacted with approximately 25% of the goblet cells at each level of intestine studied whereas the reactivities of the goblet cells with the other three lectins were dependent upon the region of intestine.     

Heterogeneity of apical glycoconjugates in kidney collecting ducts: Further studies using simultaneous detection of lectin binding sites and immunocytochemical detection of key transport enzymes

Summary In the search for a functional role for the polarized glycoconjugates of rat collecting duct epithelial cells, the relation between binding of various lectins and expression of cellular transport enzyme profile of the cells was studied. For this purpose, principal and intercalated cells of rat kidney collecting duct were identified by morphological criteria and by their immunocytochemically determined content of (Na⁺+K⁺)-ATPase and carbonic anhydrase (CA II), respectively. VariousN-acetylgalactosamine-specific lectins such as those fromHelix pomatia andMaclura pomifera revealed heterogeneity among both principal and intercalated cells, whereas -N-acetylgalactosa nine-specific lectin fromDolichos biflorus andVicia villosa bound preferentially to principal cells. Still another lectin fromArachis hypogaea reacted with most collecting duct cells in the cortex and outer medulla, but only with a subpopulation of cells in the inner medulla. Interestingly, some lectins reacted exclusively with the apical aspect of the collecting duct epithelial cells, whereas others revealed both an apical and basolateral distribution of lectin reactive glycoconjugates. The results thus show subtle differences in the glycocalyx structure of principal and intercalated cells and differences in the intracellular polarization of glycoconjugates of these cells. Thus, lectins may be useful tools in the study of the molecular mechanisms which establish and maintain the polarized functions of principal and intercalated cells.     

Lectin binding in the anterior segment of the bovine eye

Summary Eleven different fluorescent lectin-conjugates were used to reveal the location of carbohydrate residues in frozen sections of the anterior segment of bovine eyes. The lectins were specific for the following five major carbohydrate groups: (1) glucose/mannose group (Concanavalin A (Con A)); (2)N-acetylglucosamine group (wheat germ agglutinin (WGA)); (3) galactose/N-acetylgalactosamine group (Dolichos biflorus agglutinin (DBA),Helix pomatia agglutinin (HPA),Helix aspersa agglutinin (HAA),Psophocarpus tetragonolobus agglutinin (PTA),Griffonia simplicifolia agglutinin-I-B₄ (GSA-I-B₄),Artocarpus integrifolia agglutinin (JAC), peanut agglutinin (PNA) andRicinus communis agglutinin (RCA-I)); (4)l-fucose group (Ukex europaeus agglutinin (UEA-I)); (5) sialic acid group (wheat germ agglutinin (WGA)). All the studied lectins except UEA-I reacted widely with different structures and the results suggest that there are distinct patterns of expression of carbohydrate residues in the anterior segment of the bovine eye. UEA-I bound only to epithelial structures. Some of the lectins reacted very intensely with apical cell surfaces of conjunctival and corneal epithelia suggesting a different glycosylation at the glycocalyx of the epithelia. Also, the binding patterns of conjunctival and corneal epithelia differed with some of the lectins: PNA and RCA-I did not bind at all, and GSA-I-B₄ bound only very weakly to the epithelium of the cornea, whereas they bound to the epithelium of the conjunctiva. In addition, HPA, HAA, PNA and WGA did not bind to the corneal basement membrane, but bound to the conjunctiva and vascular basement membranes. This suggests that corneal basement membrane is somehow different from other basement membranes. Lectins with the same carbohydrate specificity (DBA, HPA, HAA and PTA) reacted with the sections almost identically, but some differences were noticed: DBA did not bind to the basement membrane of the conjunctiva and the sclera and did bind to the basement membrane of the cornea, whereas other lectins with same carbohydrate specificities reacted vice versa. Also, the binding of PTA to the trabecular meshwork was negligible, whereas other lectins with the same carbohydrate specificities reacted with the trabecular meshwork. GSA-I-B₄ reacted avidly with the endothelium of blood vessels and did not bind to the stroma, so that it made blood vessels very prominent and it might be used as an endothelial marker. This lectin also reacted avidly with the corneal endothelium. Therefore, GSA-I-B₄ appears to be a specific marker in bovine tissues for both blood vessel and corneal endothelium cells.     

Changes in lectin-binding pattern in the digestive tract of Xenopus laevis during metamorphosis. I. Gastric region.

The distribution of structural and secretory glycoconjugates in the gastric region of metamorphosing Xenopus laevis was studied by the avidin-biotin-peroxidase (ABC) histochemical staining method using seven lectins (concanavalin A, Con A; Dolichos biflorus agglutinin, DBA; peanut agglutinin, PNA; Ricinus communis agglutinin I, RCA-I; soybean agglutinin, SBA; Ulex europeus agglutinin I, UEA-I; and wheat germ agglutinin, WGA). Throughout the larval period to stage 60, the epithelium consisting of surface cells and gland cells was stained in various patterns with all lectins examined, whereas the thin layer of connective tissue was positive only for RCA-I. At the beginning of metamorphic climax, the connective tissue became stained with Con A, SBA, and WGA, and its staining pattern varied with different lectins. The region just beneath the surface cells was strongly stained only with RCA-I. With the progression of development, both the epithelium and the connective tissue gradually changed their staining patterns. The surface cells, the gland cells, and the connective tissue conspicuously changed their staining patterns, respectively, for Con A and WGA; for Con A, PNA, RCA-I, SBA, and WGA; and for Con A, RCA-I, and WGA. At the completion of metamorphosis (stage 66), mucous neck cells became clearly identifiable in the epithelium, and their cytoplasm was strongly stained with DBA, PNA, RCA-I, and SBA. These results indicate that lectin histochemistry can provide good criteria for distinguishing among three epithelial cell types, namely, surface cells, gland cells, and mucous neck cells, and between adult and larval cells of each type.     

Anatomic distribution of lectin-binding sites in mouse testis and epididymis

Abstract. Testis and epididymis of sexually mature mice were studied histochemically using 25 fluorescein-isothiocyanate-labeled lectins. Several lectin-specific binding patterns were recognized. Thus, HAA, HPA, GSA-I, and UEA-I1 reacted only with spermatozoa. PNA, GSA-11, SBA, VVA, BPA, RCA-I, and RCA-I1 reacted with spermatozoa and spermatocytes. WGA, PEA, LCA, and MPA reacted with spermatogonia, spermatocytes, and spematozoa in increasing order of intensity. ConA, SUC. ConA, LAA, STA, LTA, LPA, PHA-E, PHA-L, IJEA-I, and LBA reacted with all spermatogenic cells with equal intensity. In the epididymis, 12 lectins reacted uniformly with the epithelial cells lining all segments of this organ. One lectin (VVA) did not react with epididymal lining cells. The remaining 12 lectins reacted in a specific manner with portions of the head, body, or tail, thus selectively outlining different portions of the epididymis. RCA-I and RCA-I1 selectively accentuated the so-called halo cells of the epididymis. These findings provide a detailed map of lectin-binding sites in the mouse testis and epididymis and show that certain lectins can be used as specific markers for spermatogenic cells and segments of the epididymis.     

Anatomic distribution of lectin-binding sites in mouse testis and epididymis

Testis and epididymis of sexually mature mice were studied histochemically using 25 fluorescein-isothiocyanate-labeled lectins. Several lectin-specific binding patterns were recognized. Thus, HAA, HPA, GSA-I, and UEA-II reacted only with spermatozoa. PNA, GSA-II, SBA, VVA, BPA, RCA-I, and RCA-II reacted with spermatozoa and spermatocytes. WGA, PEA, LCA, and MPA reacted with spermatogonia, spermatocytes, and spermatozoa in increasing order of intensity. ConA, Suc. ConA, LAA, STA, LTA, LPA, PHA-E, PHA-L, UEA-I, and LBA reacted with all spermatogenic cells with equal intensity. In the epididymis, 12 lectins reacted uniformly with the epithelial cells lining all segments of this organ. One lectin (VVA) did not react with epididymal lining cells. The remaining 12 lectins reacted in a specific manner with portions of the head, body, or tail, thus selectively outlining different portions of the epididymis. RCA-I and RCA-II selectively accentuated the so-called halo cells of the epididymis. These findings provide a detailed map of lectin-binding sites in the mouse testis and epididymis and show that certain lectins can be used as specific markers for spermatogenic cells and segments of the epididymis.     

Immuno- and lectin histochemistry of epithelial subtypes and their changes in a radiation-induced lung fibrosis model of the mini pig

Cell types of lung epithelia of mini pigs have been studied using a panel of monoclonal and polyclonal antibodies against cytokeratins (CKs) and vimentin and three lectins before and after radiation-induced fibrosis. In normal tissues, CK18 specific antibodies reacted above all with type II alveolar epithelial cells, while CK7 and pan CK-specific antibodies stained the whole alveolar epithelium. In bronchial epithelial cells, CKs 7, 8, 18 and focally CKs 4 and 13 as well as vimentin were found. Cell specificity of the CK pattern was confirmed by double label immunofluorescence using type II cell-specific Maclura pomifera (MPA) lectin, type I cell specific Lycopersicon esculentum (LEA) lectin and capillary endothelium-binding Dolichos biflorus (DBA) lectin. In experimental pulmonary fibrosis, enhanced coexpression of CK and vimentin was observed in bronchial epithelium. Subtypes of alveolar epithelial cells were no longer easily distinguishable. CK18 was found to be expressed in the entire alveolar epithelium. The gradual loss of the normal alveolar epithelial marker, as seen by the binding of MPA to type I-like cells, of LEA to type II-like cells and the partial loss of MPA-binding to type II cells, was paralleled by the appearance of CK4, typical for squamous epithelia, and the occurrence of DBA-binding in epithelial cells. Implications of these results for general concepts of intermediate filament protein expression and lectin binding in the fibrotic process are discussed.     

Pregnancy-related changes in the human endometrium revealed by lectin histochemistry

The binding of 22 fluorescein isothiocyanate (FITC) conjugated lectins to human proliferative phase and pregnant endometrium was studied histochemically. Only the lectin from Bauhinia purpurea (BPA) reacted exclusively with the epithelial cells. All the others reacted to a certain extent with glandular and/or stromal cells. Lectins from soybean (SBA), and Vicia villosa seeds (VVA) reacted with endometrial glands of pregnancy but not with the glands of the proliferative endometrium. In the proliferative endometrium SBA reacted only with cells of the surface endometrium. Lectin from peanuts (PNA) reacted only with some glands in the proliferative endometrium but was unreactive with others. In pregnant endometrium PNA reacted with all glands. Lectins from lentils (LCA) and red kidney beans (PHA-E and PHA-L) reacted with endometrial glands of the proliferative phase but not with the glands from pregnant endometrium. We thus show that FITC labeled lectins define specific carbohydrate moieties selectively expressed on either proliferative phase or pregnant endometrial glands.     

Lectin histochemistry of normal human gastric mucosa

Information about the saccharides expressed in gastric mucosa is mostly limited to the glycan content of gastric mucins and there are only a few studies of the glycoprofiling of the constituent cells and their components. Knowledge of the glycan expression of normal gastric mucosa is necessary for the interpretation of the significance of changes of expression in disease. lectin histochemical study of normal human gastric (body) mucosa was performed using 27 lectins chosen to probe for a wide range of oligosaccharide sequences within several categories of glycoprotein glycans. here were marked differences in staining reactions in the various microanatomical structures of the mucosa, particularly between pits and glands with the former more closely resembling the surface epithelium. A notable feature was the degree of difference in the staining between a substantial sub-population of cells within the neck region and the epithelium of both the pits and glands. These neck cells resembled the pit cells with some lectins, glandular cells with some others and neither with some other lectins. Overall, the differences between the pit, gland and neck epithelia were diverse and numerous, and could not be explained by altered activity of a small set of glycosyltransferases. Widespread alterations of glycans must have occurred (affecting terminal and internal parts of their structures) and the very different glycotypes of the pit, neck and gland epithelia are, therefore, suggestive of the existence of three cell lineages within normal gastric epithelium.     

Electron microscopic demonstration of lectin binding sites in the taste buds of the European catfish Silurus glanis (Teleostei)

Taste buds in the European catfish Silurus glanis were examined with electron microscopic lectin histochemistry. For detection of carbohydrate residues in sensory cells and adjacent epithelial cells, gold-, ferritin- and biotin-labeled lectins were used. A post-embedding procedure carried out on tissue sections embedded in LR-White was applied to differentiate between the sensory cells: The lectins from Helix pomatia (HPA) and Triticum vulgare (WGA) bound to N-acetyl-galactosamine and to N-acetylglucosamine residues occurring especially in vesicles of dark sensory cells. This indicates a secretory function of these cells. Most light sensory cells--with some exceptions, probably immature cells--, are HPA-negative. The mucus of the receptor field and at the top of the adjacent epithelial cells was strongly HPA-positive. Pre-embedding studies were performed in order to obtain information about the reaction of the mucus with lectins under supravital conditions. The mucus of the taste bud receptor field exhibited intensive binding to WGA, but not to the other lectins tested. Most lectins bound predominantly to the surface mucus of the nonsensory epithelium and to the marginal cells close to the receptor field. The strong lectin binding to mucins and the relatively weak lectin binding to cell surface membranes in pre-embedding studies suggest that the mucus possibly serves as a barrier which is passed selectively only by a small amount of lectins or lectin-carbohydrate complexes. Lectin-carbohydrate interactions may play a role in recognition phenomena on the plasmalemmata of the taste bud sensory cells. Recognition processes directed to bacteria or viruses should be considered as well.     

Postnatal development of lectin binding sites in the rat ventral prostate

Summary Five Fluorescein-isothiocyanate (FITC)-labelled lectins were used to study the postnatal development of carbohydrate constituents in the rat ventral prostate: Concanavalin A (Con A), wheat germ agglutinin (WGA), peanut agglutinin (PNA),Dolichos biflorus agglutinin (DBA) andRicinus communis agglutinin I (RCA-I) With all the lectins, tested, except RCA-I, specific binding sites could be shown for every stage of differentiation in the glandular epithelium. Binding sites for Con A, WGA, PNA and DBA were found from day 10 to 13 post partum onwards. Each lectin showed a characteristic localization. Binding sites for the lectins used changed to different extents during the following two weeks. After the 24th day post partum no further changes in the lectin binding pattern could be found. The development of the lectin binding properties showed that the changes in carbohydrate-containing constituents of the prostate correlate with the beginning of prostatic secretion and to prostatic epithelial differentiation. In the periacinar stroma the development of the lectin binding pattern was similar to that in the glandular epithelium. The changes of stromal binding sites for Con A and WGA during epithelial differentiation may reflect the changes of epithelial-stromal interactions in the prostate.     

Gold-conjugated arabinogalactan-protein and other lectins as ultrastructural probes for the wheat/stem rust complex

Arabinogalactan-protein (AGP, "beta-lectin") was isolated from leek seeds, tested for specificity, conjugated with gold colloids, and used as a cytochemical probe to detect beta-linked bound sugars in ultrathin sections of wheat leaves infected with a compatible race of stem rust fungus. Similar sections were probed with other gold-labeled lectins to detect specific sugars. AGP-gold detected beta-glycosyl in all fungal walls and in the extrahaustorial matrix. Other lectin gold conjugates localized galactose in all fungal walls except in walls of the haustorial body. Limulus polyphemus lectin bound only to the outermost layer of intercellular hyphal walls of the fungus. Binding of these lectins was inhibited by their appropriate haptens and was diminished or abolished in specimens pretreated with protease, indicating that the target substances in the tissue were proteinaceous or that polysaccharides possessing affinity to the lectin probes had been removed by the enzyme from a proteinaceous matrix by passive escape. Binding of Lotus tetragonolobus lectin was limited to the two outermost fungal wall layers but was not hapten-inhibitable. Limax flavus lectin, specific for sialic acids, had no affinity to any structure in the sections. In the fungus, the most complex structure was the outermost wall layer of intercellular hyphal cells; it had affinity to all lectins tried so far, except to Limax flavus lectin and to wheat germ lectin included in an earlier study. In the host, AGP and the galactose-specific lectins bound to the inner domain of the wall in areas not in contact with the fungus. At host cell penetration sites, affinity to these lectins often extended throughout the host wall, confirming that it is modified at these sites. Pre-treatment with protease had no effect on lectin binding to the host wall. After protease treatment, host starch granules retained affinity to galactose-specific lectins, but lost affinity for AGP.     

Changes in lectin-binding pattern in the digestive tract of Xenopus laevis during metamorphosis. II. Small intestine.

The binding of seven lectins (concanavalin A, Con A; Dolichos biflorus agglutinin, DBA; peanut agglutinin, PNA; Ricinus communis agglutinin I, RCA-I; soybean agglutinin, SBA; Ulex europeus agglutinin, UEA-I; and wheat germ agglutinin, WGA) to the small intestine in metamorphosing Xenopus laevis was studied by the avidin-biotin-peroxidase (ABC) method. The staining pattern of the epithelium with all lectins except for UEA-I and Con A changed gradually during metamorphic climax; the main component of the epithelium, absorptive cells, gradually became positive for DBA, PNA, and SBA and the scattered goblet cells for RCA-I and WGA. On the other hand, the change of the staining pattern in the connective tissue occurred only for Con A, RCA-I, and WGA, and this change took place rapidly at the beginning of climax (stage 60). Increased staining for Con A and WGA at stage 60 was observed only in a group of connective tissue cells close to the epithelium and in the basement membrane. As metamorphosis progressed, this localization of the staining intensity became less clear. At the completion of metamorphosis (stage 66), the absorptive cells were stained with all lectins except for UEA-I, whereas the goblet cells stained only with RCA-I and WGA. These results indicate that lectin histochemistry can distinguish between larval and adult cells of both two epithelial types (absorptive and goblet cells). The technique may also identify a group of connective tissue cells, close to the epithelium, that possibly induce the metamorphic epithelial changes.     

Characterization of glycoconjugates in the bovine endometrium and chorion by lectin histochemistry

Lectin binding patterns were examined on normal bovine endometrium and bovine placentomes during four stages of pregnancy using 13 biotinylated lectins. Lectin binding intensity increased in early pregnancy for many lectins, whereas binding to fucosyl residues decreased. Persistence of strong lectin binding later in pregnancy usually was limited to the arcade and intercotyledonary trophoblastic cells. Binding of some lectins to cell surfaces was prominent, particularly in early pregnancy. A few lectins were excellent markers for binucleate trophoblastic cells. These distinctive surface and binucleate cell binding patterns on placentomes and endometrial epithelium are useful markers of trophoblastic cell-endometrial epithelial cell surface interactions and of binucleate cell differentiation.     

Glycosylation profiles of airway epithelium after repair of mechanical injury in guinea pigs

Glycosylated structures on the cell surface have a role in cell adhesion, migration, and proliferation. Repair of the airway epithelium after injury requires each of these processes, but the expression of cell surface glycosylation of airway epithelial cells after injury is not known. We examined cell surface glycosylation using lectin-binding profiles of normal and repairing epithelia in Hartley guinea pigs from 0 to 14 days after mechanical injury. The epithelium regenerated completely over 7 days. In normal trachea, galactose- or galactosamine-specific lectins (14 of 20 tested) labelled epithelial cells, but fucose, mannose, and other sugar-specific lectins (15 tested) did not. GSA-2, a glucosamine-specific lectin, labelled epithelial cells weakly in uninjured tracheas, but intense labelling was noted in basal and non-ciliated columnar cells adjacent to the injury site over 3h to 14 days after injury. Labelling of these cells peaked at 12h and 5 days after injury respectively. Similar patterns were seen with lectins AlloA and HAA but not with CPA during repair. The binding of the lectin DSA to proteins collected from primary cultures of airway epithelial cells decreased substantially after treatment for 24h with either transforming growth factor- or interleukin-1, but that of the CPA lectin did not. We demonstrate changes in glycosylation profiles of airway epithelial cells coordinate with repair after mechanical injury. These changes may be useful to study mechanisms by which repair is regulated.     

Lectin histochemistry of normal human gastric mucosa

Information about the saccharides expressed in gastric mucosa is mostly limited to the glycan content of gastric mucins and there are only a few studies of the glycoprofiling of the constituent cells and their components. Knowledge of the glycan expression of normal gastric mucosa is necessary for the interpretation of the significance of changes of expression in disease. A lectin histochemical study of normal human gastric (body) mucosa was performed using 27 lectins chosen to probe for a wide range of oligosaccharide sequences within several categories of glycoprotein glycans. There were marked differences in staining reactions in the various microanatomical structures of the mucosa, particularly between pits and glands with the former more closely resembling the surface epithelium. A notable feature was the degree of difference in the staining between a substantial sub-population of cells within the neck region and the epithelium of both the pits and glands. These neck cells resembled the pit cells with some lectins, glandular cells with some others and neither with some other lectins. Overall, the differences between the pit, gland and neck epithelia were diverse and numerous, and could not be explained by altered activity of a small set of glycosyltransferases. Widespread alterations of glycans must have occurred (affecting terminal and internal parts of their structures) and the very different glycotypes of the pit, neck and gland epithelia are, therefore, suggestive of the existence of three cell lineages within normal gastric epithelium. Published in 2004. This revised version was published online in July 2006 with corrections to the Cover Date.