Griffonia simplicifolia-I Research Articles

Hypoxic Ventilatory Reactivity in Experimental Diabetes.

Diabetes, apart from generalized neuropathy and microangiopathy, involves tissue hypoxia, which may drive chronic proinflammatory state. However, studies on the ventilatory control in diabetes are sparse and conflicting. In this study we examined the function and morphology of diabetic carotid bodies (CBs). Diabetes was evoked in Wistar rats with streptozotocin (70 mg/kg, i.p.). The acute hypoxic ventilatory responses (HVR) to 12 and 8 % O(2) were investigated in conscious untreated rats after 2 and 4 weeks in a plethysmographic chamber. CBs were dissected and subjected to morphologic investigations: (1) electron transmission microscopy for ultrastructure and (2) laser scanning confocal microscopy to visualize the microvascular bed in sections labeled with the lectin Griffonia simplicifolia-I (GSI), an endothelial cell marker, and fluorescein isothiocyanate (FITC). All findings were referenced to the normal healthy rats. We found that diabetes distinctly dampened the HVR. At the ultrastructural level, the diabetic CB displayed proliferation of connective tissue and neovascularization deranging the interglomal structure, and lengthening the O(2) diffusion path from capillaries to chemoreceptor cells. The chemoreceptor cells remained largely unchanged. The endothelial cell labeling confirmed the intensive angiopathy and the induction of microvessel growth. We conclude that diabetes hampers the chemical regulation of ventilation due to remodeling of CB parenchyma, which may facilitate chronic hypoxia and inflammation in the organ.

Use of fluorescent lectin binding to distinguish Teladorsagia circumcincta and Haemonchus contortus eggs, third-stage larvae and adult worms

Lectin binding to carbohydrates on parasite surfaces has been investigated as a method of distinguishing adult worms, eggs and sheathed and exsheathed L3 of Teladorsagia circumcincta and Haemonchus contortus, economically important abomasal parasites in temperate climates. Both species were maintained as pure laboratory cultures of field isolates from New Zealand. Each of the four life cycle stages could be distinguished by the binding of at least one lectin: adult worms by Sambucus nigra agglutinin (SNA); eggs by peanut agglutinin (PNA), ConcavalinA and Lens culinaris agglutinin (LCA); exsheathed L3 by Griffonia simplicifolia-I lectin (GSL-I) and Lotus tetragonolobus lectin (LTL) and sheathed L3 by Aleuria aurantia lectin (AAL). The whole surface of both adult T. circumcincta and H. contortus strongly bound lectins specific for N-acetylglucosamine (GlcNAc), N-acetylgalactosamine (GalNAc), mannose and fucose, but the two species could be distinguished by SNA binding only to T. circumcincta. Eggs could be distinguished by the binding of mannose-specific PNA to H. contortus and GalNAc-specific LCA and PSA to T. circumcincta eggs. GalNAc, GlcNAc and mannose lectins bound to the cuticle and over the excretory pores of a large proportion of sheathed L3 of both species, but only the H. contortus surface had exposed fucose or sialic acid complexes. The distinguishing lectin for sheathed L3 was AAL, which did not bind to T. circumcincta, but bound weakly to the head region of all fresh H. contortus and to 50-90% after 3months storage. The cuticle of exsheathed L3 was unresponsive to all 19 lectins, and any binding was restricted to the head and tail regions. L3 exsheathed after 2-4months storage could be distinguished by the binding of GSL-I and LTL to H. contortus but not to T. circumcincta. Lectin binding could be a useful adjunct in identifying L3, but lacked the consistency to be definitive, whereas it could be further developed as a practical method of distinguishing parasitic nematodes at other stages in the life cycle, particularly the eggs.

Identification of exopolysaccharide‐deficient mutants of Mycoplasma pulmonis

The presence of capsular exopolysaccharide (EPS) in Mollicutes has been inferred from electron micrographs for over 50 years without conclusive data to support the production of complex carbohydrates by the organism. Mycoplasma pulmonis binds the lectin Griffonia simplicifolia I (GS-I), which is specific for terminal beta-linked galactose residues. Mutants that failed to produce the EPS bound by GS-I were isolated from a transposon library. All of the mutants had the transposon located in open reading frame MYPU_7410 or MYPU_7420. These overlapping genes are predicted to code for a heterodimeric pair of ABC transporter permeases and may code for part of a new pathway for synthesis of EPS. Analysis by lectin-affinity chromatography in conjunction with gas chromatography demonstrated that the wild-type mycoplasma produced an EPS (EPS-I) composed of equimolar amounts of glucose and galactose that was lacking in the mutants. Phenotypic analysis revealed that the mutants had an increased propensity to form a biofilm on glass surfaces, colonized mouse lung and trachea efficiently, but had a decreased association with the A549 lung cell line. Confounding the interpretation of these results is the observation that the mutants missing EPS-I had an eightfold overproduction of an apparent second EPS (EPS-II) containing N-acetylglucosamine.

Lectins binding during alloxan-induced diabetes in rat soleus muscle

Membrane structural changes of soleus muscle of alloxan-diabetic rats were detected with a panel of six biotinylated lectins. Samples of muscles were obtained from normal and diabetic rats. The biotinylated lectins in staining were detected by avidin-peroxidase complex. Lectin stainning of soleus muscle cryostat sections from alloxan-diabetic rats were compared with similar cryostat sections from normal rats. All lectins were bounded to soleus muscle cell membranes of normal and diabetic rats except the Ulex europeus agglutinin I (UEA-I). UEA-I was not stained for cell membranes of soleus muscles of normal and diabetic rats. But intercellular areas of normal and diabetic soleus muscle were stained for UEA-I. Griffonia simplicifolia I (GS-I) lectin was bounded more strongly to cell membrane of diabetic rats than other lectins. Not only cell membranes but also cytoplasmic miyofibrills of diabetic muscle cells were stained by Griffonia simplicifolia (GS1) lectin. It was concluded that cell membranes of soleus muscle of diabetic rats were differently stained for lectins than those of normal rats. Our data can supplement on the use of lectins as probes for changes in carbohydrate-containing constituents of the alloxan-diabetic muscle cell membrane information obtained from normal and diabetic

Coronary artery embryogenesis in cardiac defects induced by retinoic acid in mice

Although normal coronary artery embryogenesis is well described in the literature, little is known about the development of coronary vessels in abnormal hearts. We used an animal model of retinoic acid (RA)-evoked outflow tract malformations (e.g., double outlet right ventricle [DORV], transposition of the great arteries [TGA], and common truncus arteriosus [CTA]) to study the embryogenesis of coronary arteries using endothelial cell markers (anti-PECAM-1 antibodies and Griffonia simplicifolia I (GSI) lectin). These markers were applied to serial sections of staged mouse hearts to demonstrate the location of coronary artery primordia. In malformations with a dextropositioned aorta, the shape of the peritruncal plexus, from which the coronary arteries develop, differed from that of control hearts. This difference in the shape of the early capillary plexus in the control and RA-treated hearts depends on the position of the aorta relative to the pulmonary trunk. In both normal and RA-treated hearts, there are several capillary penetrations to each aortic sinus facing the pulmonary trunk, but eventually only 1 coronary artery establishes patency with 1 aortic sinus. The abnormal location of the vessel primordia induces defective courses of coronary arteries; creates fistulas, a single coronary artery, and dilated vessel lumens; and leaves certain areas of the heart devoid of coronary artery branches. RA-evoked heart malformations may be a useful model for elucidating abnormal patterns of coronary artery development and may shed some light on the angiogenesis of coronary artery formation.

Leptomonas wallacei Shows Distinct Morphology and Surface Carbohydrates Composition Along the Intestinal Tract of Its Host Oncopeltus fasciatus (Hemiptera: Lygaeidae) and in Axenic Culture

Leptomonas wallacei is a monoxenic trypanosomatid that colonizes the digestive tract of the phytophagous hemipteran Oncopeltus fasciatus. This infection was specific and took place exclusively in midgut intestinal ventricles V3 and V4, and in the hindgut. Abundances of parasites in the hindgut were 54% less than those in the hindgut. Parasites in the hindgut were more slender and had a longer flagellum than those from the hindgut, which were rounded, with a shorter flagellum. Moreover, hindgut forms expressed sugar residues on the cell surface, recognized by the lectins from Griffonia simplicifolia-I (alpha-galactose, alpha-N-acetyl-galactosamine) and Helix pomatia (N-acetyl-galactosamine); those sugar residues were not present in protozoa from the midgut. In culture, parasites were morphologically similar to midgut forms, but differed from them because they did not express sugar residues that bind to lectin (beta-galactose(1-3) N-acetyl-galactosamine) from Arachis hypogaea.

N-Glycan Structures of Pigeon IgG: A MAJOR SERUM GLYCOPROTEIN CONTAINING Galα1–4Gal TERMINI

We had shown previously that all major glycoproteins of pigeon egg white contain Galalpha1-4Gal epitopes (Suzuki, N., Khoo, K. H., Chen, H. C., Johnson, J. R., and Lee, Y. C. (2001) J. Biol. Chem. 276, 23221-23229). We now report that Galalpha1-4Gal-bearing glycoproteins are also present in pigeon serum, lymphocytes, and liver, as probed by Western blot with Griffonia simplicifolia-I lectin (specific for terminal alpha-Gal) and anti-P1 (specific for Galalpha1-4Galbeta1-4GlcNAcbeta1-) monoclonal antibody. One of the major glycoproteins from pigeon plasma was identified as IgG (also known as IgY), which has Galalpha1-4Gal in its heavy chains. High pressure liquid chromatography, mass spectrometric (MS), and MS/MS analyses revealed that N-glycans of pigeon serum IgG included (i) high mannose-type (33.3%), (ii) disialylated biantennary complex-type (19.2%), and (iii) alpha-galactosylated complex-type N-glycans (47.5%). Bi- and tri-antennary oligosaccharides with bisecting GlcNAc and alpha1-6 Fuc on the Asn-linked GlcNAc were abundant among N-glycans possessing terminal Galalpha1-4Gal sequences. Moreover, MS/MS analysis identified Galalpha1-4Galbeta1-4Galbeta1-4GlcNAc branch terminals, which are not found in pigeon egg white glycoproteins. An additional interesting aspect is that about two-thirds of high mannose-type N-glycans from pigeon IgG were monoglucosylated. Comparison of the N-glycan structures with chicken and quail IgG indicated that the presence of high mannose-type oligosaccharides may be a characteristic of these avian IgG.

Renal Pathology in Fabry Disease

Fabry disease is an X-linked recessive lysosomal storage disease that is caused by deficient activity of the lysosomal enzyme α-galactosidase A (α-Gal A), an enzyme that cleaves terminal α-galactosyl residues. This deficiency results in progressive lysosomal accumulation of glycosphingolipid with

Lectin enhancement of the lipofection efficiency in human lung carcinoma cells

Poor transfection efficiency of human lung carcinoma cells by lipofection begs further development of more efficient gene delivery strategies. The purpose of this study was to determine whether lectins can improve the lipofection efficiency in lung carcinoma cells. A549, Calu3, and H292 cells grown to 90% confluence were transfected for 18 h with a plasmid DNA containing a β-galactosidase reporter gene (pCMVlacZ) using lipofectin plus a lectin as the vector. Ten different lectins, which exhibit a wide range of carbohydrate-binding specificities, were examined for their abilities to enhance the efficiency of lipofection. The transfected cells were assessed for transfection efficiency by β-galactosidase activity (units/μg protein) and % blue cells following X-Gal stain. Lipofectin supplemented with Griffonia simplicifolia-I (GS-I) yields largest enhancement of the lipofection efficiency in A549 and Calu3 cells (5.3- and 28-fold, respectively). Maackia amurensis gives the largest enhancement (6.5-fold) of lipofection efficiency in H292 cells. The transfection efficiency correlates with the amounts of DNA delivered to the nucleus. Binding of FITC-labeled GS-I and the enhancement of the lipofection efficiency by GS-I were inhibited by α-methyl- d-galactopyranoside, indicating an α-galactoside-mediated gene transfer to lung carcinoma cells. We conclude that lectin-facilitated lipofection is an efficient gene delivery strategy. Employment of cell type-specific lectins may allow for efficient cell type-specific gene targeting.

The role of valence on the high-affinity binding of Griffonia simplicifolia isolectins to type A human erythrocytes.

The Griffonia simplicifolia-I (GS-I) isolectins have been used to probe the effect of lectin valence on their high-affinity binding to human erythrocytes. These tetrameric lectins are composed of A and B subunits and constitute a series of five isolectins (A4, A3B, A2B2, AB3, B4). The A subunit is specific for alpha-D-GalNAc end groups and binds to the blood type A determinant GalNAcalpha1, as well as to terminal alpha-D-Gal groups found on type B cells. The B subunit is specific for alpha-D-Gal end groups, and binds very specifically to type B erythrocytes. This series of isolectins is tetravalent (A4), trivalent (A3B), divalent (A2B2), and monovalent (AB3) for type A erythrocytes; thus, this system provides the opportunity to examine the effect of lectin valency on the association constants of these GS-I isolectins binding to cells. Cell binding experiments carried out using 125I-labeled GS-I isolectins and type A human erythrocytes allowed us to demonstrate that (1) the association constant of the isolectin monovalent for alpha-D-GalNAc (AB3) is virtually identical to its association constant for the haptenic sugar methyl-N-acetyl-alpha-D-galactosaminide, reported previously, and (2) the association constant of the GS-I isolectins for human type A erythrocytes increases with increasing valency of the isolectin. These results indicate that the increased affinity displayed by the GS-I isolectins for human type A erythrocytes is dependent on their multivalency, and not on an extended binding site nor on nonspecific, or noncarbohydrate, interactions of the lectin with the cell surface. These findings should be of general relevance to understanding the high-affinity interactions observed between other multivalent proteins and multivalent ligands (e.g., cell surfaces).

Growth of Arterioles in Chronically Stimulated Adult Rat Skeletal Muscle

The purpose of this study was to test the hypothesis that capillary growth induced by chronic electrical stimulation of skeletal muscle is accompanied by the growth of small arterioles. Lower limb flexor muscles of Sprague-Dawley rats were stimulated by electrodes implanted in the vicinity of the peroneal nerve at 10 Hz for 8 h/d for 2 and 7 days. Cryostat sections from the proximal, middle, and distal regions of the extensor digitorum longus muscle (EDL) were fluorescently immunolabeled with alpha-smooth muscle actin (alpha SMA) and myosin heavy chain (MHC) to identify mature (alpha SMA and MHC-positive) and immature (alpha SMA-positive, MHC-negative) arterioles. The fluorescent derivative of the lectin Griffonia simplicifolia I (GSI) was used to identify all microvessels, including arterioles, capillaries, and venules. The number of vessels positive for GSI or alpha SMA surrounding muscle fibers was similar in all three muscle regions (proximal, middle, distal). The mean values +/- SEM for GSI-positive vessels from all regions were similar in control (4.3 +/- 0.07) and 2-day stimulated (4.7 +/- 0.08) but higher in 7-day stimulated muscles (6.7 +/- 0.1, p < 0.05), thus confirming the previous findings on capillary growth. A similar increase was found in the number of alpha SMA positive vessels < or = 10 microns outer diameter (1.3 +/- 0.09 versus 0.4 +/- 0.03 around muscle fibers in controls). The density of terminal arterioles (< or = 10 microns) was slightly but not significantly higher after 2 days of stimulation (19.5 +/- 4 versus 15.6 +/- 2 profiles/mm2 in control muscles) and significantly higher after 7 days (33 +/- 7). While a similar increase was observed in the density of preterminal arterioles > 10 microns (17 +/- 3 control, 22 +/- 3 at 2 days and 40 +/- 5 at 7 days), the density of MHC-positive vessels muscles stimulated for 7 days was unchanged. Seven-day stimulated muscle also had a fivefold higher density of microvessel profiles < or = 10 microns that were only partially surrounded by alpha SMA. This considerably exceeds the relative increase in the number of capillaries and thus supports the concept of arteriolar growth by transformation from capillaries. Chronic electrical stimulation results in an early increase in the number of immature (MHG-negative), but not mature (MHC-positive) arterioles, a process that accompanies the increase in capillarization. The great increase in the number of microvessels only partially covered by alpha SMA suggests arteriolization of capillaries as a contributing mechanism in this growth.

Basic fibroblast growth factor-induced angiogenic phenotype in mouse endothelium. A study of aortic and microvascular endothelial cell lines.

The mouse is the most commonly used species for in vivo studies on angiogenesis related to tumor development. Yet, to the best of our knowledge, very few reports on the in vitro interaction of the angiogenic basic fibroblast growth factor (bFGF) with mouse endothelial cells are available. Three mouse endothelial cell lines originated from aorta (MAECs), brain capillaries (MBECs), and heart capillaries (MHECs) were characterized for endothelial phenotypic markers, in vivo tumorigenic activity, and the capacity to respond in vitro to bFGF. These cells express angiotensin-converting enzyme, acetylated LDL receptor, constitutive endothelial nitric oxide synthase, and vascular cell adhesion molecule-1 and bind Griffonia simplicifolia-I lectin. When injected subcutaneously in nude mice, MAECs induced the appearance of slow-growing vascular lesions reminiscent of epithelioid hemangioendothelioma, whereas MBEC xenografts grew rapidly, showing Kaposi's sarcoma-like morphological features. No lesions were induced by injection of MHECs. MAECs, MBECs, and MHECs expressed both low-affinity heparan sulfate bFGF-binding sites and high-affinity tyrosine kinase receptors (FGFRs) on their surfaces. In particular, MAECs expressed FGFR-2/bek mRNA, whereas microvascular MBECs and MHECs expressed FGFR-1/flg mRNA. Accordingly, bFGF induced a mitogenic response and the phosphorylation of extracellular signal-regulated kinase-2 in all the cell lines. In contrast, upregulation of urokinase-type plasminogen activator expression was observed in bFGF-treated microvascular MBECs and MHECs but not in MAECs. Also, bFGF-treated MBECs and MHECs but not MAECs invaded a three-dimensional fibrin gel and formed hollow, capillary-like structures. The relevance of the modifications of the fibrinolytic balance of mouse microvascular endothelium in bFGF-induced angiogenesis was validated in vivo by a gelatin-sponge assay in which the plasmin inhibitors tranexamic acid and epsilon-aminocaproic acid given to mice in the drinking water inhibited neovascularization induced by the growth factor. In conclusion, differences in response to bFGF exist between large-vessel MAECs and microvascular MBECs and MHECs. Both in vitro and in vivo data point to a role of the profibrinolytic phenotype induced by bFGF in microvascular endothelial cells during mouse angiogenesis. Our observations make these endothelial cell lines suitable for further studies on mouse endothelium during angiogenesis and in angioproliferative diseases.

Cellular heterogeneity in the membrana granulosa of developing rat follicles: assessment by flow cytometry and lectin binding.

The hormone-mediated maturation of ovarian follicles is apparently accompanied by position-specific differentiation of cells of the membrana granulosa. We have assessed the extent of this cellular heterogeneity by flow cytometry using a variety of fluorescein isothiocyanate-labeled lectins as probes. Follicular development was stimulated in immature rats by treatment with either diethylstilbestrol (DES) or equine CG (eCG). Lectin binding to monodispersed rat granulosa cells was then analyzed by flow cytometry. Our results demonstrate that there are two distinct populations of small (4-7 microM) and large (9-12 microM) granulosa cells in follicles from DES- and eCG-treated animals. Both populations appear to be mitotically active and show specific lectin-binding characteristics. Six lectins (canavalia ensiforms, triticum vulgaris, maclura pomifera, erythrina cristagalli, jacalin, and vicia villosa) bind equally to both small and large granulosa cells from the DES- and eCG-treated rats. In contrast, no binding to either cell population was detected with six other lectins (dolichos biflorus, griffonia simplicifolia-II, lycopersicon esculentum, datura stramonium, solanum tuberosum, and ulex europaeus). Furthermore, four galactose-binding lectins (bauhinia purpurea, glysine maximus, griffonia simplicifolia-I, and arachis hypogaea) were found to identify specific subsets of granulosa cells. Three of these lectins (bauhinia purpurea, glysine maximus, and griffonia simplicifolia-I) bind to only small granulosa cells from either DES- or eCG- treated immature rats. The fourth lectin (arachis hypogaea) identifies subpopulations of both small and large granulosa cells. Application of the four galactose-specific lectins to fixed sections of frozen ovaries demonstrated binding to the perioocyte and cumulus granulosa cells. We conclude that cellular heterogeneity exists within the follicular epithelium at various stages-specific lectin-binding sites.

Glycoconjugates of the surface of the spermatozoa of Drosophila melanogaster: A qualitative and quantitative study

The important roles played by glycoconjugates in the recognition of gametes and in fertilization are well documented. In the present study, the nature and distribution of carbohydrate residues of the plasma membrane of spermatozoa of Drosophila melanogaster were characterized by use of FITC-conjugated lectins as probes. The plasma membrane bound agglutinins from Concanavalia ensiformis (Con A) and Pisum sativum (PSA), native and succinylated agglutinins from wheat germ (WGA and s-WGA), the A4 isoform of agglutinin-I from Griffonia simplicifolia (GSA-I A4), and, to a lesser extent, the lectins from Dolichus biflorus (DBA), lotus tetragonolobus (LTA), and Glycine maximus (SBA). Each lectin gave a specific pattern of binding. The extent of binding of Con A, WGA, s-WGA, and GSA-I A4 over the acrosomal region was greater than over nonacrosomal regions, indicating the concentration of alpha-mannose/alpha-glucose, beta-N-acetylglucosamine, and alpha-N-acetylgalactosamine residues in this area of the plasma membrane. The surface of the sperm failed to react with lectins from Ricinus communis (RCA-I), Limulus polyphemus (LPA), and Limax flavus (LFA) and with the B4 isoform of agglutinin-I from Griffonia simplicifolia-I (GSA-I B4). The plasma membrane over the nucleus did not react with any of the lectins tested. Quantitative analysis of binding of Con A, s-WGA, and GSA-I A4 to spermatozoa showed that only Con A bound consistently to the sperm surface, showing high affinity for the acrosomal area of the plasma membrane. The other lectins tested bound only to limited and variably sized fractions of the total population of sperm.(ABSTRACT TRUNCATED AT 250 WORDS)

Lectin Histochemistry of Normal and Herpesvirus-infected Bovine Nasal Mucosa

Proliferation of Pasteurella haemolytica serotype 1 in the nasal cavity following stress or viral infection is an important event in the pathogenesis of bovine pneumonic pasteurellosis. Enhanced adhesion of P. haemolytica to nasal mucosa could be one factor that predisposes animals to this proliferation. Nasal mucosa from normal and bovine herpesvirus-1 (BHV1)-infected cattle were examined histochemically for their glycoconjugate composition. Twenty lectins were screened, six of which were chosen for subsequent study. Three of these were specific for N-acetylgalactosamine (NAGal) (Dolichos biflorus, Glycine max, and Vicia villosa), and one each was specific for N-acetylgalactosamine/galactose (Griffonia simplicifolia-I), mannose/glucose (Canavalia ensiformis), and N-acetylglucosamine (Triticum vulgaris). For the surface mucosa and submucosal glands, there was greater reactivity in samples from BHV1-infected than from normal cattle for all six lectins. Reactivity was most prominent for the NAGal-specific lectins. Neuraminidase treatment of samples from normal and BHV1-infected cattle tended to result in greater lectin reactivity. Lectin reactivity was generally more intense in focally inflamed areas, but diffuse reactivity was not substantially affected by inflammation. BHV1-induced alteration of nasal mucosal glycoconjugates could enhance adhesion and colonization of P. haemolytica to nasal surfaces and may be one factor responsible for the increased number of P. haemolytica serotype 1 in the nasal cavity following viral infection.

Regional Differences In Spontaneously Occurring Angiogenesis In the Adult Rat Mesentery

Despite intensive study in the area of angiogenesis, relatively little is known about normal angiogenesis in adult animals. Preliminary studies using the Griffonia simplicifolia I (GSI) lectin as a microvascular marker indicated that capillary sprouting occurs in the clear "windows" of normal intact adult rat mesentery. The purpose of this study was to determine whether angiogenesis occurs uniformly within the mesenteric windows and whether maturational age affects the extent of angiogenesis in the absence of any experimental or pathological perturbation. Four groups of female Sprague-Dawley rats were used, "weanling" (4-5 weeks), "juvenile" (6-8 weeks), "young adult" (10-13 weeks), and "adult" (16-20 weeks). Microvessels sprouting into proximal and distal windows were delineated in whole mounts by use of fluorescent derivative of the GSI lectin. Microvascular sprouting, indicating angiogenesis, was found in all age groups, but was most frequent in the windows sampled from the distal region of the small intestine when compared with those from the proximal region. The mean number of microvessels per sample site was significantly higher in the distal windows of adults than in the weanling or juvenile rats. Angiogenesis was found to occur asymmetrically within the individual windows in the two adult groups, with significantly more angiogenesis on the intestinal side compared to that along the portal vessels. We conclude that there is an age-related increase in angiogenesis into the mesenteric windows, and that the intestinal side is more prone to spontaneous angiogenesis than is the portal side. These results have important applications to the use of mesentery as an assay system for intact vessels in adults and to the use of mesentery as an in vivo model system to bridge the gap between our understanding of angiogenesis in vivo and intact vascular systems.

Growth and differentiation of tracheal epithelial progenitor cells.

The purpose of these studies was to determine whether both basal and secretory rat tracheal epithelial (RTE) cells served as multipotent epithelial progenitors and whether both cell types gave rise to a similar "poorly differentiated" cell during the early phase of epithelial regeneration in denuded tracheal grafts. Griffonia simplicifolia I (GSI) lectin and flow cytometry were used for cell sorting. More than 98% of GSI-positive cells expressed plasma membrane alpha 1-3 terminal galactose (Gal), and 95% contained keratin 14 (K14), phenotypic markers for basal cells; < 1% were secretory or ciliated cells. Less than 2% of the GSI-negative cells expressed Gal or K14, but this fraction contained 16% ciliated cells and 54-79% secretory cells, dependent on whether periodic acid-Schiff staining or binding of an anti-secretory cell monoclonal antibody (RTE 12) was used as the criterion. Equal numbers of viable cells from either fraction were inoculated into denuded tracheal grafts, which were studied on days 1-14. At 24 h, greater numbers of GSI-negative than -positive cells were found attached to the graft wall; the keratin staining pattern of the attached cells was similar to that of the parent cell populations, but monoclonal antibody-detectable secretory and ciliated cell epitopes, originally present in the GSI-negative fraction, were lost. 5-Bromo-2'-deoxyuridine uptake was not seen at 24 h, but by 48 h all epithelial cells from both fractions entered the cell cycle. From 48 to 96 h, cells derived from either fraction were ultrastructurally indistinguishable; they were poorly differentiated and highly proliferative, and all expressed Gal and K14. A mature epithelium evolved from the poorly differentiated cells in both sets of grafts, but secretory and ciliated cells appeared earlier in grafts inoculated with GSI-negative cells. The results strongly suggest that in this model of tracheal epithelial regeneration both basal and secretory cells "dedifferentiated" into a similar highly proliferative phenotype from which a mucociliary epithelium "redifferentiated."

Lectin histochemistry on the skin of hairless descendants of mexican hairless dogs

The skin of hairless descendants of Mexican hairless dogs was investigated lectin-histochemically. Haired dogs were also used for comparative study. In the epidermis of infant pups, lectin staining revealed marked differences between hairless and haired dogs. Griffonia simplicifolia-I (GS-I) bound moderately to the cytoplasm of the stratum basale of hairless dogs, while no binding to that of haired dogs was observed. Bauhinia purpurea (BPA) showed positive staining for the stratum spinosum and basale of hairless dogs, while it was negative or weakly positive for the cytoplasm of both epidermal layers of haired dogs. Maclura pomifera (MPA) showed moderate to intense staining for the intercellular area of the stratum basale of hairless dogs, while no or weak staining was detected in that of haired dogs. Urex europeus-I (UEA-I) bound weakly to moderately to the cytoplasm and the intercellular area of the stratum spinosum of hairless dogs, whereas no or very weak staining was observed in those of haired dogs. Most of the lectins exhibited significant alterations in the epidermal staining pattern between infants and adults. Significant differences were not observed in adult canine epidermis between hairless and haired dogs. In conclusion, lectin histochemistry in hairless dogs revealed that there were different development steps in the epidermal cells between infants and adults.

Changes of lectin staining pattern of the Golgi stack during differentiation of the ameloblast in developing rat molar tooth germs

Changes of lectin staining patterns in the Golgi stack during cell differentiation were examined in the ameloblasts of developing rat molar tooth germs, using HRP-labeled lectins: Canavalia ensiformis (Con A), Griffonia simplicifolia I (GS-I), Glycine max (SBA), Ulex europeus I (UEA-I), Triticum vulgaris (WGA), and Arachis hypogaea (PNA). The Golgi stacks of the inner enamel epithelial cells and the presecretory ameloblasts were stained with the lectins, although the staining strength and pattern varied among the stacks with each lectin. In some cases, the reaction products for the lectins were observed in most or all saccules of the Golgi stack. In the secretory ameloblasts, however, discrete staining patterns of the Golgi stack were found for each lectin. The reaction products deposited in definite saccules of the Golgi stack of the secretory ameloblast, especially for UEA-I and PNA which stained only the trans Golgi saccules of the stack. The reaction-positive saccules distributed more extensively in the Golgi stack of the inner enamel epithelial cell and the presecretory ameloblast than in the secretory ameloblast. These findings suggest that the Golgi stack is not fully compartmentalized in the inner enamel epithelial cell and the presecretory ameloblast. It is proposed that, in the differentiating ameloblast, various glycosyltransferases may coexist in most saccules of the Golgi stack.

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.