Lectin binding in skeletal muscle. Evaluation of alkaline phosphatase conjugated avidin staining procedures

Zonal variation in the distribution of an alpha 1-acid glycoprotein glycoform receptor in human adrenal cortex

Using a histochemical technique with three different alpha 1-acid glycoprotein glycoform one glycoform specific receptor has been identified in human adrenal cortex. The receptor is associated to alpha 1-acid glycoprotein glycoform B and alpha 1-acid glycoprotein glycoform C. The glycoform specific receptor was located in the cytoplasm of glomerulosa and outer fasciculata cells. The intensity of the reaction product decreased in the fasciculata, and no staining was seen in inner fasciculata and reticularis. Inhibition with the simple sugars, mannose and GlcNAc confirmed a lectin-like reaction. The binding activity was dependent on the presence of calcium ions and not on thiol reagents. Thus the lectin-like receptor may belong to the C-type lectin family. Using an antibody to alpha 1-acid glycoprotein the presence of alpha 1-acid glycoprotein was observed in the same location as the glycoform specific receptor. The binding of alpha 1-acid glycoprotein glycoform B and alpha 1-acid glycoprotein glycoform C to the glycoform specific receptor is inhibited by the steroid hormones cortisone, aldosterone, estradiol and progesterone but not by testosterone. The pronounced changes in the distribution of AGP and its glycoform receptors during cell differentiation in the adrenal cortex suggest that AGP and its complementary lectins belong to the group of lectins which control differentiation and spatial position.

Lectin-like receptor for alpha 1-acid glycoprotein in the epithelium of the rat prostate gland and seminal vesicles

BACKGROUND

A receptor for alpha 1-acid glycoprotein glycoforms AGP-B and AGP-C in the epithelium of the rat prostate gland and seminal vesicles is described.

METHODS

The interaction between AGP-glycoforms and their receptor is a lectin-like interaction confirmed by inhibition of the binding by mannose and N-Acetyl-D-glucosamine.

RESULTS

In vitro the receptor was also inhibited by the steroid hormones cortisone, aldosterone, progesterone, and estradiol, but not by testosterone. A significant regional variation in the expression of AGP-lectin receptor and in the localization of AGP was seen in rat prostate and seminal vesicles. The localization of the AGP lectin receptor is compared to the localization of glycoprotein AGP, and small differences are found.

CONCLUSIONS

It is proposed the AGP receptors in the prostate and seminal vesicles belong to a group of lectins in the control of differentiation and organ formation.

Two lectin-like receptors for alpha 1-acid glycoprotein in mouse testis

Three glycoforms of alpha 1-acid glycoprotein (AGP) were biotinylated to examine their binding in mouse testis by light microscopy. The transition from one stage to another in the spermatogenic cycle is marked with an appearance of a receptor for the Concanavalin A (Con A) non-reactive glycoform AGP-A in the cytoplasm of spermatocytes, young spermatids and Sertoli cells. This receptor disappears in the late stages of the spermatids. The Con-A intermediately reactive and the Con-A reactive glycoforms, AGP-B and AGP-C, showed weak reaction in the cytoplasm of spermatocytes, spermatids and Sertoli cells and, at the last stages in the spermatogenic cycle, a very strong reaction in the late elongated spermatids and the apical extensions of Sertoli cells. The interactions are lectin-like as confirmed by inhibition with simple sugars. In addition, the bindings were inhibited by steroid hormones. AGP-A was inhibited by testosterone, oestradiol and progesterone, while AGP-B and AGP-C were inhibited by mannose, GlcNAc, cortisone, aldosterone, oestradiol and progesterone. The receptors and the corresponding AGP glycoforms may be adhesion molecules between Sertoli cells and the spermatogenic cells and may have a function as a regulatory factor for spermatozoa development.

Glycosylation pattern and enzyme activities in atrophic, angulated skeletal muscle fibres from ageing rats

In this study enzyme activities and lectin binding patterns in skeletal muscle from very old rats were investigated in order to evaluate changes in enzyme activity or carbohydrate expression in senile muscle. Activities for adenosine triphosphatase (ATPase), succinic dehydrogenase, non-specific esterase and the binding pattern for 31 lectins were investigated in the soleus muscles from very old (36 months) and young (3 months) rats. In ageing muscles atrophic, angulated muscle fibres are frequent. In cryostat sections these fibres were mostly but not always type II defined by the myosin ATPase reaction; few showed a strong esterase activity. Some showed strong activity for succinic dehydrogenase while others were weakly reacting. A number of lectins strongly bound to the sarcoplasm in angulated fibres while the binding to normal fibres in both old and young rat muscle was much weaker or even absent. Preferential binding to the ageing, angulated fibres was seen with Aleuria aurentia, Galantus nivalis, Caragana abborecens, Triticum vulgaris, Maackia amurensis, Sambucus nigra, Phaseolus vulgaris erythroagglutinin, and Phaseolus coccineus. Samples of homogenized and centrifuged muscles were run by electrophoresis and the gels blotted to nitrocellulose paper. Subsequent lectin staining of the blots detected that two glycoproteins with molecular weights around 25,000 and 21,000 daltons were present in old muscle, but not in young. Aberrant or elevated expression of sarcoplasmic glycoconjugates is involved in ageing muscle atrophy.

Fucose expression in skeletal muscle: a lectin histochemical study

Binding sites for three fucose specific lectins, Aleuria aurantia agglutinin (AAA), Lotus tetragonolobus agglutinin (LTA) and Ulex europeus I agglutinin (UEA I), were investigated in sections from normal human and rat muscles, in muscle from patients with Duchenne muscular dystrophy (DMD) and in denervated and devascularized rat muscle. In normal human and rat muscle AAA detected fucosylated glycocompounds in the sarcoplasm, sarcolemma, interfibre connective tissue and vascular structures. In normal human muscle addition of fucose to the AAA incubation medium or treatment of the sections with formaldehyde followed by periodic oxidation before lectin incubation strongly inhibited the staining at all sites other than endothelial cells. In normal rat muscle the same staining procedures strongly inhibited the AAA binding at all sites other than the sarcolemma. Incubation with LTA resulted in a diffuse reaction around the vascular structures in rat muscle, while in human muscle a moderate, homogeneous staining was present in all muscle fibres. Treatment of the sections with formaldehyde and periodic acid before incubation with LTA resulted in strongly labelled muscle capillaries in both human and rat muscle. The only elements in the muscle tissues that were stained with UEA I were human endothelial cells. In denervated and devascularized rat muscle incubation with AAA revealed a novel fucose expression that appeared intracellularly in some necrotic fibres. The AAA-positive fucose residues in the sarcolemma of normal muscle fibres that were resistant to periodic acid oxidation could not be shown by AAA in denervated muscle. In DMD muscle a cryptic sarcolemmal fucose expression could be shown with AAA.(ABSTRACT TRUNCATED AT 250 WORDS)

Chicken adenovirus (CELO virus) particles augment receptor-mediated DNA delivery to mammalian cells and yield exceptional levels of stable transformants

Delivery of genes via receptor-mediated endocytosis is severely limited by the poor exit of endocytosed DNA from the endosome. A large enhancement in delivery efficiency has been obtained by including human adenovirus particles in the delivery system. This enhancement is probably a function of the natural adenovirus entry mechanism, which must include passage through or disruption of the endosomal membrane. In an effort to identify safer virus particles useful in this application, we have tested the chicken adenovirus CELO virus for its ability to augment receptor-mediated gene delivery. We report here that CELO virus possesses pH-dependent, liposome disruption activity similar to that of human adenovirus type 5. Furthermore, the chicken adenovirus can be used to augment receptor-mediated gene delivery to levels comparable to those found for the human adenovirus when it is physically linked to polylysine ligand-condensed DNA particles. The chicken adenovirus has the advantage of being produced inexpensively in embryonated eggs, and the virus is naturally replication defective in mammalian cells, even in the presence of wild-type human adenovirus.

Identification of capillaries in sections from skeletal muscle by use of lectins and monoclonal antibodies reacting with histo-blood group ABH antigens

This study was performed to evaluate the application of different lectins and monoclonal antibodies against ABH antigens to detect and characterize carbohydrate structures in capillaries of skeletal muscle from humans and laboratory animals. Blood group specific lectins (Griffonia simplicifolia, Griffonia simplicifolia isolectin B4, Lotus tetragonolobus, Ulex europaeus, and Dolichos biflorus) and monoclonal antibodies reacting with histo-blood group carbohydrate antigens belonging to type 1 (Le(a)) and type 2 (H, A and Le(y)) chains were used as histological markers for capillaries in sections from skeletal muscle. The material consisted of 20 human masseter muscle biopsies from individuals with known blood types: (eight blood group O, nine blood group A, two blood group B, and one blood group AB) and masseter muscles specimens from different laboratory animals (mouse, rat, rabbit, cat, dog, pig, cow, and macaca monkey). Unfixed sections and an avidin alkaline phosphatase method were used to visualize the specific reaction. Ulex lectin stained capillaries in all human biopsies either strongly or moderately. Strong muscle capillary reaction was observed in biopsies from O, B and AB individuals while capillaries from A individuals were only moderately stained. Griffonia simplicifolia marked capillaries in A, B, and AB individuals and Griffonia simplicifolia isolectin B4 stained capillaries in muscle biopsies from B and AB donors. Dolichos biflorus was a weak marker of muscle capillaries from A individuals. Only capillaries from O individuals were stained with the antibody against H type 2. Capillary reaction was not observed with the other antibodies used. Girffonia simplicifolia was an excellent marker for capillaries in mouse muscle while Griffonia simplicifolia isolectin B4 is recommended for rat muscles.(ABSTRACT TRUNCATED AT 250 WORDS)