Synthesis and antitumor activity evaluation of glycoconjugates derived from natural product harmine / 中国药科大学学报

@#Based on our previous work, the study herein designed and synthesized eight glycoconjugates of natural product harmine (14a-14h)by introducing a cyclohexylmethyloxyl group at its C7 position and coupling a methyl-2-amino-β-D-glucopyranoside to the N9 position through different lengths of alkyl chains.In vitro anti-tumor activity screening and structure-activity relationship studies showed that the antitumor activity of the conjugates increased with the lengthening of the alkyl chain in the linker.Compound 14h exhibited significantly better proliferative inhibitory activity against MDA-MB-231 breast cancer cells than harmine.As compared to harmine, the introduction of the carbohydrate moiety improved the water solubility of compound 14h and enhanced its tumor cell selectivity through the Warburg effect.Mechanism of action studies revealed that compound 14h induced apoptosis and G0/G1 cell cycle arrest in MDA-MB-231 cells, and inhibited tumor cell migration by interfering with epithelial-mesenchymal transition process.This study provides a new approach for the development of antitumor drugs based on harmine.

á-N-acetylglucosamine-linked O-glycans of sialoglycoproteins (Tc-mucins) from Trypanosoma cruzi Colombiana strain

Trypanosoma cruzi sialoglycoproteins (Tc-mucins) are mucin-like molecules linked to a parasite membrane via a glycosylphosphatidylinositol anchor. We previously determined the structures of Tc-mucin O-glycan domains from several T. cruzi strains and observed significant differences among them. We now report the amino acid content and structure of Tc-mucin O-glycan chains from T. cruzi Colombiana, a strain resistant to common trypanocidal drugs. Amino acid analysis demonstrated the predominance of threonine residues (42%) and helped to identify the O-glycans as belonging to a Tc-mucin family that contain a ²-galactofuranose (²-Galf) residue attached to an á-N-acetylglucosamine (á-GlcNAc) O-4, with the most complex glycan, a pentasaccharide-GlcNAc-ol with a branched trigalactopyranose chain, on the GlcNAc O-6. The presence of ²-Galf on O-glycans from T. cruzi Colombiana mucins supports the use of glycosylation as a phylogenetic marker for the classification of Colombiana in the T. cruzi I group.

Study on the immunogenicity of group A plus group C meningococcal glycoconjugate vaccine / 中华微生物学和免疫学杂志

Objective To investigate the immunogenicity of group A plus group C meningococeal glycoconjugate vaccine,namely dosage,immune memory and compatibility. Methods The mice were injected with group A plus group C meningococcal glycoconjugate vaccine with different dosages. Blood samples were taken on the 14th day after the last injection for testing the antibodies against polysaccharide A and C. After the optimal immunization dosage had been decided,the mice were inoculated separately with the monovalent group A and the monovalent group C and the bivalent group A plus group C glycoconjugate vaccine with one,two or three injections for observation of the effectiveness of different injections and the compatibilities. Results The dosage of 1.25 μg of each polysaccharide of group A and group C in bivalent glycoconjugate vaccine appears to be immunologically optimal to vaccinate the mice. Immunological memory could be induced in mice inoculated with the glycoconjugate vaccine,and the antigenic immunogenicity of the group A component and group C component in the formulation of group A plus group C meningococcal glycoconjugate vaccine was not affected. Conclusion Group A plus group C meningococcal glycoconjugate vaccine have good immunogenicity,immune memory and compatibility.

Glycoconjugates of the Duodenal Mucosa in Cold-treated Chipmunks / 체질인류학회지

To investigate changes of glycoconjugates (GC) on the duodenal mucosa of Korean chipmunks (Tamias sibiricus) after cold-treatment, chipmunks were maintained in cold conditions (6 C) for 3, 5 or 9 months in an attempt to mimic conditions occurring during seasonal hibernation. Most chipmunks were active as before until 3 months in the cold room and since then were hibernated. Although there was significant decrease in neutral GC in cold-treated chipmunks compared with warm chipmunks, acid GC changed little. As for histochemical properties of acid GC in the duodenum, the cold-treated chipmunk showed some differences, such as appearance of villus goblet cells which contained the mixture of sulfated and nonsulfated GC. The affinities for all lectins used in this study were shown in the columnar cells of the duodenal villus and crypt, more intensive DBA, SBA, PNA, BSL-1, RCA-1 and sWGA affinities were demonstrated in the Golgi zone of columnar cells. These affinities decreased in the cold-treated groups, especially in the Golgi zone of columnar cells. The affinities with DBA, RCA-1, sWGA and BSL-1 was demonstrated in the goblet cells of the duodenum, but these affinities except DBA decreased in the cold-treated chipmunks. All lectin affinities except UEA-1 detected in duodenal gland, but cold-treatment induced a decrease of these affinities. The changes in amount and properties of GC in the present experimental model for hibernation may be due to the different intestinal environment associated with food intake. However, the present experimental model for hibernation, especially 9 months cold-treated chipmunks, stills need to be demonstrated during seasonal hibernation in the wild.

Fine Structure and Glycoconjugate Complex Pattern of the Rat Vaginal Epithelium during Pregnancy / 대한해부학회지

The present study is designed to study the light and electron microscopic structure of the rat vaginal epithelium during pregnancy. Furthermore, lectin histochemistry is used to know the changes of the terminal sugar of the glycoconjugate in the vaginal epithelium during pregnancy. The 0 day of pregnacy is defined as the day of presence of sperm in a vaginal smear. At 0 day of pregnancy, most of cells are flat in morphology except basal cell. Lightly-stained superficial cells had few cell organelles, and all the other cells had many intermediate filament bundles, microvilli-like processes and desmosomes. During pregnancy, the thickness of the vaginal epithelium was increased. The morphology of the mucous cells are changed from a cuboidal shape to a columnar one. The intermediate filament bundles are decreased in the mucous cell after first week of pregnancy. Lectin histochemistry showed the presence of alpha-L-fucose, alpha-D-galactose, beta(1, 4)-N-acetylglucosamine, alpha-D-N-acetylgalactosamine and galactosyl-beta(1, 4)-N-acetylglucosamine in the mucous cells. The basal cells also contained the same terminal sugars except galactosyl-beta(1, 4)-N-acetylglucosamine. Approaching to the birthday, the thickening of the mucous layer of the vaginal epithelium suggests that the mucous containing several glycoconjugates may play an important role to make the appropriate environment in the vaginal lumen during pregnancy and parturition.

Lectin Histochemistry on the Surface Mucous Cells, Mucous Neck Cells and Chief Cells in the Gastric Mucosa of Developing Rat / 체질인류학회지

To localize glycoconjugates of surface mucous cells, mucous neck cells and chief cells in the developing rat, nine of biotinylated lectin(SBA, DBA, PNA, BSL-1, RCA-1, sWGA, UEA-1, Con A and LCA) were applied with ABC method. In the surface and gastric pit epithelium of body of the stomach, DBA affinity was not demonstrated. Although Con A and LCA affinity were slightly increased after birth, these affinities with RCA-1 and sWGA maintained constantly from fetal to adult rat. And UEA-1 affinity gradually increased from the end of suckling period. BSL-1 and PNA affinity showed a tendency to decrease and was not observed in most cells from the suckling and weanling period respectively. In the gastric gland proper, mucous neck cells and chief cells were not distinguished until the early weanling period. All affinities examined except DBA and BSL-1 were observed and increased in the gland of postnatal rat. With the approach of weanling period, more intense affinity for PNA, RCA-1, sWGA and UEA-1 were found on lower portion of the gastric gland proper and more intense affinity for SBA on upper portion. The mucous neck cells showed a similar affinities as gastric gland proper from the weanling period and two affinities for PNA and Con A were detected in the chief cell.

The Properties of Glycoconjugates of Apoptotic Cell in the Rat Accessory Sex Gland after Castration / 대한해부학회지

The present study was carried out to investigate the structure and the glycoconjugate properties of the apoptotic cells in the rat accessory sex glands (prostate gland, seminal vesicle and coagulating gland) after castration. After identifying the apoptotic cells by TUNEL method, the structure and the glycoconjugate property of these cells was observed with the light and electron microscopes, using nine kinds of lectins (PSA, UEA I, GSL I B4, ECL, DBA, SBA, DSL, GSL II or WGA). And also, the glycoconjugate properties of the apoptotic cells originated from the prostate epithelial cell culture were investigated. The apoptotic cells have condensed and fragmented nucleus, and also have degenerated and condensed cytoplasm. The numerous apoptotic cells were observed in the accessory sex gland at 2nd day after castration, and in the cultured prostate epithelial cell which were grown in the medium lacking growth factors for 12 hours. The cytoplasm and nucleus of the apoptotic cells induced by castration showed positive reaction with PSA, UEA I, SBA, DSL and WGA, which indicate apoptotic cells have the glycoconjugates contain alpha-D-mannose, alpha-L-fucose, terminal beta-N-acetyl-D-galactosamine and internal beta-1, 4-N-acetyl-D-glucosamine oligomer. But normal epithelial cells of the accessory sex glands showed different glycoconjugate property from the apoptotic cells. These facts suggest that the glycoconjugate property was changed by apoptosis. The apoptotic cells induced by culture showed positive reactions with the nine different lectins.

Lectin Binding Pattern of the Duodenal Mucosa in the Developing Rat / 대한해부학회지

For demonstrating the changes of lectin biding pattern in the developing rat, nine biotinylated lectin were applied with ABC method. The affinities for SBA, PNA, RCA-1, sWGA, and Con A were observed on 15 day fetal rat, and an additional UEA-1 affinty on 17 day fetal rat was detected. From the next developing rats, lectin binding pattern was signicantly altered and these changes were greater in suckling rats than others. The notable changes of the duodenal mucosa in developing rats were as follows : A new affinities for SBA, sWGA and UEA-1 in the villous columnar cells and PNA, RCA-1, sWGA and Con A in the crypt columnar cells were detected from suckling rats. The SBA, PNA, BSL-1, RCA-1, sWGA and UEA-1 affinities in the Golgi zone of villous columnar cells showed a tendency to increase from the suckling rats, and a new affinities for SBA, PNA, BSL-1, RCA-1 and sWGA in that of crypt columnar cells revealed from same rats. All lectin affinities used except DBA and Con A were observed in the brush border and maintained a higher level until adults, however, no BSL-1 affinity was detected from the weaning rats. The UEA-1 affinity of goblet cells was detected from 19 day fetal rat and not observed from the weaning rats. And the affinity for DBA and SBA of the goblet cells was demonstrated from the suckling and weaning rats respectively. All lectin affinities examined were observed in the duodenal gland and increased from the suckling rats.

Distribution of Glycoconjugates During Wound Healing After Argon Laser Photocoagulation in Pigmented Rabbit Retina

Lectin is a non-immunological glycoprotein and binds specifically to carbohydrate terminals in tissue. Lectin histochemistry using 10 different biotinylated lectins was performed to investigate the effects on thirty-two pigmented rabbit retinas during wound healing. The results are as follows: 1) In normal retina. a) WGA, RCA I, and LCA were bound to the internal limiting membrane. b) WGA, RCA I, LCA, and PNA were bound to the photoreceptor layer. c) WGA, RCA I, LCA, SJA, ConA and BSL I were bound to the basal side of retinal pigment epithelium. d) PNA was bound to cone cell only. e) SBA, DBA, and UEA I didn't bind to any layers of retina. 2) In photocoagulated wound. One day after photocoagulation WGA, LCA and RCA I began to show increased reaction. At 3 and 5 days these lectins sustained reactivity. At 7 days increased reactivity began to decrease or disappear from wound. Macrophages had positive reaction to BSL I, WGA, LCA, and RCA I. In conclusion these results indicate that a-mannose, a glucose, a, beta-galactose, N-acetylglucosamine, and N-acetylneuramic acid are present in glycoconjugates of normal rabbit neural retina. It seems that some glycoconjugates may be related to vitreoretinal, retinal and chorioretinal adhesion in normnal retinal, and after argon laser photocoagulation. WGA-binding, LCA-binding and RCA I-binding glycoconjugates may play a part in cell adhesion during early wound healing.

Glycoconjugate glycan and its association with breast cancer / 中国药理学通报

Breast cancer has the highest incidence of gynecological tumors. Investigating into pathogenesis of breast cancer resulting from the change of glycoconjugate glycan has become the hotspot in disease glycomics. The diversified situation of glycoconjugate glycan and its association with breast cancer are reviewed and some issues are also discussed.