Sensitive method for the determination of pulmonary surfactant phospholipid/sphingomyelin ratio in human amniotic fluids for the diagnosis of respiratory distress syndrome by thin-layer chromatography-immunostaining

By TLC-immunostaining with the monoclonal antibody VJ-41, which preferentially reacted with sphingomyelin (Sm) and disaturated fatty acid-containing phosphatidyl choline (DSPC), Sm and surfactant phospholipid dipalmitoyl PC were only detected in the lipid extracts from human amniotic fluid. The method was useful in the selective and simultaneous determination of surfactant phospholipid and Sm concentrations in the amniotic fluids to determine the level of maturity of the lungs of the fetus. By measuring the density of spots visualized by TLC-immunostaining, we detected Sm at a sensitivity two times higher than that for dipalmitoyl PC using the antibody. More than 50 ng of dipalmitoyl PC and Sm was detected on the same TLC plate and the standard curves were linear up to 1 microgram of phospholipids. The method was applied to determine the surfactant phospholipid/Sm ratio in 20 microliter of the amniotic fluids obtained at delivery, and the amniotic fluids from the women who delivered a baby suffering from respiratory distress syndrome (RDS) were easily discriminated from the normal amniotic fluids. In an analysis of 200 microliter of amniotic fluids from 4 RDS cases and 16 normal baby cases, the mean DSPC/Sm ratios were 0.97 +/- 0.53 and 5.75 +/- 1.29, respectively.

Developmental changes of neutral glycosphingolipids as receptors for pulmonary surfactant protein SP-A in the alveolar epithelium of murine lung

A dramatic change in the glycosphingolipid composition in murine lung occurred between 1 day and 1 week after birth. GlcCer and LacCer were the predominant neutral glycosphingolipids prenatally and 1 day after birth, and the concentrations of globo- and ganglio-series glycosphingolipids increased abruptly from 1 week after birth, reaching maxima at 2-3 weeks. To explore the functional significance of the change, we examined the role of neutral glycosphingolipids as receptors for the murine pulmonary surfactant protein, SP-A, and found that SP-A bound to LacCer, Gg3Cer, and Gg1Cer, but not to Gb3Cer, Gb4Cer, IV3GalNAc alpha-Gb4Cer, sulfatide, or several gangliosides. On TLC-blotting with 125I-labeled SP-A, the binding of SP-A to Gg3Cer and Gg4Cer was 5 times higher than that to LacCer, and on immunohistochemical staining Gg4Cer and Gg3Cer was mainly observed in the alveolar epithelium. Thus, the capacity to retain SP-A of glycolipid receptors per gram dry weight of lung at 1 week after birth was 1.6 times higher than that at 1 day after birth, and reached a maximum 3 weeks after birth. These findings suggest that the enhanced synthesis of the ganglio-series neutral glycosphingolipids 1 week after birth results in an increase in the binding capacity for SP-A on the epithelial cell surface of alveoli.

Selective reduction in alpha-hydroxypalmitic acid-containing sphingomyelin and concurrent increase in hydroxylated ceramides in murine skin tumors induced by an initiation-promotion regimen

The sphingomyelin cycle is activated to accumulate ceramides in the process of epidermal differentiation. We found that sphingomyelin in the epidermis of 4 different murine strains gave three bands on TLC, the lower band containing alpha-hydroxypalmitic acid (C16h:0(alpha)). However, in the papillomas induced in the skin of SENCAR and SSIN mice by initiation with 7,12-dimethylbenz[a]anthracene followed by promotion with 12-O-tetradecanoylphorbol acetate, the concentration of C16h:0(alpha)-containing sphingomyelin was selectively diminished with a concomitant increase in the concentrations of the ceramides containing alpha-hydroxy fatty acids. These findings indicate a possible involvement of the selective hydrolysis of alpha-hydroxy fatty acid-containing sphingomyelin in the process of tumorigenesis in mouse skin.

Role of sulfatides in adhesion of Helicobacter pylori to gastric cancer cells

We have demonstrated that clinical isolates of Helicobacter pylori preferentially bind to sulfatides (I3SO3-GalCer) and GM3 gangliosides (II3NeuAcLacCer), two predominant acidic glycosphingolipids in the human gastric mucosa, on thin-layer chromatography plates. However, it has not yet been clarified that these glycospingolipids truly serve as adhesion receptors for H. pylori in live cells. In this study, we used a gastric cancer cell line, KATO III, as a cellular model of H. pylori adhesion and examined the role of sulfatides in attachment. The adhesion of H. pylori (i.e., a standard strain of H. pylori, NCTC 11637) to KATO III cells and the effects of various substances on this adhesion were monitored and semiquantitated by flow cytometric analysis. Sulfated glycoconjugates, such as heparin and gastric mucin, significantly inhibited H. pylori adhesion to KATO III cells. Membrane preparations from KATO III cells strongly inhibited this adhesion. In the membrane preparations, sulfatides were present as a major acidic glycosphinoglipid. With the exception of sulfatides, no distinct adhesion of H. pylori to glycospingolipids from KATO III cells were observed. Moreover, H. pylori did not bind to any membrane proteins of KATO III cells. Finally, a monoclonal anti-sulfatide antibody markedly reduced H. pylori adhesion to KATO III cells. These results suggest that sulfatides, and possibly related sulfated compounds, serve as a major receptor for cell adhesion by H. pylori.

IgM natural antibody against an asialo-oligosaccharide, gangliotetraose (Gg4), sensitizes HIV-I infected cells for cytolysis by homologous complement

Although cells are usually resistant to homologous complement, the IgM antibody against gangliotetraose (Gg4), an asialo-oligosaccharide of GM1, was found to cause cytolysis of HIV-1 infected cells by homologous complement. Due to its size, IgM might enable the initiation of the complement cascade away from membrane complement inhibitors such as decay accelerating factor and membrane cofactor protein. Furthermore, HRF20 (CD59), which restricts formation of membrane attack complexes (MAC) of complement on homologous cell membranes, was significantly decreased on HIV-infected cells and therefore formation of MAC on cell membranes would be facilitated. IgM antibodies reactive with HIV-infected cells could result in the elimination of infected cells via complement-mediated cytolysis in HIV-infected patients, since all tested sera from HIV-positive hemophilia patients who have survived for >12 years contained IgM antibody activity against HIV-infected MOLT4 cells in a preliminary experiment. Therefore, administration of IgM antibodies reactive with HIV-infected cells may be effective in the treatment of HIV carriers.

Significantly high synthetic activities of cholesterol sulfate in the nasal, oral and tracheal mucosae of guinea pigs

Cholesterol sulfate (CS) is widely distributed in mammalian tissues and various physiological roles for it have been suggested, but the presence of CS in the nasal tissues has not yet been reported. This is the first report in which the CS content and the activity of its regulatory enzymes, cholesterol sulfotransferase (CST) and cholesterol sulfate sulfatase (CSS), in the nasal mucosa of the guinea pig were examined and compared with those in the oral and tracheal mucosae. The highest concentration of CS was detected in the oral mucosa and the second highest in the nasal mucosa. The activity of CST was also highest in the oral mucosa and the second highest in the nasal mucosa. On the other hand, that of CSS was highest in the tracheal mucosa. The accumulation of CS is assumed to be related to squamous differentiation, because the activity of transglutaminase type 1 in the nasal, oral and tracheal mucosae coincided with the order of the concentration of CS in those tissues. These results suggested that the accumulation of CS is correlated with the morphological differences between the oral stratified squamous and the nasal or tracheal pseudostratified epithelium, and furthermore that the nasal epithelium is more susceptible to squamous metaplasia than the tracheal epithelium in the guinea pig.

Alteration in the reactivity of sphingomyelin in mitogen-stimulated lymphocytes

The antigens for a monoclonal antibody, VJ-41, established by alloimmunization of B10.A(3R) mice with lymphocytes from B10.A(5R) mice and screening of its reactivity toward Con A-stimulated human T lymphocytes, were found to be phosphorylcholine-containing ceramides (sphingomyelin) and disaturated fatty acyl glycerol (phosphatidyl-choline, PC), but neither deacylated sphingomyelin nor unsaturated fatty acid-containing PC reacted with the antibody. Although the reactivity of disaturated fatty acyl PC increased with increasing chain length, that of sphingomyelin was stronger than that of di-20:0-PC. The binding of the antibody to Con A-stimulated lymphocytes was inhibited by sphingomyelin-containing liposomes, but not by di-18:0-PC-containing ones, and the concentration of sphingomyelin in Con A-stimulated human T-lymphocytes was the same as that in non-stimulated ones, indicating that the reactivity of sphingomyelin in lymphocytes is altered by Con A-stimulation.

Enhancement of adhesive property of epithelial cell line Mm2T by culture in the presence of methylated vitamin B12

A thymic epithelial cell line Mm2T was cultured in a medium containing a high concentration (100 micrograms/ml) of methylated vitamin B12 (CH3-B12). After 19 days, cells were found to have a flat phenotype, to have lost the floating cells which were observed in the control cells at the confluent stage, and to have acquired a resistance to trypsin. However, treatment of the CH3-B12-treated cells with EDTA resulted in a dissociation of cell-to-cell contact and reaggregation was achieved by addition of Ca2+, indicating the involvement of Ca2+ ion in cell-to-cell contact. Electron microscopic analyses revealed that the CH3-B12-treated cells were nearly square in their vertical section, which was in contrast to the dome-shaped feature of the control cells, and their cell-to-cell contact area was significantly widespread, as compared to those of the control, indicating that Mm2T cells acquires an adhesive property by treatment with CH3-B12. Biochemical analyses of both cells indicated that the concentration of glucosylceramide in the CH3-B12-treated cells was higher than that of the control. Free glucose characteristically inhibited the reattachment of cells dissociated with EDTA, suggesting the involvement of glucose in the cell-to-cell adhesion of CH3-B12-treated cells. In addition, WGA-binding glycoconjugates were intensely observed in the boundary region of CH3-B12-treated cells by immunohistochemical staining, but not in that of the control cells. It is suggested that CH3-B12 may affect the morphological alteration of Mm2T by enhancing cell adhesion through elevated expression of the C-type lectin.

Characteristic expression of GD1 alpha-ganglioside during lactation in murine mammary gland

Cellular proliferation and differentiation in mammary gland are known to be significantly altered during pregnancy and subsequent lactation. To characterize the different stages of mammary gland during pregnancy and lactation, we analyzed the glycosphingolipid compositions in the mammary gland of DDD and ICR mice at several periods of pregnancy and lactation, and found that the ganglioside composition, but not neutral glycosphingolipids, was characteristically altered during the pregnancy and lactation periods. The concentrations of acidic glycosphingolipids, I3SO3-GalCer 1, GM3, GM1a, GM1b and GD1a, were reduced during the course of pregnancy and lactation. GD1 alpha (III6NeuAc alpha,IV3NeuAc alpha-Gg4Cer) was first detected at the mid-period of pregnancy (12 days of pregnancy for ICR mice), increased in concentration at the late-period of pregnancy (GD1 alpha concentration was 100 times higher at 18 days than that at 12 days of pregnancy), and was a major ganglioside comprising 60-70% of the total lipid-bound sialic acid in the mammary gland of ICR and DDD mice at the lactation period, indicating that expression of GD1 alpha is associated with the lactating mammary gland of mice. In fact, GD1 alpha was highly concentrated in the milk fat globule, in which it was a major component.

Programmed expression of cholesterol sulfotransferase and transglutaminase during epidermal differentiation of murine skin development

To clarify the role of cholesterol sulfate (CS) in the process of epidermal differentiation in vivo, we investigated the concentration of CS and the specific activities of cholesterol sulfotransferase (CST), cholesterol sulfate sulfatase (CS sulfatase) and epidermal transglutaminase (ETG) in murine skin in the pre- and postnatal periods. In the skin at day 14 of gestation, CS was not detected with TLC and the specific activities of all the enzymes were low. However, concomitant with the formation of the multilayered structure of the epidermis (at day 16), the specific activities of CST steeply increased. Although the insoluble CS sulfatase in the microsomal fraction remained at a relatively constant level, the soluble CST in the cytosol fraction showed a 6-fold increase from day 14 to day 16, and the activity decreased continuously in the following period, reaching one forty-sixth of the maximum level at 4-months-old mice. Reflected by the increase in activity, CS was detected in fetal skin at day 15, and the concentration in epidermis significantly increased during the gestation period, reaching maximum level at day 17. Furthermore, the changes in the concentration of cholesterol sulfate were identical with those of N-(O-linoleoyl)-omega-hydroxy fatty acyl sphingosine and its glucosyl derivative in the epidermis. On the other hand, the specific activity of ETG increased after birth. Thus, the activation of CST and ETG was shown to occur separately in association with the formation of the multilayered structure and thickening of the stratum corneum, respectively.

Cholesterol sulfate, a novel activator for the eta isoform of protein kinase C

Activity of protein kinase C depends on the interaction with polar head-groups of two membrane lipids, i.e., phosphatidylserine and diacylglycerol. In the present study, we demonstrated a novel activation mechanism of the eta isoform of protein kinase C (nPKC eta), which is predominantly expressed in epithelial tissues in close association with epithelial differentiation. We found that the nPKC eta was activated by cholesterol sulfate, a metabolite of cholesterol formed during squamous differentiation. This activation was greater than that by phosphatidylserine plus phorbol ester; the Vmax for the activation by cholesterol sulfate was 3.6 times that by phosphatidylserine plus phorbol ester, while Kms were almost equal. In the presence of cholesterol sulfate, phorbol ester only weakly enhanced the activity of nPKC eta. Activation of nPKC eta by cholesterol sulfate was further demonstrated by autophosphorylation of the kinase molecule. However, the alpha and delta isoforms of protein kinase C were not activated by cholesterol sulfate. The present observation affords a new insight into a signal transduction pathway of squamous differentiation.

Pseudopregnancy-dependent accumulation of cholesterol sulfate due to up-regulation of cholesterol sulfotransferase and concurrent down-regulation of cholesterol sulfate sulfatase in the uterine endometria of rabbits

The uterine endometria of rabbits induced into pseudopregnancy by intramuscular injection of 17 beta-estradiol, followed by intravenous injection of human chorionic gonadotropin, expressed cholesterol sulfate at a significantly high concentration. The highest concentration of cholesterol sulfate was observed 4 days after the injection of gonadotropin for formation of the corpus luteum, being 10 times higher than that in nonpregnant endometria, and 15.2% of the total cholesterol in the endometrium was converted to the sulfated form, whose percentage in nonpregnant endometrium was 3.2%. However, no significant change in the concentration of gangliosides was observed during the period of pseudopregnancy. In the pseudopregnant endometria, the activity of cholesterol sulfotransferase, a cytosolic thiol enzyme, was increased thirtyfold over that in the nonpregnant endometria, whereas cholesterol sulfate sulfatase, a microsomal enzyme, exhibited approximately one-tenth of the activity in nonpregnant endometria. Arylsulfatase C, but not arylsulfatases A and B, exhibited the same change in activity as cholesterol sulfate sulfatase. Thus, the striking increase in cholesterol sulfate after induction of pseudopregnancy was found to be due to the activation of cholesterol sulfotransferase and the simultaneous inhibition of cholesterol sulfate sulfatase.

Unique T cell differentiation markers: gangliosides with cholera toxin receptor activity on murine fetal thymocytes

Cholera toxin B subunit receptors (CTBR; gangliosides GM1a and GM1b-GalNAc-Gal) and GM1b-type gangliosides were examined during T cell development in BALB/c mice by FACS or TLC immunostaining. Sixty-two percent of CD4-8- early fetal thymocytes express CTBR [58% low affinity (GM1a+), 4% high affinity (GM1a2+)] at 13 days gestation (Day 13); GM1a2+ was expressed preferentially on Thy-1+ fetal thymocytes after Day 13. GM1a2+ Thy-1+ cells increased from 4% on Day 13 to 95% on Day 17. Surface GM1a2+ decreased beginning on Day 15 while GM1b-GalNAc-Gal (and CD4 and CD8) increased. GM1b-type+ cells increased from 8% on Day 13 to 51% on Day 17 and then decreased to 16% at 4 weeks; few asialo GM1+ cells (< 5%) are seen during gestation. Thus, synthesis of GM1a- and GM1b-type series was active until Days 15 and 17, respectively, and then was suppressed; GM1b-GalNAc-Gal was synthesized from GM1b following Gestational Day 15. GM1a- and GM1b-type identify immature T cells in mice, while GM1b-GalNAc-Gal identifies mature T cells.

Hormone-dependent enhancement in binding of oto- and nephrotoxic aminoglycoside antibiotics

Intraperitoneal administration of gentamicin (40 mg/ml) to the guinea pig is known to cause damage of the tissue of the kidneys and auditory organs. By indirect immunohistochemical staining with anti-gentamicin antiserum, those cells with high affinity to gentamicin in the auditory organs and kidneys were the hair cells in the cochlea and the epithelial cells in the renal tubules. The concentrations of gentamicin in the serum and perilymph of the guinea pig with tissue damage were found to be 2 and 0.6 mg/ml at the maximal levels, respectively, by high performance liquid chromatography. The same concentration of gentamicin, 2 mg/ml, also inhibited cell growth and resulted in cell damage of the renal tubule-derived cell lines, JTC-12 and MDCK. Among the antibiotics examined, i.e. streptomycin, gentamicin, fradiomycin and kanamycin, gentamicin showed the strongest effect on growth inhibition of the renal tubule-derived cells, when these cells were cultured in a medium with 5% fetal calf serum. Although the number of JTC-12 cells in the medium without fetal calf serum remained the same for a week, even with the addition of either gentamicin (0.5 mg/ml) or parathyroid hormone (2 mM) the coadministration of gentamicin and parathyroid hormone resulted in a loss of cells due to cellular death, and the amount of gentamicin bound onto the cells cultured with gentamicin plus parathyroid hormone was significantly higher than that with gentamicin alone. These results indicate that the expression of the receptor for gentamicin on the cell surface is greatly enhanced by hormonal stimulation.

Compensatory occurrence of IV2Fucalpha,II3NeuAcalpha-Gg4Cer and human fetal antigen Lc4Cer in small cell carcinomas of the human lung

By means of a thin-layer chromatography immunostaining procedure involving a human monoclonal anti-Lc4Cer antibody, which was established by hybridizing murine myeloma cells and human lymphocytes from a cancer patient, Lc4Cer was proven to be a fetal antigen of human lung and to be a cancer-related antigen in small cell carcinomas of human lung, but not of other lung cancers, i.e., large cell carcinomas, adenocarcinomas, and squamous carcinomas. With the simultaneous detection of IV2Fuc alpha,II3NeuAc alpha-Gg4Cer with rabbit anti-IV2Fuc alpha,II3NeuAc alpha-Gg4Cer antiserum, the expression of Lc4Cer and IV2Fuc alpha,II3NeuAc alpha-Gg4Cer was found to be compensatory and, consequently, small cell lung carcinomas could be classified into Lc4Cer- and IV2Fuc alpha,II3NeuAc alpha-Gg4Cer-expressing types, L-SCLC and F-SCLC, respectively, which were detected in four and 27 of 31 patients' tissues and in one and three of four nude mouse-transplanted small cell lung carcinoma tissues, respectively. The compensatory expression of Lc4Cer and IV2Fuc alpha,II3NeuAc alpha-Gg4Cer in small cell carcinomas indicated that different metabolic pathways for glycosphingolipids were activated to give the distinct glycosphingolipid compositions in the two types of small cell lung carcinomas.

Luteal phase-characteristic induction of I3SO3-GalCer in human cervical epithelia and uterine endometria, and follicular phase-characteristic formation of a ganglioside-derived negative charge gradient in different regions of fallopian tubes

In a series of experiments on the hormone-dependent molecular alteration in the human genital tract during the menstrual cycle, we focused our attention on a change in the negative charge due to the sulfuric acid- and sialic acid-containing glycosphingolipids. Although a ganglioside-derived negative charge was maintained in the cervical epithelia and uterine endometria at a relatively constant concentration throughout the luteal and follicular phases, I3SO3GalCer in both tissues characteristically increased in the luteal phase, indicating that the synthesis of I3SO3-GalCer in both tissues is associated with the menstrual cycle. However, I3SO3-GalCer in mucosae of the fallopian tubes in both phases was present in a concentration similar to that in the uterine endometrium in the luteal phase, and the change in the concentration did not associated with the menstrual cycle. On the other hand, although the concentrations of I3SO3-GalCer and II3NeuAc-LacCer, a major ganglioside, were similar in different regions, that is, the isthmus, ampulla and fimbriae of the fallopian tubes in the luteal phase, II3NeuAc-LacCer was present in a gradually increasing concentration from the isthmus to the fimbriae in the follicular phase, giving a gradually decreasing ratio of I3SO3GalCer to ganglioside from the uterus to the fimbriae. These findings indicate that the metabolism of sulfo- and sialoglycosphingolipids in the human genital tract is strictly controlled by estrogen and progesterone.

Immunoglobulin variable region sequences of two human monoclonal antibodies directed to an onco-developmental carbohydrate antigen, lactotetraosylceramide (LcOse4Cer)

A human monoclonal antibody, 11-50, was generated and was shown to recognize an onco-developmental carbohydrate antigen, LcOse4Cer. The isotype of this antibody was IgM, lambda, similar to the previously known human anti-LcOse4 antibodies, such as IgMWOO and HMST-1. We raised a murine anti-idiotypic antibody G3 (IgG1, kappa) against 11-50, and tested its reactivity towards the affinity purified human polyclonal anti-LcOse4 antibodies prepared from pooled human sera using a Gal beta 1-->3GlcNAc beta-immobilized column. The results indicated that at least a part of the human polyclonal anti-LcOse4 antibodies shared the G3 idiotype with 11-50. We further analyzed the sequence of variable regions of the two anti-LcOse4 antibodies, 11-50 and HMST-1. Sequence analysis of the heavy chain variable regions indicated that the VH regions of these two antibodies were highly homologous to each other (93.5% at the nucleic acid level), and these antibodies utilized the germline genes VH1.9III and hv3005f3 as the VH segments, which are closely related germline genes of the VHIII family. It was noted that these germline VH genes are frequently utilized in fetal B cells. The JH region of both antibodies was encoded by the JH4 gene. For the light chain, the V lambda segments of the two antibodies were 96.3% homologous to each other at the nucleic acid level. The V lambda segments of both antibodies showed the highest homology to the rearranged V lambda gene called V lambda II.DS among reported V lambda genes, while the exact germline V lambda genes encoding the two antibodies were not yet registered in available sequence databanks. The amino acid sequences of the J lambda segments of both antibodies were identical. These results indicate that the two human antibodies recognizing the onco-developmental carbohydrate antigen Lc4 are encoded by the same or very homologous germline genes.

Systematic analysis of glycosphingolipids in the human gastrointestinal tract: enrichment of sulfatides with hydroxylated longer-chain fatty acids in the gastric and duodenal mucosa

The composition of the glycosphingolipids of the human gastrointestinal tract was studied. The major neutral glycosphingolipids were ceramide monohexosides (e.g., GalCer, GlcCer), LacCer, Gb3Cer, Gb4Cer and more polar ones with more than four sugars, whereas neither Gg3Cer nor Gg4Cer were present. The acidic glycosphingolipids consisted of sulfatides and gangliosides such as GM3, GM1, GD3 and GD1a. Also a large amount of sulfatides was found in the gastric mucosa and duodenum. The concentrations of sulfatides in the fundic mucosa, antral mucosa and duodenum amounted to 416.0, 933.8 and 682.9 nmol/g of dry weight, respectively, exceeding those in the gastric mucosa and kidney of other mammals. The major molecular species of the sulfatides were identified as I3SO3-GalCer with hydroxylated longer-chain fatty acids based on the analyses by gas-liquid chromatography and negative ion fast-atom bombardment mass spectrometry. In contrast, gangliosides in these regions showed a tendency to be lower than sulfatides, and the molar ratios of sulfatides to gangliosides were about 2.0, whereas those in other parts were less than 0.5. A high content of sulfatides in the gastric and duodenal mucosa, where mucosa is easily insulted by acid, pepsin and bile salts, may be closely related to their roles in mucosal protection.

Characteristic alteration in the concentration of IV 3NeuAc alpha-nLc4Cer in the villi of human placenta during the gestational period

A study on the ganglioside composition in the villi isolated from human placenta at various gestational periods was carried out by conventional procedures including thin-layer chromatography (TLC), TLC-immunostaining, negative ion fast-atom bombardment mass spectrometry (FABMS) and exoglycosidase treatment. The major gangliosides in the villi were II3 NeuAc-LacCer (GM3) and IV3NeuAc alpha-nLc4Cer, comprising 60-70% of the total gangliosides. The concentration of IV3NeuAc alpha-nLc4Cer per gram dry weight of tissue in the villi was found to be gradually decreased from the early to the late gestational period and the molecule with 2-hydroxy fatty acids was undetectable after 20 weeks of the gestational period. However, no significant correlation between the concentration of GM3 and the gestational periods was observed. Thus the characteristic alteration in the concentration of IV3NauAc alpha-nLc4Cer in the villi might be related to various functions of human placental villi during the gestational period.

Human cervical epidermal carcinoma-associated intracellular localization of glycosphingolipid with blood group A type 3 chain

A monoclonal antibody, MRG-1, was produced by immunizing a mouse with a human ovarian mucinous cyst adenocarcinoma-derived cell line, RMUG-L. By immunohistochemical staining, the antigen was found to be exclusively localized in the intracellular structures of the cells used as the antigen and of the epithelial cells in normal human cervical glands. However, although the antigen was predominantly detected in the plasma membrane and the intercellular structure of the middle layer of normal human cervical squamous epithelium (92%), it was also contained in the intracellular structure of cervical epidermal carcinoma at a high frequency (80%). The striking difference in the distribution of the MRG-1 antigen between normal and cancerous tissues was found to be a cervical carcinoma-associated phenomenon and a useful tumor marker for immunohistochemical examination. Since the antigen was found to be of a blood group A-related nature by immunohistochemical staining of the tissues and to be a glycosphingolipid, it was purified from human erythrocytes of blood group A, and the structure was concluded to be GalNAc alpha 1-3Gal(2-1 alpha Fuc)beta 1-3GalNAc alpha 1-3Gal(2-1 alpha Fuc)-beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1' Cer, blood group A type 3 chain-containing glycosphingolipid, by NMR, negative ion FABMS and permethylation analysis. In the subcellular localization analysis of the antigen, type 3-A glycosphingolipid antigen was detected in the Golgi body and the microsomes of RMUG-L cells, and the distribution coincided with the finding by immunohistochemical staining. In addition, in cervical epidermal carcinoma, although the blood group A, mainly type 2-A chain, was localized in the plasma membrane and the intercellular structure, the blood group A type 3 chain was selectively found in the perinuclear structure. Also, the blood group A type 3 chain in cervical dysplasia as well as that in normal cervix was predominant in the plasma membrane. Thus, the selective intracellular localization of blood group A type 3 chain was a phenomenon characteristic of cervical epidermal carcinoma and the carcinoma in situ.

Structural characteristics of the ceramides of neutral glycosphingolipids in the human female genital tract--their menstrual cycle-associated change in the cervical epithelium and uterine endometrium, and their dissociation in the mucosa of the fallopian tube with the menstrual cycle

In human cervical epithelium, uterine endometrium, and mucosa of the fallopian tubes, neutral glycosphingolipids were exclusively represented by the globo-series glycosphingolipids, such as CMH, LacCer, Gb3Cer and Gb4Cer, but the molecular species of their ceramide moieties were characteristically altered in the cervical epithelium and uterine endometrium during the menstrual cycle. Individual neutral glycosphingolipids in the cervical epithelium and the uterine endometrium at the follicular phase gave two bands on TLC, whereas those at the luteal phase displayed three bands, the third being the lower migrating one. Neutral glycosphingolipids migrating to the same positions as these lower-migrating bands were constantly detected in the mucosa of the fallopian tubes, independent of the menstrual cycle. The lower-migrating bands for the cervical epithelium and the uterine endometrium at the luteal phase were due to molecules mainly constructed of phytosphingosine with alpha-hydroxy fatty acids having chain lengths of 18-24 and 4-sphingenine with alpha-hydroxy fatty acids having chain lengths of 16-22, whereas those in the mucosa of the fallopian tubes were exclusively N-alpha-hydroxypalmitoyl 4-sphingenine.

Common phenotypic expression of gangliosides GM3 and GD3 in normal human tissues and neoplastic skin lesions

The expression of gangliosides in non-malignant tissues (epidermis and pigmented nevus) and neoplastic lesions (melanoma, squamous cell carcinoma [SCC] and basal cell carcinoma [BCS]) of the human skin was analyzed immunohistochemically and biochemically to characterize the features associated with malignancy. Immunohistochemical staining with an anti-II3NeuAc-LacCer (GM3) monoclonal antibody (M2590 mAb) and an anti-II3(NeuAc)2-LacCer (GD3) mAb (R24) showed the expression of the gangliosides GM3 and GD3 to vary among the different tissues. M2590 clearly stained epidermal keratinocytes and the tumor cells of BCC and SCC, and strongly stained melanocytes and melanoma cells. In contrast, R24 did not stain epidermal keratinocytes and only faintly stained SCC cells, while it clearly stained BCC cells, and intensely stained melanocytes and melanoma cells. GM3 showed a similar level of staining among the tissue specimens, while the level of GD3 staining was quite variable among the tumor specimens. Biochemical analysis by thin-layer chromatography (TLC) with resorcinol staining and TLC immunostaining with either M2590 or R24 showed both GM3 and GD3 to be commonly expressed by both the normal and malignant skin tissues, including SCC. There was no close correlation between the intensity of immunohistochemical staining and the biochemically detected amounts of these gangliosides. This may have been partly due to the so-called cryptic expression of cell membrane gangliosides. Our results thus suggest that analysis of the tumor-associated expression of gangliosides requires several methods, since the sensitivity of the methods used may have a considerable effect on the diagnostic value of gangliosides as skin cancer markers.

Developmental changes of fucosylated glycoconjugates in rabbit dorsal root ganglia

Developmental changes of the fucosylated glycoconjugates in the dorsal root ganglia (DRG) of the rabbit were investigated histochemically using anti-fucosyl GM1 antibody and Ulex europaeus agglutinin 1 (UEA-1) lectin. Neither anti-fucosyl GM1 antibody nor UEA-1 lectin bound to the neural tubes or to the neural crest on embryonic day 14 (E14). Anti-fucosyl GM1 antibody binds diffusely to the DRG of E25. Large neurons unreactive with anti-fucosyl GM1 antibody appeared at 1 month and increased within 6 months after birth. Schwann cells immunoreactive with anti-fucosyl GM1 antibody came to be limited to the satellite cells surrounding the positive neurons. No staining with UEA-1 lectin was observed in the DRG of E25. Some small neurons became reactive with UEA-1 lectin within 1 month and remained to be so at 6 months after birth. Schwann cells including satellite cells were unreactive with this lectin. Since fucosyl GM1 was detected in the lipid fraction of DRGs from 1-month-old and 6-month-old rabbits, fucosyl GM1 itself should be the antigen molecule recognized by the anti-fucosyl GM1 antibody. Further study is necessary to elucidate the association between these developmental changes of the fucosylated glycoconjugates in DRG and their possible functional roles.