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S J Kimber

Publications and source records attributed to S J Kimber.

At least 19 recordsLinked to original sources
PubMed1999

Hormonal control of H-type alpha(1-2)fucosyltransferase messenger ribonucleic acid in the mouse uterus.

The H epitope, an alpha(1-2)fucosylated carbohydrate structure, has been implicated in initial attachment of the murine blastocyst to luminal uterine epithelial cells in vitro. In this study, the expression of the H-type alpha(1-2)fucosyltransferase (FUT1) gene was examined in endometrium of mice. Northern blotting of luminal epithelial RNA identified a single 6.2-kilobase transcript. In situ hybridization studies showed a signal for FUT1 mRNA on Days 1-3 of pregnancy in glands and luminal epithelium. The signal diminished by Day 4 and could not be detected on Day 5 of pregnancy. The in situ signal in endometrial epithelia was highest at estrus and metestrus and was absent at diestrus. Estrogen treatment after ovariectomy gave strong FUT1 mRNA expression in epithelia, but with progesterone, progesterone + estrogen, or vehicle, no message could be detected. A semiquantitative reverse transcription-polymerase chain reaction (PCR) analysis of FUT1 mRNA from luminal epithelium generated large amounts of PCR product on Day 1 of pregnancy; this diminished on Days 2, 3, and 4, and the product was barely detectable on Day 5. A kinetic analysis of FUT1 activity on Day 1 of pregnancy suggested a single enzyme with a Michaelis-Menten constant (Km) of 0.29 mM towards phenyl-beta-D-galactoside and of 1.75 mM towards Galbeta(1-3)GalNAc. These results suggest that expression of the H epitope is regulated at the level of FUT1 transcription and that transcription is stimulated by estrogen in the endometrial epithelium.

Animals↗
PubMed1998

Morphological evidence for a morphogenetic field in gastropod mollusc eggs.

Eggs of the marine gastropod Crepidula fornicata examined by confocal imaging of FITC-lectin binding to the surface, and cryoscopic-SEM both reveal a surface architecture of linear structures organized around the animal-vegetal axis, which is spatially related to the anterior-posterior (a-p) axis of the subsequent embryo. A series of structures is also orientated with reference to specific micromere quartets formed during spiral cleavage. Thus, the surface architecture may provide a visible marker for a morphogenetic field which generates the a-p axis and organizes the cleavage pattern. Moreover, this architecture is co-extensive with that found on the vegetal, polar lobe-bearing region of eggs, as described by others, and which varies between gastropod taxa with varied types of body form. Confocal imaging reveals a distinct localization of F-actin to the architecture of the lobe region. However, the integrity of this F-actin is not responsible for the maintenance of the surface architecture. The significance of these findings to our understanding of the generation of diversity within the Gastropoda and general ontogenic mechanisms is discussed.

Actins↗
PubMed1996

Integrins beta 5, beta 3 and alpha v are apically distributed in endometrial epithelium.

Several adhesion molecules have been shown to occur at the surface of endometrial cells. One of these is the integrin alpha v subunit which associates with various beta chains including beta 5. We demonstrate the presence of integrin beta 5 polypeptide in human endometrial epithelial cells throughout the menstrual cycle using immunocytochemistry with monospecific antibodies, and at the mRNA level by thermal amplification from endometrial cDNA. Integrin beta 5 is also found in a population of bone marrow-derived cells. A notable feature of the distribution of the beta 5 subunit in the glandular and luminal epithelium is its apical localization, which may suggest an involvement in implantation. However, no evidence was found for regulated expression of epithelial beta 5. In mouse, the beta 5 subunit is found at both the apical and basal surface of epithelial cells and expression is essentially oestrous cycle-independent. Comparisons are made in both species with the distribution of the alpha v and beta 3 subunits which also localize to the apical epithelium.

Animals↗
PubMed1996

Decidual sialylation shows species-specific differences in the pregnant mouse and rat.

Biotinylated lectins from Sambucus nigra (SNA) and Maackia amurensis (MAA), which bind to alpha 2,6-linked and alpha 2,3-linked sialyl residues, respectively, were used as probes to study glycan terminal modifications associated with decidualization in the uterine stroma of pregnant rats and mice. Binding of lectins from Erythrina cristagalli (ECA), Phaseolus vulgaris (leukoagglutinin, L-PHA), Triticum vulgaris (WGA) and Bandeiraea simplicifolia (BSA-1B4) was also examined. Tissues from rats between day 5 and day 8 of gestation and mice between day 5 and day 7 of gestation were fixed in Bouin's solution and embedded in wax prior to lectin histochemistry. On day 7 in rats and day 6 in mice, there was a marked reduction in the binding of SNA in the subluminal decidua surrounding the implantation site. In rats, MAA binding to enlarged decidual cells around the implantation chamber was increased markedly, but there was no change in mice. In both species there was de novo binding of ECA in the SNA-negative area, suggesting that the loss of alpha 2,6-linked sialyl residues unmasks terminal N-acetyl lactosamine. These findings are consistent with previous evidence of a close structural and functional similarity between the artificially induced deciduoma and true decidua of rats and show identical changes to the glycosylation patterns previously found in differentiating rat deciduoma. In both species, therefore, decidua exhibits regionally specific terminal glycosylation. However, the species-specific expression of alpha 2,3-linked sialyl residues suggests distinct patterns of steroidally modulated sialyl transferase expression.

Animals↗
PubMed1995

Cell adhesion molecules on the oocyte and preimplantation human embryo.

The presence of cell adhesion molecules on human oocytes, early embryos, and pre-hatched blastocysts was examined by indirect immunofluorescence and compared to the distribution found on first trimester villous placenta with the same antibodies. Six integrin subunits (alpha 3, alpha V, beta 1, beta 3, beta 4, beta 5) were observed consistently throughout preimplantation development. Evidence was also obtained for the presence of integrin subunits alpha 2, alpha 4, alpha L, beta 2, and beta 7 on a small number of oocytes. A more restricted developmental analysis of E-cadherin, ICAM-1, NCAM, and VCAM-1 demonstrated that these cell adhesion molecules are also present on oocytes and early embryos. L-selectin was detected on oocytes but was not found on 8-cell embryos. The oocyte and early blastomeres have complex surfaces in which the integrin and CAM families are represented.

Blastocyst↗
PubMed1995

CD44 is expressed throughout pre-implantation human embryo development.

The cell surface glycoprotein CD44 has been demonstrated in a variety of cell types in embryonic and adult tissues. We have established that CD44 is present on human oocytes, cumulus cells, early embryos and pre-hatched blastocysts by indirect immunofluorescence. We have also shown that CD44 is present on 8-11 week placental stroma cells, but not on the trophoblast. These findings demonstrate that CD44 is present throughout preimplantation development, and that down-regulation occurs on the embryonic surface after implantation.

Blastocyst↗
PubMed1995

Expression of carbohydrate antigens in the rat uterus during early pregnancy and after ovariectomy and steroid replacement.

Monoclonal antibodies were used to examine the expression of a number of carbohydrate antigens in the rat endometrial epithelium from day 1 to day 8 of pregnancy and in ovariectomized rats supplemented with ovarian steroids. Carbohydrate antigens based on the Gal beta 1-GlcNAc backbone structure were expressed and some of these (Le(y), Le(x), B antigen) were present at all stages of pregnancy and independent of ovarian steroids. The H-type-2 antigen was stimulated by progesterone and expressed in the sensitized and receptive uterus, but was not detected after implantation or, in ovariectomized rats, in the refractory phase. The H-type-1 antigen, which is stimulated by oestrogen in the mouse, appeared to be stimulated by progesterone in rats. It was expressed throughout the period of pregnancy but maximal expression was found on days 4-5. The histo-blood group A antigen appeared in ovariectomized rats only after treatment with progesterone followed by three daily injections of progesterone and oestrogen, and in the corresponding postimplantation period of pregnant rats. Its appearance corresponded to the loss of detectable H-type-2 antigen. This study shows that the rat endometrial epithelium expresses some carbohydrate antigens not expressed in mice (A and B antigen) or under completely different steroidal regulation (H-type-1). Moreover, the T antigen was expressed on the endometrial epithelium adjacent to decidua on days 7 and 8 of pregnancy, but not in rats given ovarian steroids to mimic the sensitized, receptive or refractory phase. Differences in expression between glandular and luminal epithelial indicated differences in steroidal regulation, as found in mice.

Animals↗
PubMed1994

A new in vitro model of murine mesoderm migration: the role of fibronectin and laminin.

Examination of the factors involved in primary mesodermal migration in the mouse has been complicated by the lack of a suitable in vitro model. We have developed a new culture system using primitive streak stage embryos denuded of primitive endoderm, which allows easy observation and manipulation of the outgrowing cells. The cells migrating away from these explants were shown by immunocytochemistry to express vimentin and an epitope of the I antigen recognised by the antibody C6, both of which are present on the newly emerged mesoderm and not on the embryonic ectoderm in sections of embryos in utero. Conversely, cytokeratin, stage-specific embryonic antigen 1 (SSEA-1), E-cadherin and desmoplakin are expressed by the embryonic ectoderm but lost during mesoderm formation in vivo. They are absent or expressed very weakly by the migrated cells in vitro. In addition, only explants of the ectoplacental cone (EPC) and visceral endoderm alone, expressed a carbohydrate epitope (recognised by monoclonal antibody BOO6), characteristic of the EPC and primitive endoderm in utero, but absent from mesoderm. Thus we conclude that the cells which outgrow in this system are indeed mesodermal in phenotype. We have confirmed the work of others in demonstrating the presence of fibronectin (FN) and laminin (LN) in the migratory path of the mesoderm, at the ectoderm-visceral endoderm interface. We also report that the beta 1 integrin subunit of the FN and LN receptor is expressed by mesodermal cells at this interface. Using our in vitro model we have examined the role of the extracellular matrix (ECM) in mesodermal migration. Mesodermal cells migrate further and faster on substrates coated with FN or LN, and this increased migration is abolished by appropriate blocking antibodies. We conclude that the ECM, in particular FN and LN, plays an important role in the migration of primary mesodermal cells during gastrulation in the mouse embryo.

Animals↗
PubMed1994

Changes in alpha (1-2)-fucosyltransferase activity in the murine endometrial epithelium during the estrous cycle, early pregnancy, and after ovariectomy and hormone replacement.

alpha (1-2)-Fucosyltransferase (alpha (1-2)-FT) activity in the uterine luminal epithelium was investigated during the estrous cycle, during early pregnancy, and in ovariectomized mice treated with ovarian steroids. Phenyl-beta-D-galactoside was used as a specific acceptor for alpha (1-2)-FT activity. Enzyme activity fell dramatically throughout the pre- and peri-implantation period (Days 1-6 of pregnancy). Activity on Day 4 of pregnancy represented less than a tenth of the Day 1 level and by Day 6 became undetectable. During the estrous cycle alpha (1-2)-FT showed a peak of activity at estrus, the level being similar to that observed on Day 1 of pregnancy. In proestrus, postestrus, and diestrus, activity was similar and was approximately one fifth of that during estrus. Ovariectomized mice were primed with estrogen and treated with progesterone only, estradiol benzoate only, or progesterone followed by a single injection of progesterone and estradiol. Estrogen alone stimulated alpha (1-2)-FT activity, while progesterone treatment was strongly inhibitory. These results correlate well with the pattern of expression of the fucosylated H-type-1 carbohydrate epitope found on the endometrial epithelium and believed to have a role in implantation. alpha (1-2)-FT is capable of catalyzing the final step in formation of the H-type-1 oligosaccharide, and on the basis of our results it is likely that control of this enzyme is the major factor responsible for modulating H-type-1 expression.

Adenosine Triphosphate↗
PubMed1994

Sialylation of terminal saccharides of glycoconjugates expressed by murine molar tooth germs developing in vitro and in vivo.

During development of the mammalian tooth germ the pattern of terminal saccharides of glycoconjugates changes, with many structures losing lectin reactivity in a consistent pattern. This study investigated whether the epitopes are lost or become masked by terminal sialylation, using a combination of neuraminidase treatment of sections and sialic acid-reactive lectins. The results suggested that most of the terminal galactosamine and fucose sites in the epithelial enamel organ were removed during morphogenesis. Conversely, during condensation of the dental mesenchyme, masked peanut agglutinin (PNA)-reactive galactose epitopes appeared. During differentiation and organisation of the mesenchyme into odontoblasts and a subodontoblastic layer the PNA-reactive sites became masked again. These regions also specifically expressed sialylated glucosamine. However, at the proliferating epithelial cervical loop galactose sites appeared to be masked. This was more pronounced during in vitro development when abnormal expression of PNA-reactive sites was found at the cervical loop. Additionally, fucosylated sites persisted in the enamel organ, further indicating that the expression of terminal saccharides was disrupted during development in the organ culture system. These data suggest that loss of terminal galactose and galactosamine is related to differentiation of the cells. However, whether this loss occurs by removal or sialic acid masking is not dependent either on the origin of the cells or the epitope being lost.

Animals↗
PubMed1994

Expression of N-CAM in fertilized pre- and periimplantation and parthenogenetically activated mouse embryos.

The expression of the cell adhesion molecule of the immunoglobulin family, neural cell adhesion molecule (N-CAM), in the pre- and periimplantation embryo was examined by immunocytochemistry. N-CAM is expressed on unfertilized ovulated oocytes, fertilized preimplantation embryos at all stages of development and parthenogenetically activated eggs and embryos. In fertilized embryos, expression from the 4-cell stage can be partially inhibited by blocking embryonic transcription before 38 h post human chorionic gonadotropin (hCG). Expression of N-CAM was reduced on the trophoblast of day 6 blastocysts in culture, weak on the trophoblast of embryonic outgrowths and disappears from invading trophoblast in utero. An antibody against alpha(2-8) linked polysialic acid, mAb2-2B, reacted with embryos from the 8-cell stage, and staining was similarly reduced on the trophoblast of blastocysts at the time of implantation. These results suggest a role for N-CAM in the interactions of cells of the preimplantation mammalian embryo which requires further investigation.

Amanitins↗
PubMed1993

Carbohydrate antigen expression in murine embryonic stem cells and embryos. I. Lacto and neo-lacto determinants.

A comparative study of lacto- and neo-lacto series carbohydrate antigens between the undifferentiated and differentiated derivatives of the embryonic stem (ES) cell line E14 and expression in the early embryo is reported. Antibodies to neo-lacto and lacto (type 1 and 2) precursor chains and blood group antigens such as H (types 1 and 2) A, B and Lewis (Le-a, Le-b, Le-x, Le-y) were examined. Backbone lacto- and neo-lacto structures were present on undifferentiated cells, as were terminal alpha-gal, SSEA-1, Le-y and low levels of Le-a. On differentiation, Le-x (SSEA-1 determinant) disappeared as has been found for embryonal carcinoma (EC) cells, and other determinants became restricted to cells of particular morphology. These observations will aid determination of the status and phenotypic stability of long-term embryonic stem-cell cultures.

Animals↗
PubMed1993

Carbohydrate antigen expression in murine embryonic stem cells and embryos. II. Sialylated antigens and glycolipid analysis.

A mouse embryonic stem (ES) cell line E14 and early mouse embryos were stained with a panel of 15 monoclonal antibodies recognizing sialylated or potentially sialylated carbohydrate determinants. Sialyl Le-x and sialyl Le-a were detected on the pre-implantation embryo from the 8-cell stage, and sialyl Le-a weakly on undifferentiated ES cells. Changes in cell surface carbohydrates occurred after induction of ES cell differentiation with retinoic acid (RA) and dibutyryl cAMP. Qualitative analysis of the neutral glycolipids of untreated and RA-treated ES cells using high-performance thin-layer chromatography (HPTLC) revealed few differences between the two types of culture. The major gangliosides in both cultures were indicative of an active 'a' ganglioside synthesis pathway. GD3, a precursor of the 'b' synthesis pathway, previously reported to be characteristic of embryonal carcinoma (EC) cells, was absent. RA-induced differentiation caused a shift in the spectrum to more complex gangliosides. Application of fast atom bombardment mass spectrometry (FAB-MS) to permethylated derivatives of individual bands permitted partial characterization of an unusual sialylated glycolipid and a rare ganglioside with the suggested structure of GalNAc-GD1a.

Animals↗
PubMed1992

Effect of slow and ultra-rapid freezing on cell surface antigens of 8-cell mouse embryos.

The distribution of four cell surface antigens (SSEA-1, SSEA-3, SSEA-4, and I) present on mouse preimplantation embryos was examined on 8-cell stage embryos immediately after flushing from the reproductive tract and after slow or ultra-rapid freezing. Frozen-thawed and nonfrozen embryos were also examined after culture in vitro for 5, 24, or 48 h. Immediately after thawing, embryos showed a disruption in the polarity of cell surface antigens SSEA-3, SSEA-4, and I, but no differences were detected in fluorescence intensity or various other staining characteristics. No long-term changes in the distribution of cell surface components were detected. Implantation and embryonic development were similar for frozen and nonfrozen embryos transferred to the uterine horns of pseudopregnant recipients.

Animals↗
PubMed1992

Immunofluorescent lectin binding patterns and glycoprotein co-localization in the developing murine molar tooth.

Fluorescein-conjugated lectins were used in conjunction with antibodies to laminin, tenascin and amelogenin to investigate saccharide expression in the developing tooth germ. At the bud stage, peanut agglutinin (PNA) binding demonstrated residues that may be D-galactose-(beta 1----3)DGalNAc, and this staining occurred after the expression of tenascin. Only the cap-stage enamel organ suprabasal cells and the enamel knot stained intensely with Ulex europeus agglutinin-I, but not Lotus tetragonolobus agglutinin, implying the transient presence of blood group H type I oligosaccharides. At the late stages of amelogenesis, enamel synthesis is preceded by en bloc loss of inner enamel basement membrane components. Before this, Bandeiraea (Griffonia) simplicifolia--I (BSL-I) staining was lost from postmitotic ameloblasts, suggesting that a glycosylated species is initially removed. Additionally, PNA was co-localized with amelogenin protein, suggesting that it may express beta-D-galactosyl sequences. These results indicate that the glycosylation patterns of matrix components during odontogenesis may be important as they vary in a manner similar to that of the well-known glycoproteins.

Acetylgalactosamine↗
PubMed1990

Monoclonal antibody 43-9F as a sensitive immunohistochemical marker of carcinoma in situ of human testis.

Invasive germ cell cancer can be prevented if the neoplasia is diagnosed at the stage of carcinoma in situ (CIS). In routine histologic examination CIS may be overlooked, particularly in prepubertal individuals. The detection of this early malignancy may be greatly facilitated by use of immunohistochemical staining. The authors investigated the sensitivity of an immunohistochemical staining procedure with monoclonal antibody 43-9F in detection of CIS. Testicular specimens from 19 adult and two prepubertal individuals with CIS were tested. Positive staining reaction on the surface of malignant germ cells was encountered in all 21 specimens with CIS. The epithelial cells of the excretory ducts between testis and epididymis, including rete testis and canaliculi efferentes, reacted also positively with 43-9F. No staining was observed in nonmalignant testicular cells including Sertoli cells or Leydig cells in any of these samples or in testicular biopsy specimens from 27 adult and 11 prepubertal subjects without evidence of testicular neoplasia. Monoclonal antibody 43-9F was also found to react with cells of all four tested invasive testicular germ cell tumors. Thus, the monoclonal antibody 43-9F is a sensitive immunohistochemical marker of CIS germ cells and may also be of potential value in detection of invasive testicular cancer.

Adult↗
PubMed1990

Hormonal control of a carbohydrate epitope involved in implantation in mice.

Ovariectomy and hormone replacement of mice were used to examine the hormonal control of expression on the uterine surface of a carbohydrate determinant (lacto-N-fucopentaose I, LNF I), involved in the initial interaction between the blastocyst and the endometrial epithelium at implantation. Pseudopregnant mice mated with sterile males were also used to elucidate the impact of embryonic signals on the expression of this antigen on the uterine surface. Two groups of fucosylated structures could be distinguished; one group was predominantly dependent on maternal oestrogen and progesterone, while the other group appeared to be less influenced by the hormonal milieu.

Animals↗