Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recently we reported that CD9 is involved in the invasion of a trophoblast-like choriocarcinoma cell line, BeWo, probably through the regulation of integrin functions. Integrins have also been reported to be expressed in the human endometrium and it has been suggested that they play important roles in blastocyst implantation. This study used immunohistochemistry to investigate the expression of CD9 in the endometrium during the menstrual cycle. CD9 was found to be intensely expressed on the cell surface of the glandular epithelium throughout the menstrual cycle without any apparent differences in staining intensity. In addition, Western blotting analysis of the affinity-purified proteins confirmed that CD9 was associated with integrins beta(1), alpha(3) and alpha(6) in the human endometrium. Therefore it can be concluded that CD9, in association with integrins alpha(6), alpha(3) and beta(1), is a constitutive molecule of the endometrial glandular epithelium. These results also suggest that CD9 may be an important regulator of these integrins in the human endometrium.
Mol Hum Reprod 2000 Mar
PMID:CD9 is expressed on human endometrial epithelial cells in association with integrins alpha(6), alpha(3) and beta(1). 1069 73

The human placenta lacks the enzyme 17alpha-hydroxylase/17-20-lyase, and is thus unable to convert cholesterol into estrogens. Therefore estrogen synthesis of trophoblast cells depends on the supply of precursors such as dehydroepiandrosterone-3-sulfate (DHEA-S) and 16alpha-hydroxy-dehydroepiandrosterone-3-sulfate by maternal and fetal blood. To investigate the cellular internalisation of these anionic hydrophilic precursors, the uptake of [(3)H]-/[(35)S]-DHEA-S and [(3)H]-taurocholate by isolated cytotrophoblasts, cells of choriocarcinoma cell lines (JEG-3, BeWo, Jar), BHK and BHK cells transfected with human sterylsulfatase-cDNA (BHK-STS cells) was studied. Furthermore, the activity of sterylsulfatase of these cells in suspension and in corresponding cell homogenate was measured. During the first 5 min of incubation with [(3)H]-DHEA-S or [(35)S]-DHEA-S, radioactivity of cytotrophoblasts increased significantly, while radioactivity of JEG-3, Jar, BHK and BHK-STS cells did not increase. Radioactivity of BeWo cells increased slightly. For all cell types, there was no significant difference for uptake of either substrate. During incubation with [(3)H]-taurocholate, radioactivity of cytotrophoblasts did not increase. Sterylsulfatase activity of cytotrophoblast homogenate was significantly lower than that of cytotrophoblast suspension. Sterylsulfatase activity of BHK-STS, JEG-3 or BeWo cell homogenate was significantly higher than that of the corresponding cell suspension. In BHK and Jar cells sterylsulfatase activity was not detectable. Cytotrophoblasts take up DHEA-S without prior hydrolysis. BHK, BHK-STS, JEG-3, and Jar cells do not take up and BeWo cells slowly take up DHEA-S. In cytotrophoblasts extracellular DHEA-S rapidly gains access to intracellular sterylsulfatase, while in choriocarcinoma and BHK-STS cells access of DHEA-S to sterylsulfatase is limited. Our results indicate, that uptake by cytotrophoblasts is mediated by a carrier which is not expressed in choriocarcinoma or BHK cells and which is different from the known taurocholate-transporting organic anion transporting polypetides.
J Steroid Biochem Mol Biol 1999 Dec 31
PMID:Uptake of dehydroepiandrosterone-3-sulfate by isolated trophoblasts from human term placenta, JEG-3, BeWo, Jar, BHK cells, and BHK cells transfected with human sterylsulfatase-cDNA. 1070 9

DNase I footprint analysis of the human placental lactogen-A (hPL-A) promoter using nuclear extracts from purified human trophoblast cells and BeWo choriocarcinoma cells revealed five protected regions within the proximal 325 bp. Two of the protected regions, FP4 (-289--267) and FP5 (-167--154), are homologous to regions on the human growth hormone (hGH) promoter that bind transcription factors AP-2 and/or NFI. Competitive gel shift assays and supershift assays indicated that FP4 forms complexes with activator protein-2 (AP-2) and nuclear factor I (NFI), while FP5 forms a complex with AP-2 alone. In transient transfection studies in human trophoblast cells, hPL promoter constructs containing point mutations in the AP-2 binding sites of FP4 and/or FP5 were 60-80% less active than plasmids containing the wild-type promoter. A mutation in the NFI binding site of FP4, however, had little effect on promoter activity in these cells. Overexpression of AP-2 in HepG2 cells co-transfected with the wild-type hPL promoter resulted in a significant increase in promoter activity. Taken together, these findings suggest a critical role for AP-2 in the regulation of hPL gene expression.
Mol Cell Endocrinol 2000 Feb 25
PMID:Activator protein-2 regulates human placental lactogen gene expression. 1071 52

The aim of these studies was to elucidate a role for epidermal growth factor (EGF) signaling in the transcriptional regulation of the glycoprotein hormone alpha subunit gene, a subunit of chorionic gonadotropin. Studies examined the effects of EGF and the adenylate cyclase activator forskolin on the expression of a transfected alpha subunit reporter gene in a human choriocarcinoma cell line (JEG3). At maximal doses, administration of EGF resulted in a 50% increase in a subunit reporter activity; forskolin administration induced a fivefold activation; the combined actions of EGF and forskolin resulted in synergistic activation (greater than eightfold) of the alpha subunit reporter. Mutagenesis studies revealed that the cyclic AMP response elements (CRE) were required and sufficient to mediate EGF-forskolin-induced synergistic activation. The combined actions of EGF and forskolin resulted in potentiated activation of extracellular signal-regulated kinase (ERK) enzyme activity compared with EGF alone. Specific blockade of ERK activation was sufficient to block EGF-forskolin-induced synergistic activation of the alpha subunit reporter. Pretreatment of JEG3 cells with a p38 mitogen-activated protein kinase inhibitor did not influence activation of the alpha reporter. However, overexpression of c-Jun N-terminal kinase (JNK)-interacting protein 1 as a dominant interfering molecule abolished the synergistic effects of EGF and forskolin on the alpha subunit reporter. CRE binding studies suggested that the CRE complex consisted of CRE binding protein and EGF-ERK-dependent recruitment of c-Jun-c-Fos (AP-1) to the CRE. A dominant negative form of c-Fos (A-Fos) that specifically disrupts c-Jun-c-Fos DNA binding inhibited synergistic activation of the alpha subunit. Thus, synergistic activation of the alpha subunit gene induced by EGF-forskolin requires the ERK and JNK cascades and the recruitment of AP-1 to the CRE binding complex.
Mol Cell Biol 2000 May
PMID:Role of the cyclic AMP response element binding complex and activation of mitogen-activated protein kinases in synergistic activation of the glycoprotein hormone alpha subunit gene by epidermal growth factor and forskolin. 1077 23

At the initial phase of embryo implantation, the trophoblast must have acquired competence for adhesion to the uterine epithelium, a condition whose cell biological basis is far from understood. In the present study, trophoblast-type cells (BeWo, JAr, and Jeg-3 choriocarcinoma cell lines) were treated with retinoic acid, methotrexate, dibutyryl-cAMP, or phorbol-12-myristate-13-acetate in order to modulate their ability to adhere to uterine epithelial cells (RL95-2). In an established model, multicellular spheroids of choriocarcinoma cells were transferred onto the surface of monolayer cultures of RL95-2 cells followed by a centrifugal force-based adhesion assay. In controls, about 45% of BeWo and JAr cell spheroids and 75% of Jeg-3 spheroids adhered to uterine monolayers within 30 min. Pretreatment of spheroids with either of the agents stimulated differentiation as indicated by the rate of chorionic gonadotropin secretion, but consistently reduced the adhesion to the endometrial monolayer in all three choriocarcinoma cell lines. While previous investigations had shown that invasiveness of trophoblast cells (into extracellular matrix) does not seem to be linked to the differentiation program in a simple manner, the present data suggest that such an (inverse) link may indeed exist with respect to the ability to initiate an adhesive interaction with the uterine epithelium. These observations support the view that epithelial cell interactions as typical for the initial phase of embryo implantation are regulated in a way that is clearly different from cell-matrix interactions governing later phases of trophoblast invasion into the endometrial stroma.
Mol Reprod Dev 2000 Oct
PMID:Adhesion of trophoblast to uterine epithelium as related to the state of trophoblast differentiation: in vitro studies using cell lines. 1098 13

The glycoprotein hormone alpha-subunit (GPHalpha) gene is inducible by sodium butyrate (NaBtr) in nontrophoblastic tumor cell lines such as HeLa (cervical carcinoma) but not in trophoblastic tumor cell lines such as JEG-3 (choriocarcinoma). The studies summarized in this report examined the ability of NaBtr to induce GPHalpha expression in somatic cell hybrids between HeLa SR3(hyg) and JEG-3(neo). The hybrid cells, pooled clones resistant to both hygromycin B and G418 sulfate, have been named JELA and were indistinguishable from the SR3 parent with regard to induction of the GPHalpha gene. The effects of NaBtr on cell proliferation were also similar in HeLa and JELA but different from those in JEG-3. The GPHalpha gene could be induced by NaBtr in the JEG-3 parent only when they were simultaneously treated with cycloheximide (CHX). The ability of NaBtr to induce GPHalpha in CHX-treated JEG-3 cells occurred concomitantly with a change in the electrophoretic mobility of enhancer binding proteins as determined in gel shift assays. The DNA-protein complexes generated between a trophoblast specific element (TSE) and nuclear proteins in HeLa SR3 and JELA migrated significantly more slowly than the complex generated by JEG-3 nuclear proteins. However, when nuclear extracts were prepared from CHX-treated JEG-3 cells, the complex generated with the TSE oligonucleotide migrated more slowly than the complex from untreated JEG-3 cells and coincident with the complexes produced with nuclear extracts from HeLa SR3 and JELA cells. Together, these data demonstrate that inducibility of the GPHalpha gene by NaBtr in JELA cell hybrids resembles that of the HeLa SR3 parent and that its inducibility in the JEG-3 parent parallels the status of an enhancer binding protein (TSEB) as judged from changes in electrophoretic mobility. The results are consistent with a model in which the status of TSEB has a profound influence on the gene's response to NaBtr.
Mol Cell Biol Res Commun 2000 Jun
PMID:Cellular responses to sodium butyrate exhibit the dominance of one parental phenotype in somatic cell hybrids. 1103 54

The human placenta has a remarkable capacity to aromatize C19-steroids, produced by the fetal adrenals, to estrogens. This reaction is catalyzed by aromatase P450 (P450arom), encoded by the CYP19 gene. In placenta, CYP19 gene expression is restricted to the syncytiotrophoblast layer. Cytotrophoblasts isolated from human placenta, when placed in monolayer culture in 20% O2, spontaneously fuse to form syncytiotrophoblast. These morphological changes are associated with a marked induction of aromatase activity and CYP19 gene expression. When cytotrophoblasts are cultured in an atmosphere containing 2% O2, they manifest increased rates of DNA synthesis and fail to fuse and form syncytiotrophoblast. The objective of the present study was to utilize cytotrophoblasts isolated from midterm human placenta to analyze the effects of O2 on CYP19 gene expression and the molecular mechanisms that mediate these effects. We observed that when trophoblast cells were maintained in 2% O2, there was only a modest induction of CYP19 expression as a function of time in culture, and aromatase activity was barely detectable. However, when cytotrophoblasts that had been maintained in 2% O2 for 3 days were placed in a 20% O2 environment, there was a rapid onset of cell fusion and induction of P450arom mRNA and aromatase activity. In addition, mRNAs for the helix-loop-helix factors Mash-2 (mammalian achaete-scute homologous protein-2) and Id1 (inhibitor of differentiation 1) were readily detectable in freshly isolated cytotrophoblasts and were markedly decreased upon differentiation to syncytiotrophoblast in 20% O2. By contrast, when cytotrophoblasts were cultured in 2% O2, mRNA levels for Mash-2 and Id1 remained elevated. Interestingly, overexpression of Mash-2 in primary cultures of human trophoblast cells markedly inhibited cell fusion and the spontaneous induction of P450arom mRNA levels and caused a marked decrease in expression of co-transfected fusion gene constructs containing either 125, 201, 246, or 501 bp of DNA flanking the 5'-end of the placenta-specific exon (exon I.1) of the human CYP19 gene linked to the human GH (hGH) structural gene, as reporter. In studies using BeWo, a human choriocarcinoma cell line, overexpression of Mash-2 also inhibited expression of cotransfected CYP19I.1:hGH fusion gene constructs. The findings that Mash-2 had no effect on the expression of a CYP19I.1(-42):hGH fusion gene in primary cultures of human trophoblast and BeWo cells suggest that Mash-2 exerts its inhibitory effects directly or indirectly though CYP19I.1 5'-flanking sequences that lie between -42 and -125 bp. By contrast, neither Id1 nor Id2 had an effect on CYP19I. 1 promoter activity in the transfected BeWo cells. These findings suggest that Mash-2 may serve as a hypoxia-induced transcription factor that prevents differentiation to syncytiotrophoblast and aromatase induction in human trophoblast cultured under low O2 conditions.
Mol Endocrinol 2000 Oct
PMID:Hypoxia prevents induction of aromatase expression in human trophoblast cells in culture: potential inhibitory role of the hypoxia-inducible transcription factor Mash-2 (mammalian achaete-scute homologous protein-2). 1104 80

Human UDP-d-xylose:proteoglycan core protein beta-d-xylosyltransferase (EC 2.4.2.26, XT-I) initiates the biosynthesis of glycosaminoglycan chains in proteoglycans by transferring xylose from UDP-xylose to specific serine residues of the core protein. Based on the partial amino acid sequence of the purified enzyme from human JAR choriocarcinoma cell culture supernatant we isolated a cDNA encoding XT-I using the degenerate reverse transcriptase-polymerase chain reaction method. This enzyme, which is involved in chondroitin sulfate, heparan sulfate, heparin and dermatan sulfate biosynthesis, belongs to a novel family of glycosyltransferases with no homology to proteins known so far. 5' and 3'-RACE were performed to isolate a novel cDNA fragment of 3726 bp with a single open reading frame encoding at least 827 amino acid residues with a molecular mass of 91 kDa. The human XT-I gene was located on chromosome 16p13.1 using radiation hybrid mapping, and extracts from CHO-K1 cells transfected with the XT-I cDNA in an expression vector exhibited marked XT activity. A new 3608 bp cDNA fragment encoding a protein of 865 amino acid residues was also isolated by PCR using degenerate primers based on the amino acid sequence of human XT-I. The amino acid sequence of this XT-II isoform displayed 55% identity to the human XT-I. The XT-II gene was located on chromosome 17q21.3-17q22, and the exon/intron structure of the 15 kb gene was determined. RT-PCR analyses of XT-I and XT-II mRNA from various tissues confirmed that both XT-I and XT-II transcripts are ubiquitously expressed in the human tissues, although with different levels of transcription. Furthermore, the cDNAs encoding XT-I and XT-II from rat were cloned. The deduced amino acid sequences of rat xylosyltransferases displayed 94% identity to the corresponding human enzyme.
J Mol Biol 2000 Dec 08
PMID:Molecular cloning and expression of human UDP-d-Xylose:proteoglycan core protein beta-d-xylosyltransferase and its first isoform XT-II. 1109 77

Cyp19 encodes aromatase cytochrome P450, the key enzyme of oestrogen biosynthesis. In the bovine placenta, the majority of Cyp19 transcripts include a 5' untranslated region which is encoded by exon 1.1; this suggests that its 5'-flanking region is the predominant placental promoter. The aim of the present investigation was to examine the promoter activity of this region and to map cis-acting regulatory elements in order to improve our understanding of the complex regulation of this gene within the placenta. As an initial approach, human JEG-3 choriocarcinoma cells were transiently transfected with reporter-gene constructs consisting of different 5'-flanking sequences of exon 1.1 fused to the luciferase gene as a reporter. To localise and further characterise functional cis-acting elements, targeted point mutations and electrophoretic mobility-shift experiments were used. The data demonstrate, for the first time, (1) that the bovine exon 1.1 5'-flanking sequence is an active promoter, (2) that 404 bp of this region are sufficient for constitutive reporter-gene expression in JEG-3 cells and (3) that the region includes at least two different enhancer elements; the data also suggest (4) that one of these elements consists of the E-box motif CATGTG and that the second enhancer element includes the half-site hexameric sequence AGGTCA and additional nucleotides flanking this element upstream.
J Mol Endocrinol 2000 Dec
PMID:Cis-acting elements regulating the placenta-specific promoter of the bovine Cyp19 gene. 1111 6

We previously analysed the plasma membrane proteins of rat placenta and prepared a database of 150 plasma membrane proteins, expressed in a stage-specific manner, utilizing two-dimensional gel electrophoresis (2D/E) [Mol. Cell. Endocrinol. 115(1995)149]. In this study, we focused on the proteins, tentatively named psL-I (MW 36.2 kDa, pI 5.3) and psL-II (35.9 kDa, 5.3), which were expressed mainly in late pregnancy. Close to psL-I and psL-II on 2D/E gels, we also recognized more abundant proteins [psC-I (36.2 kDa, 5.4) and psC-II (35.9 kDa, 5.4), respectively] arranged side by side with the same MW but different pI. Expression of psL-I and psL-II was detected only in junctional zone of placenta, whereas psC-I and psC-II were expressed in both labyrinth and junctional zones. In addition, psL-I and psL-II began to increase on day 16 of pregnancy and peaked at term, whereas expression of psC-I and psC-II was relatively constant. The analysis of these four proteins (psL-I, psL-II, psC-I and psC-II) by preparative 2D/E, peptide mapping, amino acid sequence and mass spectrometry (MALDI-TOF-MS) revealed that psC-I was a G protein beta1 subunit, and psC-II was a beta2 subunit, and showed that psL-I and psL-II were molecular modified forms of psC-I and psC-II, respectively. Expression of these G protein beta subunits (psL-I, psL-II, psC-I and psC-II) was also observed in rat choriocarcinoma cells, Rcho-1 cells. Expression of psC-I and psC-II was much higher than those of psL-I and psL-II, and their level was relatively constant regardless of the stage of differentiation in vitro. Interestingly, expression of psL-I and psL-II gradually increased in association with the differentiation. Since the expression of beta1 and beta2 subunit proteins and their mRNAs was constant during the process of differentiation in Rcho-1 cells, the expression of these lower pI forms of G protein subunits (psL-I and psL-II) was thought to be post-translationally regulated. In conclusion, there are modified forms of G protein beta1 and beta2 subunits, in the placenta and Rcho-1 cells, which are expressed in a pregnancy-stage or differentiation stage specific manner.
Mol Cell Endocrinol 2001 Mar 28
PMID:Stage-specific modification of G protein beta subunits in rat placenta. 1130 74


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