Negative regulatory domains in a trophoblast interferon promoter

ABSTRACT A bovine trophoblast interferon (IFN-τ) gene promoter sequence (− 450 to +26 bp relative to the transcription start site) led to expression of reporter gene (CAT) constructs transfected into L929 (murine fibroblast) or JAR (human choriocarcinoma) cells. Expression depended on the presence of an exogenous (SV40) enhancer. Poly(I)(C) activated endogenous IFN production in L929 and JAR cells but had no consistent effect on CAT expression. Similar results were obtained in L929 cells with inactivated Newcastle disease virus. There was no 'priming' effect of exogenous Type I IFN. Deletion mutants revealed sites exerting negative control on expression between −338 and −247 bp, and between −150 and −71 bp; these regions contained sequences resembling previously identified negative regulatory domains. In the absence of viral inducibility it is proposed that negative regulation contributes towards the stringent control of expression characteristic of IFN-τ genes.

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Silencing of the Gene for the α-Subunit of Human Chorionic Gonadotropin by the Embryonic Transcription Factor Oct-3/4

Molecular Endocrinology ◽

10.1210/mend.11.11.9971 ◽

1997 ◽

Vol 11 (11) ◽

pp. 1651-1658 ◽

Cited By ~ 1

Author(s):

Limin Liu ◽

Douglas Leaman ◽

Michel Villalta ◽

R. Michael Roberts

Keyword(s):

Transcription Factor ◽

Binding Site ◽

Gene Promoter ◽

Site Directed Mutagenesis ◽

Mobility Shift ◽

Α Subunit ◽

Choriocarcinoma Cells ◽

Human Choriocarcinoma Cells ◽

Electrophoretic Mobility Shift Assays ◽

Jar Cells

Abstract CG is required for maintenance of the corpus luteum during pregnancy in higher primates. As CG is a heterodimeric molecule, some form of coordinated control must be maintained over the transcription of its two subunit genes. We recently found that expression of human CG β-subunit (hCGβ) in JAr human choriocarcinoma cells was almost completely silenced by the embryonic transcription factor Oct-3/4, which bound to a unique ACAATAATCA octameric sequence in the hCGβ gene promoter. Here we report that Oct-3/4 is also a potent inhibitor of hCG α-subunit (hCGα) expression in JAr cells. Oct-3/4 reduced human GH reporter expression from the −170 hCGα promoter in either the presence or absence of cAMP by about 70% in transient cotransfection assays, but had no effect on expression from either the −148 hCGα or the −99 hCGα promoter. Unexpectedly, no Oct-3/4-binding site was identified within the −170 to −148 region of the hCGα promoter, although one was found around position −115 by both methylation interference footprinting and electrophoretic mobility shift assays. Site-directed mutagenesis of this binding site destroyed the affinity of the promoter for Oct-3/4, but did not affect repression of the promoter. Therefore, inhibition of hCGα gene transcription by Oct-3/4 appears not to involve direct binding of this factor to the site responsible for silencing. When stably transfected into JAr cells, Oct-3/4 reduced the amounts of both endogenous hCGα mRNA and protein by 70–80%. Oct-3/4 is therefore capable of silencing both hCGα and hCGβ gene expression. We suggest that as the trophoblast begins to form, reduction of Oct-3/4 expression permits the coordinated onset of transcription from the hCGα and hCGβ genes.

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Characterization of Functional Type I Insulin-Like Growth Factor Receptors from Human Choriocarcinoma Cells*

Endocrinology ◽

10.1210/endo-122-2-395 ◽

1988 ◽

Vol 122 (2) ◽

pp. 395-401 ◽

Cited By ~ 23

Author(s):

OLLI RITVOS ◽

EEVA-MARJA RUTANEN ◽

FREDRIKA PEKONEN ◽

JYRKI JALKANEN ◽

ANNE-MARIA SUIKKARI ◽

...

Keyword(s):

Growth Factor ◽

Growth Factor Receptors ◽

Type I ◽

Insulin Like Growth Factor ◽

Functional Type ◽

Choriocarcinoma Cells ◽

Human Choriocarcinoma Cells

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Enhanced green fluorescence protein tracks trichosanthin in human choriocarcinoma cells as a feasible and stable reporter

Frontiers in Bioscience ◽

10.2741/1697 ◽

2005 ◽

Vol 10 (1-3) ◽

pp. 2279 ◽

Cited By ~ 4

Author(s):

Ye, Wang

Keyword(s):

Green Fluorescence Protein ◽

Green Fluorescence ◽

Enhanced Green Fluorescence Protein ◽

Fluorescence Protein ◽

Choriocarcinoma Cells ◽

Human Choriocarcinoma Cells

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Arabidopsis thaliana Myb59 Gene Is Involved in the Response to Heterodera schachtii Infestation, and Its Overexpression Disturbs Regular Development of Nematode-Induced Syncytia

International Journal of Molecular Sciences ◽

10.3390/ijms22126450 ◽

2021 ◽

Vol 22 (12) ◽

pp. 6450

Author(s):

Anita Wiśniewska ◽

Kamila Wojszko ◽

Elżbieta Różańska ◽

Klaudia Lenarczyk ◽

Karol Kuczerski ◽

...

Keyword(s):

Cell Metabolism ◽

Gene Promoter ◽

Promoter Sequence ◽

Regulatory Elements ◽

Heterodera Schachtii ◽

Myb Transcription Factor ◽

Parasitic Nematodes ◽

Regulatory Sequences ◽

Gene Encoding ◽

Constitutive Overexpression

Transcription factors are proteins that directly bind to regulatory sequences of genes to modulate and adjust plants’ responses to different stimuli including biotic and abiotic stresses. Sedentary plant parasitic nematodes, such as beet cyst nematode, Heterodera schachtii, have developed molecular tools to reprogram plant cell metabolism via the sophisticated manipulation of genes expression, to allow root invasion and the induction of a sequence of structural and physiological changes in plant tissues, leading to the formation of permanent feeding sites composed of modified plant cells (commonly called a syncytium). Here, we report on the AtMYB59 gene encoding putative MYB transcription factor that is downregulated in syncytia, as confirmed by RT-PCR and a promoter pMyb59::GUS activity assays. The constitutive overexpression of AtMYB59 led to the reduction in A. thaliana susceptibility, as indicated by decreased numbers of developed females, and to the disturbed development of nematode-induced syncytia. In contrast, mutant lines with a silenced expression of AtMYB59 were more susceptible to this parasite. The involvement of ABA in the modulation of AtMYB59 gene transcription appears feasible by several ABA-responsive cis regulatory elements, which were identified in silico in the gene promoter sequence, and experimental assays showed the induction of AtMYB59 transcription after ABA treatment. Based on these results, we suggest that AtMYB59 plays an important role in the successful parasitism of H. schachtii on A. thaliana roots.

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Effects of chitosan-collagen dressing on wound healing in vitro and in vivo assays

Journal of Applied Biomaterials & Functional Materials ◽

10.1177/2280800021989698 ◽

2021 ◽

Vol 19 ◽

pp. 228080002198969

Author(s):

Min-Xia Zhang ◽

Wan-Yi Zhao ◽

Qing-Qing Fang ◽

Xiao-Feng Wang ◽

Chun-Ye Chen ◽

...

Keyword(s):

Wound Healing ◽

Wound Dressing ◽

Type I Collagen ◽

Inhibition Zone ◽

Negative Control ◽

Type I ◽

Nih3t3 Cells ◽

Post Operation

The present study was designed to fabricate a new chitosan-collagen sponge (CCS) for potential wound dressing applications. CCS was fabricated by a 3.0% chitosan mixture with a 1.0% type I collagen (7:3(w/w)) through freeze-drying. Then the dressing was prepared to evaluate its properties through a series of tests. The new-made dressing demonstrated its safety toward NIH3T3 cells. Furthermore, the CCS showed the significant surround inhibition zone than empty controls inoculated by E. coli and S. aureus. Moreover, the moisture rates of CCS were increased more rapidly than the collagen and blank sponge groups. The results revealed that the CCS had the characteristics of nontoxicity, biocompatibility, good antibacterial activity, and water retention. We used a full-thickness excisional wound healing model to evaluate the in vivo efficacy of the new dressing. The results showed remarkable healing at 14th day post-operation compared with injuries treated with collagen only as a negative control in addition to chitosan only. Our results suggest that the chitosan-collagen wound dressing were identified as a new promising candidate for further wound application.

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