Reporter
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^^^sv. ; 27 cm
Firefly luciferase is susceptible to inhibition and stabilization by compounds under investigation for biological activity and toxicity. This can lead to false-positive results in in vitro cell-based assays. However, firefly luciferase remains one of the most commonly used reporter genes. Here, we evaluated isoflavonoids for inhibition of firefly luciferase. These natural compounds are often studied using luciferase reporter-gene assays. We used a quantitative structure-activity relationship (QSAR) model to compare the results of in silico predictions with a newly developed in vitro assay that enables concomitant detection of inhibition of firefly and Renilla luciferases. The QSAR model predicted a moderate to high likelihood of firefly luciferase inhibition for all of the 11 isoflavonoids investigated, and the in vitro assays confirmed this for seven of them: daidzein, genistein, glycitein, prunetin, biochanin A, calycosin, and formononetin. In contrast, none of the 11 isoflavonoids inhibited Renilla luciferase. Molecular docking calculations indicated that isoflavonoids interact favorably with the D-luciferin binding pocket of firefly luciferase. These data demonstrate the importance of reporter-enzyme inhibition when studying the effects of such compounds and suggest that this in vitro assay can be used to exclude false-positives due to firefly or Renilla luciferase inhibition, and to thus define the most appropriate reporter gene.
- MeSH
- isoflavony chemie metabolismus MeSH
- luciferasy renil chemie metabolismus MeSH
- reportérové geny genetika fyziologie MeSH
- sekundární struktura proteinů MeSH
- světluškovití MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
7 svazků ; 31 cm
Variety of xenobiotics, including therapeutically used vitamin D analogues or environmental and alimentary endocrine disruptors, may interfere with vitamin D receptor (VDR) signaling, with serious physiological or pathophysiological consequences. Therefore, it is of topical interest to have reliable and efficient in vitro screening tools for the identification of agonists and activators of human VDR. We present here two novel stably transfected human reporter cell lines allowing rapid, high-throughput, and selective identification of VDR agonists and activators. Human colon adenocarcinoma cells LS180 were stably transfected with reporter plasmids CYP24_minP-pNL2.1[Nluc/Hygro] (IZ-CYP24 cells contain the -326/-46 sequence from the human CYP24A1 promoter) or VDREI3_SV40-pNL2.1[Nluc/Hygro] (IZ-VDRE cells contain three copies of vitamin D response elements VDRE-I from the human CYP24A1 promoter). Both cell lines remained fully functional for over two months in the culture and also after cryopreservation. Luciferase inductions ranged from 10-fold to 25-fold (RLU 10(6)-10(7)) and from 30-fold to 80-fold (RLU 10(3)-10(4)) in IZ-VDRE and IZ-CYP24 cells, respectively. Time-course analyses revealed that detection of VDR activators is possible as soon as after 8 h of incubation. Cell lines were highly selective toward VDR agonists, displaying no cross-activation by retinoids, thyroids, and steroids. As a proof of concept, we used IZ-VDRE and IZ-CYP24 cells for profiling analogues of vitamin D, and intermediates in vitamin D2 and vitamin D3 metabolic pathways against VDR transcriptional activity. The data obtained revealed significant activation of VDR not only by obligatory ligands calcitriol and ergocalcitriol but also by their precursors and degradation products.
- MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- receptory kalcitriolu metabolismus MeSH
- reportérové geny * MeSH
- rodina 24 cytochromů P450 genetika MeSH
- vitamin D metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Sledovat ovlivnění či průběh genové exprese je v mnoha studiích velmi důležitou součástí výzkumu. V současné době dochází k rozvoji mnoha metod usnadňujících sledování regulace genové exprese, jedním z takových příkladů je využití tzv. genových reportérových testů (z angl. gene reporter assays). Tyto systémy představují rozsáhlý soubor nástrojů ke studiu regulačních sekvencí promotorů, zesilovačů a transkripčních faktorů. Existuje celá řada testů využívajících reportérové buňky pro stanovení biologické aktivity studovaných sloučenin. Cílem tohoto přehledového článku je představit přípravu reportérových plasmidů, což je vždy prvním krokem u testů využívajících reportérové geny. Následně budou popsány nejčastější druhy reportérových testů a představeny příklady jejich použití v testování in vitro.
Monitoring the influence or process of gene expression is a very important part of research in many studies. Currently, many methods are being developed to facilitate the monitoring of gene expression regulation, the use of gene reporter assays being one of the examples. These systems represent an extensive set of tools to study the regulatory sequences of promoters, enhancers, and transcription factors. There are several assays using reporter cells to determine the biological activity of the compounds studied. The aim of this review article is to present the preparation of reporter plasmids, which is always the first step in assays using reporter genes. Subsequently, the most common types of reporter test are described, and examples of their use in in vitro testing are presented.
We developed and characterized the human luciferase reporter cell line PZ-TR for the assessment of thyroid receptor (TR) transcriptional activity. Triiodothyronine (T3) induced luciferase activity in a dose-dependent manner, and the sensitivity of assay allowed for the detection of nanomolar T3 concentrations. The luciferase activity was induced by a maximum of (2.42 ± 0.14)-(2.73 ± 0.23)-fold after 24 h of exposure to 10 nM T3. We did not observe a nonspecific induction of luciferase activity by other steroid hormones and VDR ligands, with the exception of partial activation by retinoic acids. Cryopreservation of PZ-TR cells did not influence their functionality, responsivity to T3, or cell morphology, even after long-term cultivation. PZ-TR cells were used to evaluate the effects of organic tin compounds on TR. We found that the tributyltin and triphenyltin derivatives induced luciferase activity and that application of organotins in combination with T3 enhanced the effect of T3. These findings indicate that organic tin compounds have potential to interfere with TR-mediated regulation of gene expression and influence the physiological activity of thyroid hormones.
- MeSH
- aktivace transkripce účinky léků MeSH
- buněčné linie účinky léků metabolismus MeSH
- endokrinní disruptory farmakologie MeSH
- lidé MeSH
- promotorové oblasti (genetika) účinky léků MeSH
- receptory thyreoidních hormonů genetika metabolismus MeSH
- reportérové geny účinky léků MeSH
- transfekce MeSH
- trijodthyronin metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Glucocorticoids are widely used drugs in human pharmacotherapy. There is an increasing demand for tools allowing detection of the ligands for glucocorticoid receptor (GR), with regard to pre-clinical drug testing and environmental applications. We constructed human luciferase reporter gene cell line AZ-GR derived from HeLa human cervix carcinoma cells, which were stably transfected with reporter plasmid containing three copies of glucorticoid response element (GRE) upstream of luciferase reporter gene. We isolated five dexamethasone-responsive clones, and we further characterized two most responsive ones (AZ-GR). Dose-response analyses were performed with 22 different natural and synthetic steroids and the values of EC(50) were calculated. AZ-GR cells displayed high specificity and sensitivity to glucocorticoids, very low responsiveness to mineralocorticoids, but no responsiveness to estrogens, gestagens or androgens. Time-course analyses revealed that AZ-GR cells allow detection of GR activators soon after 14 h of the treatment (6-10-fold induction by 100 nM dexamethasone). Functionality of AZ-GR cells was not affected with cryopreservation. Generated reporter gene cell lines fully maintained responsiveness to glucocorticoids for 32 days in the culture and over 16 passages without significant alterations. The sensitivity of the assay allows high throughput format using 96-well plates. Collectively, we present here glucocorticoid-responsive stable reporter gene cell line that allows high throughput, rapid, sensitive and selective detection of GR activators, with possible use in pre-clinical research and environmental applications.
- MeSH
- glukokortikoidy farmakologie MeSH
- HeLa buňky MeSH
- lidé MeSH
- luciferasy genetika MeSH
- receptory glukokortikoidů metabolismus MeSH
- reportérové geny genetika MeSH
- rychlé screeningové testy * MeSH
- steroidy farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Identification of chemicals with endocrine-disrupting activities in the past two decades has led to the need for sensitive assays for detection and monitoring of these activities in the environment. In vitro reporter gene assays represent a relatively fast and easy-to-perform method for detection of compounds that are able to bind to hormonal receptors and stimulate or silence their transactivation activity, thus interfering with the hormone signaling pathways. This paper reviews upgrades on reporter gene assays performed during the last decade. The utilization of new reporter genes (luciferase and green fluorescent protein coding genes) significantly improved the sensitivity of the tests and made them faster. Reporter gene assays now represent a high-throughput system for screening chemicals for hormonal activity. Finally, modification of test set-ups for testing anti-hormonal activities also enabled measurements of endocrine-disrupting activities in complex environmental samples such as sediments and wastewater treatment plant effluents.
- MeSH
- antagonisté hormonů toxicita MeSH
- biotest metody MeSH
- chemické látky znečišťující vodu metabolismus MeSH
- endokrinní disruptory MeSH
- luciferasy metabolismus MeSH
- monitorování životního prostředí MeSH
- receptory léků antagonisté a inhibitory MeSH
- reportérové geny MeSH
- Saccharomyces cerevisiae genetika MeSH
- zelené fluorescenční proteiny metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
