• MeSH
• exprese genu MeSH
• genetická transkripce MeSH
• intracelulární tekutina fyziologie   MeSH
• kationty jednomocné MeSH
• kultivované buňky MeSH

Colchicine is an antimitotic drug which binds to tubulin and at high doses results in cytoskeleton disruption. Colchicine is believed to be an anti-inflammatory agent, though its modulatory effects on the level and transcriptional activity of genes is still a matter of debate. There is growing evidence that alterations in the cytoskeleton exert specific effects on the expression of various genes. This study was undertaken to analyze whether disrupting the microtubule cytoskeleton by colchicine modulates transcriptional levels of MEFV, NF-κB p65, NLRP3, HMGB1, and caspase-3 in neutrophils from patients with familial Mediterranean fever (FMF) and healthy subjects. In the present study, colchicine caused increased expression of NLRP3 (p=0.007) and MEFV (p=0.03), but had no effect on caspase-3, NF-κB p65 and HMGB1 genes in healthy neutrophils. FMF neutrophils were less responsive to the drug treatment. This study supports the hypothesis that, being an anti-inflammatory agent, colchicine at relatively high concentrations might lead to the activation of pro-inflammatory signalling pathways in neutrophils.

• MeSH
• cytoskeletální proteiny genetika   MeSH
• dospělí MeSH
• familiární středomořská horečka krev   farmakoterapie   genetika   MeSH
• kaspasa 3 genetika   MeSH
• kolchicin farmakologie   MeSH
• kultivované buňky MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• neutrofily účinky léků   fyziologie   MeSH
• protein HMGB1 genetika   MeSH
• regulace genové exprese účinky léků   MeSH
• studie případů a kontrol MeSH
• transkripční faktor RelA genetika   MeSH
• transportní proteiny genetika   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• embryologie a teratologie
• mikrobiologie, lékařská mikrobiologie
• genetika, lékařská genetika

Microphthalmia-associated transcription factor (MITF) activates the expression of melanocyte-specific markers and promotes the survival of embryonic, adult and malignant melanocytes. Although numerous MITF-dependent downstream genes have been identified, the mechanisms by which the MITF activity is coregulated remain elusive. Here we used a non-melanocytic cell line U2-OS as a model in which MITF evokes transcription of a paradigmatic MITF target tyrosinase and show that the adenoviral E1A protein represses the MITF-driven transcription in these cells. The E1A CR1 domain (which alone is insufficient to bind p300) was sufficient for repression, while the N-terminus, through which E1A binds the p300/CBP proteins and other coactivators, was unable to repress. Correspondingly, CR1 inhibited colony formation of MITF-positive, but not MITF-negative, melanoma cells. The repression by CR1 was largely independent of the PCAF-binding motif, previously recognized to be necessary for suppression of muscle-specific enhancer. Interestingly, CR1 conferred transcriptional competence to the MITF-CR1 chimera in which the MITF portion was rendered transcription-deficient. Moreover, MITF mutants defective in binding to p300/CBP in vivo still activated transcription, further supporting a p300/CBP-independent coactivation of MITF targets. MITF is amplified in a subset of melanomas and is thought to be required for sustained proliferation of malignant melanocytes. Our results suggest that understanding how CR1 represses Mitf activity may reveal a route to melanoma therapy.

• MeSH
• adenovirové proteiny E1A chemie   MeSH
• aktivace enzymů MeSH
• aktivace transkripce MeSH
• down regulace MeSH
• financování organizované MeSH
• histonacetyltransferasy metabolismus   MeSH
• lidé MeSH
• melanom enzymologie   genetika   patologie   MeSH
• molekulární sekvence - údaje MeSH
• mutantní proteiny chemie   MeSH
• nádorové buněčné linie MeSH
• regulace genové exprese enzymů MeSH
• regulace genové exprese u nádorů MeSH
• represorové proteiny metabolismus   MeSH
• sekvence aminokyselin MeSH
• terciární struktura proteinů MeSH
• testy nádorových kmenových buněk MeSH
• transkripční faktor spojený s mikroftalmií genetika   MeSH
• transkripční faktory p300-CBP metabolismus   MeSH
• tyrosinasa genetika   metabolismus   MeSH
• vazba proteinů MeSH
• Check Tag
• lidé MeSH

Intracellular protein aggregation causes proteotoxic stress, underlying highly debilitating neurodegenerative disorders in parallel with decreased proteasome activity. Nevertheless, under such stress conditions, the expression of proteasome subunits is upregulated by Nuclear Factor Erythroid 2-related factor 1 (NRF1), a transcription factor that is encoded by NFE2L1. Activating the NRF1 pathway could accordingly delay the onset of neurodegenerative and other disorders with impaired cell proteostasis. Here, we present a series of small-molecule compounds based on bis(phenylmethylen)cycloalkanones and their heterocyclic analogues, identified via targeted library screening, that can induce NRF1-dependent downstream events, such as proteasome synthesis, heat shock response, and autophagy, in both model cell lines and Caenorhabditis elegans strains. These compounds increase proteasome activity and decrease the size and number of protein aggregates without causing any cellular stress or inhibiting the ubiquitin-proteasome system (UPS). Therefore, our compounds represent a new promising therapeutic approach for various protein conformational diseases, including the most debilitating neurodegenerative diseases.

• MeSH
• aktivace transkripce účinky léků   MeSH
• autofagie účinky léků   MeSH
• Caenorhabditis elegans * účinky léků   metabolismus   MeSH
• faktor 1 související s NF-E2 metabolismus   genetika   MeSH
• knihovny malých molekul farmakologie   MeSH
• lidé MeSH
• patologická konformace proteinů metabolismus   farmakoterapie   MeSH
• proteasomový endopeptidasový komplex * metabolismus   MeSH
• proteinové agregáty * účinky léků   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Most human tumors contain inactivated p53 protein, either by mutations and/or functional deactivation. Restoration of wild-type p53 function could be one of the key tools in new anticancer therapy. Using an electromobility shift assay, we investigated the effect of temperature on DNA binding of wild-type and mutant p53 proteins. We showed that analysis of the DNA-binding capacity of mutant p53 proteins is complicated by the temperature at which the assay is performed. Furthermore, neither ability to bind to DNA nor conformational analysis accurately defines the transcriptional activity of human tumor-derived p53 mutant proteins. That some mutants can bind DNA and adopt a wild-type conformation in vitro, but are transcriptionally inactive in vivo, points to the involvement of cellular factors required for transactivation. Therefore, the common use of purified proteins and in vitro determinations of DNA binding and conformation are not the best indicators of the functional properties of mutant p53.

• MeSH
• aktivace transkripce * MeSH
• DNA * metabolismus   MeSH
• konformace proteinů MeSH
• lidé MeSH
• mutace MeSH
• nádorové buněčné linie MeSH
• nádorový supresorový protein p53 fyziologie   genetika   metabolismus   MeSH
• retardační test MeSH
• teplota MeSH
• vazba proteinů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH

The pregnane X receptor (PXR, encoded by the NR1I2 gene) is a ligand-regulated transcription factor originally described as a master regulator of xenobiotic detoxification. Later, however, PXR was also shown to interact with endogenous metabolism and to be further associated with various pathological states. This review focuses predominantly on such aspects, currently less covered in literature, as the control of PXR expression per se in the context of inter-individual differences in drug metabolism. There is growing evidence that non-coding RNAs post-transcriptionally regulate PXR. Effects on PXR have especially been reported for microRNAs (miRNAs), which include miR-148a, miR-18a-5p, miR-140-3p, miR-30c-1-3p and miR-877-5p. Likewise, miRNAs control the expression of both transcription factors involved in PXR expression and regulators of PXR function. The impact of NR1I2 genetic polymorphisms on miRNA-mediated PXR regulation is also discussed. As revealed recently, long non-coding RNAs (lncRNAs) appear to interfere with PXR expression. Reciprocally, PXR activation regulates non-coding RNA expression, thus comprising another level of PXR action in addition to the direct transactivation of protein-coding genes. PXR expression is further controlled by several transcription factors (cross-regulation) giving rise to different PXR transcript variants. Controversies remain regarding the suggested role of feedback regulation (auto-regulation) of PXR expression. In this review, we comprehensively summarize the miRNA-mediated, lncRNA-mediated and transcriptional regulation of PXR expression, and we propose that deciphering the precise mechanisms of PXR expression may bridge our knowledge gap in inter-individual differences in drug metabolism and toxicity.

• MeSH
• biologická variabilita populace * MeSH
• biotransformace MeSH
• farmakogenetika MeSH
• farmakogenomické varianty * MeSH
• fenotyp MeSH
• genetická transkripce * MeSH
• genotyp MeSH
• lidé MeSH
• mikro RNA genetika   metabolismus   MeSH
• posttranskripční úpravy RNA * MeSH
• pregnanový X receptor genetika   metabolismus   MeSH
• RNA dlouhá nekódující genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

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

Pregnane X receptor (PXR) is a major transcriptional regulator of xenobiotic metabolism and transport pathways in the liver and intestines, which are critical for protecting organisms against potentially harmful xenobiotic and endobiotic compounds. Inadvertent activation of drug metabolism pathways through PXR is known to contribute to drug resistance, adverse drug-drug interactions, and drug toxicity in humans. In both humans and rodents, PXR has been implicated in non-alcoholic fatty liver disease, diabetes, obesity, inflammatory bowel disease, and cancer. Because of PXR's important functions, it has been a therapeutic target of interest for a long time. More recent mechanistic studies have shown that PXR is modulated by multiple PTMs. Herein we provide the first investigation of the role of acetylation in modulating PXR activity. Through LC-MS/MS analysis, we identified lysine 109 (K109) in the hinge as PXR's major acetylation site. Using various biochemical and cell-based assays, we show that PXR's acetylation status and transcriptional activity are modulated by E1A binding protein (p300) and sirtuin 1 (SIRT1). Based on analysis of acetylation site mutants, we found that acetylation at K109 represses PXR transcriptional activity. The mechanism involves loss of RXRα dimerization and reduced binding to cognate DNA response elements. This mechanism may represent a promising therapeutic target using modulators of PXR acetylation levels. This article is part of a Special Issue entitled: Xenobiotic nuclear receptors: New Tricks for An Old Dog, edited by Dr. Wen Xie.

• MeSH
• acetylace MeSH
• aktivace transkripce * MeSH
• buňky Hep G2 MeSH
• DNA chemie   metabolismus   MeSH
• Escherichia coli genetika   metabolismus   MeSH
• HEK293 buňky MeSH
• HeLa buňky MeSH
• klonování DNA MeSH
• lidé MeSH
• luciferasy genetika   metabolismus   MeSH
• lysin chemie   metabolismus   MeSH
• molekulární modely MeSH
• multimerizace proteinu MeSH
• mutageneze cílená MeSH
• posttranslační úpravy proteinů * MeSH
• rekombinantní proteiny chemie   genetika   metabolismus   MeSH
• reportérové geny MeSH
• responzivní elementy MeSH
• sekundární struktura proteinů MeSH
• sirtuin 1 genetika   metabolismus   MeSH
• steroidní receptory chemie   genetika   metabolismus   MeSH
• strukturní homologie proteinů MeSH
• transkripční faktory p300-CBP genetika   metabolismus   MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

The human glucocorticoid receptor (hGR) plays a pivotal role in cellular processes such as development, differentiation, homeostasis, immune response and in regulation of xenobiotic metabolism. It has been demonstrated recently that colchicine inhibits hGR transcriptional activity in primary cultures of human hepatocytes by a mechanism involving impairment of hGR nucleo-cytoplasmic shuttling. In the present work, we investigated the role of the nuclear factor kappa B (NFkappaB) and c-jun-N-terminal kinase (JNK), the functional hGR antagonists, in this process. We found that microtubule disarray caused by colchicine, vincristine or nocodazole does not activate NFkappaB in human hepatocytes as revealed by p50 and p65 subunits nuclear translocation. On the other hand, we demonstrate that JNK mediates hGR transcriptional inhibition by microtubules disarray, because a specific inhibitor of JNK, 1,9-pyrazoloanthrone (SP600125), partially blocked tyrosine aminotransferase mRNA suppression due to colchicine treatment. In conclusion, JNK is at least partly involved in hGR transcriptional inhibition by colchicine in human hepatocytes, while NFkappaB involvement is doubtful.

• MeSH
• aktivace enzymů MeSH
• aktivace transkripce účinky léků   MeSH
• anthraceny farmakologie   MeSH
• hepatocyty metabolismus   ultrastruktura   MeSH
• JNK mitogenem aktivované proteinkinasy antagonisté a inhibitory   metabolismus   MeSH
• kolchicin farmakologie   MeSH
• kultivované buňky MeSH
• lidé MeSH
• mikrotubuly účinky léků   ultrastruktura   MeSH
• NF-kappa B metabolismus   farmakologie   MeSH
• receptory glukokortikoidů antagonisté a inhibitory   fyziologie   MeSH
• tyrosinaminotransferasa metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH