scholarly journals Activating Effect of Benzbromarone, a Uricosuric Drug, on Peroxisome Proliferator-Activated Receptors

PPAR Research ◽  
2007 ◽  
Vol 2007 ◽  
pp. 1-5 ◽  
Author(s):  
Chiyoko Kunishima ◽  
Ikuo Inoue ◽  
Toshihiro Oikawa ◽  
Hiromu Nakajima ◽  
Tsugikazu Komoda ◽  
...  
Keyword(s):  
Binding Affinity ◽  
Cultured Cells ◽  
Binding Activity ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferation ◽  
Mobility Shift ◽  
Peroxisome Proliferator Activated Receptor ◽  
Western Blot Method ◽  
Gene Assay ◽  
Mobility Shift Assay

Benzbromarone, a uricosuric drug, reportedly causes hepatic hypertrophy accompanied by proliferation of peroxisomes in rats. To elucidate the mechanisms underlying induction of peroxisome proliferation by benzbromarone, we examined binding affinity for peroxisome proliferator-activated receptorα(PPARα) andγ(PPARγ), and effects on the binding activity of PPARs with peroxisome proliferation-responsive element (PPRE) and expression of the PPARs target protein. Binding affinity of benzbromarone forPPARαandPPARγwas examined by reporter gene assay. Binding activity of PPARs with PPRE was determined by electric mobility shift assay, and expression of lipoprotein lipase (LPL) and acyl-CoA synthetase (ACS) by Western blot method. Benzbromarone displayed affinity forPPARαandPPARγ, and promoted binding of PPARs to PPRE. Furthermore, cultured cells with benzbromarone added showed upregulated expression of LPL and ACS. These results suggest that benzbromarone induces peroxisome proliferation in hepatocytes by binding to PPARs, and controls expression of proteins related to lipid metabolism.

Transcriptional ERRγ2-mediated activation is regulated by sentrin-specific proteases

2009 ◽  
Vol 419 (1) ◽  
pp. 167-176 ◽  
Author(s):  
Moritz Hentschke ◽  
Ute Süsens ◽  
Uwe Borgmeyer
Keyword(s):  
Nuclear Receptor ◽  
Mutational Analysis ◽  
Activation Function ◽  
Peroxisome Proliferator ◽  
Orphan Nuclear Receptor ◽  
Mobility Shift ◽  
Peroxisome Proliferator Activated Receptor ◽  
Specific Protease ◽  
Mobility Shift Assay ◽  
Group B

Modification with SUMOs (small ubiquitin-related modifiers) has emerged as an important means of regulating the activity of transcription factors, often by repressing their activity. The ERRγ [oestrogen receptor-related receptor γ; ERR3 or NR3B3 (nuclear receptor subfamily 3, group B, gene3)] is a constitutively active orphan nuclear receptor. A PDSM, (phosphorylation-dependent sumoylation motif) is located in the close vicinity of the N-terminally located ERRγ2-specific AF-1 (activation function-1). Its function can be replaced by an NDSM (negatively charged amino acid-dependent sumoylation motif). A mutational analysis reveals that ERRγ2 activity is modulated through sumoylation of a lysine residue at position 40, which in turn is regulated by phosphorylation. Phosphorylation at the +5 position relative to the sumoylation target is directly visualized by a high-resolution EMSA (electrophoretic mobility-shift assay). Sumoylation represses the activity of ERRγ both with and without forced expression of the PGC-1β (peroxisome-proliferator-activated receptor γ co-activator-1β). Fusion proteins of a heterologous DNA-binding domain with the ERRγ2 N-terminus demonstrate the function of the PDSM as the RF-1 (repression function-1) for the neighbouring AF-1. De-repression is achieved by co-expression of sentrin/SENP (sentrin-specific protease) family members. Together, our results demonstrate reversible phosphorylation-dependent sumoylation as a means to regulate the activity of an orphan nuclear receptor.

scholarly journals Peroxisome Proliferator-Activated Receptor Gamma Exacerbates Concanavalin A-Induced Liver Injury via Suppressing the Translocation of NF-κB into the Nucleus

PPAR Research ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Yuji Ogawa ◽  
Masato Yoneda ◽  
Wataru Tomeno ◽  
Kento Imajo ◽  
Yoshiyasu Shinohara ◽  
...  
Keyword(s):  
Liver Injury ◽  
Concanavalin A ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Peroxisome Proliferator ◽  
Con A ◽  
Mobility Shift ◽  
Peroxisome Proliferator Activated Receptor ◽  
Knock Out ◽  
In The Wild ◽  
Mobility Shift Assay

Peroxisome proliferator-activated receptor-γ(PPARγ) has been reported to reduce inflammation and attenuate fibrosis in the liver. In this study, we investigated the effects of PPARγon the liver injury induced by 20 mg/kg Concanavalin A (Con A). The mice were administered one of the three types of PPARγligands (pioglitazone, ciglitazone, and troglitazone) for 1 week, and the serum alanine aminotransferase (ALT) levels at 20 h after Con A injection were significantly elevated in the PPARγligand-treated mice. Furthermore, the serum ALT levels after Con A injection in the PPARγhetero-knock-out mice (PPARγ+/−mice) were lower than those in the wild-type mice (WT mice). Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) revealed extensive liver damage induced by Con A in the pioglitazone-treated mice. Electrophoresis mobility shift assay (EMSA) revealed that activation of translocation of nuclear factor- (NF-)κB, which is a suppressor of apoptosis, in the nucleus of the hepatocytes was suppressed in the pioglitazone-treated mice after Con A injection. In this study, we showed that PPARγexacerbated Con A-induced liver injury via suppressing the translocation of NF-κB into the nucleus, thereby inhibiting the suppression of liver cell apoptosis.

scholarly journals Analysis of nuclear glucocorticoid receptor-DNA interaction in aged rat liver

2005 ◽  
Vol 70 (5) ◽  
pp. 705-712 ◽  
Author(s):  
Miroslava Vujcic ◽  
Natasa Terzic ◽  
Aleksandra Ristic-Fira ◽  
Dusan Kanazir ◽  
Sabera Ruzdijic
Keyword(s):  
Dna Interaction ◽  
Binding Activity ◽  
Regulatory Proteins ◽  
Nuclear Proteins ◽  
Middle Aged ◽  
Mobility Shift ◽  
Nuclear Extracts ◽  
Supershift Assay ◽  
Mobility Shift Assay ◽  
Oligonucleotide Analogues

Abstract: In order to contribute to the understanding of mechanisms by which regulatory proteins recognize genetic information stored in DNA, analyses of their interaction with specific nucleotides are usually performed. In this study, the electrophoretic mobility shift assay (EMSA) was applied to analyze the interaction of nuclear proteins from the liver of rats of different age i.e., young (3-month-old), middle- aged (12-month-old) and aged (24-month-old), with radioactively labelled synthetic oligonucleotide analogues, corresponding to GRE. The levels of GRE binding activity were assessed by quantitative densitometric scanning of the autoradiograms. The results showed statistically significant decreasing values of up to 78% and 49% in middle aged and old animals, respectively, compared to young animals (p < 0.05). The specificity of the nuclear proteins-GRE interaction was demonstrated by competition experiments with unlabelled GRE. In a supershift assay, using the antibody BuGR2, it was shown that the GR proteins present in nuclear extracts have a high affinity for the GRE probe. The stabilities of the protein-DNA complexes were analysed and it was concluded that they changed during ageing. .

scholarly journals Branched-Chain Fatty Acids as Mediators of the Activation of Hepatic Peroxisome Proliferator-Activated Receptor Alpha by a Fungal Lipid Extract

Biomolecules ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1259 ◽  
Author(s):  
Garima Maheshwari ◽  
Robert Ringseis ◽  
Gaiping Wen ◽  
Denise K. Gessner ◽  
Johanna Rost ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Reporter Gene ◽  
Target Genes ◽  
Reporter Gene Assay ◽  
Lipid Extract ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Branched Chain Fatty Acids ◽  
Gene Assay ◽  
Branched Chain

The study aimed to test the hypothesis that monomethyl branched-chain fatty acids (BCFAs) and a lipid extract of Conidiobolus heterosporus (CHLE), rich in monomethyl BCFAs, are able to activate the nuclear transcription factor peroxisome proliferator-activated receptor alpha (PPARalpha). Rat Fao cells were incubated with the monomethyl BCFAs 12-methyltridecanoic acid (MTriA), 12-methyltetradecanoic acid (MTA), isopalmitic acid (IPA) and 14-methylhexadecanoic acid (MHD), and the direct activation of PPARalpha was evaluated by reporter gene assay using a PPARalpha responsive reporter gene. Furthermore, Fao cells were incubated with different concentrations of the CHLE and PPARalpha activation was also evaluated by using the reporter gene assay, and by determining the mRNA concentrations of selected PPARalpha target genes by real-time RT-PCR. The reporter gene assay revealed that IPA and the CHLE, but not MTriA, MHD and MTA, activate the PPARalpha responsive reporter gene. CHLE dose-dependently increased mRNA concentrations of the PPARalpha target genes acyl-CoA oxidase (ACOX1), cytochrome P450 4A1 (CYP4A1), carnitine palmitoyltransferase 1A (CPT1A) and solute carrier family 22 (organic cation/carnitine transporter), member 5 (SLC22A5). In conclusion, the monomethyl BCFA IPA is a potent PPARalpha activator. CHLE activates PPARalpha-dependent gene expression in Fao cells, an effect that is possibly mediated by IPA.

scholarly journals DNA-binding activity in the excretory–secretory products ofTrichinella pseudospiralis(Nematoda: Trichinelloidea)

Parasitology ◽  
2001 ◽  
Vol 123 (3) ◽  
pp. 301-308 ◽  
Author(s):  
C. H. MAK ◽  
R. C. KO
Keyword(s):  
Dna Binding ◽  
Electrophoretic Mobility ◽  
Protein Complexes ◽  
Binding Activity ◽  
Mobility Shift ◽  
Competition Analysis ◽  
Dna Binding Activity ◽  
Supershift Assay ◽  
Mobility Shift Assay ◽  
Secretory Products

A novel DNA-binding peptide ofMr∼30 kDa was documented for the first time in the excretory–secretory (E–S) products of the infective-stage larvae ofTrichinella pseudospiralis.Larvae recovered from muscles of infected mice were maintained for 48 h in DMEM medium. E–S products of worms extracted from the medium were analysed for DNA-binding activity by the electrophoretic mobility shift assay (EMSA). Multiple DNA-protein complexes were detected. A comparison of theMrof proteins in the complexes indicated that they could bind to the target DNA as a dimer, tetramer or multiples of tetramers. Site selection and competition analysis showed that the binding has a low specificity. A (G/C-rich)-gap-(G/T-rich)-DNA sequence pattern was extracted from a pool of degenerate PCR fragments binding to the E–S products. Results of immunoprecipitation and electrophoretic mobility supershift assay confirmed the authenticity of the DNA-binding protein as an E–S product.

scholarly journals The retinoblastoma gene product RB stimulates Sp1-mediated transcription by liberating Sp1 from a negative regulator.

1994 ◽  
Vol 14 (7) ◽  
pp. 4380-4389 ◽  
Author(s):  
L I Chen ◽  
T Nishinaka ◽  
K Kwan ◽  
I Kitabayashi ◽  
K Yokoyama ◽  
...  
Keyword(s):  
Dna Binding ◽  
Gene Product ◽  
Binding Activity ◽  
Negative Regulator ◽  
Control Element ◽  
Dependent Manner ◽  
Mobility Shift ◽  
Dna Binding Activity ◽  
Cell Extracts ◽  
Mobility Shift Assay

Studies have demonstrated that the retinoblastoma susceptibility gene product, RB, can either positively or negatively regulate expression of several genes through cis-acting elements in a cell-type-dependent manner. The nucleotide sequence of the retinoblastoma control element (RCE) motif, GCCACC or CCACCC, and the Sp1 consensus binding sequence, CCGCCC, can confer equal responsiveness to RB. Here, we report that RB activates transcription of the c-jun gene through the Sp1-binding site within the c-jun promoter. Preincubation of crude nuclear extracts with monoclonal antibodies to RB results in reduction of Sp1 complexes in a mobility shift assay, while addition of recombinant RB in mobility shift assay mixtures with CCL64 cell extracts leads to an enhancement of DNA-binding activity of SP1. These results suggest that RB is directly or indirectly involved in Sp1-DNA binding activity. A mechanism by which RB regulates transactivation is indicated by our detection of a heat-labile and protease-sensitive Sp1 negative regulator(s) (Sp1-I) that specifically inhibits Sp1 binding to a c-jun Sp1 site. This inhibition is reversed by addition of recombinant RB proteins, suggesting that RB stimulates Sp1-mediated transactivation by liberating Sp1 from Sp1-I. Additional evidence for Sp1-I involvement in Sp1-mediated transactivation was demonstrated by cotransfection of RB, GAL4-Sp1, and a GAL4-responsive template into CV-1 cells. Finally, we have identified Sp1-I, a approximately 20-kDa protein(s) that inhibits the Sp1 complexes from binding to DNA and that is also an RB-associated protein. These findings provide evidence for a functional link between two distinct classes of oncoproteins, RB and c-Jun, that are involved in the control of cell growth, and also define a novel mechanism for the regulation of c-jun expression.

PGC-1α coactivates estrogen-related receptor-α to induce the expression of glucokinase

2010 ◽  
Vol 298 (6) ◽  
pp. E1210-E1218 ◽  
Author(s):  
Liu-Luan Zhu ◽  
Yang Liu ◽  
An-Fang Cui ◽  
Di Shao ◽  
Ji-Chao Liang ◽  
...  
Keyword(s):  
Enzyme Regulation ◽  
Regulatory Function ◽  
Acid Oxidation ◽  
Regulatory Sequence ◽  
Peroxisome Proliferator ◽  
Mobility Shift ◽  
Glucokinase Gene ◽  
Peroxisome Proliferator Activated Receptor ◽  
Insulin Dependent ◽  
Novel Target

Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) is a key regulator of cellular energy metabolism and regulates processes such as adaptive thermogenesis, hepatic gluconeogenesis, fatty acid oxidation, and mitochondrial biogenesis by coactivating numerous nuclear receptors and transcription factors. Here, we demonstrate the presence of the ERRα binding site in the regulatory sequence of the glucokinase gene and that PGC-1α coactivates ERRα to stimulate the transcription of glucokinase. Simultaneous overexpression of PGC-1α and ERRα potently induced the glucokinase gene expression and its enzymatic activity in primary hepatocytes; however, expression of either PGC-1α or ERRα alone had no significant effect. Electrophoretic mobility shift and chromatin immunoprecipitation assays revealed the interaction of ERRα with the glucokinase promoter. Finally, the knockdown of endogenous ERRα with specific siRNA (siERRα) or pharmacological inhibition of ERRα with XCT790 attenuated insulin-induced glucokinase expression. Taken together, this research identifies glucokinase as a novel target of PGC-1α/ERRα and underscores the regulatory function of ERRα in insulin-dependent enzyme regulation.

scholarly journals Apolipoprotein H Promoter Polymorphisms in Relation to Lupus and Lupus-related Phenotypes

2009 ◽  
Vol 36 (2) ◽  
pp. 315-322 ◽  
Author(s):  
SANGITA SURESH ◽  
F. YESIM K. DEMIRCI ◽  
ERIN JACOBS ◽  
AMY H. KAO ◽  
ELISA Y. RHEW ◽  
...  
Keyword(s):  
Lupus Erythematosus ◽  
Disease Risk ◽  
Gene Promoters ◽  
Nucleotide Polymorphisms ◽  
Promoter Polymorphisms ◽  
Mobility Shift ◽  
Association Analyses ◽  
Gene Assay ◽  
Mobility Shift Assay

Objective.Sequence variation in gene promoters is often associated with disease risk. We tested the hypothesis that common promoter variation in the APOH gene (encoding for ß2-glycoprotein I) is associated with systemic lupus erythematosus (SLE) risk and SLE-related clinical phenotypes in a Caucasian cohort.Methods.We used a case-control design and genotyped 345 women with SLE and 454 healthy control women for 8APOHpromoter single-nucleotide polymorphisms (SNP; –1284C>G, –1219G>A, –1190G>C, –759A>G, –700C>A, –643T>C, –38G>A, and –32C>A).Association analyses were performed on single SNP and haplotypes. Haplotype analyses were performed using EH (Estimate Haplotype–frequencies) and Haploview programs.In vitroreporter gene assay was performed in COS-1 cells. Electrophoretic mobility shift assay (EMSA) was performed using HepG2 nuclear cells.Results.Overall haplotype distribution of theAPOHpromoter SNP was significantly different between cases and controls (p = 0.009). The –643C allele was found to be protective against carotid plaque formation (adjusted OR 0.37, p = 0.013) among patients with SLE. The –643C allele was associated with a ~2-fold decrease in promoter activity as compared to wild-type –643T allele (mean ± standard deviation: 3.94 ± 0.05 vs 6.99 ± 0.68, p = 0.016). EMSA showed that the –643T>C SNP harbors a binding site for a nuclear factor. The –1219G>A SNP showed a significant association with the risk of lupus nephritis (age-adjusted OR 0.36, p = 0.016).Conclusion.Our data indicate thatAPOHpromoter variants may be involved in the etiology of SLE, especially the risk for autoimmune-mediated cardiovascular disease.

scholarly journals Activation of Peroxisome Proliferator-Activated Receptor Gamma by Human Cytomegalovirus for De Novo Replication Impairs Migration and Invasiveness of Cytotrophoblasts from Early Placentas

2009 ◽  
Vol 84 (6) ◽  
pp. 2946-2954 ◽  
Author(s):  
Benjamin Rauwel ◽  
Bernard Mariamé ◽  
Hélène Martin ◽  
Ronni Nielsen ◽  
Sophie Allart ◽  
...  
Keyword(s):  
Human Cytomegalovirus ◽  
De Novo ◽  
Present Report ◽  
Primary Cultures ◽  
First Trimester ◽  
Peroxisome Proliferator ◽  
Mobility Shift ◽  
Peroxisome Proliferator Activated Receptor ◽  
Human Trophoblast

ABSTRACT Human cytomegalovirus (HCMV) contributes to pathogenic processes in immunosuppressed individuals, in fetuses, and in neonates. In the present report, by using reporter gene activation assays and confocal microscopy in the presence of a specific antagonist, we show for the first time that HCMV infection induces peroxisome proliferator-activated receptor gamma (PPARγ) transcriptional activity in infected cells. We demonstrate that the PPARγ antagonist dramatically impairs virus production and that the major immediate-early promoter contains PPAR response elements able to bind PPARγ, as assessed by electrophoretic mobility shift and chromatin immunoprecipitation assays. Due to the key role of PPARγ in placentation and its specific trophoblast expression within the human placenta, we then provided evidence that by activating PPARγ human cytomegalovirus dramatically impaired early human trophoblast migration and invasiveness, as assessed by using well-established in vitro models of invasive trophoblast, i.e., primary cultures of extravillous cytotrophoblasts (EVCT) isolated from first-trimester placentas and the EVCT-derived cell line HIPEC. Our data provide new clues to explain how early infection during pregnancy could impair implantation and placentation and therefore embryonic development.

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