scholarly journals p54nrb Is a Transcriptional Corepressor of the Progesterone Receptor that Modulates Transcription of the Labor-Associated Gene, Connexin 43 (Gja1)

2009 ◽  
Vol 23 (8) ◽  
pp. 1147-1160 ◽  
Author(s):  
Xuesen Dong ◽  
Celeste Yu ◽  
Oksana Shynlova ◽  
John R. G. Challis ◽  
Paul S. Rennie ◽  
...  

Abstract The progesterone receptor (PR) plays important roles in the establishment and maintenance of pregnancy. By dynamic interactions with coregulators, PR represses the expression of genes that increase the contractile activity of myometrium and contribute to the initiation of labor. We have previously shown that PTB-associated RNA splicing factor (PSF) can function as a PR corepressor. In this report, we demonstrated that the PSF heterodimer partner, p54nrb (non-POU-domain-containing, octamer binding protein), can also function as a transcription corepressor, independent of PSF. p54nrb Interacts directly with PR independent of progesterone. In contrast to PSF, p54nrb neither enhances PR protein degradation nor blocks PR binding to DNA. Rather, p54nrb recruits mSin3A through its N terminus to the PR-DNA complex, resulting in an inhibition of PR-mediated transactivation of the progesterone-response element-luciferase reporter gene. PR also repressed transcription of the connexin 43 gene (Gja1), an effect dependent on the presence of an activator protein 1 site within the proximal Gja1 promoter. Mutation of this site abolished PR-mediated repression and decreased the recruitment of PR and p54nrb onto the Gja1 promoter. Furthermore, knockdown p54nrb expression by small interfering RNA alleviated PR-mediated repression on Gja1 transcription, whereas overexpression of p54nrb enhanced it. In the physiological context of pregnancy, p54nrb protein levels decrease with the approach of labor in the rat myometrium. We conclude that p54nrb is a transcriptional corepressor of PR. Decreased expression of p54nrb at the time of labor may act to derepress PR-mediated inhibition on connexin 43 expression and contribute to the initiation of labor.

1999 ◽  
Vol 276 (5) ◽  
pp. F786-F793 ◽  
Author(s):  
Zheng Zhang ◽  
Xiao-Yan Yang ◽  
David M. Cohen

Urea treatment (100–300 mM) increased expression of the oxidative stress-responsive transcription factor, Gadd153/CHOP, at the mRNA and protein levels (at ≥4 h) in renal medullary mIMCD3 cells in culture, whereas other solutes did not. Expression of the related protein, CCAAT/enhancer-binding protein (C/EBP-β), was not affected, nor was expression of the sensor of endoplasmic reticulum stress, grp78. Urea modestly increased Gadd153 transcription by reporter gene analysis but failed to influence Gadd153 mRNA stability. Importantly, upregulation of Gadd153 mRNA and protein expression by urea was antioxidant sensitive. Accordingly, urea treatment was associated with oxidative stress, as quantitated by intracellular reduced glutathione content in mIMCD3 cells. In addition, antioxidant treatment partially inhibited the ability of urea to activate transcription of an Egr-1 luciferase reporter gene. Therefore oxidative stress represents a novel solute-signaling pathway in the kidney medulla and, potentially, in other tissues.


2020 ◽  
Vol 160 (2) ◽  
pp. 63-71
Author(s):  
Yunxiao Li ◽  
Xugang Shi ◽  
Xintong Cai ◽  
Yongsheng Zhu ◽  
Yuanyuan Chen ◽  
...  

DCC netrin 1 receptor (DCC) affects the structure and function of the dopamine circuitry, which in turn affects the susceptibility to developing addiction. In a previous study, we found that single nucleotide polymorphism (SNP) rs12607853 in the 3′ untranslated region (3′-UTR) of DCC was significantly associated with heroin addiction. In the current study, we first used bioinformatics prediction to identify the DCC rs12607853 C allele as a potential hsa-miR-422a and hsa-miR-378c target site. We then used vector construction and dual-luciferase reporter assays to investigate the targeting relationship of DCC rs12607853 with hsa-miR-422a and hsa-miR-378c. The dual-luciferase reporter gene assay confirmed that the C allele of rs12607853 in combination with hsa-miR-422a led to repressed dual-luciferase gene expression. Moreover, gene expression assays disclosed that hsa-miR-422a inhibited DCC expression at both the mRNA and protein levels. We also found that morphine inhibited the expression of hsa-miR-422a but increased the expression of DCC mRNA, and this change in the expression of hsa-miR-422a could not be reversed by naloxone, which suggested that the role of DCC in opioid addiction might be regulated by hsa-miR-422a. In summary, this study improves our understanding of the role of hsa-miR-422a and identifies the genetic basis of rs12607853, which might contribute to the discovery of new biomarkers or therapeutic targets for opioid addiction.


2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Wen Zhang ◽  
Dan Shen ◽  
Yun Li ◽  
Hong Zhong ◽  
Xing Wang ◽  
...  

Abstract Background Obesity is a global epidemic disease that increases the risk of metabolic syndrome. However, therapeutic drugs for obesity are still scarce. In recent years, peptides have been identified as new biological regulators. RIFV (R-I-F-V-P-I-K-G-R-P-A-P), a novel active peptide from our peptide database. Methods We performed oil red O staining and triglyceride measurement to analyze the influence of RIFV on white preadipocytes differentiation. Then the effects of RIFV on cell proliferation, apoptosis and cell cycle were determined by using CCK-8 assay and flow cytometry. The mRNA and protein levels of adipogenesis-related genes were respectively detected by qRT-PCR and western blot. Rescue experiment was conducted to confirm whether RIFV could regulate adipocytes differentiation via targeting C/EBP-β. Finally, the luciferase reporter gene assay was performed to verify the regulation of RIFV on C/EBP-β gene. Results RIFV was revealed to inhibit the differentiation of human white adipocytes without affecting their proliferation. Additionally, RIFV could also suppress the differentiation of mouse primary white preadipocytes isolated from inguinal fat tissues. Furthermore, RIFV may have an inhibitory effect on adipogenesis by inhibiting the regulation of the adipogenic gene C/EBP-β. Conclusions Our results indicated that RIFV may be a novel essential regulator of adipocyte differentiation and represents a therapeutic strategy for obesity and related complications.


Cells ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1532 ◽  
Author(s):  
Ning Li ◽  
Joachim F. Uhrig ◽  
Corinna Thurow ◽  
Li-Jun Huang ◽  
Christiane Gatz

The phytohormone jasmonic acid (JA) plays an important role in various plant developmental processes and environmental adaptations. The JA signaling pathway has been well-elucidated in the reference plant Arabidopsis thaliana. It starts with the perception of the active JA derivative, jasmonoyl-isoleucine (JA-Ile), by the F-box protein COI1 which is part of the E3-ligase SCFCOI1. Binding of JA-Ile enables the interaction between COI1 and JAZ repressor proteins. Subsequent degradation of JAZ proteins leads to the activation of transcription factors like e.g., MYC2. Here we demonstrate that the pathway can be reconstituted in transiently transformed protoplasts. Analysis of the stability of a JAZ1-fLuc fusion protein as a function of COI1 transiently expressed in coi1 protoplasts allows structure function analysis of both JAZs and COI1. Using this system, we found that conserved cysteines in COI1 influence steady state COI1 protein levels. Using a luciferase reporter gene under the control of the JAZ1 promoter enable to address those features of JAZ1 that are required for MYC2 repression. Interestingly, the conserved TIFY-motif previously described to interact with NINJA to recruit the corepressor TOPLESS is not necessary for repression. This result is in favor of the alternative repression mode that proposes a direct competition between repressive JAZs and promotive MEDIATOR25 at MYC2. Finally, using protoplasts from the aos coi1 double mutant, which is deficient in JA synthesis and perception, we provide a system that has the potential to study the activity of different COI1 variants in the presence of different ligands.


2018 ◽  
Vol 36 (4_suppl) ◽  
pp. 307-307
Author(s):  
Mei-Juan Tu ◽  
Zhijian Duan ◽  
Qianyu Zhang ◽  
Jing-Xin Qiu ◽  
Frank J Gonzalez ◽  
...  

307 Background: MicroRNAs (miR) have proved to be vital regulators in the control of tumor progression. Our recent studies have revealed miR-1291 is downregulated in patient pancreatic cancer (PC) specimens and re-introduction of miR-1291 suppresses tumorigenesis of PC cells. We have developed a novel ncRNA bioengineering technology to produce a miR-1291 prodrug. In this study, we aimed to assess the effectiveness of this miR-1291 prodrug as a monotherapy, as well as in combination with chemotherapy, for treatment of PC. Methods: Sensitivity of PC cells to miR-1291 prodrug alone, gemcitabine plus nab-paclitaxel (Gem-nP) alone, and their combination was evaluated by CellTiter-Glo assay. Mature miR-1291 and ARID3B mRNA levels were determined by quantitative real-time PCR (q-PCR) assay. A luciferase reporter gene assay was used to validate interaction between miR-1291 and ARID3B 3’UTR. Target protein expression was examined by Western blot and immunofluorescence analyses. PANC-1 and PC patient-derived xenograft (PDX) mouse models were established and used to assess anti-tumor effects of miR-1291 monotherapy and combination therapy with Gem-nP. Results: Cytotoxicity assays showed that miR-1291 prodrug enhanced the sensitivity of PANC-1 and AsPC-1 cells to Gem-nP. Luciferase assays confirmed ARID3B as a target for miR-1291 as predicted by computational analysis. qPCR analysis demonstrated that miR-1291 prodrug was readily processed to mature miR-1291 and subsequently upregulated ARID3B mRNA levels. miR-1291 prodrug also elevated the protein levels of ARID3B. Co-administration of miR-1291 prodrug and Gem-nP increased caspase-3/7 and γH2AX levels in PC cells, compared to miR-1291 or Gem-nP treatment alone. In addition, systemic administration of in vivo-jet PEI formulated miR-1291 prodrug suppressed tumor growth in both a PANC-1 xenograft model and three PDX models, and largely enhanced the efficacy of Gem-nP. All treatments were well tolerated in mice in vivo. Conclusions: Our bioengineered miR-1291 prodrug has therapeutic potential as a monotherapy but also can act as a sensitizing agent to chemotherapy. This novel treatment approach should be further explored for PC.


2002 ◽  
Vol 368 (2) ◽  
pp. 573-580 ◽  
Author(s):  
Toby W. HURD ◽  
Ainsley A. CULBERT ◽  
Kenneth J. WEBSTER ◽  
Jeremy M. TAVARÉ

Insulin regulates the activity of the AP-1 (activator protein-1) transcriptional complex in several cell types. One component of the AP-1 complex is the transcription factor Fra-1 (fos-related antigen-1), and we have demonstrated previously that insulin stimulates the expression of Fra-1 mRNA in CHO.T cells [Griffiths, Black, Culbert, Dickens, Shaw, Gillespie and Tavaré (1998) Biochem. J. 335, 19—26]. Here we demonstrate that insulin stimulates the activity of a fra-1 promoter linked to a luciferase reporter gene, indicating that the ability of insulin to induce expression of Fra-1 mRNA is due, at least in part, to an increase in gene transcription. Furthermore, we found that insulin induces the serine phosphorylation of Fra-1 and reduces its mobility during SDS/PAGE as a result of phosphorylation. The ability of insulin to induce the accumulation of Fra-1 mRNA, stimulate the fra-1 promoter and stimulate phosphorylation of Fra-1 all require the mitogen-activated protein (MAP) kinase cascade, which leads to the activation of extracellular-signal-regulated kinase (Erk) 1/2. Consequently, our results demonstrate that the Erk cascade plays a dual role in the co-ordinated regulation of the transcription and the phosphorylation of Fra-1 by insulin.


2010 ◽  
Vol 105 (2) ◽  
pp. 167-170 ◽  
Author(s):  
Charlotte Schrader ◽  
Christina Schiborr ◽  
Jan Frank ◽  
Gerald Rimbach

Paraoxonase 1 (PON1) is an enzyme that is mainly synthesised in the liver and protects LDL from oxidation, thereby exhibiting antiatherogenic properties. Using a luciferase reporter gene assay, we tested curcumin for its ability to induce PON1 in Huh7 hepatocytes in culture. Curcumin ( ≥ 10 μmol/l) dose-dependently induced PON1 transactivation in Huh7 cells. However, dietary supplementation of female B6C3F1 mice with curcumin (500 mg/kg diet) for 2 weeks did not increase the hepatic PON1 mRNA and protein levels. No curcumin was detectable in the plasma of the 12 h fasted mice. In conclusion, curcumin may be a potent PON1 inducer in cultured cells in vitro, but not in the liver of curcumin-fed mice because of its low concentrations in vivo.


2008 ◽  
Vol 417 (1) ◽  
pp. 235-246 ◽  
Author(s):  
Sonja Hägele ◽  
Uwe Kühn ◽  
Melanie Böning ◽  
Dörthe M. Katschinski

The heterodimeric HIF (hypoxia-inducible factor)-1 is a transcriptional master regulator of several genes involved in mammalian oxygen homoeostasis. Besides the well described regulation of the HIF-1α subunit via hydroxylation-mediated protein stability in hypoxia, there are several indications of an additional translational control of the HIF-1α mRNA, especially after growth factor stimulation. We identified an interaction of CPEB (cytoplasmic polyadenylation-element-binding protein) 1 and CPEB2 with the 3′-UTR (untranslated region) of HIF-1α mRNA. Overexpression of CPEB1 and CPEB2 affected HIF-1α protein levels mediated by the 3′-UTR of HIF-1α mRNA. Stimulation of neuroblastoma SK-N-MC cells with insulin and thus activation of endogenous CPEBs increased the expression of a luciferase reporter gene fused to the 3′-UTR of HIF-1α as well as endogenous HIF-1α protein levels. This could be abrogated by treating the cells with CPEB1 or CPEB2 siRNAs (short interfering RNAs). Injection of HIF-1α cRNA into Xenopus oocytes verified the elongation of the poly(A)+ (polyadenylated) tail by cytoplasmic polyadenylation. Thus CPEB1 and CPEB2 are involved in the regulation of HIF-1α following insulin stimulation.


2020 ◽  
Author(s):  
Dandan Li ◽  
Yang Liu ◽  
Wei Gao ◽  
Jiakai Han ◽  
Rongrong Yuan ◽  
...  

Abstract Background: LncRNAs have been discovered to play a key role in adipogenesis, vital in regulating adipose developmen t. Numerous evidences show that adipogenesis is the leading cause of obesity, while the role of lncRNA HLA complex group 11 ( HCG11 ) in adipocyte differentiation has not been elucidated. Methods: hAdMSCs were used to establish a model of cell differentiation in vitro . Expression of lncRNA HCG11 was detected by RT-qPCR analysis. Transfection of the shRNA targeting HCG11 or pcDNA-HCG11 into hAdMSCs was also assessed. The adipogenic marker proteins C/EBPα, FABP4 and PPARγ2 and important inflammatory factors IL-6 and TNF-α were detected by Western blot. Bioinformatics analysis predicted the target genes of HCG11 and mir-204-5p, which was confirmed by luciferase reporter gene analysis and RNA pull-down analysis. Results: Here we show that lncRNA HCG11 was decreased as the degree of adipogenesis. The expression of C/EBPα, FABP4 and PPARγ2 were significantly downregulated transfected with pcDNA-HCG11 in hAdMSCs at different stages, while knockdown lncRNA HCG11 can promote adipocyte differentiation. In addition, miR-204-5p was a potential target gene of HCG11 and SIRT1 could directly target miR-204-5p. Overexpression of SIRT1 or transfected with agonists of SIRT1 (Res) significantly inhibited adipogenic marker protein levels and inflammatory responses, and the proliferation of hAdMSCs were also inhibited. pcDNA-HCG11 and miR-204-5p mimic were co-transfected into hAdMSCs, we found that miR-204-5p mimic reversed the suppressor effect of pcDNA-HCG11. Conclusion: Our findings showed that HCG11 negatively regulated cell proliferation, inflammatory responses and adipogenesis by miR-204-5p/SIRT1 axis. And our findings may provide a new target for the study of adipogenesis in hAdMSCs and obesity.


PLoS Biology ◽  
2021 ◽  
Vol 19 (5) ◽  
pp. e3001221
Author(s):  
Sara Hosseini-Farahabadi ◽  
Alireza Baradaran-Heravi ◽  
Carla Zimmerman ◽  
Kunho Choi ◽  
Stephane Flibotte ◽  
...  

Premature termination codons (PTC) cause over 10% of genetic disease cases. Some aminoglycosides that bind to the ribosome decoding center can induce PTC readthrough and restore low levels of full-length functional proteins. However, concomitant inhibition of protein synthesis limits the extent of PTC readthrough that can be achieved by aminoglycosides like G418. Using a cell-based screen, we identified a small molecule, the phenylpyrazoleanilide Y-320, that potently enhances TP53, DMD, and COL17A1 PTC readthrough by G418. Unexpectedly, Y-320 increased cellular protein levels and protein synthesis, measured by SYPRO Ruby protein staining and puromycin labeling, as well as ribosome biogenesis measured using antibodies to rRNA and ribosomal protein S6. Y-320 did not increase the rate of translation elongation and it exerted its effects independently of mTOR signaling. At the single cell level, exposure to Y-320 and G418 increased ribosome content and protein synthesis which correlated strongly with PTC readthrough. As a single agent, Y-320 did not affect translation fidelity measured using a luciferase reporter gene but it enhanced misincorporation by G418. RNA-seq data showed that Y-320 up-regulated the expression of CXC chemokines CXCL10, CXCL8, CXCL2, CXCL11, CXCL3, CXCL1, and CXCL16. Several of these chemokines exert their cellular effects through the receptor CXCR2 and the CXCR2 antagonist SB225002 reduced cellular protein levels and PTC readthrough in cells exposed to Y-320 and G418. These data show that the self-limiting nature of PTC readthrough by G418 can be compensated by Y-320, a potent enhancer of PTC readthrough that increases ribosome biogenesis and protein synthesis. They also support a model whereby increased PTC readthrough is enabled by increased protein synthesis mediated by an autocrine chemokine signaling pathway. The findings also raise the possibility that inflammatory processes affect cellular propensity to readthrough agents and that immunomodulatory drugs like Y-320 might find application in PTC readthrough therapy.


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