scholarly journals Identification of a signal transducer and activator of transcription (STAT) binding site in the mouse metallothionein-I promoter involved in interleukin-6-induced gene expression

1998 ◽  
Vol 337 (1) ◽  
pp. 59-65 ◽  
Author(s):  
Dae Kee LEE ◽  
Javier CARRASCO ◽  
Juan HIDALGO ◽  
Glen K. ANDREWS
Keyword(s):  
Gene Expression ◽  
Binding Site ◽  
Time Course ◽  
Proximal Promoter ◽  
Type I ◽  
Mobility Shift ◽  
Knock Out ◽  
I Gene

Mechanisms of regulation of mouse metallothionein (MT)-I gene expression in response to bacterial endotoxin-lipopolysaccharide (LPS) were examined. Northern blot analysis of hepatic MT-I mRNA in interleukin (IL)-6 or tumour necrosis factor (TNF)-receptor type I knock-out mice demonstrated that IL-6, not TNF-α, is of central importance in mediating hepatic MT-I gene expression in vivo after LPS injection. In vivo genomic footprinting of the MT-I promoter demonstrated a rapid increase, after LPS injection, in the protection of several guanine residues in the -250 to -300 bp region of the MT-I promoter. The protected bases were within sequences which resemble binding sites for the signal transducers and activators of transcription (STAT) transcription factor family. Electrophoretic mobility-shift assays using oligonucleotides from footprinted MT-I promoter regions showed that injection of LPS resulted in a rapid increase in the specific, high-affinity, in vitro binding of STAT1 and STAT3 to a binding site at -297 bp (TTCTCGTAA). Western blotting of hepatic nuclear proteins showed that the time-course for changes of total nuclear STAT1 and STAT3 after LPS injection paralleled the increased complex formation in vitro using this oligonucleotide, and binding was specifically competed for by a functional STAT-binding site from the rat α2-macroglobulin promoter. Furthermore, the MT-I promoter -297 bp STAT-binding site conferred IL-6 responsiveness in the context of a minimal promoter in transient transfection assays using HepG2 cells. This study suggests that the effects of LPS on hepatic MT-I gene expression are mediated by IL-6 and involve the activation of STAT-binding to the proximal promoter.

Transcriptional regulation mechanisms of hypoxia-induced neuroglobin gene expression

2012 ◽  
Vol 443 (1) ◽  
pp. 153-164 ◽  
Author(s):  
Ning Liu ◽  
Zhanyang Yu ◽  
Shuanglin Xiang ◽  
Song Zhao ◽  
Anna Tjärnlund-Wolf ◽  
...  
Keyword(s):  
Gene Expression ◽  
Hypoxia Inducible Factor ◽  
Gene Promoter ◽  
Nuclear Factor Κb ◽  
Proximal Promoter ◽  
Mobility Shift ◽  
Hypoxic Conditions ◽  
Mobility Shift Assay

Ngb (neuroglobin) has been identified as a novel endogenous neuroprotectant. However, little is known about the regulatory mechanisms of Ngb expression, especially under conditions of hypoxia. In the present study, we located the core proximal promoter of the mouse Ngb gene to a 554 bp segment, which harbours putative conserved NF-κB (nuclear factor κB)- and Egr1 (early growth-response factor 1) -binding sites. Overexpression and knockdown of transcription factors p65, p50, Egr1 or Sp1 (specificity protein 1) increased and decreased Ngb expression respectively. Experimental assessments with transfections of mutational Ngb gene promoter constructs, as well as EMSA (electrophoretic mobility-shift assay) and ChIP (chromatin immunoprecipitation) assays, demonstrated that NF-κB family members (p65, p50 and cRel), Egr1 and Sp1 bound in vitro and in vivo to the proximal promoter region of the Ngb gene. Moreover, a κB3 site was found as a pivotal cis-element responsible for hypoxia-induced Ngb promoter activity. NF-κB (p65) and Sp1 were also responsible for hypoxia-induced up-regulation of Ngb expression. Although there are no conserved HREs (hypoxia-response elements) in the promoter of the mouse Ngb gene, the results of the present study suggest that HIF-1α (hypoxia-inducible factor-1α) is also involved in hypoxia-induced Ngb up-regulation. In conclusion, we have identified that NF-κB, Egr1 and Sp1 played important roles in the regulation of basal Ngb expression via specific interactions with the mouse Ngb promoter. NF-κB, Sp1 and HIF-1α contributed to the up-regulation of mouse Ngb gene expression under hypoxic conditions.

Tissue specificity of type I collagen gene expression is determined at both transcriptional and post-transcriptional levels

1984 ◽  
Vol 4 (9) ◽  
pp. 1843-1852
Author(s):  
R J Focht ◽  
S L Adams
Keyword(s):  
Gene Expression ◽  
Rna Structure ◽  
Type I Collagen ◽  
Translational Efficiency ◽  
Type I ◽  
Collagen Gene ◽  
Differentiated Cells ◽  
Collagen Gene Expression

We analyzed the control of type I collagen synthesis in four kinds of differentiated cells from chicken embryos which synthesize very different amounts of the protein. Tendon, skin, and smooth muscle cells were found to have identical amounts of type I collagen RNAs; however, the RNAs had inherently different translatabilities, which were observed both in vivo and in vitro. Chondrocytes also had substantial amounts of type I collagen RNAs, even though they directed no detectable synthesis of the protein either in vivo or in vitro. Type I collagen RNAs in chondrocytes display altered electrophoretic mobilities, suggesting that in these cells the reduction in translational efficiency may be mediated in part by changes in the RNA structure. These data indicate that control of type I collagen gene expression is a complex process which is exerted at both transcriptional and post-transcriptional levels.

scholarly journals In Vitro and in Vivo Calcitonin I Gene Expression in Parenchymal Cells: A Novel Product of Human Adipose Tissue

Endocrinology ◽  
2003 ◽  
Vol 144 (12) ◽  
pp. 5578-5584 ◽  
Author(s):  
Philippe Linscheid ◽  
Dalma Seboek ◽  
Eric S. Nylen ◽  
Igor Langer ◽  
Mirjam Schlatter ◽  
...  
Keyword(s):  
Gene Expression ◽  
Adipose Tissue ◽  
Human Adipose Tissue ◽  
Parenchymal Cells ◽  
I Gene

The role of NeuroD1 in the upregulation of SMYD3 by HBx.

2012 ◽  
Vol 30 (4_suppl) ◽  
pp. 183-183
Author(s):  
Junyao Xu ◽  
Qingqi Hong ◽  
Chuanchao He ◽  
Jie Wang
Keyword(s):  
Gene Expression ◽  
Binding Site ◽  
Promoter Region ◽  
Gene Transfection ◽  
Histone Methyltransferase ◽  
Proximal Promoter ◽  
Luciferase Reporter ◽  
Mobility Shift ◽  
Cis Element ◽  
E Box

183 Background: SET and MYND Domain-Containing Protein 3 (SMYD3) is frequently overexpressed in hepatocellular carcinoma (HCC) exhibiting increased malignant phenotypes. It has also been known that the hepatitis B virus x protein (HBx) is strongly associated with HCC development and progression. Although overexpression of both proteins is related to HCC, the relationship between the two has not been well studied. Methods: Immunohistochemical staining was used to detect the expression of HBx and SMYD3 in HCC tumor tissues. HBx gene transfection, RNAi, and histone methyltransferase(H3-K4) activity assay were performed to reveal the transcrpitionally activation of HBx on functional SMYD3 gene expression. Chromatin immunoprecipitation (ChIP), Co-immunoprecipitation (Co-IP), Electrophoretic mobility shift assay (EMSA) were applied to investigate the underlying mechanism. Dual-luciferase reporter assay was used to search for the HBx responsive cis-element of SMYD3 gene. Results: Immunohistochemistry identified the positive correlation between HBx and SMYD3 expression in 42 HCC tissues. Up-regulation of HBx on SMYD3 expression was validated through experiments involving overexpression or knock-down of HBx in different HCC cell lines. And up-regulated SMYD3 is functionally active as histone methyltransferase. Next we found that HBx transcriptionally regulated SMYD3 gene expression by interacting with RNA polymerase IIand altering its binding site to a proximal promoter region(SD2) from a distant promoter region(SD6) of SMYD3. Truncated and mutant reporter assays revealed that the cis-element mapped in -178~-203bp in SMYD3 promotor is responsive for HBx-transactivation. And this 25bp cis-element contains a E-box 3 unit, which is a binding site for the transcriptional factor Neurogenic differentiation 1(NeuroD1). EMSA and Chip showed that HBx increased NeuroD1 binding to SMYD3 proximal promotor, however transcient expression of antisense NeuroD1 abolished HBx-induced SMYD3 expression. Conclusions: HBx transcriptionally up-regulates SMYD3 and that this process is mediated by NeuroD1 through binding to the E-box 3 site of SMYD3 promotor.

scholarly journals Identification of an Adeno-Associated Virus Rep Protein Binding Site in the Adenovirus E2a Promoter

2005 ◽  
Vol 79 (1) ◽  
pp. 28-38 ◽  
Author(s):  
John M. Casper ◽  
Jennifer M. Timpe ◽  
John David Dignam ◽  
James P. Trempe
Keyword(s):  
Gene Expression ◽  
Random Sequence ◽  
Gene Promoter ◽  
Helper Virus ◽  
Host Cells ◽  
Mobility Shift ◽  
Adeno Associated Virus ◽  
Rep Protein

ABSTRACT Adeno-associated virus (AAV) and other parvoviruses inhibit proliferation of nonpermissive cells. The mechanism of this inhibition is not thoroughly understood. To learn how AAV interacts with host cells, we investigated AAV's interaction with adenovirus (Ad), AAV's most efficient helper virus. Coinfection with Ad and AAV results in an AAV-mediated inhibition of Ad5 gene expression and replication. The AAV replication proteins (Rep) activate and repress gene expression from AAV and heterologous transcription promoters. To investigate the role of Rep proteins in the suppression of Ad propagation, we performed chromatin immunoprecipitation analyses that demonstrated in vivo AAV Rep protein interaction with the Ad E2a gene promoter. In vitro binding of purified AAV Rep68 protein to the Ad E2a promoter was characterized by electrophoretic mobility shift assays (Kd = 200 ± 25 nM). A 38 bp, Rep68-protected region (5′-TAAGAGTCAGCGCGCAGTATTTACTGAAGAGAGCCT-3′) was identified by DNase I footprint analysis. The 38-bp protected region contains the weak E2a TATA box, sequence elements that resemble the Rep binding sites identified by random sequence oligonucleotide selection, and the transcription start site. These results suggest that Rep binding to the E2a promoter contributes to the inhibition of E2a gene expression from the Ad E2a promoter and may affect Ad replication.

scholarly journals Orphan Nuclear Receptor ERRγ Is a Novel Transcriptional Regulator of IL-6 Mediated Hepatic BMP6 Gene Expression in Mice

2020 ◽  
Vol 21 (19) ◽  
pp. 7148
Author(s):  
Kamalakannan Radhakrishnan ◽  
Yong-Hoon Kim ◽  
Yoon Seok Jung ◽  
Jina Kim ◽  
Don-Kyu Kim ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcriptional Regulation ◽  
Molecular Mechanism ◽  
Nuclear Receptor ◽  
Iron Homeostasis ◽  
Luciferase Reporter ◽  
Orphan Nuclear Receptor ◽  
Knock Out

Bone morphogenetic protein 6 (BMP6) is a multifunctional growth factor involved in organ development and homeostasis. BMP6 controls expression of the liver hormone, hepcidin, and thereby plays a crucial role in regulating iron homeostasis. BMP6 gene transcriptional regulation in liver is largely unknown, but would be of great help to externally modulate iron load in pathologic conditions. Here, we describe a detailed molecular mechanism of hepatic BMP6 gene expression by an orphan nuclear receptor, estrogen-related receptor γ (ERRγ), in response to the pro-inflammatory cytokine interleukin 6 (IL-6). Recombinant IL-6 treatment increases hepatic ERRγ and BMP6 expression. Overexpression of ERRγ is sufficient to increase BMP6 gene expression in hepatocytes, suggesting that IL-6 is upstream of ERRγ. In line, knock-down of ERRγ in cell lines or a hepatocyte specific knock-out of ERRγ in mice significantly decreases IL-6 mediated BMP6 expression. Promoter studies show that ERRγ directly binds to the ERR response element (ERRE) in the mouse BMP6 gene promoter and positively regulates BMP6 gene transcription in IL-6 treatment conditions, which is further confirmed by ERRE mutated mBMP6-luciferase reporter assays. Finally, an inverse agonist of ERRγ, GSK5182, markedly inhibits IL-6 induced hepatic BMP6 expression in vitro and in vivo. Taken together, these results reveal a novel molecular mechanism on ERRγ mediated transcriptional regulation of hepatic BMP6 gene expression in response to IL-6.

Identification and Characterization of a Human Platelet Glycoprotein VI Peptidomimetic Permitting Molecular Imaging of Fibrosis.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1830-1830
Author(s):  
Martine Jandrot-Perrus ◽  
Julien Muzard ◽  
Laure Sarda-Mantel ◽  
Stéphane Loyau ◽  
Alain Meulemans ◽  
...  
Keyword(s):  
Binding Site ◽  
Cyclic Peptide ◽  
Solid Phase ◽  
Large Field ◽  
Platelet Glycoprotein ◽  
Type I ◽  
Collagen Binding ◽  
Glycoprotein Vi

Abstract Glycoprotein VI (GPVI), the main receptor for platelet activation by collagen, has been shown to play an important role in thrombosis, vascular remodelling and atherothrombosis. GPVI which belongs to the immunoglobulin receptor family, binds to fibrillar type I and type III collagens of vascular as well as non-vascular origin. 9O12.2, a high affinity monoclonal antibody directed to the GPVI extracellular domain, blocks GPVI binding to collagen and possess antithrombotic properties (Ohlmann et al J.Thromb. Haemost. 2008,6:1013). We have hypothesized that the 9O12.2 epitope overlaps, at least in part, with the collagen-binding site on GPVI and (ii) that molecules mimicking the 9O12.2 epitope can be expected to be antithrombotic by competing with platelet GPVI for binding to collagen and/or to act as tracers for collagen in vivo. A bacterial random 12 mer cyclic peptide library was screened against the 9O12.2 IgG. Twenty clones were selected. Sequencing the inserts revealed 9 peptidic motifs with 7 identical residues. One sequence was selected to synthesize a biotin-coupled constrained peptide. (designated collagelin). Surface plasmon resonance (SPR) analysis showed that 9O12.2 IgG bound to immobilized collagelin (KD 10−6M) and that binding was inhibited in the presence of soluble recombinant (sr)GPVI or after disulfide bridge reduction as expected for a molecule mimicking the 9O12.2 epitope known to be conformational (Lecut et al. J.Biol.Chem.2004, 279:52293). Using SPR and solid phase assays, we observed that collagelin bound to immobilized fibrillar collagen (KD10−7M) and that binding was inhibited by 9O12.2 IgG and by rsGPVI, indicating that collagelin mimics at least in part the collagen-binding site of GPVI. Collagelin did not inhibit collagen-induced platelet aggregation in vitro. However, histochemical analysis demonstrated that it bound to collagen on sections of rat aortas and of rat tail tendon. We then hypothesized that collagelin could be retained in vivo at sites of collagen accumulation, thus allowing isotopic imaging of fibrosis. Collagelin and a control peptide (same size and cyclic,) were labeled either indirectly using 99mTc-streptavidin or directly with 99mTc and iv injected into rats presenting fibrotic scars of myocardial infarction. Radiolabeled collagelin uptake in fibrosis areas was demonstrated in vivo by planar and tomographic scintigraphy. Mean heart-to-lung ratios were of 2.76±0.36 and 2.08±0.17 for 99m Tc-streptavidin-coupled collagelin and 99m Tc-collagelin respectively. Ex vivo, autoradiography on frozen heart sections showed a clear uptake of labeled-collagelin in the infarct collagen-rich scars with mean scar to remote myocardium activity ratios of 2.52±0.2 and 2.92±.053 for 99mTc-streptavidin-coupled collagelin and 99mTc-collagelin respectively as compared with 1.82±0.32 and 1.61±0.23 for the control peptides (p<0.006 and 0.01). In conclusion, we have produced a peptide which partly mimics the collagen binding site of GPVI, specifically binds to collagen and appears to be a specific tool for direct targeting of collagen in vitro and in vivo. Collagelin or derived molecules thus potentially have a large field of applications, as a tracer of fibrotic lesions, in non-invasive vascular as vascular pathologies.

scholarly journals Tissue specificity of type I collagen gene expression is determined at both transcriptional and post-transcriptional levels.

1984 ◽  
Vol 4 (9) ◽  
pp. 1843-1852 ◽  
Author(s):  
R J Focht ◽  
S L Adams
Keyword(s):  
Gene Expression ◽  
Rna Structure ◽  
Type I Collagen ◽  
Translational Efficiency ◽  
Type I ◽  
Collagen Gene ◽  
Differentiated Cells ◽  
Collagen Gene Expression

We analyzed the control of type I collagen synthesis in four kinds of differentiated cells from chicken embryos which synthesize very different amounts of the protein. Tendon, skin, and smooth muscle cells were found to have identical amounts of type I collagen RNAs; however, the RNAs had inherently different translatabilities, which were observed both in vivo and in vitro. Chondrocytes also had substantial amounts of type I collagen RNAs, even though they directed no detectable synthesis of the protein either in vivo or in vitro. Type I collagen RNAs in chondrocytes display altered electrophoretic mobilities, suggesting that in these cells the reduction in translational efficiency may be mediated in part by changes in the RNA structure. These data indicate that control of type I collagen gene expression is a complex process which is exerted at both transcriptional and post-transcriptional levels.

scholarly journals Temporal microRNA expression during in vitro myogenic progenitor cell proliferation and differentiation: regulation of proliferation by miR-682

2011 ◽  
Vol 43 (10) ◽  
pp. 621-630 ◽  
Author(s):  
Yongxin Chen ◽  
Jonathan Gelfond ◽  
Linda M. McManus ◽  
Paula K. Shireman
Keyword(s):  
Gene Expression ◽  
Mirna Expression ◽  
Muscle Regeneration ◽  
Progenitor Cell ◽  
Time Course ◽  
Differentially Expressed ◽  
Proliferation And Differentiation ◽  
Myogenic Progenitor

MicroRNAs (miRNAs) regulate gene expression by repressing target genes at the posttranscriptional level. Since miRNAs have unique expression profiles in different tissues, they provide pivotal regulation of many biological processes. The present study defined miRNA expression during murine myogenic progenitor cell (MPC) proliferation and differentiation to identify miRNAs involved in muscle regeneration. Muscle-related gene expression analyses revealed that the time course and expression of myosin heavy chain (MHC) and transcription factors (Myf5, MyoD, myogenin, and Pax7) were similar during in vitro MPC proliferation/differentiation and in vivo muscle regeneration. Comprehensive profiling revealed that 139 or 16 miRNAs were significantly changed more than twofold [false discovery rate (FDR) < 0.05] during MPC differentiation or proliferation, respectively; cluster analyses revealed five distinct patterns of miRNA expression during the time course of MPC differentiation. Not unexpectedly, the largest miRNA changes occurred in muscle-specific miRNAs (miR-1, -133a, and -499), which were upregulated >10-fold during MPC differentiation (FDR < 0.01). However, several previously unreported miRNAs were differentially expressed, including miR-10b, -335-3p, and -682. Interestingly, the temporal patterns of miR-1, -499, and -682 expression during in vitro MPC proliferation/differentiation were remarkably similar to those observed during in vivo muscle regeneration. Moreover, in vitro inhibition of miR-682, the only miRNA upregulated in proliferating compared with quiescent MPC, led to decreased MPC proliferation, further validating our in vitro assay system for the identification of miRNAs involved in muscle regeneration. Thus the differentially expressed miRNAs identified in the present study could represent new regulatory elements in MPC proliferation and differentiation.

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