scholarly journals Rab1b overexpression modifies Golgi size and gene expression in HeLa cells and modulates the thyrotrophin response in thyroid cells in culture

2013 ◽  
Vol 24 (5) ◽  
pp. 617-632 ◽  
Author(s):  
Nahuel Romero ◽  
Catherine I. Dumur ◽  
Hernán Martinez ◽  
Iris A. García ◽  
Pablo Monetta ◽  
...  
Keyword(s):  
Gene Expression ◽  
Hela Cells ◽  
Membrane Trafficking ◽  
Mitogen Activated Protein Kinase ◽  
Thyroid Cell ◽  
Transcriptional Level ◽  
Rab Gtpase ◽  
Mrna Levels ◽  
Consensus Binding Site ◽  
Thyroid Cells

Rab1b belongs to the Rab-GTPase family that regulates membrane trafficking and signal transduction systems able to control diverse cellular activities, including gene expression. Rab1b is essential for endoplasmic reticulum–Golgi transport. Although it is ubiquitously expressed, its mRNA levels vary among different tissues. This work aims to characterize the role of the high Rab1b levels detected in some secretory tissues. We report that, in HeLa cells, an increase in Rab1b levels induces changes in Golgi size and gene expression. Significantly, analyses applied to selected genes, KDELR3, GM130 (involved in membrane transport), and the proto-oncogene JUN, indicate that the Rab1b increase acts as a molecular switch to control the expression of these genes at the transcriptional level, resulting in changes at the protein level. These Rab1b-dependent changes require the activity of p38 mitogen-activated protein kinase and the cAMP-responsive element-binding protein consensus binding site in those target promoter regions. Moreover, our results reveal that, in a secretory thyroid cell line (FRTL5), Rab1b expression increases in response to thyroid-stimulating hormone (TSH). Additionally, changes in Rab1b expression in FRTL5 cells modify the specific TSH response. Our results show, for the first time, that changes in Rab1b levels modulate gene transcription and strongly suggest that a Rab1b increase is required to elicit a secretory response.

scholarly journals Hormonal control of the transcription factor Pax8 and its role in the regulation of thyroglobulin gene expression in thyroid cells

2002 ◽  
Vol 172 (1) ◽  
pp. 163-176 ◽  
Author(s):  
A Mascia ◽  
L Nitsch ◽  
R Di Lauro ◽  
M Zannini
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
De Novo ◽  
Hormonal Control ◽  
Thyroid Cell ◽  
Transcriptional Level ◽  
Thyroid Cells ◽  
Tsh Regulation ◽  
Pax8 Expression ◽  
Rat Thyroid

The transcription factor Pax8 plays an important role in the expression of the differentiated phenotype of thyroid follicular cells. It has recently been shown that Pax8 is necessary for thyroglobulin (Tg) gene expression in the fully differentiated rat thyroid cell line PC. We have used the PC model system to investigate the role of Pax8 as a mediator of TSH regulation of Tg gene expression. We have demonstrated that Pax8 expression, as well as Tg expression, is severely reduced in cells grown in the absence of hormones and serum. The re-addition of TSH or forskolin to the culture medium is able to restore to wild-type levels the expression of both Pax8 and Tg. We have determined that the action of TSH/forskolin on Pax8 is at the transcriptional level. However, the re-expression of Pax8 can be observed several hours before that of Tg, suggesting that either another factor is needed or that Pax8 itself must be post-translationally modified by a newly synthesized protein to become active. To distinguish between these two possibilities we have stably transfected into PC cells an exogenous Pax8 that is expressed independently of TSH. Our results indicate that in these cells the Tg promoter is still dependent on TSH despite the constitutive presence of Pax8. Furthermore, we also show that in this condition Tg gene transcription requires de novo protein synthesis. In conclusion, TSH regulates the expression of Pax8 at a transcriptional level and also regulates the activity of Pax8 by controlling the expression of one or more as yet unknown factors.

scholarly journals Bacterial Lipopolysaccharide Stimulates the Thyrotropin-Dependent Thyroglobulin Gene Expression at the Transcriptional Level by Involving the Transcription Factors Thyroid Transcription Factor-1 and Paired Box Domain Transcription Factor 8

Endocrinology ◽  
2006 ◽  
Vol 147 (7) ◽  
pp. 3260-3275 ◽  
Author(s):  
María L. Vélez ◽  
Eugenia Costamagna ◽  
Edna T. Kimura ◽  
Laura Fozzatti ◽  
Claudia G. Pellizas ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Tandem Repeats ◽  
Bacterial Lipopolysaccharide ◽  
Thyroid Cell ◽  
Transcriptional Level ◽  
Thyroid Cells ◽  
Thyroid Transcription Factor ◽  
Thyroid Autoantigens ◽  
Rat Thyroid

The bacterial lipopolysaccharide (LPS) is a biological activator that induces expression of multiple genes in several cell types. LPS has been proposed as an etiopathogenic agent in autoimmune diseases. However, whether LPS affects the expression of autoantigens has not been explored. Thyroglobulin (TG) is a key protein in thyroid hormonogenesis and one of the major thyroid autoantigens. This study aimed to analyze the action of LPS on TG gene expression in Fisher rat thyroid cell line FRTL-5 thyroid cells. We demonstrate that LPS increases the TSH-induced TG protein and mRNA level. Evidence that the effect of LPS is exerted at the transcriptional level was obtained by transfecting the minimal TG promoter. The C element of the TG promoter, which contains sequences for paired box domain transcription factor 8 (Pax8) and thyroid transcription factor (TTF)-1 binding, is essential for full TG promoter expression under TSH stimulation. The transcriptional activity of a construct containing five tandem repeats of the C site is increased by LPS, indicating a possible involvement of the C site in the LPS-induced TG gene transcription. We demonstrate that the TG promoter mutated at the Pax8 or TTF-1 binding element in the C site does not respond to LPS. In band shift assays, binding of Pax8 and TTF-1 to the C site is increased by LPS. The Pax8 and TTF-1 mRNA and protein levels are augmented by LPS. The half-lives of TG, Pax8, and TTF-1 are increased in endotoxin-treated cells. Our results reveal the ability of LPS to stimulate the expression of TG, a finding of potential pathophysiological implication.

scholarly journals Modulation of ACE-2 mRNA by inflammatory cytokines in human thyroid cells: a pilot study

Endocrine ◽  
2021 ◽  
Author(s):  
Francesca Coperchini ◽  
Gianluca Ricci ◽  
Laura Croce ◽  
Marco Denegri ◽  
Rubina Ruggiero ◽  
...  
Keyword(s):  
Inflammatory Cytokines ◽  
Combination Treatment ◽  
Primary Cultures ◽  
Human Thyroid ◽  
Thyroid Cell ◽  
Mrna Levels ◽  
Thyroid Cells ◽  
Tnf Α ◽  
Ifn Γ ◽  
Pro Inflammatory Cytokines

Abstract Introduction Angiotensin-converting-enzyme-2 (ACE-2) was demonstrated to be the receptor for cellular entry of SARS-CoV-2. ACE-2 mRNA was identified in several human tissues and recently also in thyroid cells in vitro. Purpose Aim of the present study was to investigate the effect of pro-inflammatory cytokines on the ACE-2 mRNA levels in human thyroid cells in primary cultures. Methods Primary thyroid cell cultures were treated with IFN-γ and TNF-α alone or in combination for 24 h. ACE-2 mRNA levels were measured by RT-PCR. As a control, the levels of IFN-γ inducible chemokine (CXCL10) were measured in the respective cell culture supernatants. Results The mean levels of ACE-2 mRNA increased after treatment with IFN-γ and TNF-α in all the thyroid cell preparations, while the combination treatment did not consistently synergically increase ACE-2-mRNA. At difference, CXCL10 was consistently increased by IFN-γ and synergically further increased by the combination treatment with IFN-γ + TNF-α, with respect to IFN-γ alone. Conclusions The results of the present study show that IFN-γ and, to a lesser extent TNF-α consistently increase ACE-2 mRNA levels in NHT primary cultures. More interestingly, the combined stimulation (proven to be effective according to the synergic effect registered for CXCL10) produces different responses in terms of ACE-2 mRNA modulation. These results would suggest that elevated levels of pro-inflammatory cytokines could facilitate the entering of the virus in cells by further increasing ACE-2 expression and/or account for the different degree of severity of SARS-COV-2 infection. This hypothesis deserves to be confirmed by further specific studies.

scholarly journals Methylobacterium oryzae Influences Isoepoxydon Dehydrogenase Gene Expression and Patulin Production by Penicillium expansum

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1427
Author(s):  
Tiago Barros Afonso ◽  
Lúcia Chaves Simões ◽  
Nelson Lima
Keyword(s):  
Gene Expression ◽  
Distribution Systems ◽  
Water Distribution ◽  
Penicillium Expansum ◽  
Transcriptional Level ◽  
Positive Trend ◽  
Mrna Levels ◽  
Expression Levels ◽  
Production Values ◽  
Methylobacterium Oryzae

Biofilms can be considered the main source of microorganisms in drinking water distribution systems (DWDS). The ecology of a biofilm is dependent on a variety of factors, including the presence of microbial metabolites excreted by its inhabitants. This study reports the effect of the Gram-negative bacteria Methylobacterium oryzae on the idh gene expression levels and patulin production of Penicillium expansum mature biofilms. For this purpose, a RT-qPCR method to quantify idh mRNA levels was applied. In addition, the idh expression levels were compared with the patulin production. The results obtained revealed that the effect of the bacterium on pre-established P. expansum biofilms is dependent on the time of interaction. More mature P. expansum biofilms appear to be more resistant to the inhibitory effect that M. oryzae causes towards idh gene expression and patulin production. A positive trend was observed between the idh expression and patulin production values. The results indicate that M. oryzae affects patulin production by acting at the transcriptional level of the idh gene.

Homocysteine-responsive ATF3 gene expression in human vascular endothelial cells: activation of c-Jun NH2-terminal kinase and promoter response element

Blood ◽  
2000 ◽  
Vol 96 (6) ◽  
pp. 2140-2148 ◽  
Author(s):  
Yong Cai ◽  
Chun Zhang ◽  
Tigre Nawa ◽  
Teijiro Aso ◽  
Makiko Tanaka ◽  
...  
Keyword(s):  
Gene Expression ◽  
Endothelial Cells ◽  
Protein Kinase ◽  
Transcriptional Start Site ◽  
Dominant Negative ◽  
Mitogen Activated Protein Kinase ◽  
Transcriptional Level ◽  
Appreciable Effect ◽  
Responsive Element ◽  
Atf3 Expression

Abstract Activating transcription factor (ATF) 3 is a member of ATF/cyclic adenosine monophosphate (cAMP)–responsive element binding protein (ATF/CREB) family of transcription factors and functions as a stress-inducible transcriptional repressor. To understand the stress-induced gene regulation by homocysteine, we investigated activation of the ATF3 gene in human endothelial cells. Homocysteine caused a rapid induction of ATF3 at the transcriptional level. This induction was preceded by a rapid and sustained activation of c-Jun NH2-terminal kinase/stress-activated protein kinase (JNK/SAPK), and dominant negative mitogen-activated protein kinase kinase 4 and 7 abolished these effects. The effect of homocysteine appeared to be specific, because cysteine or homocystine had no appreciable effect, but it was mimicked by dithiothreitol and β-mercaptoethanol as well as tunicamycin. The homocysteine effect was not inhibited by an active oxygen scavenger. Deletion analysis of the 5′ flanking sequence of the ATF3 gene promoter revealed that one of the major elements responsible for the induction by homocysteine is an ATF/cAMP responsive element (CRE) located at −92 to −85 relative to the transcriptional start site. Gel shift, immunoprecipitation, and cotransfection assays demonstrated that a complex (or complexes) containing ATF2, c-Jun, and ATF3 increased binding to the ATF/CRE site in the homocysteine-treated cells and activated the ATF3 gene expression, while ATF3 appeared to repress its own promoter. These data together suggested a novel pathway by which homocysteine causes the activation of JNK/SAPK and subsequent ATF3 expression through its reductive stress. Activation of JNK/SAPK and ATF3 expression in response to homocysteine may have a functional role in homocysteinemia-associated endothelial dysfunction.

scholarly journals Placental Expression of Bile Acid Transporters in Intrahepatic Cholestasis of Pregnancy

2021 ◽  
Vol 22 (19) ◽  
pp. 10434
Author(s):  
Edgar Ontsouka ◽  
Alessandra Epstein ◽  
Sampada Kallol ◽  
Jonas Zaugg ◽  
Marc Baumann ◽  
...  
Keyword(s):  
Gene Expression ◽  
Intrahepatic Cholestasis ◽  
Gene Expression Pattern ◽  
Transport Systems ◽  
Transcriptional Level ◽  
Maternal Body Mass Index ◽  
Mrna Levels ◽  
Intrahepatic Cholestasis Of Pregnancy ◽  
Related Condition ◽  
Cholestasis Of Pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-related condition characterized by increased maternal circulating bile acids (BAs) having adverse fetal effects. We investigated whether the human placenta expresses specific regulation patterns to prevent fetal exposition to harmful amounts of BAs during ICP. Using real-time quantitative PCR, we screened placentae from healthy pregnancies (n = 12) and corresponding trophoblast cells (n = 3) for the expression of 21 solute carriers and ATP-binding cassette transporter proteins, all acknowledged as BA- and/or cholestasis-related genes. The placental gene expression pattern was compared between healthy women and ICP patients (n = 12 each). Placental SLCO3A1 (OATP3A1) gene expression was significantly altered in ICP compared with controls. The other 20 genes, including SLC10A2 (ASBT) and EPHX1 (EPOX, mEH) reported for the first time in trophoblasts, were comparably abundant in healthy and ICP placentae. ABCG5 was undetectable in all placentae. Placental SLC10A2 (ASBT), SLCO4A1 (OATP4A1), and ABCC2 mRNA levels were positively correlated with BA concentrations in ICP. Placental SLC10A2 (ASBT) mRNA was also correlated with maternal body mass index. We conclude that at the transcriptional level only a limited response of BA transport systems is found under ICP conditions. However, the extent of the transcriptional response may also depend on the severity of the ICP condition and the magnitude by which the maternal BA levels are increased.

scholarly journals The Flavonoid Quercetin Induces AP-1 Activation in FRTL-5 Thyroid Cells

Antioxidants ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 112 ◽  
Author(s):  
Cesidio Giuliani
Keyword(s):  
Binding Site ◽  
Thyroid Function ◽  
Thyroid Cell ◽  
Consensus Binding Site ◽  
Thyroid Cells ◽  
Basal Activity ◽  
Reporter Vector ◽  
Rat Thyroid

Previous studies have shown that quercetin inhibits thyroid function both in vitro and in vivo. An attempt to evaluate the effect of quercetin at the promoter level of the thyroid-specific genes led to the observation that this compound induces the basal activity of the reporter vector. Therefore, the action of quercetin has been evaluated on the basal activity of several reporter vectors: The PGL3 basic, promoter and control vectors from Promega, and a pSV-based chloramphenicol acetyltransferase (CAT) reporter vector. In the Fisher Rat Thyroid cell Line FRTL-5 thyroid cells transiently transfected, quercetin 10 μM increased the basal activity of all the reporter vectors evaluated, although the degree of the effect was significantly different among them. The analysis of the difference among the regulatory regions of these vectors identified the activator protein 1 (AP-1) binding site as one of the potential sites involved in the quercetin effect. Electromobility shift assay experiments showed that the treatment with quercetin induced the binding of a protein complex to an oligonucleotide containing the AP-1 consensus binding site. This is the first study showing an effect of quercetin on AP-1 activity in thyroid cells. Further studies are in progress to understand the role of AP-1 activation in the effects of quercetin on thyroid function.

Signal transduction events involved in TPA downregulation of SP-A gene expression

2004 ◽  
Vol 286 (6) ◽  
pp. L1210-L1219 ◽  
Author(s):  
Olga L. Miakotina ◽  
Jeanne M. Snyder
Keyword(s):  
Gene Expression ◽  
Protein Kinase ◽  
Mapk Pathway ◽  
Surfactant Protein ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Inhibitory Effects ◽  
Novel Isoforms

Surfactant protein A (SP-A), the most abundant pulmonary surfactant protein, plays a role in innate host defense and blocks the inhibitory effects of serum proteins on surfactant surface tension-lowering properties. SP-A mRNA and protein are downregulated by phorbol esters (TPA) via inhibition of gene transcription. We evaluated the TPA signaling pathways involved in SP-A inhibition in a lung cell line, H441 cells. TPA caused sustained phosphorylation of p44/42 mitogen-activated protein kinase (MAPK), p38 MAPK, and c-Jun-NH2-terminal kinase. An inhibitor of conventional and novel isoforms of protein kinase C (PKC) and two inhibitors of p44/42 MAPK kinase partially or completely blocked the inhibitory effects of TPA on SP-A mRNA levels. In contrast, inhibitors of conventional PKC-α and -β, stress-activated protein kinases, protein phosphatases, protein kinase A, and the phosphatidylinositol 3-kinase pathway had no effect on the TPA-mediated inhibition of SP-A mRNA. TPA also stimulated the synthesis of c-Jun mRNA and protein in a time-dependent manner. Inhibitors of the p44/42 MAPK signaling pathway and PKC blocked the TPA-mediated phosphorylation of p44/42 MAPK and the increase in c-Jun mRNA. We conclude that TPA inhibits SP-A gene expression via novel isoforms of PKC, the p44/42 MAPK pathway, and the activator protein-1 complex.

Control of the expression of inflammatory response genes

2003 ◽  
Vol 70 ◽  
pp. 95-106 ◽  
Author(s):  
Jeremy Saklatvala ◽  
Jonathan Dean ◽  
Andrew Clark
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Inflammatory Response ◽  
Mapk Pathway ◽  
Interleukin 1 ◽  
Mitogen Activated Protein Kinase ◽  
Mrna Levels ◽  
Matrix Metalloproteinase 1 ◽  
Inflammatory Stimuli ◽  
Mitogen Activated Protein

The expression of genes involved in the inflammatory response is controlled both transcriptionally and post-transcriptionally. Primary inflammatory stimuli, such as microbial products and the cytokines interleukin-1 (IL-1) and tumour necrosis factor α (TNFα), act through receptors of either the Toll and IL-1 receptor (TIR) family or the TNF receptor family. These cause changes in gene expression by activating four major intracellular signalling pathways that are cascades of protein kinases: namely the three mitogen-activated protein kinase (MAPK) pathways, and the pathway leading to activation of the transcription factor nuclear factor ϰB (NFϰB). The pathways directly activate and induce the expression of a limited set of transcription factors which promote the transcription of inflammatory response genes. Many of the mRNAs are unstable, and are stabilized by the p38 MAPK pathway. Instability is mediated by clusters of the AUUUA motif in the 3″ untranslated regions of the mRNAs. Control of mRNA stability provides a means of increasing the amplitude of a response and allows rapid adjustment of mRNA levels. Not all mRNAs stabilized by p38 contain AUUUA clusters; for example, matrix metalloproteinase-1 and -3 mRNAs lack these clusters, but are stabilized. Inflammatory gene expression is inhibited by glucocorticoids. These suppress MAPK signalling by inducing a MAPK phosphatase. This may be a significant mechanism additional to that by which the glucocorticoid receptor interferes with transcription factors.

Murine retroviruses control class I major histocompatibility antigen gene expression via a trans effect at the transcriptional level

1987 ◽  
Vol 7 (7) ◽  
pp. 2406-2415
Author(s):  
L D Wilson ◽  
D C Flyer ◽  
D V Faller
Keyword(s):  
Gene Expression ◽  
Class I ◽  
Transcriptional Level ◽  
Immune Recognition ◽  
Mrna Levels ◽  
Major Histocompatibility ◽  
Class I Mhc ◽  
Mhc Genes ◽  
Beta 2 ◽  
Beta 2 Microglobulin

Moloney murine leukemia virus (M-MuLV) and Moloney murine sarcoma virus (M-MSV) exert a regulatory effect on the class I genes of the murine major histocompatibility complex (MHC). We have previously shown that M-MuLV infection of mouse fibroblasts results in a substantial increase in cell surface expression of H-2K, H-2D, and H-2L proteins, whereas M-MSV, upon coinfection of the same cells, is apparently able to override the MuLV-induced increase in H-2 expression. As a result of this modulation, immune recognition of the infected cells is profoundly altered. Our efforts have been directed toward elucidating the molecular basis for this phenomenon. We report here that stimulation of interferon production as a result of infection with MuLV does not occur and, therefore, is not the cause of MuLV-induced enhancement of MHC expression. Control of H-2 class I and beta 2-microglobulin gene expression by M-MuLV, and probably by M-MSV, takes place at the transcriptional level as indicated by nuclear runoff studies and analysis of steady-state mRNA levels. Our demonstration that M-MuLV controls expression of widely separated endogenous cellular genes (those coding for H-2D, H-2K, H-2L, and beta 2-microglobulin), transfected class I MHC genes, and unintegrated chimeric genes consisting of fragments of class I MHC genes linked to sequences encoding a procaryotic enzyme, chloramphenicol acetyltransferase, suggests that M-MuLV exerts its effect in trans and not by proviral integration in the vicinity of the H-2 gene complex. Finally, we show that the sequences of at least one MHC gene, which are responsive to trans regulation by M-MuLV, lie within 1.2 kilobases upstream of the initiation codon for that gene.

Sign in / Sign up

Export Citation Format

Share Document