scholarly journals A novel function of Tis11b/BRF1 as a regulator of Dll4 mRNA 3′-end processing

2011 ◽  
Vol 22 (19) ◽  
pp. 3625-3633 ◽  
Author(s):  
Agnès Desroches-Castan ◽  
Nadia Cherradi ◽  
Jean-Jacques Feige ◽  
Delphine Ciais

Tis11b/BRF1 belongs to the tristetraprolin family, the members of which are involved in AU-rich-dependent regulation of mRNA stability/degradation. Mouse inactivation of the Tis11b gene has revealed disorganization of the vascular network and up-regulation of the proangiogenic factor VEGF. However, the VEGF deregulation alone cannot explain the phenotype of Tis11b knockouts. Therefore we investigated the role of Tis11b in expression of Dll4, another angiogenic gene for which haploinsufficiency is lethal. In this paper, we show that Tis11b silencing in endothelial cells leads to up-regulation of Dll4 protein and mRNA expressions, indicating that Dll4 is a physiological target of Tis11b. Tis11b protein binds to endogenous Dll4 mRNA, and represses mRNA expression without affecting its stability. In the Dll4 mRNA 3′ untranslated region, we identified one particular AUUUA motif embedded in a weak noncanonical polyadenylation (poly(A)) signal as the major Tis11b-binding site. Moreover, we observed that inhibition of Tis11b expression changes the ratio between mRNAs that are cleaved or read through at the poly(A) signal position, suggesting that Tis11b can interfere with mRNA cleavage and poly(A) efficiency. Last, we report that this Tis11b-mediated mechanism is used by endothelial cells under hypoxia for controlling Dll4 mRNA levels. This work constitutes the first description of a new function for Tis11b in mammalian cell mRNA 3′-end maturation.

1995 ◽  
Vol 129 (6) ◽  
pp. 1651-1657 ◽  
Author(s):  
Y Geng ◽  
M Lotz

This study addresses the role of intracellular calcium (Ca2+) in the expression of iNOS, an IL-1 inducible gene in human articular chondrocytes. The calcium ionophore A23187 and ionomycin did not induce NO release or iNOS expression but inhibited dose dependently IL-1-induced NO release with IC50 of 200 nM and 100 nM, respectively. Increased intracellular Ca2+ induced by thapsigargin or cyclopiazonic acid, inhibitors of the endoplasmic reticulum Ca2+ ATPase, had similar inhibitory effects with IC50 of 1 nM and 3 microM, respectively. LPS and TNF alpha induced NO production were also suppressed by these Ca2+ elevating drugs. Levels of IL-1-induced iNOS protein were reduced by A23187, thapsigargin, and cyclopiazonic acid. These drugs as well as Bay K 8644 and KCl inhibited IL-1-induced iNOS mRNA expression. To analyze the role of Ca2+ in the expression of other IL-1 responsive genes in chondrocytes, these Ca2+ modulating drugs were tested for effects on COXII. In contrast to the inhibitory effects on iNOS mRNA, these drugs induced COXII mRNA expression and in combination with IL-1, enhanced COXII mRNA levels. Ca2+ mediated increases in COXII mRNA expression were associated with an increase in COXII protein. The kinetics of Ca2+ effects on IL-1-induced iNOS mRNA levels suggested a posttranscriptional mechanism. Analysis of iNOS mRNA half life showed that it was 6-7 h in IL-1-stimulated cells and decreased by A23187 to 2-3 h. In conclusion, these results show that Ca2+ inhibits IL-1-induced NO release, iNOS protein, and mRNA expression in human articular chondrocytes by reducing iNOS mRNA stability. Under identical conditions increased Ca2+ enhances IL-1-induced COXII gene and protein expression.


2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Kayoko Miyata ◽  
Ryousuke Satou ◽  
L Gabriel Navar

Introduction: We have demonstrated that Ang II augments angiotensinogen (AGT) expression in rat preglomerular vascular smooth muscle cells (VSMCs). However, it is unclear if endothelial cells (ECs) are involved in augmentation of AGT in renal afferent arterioles. Hypothesis: We assessed the hypothesis that the ECs respond to paracrine signals that Ang II contribute to AGT augmentation in VSMCs. Objective: We established primary cultures of preglomerular ECs and examined the effects of Ang II and/or culture medium from ECs on AGT expression in preglomerular VSMCs. Methods and Results: We established primary cultures of preglomerular ECs, isolated from afferent arterioles of Sprague-Dawley rats. The cells were identified as ECs by being positive for a marker, CD34 and endothelial NOS and negative for alpha-SMA (a marker for VSMCs) and P4H-b (a marker for Fibroblasts) by immnostaining. The expression levels of AGT mRNA and renin mRNA in preglomerular ECs were examined by real-time RT-PCR. Ang II (100 pmol/L) increased AGT mRNA levels (1.34 +/- 0.16, by 100 pmol/L, N=4) and Renin mRNA levels (6.16 +/- 0.96, by 100 nmol/L, N=4) in ECs. On the other hand, the same dose of Ang II suppressed Renin mRNA expression in isolated Juxtaglomerular cells (JGs). These results indicate that preglomerular ECs are respond to Ang II and exclude the possible contamination of JGs into ECs. 100 pmol/L of Ang II increased AGT mRNA expression levels (1.37 +/- 0.03, relative ratio, N=4) in preglomerular VSMCs and the culture medium of ECs without Ang II treatment also more increased AGT mRNA expression (1.62 +/- 0.13, relative ratio, N=4) in preglomerular VSMCs. The AGT mRNA expression augmentation was enhanced when preglomerular VSMCs were treated with culture medium of Ang II-treated preglomerular ECs (2.39 +/- 0.41, relative ratio, N=4). The synergistic effects of Ang II and preglomerular ECs were also observed in PAI-1 expression in preglomerular VSMCs. Conclusion: These data demonstrate that preglomerular ECs contribute to Ang II-upregulation of AGT in renal afferent arterioles leading to further Ang II augmentation, which leads to increases in inflammatory and sclerotic factors in preglomerular VSMCs.


Epigenomics ◽  
2021 ◽  
Author(s):  
Beatriz Garcia-Ruiz ◽  
Manuel Castro de Moura ◽  
Gerard Muntané ◽  
Lourdes Martorell ◽  
Elena Bosch ◽  
...  

Aim: To investigate DDR1 methylation in the brains of bipolar disorder (BD) patients and its association with DDR1 mRNA levels and comethylation with myelin genes. Materials & methods: Genome-wide profiling of DNA methylation (Infinium MethylationEPIC BeadChip) corrected for glial composition and DDR1 gene expression analysis in the occipital cortices of individuals with BD (n = 15) and healthy controls (n = 15) were conducted. Results: DDR1 5-methylcytosine levels were increased and directly associated with DDR1b mRNA expression in the brains of BD patients. We also observed that DDR1 was comethylated with a group of myelin genes. Conclusion: DDR1 is hypermethylated in BD brain tissue and is associated with isoform expression. Additionally, DDR1 comethylation with myelin genes supports the role of this receptor in myelination.


1998 ◽  
Vol 79 (01) ◽  
pp. 217-221 ◽  
Author(s):  
Koichi Kokame ◽  
Toshiyuki Miyata ◽  
Naoaki Sato ◽  
Hisao Kato

SummaryThrombotic complications are frequently associated with atherosclerosis. Lysophosphatidylcholine (LPC), a component accumulated in oxidatively modified LDL (ox-LDL), is known to play a crucial role in the initiation and progression of atherosclerotic vascular lesions. Since a vascular anticoagulant, tissue factor pathway inhibitor (TFPI), has the function of regulating the initial reaction of tissue factor (TF)-induced coagulation, we investigated the effect of LPC on TFPI synthesis in cultured human umbilical vein endothelial cells (HUVEC). The treatment of HUVEC with LPC for 24 h decreased TFPI antigen levels in both the culture medium and the cell lysate in a dose-dependent manner. Northern blot analysis revealed that LPC caused a time-dependent decrease in the TFPI mRNA levels. The levels of TFPI antigen and mRNA were decreased to 72% and 38%, respectively, by the incubation with 50 μM LPC for 24 h. The down-regulation by LPC of TFPI mRNA expression was not observed in the presence of cycloheximide, suggesting that protein synthesis was involved in the suppression of TFPI mRNA expression. The TFPI mRNA levels in actinomycin D-treated cells were relatively stable, indicating that the down-regulation of TFPI mRNA by LPC would be partly explained by the enhanced mRNA destabilization. In contrast to the significant down-regulatory effects of LPC on TFPI expression, LPC did not induce TF mRNA expression in HUVEC. These results indicate that LPC accumulated in the atherosclerotic vascular wall would suppress endothelial TFPI synthesis, reducing the antithrombotic property of endothelial cells.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Franca Marino ◽  
Luigina Guasti ◽  
Matteo Tozzi ◽  
Laura Schembri ◽  
Luana Castiglioni ◽  
...  

Atherosclerosis is an inflammatory disease characterized by immunological activity, in which endothelial dysfunction represents an early event leading to subsequent inflammatory vascular damage. We investigated gene expression of the adhesion molecules (AMs) ICAM-1, VCAM-1, andβ1-integrin in endothelial cells (ECs) isolated from venous blood (circulating EC, cEC) and purified from femoral plaques (pEC) obtained from 9 patients with peripheral artery disease (PAD) submitted to femoral artery thrombendarterectomy (FEA). In addition, in peripheral blood mononuclear cells (PBMCs) of the same subjects, we investigated gene expression of IFN-γ, IL-4, TGF-β, and IL-10. Patients were longitudinally evaluated 1 month before surgery, when statin treatment was established, at the time of surgery, and after 2 and 5 months. All AM mRNA levels, measured by means of real-time PCR, in cEC diminished during the study, up to 41–50% of initial levels at followup. AM mRNA expression was significantly higher in pEC than in cEC. During the study, in PBMCs, TGF-βand IL-10 mRNA levels remained unchanged while IFN-γand IL-4 levels increased; however, the ratio IFN-γ/IL-4 showed no significant modification. In PAD patients, FEA and statin treatment induce a profound reduction of AM expression in cEC and affect cytokine mRNA expression in PBMCs.


2017 ◽  
Vol 44 (8) ◽  
pp. 1198-1205 ◽  
Author(s):  
Takashi Taniguchi ◽  
Yoshihide Asano ◽  
Kouki Nakamura ◽  
Takashi Yamashita ◽  
Ryosuke Saigusa ◽  
...  

Objective.CXCL6, a chemokine with proangiogenic property, is reported to be involved in vasculopathy associated with systemic sclerosis (SSc). We investigated the contribution of CXCL6 to SSc development by focusing on the association of friend leukemia virus integration 1 (Fli1) deficiency, a potential predisposing factor of SSc, with CXCL6 expression and clinical correlation of serum CXCL6 levels.Methods.mRNA levels of target genes and the binding of Fli1 to the CXCL6 promoter were evaluated by quantitative reverse transcription-PCR and chromatin immunoprecipitation, respectively. Serum CXCL6 levels were determined by ELISA.Results.FLI1 siRNA significantly enhanced CXCL6 mRNA expression in human dermal fibroblasts and human dermal microvascular endothelial cells, while Fli1 haploinsufficiency significantly suppressed CXCL6 mRNA expression in murine peritoneal macrophages stimulated with lipopolysaccharide. Supporting a critical role of Fli1 deficiency to induce SSc-like phenotypes, CXCL6 mRNA expression was higher in SSc dermal fibroblasts than in normal dermal fibroblasts. Importantly, Fli1 bound to the CXCL6 promoter in dermal fibroblasts, endothelial cells, and THP-1 cells. In patients with SSc, serum CXCL6 levels correlated positively with the severity of dermal and pulmonary fibrosis and were elevated in association with cardiac and pulmonary vascular involvement and cutaneous vascular symptoms, including Raynaud phenomenon, digital ulcers (DU)/pitting scars, and telangiectasia. Especially, serum CXCL6 levels were associated with DU/pitting scars and heart involvement by multiple regression analysis.Conclusion.CXCL6 expression is upregulated by Fli1 deficiency in fibroblasts and endothelial cells, potentially contributing to the development of fibrosis and vasculopathy in the skin, lung, and heart of SSc.


2010 ◽  
Vol 104 (09) ◽  
pp. 582-591 ◽  
Author(s):  
Trine Lund ◽  
Stig Hermansen ◽  
Thomas Andreasen ◽  
Jan Olsen ◽  
Bjarne Østerud ◽  
...  

SummaryShear stress has an established effect on mature endothelial cells, but less is known about how shear stress regulates endothelial progenitor cells (EPCs). In vitro expanded EPCs isolated from adult human blood represent a novel tool in regenerative vessel therapy. However, in vitro culturing may generate cells with unfavourable properties. The aim of the present study was therefore to assess whether shear stress may influence the inflammatory and thrombotic phenotype of in vitro expanded EPCs. In late outgrowth EPCs, 6 hours of shear stress (6.0 dynes/ cm2) significantly reduced the mRNA levels of IL-8, COX2, and tissue factor (TF) compared to static controls. This was associated with a reduced TF activity. In contrast, mRNA expression of NOS3 was significantly increased following 6 and 24 hours of shear stress. In accordance with this, NOS3 protein expression was increased following 24 hours of shear stress. Overall stimulation with the proinflammatory mediator, TNFα, for the final 2 hours increased the mRNA expression of IL-6, IL-8, MCP-1, ICAM1, and TF. However exposure to 6 hours of shear stress significantly suppressed the inductory potential of TNFα to increase the mRNA levels of IL-6, IL-8, COX2, and TF. Additionally, TNFα increased TF activity approximately 10 times, an effect that was also significantly reduced by exposure to 6 and 24 hours of shear stress. The effect of shear on the gene levels of TF and NOS3 were not blocked by the NOS inhibitor L-NAME. These observations suggest that EPCs are capable of functionally responding to shear stress.


2007 ◽  
Vol 292 (4) ◽  
pp. R1649-R1656 ◽  
Author(s):  
John Yuh-Lin Yu ◽  
Chin-Hon Pon ◽  
Hui-Chen Ku ◽  
Chih-Ting Wang ◽  
Yung-Hsi Kao

Galanin is a hormone 29 or 30 amino acids (aa) long that is widely distributed within the body and exerts numerous biological effects in vertebrates. To fully understand its physiological roles in reptiles, we analyzed preprogalanin cDNA structure and expression in the turtle pituitary. Using the Chinese soft-shell turtle ( Pelodiscus sinensis order Testudines), we obtained a 672-base pair (bp) cDNA containing a 99-bp 5′-untranslated region, a 324-bp preprogalanin coding region, and a 249-bp 3′-untranslated region. The open-reading frame encoded a 108-aa preprogalanin protein with a putative 23-aa signal sequence at the NH2 terminus. Based on the location of putative Lys-Arg dibasic cleavage sites and an amidation signal of Gly-Lys-Arg, we propose that turtle preprogalanin is processed to yield a 29-aa galanin peptide with Gly1 and Thr29 substitutions and a COOH-terminal amidation. Sequence comparison revealed that turtle preprogalanin and galanin-29 had 48–81% and 76–96% aa identities with those of other vertebrates, respectively, suggesting their conservative nature. Expression of the turtle galanin gene was detected in the pituitary, brain, hypothalamus, stomach, liver, pancreas, testes, ovaries, and intestines, but not in the adipose or muscle tissues, suggesting tissue-dependent differences. An in vitro study that used pituitary tissue culture indicated that treatment with 17β-estradiol, testosterone, or gonadotropin-releasing hormone resulted in increased galanin mRNA expression with dose- or time-dependent differences, whereas leptin and neuropeptide Y reduced galanin mRNA levels. These results suggest a hormone-dependent effect on hypophyseal galanin mRNA expression.


2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 20030-20030
Author(s):  
M. B. Pinho ◽  
J. Sellos ◽  
F. Costas ◽  
D. Herchenhorn ◽  
F. A. Peixoto ◽  
...  

20030 Background: The relation between apoptosis-related molecules and chemosensitivity has been extensively studied. In recent years, attention has shifted to a new family of inhibitor of apoptosis proteins (IAPs). XIAP (X- linked inhibitor of apoptosis) is the most versatile and potent member of the IAP family. To date, the overexpression of XIAP has been detected in various cancers. XAF1 (X-linked inhibitor of apoptosis associated factor 1) is a new protein identified for its ability to interact with XIAP. Neither XIAP nor XAF1 or XIAP/XAF1 mRNA expression have been studied in bladder cancer patients. Methods: The expression of XIAP and XAF1 mRNA was analyzed by a real time quantitative fluorogenic PCR method in a group of 17 patients with locally advanced bladder cancer treated with a combination of neoadjuvant Gemcitabine and Cisplatin. The prognostic significance of XIAP and XAF1 mRNA expression and the correlation with several clinicopathological variables was evaluated. Results: XIAP and XAF1 mRNA expression was detected in all 17 (100%) case samples. The levels of XIAP mRNA expression showed a moderate variation among samples. In contrast, XAF1 and XIAP/XAF1 mRNA levels showed significant variation among samples. Bivariate correlation analyses revealed a significant positive Spearman direct correlation coefficient between the XIAP expression and the pathological response. No significant correlation was found for XAF1 expression as well as for the XIAP/XAF1 ratio and clinical and pathological response. Conclusions: This is first study to address the role of XIAP, its negative regulator XAF1, and the XIAP/XAF1 ratio in bladder cancer patients. The positive correlation between the XIAP mRNA expression and the pathological response is in line with a previous study from our group in which a correlation was found between XIAP expression and survival. All these observations point to a complex role of XIAP in tumor biology. XAF1 mRNA expression in bladder carcinomas did not achieve significance as an independent predictive and prognostic factor in a bivariate analysis. Further studies are necessary in order to better assess a possible clinical value for XIAP and XAF1 as predictive and prognostic markers in cancer patients. No significant financial relationships to disclose.


2001 ◽  
Vol 69 (3) ◽  
pp. 1420-1427 ◽  
Author(s):  
Brian K. Coombes ◽  
James B. Mahony

ABSTRACT Strong epidemiological and pathological evidence supports a role for Chlamydia pneumoniae infection in atherosclerosis and human coronary heart disease. Animal models have shown that C. pneumoniae disseminates hematogenously in infected monocytes and macrophages, while in vitro data suggest that infected macrophages can transmit C. pneumoniae infection directly to endothelial cells. Endothelial cells may be key in vivo targets for C. pneumoniae infection; given that these cells are important in regulating the dynamics of the vessel wall, we used cDNA microarrays to study the transcriptional response of endothelial cells to infection with C. pneumoniae. cDNA arrays were used to characterize the mRNA expression profiles for 268 human genes following infection with C. pneumoniae, which were compared to mRNA profiles of uninfected cells. Selected genes of interest were further investigated by reverse transcription-PCR throughout a 24-h period of infection. C. pneumoniaeinfection upregulated mRNA expression for approximately 20 (8%) of the genes studied. Genes coding for cytokines (interleukin-1), chemokines (monocyte chemotactic protein 1 and interleukin-8), and cellular growth factors (heparin-binding epidermal-like growth factor, basic fibroblast growth factor, and platelet-derived growth factor B chain) were the most prominently upregulated. In addition to these families of genes, increases in mRNA levels for intracellular kinases and cell surface receptors with signal transduction activities were observed. Time course experiments showed that mRNA levels were upregulated within 2 h following infection. These results expand our knowledge of the response of endothelial cells to C. pneumoniae by further defining the repertoire of C. pneumoniae-inducible genes and provide new insight into potential mechanisms of atherogenesis. In addition, the use of cDNA microarrays may prove useful for the study of host cell responses to C. pneumoniae infection during latent and replicative stages of infection and related pathology.


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