Costimulatory action of glycoinositolphospholipids from Trypanosoma cruzi: increased interleukin 2 secretion and induction of nuclear translocation of the nuclear factor of activated T cells 1

1999 ◽  
Vol 13 (12) ◽  
pp. 1627-1636 ◽  
Author(s):  
Maria Bellio ◽  
Ana‐Carolina S. C. Oliveira ◽  
Claudia S. Mermelstein ◽  
Marcia A. M. Capella ◽  
João P. B. Viola ◽  
...  
Keyword(s):  
T Cells ◽  
Trypanosoma Cruzi ◽  
Nuclear Translocation ◽  
Interleukin 2 ◽  
Nuclear Factor ◽  
Activated T Cells

Regulation of nuclear factor of activated T cells by phosphotyrosyl-specific phosphatase activity: a positive effect on HIV-1 long terminal repeat–driven transcription and a possible implication of SHP-1

Blood ◽  
2001 ◽  
Vol 97 (8) ◽  
pp. 2390-2400 ◽  
Author(s):  
Jean-François Fortin ◽  
Benoit Barbeau ◽  
Gilles A. Robichaud ◽  
Marie-Ève Paré ◽  
Anne-Marie Lemieux ◽  
...  
Keyword(s):  
T Cells ◽  
Long Terminal Repeat ◽  
Nuclear Translocation ◽  
Interleukin 2 ◽  
Dominant Negative ◽  
Terminal Repeat ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Nfat Activation ◽  
Hiv 1

Abstract Although protein tyrosine phosphatase (PTP) inhibitors used in combination with other stimuli can induce interleukin 2 (IL-2) production in T cells, a direct implication of nuclear factor of activated T cells (NFAT) has not yet been demonstrated. This study reports that exposure of leukemic T cells and human peripheral blood mononuclear cells to bis-peroxovanadium (bpV) PTP inhibitors markedly induce activation and nuclear translocation of NFAT. NFAT activation by bpV was inhibited by the immunosuppressive drugs FK506 and cyclosporin A, as well as by a specific peptide inhibitor of NFAT activation. Mobility shift assays showed specific induction of the NFAT1 member by bpV molecules. The bpV-mediated NFAT activation was observed to be important for the up-regulation of the human immunodeficiency virus 1 (HIV-1) long terminal repeat (LTR) and the IL-2 promoter; NFAT1 was demonstrated to be particularly important in bpV-dependent positive action on HIV-1 LTR transcription. The active participation of p56lck, ZAP-70, p21ras, and calcium in the bpV-mediated signaling cascade leading to NFAT activation was confirmed, using deficient cell lines and dominant-negative mutants. Finally, overexpression of wild-type SHP-1 resulted in a greatly diminished activation of NFAT by bpV, suggesting an involvement of SHP-1 in the regulation of NFAT activation. These data were confirmed by constitutive NFAT translocation observed in Jurkat cells stably expressing a dominant-negative version of SHP-1. The study proposes that PTP activity attenuates constitutive kinase activities that otherwise would lead to constant NFAT activation and that this activation is participating in HIV-1 LTR stimulation by PTP inhibition.

scholarly journals Integration of Calcium and Cyclic AMP Signaling Pathways by 14-3-3

2000 ◽  
Vol 20 (2) ◽  
pp. 702-712 ◽  
Author(s):  
Chi-Wing Chow ◽  
Roger J. Davis
Keyword(s):  
T Cells ◽  
Cyclic Amp ◽  
Signaling Pathways ◽  
Interleukin 2 ◽  
Camp Signaling ◽  
Phosphorylation Sites ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Transcription Activity ◽  
Kinase A

ABSTRACT Calcium-stimulated nuclear factor of activated T cells (NFAT) transcription activity at the interleukin-2 promoter is negatively regulated by cyclic AMP (cAMP). This effect of cAMP is mediated, in part, by protein kinase A phosphorylation of NFAT. The mechanism of regulation involves the creation of a phosphorylation-dependent binding site for 14-3-3. Decreased NFAT phosphorylation caused by the calcium-stimulated phosphatase calcineurin, or mutation of the PKA phosphorylation sites, disrupted 14-3-3 binding and increased NFAT transcription activity. In contrast, NFAT phosphorylation caused by cAMP increased 14-3-3 binding and reduced NFAT transcription activity. The regulated interaction between NFAT and 14-3-3 provides a mechanism for the integration of calcium and cAMP signaling pathways.

scholarly journals Requirement for Transcription Factor NFAT in Interleukin-2 Expression

1999 ◽  
Vol 19 (3) ◽  
pp. 2300-2307 ◽  
Author(s):  
Chi-Wing Chow ◽  
Mercedes Rincón ◽  
Roger J. Davis
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
Transcription Factor ◽  
Nuclear Translocation ◽  
Interleukin 2 ◽  
Inhibitory Effect ◽  
Dominant Negative ◽  
Activated T Cells ◽  
Nfat Activation ◽  
Nfat Transcription Factor

ABSTRACT The nuclear factor of activated T cells (NFAT) transcription factor is implicated in expression of the cytokine interleukin-2 (IL-2). Binding sites for NFAT are located in the IL-2 promoter. Furthermore, pharmacological studies demonstrate that the drug cyclosporin A inhibits both NFAT activation and IL-2 expression. However, targeted disruption of the NFAT1 and NFAT2 genes in mice does not cause decreased IL-2 secretion. The role of NFAT in IL-2 gene expression is therefore unclear. Here we report the construction of a dominant-negative NFAT mutant (dnNFAT) that selectively inhibits NFAT-mediated gene expression. The inhibitory effect of dnNFAT is mediated by suppression of activation-induced nuclear translocation of NFAT. Expression of dnNFAT in cultured T cells caused inhibition of IL-2 promoter activity and decreased expression of IL-2 protein. Similarly, expression of dnNFAT in transgenic mice also caused decreased IL-2 gene expression. These data demonstrate that NFAT is a critical component of the signaling pathway that regulates IL-2 expression.

Reciprocal Regulation of DSCR1 (Down Syndrome Critical Region 1) Expression and NFAT (Nuclear Factor of Activated T Cells) Activation in Megakaryocytes.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2204-2204
Author(s):  
Satu Kyttaelae ◽  
Ivonne Habermann ◽  
Martin Bornhaeuser ◽  
Gerhard Ehninger ◽  
Alexander Kiani
Keyword(s):  
T Cells ◽  
Down Syndrome ◽  
Critical Region ◽  
Fas Ligand ◽  
Nuclear Translocation ◽  
Specific Inhibitor ◽  
Chromosome 21 ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Retroviral Transduction

Abstract NFAT (Nuclear Factor of Activated T cells) is a family of calcium-induced, calcineurin-dependent transcription factors, well characterized as central regulators of inducible gene expression in T lymphocytes but now known to function also in several other cell types in various adaptation and differentiation processes. Activation of NFAT by the phosphatase calcineurin is counteracted by several inhibitory kinases and can be completely blocked by the immunosuppressant Cyclosporin A. The Down syndrome critical region 1 (DSCR1; also termed CSP1, MCIP1 or RCAN1) gene belongs to the calcipressin family of endogenous calcineurin inhibitors and is expressed in several isoforms, one of which (isoform C, coded by exons 4–7) has been described to be a transcriptional target for NFAT in striated muscle, endothelial, and neural cells. The DSCR1 gene is located within the Down syndrome critical region of human chromosome 21 and is, together with 200–300 other genes, overexpressed about 1.5-fold in patients with Down syndrome (DS). Previously, dysregulation of NFAT signaling by overexpression of DSCR1 has been implicated in causing various of the pathophysiological features observed in DS patients. Children with DS also suffer from an about 500-fold increased incidence of acute megakaryocytic leukemia; the respective roles of NFAT or DSCR1 in megakaryocytes of either normal individuals or those with DS, however, has not yet been established. Here we show that DSCR1 is upregulated during megakaryocytic differentiation in a lineage-specific manner, and in mature megakaryocytes is further strongly induced by calcineurin stimulation. DSCR1 expression in megakaryocytes is regulated by NFAT, since overexpression of NFATc2 enhances, while overexpression of the specific inhibitor of NFAT activation, VIVIT, suppresses expression of the gene. We further demonstrate that DSCR1 does not only represent an NFAT target in megakaryocytes, but itself acts an inhibitor of NFAT signaling in these cells. Overexpression of DSCR1 in CMK cells as well as in primary megakaryocytes by retroviral transduction profoundly suppressed ionomycin-induced dephosphorylation and nuclear translocation of NFATc2, as well as transactivation of an NFAT-dependent promoter construct. Finally, overexpression of DSCR1 in megakaryocytes markedly downregulated both the constitutive and induced expression of Fas Ligand, a pro-apoptotic gene recently established as a NFAT target in megakaryocytes. Together, these results suggest that DSCR1 acts as an NFAT-induced NFAT inhibitor in megakaryocytes and, when overexpressed, interferes with the expression of NFAT-dependent megakaryocytic genes.

scholarly journals Brain Endothelial miR-146a Negatively Modulates T-Cell Adhesion through Repressing Multiple Targets to Inhibit NF-κB Activation

2015 ◽  
Vol 35 (3) ◽  
pp. 412-423 ◽  
Author(s):  
Dongsheng Wu ◽  
Camilla Cerutti ◽  
Miguel A Lopez-Ramirez ◽  
Gareth Pryce ◽  
Josh King-Robson ◽  
...  
Keyword(s):  
T Cells ◽  
Endothelial Cells ◽  
Nuclear Translocation ◽  
Leukocyte Adhesion ◽  
Cell Types ◽  
Nuclear Factor ◽  
Autoimmune Encephalomyelitis ◽  
Activated T Cells ◽  
Cytokine Activation

Pro-inflammatory cytokine-induced activation of nuclear factor, NF-κB has an important role in leukocyte adhesion to, and subsequent migration across, brain endothelial cells (BECs), which is crucial for the development of neuroinflammatory disorders such as multiple sclerosis (MS). In contrast, microRNA-146a (miR-146a) has emerged as an anti-inflammatory molecule by inhibiting NF-κB activity in various cell types, but its effect in BECs during neuroinflammation remains to be evaluated. Here, we show that miR-146a was upregulated in microvessels of MS-active lesions and the spinal cord of mice with experimental autoimmune encephalomyelitis. In vitro, TNFα and IFNγ treatment of human cerebral microvascular endothelial cells (hCMEC/D3) led to upregulation of miR-146a. Brain endothelial overexpression of miR-146a diminished, whereas knockdown of miR-146a augmented cytokine-stimulated adhesion of T cells to hCMEC/D3 cells, nuclear translocation of NF-κB, and expression of adhesion molecules in hCMEC/D3 cells. Furthermore, brain endothelial miR-146a modulates NF-κB activity upon cytokine activation through targeting two novel signaling transducers, RhoA and nuclear factor of activated T cells 5, as well as molecules previously identified, IL-1 receptor-associated kinase 1, and TNF receptor-associated factor 6. We propose brain endothelial miR-146a as an endogenous NF-κB inhibitor in BECs associated with decreased leukocyte adhesion during neuroinflammation.

Abstract 439: Biomechanical Stimulation Promotes Translocation of Nuclear Factor of Activated T-cells 5 Into The Nucleus of Vascular Smooth Muscle Cells

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Maren Hödebeck ◽  
Markus Hecker ◽  
Thomas Korff
Keyword(s):  
T Cells ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Mrna Expression ◽  
Vascular Smooth Muscle Cells ◽  
Splice Variant ◽  
Nuclear Translocation ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Biomechanical Stimulation

Chronic alterations in the biomechanical stimulation of vascular smooth muscle cells (VSMC) as experienced during hypertension lead to changes in VSMC phenotype and function and further enable the structural remodeling of the vessel wall. In this context, we recently reported that an increase in wall stress or biomechanical stretch is sufficient to activate nuclear factor of activated T-cells 5 (NFAT5). This transcription factor promotes the expression of gene products such as tenascin-C and κ-actin, both involved in VSMC migration. Based on these findings, we hypothesized that biomechanical stretch elicits NFAT5 mRNA expression and induces biochemical modifications of NFAT5 on the post-translational level, a prerequisite for its entry into the nucleus and transcriptional activity. To scrutinize this hypothesis, human arterial VSMC were exposed to biomechanical stretch (13%, 0.5 Hz) and subjected to detailed mRNA expression analyses. While a ~3-fold reduction in NFAT5 splice variant 1 (isoform A) mRNA expression was observed in stretch-stimulated VSMC as compared to the static controls (n=3, p<0.05), splice variant 3 (isoform C) mRNA levels were induced ~1.8-fold (n=3, p<0.05). Overexpression of corresponding Flag-tagged NFAT5 proteins in VSMC and subsequent immunofluorescence as well as biochemical analyses revealed that isoform A was primarily located in the cytoplasm of static and stretch-stimulated VSMC while isoform C was preferentially localized in the nucleus under baseline conditions and further accumulated in the nucleus upon biomechanical stimulation (n=3, p<0.05). Nuclear translocation of isoform C was amplified for phosphorylation-deficient mutants generated by exchanging serine to alanine at position 1197 even under static culture conditions while a phosphomimetic mutation at this residue (serine to glutamate) inhibited NFAT5c nuclear translocation (n=3, p<0.05). Collectively, our findings indicate that exposure of VSMC to biomechanical stretch triggers the expression of NFAT5 isoform C and controls its entry into the nucleus via phosphorylation at S-1197. Current investigations are focusing on the impact of NFAT5 on hypertensive remodeling utilizing inducible smooth muscle cell-specific NFAT5-deficient mice.

Suppression of Nuclear Translocation of Nuclear Factor‐κB and Nuclear Factor of Activated T Cells by Younggaechulgam‐Tang

2004 ◽  
Vol 26 (4) ◽  
pp. 545-558
Author(s):  
Hye‐Young Shin ◽  
Yung‐Sun Song ◽  
Chung‐Yeon Hwang ◽  
Tae‐Yong Shin ◽  
Hyung‐Min Kim
Keyword(s):  
T Cells ◽  
Nuclear Translocation ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Activated T Cells
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