The calcineurin-NFAT pathway and muscle fiber-type gene expression

2000 ◽  
Vol 279 (4) ◽  
pp. C915-C924 ◽  
Author(s):  
Steven J. Swoap ◽  
R. Bridge Hunter ◽  
Eric J. Stevenson ◽  
Heather Mitchell Felton ◽  
Nilesh V. Kansagra ◽  
...  
Keyword(s):  
Gene Expression ◽  
Fiber Type ◽  
Fast Muscle ◽  
C2c12 Myotubes ◽  
Specific Gene ◽  
Activated T Cells ◽  
Adult Skeletal Muscle ◽  
Specific Gene Expression ◽  
Expression Plasmids

To test for a role of the calcineurin-NFAT (nuclear factor of activated T cells) pathway in the regulation of fiber type-specific gene expression, slow and fast muscle-specific promoters were examined in C2C12 myotubes and in slow and fast muscle in the presence of calcineurin or NFAT2 expression plasmids. Overexpression of active calcineurin in myotubes induced both fast and slow muscle-specific promoters but not non-muscle-specific reporters. Overexpression of NFAT2 in myotubes did not activate muscle-specific promoters, although it strongly activated an NFAT reporter. Thus overexpression of active calcineurin activates transcription of muscle-specific promoters in vitro but likely not via the NFAT2 transcription factor. Slow myosin light chain 2 (MLC2) and fast sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA1) reporter genes injected into rat soleus (slow) and extensor digitorum longus (EDL) (fast) muscles were not activated by coinjection of activated calcineurin or NFAT2 expression plasmids. However, an NFAT reporter was strongly activated by overexpression of NFAT2 in both muscle types. Calcineurin and NFAT protein expression and binding activity to NFAT oligonucleotides were different in slow vs. fast muscle. Taken together, these results indicate that neither calcineurin nor NFAT appear to have dominant roles in the induction and/or maintenance of slow or fast fiber type in adult skeletal muscle. Furthermore, different pathways may be involved in muscle-specific gene expression in vitro vs. in vivo.

scholarly journals Epigenetic regulation of neural cell differentiation plasticity in the adult mammalian brain

2008 ◽  
Vol 105 (46) ◽  
pp. 18012-18017 ◽  
Author(s):  
Jun Kohyama ◽  
Takuro Kojima ◽  
Eriko Takatsuka ◽  
Toru Yamashita ◽  
Jun Namiki ◽  
...  
Keyword(s):  
Gene Expression ◽  
Target Genes ◽  
Epigenetic Modification ◽  
Mammalian Brain ◽  
Cytokine Signaling ◽  
Specific Gene ◽  
Neural Cells ◽  
Specific Gene Expression

Neural stem/progenitor cells (NSCs/NPCs) give rise to neurons, astrocytes, and oligodendrocytes. It has become apparent that intracellular epigenetic modification including DNA methylation, in concert with extracellular cues such as cytokine signaling, is deeply involved in fate specification of NSCs/NPCs by defining cell-type specific gene expression. However, it is still unclear how differentiated neural cells retain their specific attributes by repressing cellular properties characteristic of other lineages. In previous work we have shown that methyl-CpG binding protein transcriptional repressors (MBDs), which are expressed predominantly in neurons in the central nervous system, inhibit astrocyte-specific gene expression by binding to highly methylated regions of their target genes. Here we report that oligodendrocytes, which do not express MBDs, can transdifferentiate into astrocytes both in vitro (cytokine stimulation) and in vivo (ischemic injury) through the activation of the JAK/STAT signaling pathway. These findings suggest that differentiation plasticity in neural cells is regulated by cell-intrinsic epigenetic mechanisms in collaboration with ambient cell-extrinsic cues.

scholarly journals Alcohol exposure impairs trophoblast survival and alters subtype-specific gene expression in vitro

Placenta ◽  
2016 ◽  
Vol 46 ◽  
pp. 87-91 ◽  
Author(s):  
J.I. Kalisch-Smith ◽  
J.E. Outhwaite ◽  
D.G. Simmons ◽  
M. Pantaleon ◽  
K.M. Moritz
Keyword(s):  
Gene Expression ◽  
Alcohol Exposure ◽  
Specific Gene ◽  
Specific Gene Expression

Characterization of hematopoietic lineage-specific gene expression by ES cell in vitro differentiation induction system

Blood ◽  
2000 ◽  
Vol 95 (3) ◽  
pp. 870-878 ◽  
Author(s):  
Takumi Era ◽  
Toshiaki Takagi ◽  
Tomomi Takahashi ◽  
Jean-Christophe Bories ◽  
Toru Nakano
Keyword(s):  
Gene Expression ◽  
Cell Lines ◽  
Embryonic Stem ◽  
Experimental System ◽  
Specific Gene ◽  
Specific Gene Expression ◽  
Differentiation Induction ◽  
Lineage Specific Gene ◽  
Megakaryocytic Cell

The continuous generation of mature blood cells from hematopoietic progenitor cells requires a highly complex series of molecular events. To examine lineage-specific gene expression during the differentiation process, we developed a novel method combiningLacZ reporter gene analysis with in vitro hematopoietic differentiation induction from mouse embryonic stem cells. For a model system using this method, we chose the erythroid and megakaryocytic differentiation pathways. Although erythroid and megakaryocytic cells possess distinct functional and morphologic features, these 2 lineages originate from bipotential erythro-megakaryocytic progenitors and share common lineage-restricted transcription factors. A portion of the 5′ flanking region of the human glycoprotein IIb (IIb) integrin gene extending from base −598 to base +33 was examined in detail. As reported previously, this region is sufficient for megakaryocyte-specific gene expression. However, previous reports that used human erythro-megakaryocytic cell lines suggested that one or more negative regulatory regions were necessary for megakaryocyte-specific gene expression. Our data clearly showed that an approximately 200-base enhancer region extending from −598 to −400 was sufficient for megakaryocyte-specific gene expression. This experimental system has advantages over those using erythro-megakaryocytic cell lines because it recapitulates normal hematopoietic cell development and differentiation. Furthermore, this system is more efficient than transgenic analysis and can easily examine gene expression with null mutations of specific genes.

Prolonged down regulation of specific gene expression in nucleus pulposus cell mediated by RNA interference in vitro

2006 ◽  
Vol 24 (6) ◽  
pp. 1271-1278 ◽  
Author(s):  
Kenichiro Kakutani ◽  
Kotaro Nishida ◽  
Koki Uno ◽  
Toru Takada ◽  
Takatoshi Shimomura ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rna Interference ◽  
Nucleus Pulposus ◽  
Nucleus Pulposus Cell ◽  
Specific Gene ◽  
Down Regulation ◽  
Specific Gene Expression

Melanocyte-specific gene expression: role of repression and identification of a melanocyte-specific factor, MSF

1994 ◽  
Vol 14 (5) ◽  
pp. 3494-3503
Author(s):  
U Yavuzer ◽  
C R Goding
Keyword(s):  
Gene Expression ◽  
Mutational Analysis ◽  
Site Directed Mutagenesis ◽  
Specific Factor ◽  
Specific Gene ◽  
Binding Motif ◽  
Specific Expression ◽  
Tissue Specific ◽  
Specific Gene Expression

For a gene to be transcribed in a tissue-specific fashion, expression must be achieved in the appropriate cell type and also be prevented in other tissues. As an approach to understanding the regulation of tissue-specific gene expression, we have analyzed the requirements for melanocyte-specific expression of the tyrosinase-related protein 1 (TRP-1) promoter. Positive regulation of TRP-1 expression is mediated by both an octamer-binding motif and an 11-bp element, termed the M box, which is conserved between the TRP-1 and other melanocyte-specific promoters. We show here that, consistent with its ability to activate transcription in a non-tissue-specific fashion, the M box binds the basic-helix-loop-helix factor USF in vitro. With the use of a combination of site-directed mutagenesis and chimeric promoter constructs, additional elements involved in regulating TRP-1 expression were identified. These include the TATA region, which appears to contribute to the melanocyte specificity of the TRP-1 promoter. Mutational analysis also identified two repressor elements, one at the start site, the other located at -240, which function both in melanoma and nonmelanoma cells. In addition, a melanocyte-specific factor, MSF, binds to sites which overlap both repressor elements, with substitution mutations demonstrating that binding by MSF is not required for repression. Although a functional role for MSF has not been unequivocally determined, the location of its binding sites leads us to speculate that it may act as a melanocyte-specific antirepressor during transcription of the endogenous TRP-1 gene.

Rituximab Induces an Interferon Gene Expression Signature in Patients with CLL.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4988-4988
Author(s):  
Elinor Lee ◽  
Xiuli Xu ◽  
Peter Munson ◽  
Ronald Cooper ◽  
Nalini Raghavachari ◽  
...  
Keyword(s):  
Gene Expression ◽  
B Cells ◽  
Gene Expression Signature ◽  
Specific Gene ◽  
Cytokine Release ◽  
Cytokine Release Syndrome ◽  
Ifn Gamma ◽  
Expression Signature ◽  
Specific Gene Expression

Abstract Rituximab, a monoclonal anti-CD20 antibody, is used to treat Chronic Lymphocytic Leukemia (CLL) in combination with fludarabine. Rituximab is thought to deplete B-cells through antibody-dependent cellular cytotoxicity, complement-dependent cytotoxicity, and possibly signaling for apoptosis. Whether or not signaling by rituximab contributes to its clinical efficacy and can sensitize the malignant cells to chemotherapy is controversial. To investigate if rituximab can induce a specific gene expression signature, we used genomic-scale gene expression profiling (Affymetrix HU133A 2.0 arrays) of B-cells from CLL patients receiving their first rituximab infusion. During the infusion, patients experienced a cytokine release syndrome (fever, chills, and hypotension) that led to interruption and symptomatic treatment in most; however, all patients were able to finish the treatment. Absolute lymphocyte counts decreased on average by 50% over this initial 24h period. We analyzed CD19+ selected CLL cells from eight patients obtained pre and 6 and 24 hours after the start of rituximab. A one-way ANOVA test was used to identify genes up- or down-regulated with a false discovery rate (FDR = number of expected chance findings / number of observations) of <10%. We identified 80 genes with at least 1.5× higher expression at 6h versus 0h including many interferon (IFN)-regulated genes like IRF1, IFITM1, STAT1, JAK3 and several apoptosis related genes such as FAS and Caspase 8. The majority of these genes were at least 2-fold up-regulated at 6 hours, but most returned to pre-treatment levels by 24 hours. Thus, rituximab induced a transient gene expression signature that correlated with the cytokine release syndrome during the infusion. To determine whether or not this IFN signature was caused directly by rituximab signaling or indirectly by cytokines released during the infusion, we compared rituximab and IFN gamma effects on CLL cells in-vitro. Both rituximab (10ug/ml with cross-linking) and IFN-gamma (1000U/ml) induced FAS (CD95) expression in CLL cells measured by flow cytometry. CD95 expression was low on untreated CLL cells, at 6 hours, up-regulation of CD95 expression with rituximab was stronger than with IFN, while at 24 hours, IFN treated cells showed slightly higher CD95 expression. Next, we investigated whether rituximab is able to activate STAT1, the main transcription factor regulating IFN target genes. IFN gamma induced rapid phosphorylation of STAT1 in CLL cells, but rituximab did not. However, we observed phosphorylation of ERK in response to rituximab as has been reported by others. After in-vitro stimulation with rituximab and IFN-gamma, IRF-1 and STAT-1 were up-regulated at 2 and 6 hours as measured by real time PCR, albeit with a stronger response after IFN. We conclude that rituximab is associated with a specific gene expression signature in CLL patients that is characterized by IFN response genes. At this point, we cannot rule out that this signature is contributed in part by cytokines released during the rituximab infusion. However, the rapid up-regulation of CD95, STAT1, and IRF1 under controlled in-vitro conditions is consistent with a direct effect of rituximab. Ongoing studies aim to better characterize rituximab signaling in CLL and to determine whether this can contribute to apoptosis or sensitize the leukemic cells to chemotherapy.

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