scholarly journals The Switch from NF-YAl to NF-YAs Isoform Impairs Myotubes Formation

Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 789 ◽  
Author(s):  
Debora Libetti ◽  
Andrea Bernardini ◽  
Sarah Sertic ◽  
Graziella Messina ◽  
Diletta Dolfini ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Alternative Splicing ◽  
Muscle Cells ◽  
Genetic Evidence ◽  
C2c12 Cells ◽  
Regulatory Subunit ◽  
Before And After ◽  
Myod Expression ◽  
Early Phases

NF-YA, the regulatory subunit of the trimeric transcription factor (TF) NF-Y, is regulated by alternative splicing (AS) generating two major isoforms, “long” (NF-YAl) and “short” (NF-YAs). Muscle cells express NF-YAl. We ablated exon 3 in mouse C2C12 cells by a four-guide CRISPR/Cas9n strategy, obtaining clones expressing exclusively NF-YAs (C2-YAl-KO). C2-YAl-KO cells grow normally, but are unable to differentiate. Myogenin and—to a lesser extent, MyoD— levels are substantially lower in C2-YAl-KO, before and after differentiation. Expression of the fusogenic Myomaker and Myomixer genes, crucial for the early phases of the process, is not induced. Myomaker and Myomixer promoters are bound by MyoD and Myogenin, and Myogenin overexpression induces their expression in C2-YAl-KO. NF-Y inactivation reduces MyoD and Myogenin, but not directly: the Myogenin promoter is CCAAT-less, and the canonical CCAAT of the MyoD promoter is not bound by NF-Y in vivo. We propose that NF-YAl, but not NF-YAs, maintains muscle commitment by indirectly regulating Myogenin and MyoD expression in C2C12 cells. These experiments are the first genetic evidence that the two NF-YA isoforms have functionally distinct roles.

scholarly journals Caveolin-3 Associates with Developing T-tubules during Muscle Differentiation

1997 ◽  
Vol 136 (1) ◽  
pp. 137-154 ◽  
Author(s):  
Robert G. Parton ◽  
Michael Way ◽  
Natasha Zorzi ◽  
Espen Stang
Keyword(s):  
Skeletal Muscle ◽  
Plasma Membrane ◽  
Muscle Cells ◽  
Membrane System ◽  
C2c12 Cells ◽  
Double Labeling ◽  
Specific Antibodies ◽  
T Tubules ◽  
Α1 Subunit

Caveolae, flask-shaped invaginations of the plasma membrane, are particularly abundant in muscle cells. We have recently cloned a muscle-specific caveolin, termed caveolin-3, which is expressed in differentiated muscle cells. Specific antibodies to caveolin-3 were generated and used to characterize the distribution of caveolin-3 in adult and differentiating muscle. In fully differentiated skeletal muscle, caveolin-3 was shown to be associated exclusively with sarcolemmal caveolae. Localization of caveolin-3 during differentiation of primary cultured muscle cells and development of mouse skeletal muscle in vivo suggested that caveolin-3 is transiently associated with an internal membrane system. These elements were identified as developing transverse-(T)-tubules by double-labeling with antibodies to the α1 subunit of the dihydropyridine receptor in C2C12 cells. Ultrastructural analysis of the caveolin-3– labeled elements showed an association of caveolin-3 with elaborate networks of interconnected caveolae, which penetrated the depths of the muscle fibers. These elements, which formed regular reticular structures, were shown to be surface-connected by labeling with cholera toxin conjugates. The results suggest that caveolin-3 transiently associates with T-tubules during development and may be involved in the early development of the T-tubule system in muscle.

scholarly journals Regulation of the Rapsyn Promoter by Kaiso and δ-Catenin

2004 ◽  
Vol 24 (16) ◽  
pp. 7188-7196 ◽  
Author(s):  
Marianna Rodova ◽  
Kevin F. Kelly ◽  
Michael VanSaun ◽  
Juliet M. Daniel ◽  
Michael J. Werle
Keyword(s):  
Transcription Factor ◽  
Neuromuscular Junction ◽  
Acetylcholine Receptors ◽  
Consensus Sequence ◽  
Specific Protein ◽  
C2c12 Cells ◽  
Congenital Myasthenic Syndrome ◽  
P120 Catenin ◽  
Myasthenic Syndrome

ABSTRACT Rapsyn is a synapse-specific protein that is required for clustering acetylcholine receptors at the neuromuscular junction. Analysis of the rapsyn promoter revealed a consensus site for the transcription factor Kaiso within a region that is mutated in a subset of patients with congenital myasthenic syndrome. Kaiso is a POZ-zinc finger family transcription factor which recognizes the specific core consensus sequence CTGCNA (where N is any nucleotide). Previously, the only known binding partner for Kaiso was the cell adhesion cofactor, p120 catenin. Here we show that δ-catenin, a brain-specific member of the p120 catenin subfamily, forms a complex with Kaiso. Antibodies against Kaiso and δ-catenin recognize proteins in the nuclei of C2C12 myocytes and at the postsynaptic domain of the mouse neuromuscular junction. Endogenous Kaiso in C2C12 cells coprecipitates with the rapsyn promoter in vivo as shown by chromatin immunoprecipitation assay. Minimal promoter assays demonstrated that the rapsyn promoter can be activated by Kaiso and δ-catenin; this activation is apparently muscle specific. These results provide the first experimental evidence that rapsyn is a direct sequence-specific target of Kaiso and δ-catenin. We propose a new model of synapse-specific transcription that involves the interaction of Kaiso, δ-catenin, and myogenic transcription factors at the neuromuscular junction.

scholarly journals The PI3K pathway drives the maturation of mast cells via microphthalmia transcription factor

Blood ◽  
2011 ◽  
Vol 118 (13) ◽  
pp. 3459-3469 ◽  
Author(s):  
Peilin Ma ◽  
Raghuveer Singh Mali ◽  
Veerendra Munugalavadla ◽  
Subha Krishnan ◽  
Baskar Ramdas ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Mast Cells ◽  
Pi3k Pathway ◽  
Regulatory Subunit ◽  
Growth And Survival ◽  
Src Homology 3 ◽  
Pi3k Activation ◽  
Src Homology ◽  
Microphthalmia Transcription Factor

Abstract Mast cell maturation is poorly understood. We show that enhanced PI3K activation results in accelerated maturation of mast cells by inducing the expression of microphthalmia transcription factor (Mitf). Conversely, loss of PI3K activation reduces the maturation of mast cells by inhibiting the activation of AKT, leading to reduced Mitf but enhanced Gata-2 expression and accumulation of Gr1+Mac1+ myeloid cells as opposed to mast cells. Consistently, overexpression of Mitf accelerates the maturation of mast cells, whereas Gata-2 overexpression mimics the loss of the PI3K phenotype. Expressing the full-length or the src homology 3– or BCR homology domain–deleted or shorter splice variant of the p85α regulatory subunit of PI3K or activated AKT or Mitf in p85α-deficient cells restores the maturation but not growth. Although deficiency of both SHIP and p85α rescues the maturation of SHIP−/− and p85α−/− mast cells and expression of Mitf; in vivo, mast cells are rescued in some, but not all tissues, due in part to defective KIT signaling, which is dependent on an intact src homology 3 and BCR homology domain of p85α. Thus, p85α-induced maturation, and growth and survival signals, in mast cells can be uncoupled.

scholarly journals EZN-2208 treatment suppresses chronic lymphocytic leukaemia by interfering with environmental protection and increases response to fludarabine

Open Biology ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 190262
Author(s):  
Roberta Valsecchi ◽  
Nadia Coltella ◽  
Daniela Magliulo ◽  
Lucia Bongiovanni ◽  
Lydia Scarfò ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Chronic Lymphocytic Leukaemia ◽  
Environmental Protection ◽  
Lymphocytic Leukaemia ◽  
Therapeutic Approaches ◽  
Leukaemic Cells ◽  
Induced Apoptosis ◽  
Early Phases

The transcription factor HIF-1α is overexpressed in chronic lymphocytic leukaemia (CLL), where it promotes leukaemia progression by favouring the interaction of leukaemic cells with protective tissue microenvironments. Here, we tested the hypothesis that a pharmacological compound previously shown to inhibit HIF-1α may act as a chemosensitizer by interrupting protective microenvironmental interactions and exposing CLL cells to fludarabine-induced cytotoxicity. We found that the camptothecin-11 analogue EZN-2208 sensitizes CLL cells to fludarabine-induced apoptosis in cytoprotective in vitro cultures; in vivo EZN-2208 improves fludarabine responses, especially in early phases of leukaemia expansion, and exerts significant anti-leukaemia activity, thus suggesting that this or similar compounds may be considered as effective CLL therapeutic approaches.

scholarly journals In Vivo Role of Alternative Splicing and Serine Phosphorylation of the Microphthalmia-Associated Transcription Factor

Genetics ◽  
2012 ◽  
Vol 191 (1) ◽  
pp. 133-144 ◽  
Author(s):  
Julien Debbache ◽  
M. Raza Zaidi ◽  
Sean Davis ◽  
Theresa Guo ◽  
Keren Bismuth ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Alternative Splicing ◽  
Serine Phosphorylation

Chicken ovalbumin upstream promoter-transcription factor II regulates nuclear receptor, myogenic, and metabolic gene expression in skeletal muscle cells

2011 ◽  
Vol 43 (4) ◽  
pp. 213-227 ◽  
Author(s):  
Lisa M. Crowther ◽  
Shu-Ching Mary Wang ◽  
Natalie A. Eriksson ◽  
Stephen A. Myers ◽  
Lauren A. Murray ◽  
...  
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Transcription Factor ◽  
Muscle Cells ◽  
Internal Controls ◽  
C2c12 Cells ◽  
Low Density ◽  
Factor Ii ◽  
Upstream Promoter ◽  
Chicken Ovalbumin

We demonstrate that chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) mRNA is more abundantly expressed (than COUP-TFI mRNA) in skeletal muscle C2C12 cells and in (type I and II) skeletal muscle tissue from C57BL/10 mice. Consequently, we have utilized the ABI TaqMan Low Density Array (TLDA) platform to analyze gene expression changes specifically attributable to ectopic COUP-TFII (relative to vector only) expression in muscle cells. Utilizing a TLDA-based platform and 5 internal controls, we analyze the entire NR superfamily, 96 critical metabolic genes, and 48 important myogenic regulatory genes on the TLDA platform utilizing 5 internal controls. The low density arrays were analyzed by rigorous statistical analysis (with Genorm normalization, Bioconductor R, and the Empirical Bayes statistic) using the (integromics) statminer software. In addition, we validated the differentially expressed patho-physiologically relevant gene (identified on the TLDA platform) glucose transporter type 4 (Glut4). We demonstrated that COUP-TFII expression increased the steady state levels of Glut4 mRNA and protein, while ectopic expression of truncated COUP-TFII lacking helix 12 (COUP-TFΔH12) reduced Glut4 mRNA expression in C2C12 cells. Moreover, COUP-TFII expression trans-activated the Glut4 promoter (−997/+3), and ChIP analysis identified selective recruitment of COUP-TFII to a region encompassing a highly conserved SP1 binding site (in mouse, rat, and human) at nt positions −131/−118. Mutation of the SpI site ablated COUP-TFII mediated trans-activation of the Glut4 promoter. In conclusion, this study demonstrates that in skeletal muscle cells, COUP-TFII regulates several nuclear hormone receptors, and critical metabolic and muscle specific genes.

scholarly journals Identification of Sclerostin as a Putative New Myokine Involved in the Muscle-to-Bone Crosstalk

Biomedicines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 71
Author(s):  
Maria Sara Magarò ◽  
Jessika Bertacchini ◽  
Francesca Florio ◽  
Manuela Zavatti ◽  
Francesco Potì ◽  
...  
Keyword(s):  
Bone Growth ◽  
Muscle Cells ◽  
Negative Regulator ◽  
C2c12 Cells ◽  
Inhibitory Role ◽  
Sost Gene ◽  
Endocrine Organs ◽  
Bone Cell Differentiation

Bone and muscle have been recognized as endocrine organs since they produce and secrete “hormone-like factors” that can mutually influence each other and other tissues, giving rise to a “bone–muscle crosstalk”. In our study, we made use of myogenic (C2C12 cells) and osteogenic (2T3 cells) cell lines to investigate the effects of muscle cell-produced factors on the maturation process of osteoblasts. We found that the myogenic medium has inhibitory effects on bone cell differentiation and we identified sclerostin as one of the myokines produced by muscle cells. Sclerostin is a secreted glycoprotein reportedly expressed by bone/cartilage cells and is considered a negative regulator of bone growth due to its role as an antagonist of the Wnt/β-catenin pathway. Given the inhibitory role of sclerostin in bone, we analyzed its expression by muscle cells and how it affects bone formation and homeostasis. Firstly, we characterized and quantified sclerostin synthesis by a myoblast cell line (C2C12) and by murine primary muscle cells by Western blotting, real-time PCR, immunofluorescence, and ELISA assay. Next, we investigated in vivo production of sclerostin in distinct muscle groups with different metabolic and mechanical loading characteristics. This analysis was done in mice of different ages (6 weeks, 5 and 18 months after birth) and revealed that sclerostin expression is dynamically modulated in a muscle-specific way during the lifespan. Finally, we transiently expressed sclerostin in the hind limb muscles of young mice (2 weeks of age) via in vivo electro-transfer of a plasmid containing the SOST gene in order to investigate the effects of muscle-specific overproduction of the protein. Our data disclosed an inhibitory role of the muscular sclerostin on the bones adjacent to the electroporated muscles. This observation suggests that sclerostin released by skeletal muscle might synergistically interact with osseous sclerostin and potentiate negative regulation of osteogenesis possibly by acting in a paracrine/local fashion. Our data point out a role for muscle as a new source of sclerostin.

scholarly journals Myogenic conversion of mammalian fibroblasts induced by differentiating muscle cells

1995 ◽  
Vol 108 (8) ◽  
pp. 2733-2739 ◽  
Author(s):  
G. Salvatori ◽  
L. Lattanzi ◽  
M. Coletta ◽  
S. Aguanno ◽  
E. Vivarelli ◽  
...  
Keyword(s):  
Muscle Fibre ◽  
Striated Muscle ◽  
Muscle Cells ◽  
Cell Types ◽  
Sole Source ◽  
Cell Interaction ◽  
C2c12 Cells ◽  
Membrane Function ◽  
Beta Galactosidase

Somite-derived skeletal myoblasts are supposed to be the sole source of muscle fibre nuclei during pre- and postnatal development, but evidence is accumulating for unorthodox contributions to muscle fibre nuclei from other cell types. For example, in tissue culture, fibroblasts can fuse with dysgenic myoblasts and restore correct membrane function. We report here the results of a series of experiments investigating this phenomenon and its possible mechanism. 10T1/2 cells, infected with a replication defective retrovirus encoding the bacterial enzyme beta-galactosidase, fused to form beta-galactosidase positive, differentiated myotubes when cocultured with differentiating uninfected C2C12 or primary myogenic cells, but this did not occur when they were cocultured with other cells such as 3T3 fibroblasts or PC12 pheochromocytoma cells. Myogenic conversion ranged from 1 to 10% of the 10T1/2 cell population and required close cell interaction between the different cells types: it was not induced by conditioned medium or extracellular matrix deposited by C2C12 cells. Myogenic conversion was also observed in vivo, after injection of similarly infected 10T1/2 cells into regenerating muscle. Conversion was seen also after coculture of uninfected 10T1/2 cells with primary chick myoblasts, thus demonstrating that it was not dependent upon viral infection and that there is no species or class barrier in this phenomenon. Primary fibroblasts, isolated from different organs of transgenic mice carrying a Lac Z marker under the control of a muscle-specific promoter, restricting beta-galactosidase expression to striated muscle cells, also underwent myogenic conversion, when cocultured with C2C12 myoblasts.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals miR-203 imposes an intrinsic barrier during cellular reprogramming by targeting NFATC2

2020 ◽  
Author(s):  
María Salazar-Roa ◽  
Sara Martínez-Martínez ◽  
Osvaldo Graña-Castro ◽  
Mónica Álvarez-Fernández ◽  
Marianna Trakala ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Cellular Reprogramming ◽  
Pluripotent Cells ◽  
Multiple Functions ◽  
Genetic Ablation ◽  
Cellular Models ◽  
Reprogramming Factors ◽  
Early Phases

AbstractCellular reprogramming from somatic to pluripotent cells is the basis for multiple applications aimed to replace damaged tissues in regenerative medicine. However, this process is limited by intrinsic barriers that are induced in response to reprogramming factors. In this manuscript we report that miR-203, a microRNA with multiple functions in differentiation and tumor suppression, acts as an endogenous barrier to reprogramming. Genetic ablation of miR-203 results in enhanced reprogramming whereas its expression prevents the formation of pluripotent cells both in vitro and in vivo. Mechanistically, this effect correlates with the direct repression of NFATC2, a transcription factor involved in the early phases of reprogramming. Inhibition of NFATC2 mimics miR-203 effects whereas NFATC2 overexpression rescues inducible cell pluripotency in miR-203-overexpressing cultures. These data suggest that miR-203 repression may favor the efficiency of reprogramming in a variety of cellular models.

scholarly journals Disruption of CK2β in Embryonic Neural Stem Cells Compromises Proliferation and Oligodendrogenesis in the Mouse Telencephalon

2010 ◽  
Vol 30 (11) ◽  
pp. 2737-2749 ◽  
Author(s):  
Emmanuelle Huillard ◽  
Léa Ziercher ◽  
Olivier Blond ◽  
Michael Wong ◽  
Jean-Christophe Deloulme ◽  
...  
Keyword(s):  
Transcription Factor ◽  
System Development ◽  
Nervous System Development ◽  
Conditional Knockout ◽  
Regulatory Subunit ◽  
Bhlh Transcription Factor ◽  
Helix Loop Helix ◽  
Proliferation And Differentiation

ABSTRACT Genetic programs that govern neural stem/progenitor cell (NSC) proliferation and differentiation are dependent on extracellular cues and a network of transcription factors, which can be regulated posttranslationally by phosphorylation. However, little is known about the kinase-dependent pathways regulating NSC maintenance and oligodendrocyte development. We used a conditional knockout approach to target the murine regulatory subunit (beta) of protein kinase casein kinase 2 (CK2β) in embryonic neural progenitors. Loss of CK2β leads to defects in proliferation and differentiation of embryonic NSCs. We establish CK2β as a key positive regulator for the development of oligodendrocyte precursor cells (OPCs), both in vivo and in vitro. We show that CK2β directly interacts with the basic helix-loop-helix (bHLH) transcription factor Olig2, a critical modulator of OPC development, and activates the CK2-dependent phosphorylation of its serine-threonine-rich (STR) domain. Finally, we reveal that the CK2-targeted STR domain is required for the oligodendroglial function of Olig2. These findings suggest that CK2 may control oligodendrogenesis, in part, by regulating the activity of the lineage-specific transcription factor Olig2. Thus, CK2β appears to play an essential and uncompensated role in central nervous system development.

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