CREB-mediated transcriptional activation of NRMT1 drives muscle differentiation

The N-terminal methyltransferase NRMT1 is an important regulator of protein-DNA interactions and plays a role in many cellular processes, including mitosis, cell cycle progression, chromatin organization, DNA damage repair, and transcriptional regulation. Accordingly, loss of NRMT1 results in both developmental pathologies and oncogenic phenotypes. Though NRMT1 plays such important and diverse roles in the cell, little is known about its own regulation. To better understand the mechanisms governing NRMT1 expression, we first identified its predominant transcriptional start site and minimal promoter region with predicted transcription factor motifs. We then used a combination of luciferase and binding assays to confirm CREB1 as the major regulator of NRMT1 transcription. We tested which conditions known to activate CREB1 also activated NRMT1 transcription, and found CREB1-mediated NRMT1 expression was increased during recovery from serum starvation and muscle cell differentiation. To determine how NRMT1 expression affects myoblast differentiation, we used CRISPR/Cas9 technology to knock out NRMT1 expression in immortalized C2C12 mouse myoblasts. C2C12 cells depleted of NRMT1 lacked Pax7 expression and were unable to proceed down the muscle differentiation pathway. Instead, they took on characteristics of C2C12 cells that have transdifferentiated into osteoblasts, including increased alkaline phosphatase and type I collagen expression and decreased proliferation. These data implicate NRMT1 as an important downstream target of CREB1 during muscle cell differentiation.

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SRF is a nonhistone methylation target of KDM2B and SET7 in the regulation of skeletal muscle differentiation

Experimental & Molecular Medicine ◽

10.1038/s12276-021-00564-4 ◽

2021 ◽

Vol 53 (2) ◽

pp. 250-263

Author(s):

Duk-Hwa Kwon ◽

Joo-Young Kang ◽

Hosouk Joung ◽

Ji-Young Kim ◽

Anna Jeong ◽

...

Keyword(s):

Skeletal Muscle ◽

Cell Differentiation ◽

Muscle Cell ◽

Transcriptional Activation ◽

Serum Response Factor ◽

Muscle Differentiation ◽

Skeletal Muscle Differentiation ◽

Muscle Cell Differentiation ◽

Lysine Residues ◽

Serum Response

AbstractThe demethylation of histone lysine residues, one of the most important modifications in transcriptional regulation, is associated with various physiological states. KDM2B is a demethylase of histones H3K4, H3K36, and H3K79 and is associated with the repression of transcription. Here, we present a novel mechanism by which KDM2B demethylates serum response factor (SRF) K165 to negatively regulate muscle differentiation, which is counteracted by the histone methyltransferase SET7. We show that KDM2B inhibited skeletal muscle differentiation by inhibiting the transcription of SRF-dependent genes. Both KDM2B and SET7 regulated the balance of SRF K165 methylation. SRF K165 methylation was required for the transcriptional activation of SRF and for the promoter occupancy of SRF-dependent genes. SET7 inhibitors blocked muscle cell differentiation. Taken together, these data indicate that SRF is a nonhistone target of KDM2B and that the methylation balance of SRF as maintained by KDM2B and SET7 plays an important role in muscle cell differentiation.

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SRF is a non-histone methylation target of KDM2B and SET7 in the regulation of myogenesis

10.1101/2020.04.17.046342 ◽

2020 ◽

Author(s):

Hosouk Joung ◽

Joo-Young Kang ◽

Ji-Young Kim ◽

Duk-Hwa Kwon ◽

Anna Jeong ◽

...

Keyword(s):

Cell Differentiation ◽

Muscle Cell ◽

Transcriptional Activation ◽

Serum Response Factor ◽

Muscle Differentiation ◽

Skeletal Muscle Differentiation ◽

Muscle Cell Differentiation ◽

Histone H3k4 ◽

Promoter Occupancy ◽

Serum Response

AbstractDemethylation of histone lysines, one of the most important modifications in transcriptional regulation, is associated with various physiological states. KDM2B is a histone H3K4, H3K36, and H3K79 demethylase associated with the repression of transcription. Here, we present a novel mechanism by which KDM2B demethylates serum response factor (SRF) K165 to negatively regulate muscle differentiation, which is counteracted by histone methyltransferase SET7. We show that KDM2B inhibited skeletal muscle differentiation by inhibiting the transcription of SRF-dependent genes. Both KDM2B and SET7 regulated the balance of SRF K165 methylation. SRF K165 methylation was required for the transcriptional activation of SRF and for the promoter occupancy of SRF-dependent genes. SET7 inhibitors blocked muscle cell differentiation. Taken together, these data indicate that SRF is a non-histone target of KDM2B and that the methylation balance of SRF maintained by KDM2B and SET7 plays an important role in muscle cell differentiation.

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Smad7 Promotes and Enhances Skeletal Muscle Differentiation

Molecular and Cellular Biology ◽

10.1128/mcb.00384-06 ◽

2006 ◽

Vol 26 (16) ◽

pp. 6248-6260 ◽

Cited By ~ 54

Author(s):

Helen D. Kollias ◽

Robert L. S. Perry ◽

Tetsuaki Miyake ◽

Arif Aziz ◽

John C. McDermott

Keyword(s):

Skeletal Muscle ◽

Cell Differentiation ◽

Muscle Cell ◽

Muscle Differentiation ◽

Skeletal Muscle Cell ◽

Proximal Promoter ◽

Cytokine Signaling ◽

Skeletal Muscle Differentiation ◽

Muscle Cell Differentiation ◽

Tgf Β1

ABSTRACT Transforming growth factor β1 (TGF-β1) and myostatin signaling, mediated by the same Smad downstream effectors, potently repress skeletal muscle cell differentiation. Smad7 inhibits these cytokine signaling pathways. The role of Smad7 during skeletal muscle cell differentiation was assessed. In these studies, we document that increased expression of Smad7 abrogates myostatin- but not TGF-β1-mediated repression of myogenesis. Further, constitutive expression of exogenous Smad7 potently enhanced skeletal muscle differentiation and cellular hypertrophy. Conversely, targeting of endogenous Smad7 by small interfering RNA inhibited C2C12 muscle cell differentiation, indicating an essential role for Smad7 during myogenesis. Congruent with a role for Smad7 in myogenesis, we observed that the muscle regulatory factor (MyoD) binds to and transactivates the Smad7 proximal promoter region. Finally, we document that Smad7 directly interacts with MyoD and enhances MyoD transcriptional activity. Thus, Smad7 cooperates with MyoD, creating a positive loop to induce Smad7 expression and to promote MyoD driven myogenesis. Taken together, these data implicate Smad7 as a fundamental regulator of differentiation in skeletal muscle cells.

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Regulation of the muscle-specific expression and function of an ascidian T-box gene, As-T2

Development ◽

10.1242/dev.128.19.3717 ◽

2001 ◽

Vol 128 (19) ◽

pp. 3717-3728

Author(s):

Yasuo Mitani ◽

Hiroki Takahashi ◽

Nori Satoh

Keyword(s):

Cell Differentiation ◽

Muscle Cell ◽

Muscle Differentiation ◽

Precursor Cells ◽

Paraxial Mesoderm ◽

Specific Expression ◽

Binding Motifs ◽

T Box ◽

Muscle Cell Differentiation ◽

Endodermal Cells

The Tbx6 T-box genes are expressed in somite precursor cells of vertebrate embryos and are essential for the differentiation of paraxial mesoderm. However, it is unclear how spatial regulation of the gene expression is controlled and how the genes function to promote muscle differentiation. The Tbx6-related gene As-T2 of the ascidian Halocynthia roretzi is first expressed very transiently in endodermal cells around the 32-∼44-cell stage, is then expressed distinctly and continuously in muscle precursor cells, and later in epidermal cells situated in the distal tip region of the elongating tail. We now show that inhibition of As-T2-mediated transcriptional activation by microinjection of As-T2/EnR into one-cell embryos resulted in suppression of the expression of the muscle-specific actin gene (HrMA4) and myosin heavy chain gene (HrMHC), but the injection did not affect the differentiation of endodermal cells or tail tip cells, suggesting that the primary function of As-T2 is associated with muscle cell differentiation. The 5′ flanking region of As-T2 contains two promoter modules that regulate its specific expression: a distal module that responsible for its specific expression in the tail, and a proximal module required for its muscle-specific expression. Around the proximal module, there are two putative T protein-binding motifs (TTCACACTT). Co-injection of an As-T2/lacZ construct with or without the T-binding motifs together with As-T2 mRNA revealed that these motifs are essential for autoregulatory activation of the gene itself. In addition, we found that the minimal promoter regions of HrMA4 and HrMHC contain T-binding motifs. Co-injection of HrMA4/lacZ or HrMHC/lacZ containing the T-binding motifs along with As-T2 mRNA revealed that As-T2 protein binds to these motifs to upregulate the gene activity. Taking into account the recent finding of maternal molecules for muscle differentiation, we propose a model for a genetic cascade that includes As-T2 as a regulator of muscle cell differentiation in the ascidian embryo.

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Analysis of potential regulatory LncRNAs and CircRNAs in the oxidative myofiber and glycolytic myofiber of chickens

Scientific Reports ◽

10.1038/s41598-021-00176-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Xiaojun Ju ◽

Yifan Liu ◽

Yanju Shan ◽

Gaige Ji ◽

Ming Zhang ◽

...

Keyword(s):

Cell Differentiation ◽

Signaling Pathway ◽

Muscle Cell ◽

Regulatory Mechanism ◽

Functional Enrichment ◽

Differentially Expressed ◽

Myoblast Differentiation ◽

Integrated Analysis ◽

Muscle Cell Differentiation ◽

Myofiber Type

AbstractSART and PMM are mainly composed of oxidative myofibers and glycolytic myofibers, respectively, and myofiber types profoundly influence postnatal muscle growth and meat quality. SART and PMM are composed of lncRNAs and circRNAs that participate in myofiber type regulation. To elucidate the regulatory mechanism of myofiber type, lncRNA and circRNA sequencing was used to systematically compare the transcriptomes of the SART and PMM of Chinese female Qingyuan partridge chickens at their marketing age. The luminance value (L*), redness value (a*), average diameter, cross-sectional area, and density difference between the PMM and SART were significant (p < 0.05). ATPase staining results showed that PMMs were all darkly stained and belonged to the glycolytic type, and the proportion of oxidative myofibers in SART was 81.7%. A total of 5 420 lncRNAs were identified, of which 365 were differentially expressed in the SART compared with the PMM (p < 0.05). The cis-regulatory analysis identified target genes that were enriched for specific GO terms and KEGG pathways (p < 0.05), including striated muscle cell differentiation, regulation of cell proliferation, regulation of muscle cell differentiation, myoblast differentiation, regulation of myoblast differentiation, and MAPK signaling pathway. Pathways and coexpression network analyses suggested that XR_003077811.1, XR_003072304.1, XR_001465942.2, XR_001465741.2, XR_001470487.1, XR_003077673.1 and XR_003074785.1 played important roles in regulating oxidative myofibers by TBX3, QKI, MYBPC1, CALM2, and PPARGC1A expression. A total of 10 487 circRNAs were identified, of which 305 circRNAs were differentially expressed in the SART compared with the PMM (p < 0.05). Functional enrichment analysis showed that differentially expressed circRNAs were involved in host gene expression and were enriched in the AMPK, calcium signaling pathway, FoxO signaling pathway, p53 signaling pathway, and cellular senescence. Novel_circ_004282 and novel_circ_002121 played important roles in regulating oxidative myofibers by PPP3CA and NFATC1 expression. Using lncRNA-miRNA/circRNA-miRNA integrated analysis, we identified many candidate interaction networks that might affect muscle fiber performance. Important lncRNA-miRNA-mRNA networks, such as lncRNA-XR_003074785.1/miR-193-3p/PPARGC1A, regulate oxidative myofibers. This study reveals that lncXR_003077811.1, lncXR_003072304.1, lncXR_001465942.2, lncXR_001465741.2, lncXR_001470487.1, lncXR_003077673.1, XR_003074785.1, novel_circ_004282 and novel_circ_002121 might regulate oxidative myofibers. The lncRNA-XR_003074785.1/miR-193-3p/PPARGC1A pathway might regulate oxidative myofibers. All these findings provide rich resources for further in-depth research on the regulatory mechanism of lncRNAs and circRNAs in myofibers.

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Hormonal stimulation of myoblast differentiation in the absence of DNA synthesis

AJP Cell Physiology ◽

10.1152/ajpcell.1982.243.5.c278 ◽

1982 ◽

Vol 243 (5) ◽

pp. C278-C284 ◽

Cited By ~ 39

Author(s):

K. A. Turo ◽

J. R. Florini

Keyword(s):

Creatine Kinase ◽

Cell Differentiation ◽

Dna Synthesis ◽

Muscle Cell ◽

Fold Increase ◽

Cell Types ◽

Myoblast Differentiation ◽

Hormonal Stimulation ◽

Muscle Cell Differentiation ◽

Stimulation Of

The role of DNA synthesis in the final stages of muscle cell differentiation has been a subject of controversy for more than a decade. In an attempt to resolve disagreements over the necessity for a unique (or "quantal") mitosis just prior to the conversion of proliferating myoblasts to form postmitotic myotubes, we have studied the effects of insulin and somatomedin on the stimulation of myoblast differentiation with or without DNA synthesis. Under conditions in which at least 95% of [3H]thymidine incorporation was blocked by cytosine arabinoside, there was a 5- to 10-fold increase in the extent of differentiation (determined as fusion or creatine kinase elevation) on addition of insulin or multiplication-stimulating activity. The effect of the hormones was on myoblast differentiation, not enzyme induction; insulin did not cause any increase in creatine kinase when it was added to performed myotubes. These studies were done using two different cell types, Yaffe's L6 cell line and Japanese quail myoblasts in serum-free media; we obtained similar results in both. Our results are not compatible with the view that a quantal mitosis is required at a late stage of muscle cell differentiation.

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Ion Channels and Transporters in Muscle Cell Differentiation

International Journal of Molecular Sciences ◽

10.3390/ijms222413615 ◽

2021 ◽

Vol 22 (24) ◽

pp. 13615

Author(s):

Lingye Chen ◽

Fatemeh Hassani Nia ◽

Tobias Stauber

Keyword(s):

Stem Cells ◽

Cell Differentiation ◽

Ion Channels ◽

Muscle Cell ◽

Critical Role ◽

Cardiac Differentiation ◽

Model Organisms ◽

Myoblast Differentiation ◽

Resting Membrane Potential ◽

Muscle Cell Differentiation

Investigations on ion channels in muscle tissues have mainly focused on physiological muscle function and related disorders, but emerging evidence supports a critical role of ion channels and transporters in developmental processes, such as controlling the myogenic commitment of stem cells. In this review, we provide an overview of ion channels and transporters that influence skeletal muscle myoblast differentiation, cardiac differentiation from pluripotent stem cells, as well as vascular smooth muscle cell differentiation. We highlight examples of model organisms or patients with mutations in ion channels. Furthermore, a potential underlying molecular mechanism involving hyperpolarization of the resting membrane potential and a series of calcium signaling is discussed.

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25-hydroxyvitamin D upregulates L6 muscle cell differentiation induced by mononuclear cells via the Notch signaling pathway

10.21203/rs.3.rs-156796/v1 ◽

2021 ◽

Author(s):

Carla Domingues-Faria ◽

Stéphanie Rougé ◽

Véronique Patrac ◽

Jérôme Salles ◽

Stéphane Walrand ◽

...

Keyword(s):

Cell Differentiation ◽

Mrna Expression ◽

Muscle Cell ◽

Immune Cells ◽

Mononuclear Cells ◽

Notch Pathway ◽

Muscle Differentiation ◽

Notch Signaling Pathway ◽

Muscle Cell Differentiation

Abstract During muscle regeneration, myoblasts engage in cross-talk with immune cells to achieve optimal proliferation and differentiation. In this process, cytokines secreted by immune cells are described to modulate the kinetic of muscle differentiation. Taking into account that immune and muscle cells are both targets of vitamin D, we investigated in vitro the impact of 25-hydroxyvitamin D (25(OH)D) on the transcriptional response of muscle cells in presence of mononuclear cells. To address this objective, an in vitro model of co-culture using L6 myogenic cell line and peripheral blood mononuclear cell (PBMC) isolated from rat was used and compared to L6 cultured alone. Cells were treated with 25(OH)D (125 nM) during the 6 days of differentiation. Gene expression of 25(OH)D metabolism actors, muscle differentiation and metabolism markers, and of Notch signaling pathway effectors were studied in L6 cells by qPCR. In mono-cultured L6 cells, a 25(OH)D treatment induced a 3-fold increase (p < 0.05) in VDR mRNA expression at 24 h while no change in mRNA expression of the muscle differentiation markers i.e. Myog, Myh2 and Des was observed. In the presence of PBMCs, the mRNA expression of these markers was enhanced (27.5 times for myogenin, p < 0.05) resulting in an overexpression of the Notch pathway effectors (Dll: 6.8-fold and Hes1: x3.8-fold, p < 0.05). The 25(OH)D counteracted these effects of the PBMCs on L6 gene expression with the exception of the interleukin 6 transcript and protein. In the present study, our in vitro approach demonstrates the importance of immune cells in stimulating muscle cell differentiation. Taken as a whole, the data show that 25(OH)D attenuates in vitro the Notch pathway-dependent effects of immune cells on muscle cell differentiation and energy metabolism.

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