A novel long non-coding RNA Myolinc regulates myogenesis through TDP-43 and Filip1

Abstract Myogenesis is a complex process required for skeletal muscle formation during embryonic development and for regeneration and growth of myofibers in adults. Accumulating evidence suggests that long non-coding RNAs (lncRNAs) play key roles in regulating cell fate decision and function in various tissues. However, the role of lncRNAs in the regulation of myogenesis remains poorly understood. In this study, we identified a novel muscle-enriched lncRNA called ‘Myolinc (AK142388)’, which we functionally characterized in the C2C12 myoblast cell line. Myolinc is predominately localized in the nucleus, and its levels increase upon induction of the differentiation. Knockdown of Myolinc impairs the expression of myogenic regulatory factors and formation of multi-nucleated myotubes in cultured myoblasts. Myolinc also regulates the expression of Filip1 in a cis-manner. Similar to Myolinc, knockdown of Filip1 inhibits myogenic differentiation. Furthermore, Myolinc binds to TAR DNA-binding protein 43 (TDP-43), a DNA/RNA-binding protein that regulates the expression of muscle genes (e.g. Acta1 and MyoD). Knockdown of TDP-43 inhibits myogenic differentiation. We also show that Myolinc−TDP-43 interaction is essential for the binding of TDP-43 to the promoter regions of muscle marker genes. Finally, we show that silencing of Myolinc inhibits skeletal muscle regeneration in adult mice. Altogether, our study identifies a novel lncRNA that controls key regulatory networks of myogenesis.

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RNA-Binding Proteins Direct Myogenic Cell Fate Decisions

10.1101/2021.03.14.435333 ◽

2021 ◽

Author(s):

Joshua R. Wheeler ◽

Oscar N. Whitney ◽

Thomas O. Vogler ◽

Eric D. Nguyen ◽

Bradley Pawlikowski ◽

...

Keyword(s):

Skeletal Muscle ◽

Cell Fate ◽

Tissue Regeneration ◽

Neuromuscular Disease ◽

Binding Proteins ◽

Rna Binding ◽

Rna Binding Proteins ◽

Myogenic Cell ◽

Skeletal Muscle Regeneration ◽

Cell Fate Decisions

ABSTRACTRNA-binding proteins (RBPs) are essential for skeletal muscle regeneration and RBP dysfunction causes muscle degeneration and neuromuscular disease. How ubiquitously expressed RBPs orchestrate complex tissue regeneration and direct cell fate decisions in skeletal muscle remains poorly understood. Single cell RNA-sequencing of regenerating skeletal muscle reveals that RBP expression, including numerous neuromuscular disease-associated RBPs, is temporally regulated in skeletal muscle stem cells and correlates to stages of myogenic differentiation. By combining machine learning with RBP engagement scoring, we discover that the neuromuscular disease associated RBP Hnrnpa2b1 is a differentiation-specifying regulator of myogenesis controlling myogenic cell fate transitions during terminal differentiation. The timing of RBP expression specifies cell fate transitions by providing a layer of post-transcriptional regulation needed to coordinate stem cell fate decisions during complex tissue regeneration.

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Targeted mRNA Decay by RNA Binding Protein AUF1 Regulates Adult Muscle Stem Cell Fate, Promoting Skeletal Muscle Integrity

Cell Reports ◽

10.1016/j.celrep.2016.06.095 ◽

2016 ◽

Vol 16 (5) ◽

pp. 1379-1390 ◽

Cited By ~ 11

Author(s):

Devon M. Chenette ◽

Adam B. Cadwallader ◽

Tiffany L. Antwine ◽

Lauren C. Larkin ◽

Jinhua Wang ◽

...

Keyword(s):

Skeletal Muscle ◽

Stem Cell ◽

Cell Fate ◽

Mrna Decay ◽

Rna Binding ◽

Binding Protein ◽

Rna Binding Protein ◽

Muscle Stem Cell ◽

Stem Cell Fate ◽

Adult Muscle

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Xin, an actin binding protein, is expressed within muscle satellite cells and newly regenerated skeletal muscle fibers

AJP Cell Physiology ◽

10.1152/ajpcell.00124.2007 ◽

2007 ◽

Vol 293 (5) ◽

pp. C1636-C1644 ◽

Cited By ~ 29

Author(s):

Thomas J. Hawke ◽

Daniel J. Atkinson ◽

Shane B. Kanatous ◽

Peter F. M. Van der Ven ◽

Sean C. Goetsch ◽

...

Keyword(s):

Skeletal Muscle ◽

Satellite Cell ◽

Satellite Cells ◽

Myogenic Differentiation ◽

Binding Protein ◽

Skeletal Muscle Regeneration ◽

Actin Binding ◽

Skeletal Muscle Myosin ◽

Muscle Satellite Cells ◽

Actin Binding Protein

Xin is a muscle-specific actin binding protein of which its role and regulation within skeletal muscle is not well understood. Here we demonstrate that Xin mRNA is robustly upregulated (>16-fold) within 12 h of skeletal muscle injury and is localized to the muscle satellite cell population. RT-PCR confirmed the expression pattern of Xin during regeneration, as well as within primary muscle myoblast cultures, but not other known stem cell populations. Immunohistochemical staining of single myofibers demonstrate Xin expression colocalized with the satellite cell marker Syndecan-4 further supporting the mRNA expression of Xin in satellite cells. In situ hybridization of regenerating muscle 5–7 days postinjury illustrates Xin expression within newly regenerated myofibers. Promoter-reporter assays demonstrate that known myogenic transcription factors [myocyte enhancer factor-2 (MEF2), myogenic differentiation-1 (MyoD), and myogenic factor-5 (Myf-5)] transactivate Xin promoter constructs supporting the muscle-specific expression of Xin. To determine the role of Xin within muscle precursor cells, proliferation, migration, and differentiation analysis using Xin, short hairpin RNA (shRNA) were undertaken in C2C12 myoblasts. Reducing endogenous Xin expression resulted in a 26% increase ( P < 0.05) in cell proliferation and a 20% increase ( P < 0.05) in myoblast migratory capacity. Skeletal muscle myosin heavy chain protein levels were increased ( P < 0.05) with Xin shRNA administration; however, this was not accompanied by changes in myoglobin protein (another marker of differentiation) nor overt morphological differences relative to differentiating control cells. Taken together, the present findings support the hypothesis that Xin is expressed within muscle satellite cells during skeletal muscle regeneration and is involved in the regulation of myoblast function.

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The LIM domain protein nTRIP6 modulates the dynamics of myogenic differentiation

Scientific Reports ◽

10.1038/s41598-021-92331-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Tannaz Norizadeh Abbariki ◽

Zita Gonda ◽

Denise Kemler ◽

Pavel Urbanek ◽

Tabea Wagner ◽

...

Keyword(s):

Skeletal Muscle ◽

Satellite Cells ◽

Muscle Regeneration ◽

Myogenic Differentiation ◽

Skeletal Muscle Regeneration ◽

Temporal Control ◽

Lim Domain ◽

Lim Domain Protein ◽

Domain Protein

AbstractThe process of myogenesis which operates during skeletal muscle regeneration involves the activation of muscle stem cells, the so-called satellite cells. These then give rise to proliferating progenitors, the myoblasts which subsequently exit the cell cycle and differentiate into committed precursors, the myocytes. Ultimately, the fusion of myocytes leads to myofiber formation. Here we reveal a role for the transcriptional co-regulator nTRIP6, the nuclear isoform of the LIM-domain protein TRIP6, in the temporal control of myogenesis. In an in vitro model of myogenesis, the expression of nTRIP6 is transiently up-regulated at the transition between proliferation and differentiation, whereas that of the cytosolic isoform TRIP6 is not altered. Selectively blocking nTRIP6 function results in accelerated early differentiation followed by deregulated late differentiation and fusion. Thus, the transient increase in nTRIP6 expression appears to prevent premature differentiation. Accordingly, knocking out the Trip6 gene in satellite cells leads to deregulated skeletal muscle regeneration dynamics in the mouse. Thus, dynamic changes in nTRIP6 expression contributes to the temporal control of myogenesis.

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Tumor Necrosis Factor Alpha Regulates Skeletal Myogenesis by Inhibiting SP1 Interaction with cis-Acting Regulatory Elements within the Fbxl2 Gene Promoter

Molecular and Cellular Biology ◽

10.1128/mcb.00040-20 ◽

2020 ◽

Vol 40 (12) ◽

Author(s):

Michael E. O’Brien ◽

James Londino ◽

Marcus McGinnis ◽

Nathaniel Weathington ◽

Jessica Adair ◽

...

Keyword(s):

Cell Cycle ◽

Skeletal Muscle ◽

Muscle Regeneration ◽

Cell Cycle Progression ◽

Myogenic Differentiation ◽

Core Promoter ◽

Skeletal Muscle Regeneration ◽

Skeletal Myogenesis ◽

Necrosis Factor Alpha ◽

Tnf Α

ABSTRACT FBXL2 is an important ubiquitin E3 ligase component that modulates inflammatory signaling and cell cycle progression, but its molecular regulation is largely unknown. Here, we show that tumor necrosis factor alpha (TNF-α), a critical cytokine linked to the inflammatory response during skeletal muscle regeneration, suppressed Fbxl2 mRNA expression in C2C12 myoblasts and triggered significant alterations in cell cycle, metabolic, and protein translation processes. Gene silencing of Fbxl2 in skeletal myoblasts resulted in increased proliferative responses characterized by activation of mitogen-activated protein (MAP) kinases and nuclear factor kappa B and decreased myogenic differentiation, as reflected by reduced expression of myogenin and impaired myotube formation. TNF-α did not destabilize the Fbxl2 transcript (half-life [t1/2], ∼10 h) but inhibited SP1 transactivation of its core promoter, localized to bp −160 to +42 within the proximal 5′ flanking region of the Fbxl2 gene. Chromatin immunoprecipitation and gel shift studies indicated that SP1 interacted with the Fbxl2 promoter during cellular differentiation, an effect that was less pronounced during proliferation or after TNF-α exposure. TNF-α, via activation of JNK, mediated phosphorylation of SP1 that impaired its binding to the Fbxl2 promoter, resulting in reduced transcriptional activity. The results suggest that SP1 transcriptional activation of Fbxl2 is required for skeletal muscle differentiation, a process that is interrupted by a key proinflammatory myopathic cytokine. IMPORTANCE Skeletal muscle regeneration and repair involve the recruitment and proliferation of resident satellite cells that exit the cell cycle during the process of myogenic differentiation to form myofibers. We demonstrate that the ubiquitin E3 ligase subunit FBXL2 is essential for skeletal myogenesis through its important effects on cell cycle progression and cell proliferative signaling. Further, we characterize a new mechanism whereby sustained stimulation by a major proinflammatory cytokine, TNF-α, regulates skeletal myogenesis by inhibiting the interaction of SP1 with the Fbxl2 core promoter in proliferating myoblasts. Our findings contribute to the understanding of skeletal muscle regeneration through the identification of Fbxl2 as both a critical regulator of myogenic proliferative processes and a susceptible gene target during inflammatory stimulation by TNF-α in skeletal muscle. Modulation of Fbxl2 activity may have relevance to disorders of muscle wasting associated with sustained proinflammatory signaling.

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Conditional Deletion of Dicer in Adult Mice Impairs Skeletal Muscle Regeneration

International Journal of Molecular Sciences ◽

10.3390/ijms20225686 ◽

2019 ◽

Vol 20 (22) ◽

pp. 5686 ◽

Cited By ~ 2

Author(s):

Satoshi Oikawa ◽

Minjung Lee ◽

Takayuki Akimoto

Keyword(s):

Skeletal Muscle ◽

Muscle Regeneration ◽

Myogenic Differentiation ◽

Tibialis Anterior Muscle ◽

Critical Factor ◽

Skeletal Muscle Regeneration ◽

Small Noncoding Rnas ◽

Adult Mice

Skeletal muscle has a remarkable regenerative capacity, which is orchestrated by multiple processes, including the proliferation, fusion, and differentiation of the resident stem cells in muscle. MicroRNAs (miRNAs) are small noncoding RNAs that mediate the translational repression or degradation of mRNA to regulate diverse biological functions. Previous studies have suggested that several miRNAs play important roles in myoblast proliferation and differentiation in vitro. However, their potential roles in skeletal muscle regeneration in vivo have not been fully established. In this study, we generated a mouse in which the Dicer gene, which encodes an enzyme essential in miRNA processing, was knocked out in a tamoxifen-inducible way (iDicer KO mouse) and determined its regenerative potential after cardiotoxin-induced acute muscle injury. Dicer mRNA expression was significantly reduced in the tibialis anterior muscle of the iDicer KO mice, whereas the expression of muscle-enriched miRNAs was only slightly reduced in the Dicer-deficient muscles. After cardiotoxin injection, the iDicer KO mice showed impaired muscle regeneration. We also demonstrated that the number of PAX7+ cells, cell proliferation, and the myogenic differentiation capacity of the primary myoblasts did not differ between the wild-type and the iDicer KO mice. Taken together, these data demonstrate that Dicer is a critical factor for muscle regeneration in vivo.

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HOTAIRM1 regulates neuronal differentiation by modulating NEUROGENIN 2 and the downstream neurogenic cascade

Cell Death and Disease ◽

10.1038/s41419-020-02738-w ◽

2020 ◽

Vol 11 (7) ◽

Cited By ~ 1

Author(s):

Jessica Rea ◽

Valentina Menci ◽

Paolo Tollis ◽

Tiziana Santini ◽

Alexandros Armaos ◽

...

Keyword(s):

Neuronal Differentiation ◽

Cell Fate ◽

Long Noncoding Rna ◽

Noncoding Rna ◽

Regulatory Networks ◽

Rna Binding ◽

Rna Binding Proteins ◽

Regulatory Cascade ◽

Expression Control ◽

Gene Expression Control

Abstract Neuronal differentiation is a timely and spatially regulated process, relying on precisely orchestrated gene expression control. The sequential activation/repression of genes driving cell fate specification is achieved by complex regulatory networks, where transcription factors and noncoding RNAs work in a coordinated manner. Herein, we identify the long noncoding RNA HOTAIRM1 (HOXA Transcript Antisense RNA, Myeloid-Specific 1) as a new player in neuronal differentiation. We demonstrate that the neuronal-enriched HOTAIRM1 isoform epigenetically controls the expression of the proneural transcription factor NEUROGENIN 2 that is key to neuronal fate commitment and critical for brain development. We also show that HOTAIRM1 activity impacts on NEUROGENIN 2 downstream regulatory cascade, thus contributing to the achievement of proper neuronal differentiation timing. Finally, we identify the RNA-binding proteins HNRNPK and FUS as regulators of HOTAIRM1 biogenesis and metabolism. Our findings uncover a new regulatory layer underlying NEUROGENIN 2 transitory expression in neuronal differentiation and reveal a previously unidentified function for the neuronal-induced long noncoding RNA HOTAIRM1.

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Tenogenic Contribution to Skeletal Muscle Regeneration: The Secretome of Scleraxis Overexpressing Mesenchymal Stem Cells Enhances Myogenic Differentiation In Vitro

International Journal of Molecular Sciences ◽

10.3390/ijms21061965 ◽

2020 ◽

Vol 21 (6) ◽

pp. 1965

Author(s):

Maximilian Strenzke ◽

Paolo Alberton ◽

Attila Aszodi ◽

Denitsa Docheva ◽

Elisabeth Haas ◽

...

Keyword(s):

Skeletal Muscle ◽

Muscle Regeneration ◽

Skeletal Muscles ◽

Myogenic Differentiation ◽

Muscular Contraction ◽

Myoblast Fusion ◽

Skeletal Muscle Regeneration ◽

Potential Candidate ◽

Musculoskeletal Tissue

Integrity of the musculoskeletal system is essential for the transfer of muscular contraction force to the associated bones. Tendons and skeletal muscles intertwine, but on a cellular level, the myotendinous junctions (MTJs) display a sharp transition zone with a highly specific molecular adaption. The function of MTJs could go beyond a mere structural role and might include homeostasis of this musculoskeletal tissue compound, thus also being involved in skeletal muscle regeneration. Repair processes recapitulate several developmental mechanisms, and as myotendinous interaction does occur already during development, MTJs could likewise contribute to muscle regeneration. Recent studies identified tendon-related, scleraxis-expressing cells that reside in close proximity to the MTJs and the muscle belly. As the muscle-specific function of these scleraxis positive cells is unknown, we compared the influence of two immortalized mesenchymal stem cell (MSC) lines—differing only by the overexpression of scleraxis—on myoblasts morphology, metabolism, migration, fusion, and alignment. Our results revealed a significant increase in myoblast fusion and metabolic activity when exposed to the secretome derived from scleraxis-overexpressing MSCs. However, we found no significant changes in myoblast migration and myofiber alignment. Further analysis of differentially expressed genes between native MSCs and scleraxis-overexpressing MSCs by RNA sequencing unraveled potential candidate genes, i.e., extracellular matrix (ECM) proteins, transmembrane receptors, or proteases that might enhance myoblast fusion. Our results suggest that musculotendinous interaction is essential for the development and healing of skeletal muscles.

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Severe muscle wasting and denervation in mice lacking the RNA-binding protein ZFP106

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1608423113 ◽

2016 ◽

Vol 113 (31) ◽

pp. E4494-E4503 ◽

Cited By ~ 16

Author(s):

Douglas M. Anderson ◽

Jessica Cannavino ◽

Hui Li ◽

Kelly M. Anderson ◽

Benjamin R. Nelson ◽

...

Keyword(s):

Skeletal Muscle ◽

Motor Neurons ◽

Knockout Mice ◽

Muscle Wasting ◽

Rna Binding ◽

Neuromuscular Junctions ◽

Binding Protein ◽

Rna Binding Protein ◽

Binding Motif ◽

Nerve Muscle

Innervation of skeletal muscle by motor neurons occurs through the neuromuscular junction, a cholinergic synapse essential for normal muscle growth and function. Defects in nerve–muscle signaling cause a variety of neuromuscular disorders with features of ataxia, paralysis, skeletal muscle wasting, and degeneration. Here we show that the nuclear zinc finger protein ZFP106 is highly enriched in skeletal muscle and is required for postnatal maintenance of myofiber innervation by motor neurons. Genetic disruption of Zfp106 in mice results in progressive ataxia and hindlimb paralysis associated with motor neuron degeneration, severe muscle wasting, and premature death by 6 mo of age. We show that ZFP106 is an RNA-binding protein that associates with the core splicing factor RNA binding motif protein 39 (RBM39) and localizes to nuclear speckles adjacent to spliceosomes. Upon inhibition of pre-mRNA synthesis, ZFP106 translocates with other splicing factors to the nucleolus. Muscle and spinal cord of Zfp106 knockout mice displayed a gene expression signature of neuromuscular degeneration. Strikingly, altered splicing of the Nogo (Rtn4) gene locus in skeletal muscle of Zfp106 knockout mice resulted in ectopic expression of NOGO-A, the neurite outgrowth factor that inhibits nerve regeneration and destabilizes neuromuscular junctions. These findings reveal a central role for Zfp106 in the maintenance of nerve–muscle signaling, and highlight the involvement of aberrant RNA processing in neuromuscular disease pathogenesis.

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