Interleukin-15 directly stimulates pro-oxidative gene expression in skeletal muscle in-vitro via a mechanism that requires interleukin-15 receptor alpha

2015 ◽  
Vol 458 (3) ◽  
pp. 614-619 ◽  
Author(s):  
Grant C. O'Connell ◽  
Emidio E. Pistilli
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Receptor Alpha ◽  
Interleukin 15 ◽  
Interleukin 15 Receptor Alpha

Retinoic Acid Receptor Agonists Suppress Muscle Fatty Infiltration in Mice

2021 ◽  
Vol 49 (2) ◽  
pp. 332-339
Author(s):  
Hideyuki Shirasawa ◽  
Noboru Matsumura ◽  
Masaki Yoda ◽  
Kazumasa Okubo ◽  
Masayuki Shimoda ◽  
...  
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Rotator Cuff ◽  
Rotator Cuff Tear ◽  
Gene Expression Analysis ◽  
Retinoic Acid Receptor ◽  
Adipogenic Differentiation ◽  
Fatty Infiltration ◽  
Cuff Tear

Background: The infiltration of fat tissue into skeletal muscle, a condition referred to as muscle fatty infiltration or fatty degeneration, is regarded as an irreversible event that significantly compromises the motor function of skeletal muscle. Purpose: To investigate the effect of retinoic acid receptor (RAR) agonists in suppressing the adipogenic differentiation of fibroadipogenic progenitors (FAPs) in vitro and fatty infiltration after rotator cuff tear in mice. Study Design: Controlled laboratory study. Methods: FAPs isolated from mouse skeletal muscle were cultured in adipogenic differentiation medium in the presence or absence of an RAR agonist. At the end of cell culture, adipogenic differentiation was evaluated by gene expression analysis and oil red O staining. A mouse model of fatty infiltration—which includes the resection of the rotator cuff, removal of the humeral head, and denervation the supraspinatus muscle—was used to induce fatty infiltration in the supraspinatus muscle. The mice were orally or intramuscularly administered with an RAR agonist after the surgery. Muscle fatty infiltration was evaluated by histology and gene expression analysis. Results: RAR agonists effectively inhibited the adipogenic differentiation of FAPs in vitro. Oral and intramuscular administration of RAR agonists suppressed the development of muscle fatty infiltration in the mice after rotator cuff tear. In accordance, we found a significant decrease in the number of intramuscular fat cells and suppressed expression in adipogenic markers. RAR agonists also increased the expression of the transcripts for collagens; however, an accumulation of collagenous tissues was not histologically evident in the present model. Conclusion: Muscle fatty infiltration can be alleviated by RAR agonists through suppressing the adipogenic differentiation of FAPs. The results also suggest that RAR agonists are potential therapeutic agents for treating patients who are at risk of developing muscle fatty infiltration. The consequence of the increased expression of collagen transcripts by RAR agonists needs to be clarified. Clinical Relevance: RAR agonists can be used to prevent the development of muscle fatty infiltration after rotator cuff tear. Nevertheless, further studies are mandatory in a large animal model to examine the safety and efficacy of intramuscular injection of RAR agonists.

scholarly journals Myostatin Promotes Osteoclastogenesis by Regulating Ccdc50 Gene Expression and RANKL-Induced NF-κB and MAPK Pathways

2020 ◽  
Vol 11 ◽  
Author(s):  
Xin Zhi ◽  
Qian Chen ◽  
Shaojun Song ◽  
Zhengrong Gu ◽  
Wenqiang Wei ◽  
...  
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Growth And Development ◽  
Essential Role ◽  
Gene Overexpression ◽  
Promising Candidate ◽  
Mapk Pathways ◽  
Candidate Target ◽  
Type Receptor

Myostatin is a crucial cytokine that is widely present in skeletal muscle and that negatively regulates the growth and development of muscle cells. Recent research has shown that myostatin might play an essential role in bone metabolism. In RAW264.7 cells and bone marrow monocytes (BMMCs), myostatin activates the expression of the II type receptor ActR II B. Here, we report that myostatin significantly promoted RANKL/M-CSF-induced osteoclastogenesis and activated NF-κB and MAPK pathways in vitro via the Ccdc50 gene. Overexpression of myostatin promoted osteoclastogenesis and osteoclastogenesis-related markers including c-Src, MMP9, CTR, CK, and NFATc1. Specifically, myostatin increased the phosphorylation of Smad2, which led to the activation of NF-κB and MAPK pathways to activate osteoclastogenesis. Ccdc50 was identified as a gene whose expression was highly decreased in osteoclastogenesis upon myostatin treatment, and it could inhibit the function of myostatin in osteoclastogenesis by blocking NF-κB and MAPKs pathways. Our study indicates that myostatin is a promising candidate target for inhibiting RANKL-mediated osteoclastogenesis and might participate in therapy for osteoporosis, and that the Ccdc50 gene plays a significant role in the regulatory process.

Integrin signaling's potential for mediating gene expression in hypertrophying skeletal muscle

2000 ◽  
Vol 88 (1) ◽  
pp. 337-343 ◽  
Author(s):  
James A. Carson ◽  
Lei Wei
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Signaling Pathway ◽  
Mechanical Load ◽  
Integrin Signaling ◽  
Mechanical Forces ◽  
Growth Factor Signaling ◽  
Muscle Gene

Overloaded skeletal muscle undergoes dramatic shifts in gene expression, which alter both the phenotype and mass. Molecular biology techniques employing both in vivo and in vitro hypertrophy models have demonstrated that mechanical forces can alter skeletal muscle gene regulation. This review's purpose is to support integrin-mediated signaling as a candidate for mechanical load-induced hypertrophy. Research quantifying components of the integrin-signaling pathway in overloaded skeletal muscle have been integrated with knowledge regarding integrins role during development and cardiac hypertrophy, with the hope of demonstrating the pathway's importance. The role of integrin signaling as an integrator of mechanical forces and growth factor signaling during hypertrophy is discussed. Specific components of integrin signaling, including focal adhesion kinase and low-molecular-weight GTPase Rho are mentioned as downstream targets of this signaling pathway. There is a need for additional mechanistic studies capable of providing a stronger linkage between integrin-mediated signaling and skeletal muscle hypertrophy; however, there appears to be abundant justification for this type of research.

scholarly journals Activation of Utrophin Promoter by Heregulin via theets-related Transcription Factor Complex GA-binding Protein α/β

1999 ◽  
Vol 10 (6) ◽  
pp. 2075-2086 ◽  
Author(s):  
Tejvir S. Khurana ◽  
Alan G. Rosmarin ◽  
Jing Shang ◽  
Thomas O. B. Krag ◽  
Saumya Das ◽  
...  
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Transcription Factors ◽  
Neuromuscular Junction ◽  
Muscle Cell ◽  
Cell Cultures ◽  
Binding Protein ◽  
Duchenne's Muscular Dystrophy ◽  
Ga Binding Protein

Utrophin/dystrophin-related protein is the autosomal homologue of the chromosome X-encoded dystrophin protein. In adult skeletal muscle, utrophin is highly enriched at the neuromuscular junction. However, the molecular mechanisms underlying regulation of utrophin gene expression are yet to be defined. Here we demonstrate that the growth factor heregulin increases de novo utrophin transcription in muscle cell cultures. Using mutant reporter constructs of the utrophin promoter, we define the N-box region of the promoter as critical for heregulin-mediated activation. Using this region of the utrophin promoter for DNA affinity purification, immunoblots, in vitro kinase assays, electrophoretic mobility shift assays, and in vitro expression in cultured muscle cells, we demonstrate thatets-related GA-binding protein α/β transcription factors are activators of the utrophin promoter. Taken together, these results suggest that the GA-binding protein α/β complex of transcription factors binds and activates the utrophin promoter in response to heregulin-activated extracellular signal–regulated kinase in muscle cell cultures. These findings suggest methods for achieving utrophin up-regulation in Duchenne’s muscular dystrophy as well as mechanisms by which neurite-derived growth factors such as heregulin may influence the regulation of utrophin gene expression and subsequent enrichment at the neuromuscular junction of skeletal muscle.

FoxO1 Activation Promotes Proapoptotic Gene Expression In Differentiated Skeletal Muscle In Vitro

2005 ◽  
Vol 37 (Supplement) ◽  
pp. S245
Author(s):  
Thomas J. McLoughlin ◽  
Terry G. Unterman ◽  
Karyn A. Esser
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Proapoptotic Gene

scholarly journals Accelerated Response of the myogenin Gene to Denervation in Mutant Mice Lacking Phosphorylation of Myogenin at Threonine 87

2004 ◽  
Vol 24 (5) ◽  
pp. 1983-1989 ◽  
Author(s):  
Chris S. Blagden ◽  
Larry Fromm ◽  
Steven J. Burden
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Electrical Activity ◽  
Muscle Development ◽  
Mutant Mice ◽  
Threonine Residue ◽  
E Boxes ◽  
Bhlh Proteins

ABSTRACT Gene expression in skeletal muscle is regulated by a family of myogenic basic helix-loop-helix (bHLH) proteins. The binding of these bHLH proteins, notably MyoD and myogenin, to E-boxes in their own regulatory regions is blocked by protein kinase C (PKC)-mediated phosphorylation of a single threonine residue in their basic region. Because electrical stimulation increases PKC activity in skeletal muscle, these data have led to an attractive model suggesting that electrical activity suppresses gene expression by stimulating phosphorylation of this critical threonine residue in myogenic bHLH proteins. We show that electrical activity stimulates phosphorylation of myogenin at threonine 87 (T87) in vivo and that calmodulin-dependent kinase II (CaMKII), as well as PKC, catalyzes this reaction in vitro. We find that phosphorylation of myogenin at T87 is dispensable for skeletal muscle development. We show, however, that the decrease in myogenin (myg) expression following innervation is delayed and that the increase in expression following denervation is accelerated in mutant mice lacking phosphorylation of myogenin at T87. These data indicate that two distinct innervation-dependent mechanisms restrain myogenin activity: an inactivation mechanism mediated by phosphorylation of myogenin at T87, and a second, novel regulatory mechanism that regulates myg gene activity independently of T87 phosphorylation.

scholarly journals Macrophage- and Dendritic-Cell-Derived Interleukin-15 Receptor Alpha Supports Homeostasis of Distinct CD8+ T Cell Subsets

Immunity ◽  
2009 ◽  
Vol 31 (5) ◽  
pp. 811-822 ◽  
Author(s):  
Erwan Mortier ◽  
Rommel Advincula ◽  
Leesun Kim ◽  
Stephen Chmura ◽  
Julio Barrera ◽  
...  
Keyword(s):  
T Cell ◽  
Dendritic Cell ◽  
Cd8 T Cell ◽  
T Cell Subsets ◽  
Receptor Alpha ◽  
Interleukin 15 ◽  
Interleukin 15 Receptor Alpha
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