Characterization of contraction-induced IL-6 up-regulation using contractile C2C12 myotubes

Farmawati, Arta; Kitajima, Yasuo; Nedachi, Taku; Sato, Masaaki; Kanzaki, Makoto; Nagatomi, Ryoichi

doi:10.1507/endocrj.ej12-0316

Cited by 36 publications

(39 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Interleukin-6 is known to be an important contraction-regulated myokine released by muscle cells in response to exercise in vivo (Keller et al 2001;Febbraio et al 2004) and in vitro (Scheler et al 2013;Evers-van Gogh et al 2015;Feng et al 2015). In accordance with previous data, increased release of IL-6 was observed in myotubes exposed to EPS (Lambernd et al 2012;Farmawati et al 2013;Scheler et al 2013;Christensen et al 2015;Feng et al 2015), which indicates that in addition to the hypertrophy of muscle cells, our in vitro exercise model recapitulates another important exercise-induced physiological event. Even though the primary aim of the present work was to demonstrate that the in vitro model induces the occurrence of a major physiological end-point to resistance exercise (morphological enlargement of muscle cells), we provided additional information about selected markers representing a snapshot of the hypertrophic process.…”

Section: Discussionsupporting

confidence: 93%

Electrical pulse stimulation: an in vitro exercise model for the induction of human skeletal muscle cell hypertrophy. A proof‐of‐concept study

Tarum

Folkesson

Atherton

et al. 2017

Experimental Physiology

View full text Add to dashboard Cite

What is the central question of this study? Is electrical pulse stimulation (EPS) an in vitro exercise model able to elicit the hypertrophy of human muscle cells? What is the main finding and its importance? The addition of a restitution period of 8 h after EPS induces the enlargement of human muscle cells, a major physiological end-point to resistance exercise. This is supported by downregulation of myostatin, a negative regulator of muscle mass, and increased phosphorylated mTOR and 4E-BP1, key factors in the growth cascade. This proof-of-concept study provides a model of physiologically mediated muscle growth, which will be the basis for future studies aiming to depict molecular events governing the hypertrophy of human muscle cells. Electrical pulse stimulation (EPS) of muscle cells has previously been used as an in vitro exercise model. The present study aimed to establish an EPS protocol promoting the hypertrophy of human muscle cells, which represents a major physiological end-point to resistance exercise in humans. We hypothesized that adding a resting period after EPS would be crucial for the occurrence of the morphological change. Myoblasts obtained from human muscle biopsies (n = 5) were differentiated into multinucleated myotubes and exposed to 8 h of EPS consisting of 2 ms pulses at 12 V, with a frequency of 1 Hz. Myotube size was assessed using immunohistochemistry immediately, 4 and 8 h after completed EPS. Gene expression and phosphorylation status of selected markers of hypertrophy were assessed using RT-PCR and Western blotting, respectively. Release of the myokine interleukin-6 in culture medium was measured using enzyme-linked immunosorbent assay. We demonstrated a significant increase (31 ± 14%; P = 0.03) in the size of myotubes when EPS was followed by an 8 h resting period, but not immediately or 4 h after completion of EPS. The response was supported by downregulation (P = 0.04) of the gene expression of myostatin, a negative regulator of muscle mass, and an increase in phosphorylated mTOR (P = 0.03) and 4E-BP1 (P = 0.01), which are important factors in the cellular growth signalling cascade. The present work demonstrates that EPS is an in vitro exercise model promoting the hypertrophy of human muscle cells, recapitulating a major physiological end-point to resistance exercise in human skeletal muscle.

show abstract

Section: Discussionsupporting

confidence: 93%

Electrical pulse stimulation: an in vitro exercise model for the induction of human skeletal muscle cell hypertrophy. A proof‐of‐concept study

Tarum

Folkesson

Atherton

et al. 2017

Experimental Physiology

View full text Add to dashboard Cite

show abstract

“…To our knowledge this is the first study utilizing a combination of these techniques. Previously, application of EPS has been shown to stimulate sarcomere assembly in C2C12 cells (Fujita et al, 2007;Park et al, 2008) and to trigger various metabolic and transcriptional events typically associated with exercise (Farmawati et al, 2013;Marotta et al, 2004;Nedachi et al, 2008;Nedachi et al, 2009;Wang et al, 2010;Wehrle et al, 1994). Here, we demonstrate that the Xin-aciculin complex, as revealed by BiFC, is localized at FLNc-containing sites during EPS-induced muscle remodeling and seems to be involved in myofibril repair.…”

Section: Functional Implications Of Aciculin-containing Protein Complmentioning

confidence: 52%

Aciculin interacts with filamin C and Xin and is essential for myofibril assembly, remodeling and maintenance

Molt

Bührdel

Yakovlev

et al. 2014

Journal of Cell Science

View full text Add to dashboard Cite

Filamin C (FLNc) and Xin actin-binding repeat-containing proteins (XIRPs) are multi-adapter proteins mainly expressed in cardiac and skeletal muscles that play important roles in the assembly and repair of myofibrils and their attachment to the membrane. We identified the dystrophin-binding protein aciculin (PGM5), as a novel interaction partner of FLNc and Xin. All three proteins colocalize at intercalated discs of cardiac muscle and myotendinous junctions of skeletal muscle, while FLNc and aciculin also colocalize in mature Z-discs. Bimolecular fluorescence complementation experiments in developing cultured mammalian skeletal muscle cells demonstrate that Xin and aciculin also interact in FLNc-containing immature myofibrils and areas of myofibrillar remodeling and repair induced by electrical pulse stimulation (EPS). FRAP experiments show that aciculin is a highly dynamic and mobile protein. Aciculin knockdown in myotubes leads to failure in myofibril assembly, alignment and membrane attachment, and massive reduction in myofibril number. A highly similar phenotype was found upon depletion of aciculin in zebrafish embryos. Our results point to a thus far unappreciated but essential function of aciculin in myofibril formation, maintenance and remodeling.

show abstract

“…; Farmawati et al . ). Fully differentiated C2C12 myotubes were subjected to EPS, and conditioned media and total RNA were collected for the Bio‐Plex assay and RT‐PCR analyses, respectively.…”

Section: Resultsmentioning

confidence: 97%

Exercise‐evoked intramuscular neutrophil‐endothelial interactions support muscle performance and GLUT4 translocation: a mouse gnawing model study

Chaweewannakorn

Nyasha

Chen

et al. 2019

The Journal of Physiology

Self Cite

View full text Add to dashboard Cite

Key pointsr Fractalkine receptor antagonist inhibited neutrophil recruitment to masseter muscles and exacerbated fatigability during masticatory activity.r Fractalkine-mediated neutrophil recruitment is required for both upregulation of myokines (CXCL1, interleukin-6) and enhanced GLUT4 translocation in response to masticatory activity.r Fractalkine and intercellular adhesion molecule-1 expression in endothelial cells increased in response to masticatory activity.r In vitro experiments demonstrated that contracting myotubes lack the ability to upregulate fractalkine but revealed that endothelial fractalkine upregulation is induced using a conditioned medium of contracting myotubes.Abstract Physical exercise stimulates neutrophil recruitment within working skeletal muscle, although its underlying mechanisms remain ill-defined. By employing a masticatory behaviour (gnawing) model, we demonstrate the importance of intramuscular paracrine and autocrine systems that are triggered by muscle contractile activity and reliant upon fractalkine/CX3CL1-mediated signals. These signals were revealed to be required for achieving proper GLUT4 translocation and glucose uptake to meet the glucose demands for fatigue alleviation. Specifically, fractalkine expression and neutrophil recruitment both increased in the masseter muscle tissues upon masticatory activity. Importantly, a fractalkine antagonist inhibited neutrophil accumulation and exacerbated fatigability during masticatory activity. We found that fractalkine-dependent neutrophil recruitment is required for both upregulation of myokines (i.e. CXCL1 and interleukin-6) and enhanced GLUT4 translocation in response to Chayanit Chaweewannakorn, DDS, PhD, obtained her doctoral degree in dental science from Tohoku University and her doctor of dental surgery degree from Chulalongkorn University. During her doctoral degree, she collaborated on publications on the skeletal muscle biology in response to exercise, especially the changes in immune components. Her major field interests are in the masticatory muscle responses related to temporomandibular disease and orofacial pain. Currently, she is a dentist and lecturer at C. Chaweewannakorn and others J Physiol 598.1 gnawing activity. Immunofluorescence analysis of masseter muscles demonstrated that fractalkine and intercellular adhesion molecule-1 expression are both upregulated in endothelial cells but not in myofibres. The in vitro exercise model further revealed that contractile activity failed to stimulate fractalkine upregulation in myotubes, implying that fractalkine is not a myokine (myofibre-derived factor). Nevertheless, endothelial fractalkine expression was markedly stimulated by a conditioned medium from the contracting myotubes. Moreover, intercellular adhesion molecule-1, a key adhesion molecule for neutrophils, was upregulated in endothelial cells by fractalkine. Taken together, our findings strongly suggest that endothelial fractalkine serves as a key factor for organizing a physiologically beneficial intramuscular mic...

show abstract

Characterization of contraction-induced IL-6 up-regulation using contractile C2C12 myotubes

Cited by 36 publications

References 46 publications

Electrical pulse stimulation: an in vitro exercise model for the induction of human skeletal muscle cell hypertrophy. A proof‐of‐concept study

Electrical pulse stimulation: an in vitro exercise model for the induction of human skeletal muscle cell hypertrophy. A proof‐of‐concept study

Aciculin interacts with filamin C and Xin and is essential for myofibril assembly, remodeling and maintenance

Exercise‐evoked intramuscular neutrophil‐endothelial interactions support muscle performance and GLUT4 translocation: a mouse gnawing model study

Contact Info

Product

Resources

About