Limits...
Type 1 interferons inhibit myotube formation independently of upregulation of interferon-stimulated gene 15.

Franzi S, Salajegheh M, Nazareno R, Greenberg SA - PLoS ONE (2013)

Bottom Line: Type 1 IFNs, especially IFN-beta, increased ISG15 expression in C2C12 cells and impaired myotube formation.Silencing of ISG15 resulted in knockdown of ISG15 protein, but without phenotypic rescue of myotube formation.IFN-beta affects myoblast differentiation ability and myotube morphology in vitro.These studies provide evidence that ISG15, which is highly upregulated in dermatomyositis muscle, does not appear to play a key role in IFN-beta-mediated C2C12 myoblast cell fusion.

View Article: PubMed Central - PubMed

Affiliation: Children's Hospital Informatics Program, Boston Children's Hospital, Boston, Massachusetts, USA.

ABSTRACT

Introduction: Type 1 interferon (IFN)-inducible genes and their inducible products are upregulated in dermatomyositis muscle. Of these, IFN-stimulated gene 15 (ISG15) is one of the most upregulated, suggesting its possible involvement in the pathogenesis of this disease. To test this postulate, we developed a model of type 1 IFN mediated myotube toxicity and assessed whether or not downregulation of ISG15 expression prevents this toxicity.

Methods: Mouse myoblasts (C2C12 cell line) were cultured in the presence of type 1 or type 2 IFNs and ISG15 expression assessed by microarray analysis. The morphology of newly formed myotubes was assessed by measuring their length, diameter, and area on micrographs using imaging software. ISG15 expression was silenced through transfection with small interference RNA.

Results: Type 1 IFNs, especially IFN-beta, increased ISG15 expression in C2C12 cells and impaired myotube formation. Silencing of ISG15 resulted in knockdown of ISG15 protein, but without phenotypic rescue of myotube formation.

Discussion: IFN-beta affects myoblast differentiation ability and myotube morphology in vitro.These studies provide evidence that ISG15, which is highly upregulated in dermatomyositis muscle, does not appear to play a key role in IFN-beta-mediated C2C12 myoblast cell fusion.

Show MeSH

Related in: MedlinePlus

Effects of type 1 IFNs on mouse C2C12 and human muscle cells.(A) IFN-β results in sustained marked expression of ISG15 (196-fold increased at Day 7). (B) Sustained toxicity of IFN-β on myotube area. (C–E) Dose-dependent effects of IFN-β 10 U/ml and 100 U/ml on myotubes. (C) Dose-dependent reduction in numbers and lengths of C2C12 myotubes at 48 h and 72 h. Arrows indicate myotubes. (D) Dose-dependent reduction in C2C12 myotube length, diameter, and area at 72h. (E) Dose-dependent effect of IFN-β on 72 h human skeletal muscle with marked inhibition of myotube formation at 100 U/ml.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3672209&req=5

pone-0065362-g001: Effects of type 1 IFNs on mouse C2C12 and human muscle cells.(A) IFN-β results in sustained marked expression of ISG15 (196-fold increased at Day 7). (B) Sustained toxicity of IFN-β on myotube area. (C–E) Dose-dependent effects of IFN-β 10 U/ml and 100 U/ml on myotubes. (C) Dose-dependent reduction in numbers and lengths of C2C12 myotubes at 48 h and 72 h. Arrows indicate myotubes. (D) Dose-dependent reduction in C2C12 myotube length, diameter, and area at 72h. (E) Dose-dependent effect of IFN-β on 72 h human skeletal muscle with marked inhibition of myotube formation at 100 U/ml.

Mentions: In previously published studies, ISG15 was upregulated 194-fold in human DM muscle biopsy samples [5]. We studied a muscle cell culture line, C2C12 cells, stimulating them with IFN-α, IFN-β, and IFN-γ for 7 days and assessed global transcriptional responses at Day 4 and Day 7 (manuscript in preparation). ISG15 gene expression was upregulated on Day 4 114-fold in response to IFN-α, 191-fold in response to IFN-β, and 11-fold in response to IFN-γ (Figure 1A). ISG15’s marked upregulation by IFN-β was sustained at Day 7 (196-fold) in contrast to its response to IFN-α that had diminished compared to Day 4 (30-fold).


Type 1 interferons inhibit myotube formation independently of upregulation of interferon-stimulated gene 15.

Franzi S, Salajegheh M, Nazareno R, Greenberg SA - PLoS ONE (2013)

Effects of type 1 IFNs on mouse C2C12 and human muscle cells.(A) IFN-β results in sustained marked expression of ISG15 (196-fold increased at Day 7). (B) Sustained toxicity of IFN-β on myotube area. (C–E) Dose-dependent effects of IFN-β 10 U/ml and 100 U/ml on myotubes. (C) Dose-dependent reduction in numbers and lengths of C2C12 myotubes at 48 h and 72 h. Arrows indicate myotubes. (D) Dose-dependent reduction in C2C12 myotube length, diameter, and area at 72h. (E) Dose-dependent effect of IFN-β on 72 h human skeletal muscle with marked inhibition of myotube formation at 100 U/ml.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3672209&req=5

pone-0065362-g001: Effects of type 1 IFNs on mouse C2C12 and human muscle cells.(A) IFN-β results in sustained marked expression of ISG15 (196-fold increased at Day 7). (B) Sustained toxicity of IFN-β on myotube area. (C–E) Dose-dependent effects of IFN-β 10 U/ml and 100 U/ml on myotubes. (C) Dose-dependent reduction in numbers and lengths of C2C12 myotubes at 48 h and 72 h. Arrows indicate myotubes. (D) Dose-dependent reduction in C2C12 myotube length, diameter, and area at 72h. (E) Dose-dependent effect of IFN-β on 72 h human skeletal muscle with marked inhibition of myotube formation at 100 U/ml.
Mentions: In previously published studies, ISG15 was upregulated 194-fold in human DM muscle biopsy samples [5]. We studied a muscle cell culture line, C2C12 cells, stimulating them with IFN-α, IFN-β, and IFN-γ for 7 days and assessed global transcriptional responses at Day 4 and Day 7 (manuscript in preparation). ISG15 gene expression was upregulated on Day 4 114-fold in response to IFN-α, 191-fold in response to IFN-β, and 11-fold in response to IFN-γ (Figure 1A). ISG15’s marked upregulation by IFN-β was sustained at Day 7 (196-fold) in contrast to its response to IFN-α that had diminished compared to Day 4 (30-fold).

Bottom Line: Type 1 IFNs, especially IFN-beta, increased ISG15 expression in C2C12 cells and impaired myotube formation.Silencing of ISG15 resulted in knockdown of ISG15 protein, but without phenotypic rescue of myotube formation.IFN-beta affects myoblast differentiation ability and myotube morphology in vitro.These studies provide evidence that ISG15, which is highly upregulated in dermatomyositis muscle, does not appear to play a key role in IFN-beta-mediated C2C12 myoblast cell fusion.

View Article: PubMed Central - PubMed

Affiliation: Children's Hospital Informatics Program, Boston Children's Hospital, Boston, Massachusetts, USA.

ABSTRACT

Introduction: Type 1 interferon (IFN)-inducible genes and their inducible products are upregulated in dermatomyositis muscle. Of these, IFN-stimulated gene 15 (ISG15) is one of the most upregulated, suggesting its possible involvement in the pathogenesis of this disease. To test this postulate, we developed a model of type 1 IFN mediated myotube toxicity and assessed whether or not downregulation of ISG15 expression prevents this toxicity.

Methods: Mouse myoblasts (C2C12 cell line) were cultured in the presence of type 1 or type 2 IFNs and ISG15 expression assessed by microarray analysis. The morphology of newly formed myotubes was assessed by measuring their length, diameter, and area on micrographs using imaging software. ISG15 expression was silenced through transfection with small interference RNA.

Results: Type 1 IFNs, especially IFN-beta, increased ISG15 expression in C2C12 cells and impaired myotube formation. Silencing of ISG15 resulted in knockdown of ISG15 protein, but without phenotypic rescue of myotube formation.

Discussion: IFN-beta affects myoblast differentiation ability and myotube morphology in vitro.These studies provide evidence that ISG15, which is highly upregulated in dermatomyositis muscle, does not appear to play a key role in IFN-beta-mediated C2C12 myoblast cell fusion.

Show MeSH
Related in: MedlinePlus