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TNF-α and IGF1 modify the microRNA signature in skeletal muscle cell differentiation.

Meyer SU, Thirion C, Polesskaya A, Bauersachs S, Kaiser S, Krause S, Pfaffl MW - Cell Commun. Signal (2015)

Bottom Line: Results reveal that i) TNF-α and IGF1 regulate miRNA expression during skeletal muscle cell differentiation in vitro, ii) microRNA targets can mediate the negative effect of TNF-α on fusion capacity of skeletal myoblasts by targeting genes associated with axon guidance, MAPK signalling, focal adhesion, and neurotrophin signalling pathway, iii) inhibition of miR-155 in combination with overexpression of miR-503 partially abrogates the inhibitory effect of TNF-α on myotube formation, and iv) MAPK/ERK inhibition might participate in modulating the effect of TNF-α and IGF1 on miRNA abundance.The inhibitory effects of TNF-α or the growth promoting effects of IGF1 on skeletal muscle differentiation include the deregulation of known muscle-regulatory miRNAs as well as miRNAs which have not yet been associated with skeletal muscle differentiation or response to TNF-α or IGF1.This study indicates that miRNAs are mediators of the inhibitory effect of TNF-α on myoblast differentiation.

View Article: PubMed Central - PubMed

Affiliation: Physiology Weihenstephan, ZIEL Research Center for Nutrition and Food Sciences, Technische Universität München, Weihenstephaner Berg 3, D-85354, Freising, Germany. meyers@wzw.tum.de.

ABSTRACT

Background: Elevated levels of the inflammatory cytokine TNF-α are common in chronic diseases or inherited or degenerative muscle disorders and can lead to muscle wasting. By contrast, IGF1 has a growth promoting effect on skeletal muscle. The molecular mechanisms mediating the effect of TNF-α and IGF1 on muscle cell differentiation are not completely understood. Muscle cell proliferation and differentiation are regulated by microRNAs (miRNAs) which play a dominant role in this process. This study aims at elucidating how TNF-α or IGF1 regulate microRNA expression to affect myoblast differentiation and myotube formation.

Results: In this study, we analyzed the impact of TNF-α or IGF1 treatment on miRNA expression in myogenic cells. Results reveal that i) TNF-α and IGF1 regulate miRNA expression during skeletal muscle cell differentiation in vitro, ii) microRNA targets can mediate the negative effect of TNF-α on fusion capacity of skeletal myoblasts by targeting genes associated with axon guidance, MAPK signalling, focal adhesion, and neurotrophin signalling pathway, iii) inhibition of miR-155 in combination with overexpression of miR-503 partially abrogates the inhibitory effect of TNF-α on myotube formation, and iv) MAPK/ERK inhibition might participate in modulating the effect of TNF-α and IGF1 on miRNA abundance.

Conclusions: The inhibitory effects of TNF-α or the growth promoting effects of IGF1 on skeletal muscle differentiation include the deregulation of known muscle-regulatory miRNAs as well as miRNAs which have not yet been associated with skeletal muscle differentiation or response to TNF-α or IGF1. This study indicates that miRNAs are mediators of the inhibitory effect of TNF-α on myoblast differentiation. We show that intervention at the miRNA level can ameliorate the negative effect of TNF-α by promoting myoblast differentiation. Moreover, we cautiously suggest that TNF-α or IGF1 modulate the miRNA biogenesis of some miRNAs via MAPK/ERK signalling. Finally, this study identifies indicative biomarkers of myoblast differentiation and cytokine influence and points to novel RNA targets.

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Predicted targets of murine miRNAs associated with myogenic differentiation, TNF-α or IGF1 response are enriched in specific pathways. Selected KEGG pathways within the top 10 enriched KEGG pathways of predicted miRNA targets in mouse for (A) targets of miRNAs which are differentially regulated during differentiation, (B) during differentiation with TNF-α exposure, or (C) IGF1 treatment.
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Fig1: Predicted targets of murine miRNAs associated with myogenic differentiation, TNF-α or IGF1 response are enriched in specific pathways. Selected KEGG pathways within the top 10 enriched KEGG pathways of predicted miRNA targets in mouse for (A) targets of miRNAs which are differentially regulated during differentiation, (B) during differentiation with TNF-α exposure, or (C) IGF1 treatment.

Mentions: Differentiation of murine cell line and human primary skeletal myoblasts was induced in vitro by serum withdrawal. After 24 hours we studied the impact of myogenic differentiation on miRNA expression. We identified a significant regulation of miRNAs which are among the 15% most abundantly expressed species in myoblasts or myotubes (Table 1, complete list in Additional file 1A,B). MiRNAs which are at least four-fold upregulated or downregulated during human or murine skeletal myoblast differentiation are listed in Table 1. We confirmed upregulation of miR-1, miR-133a, miR-133b and miR-206, which have previously been extensively implicated in skeletal muscle development and function [21]. A subset of seven differentially regulated miRNAs was simultaneously retrieved in the human and the murine skeletal muscle cells: miR-1, miR-133a-3p, miR-133b, miR-135a-3p, miR-206, miR-450b-5p, miR-451a, and miR-497-5p (Table 1A,B, Additional file 1A,B). Moreover, we identified several miRNAs which, to the best of our knowledge, have not been detected in skeletal myoblast differentiation before, such as mmu-miR-202-3p, mmu-miR-344-3p, mmu-miR-376b-5p, mmu-miR-409-3p, and hsa-miR-216a-5p (Additional file 1A,B). In addition, our data revealed regulation of miRNAs for which only an isoform or the corresponding 3p or 5p miRNA have previously been described in myoblast differentiation such as mmu-miR-322-3p (Additional file 1A,B). In vitro myoblast differentiation also involved miRNAs which are differentially expressed in primary muscular disorders (e.g. mmu-miR-146a-5p, mmu-miR-335-5p, hsa-miR-299-5p [11]), aged muscle (e.g. mmu-miR-434-5p [22], mmu-miR-451a [23]), or insulin resistant muscle in diabetes patients (e.g. has-miR-15a-5p [24], mmu-miR-503-5p [25]) (Additional file 1A, B). Target prediction and enrichment analysis for differentiation-related miRNAs revealed predicted targets enriched for functional annotations including the spliceosome, RNA degradation, peroxisome proliferator-activated receptor (PPAR) signalling pathway, and neuroactive ligand-receptor interaction (Additional file 2A, D). Moreover, predicted miRNA targets were overrepresented in KEGG pathways such as focal adhesion, MAPK signalling, axon guidance, neurotrophin signalling, and Wnt signalling (Figure 1A, Additional file 3A; Additional file 4A,B).Table 1


TNF-α and IGF1 modify the microRNA signature in skeletal muscle cell differentiation.

Meyer SU, Thirion C, Polesskaya A, Bauersachs S, Kaiser S, Krause S, Pfaffl MW - Cell Commun. Signal (2015)

Predicted targets of murine miRNAs associated with myogenic differentiation, TNF-α or IGF1 response are enriched in specific pathways. Selected KEGG pathways within the top 10 enriched KEGG pathways of predicted miRNA targets in mouse for (A) targets of miRNAs which are differentially regulated during differentiation, (B) during differentiation with TNF-α exposure, or (C) IGF1 treatment.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4325962&req=5

Fig1: Predicted targets of murine miRNAs associated with myogenic differentiation, TNF-α or IGF1 response are enriched in specific pathways. Selected KEGG pathways within the top 10 enriched KEGG pathways of predicted miRNA targets in mouse for (A) targets of miRNAs which are differentially regulated during differentiation, (B) during differentiation with TNF-α exposure, or (C) IGF1 treatment.
Mentions: Differentiation of murine cell line and human primary skeletal myoblasts was induced in vitro by serum withdrawal. After 24 hours we studied the impact of myogenic differentiation on miRNA expression. We identified a significant regulation of miRNAs which are among the 15% most abundantly expressed species in myoblasts or myotubes (Table 1, complete list in Additional file 1A,B). MiRNAs which are at least four-fold upregulated or downregulated during human or murine skeletal myoblast differentiation are listed in Table 1. We confirmed upregulation of miR-1, miR-133a, miR-133b and miR-206, which have previously been extensively implicated in skeletal muscle development and function [21]. A subset of seven differentially regulated miRNAs was simultaneously retrieved in the human and the murine skeletal muscle cells: miR-1, miR-133a-3p, miR-133b, miR-135a-3p, miR-206, miR-450b-5p, miR-451a, and miR-497-5p (Table 1A,B, Additional file 1A,B). Moreover, we identified several miRNAs which, to the best of our knowledge, have not been detected in skeletal myoblast differentiation before, such as mmu-miR-202-3p, mmu-miR-344-3p, mmu-miR-376b-5p, mmu-miR-409-3p, and hsa-miR-216a-5p (Additional file 1A,B). In addition, our data revealed regulation of miRNAs for which only an isoform or the corresponding 3p or 5p miRNA have previously been described in myoblast differentiation such as mmu-miR-322-3p (Additional file 1A,B). In vitro myoblast differentiation also involved miRNAs which are differentially expressed in primary muscular disorders (e.g. mmu-miR-146a-5p, mmu-miR-335-5p, hsa-miR-299-5p [11]), aged muscle (e.g. mmu-miR-434-5p [22], mmu-miR-451a [23]), or insulin resistant muscle in diabetes patients (e.g. has-miR-15a-5p [24], mmu-miR-503-5p [25]) (Additional file 1A, B). Target prediction and enrichment analysis for differentiation-related miRNAs revealed predicted targets enriched for functional annotations including the spliceosome, RNA degradation, peroxisome proliferator-activated receptor (PPAR) signalling pathway, and neuroactive ligand-receptor interaction (Additional file 2A, D). Moreover, predicted miRNA targets were overrepresented in KEGG pathways such as focal adhesion, MAPK signalling, axon guidance, neurotrophin signalling, and Wnt signalling (Figure 1A, Additional file 3A; Additional file 4A,B).Table 1

Bottom Line: Results reveal that i) TNF-α and IGF1 regulate miRNA expression during skeletal muscle cell differentiation in vitro, ii) microRNA targets can mediate the negative effect of TNF-α on fusion capacity of skeletal myoblasts by targeting genes associated with axon guidance, MAPK signalling, focal adhesion, and neurotrophin signalling pathway, iii) inhibition of miR-155 in combination with overexpression of miR-503 partially abrogates the inhibitory effect of TNF-α on myotube formation, and iv) MAPK/ERK inhibition might participate in modulating the effect of TNF-α and IGF1 on miRNA abundance.The inhibitory effects of TNF-α or the growth promoting effects of IGF1 on skeletal muscle differentiation include the deregulation of known muscle-regulatory miRNAs as well as miRNAs which have not yet been associated with skeletal muscle differentiation or response to TNF-α or IGF1.This study indicates that miRNAs are mediators of the inhibitory effect of TNF-α on myoblast differentiation.

View Article: PubMed Central - PubMed

Affiliation: Physiology Weihenstephan, ZIEL Research Center for Nutrition and Food Sciences, Technische Universität München, Weihenstephaner Berg 3, D-85354, Freising, Germany. meyers@wzw.tum.de.

ABSTRACT

Background: Elevated levels of the inflammatory cytokine TNF-α are common in chronic diseases or inherited or degenerative muscle disorders and can lead to muscle wasting. By contrast, IGF1 has a growth promoting effect on skeletal muscle. The molecular mechanisms mediating the effect of TNF-α and IGF1 on muscle cell differentiation are not completely understood. Muscle cell proliferation and differentiation are regulated by microRNAs (miRNAs) which play a dominant role in this process. This study aims at elucidating how TNF-α or IGF1 regulate microRNA expression to affect myoblast differentiation and myotube formation.

Results: In this study, we analyzed the impact of TNF-α or IGF1 treatment on miRNA expression in myogenic cells. Results reveal that i) TNF-α and IGF1 regulate miRNA expression during skeletal muscle cell differentiation in vitro, ii) microRNA targets can mediate the negative effect of TNF-α on fusion capacity of skeletal myoblasts by targeting genes associated with axon guidance, MAPK signalling, focal adhesion, and neurotrophin signalling pathway, iii) inhibition of miR-155 in combination with overexpression of miR-503 partially abrogates the inhibitory effect of TNF-α on myotube formation, and iv) MAPK/ERK inhibition might participate in modulating the effect of TNF-α and IGF1 on miRNA abundance.

Conclusions: The inhibitory effects of TNF-α or the growth promoting effects of IGF1 on skeletal muscle differentiation include the deregulation of known muscle-regulatory miRNAs as well as miRNAs which have not yet been associated with skeletal muscle differentiation or response to TNF-α or IGF1. This study indicates that miRNAs are mediators of the inhibitory effect of TNF-α on myoblast differentiation. We show that intervention at the miRNA level can ameliorate the negative effect of TNF-α by promoting myoblast differentiation. Moreover, we cautiously suggest that TNF-α or IGF1 modulate the miRNA biogenesis of some miRNAs via MAPK/ERK signalling. Finally, this study identifies indicative biomarkers of myoblast differentiation and cytokine influence and points to novel RNA targets.

Show MeSH
Related in: MedlinePlus