In order to investigate the mechanisms regulating skeletal muscle homeostasis and the balance between atrophic and hypertrophic signals, and based on the fact that often factors with a positive (or negative) role in in vitro myogenesis have the same role in muscle homeostasis in vivo, we have exposed muscle cell cultures to Tumor Necrosis Factor-α (TNF-α), Insulin-like Growth Factor I (IGF-I) or their combination in two different experimental sets: L6 myogenic cells were induced to differentiate either in the absence or presence of these factors; alternatively, the same cells were differentiated with standard methods (by lowering the serum concentration) and then exposed to the above factors. With this approach we could confirm that TNF-α and IGF-I have opposite effects on skeletal muscle differentiation. However, we showed that both TNF-α and IGF-I induce muscle hypertrophy to the same extent when delivered to a promiscuous culture of myotubes and single cells. This striking observation may contribute to explain why muscle hypertrophy often involves muscle damage (and a consequent cytokine-mediated cycle of inflamma-tion). On the other hand, we extended previous observations on IGF-I hypertrophic effects on skeletal muscle cell obtained by using transgenic cell lines: here we show that IGF-I retains its ability to positively affect myogenesis even on cell cultures which have already reached a significant fusion index. Taken together our observations indicate that TNF-α has differential effects on myogenic differentiation and trophysm depending on the time it has been added to the cell culture. Both TNF-α and IGF-I can promote significantly myotube growth when added to muscle cell culture previously induced to differentiate.

Bimodal effects of TNF-alpha on differentiation and hypertrophy of skeletal muscle cell cultures / Moresi, Viviana; Adamo, Sergio; Coletti, Dario. - In: BASIC AND APPLIED MYOLOGY. - ISSN 1120-9992. - STAMPA. - 16:5, 6(2006), pp. 163-168.

Bimodal effects of TNF-alpha on differentiation and hypertrophy of skeletal muscle cell cultures

MORESI, Viviana;ADAMO, Sergio;COLETTI, Dario
2006

Abstract

In order to investigate the mechanisms regulating skeletal muscle homeostasis and the balance between atrophic and hypertrophic signals, and based on the fact that often factors with a positive (or negative) role in in vitro myogenesis have the same role in muscle homeostasis in vivo, we have exposed muscle cell cultures to Tumor Necrosis Factor-α (TNF-α), Insulin-like Growth Factor I (IGF-I) or their combination in two different experimental sets: L6 myogenic cells were induced to differentiate either in the absence or presence of these factors; alternatively, the same cells were differentiated with standard methods (by lowering the serum concentration) and then exposed to the above factors. With this approach we could confirm that TNF-α and IGF-I have opposite effects on skeletal muscle differentiation. However, we showed that both TNF-α and IGF-I induce muscle hypertrophy to the same extent when delivered to a promiscuous culture of myotubes and single cells. This striking observation may contribute to explain why muscle hypertrophy often involves muscle damage (and a consequent cytokine-mediated cycle of inflamma-tion). On the other hand, we extended previous observations on IGF-I hypertrophic effects on skeletal muscle cell obtained by using transgenic cell lines: here we show that IGF-I retains its ability to positively affect myogenesis even on cell cultures which have already reached a significant fusion index. Taken together our observations indicate that TNF-α has differential effects on myogenic differentiation and trophysm depending on the time it has been added to the cell culture. Both TNF-α and IGF-I can promote significantly myotube growth when added to muscle cell culture previously induced to differentiate.
2006
-
01 Pubblicazione su rivista::01a Articolo in rivista
Bimodal effects of TNF-alpha on differentiation and hypertrophy of skeletal muscle cell cultures / Moresi, Viviana; Adamo, Sergio; Coletti, Dario. - In: BASIC AND APPLIED MYOLOGY. - ISSN 1120-9992. - STAMPA. - 16:5, 6(2006), pp. 163-168.
File allegati a questo prodotto
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/365368
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact