Constitutive Expression of Insulin Receptor Substrate (IRS)-1 Inhibits Myogenic Differentiation through Nuclear Exclusion of Foxo1 in L6 Myoblasts
2011

How IRS-1 Affects Muscle Cell Development

publication 10 minutes Evidence: moderate

Author Information

Author(s): Hakuno Fumihiko, Yamauchi Yoko, Kaneko Gen, Yoneyama Yosuke, Nakae Jun, Chida Kazuhiro, Kadowaki Tatsuhiko, Yamanouchi Keitaro, Nishihara Masugi, Takahashi Shin-Ichiro

Primary Institution: The University of Tokyo

Hypothesis

Does the expression of IRS-1 inhibit myogenic differentiation in L6 myoblasts?

Conclusion

Constitutive expression of IRS-1 inhibits myogenic differentiation by preventing Foxo1 from entering the nucleus.

Supporting Evidence

  • IRS-1 expression was found to inhibit the differentiation of L6 myoblasts into myotubes.
  • Foxo1 localization was altered in cells expressing IRS-1, preventing its nuclear entry.
  • Prolonged activation of IGF-I signaling was observed in IRS-1 expressing cells.

Takeaway

When a protein called IRS-1 is always present in muscle cells, it stops them from growing into muscle fibers by keeping another protein, Foxo1, out of the cell's control center.

Methodology

L6 myoblasts were stably transfected with IRS-1 and analyzed for differentiation and signaling pathways.

Potential Biases

Potential bias in the interpretation of results due to reliance on a specific experimental model.

Limitations

The study primarily focuses on a single cell line, which may not fully represent in vivo conditions.

Statistical Information

P-Value

p<0.05

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1371/journal.pone.0025655

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