NF‐κB activation by disruption of microtubule array during myogenesis of L6 cells

Abstract

We have previously reported that NF‐κB is involved in the regulation of nitric oxide synthase gene expression during differentiation of chick embryonic myoblasts. However, how NF‐κB is timely activated during myogenesis remains elusive. One of the most prominent events in myogenesis is myoblast membrane fusion, which is accompanied with massive cytoskeletal reorganization. Here we show that the activity of NF‐κB markedly increases in L6 rat myogenic cells that have just initiated morphological changes by treating nocodazole, a microtubule‐disrupting agent. Furthermore, the induction of NF‐κB activation was closely correlated with the myoblast fusion. In addition, a variety of agents that disrupt microtubules stimulated the myoblast fusion as well as the induction of NF‐κB activation. In contrast, taxol, a microtubule‐stabilizing agent, suppressed the induction of NF‐κB activation and inhibited spontaneous differentiation of L6 cells as well. In addition, we found that the NF‐κB in the cells consists of p50/p65 heterodimers. These results support the idea that reorganization of microtubule at early stages of differentiation plays a role as a signal for NF‐κB activation during myogenesis.

Key words:

• NF‐κB activation
• Microtubule
• Myogenesis

Notes

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