| Budget Amount *help |
¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000)
Fiscal Year 2012: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2011: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
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| Research Abstract |
Plasma in electrical discharge is a partially ionized gas, containing radicals, electrons, positive and negative ions, and various excited atoms. Recently, many types of low-temperature atmospheric plasma devices have been developed for medical applications. In the present study, we investigate the effect of low-temperature atmospheric plasma exposure on proliferation and differentiation of C2C12 myoblast. The low-temperature atmospheric pressure gas-plasma was generated through an electrical discharge in an argon gas. One min of plasma exposure every 24 h inhibited the cell proliferation without cell death. Cell numbers in plasma exposure groups were 42.2% and 32.9% when compared to the control groups at 24 h and 48 h after the plasma exposure, respectively. On the other hand, the marker proteins for the myoblast differentiation, such as myogenin and myosin heavy chain expressions were not affected by plasma exposure. Plasma exposure increased the phosphorylation of extracellular-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) at 30 min after the exposure. However, phosphorylation of ERK and JNK was markedly decreased less than control levels at 1 and 4 h after the plasma exposure, respectively, and returned to the control levels at 24 h. By flow cytometric analysis, it revealed that plasma exposure increased the % of the cell in the G2/M phase at 8 h after the exposure. It was found that down-regulation of cdc2/cyclin B1, which regulates G2/M checkpoint in plasma-exposed cells. The expression of p21 Waf-1/Cip-1, which was known to control the entry of cells at the G2/M phase transition checkpoint was also elevated in plasma-exposed cells. In conclusion, low-temperature atmospheric plasma exposure retarded proliferation of C2C12 myoblast by G2/M arrest. Down-regulation of ERK and JNK activity and modulation of cell cycle checkpoint proteins may be involved in plasma exposure-induced cell cycle arrest.
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