Tokugawa Seiji, Sakuma Kunihiro, Fujiwara Hiroyoshi, Hirata Miyuki, Oda Ryo, Morisaki Shinsuke, Yasuhara Masahiro, Kubo Toshikazu
Department of Orthopaedics, Graduate School of Medical Science, Kyoto Prefectural University of Medcicine, Kamigyo-ku, Kyoto.
Neuropathology. 2009 Jun;29(3):211-8. doi: 10.1111/j.1440-1789.2008.00967.x. Epub 2008 Oct 20.
Protein kinase C (PKC) is a key enzyme in regulating a variety of cellular functions. PKCtheta is the most abundant PKC isoform expressed in skeletal muscle. However, the functional role of PKCtheta linked to muscle regeneration has not yet been identified. Using reverse transcription (RT)-PCR and immunofluorescence analysis, we investigated the expression patterns of PKCtheta in normal and regenerating tibialis anterior (TA) muscles in the rat. The amount of PKCtheta mRNA in the muscle increased from the 4th to 6th post-surgical day. Immunofluorescence revealed PKCtheta protein in quiescent satellite cells identified by c-Met. PKCtheta immunoreactivity was not observed in many proliferating satellite cells by labeling with BrdU in the regenerating muscle. At 4, 6 and 10 days postsurgery, PKCtheta immunoreactivity was observed in half the differentiating satellite cells labeling with myogenin. After 4 and 6 days, the localization of PKCtheta coincided with those of Pax7 and TGF-beta. Thus, PKCtheta may play an important role in inhibiting differentiation and maintaining the quiescent satellite cells in muscle regeneration.
蛋白激酶C（PKC）是调节多种细胞功能的关键酶。PKCθ是骨骼肌中表达最丰富的PKC亚型。然而，与肌肉再生相关的PKCθ的功能作用尚未明确。我们利用逆转录（RT）-PCR和免疫荧光分析，研究了PKCθ在正常和再生的大鼠胫前肌（TA）中的表达模式。术后第4天至第6天，肌肉中PKCθ mRNA的量增加。免疫荧光显示，通过c-Met鉴定的静止卫星细胞中有PKCθ蛋白。在再生肌肉中，用BrdU标记后，在许多增殖卫星细胞中未观察到PKCθ免疫反应性。术后4天、6天和10天，在用生肌调节因子标记的半数分化卫星细胞中观察到PKCθ免疫反应性。术后4天和6天后，PKCθ的定位与配对盒蛋白7（Pax7）和转化生长因子-β（TGF-β）的定位一致。因此，PKCθ可能在抑制分化和维持肌肉再生中的静止卫星细胞方面发挥重要作用。
