MyoD表达的阶段限制性抑制对牛成肌细胞终末分化的影响:Myf5或肌细胞生成素表达无改变。
Effect of phase limited inhibition of MyoD expression on the terminal differentiation of bovine myoblasts: no alteration of Myf5 or myogenin expression.
作者信息
Muroya Susumu, Nakajima Ikuyo, Oe Mika, Chikuni Koichi
机构信息
Department of Animal Products, National Institute of Livestock and Grassland Science, Tsukuba, Ibaraki 305-0901, Japan.
出版信息
Dev Growth Differ. 2005 Sep;47(7):483-92. doi: 10.1111/j.1440-169X.2005.00822.x.
To investigate the roles played by MyoD in the terminal differentiation of satellite cell-derived myoblasts, the effect of antisense inhibition of MyoD expression was examined in bovine adult myoblast culture, in which inhibition treatment was limited to the terminal differentiation phase. MyoD antisense oligonucleotide DNA (AS-mD) suppressed the formation of multinucleated myotubes in the cell culture. Myotube formation was suppressed even when AS-mD treatment was limited to the period preceding the onset of myotube formation. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis revealed that treatment with AS-mD suppressed the expression of myosin heavy chain embryonic isoform and troponin T isoforms at 4 days after the induction of differentiation. AS-mD also suppressed the expression of MRF4, but did not alter the expression of either Myf5 or myogenin, in contrast to previous results using mouse cells possessing MyoD(-/-) genetic background. These findings suggest that MyoD controls myogenesis but not Myf5 or myogenin mRNA expression during the terminal differentiation phase. Furthermore, among the alpha4, alpha5, alpha6, and alpha7 integrins, alpha4, alpha5, and alpha7 integrin expression was suppressed by AS-mD treatment, in parallel with the suppression of myotube formation, which suggests that MyoD controls myotube formation by regulating the expression of alpha4, alpha5, and alpha7 integrins.
为了研究MyoD在卫星细胞来源的成肌细胞终末分化中所起的作用,我们在牛成年成肌细胞培养中检测了MyoD表达的反义抑制作用,其中抑制处理仅限于终末分化阶段。MyoD反义寡核苷酸DNA(AS-mD)抑制了细胞培养中多核肌管的形成。即使AS-mD处理仅限于肌管形成开始前的时期,肌管形成也受到抑制。逆转录聚合酶链反应(RT-PCR)分析显示,在诱导分化4天后,AS-mD处理抑制了肌球蛋白重链胚胎异构体和肌钙蛋白T异构体的表达。与之前使用具有MyoD(-/-)基因背景的小鼠细胞的结果相反,AS-mD还抑制了MRF4的表达,但没有改变Myf5或生肌调节因子的表达。这些发现表明,在终末分化阶段,MyoD控制肌生成,但不控制Myf5或生肌调节因子mRNA的表达。此外,在α4、α5、α6和α7整合素中,α4、α5和α7整合素的表达受到AS-mD处理的抑制,这与肌管形成的抑制同时发生,这表明MyoD通过调节α4、α5和α7整合素的表达来控制肌管形成。