A role for RNA post-transcriptional regulation in satellite cell activation
A role for RNA post-transcriptional regulation in satellite cell activation
复制标题
DOI：
10.1186/2044-5040-2-21
复制
发表时间：
2012-01-01
期刊：
影响因子：
4.9
通讯作者：
Olwin, Bradley B.
中科院分区：
文献类型：
--
作者：
Farina, Nicholas H.;Hausburg, Melissa;Olwin, Bradley B.
背景：卫星细胞是负责肌肉维护和修复的常驻骨骼肌干细胞。在静息肌肉中，卫星细胞保持静止状态。卫星细胞激活诱导肌源性承诺因子 MyoD 和进入细胞周期，以促进向增殖性成肌细胞群体的转变，最终退出周期并再生肌肉组织。对静止卫星细胞转变为转运放大成肌细胞的分子机制知之甚少。方法：使用 Affymetrix 430v2 基因芯片探测未受伤骨骼肌以及肌肉损伤后 12 小时的野生型和 Syndecan-4 缺失小鼠中通过 FACS 分离的卫星细胞，并通过 Spotfire(tm) 和 Ingenuity 进行分析 路径分析分别识别与卫星细胞激活相关的基因表达变化和网络。对靶基因的额外分析确定了在卫星细胞激活过程中表现出动态表达变化的 miRNA。使用 miRIDIAN 发夹抑制剂评估 miRNA 的功能。结果：无偏基因表达筛选发现，肌肉损伤后 12 小时内，体内卫星细胞中有 4,000 多个基因差异表达，其中 50% 以上急剧下降。 RNA结合蛋白和参与转录后调节的基因显着过度表达，而剪接因子优先下调，mRNA稳定性基因优先上调。此外，六种通过计算识别的 miRNA 通过肌肉再生和卫星细胞表现出新的表达。六个 miRNA 中的三个被发现可以调节卫星细胞的命运。结论：静止的卫星细胞主动维持在准备响应外部信号而激活的状态。卫星细胞的激活似乎受到转录后基因调控的调节。
Background: Satellite cells are resident skeletal muscle stem cells responsible for muscle maintenance and repair. In resting muscle, satellite cells are maintained in a quiescent state. Satellite cell activation induces the myogenic commitment factor, MyoD, and cell cycle entry to facilitate transition to a population of proliferating myoblasts that eventually exit the cycle and regenerate muscle tissue. The molecular mechanism involved in the transition of a quiescent satellite cell to a transit-amplifying myoblast is poorly understood.Methods: Satellite cells isolated by FACS from uninjured skeletal muscle and 12 h post-muscle injury from wild type and Syndecan-4 null mice were probed using Affymetrix 430v2 gene chips and analyzed by Spotfire(tm) and Ingenuity Pathway analysis to identify gene expression changes and networks associated with satellite cell activation, respectively. Additional analyses of target genes identify miRNAs exhibiting dynamic changes in expression during satellite cell activation. The function of the miRNAs was assessed using miRIDIAN hairpin inhibitors.Results: An unbiased gene expression screen identified over 4,000 genes differentially expressed in satellite cells in vivo within 12 h following muscle damage and more than 50% of these decrease dramatically. RNA binding proteins and genes involved in post-transcriptional regulation were significantly over-represented whereas splicing factors were preferentially downregulated and mRNA stability genes preferentially upregulated. Furthermore, six computationally identified miRNAs demonstrated novel expression through muscle regeneration and in satellite cells. Three of the six miRNAs were found to regulate satellite cell fate.Conclusions: The quiescent satellite cell is actively maintained in a state poised to activate in response to external signals. Satellite cell activation appears to be regulated by post-transcriptional gene regulation.