Systematic investigation of microRNA function in developing neurons

正常的脑功能严重依赖于调节基因表达的生物网络的完整性。最近在蠕虫的研究中发现，microRNAs构成了细胞转录后水平上基因表达调控的一类新的关键调控因子。在缺乏所有microrna的动物模型中进行的研究表明，它们对生命和正常的大脑发育至关重要。目前，诸如microrna如何相互作用以及它们如何在神经生物学中起全局作用等基本问题仍未得到解答。此外，与神经元发育有关的microrna（及其调节的基因）的数量和身份，特别是在哺乳动物系统中，是未知的。在目前的项目中，我们想利用非常明确的初级海马神经元系统来解决这些问题。由于在培养过程中，几乎所有的细胞都以同步的方式遵循大脑中不同的分化步骤，从神经元圆形前体细胞到具有清晰的轴突和树突亚域和突触活性的完全极化的神经元，因此有可能在定量和定性上遵循基因表达的逐渐变化。我们建议研究microrna的作用，首先在全球水平，然后单独，在调节神经元表型。这些实验将允许首次系统地研究microrna如何促进神经网络的复杂性。

Normal brain function critically depends on the integrity of biological networks that regulate the expression of genes. Discovered recently from studies in worms, microRNAs constitute a novel class of key regulators of gene expression regulation at the posttranscriptional level in the cell. Studies in animal models lacking all microRNAs have shown that they are essential for life as well as proper brain development. At this moment, fundamental questions such as how microRNAs interact and how they are globally implicated in neurobiology remain unanswered. Furthermore, the number and identity of microRNAs (and genes they regulate) implicated in neuronal development, particularly in a mammalian system, are unknown. In the current project we want to make use of the very well defined primary hippocampal neuron system to address these questions. As almost all the cells in culture follow in a synchronized way the different differentiation steps as seen in brain, from a neuronal round precursor cell towards fully polarized neurons with clear axon and dendritic subdomains and synaptic activity, it is possible to follow in a quantitative and qualitative way gradual changes in gene expression. We propose to investigate the role of microRNAs, first at a global level and then individually, in modulating the neuronal phenotype. These experiments will allow a first systematic investigation of how microRNAs contribute to the complexity of the neuronal network.