Gene expression regulatory circuitry and microRNAs in midbrain dopamine neurons

许多发育和成人大脑疾病与中脑 多巴胺神经元（mDN），包括帕金森病（PD），精神分裂症，自闭症， 运动障碍和毒瘾因此，管理这些问题的基本机制 这些细胞的发育和功能非常重要。在之前的研究中，我们和 其他人则研究了基本的监管程序，例如 多巴胺生物合成途径中关键酶的表达 多巴胺神经元的发育、功能和存活。然而，从这些可以清楚地看出， 研究表明，所有这些过程都非常复杂。为 例如，至少两种转录因子Nurr 1和Pitx 3协同作用， 在简化的基于ES细胞的细胞中控制晚期发育mDN标志物的表达 文化模式最近，在初步数据和已发表的手稿中，我的实验室 已经发现了转录后的复杂性增加的证据 在mDN的发展和功能的背景下，通过microRNAs（miRNAs）的调节。 miRNA是进化上保守的18-25个核苷酸的非蛋白质编码转录物 在基因表达的转录后调节中起重要作用 在发展过程中。具体来说，我们发现了一种microRNA，miR-133 b， 在mDN中，在具有Pitx 3的调节反馈回路中起作用。在这里我们建议 为了更广泛地定义miRNA调控基因表达的复杂程度， 在mDNs，并确定这些形式的调节在体内的功能。最后， 这种形式的调节可能在mDN相关疾病中发挥作用， 此外，这些机制的操作提供了潜在的治疗途径。 我们想验证两个假设： 1. miRNAs在调节mDN中起作用，无论是在与mDN的反馈回路中， 转录因子和直接调节关键的mDN目标。 2.这种调控网络在体内的mDNs中起着重要的功能作用。

A number of developmental and adult brain disorders are associated with midbrain dopamine neurons (mDNs), including Parkinson's disease (PD), schizophrenia, autism, dyskinesias, and drug addiction. Thus, the fundamental mechanisms that regulate the development and function of these cells are of great import. In prior studies, we and others have investigated basic regulatory processes, such as regulation of the expression of key enzymes in the dopamine biosynthetic pathway in the context of dopamine neuron development, function, and survival. However, it is clear from these studies that there is a high level of complexity governing all of these processes. For instance, at least 2 transcription factors, Nurr1 and Pitx3, function synergistically to govern expression of late developmental mDN markers in simplified ES cell-based culture models. More recently, in preliminary data and a published manuscript, my lab has found evidence of an added layer of complexity involving post-transcriptional regulation by microRNAs (miRNAs) in the context of mDN development and function. miRNAs are evolutionarily conserved, 18-25 nucleotide non-protein coding transcripts that play an important function in post-transcriptional regulation of gene expression during development. Specifically, we identified a microRNA, miR-133b, that is enriched in mDNs and functions within a regulatory feedback circuit with Pitx3. Here we propose to more broadly define the level of complexity of gene expression regulation by miRNA in mDNs, and to determine the function of these forms of regulation in vivo. Ultimately, such forms of regulation are likely to play a role in mDN-associated diseases, and furthermore manipulations of these mechanisms offer potential avenues for therapies. We wish to test two hypotheses: 1. miRNAs function in the regulation of mDNs, both within feedback circuits with mDN transcription factors and by the direct regulation of key mDN targets. 2. Such regulatory networks play functionally important roles in mDNs in vivo.