Transcriptional regulation of retinal mitochondrial function and cell cycle

描述（由申请人提供）：视网膜发生需要视网膜祖细胞（RPC）增殖和分化的严格控制平衡。对这一机制的疏解通常会导致严重的神经发育障碍或癌症。我们的长期目标是阐明RPC细胞周期调节与神经元分化之间的转录机制。在本研究中，实验将确定转录调控蛋白浪蛋白（Thap11）在视网膜形成中的作用。Ronin是最近发现的一种新的胚胎干细胞（ESC）多能性因子，影响ESC的增殖和生长。Ronin也在发育中的大脑和视网膜中表达，但其在这些组织中的作用尚不清楚。在初步研究中，我们发现Ronin突变体的视网膜表型改变了Cyclin D1缺失的小鼠，从而暗示了Ronin是细胞周期G1到s期转变的调节剂。然而，初步的Ronin视网膜ChIP-seq数据分析显示，线粒体基因富集，而不是细胞周期机制。最近，线粒体通过促进Cyclin E活性和进入s期而成为果蝇和啮齿动物G1期向s期转变的关键调节因子。因此，我们假设Ronin通过直接调节线粒体正常功能和促进s期进入所需的基因来影响RPC细胞周期。为了验证这一假设，我们组建了一个具有不同专业知识的团队，利用基因功能丧失和获得实验、代谢谱、活体视网膜显微镜和基因组学来促进协同的多学科方法。在完成这一提议后，我们期望我们将确定一种新的转录机制，将线粒体功能与rpc中的细胞周期进程偶联。对多能、增殖性RPCs转录调控的深入了解，最终将为视网膜细胞替代疗法以及线粒体生物能量学和细胞周期界面功能的新型癌症药物靶点提供有效的策略。

DESCRIPTION (provided by applicant): Retinogenesis requires a tightly controlled balance of retinal progenitor cell (RPC) proliferation and differentiation. Deregulation of this mechanism often results in profound neuro-developmental disorders or cancer. Our long term goal is to elucidate the transcriptional mechanisms coupling RPC cell cycle regulation to neuronal differentiation. In this proposal, experiments will define the role of the transcriptional regulato Ronin (Thap11) in retinogenesis. Ronin was identified recently as a novel embryonic stem cell (ESC) pluripotency factor, influencing ESC proliferation and growth. Ronin is also expressed throughout the developing brain and retina, but its role in these tissues is unknown. In preliminary studies, we have found that Ronin mutant retinae phenocopy the Cyclin D1 null mice thereby implicating Ronin as a regulator of the cell cycle G1 to S-phase transition. However, analysis of preliminary Ronin retinal ChIP-seq data showed enrichment for mitochondrial genes rather than cell cycle machinery. Recently, mitochondria have emerged as critical regulators of the G1 to S-phase transition in both flies and rodents by promoting Cyclin E activity and entry into S-phase. Therefore, we hypothesize that Ronin influences the RPC cell cycle by directly regulating genes required for proper mitochondrial function and promotion of S-phase entry. To test this hypothesis, we have assembled a team with diverse expertise, to facilitate a synergistic, multi- disciplinary approach using genetic loss- and gain-of-function experiments, metabolic profiling, live retinal microscopy and genomics. Upon completion of this proposal, we expect that we will have identified a new transcriptional mechanism that couples mitochondrial function to cell cycle progression in RPCs. This deeper understanding of the transcriptional regulation of multipotent, proliferative RPCs will ultimately inform efficacious strategies for retinal cell replacement therapies as well as novel cancer drug targets functioning at the interface of mitochondrial bioenergetics and the cell cycle.