Transcriptional regulation of retinal mitochondrial function and cell cycle

描述（由申请人提供）：视网膜发生需要严格控制视网膜祖细胞（RPC）增殖和分化的平衡。这种机制的失调往往导致严重的神经发育障碍或癌症。我们的长期目标是阐明耦合RPC细胞周期调控神经元分化的转录机制。在这个提议中，实验将确定转录调节因子Ronin（Thap 11）在视网膜发生中的作用。Ronin是近年来发现的一种新的胚胎干细胞（ESC）多能性因子，可影响ESC的增殖和生长。Ronin也在整个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突变体视网膜表型复制细胞周期蛋白D1无效的小鼠，从而牵连Ronin作为调节细胞周期G1期到S期的转变。然而，初步Ronin视网膜ChIP-seq数据的分析显示线粒体基因而不是细胞周期机制的富集。最近，线粒体已成为果蝇和啮齿类动物中G1到S-期转变的关键调节因子，通过促进细胞周期蛋白E活性和进入S-期。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，以促进使用遗传功能丧失和获得实验、代谢分析、活体视网膜显微镜和基因组学的协同、多学科方法。在完成这项提案后，我们预计，我们将确定一个新的转录机制，耦合线粒体功能的细胞周期进程中的RPC。这种对多能性、增殖性RPC的转录调控的更深入理解将最终为视网膜细胞替代疗法以及在线粒体生物能量学和细胞周期界面发挥作用的新型癌症药物靶点提供有效策略。

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.