Decoding the metabolic requirements for vertebrate appendage regeneration

摘要 与人类不同的是，一些动物能够在严重受伤后无疤痕地愈合和再生丢失的附肢。 附件再生需要快速和仔细调节的细胞增殖来取代丢失的组织，以及 天生的合成代谢过程。尽管生物合成作为再生愈合的一部分是基本需要的，我们 缺乏对损伤如何与使细胞增殖的新陈代谢变化相联系的机械理解 和增长。重新创造能够促进生长的新陈代谢条件对于培养 在通常有限的生物体中再生的成功，比如我们自己。在这项提案中，我们 利用两个优势阐明脊椎动物附肢再生的代谢需求。这个 首先是来自其他依赖有氧糖酵解的高增殖细胞类型的一套机制见解。 将葡萄糖转化为葡萄糖-6-磷酸，一种多用途的核苷酸和磷脂生物合成前体 制作。我们的初步数据表明，这是附肢再生的共同策略。第二 是非洲爪蛙蝌蚪附肢再生的独特上下文专一性，这一点在 营养来源、发育阶段和附属物类型的基础。这种上下文的特殊性为我们提供了 有机会直接将再生结构与其非再生结构以及其他非再生结构进行比较 再生结构，从而定义增强或限制新陈代谢格局的特定特征 再生的结果。在这个提议中，我们将检验中心假设，即再生成功是由决定的 通过组织快速重塑新陈代谢格局和将营养物质输送到生物合成的能力。 我们将通过首先定义在再生条件下占主导地位的代谢范式来检验这一假设： 糖酵解、磷酸戊糖途径或氧化磷酸化。然后，我们将确定共享和上下文- 代谢重新编程的特定特征，对比再生结构和 非洲爪哇蝌蚪不同发育阶段的非再生结构。我们以以下方式结束 构建再生新陈代谢的调控图景，从功能上测试候选调控 转录因子，并定义代谢基因的表达如何在细胞之间分割或整合 类型。

SUMMARY In contrast to humans, some animals are able to scarlessly heal and regrow lost appendages after major injury. Appendage regeneration requires rapid and carefully regulated cell proliferation to replace lost tissue, an inherently anabolic process. Despite the fundamental need for biosynthesis as part of regenerative healing, we lack a mechanistic understanding of how injury is coupled to metabolic changes that enable cell proliferation and growth. Re-creating the metabolic conditions that enable growth is critical to being able to foster regenerative success in organisms where it is normally limited, such as ourselves. In this proposal, we leverage two advantages to articulate the metabolic requirements for vertebrate appendage regeneration. The first is a suite of mechanistic insights from other highly proliferative cell types, which rely on aerobic glycolysis to convert glucose to glucose-6-phosphate, a versatile biosynthetic precursor for nucleotide and phospholipid production. Our preliminary data suggest that this is a shared strategy in appendage regeneration. The second is the unique context-specificity of appendage regeneration in Xenopus tadpoles, which is lost or gained on the basis of nutrient source, developmental stage, and appendage type. This context specificity gives us the opportunity to directly compare regenerative structures to their non-regenerative counterparts and to other non- regenerative structures, thereby defining the specific features of the metabolic landscape that enhance or limit regenerative outcome. In this proposal we will test the central hypothesis that regenerative success is dictated by the ability of tissues to rapidly remodel their metabolic landscape and funnel nutrients toward biosynthesis. We will test this hypothesis by first defining the metabolic paradigm that dominates in regenerative conditions: glycolysis, pentose phosphate pathway, or oxidative phosphorylation. We will then identify shared and context- specific features of metabolic reprogramming, contrasting the metabolic profile of regenerative structures and non-regenerative structures at different developmental stages of the Xenopus tadpole. We conclude by building a regulatory landscape of metabolism in regeneration, functionally testing candidate regulatory transcription factors, and defining how metabolic gene expression is partitioned or integrated between cell types.