Live Imaging of Skin Regeneration

总结 组织稳态和再生由干细胞维持，干细胞必须不断更新 同时跟上新的分化细胞类型的需求，以取代那些在整个过程中丢失的细胞类型。 组织的生命如果不能适当地平衡这两个过程，可能会导致一系列问题，包括 受损的器官功能和组织修复，以及组织过度生长和癌症。了解基本 干细胞自我更新和分化的这种微妙平衡的基础机制是一个必不可少的 预防和治疗多种疾病的步骤。 我们仍然缺乏基本的知识，这些干细胞的行为是如何调节组织过程中， 在完整的活组织中再生这项提案的目的是了解个体干细胞 决定是在干细胞群体中做出的，这样它们的行为就能在群体中保持平衡。 更广泛的组织背景，同时保留结构和功能。在解决 这些基本问题在于无法在一个完整的环境中研究这些动态细胞过程。 哺乳动物。为此，我的实验室建立了一种直接可视化和操纵的体内策略， 干细胞在活小鼠的皮肤上皮，利用其独特的可及性，连续 再生在其一生中，和存在多个干细胞群体，使用不同的 再生策略 使用一种新的，非侵入性的双光子成像方法，我们终于能够跟踪干细胞， 它们会随着时间的推移自我更新和分化。为了了解干细胞的行为是如何平衡的， 确定干细胞的形状，位置和分子特征如何影响细胞命运的决定和整体 组织的再生能力，我们已经将我们的成像方法与新开发的方法相结合， 让我们能够操纵活老鼠体内的每一个细胞及其行为。这种独特的组合， 新的体内成像工具的专业知识和发展使我们能够首先定义 组织再生，以前无法达到，揭示了干细胞的意想不到的原则， 第二，了解干细胞行为之间的复杂相互作用， 时间 这项提案的目的是促进我们对干细胞行为如何平衡的理解， 通过使用尖端成像的综合方法， 技术、基因操作和细胞生物学。鉴于干细胞生物学的许多方面已经被 在其他器官中广泛保守，我们的发现也将与其他组织相关， 为一系列疾病的治疗提供了重要基础。

Summary Tissue homeostasis and regeneration are sustained by stem cells, which must both continually renew themselves while keeping up with the demand of new differentiated cell types to replace those lost throughout the life of a tissue. Failure to properly balance these two processes can lead to a host of problems, including impaired organ function and tissue repair, as well as tissue overgrowth and cancer. Understanding the basic mechanisms underlying this delicate equilibrium of stem cell self-renewal and differentiation is an essential step in preventing and treating a wide range of diseases. We still lack fundamental knowledge of how these stem cell behaviors are regulated during tissue regeneration in an intact, living tissue. The goal of this proposal is to understand how individual stem cell decisions are made within the stem cell population so that collectively their behaviors remain balanced within the broader context of the tissue, while preserving both structure and function. The challenge in addressing these fundamental questions lies in the inability to study these dynamic cellular processes in an intact mammal. To this end, my laboratory has established an in vivo strategy to directly visualize and manipulate stem cells in the skin epithelium of live mice, taking advantage of its unique accessibility, continuous regeneration throughout its lifetime, and the presence of multiple stem cell populations that use distinct regenerative strategies. Using a novel, non-invasive two-photon imaging approach, we are finally able to follow stem cells as they self-renew and differentiate over time. In order to understand how stem cell behaviors are balanced , and determine how a stem cell's shape, position and molecular character affect cell fate decisions and the overall regenerative ability of the tissue, we have combined our imaging approach with newly developed methods that allow us to manipulate each cell and their behavior individually in a live mouse. This unique combination of expertise, knowledge, and development of novel in vivo imaging tools has allowed us to first, define aspects of tissue regeneration that were previously inaccessible, revealing unexpected principles of stem cells and second, to understand the complex interplay between stem cell behaviors that fuel tissue regeneration over time. The goal of this proposal is to advance our understanding of how stem cell behaviors are balanced to sustain tissue regeneration over time through the use of an integrated approach of cutting edge imaging technology, genetic manipulation and cell biology. Given that many aspects of stem cell biology have been shown to be widely conserved in other organs, our findings will be relevant to other tissues as well, and will provide an important foundation for the treatment of a range of diseases.