Live Imaging of Skin Regeneration

摘要 组织的动态平衡和再生是由干细胞维持的，干细胞必须不断更新 同时跟上新分化细胞类型的需求，以取代整个过程中丢失的细胞类型 纸巾的寿命。如果不能正确平衡这两个过程，可能会导致一系列问题，包括 器官功能和组织修复受损，以及组织过度生长和癌症。了解基本知识 干细胞自我更新和分化的微妙平衡背后的机制是至关重要的 在预防和治疗各种疾病方面迈出了一步。 我们仍然缺乏关于这些干细胞行为是如何在组织中被调节的基础知识。 在一个完整的、活的组织中再生。这项提议的目标是了解单个干细胞是如何 决定是在干细胞群体中做出的，这样他们的行为总体上保持平衡 更广泛的组织背景，同时保留结构和功能。解决以下问题的挑战 这些根本的问题在于无法完整地研究这些动态的细胞过程 哺乳动物。为此，我的实验室建立了一种活体策略，以直接可视化和操纵 干细胞在活体小鼠的皮肤上皮中，利用其独特的可及性，连续 在其整个生命周期中再生，以及使用不同的 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总体 为了增强组织的再生能力，我们将我们的成像方法与新开发的方法相结合 允许我们在活着的鼠标中单独操作每个细胞及其行为。这一独特的组合 新的活体成像工具的专业知识和开发使我们能够首先定义 以前无法获得的组织再生，揭示了干细胞和 其次，要了解干细胞行为之间复杂的相互作用，这些行为会促进组织再生 时间到了。 这项提议的目标是促进我们对干细胞行为如何平衡的理解 通过使用集成的尖端成像方法，随时间保持组织再生 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 我们的发现显示在其他器官中广泛保守，我们的发现也将与其他组织相关，并将 为治疗一系列疾病提供了重要的基础。

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.