Unraveling the interplay between metabolism, epigenetics and stem cell fate in the hair follicle

项目摘要 新出现的证据揭示了干细胞（SC）在细胞代谢中的关键作用， 更新和分化以维持组织稳态。然而，很少有人知道如何机械地 SC在其体内生态位内的细胞命运决定期间整合代谢刺激。此外，若干 代谢物的种类越来越多地被认为能够影响表观遗传过程， 染色质重塑，包括高度可塑性的染色质结构域，指导关键的转录程序， 保持SC身份。因此，实现更好地理解代谢之间的复杂串扰， 表观遗传学和SC功能是关键，以确定必要的信号级联，以保持SC- 介导的再生能力。为了实现这些目标，小鼠毛囊是一个很好的系统 因为它自然地经历组织稳态和再生的重复和同步循环。 首先，我将分离和纯化毛囊干细胞（HFSC）在静止期，活化期和增殖期的细胞群。 在它们转变为短命的增殖性祖细胞之后。然后我会进行体内代谢分析 通过使用气相色谱-质谱法直接测量代谢物丰度。稳定同位素 示踪将确定代谢物周转率及其来自若干碳源的相对贡献， 包括葡萄糖、脂肪酸和氨基酸谷氨酰胺（Aim I）。接下来，我会设计生物能量 传感器监测HFSC在整个毛发周期和体内生理周期内的代谢动力学， 设置.这将通过利用我的实验室强大而快速的子宫内慢病毒技术来实现， 将这些传感器特异性地传递到皮肤上皮和毛囊（Aim II）。我将应用CRISPR介导的 使用子宫内慢病毒递送平台的敲除策略，以功能性地评估代谢产物的影响。 干扰HFSC的代谢和行为。最后，我将衡量这些 针对HFSC中染色质重塑的关键代谢途径的干预，阐明了 代谢适应在表观遗传转换过程中所起的机械作用 从自我更新到血统承诺和分化（目标III）。总的来说，这项工作将定义功能 再生毛发中代谢重编程的后果和表观遗传机制 卵泡，提供新的治疗靶点，有可能帮助维持长期组织 在受SC不平衡影响的疾病中的稳态，从衰老到癌症。

PROJECT SUMMARY Emerging evidence has uncovered a critical role for cellular metabolism as stem cells (SCs) balance self- renewal and differentiation to maintain tissue homeostasis. However, little is known mechanistically about how SCs integrate metabolic stimuli during cell fate decisions within their in vivo niches. Furthermore, several classes of metabolites are increasingly being recognized as able to influence epigenetic processes that control chromatin remodeling, including highly plastic chromatin domains that direct key transcriptional programs to maintain SC identity. Thus, achieving a better understanding of the complex crosstalk between metabolism, epigenetics and SC function is critical to identify essential signaling cascades necessary to preserve SC- mediated regenerative capacity. To achieve these goals, the murine hair follicle is an excellent system because it naturally undergoes recurrent and synchronous cycles of tissue homeostasis and regeneration. First, I will isolate and purify populations of hair follicle stem cells (HFSCs) during quiescence, activation and following their transition to short-lived, proliferative progenitors. I will then perform in vivo metabolomic profiling by directly measuring metabolite abundance using gas chromatography–mass spectrometry. Stable isotope tracing will determine metabolite turnover rates and their relative contributions from several carbon sources, including glucose sugars, fatty acids and the amino acid glutamine (Aim I). Next, I will engineer bioenergetic sensors to monitor the metabolic dynamics of HFSCs throughout the hair cycle and within in vivo physiological setting. This will be accomplished by exploiting my lab's powerful and rapid in utero lentiviral technology to deliver these sensors specifically to the skin epithelium and hair follicle (Aim II). I will apply CRISPR-mediated knockout strategies using the in utero lentiviral delivery platform to functionally assess the impact of metabolic perturbations to the metabolism and behavior of HFSCs. And finally, I will measure the impact of these interventions aimed at critical metabolic pathways on chromatin remodeling in HFSCs, clarifying the mechanistic contributions played by metabolic adaptations during the epigenetic switch governing the transition from self-renewal to lineage commitment and differentiation (Aim III). In total, this work will define the functional consequences and epigenetic mechanisms underlying metabolic reprogramming in the regenerating hair follicle, providing novel therapeutic targets that have the potential to help maintain long-term tissue homeostasis in diseases affected by SC imbalance, ranging from aging to cancer.