The Role of Autophagy in Intestinal Regeneration

项目摘要/摘要 这些研究的主要目标是发现预防化疗相关肠道损伤的新方法。DOX- 阿霉素是一种化疗药物，用于治疗患者的转移性癌症，通常用于 建立小鼠肠道损伤模型。化疗有许多非靶向副作用，包括炎症。 粘液膜称为粘膜炎。患者通常表现为疼痛、呕吐和腹泻，导致高 发病率。症状的恶化降低了患者对治疗的依从性，并限制了医生对 治疗性化疗剂量。目前还没有有效的治疗方法来减轻粘膜炎，尽管有必要， 关于肠粘膜炎的研究有限。肠道干细胞(ISC)损伤是小鼠的共同特征 各种侮辱造成的肠粘膜损伤。与肠道再生过程有关的通路-- 排除那些推动细胞重塑的因素，如自噬。阿霉素化疗前禁食-- 小鼠的给药已被证明通过激活自噬来保护肠道干细胞免受DNA损伤。 此外，终末分化的潘氏细胞(PC)对损伤具有抵抗力，可以去分化以帮助 重建肠道上皮的完整性。虽然早期的细胞重建机制 允许有丝分裂后的PC恢复到ISC状态是相对未知的，从 其他终末分化细胞类型的获得性可塑性。值得注意的是，自噬的早期激活是一种 在体外将终末分化的成纤维细胞重新编程为多能干细胞的必要步骤。 这些发现突显了自噬在防止损伤和从损伤中恢复方面的重要性。 当保护不可能的时候。本提案的目标1将阐明自噬在保护中的作用 抗阿霉素引起的肠粘膜损伤。首先，自噬诱导药物雷帕霉素将被 给小鼠灌胃，以确定禁食的保护作用是否可以通过刺激Au-Au来模仿。 单单是吞噬。为了提高这些结果的可译性，禁食/自噬在肠道损伤中的作用 肿瘤反应性将在对阿霉素敏感的转移性癌症模型中进行检测。Aim 2将不会- 自噬在PC介导的损伤后肠道再生中的作用。两台个人电脑特有的基因 将产生改良的小鼠模型以确定PC介导的肠道再吞噬是否需要自噬。 一代。该项目的长期目标是产生具有更广泛影响的可概括的突破。 针对上皮损伤引起的各种胃肠道疾病的临床应用。所有的实验都将是 在贝勒医学院进行，在众多核心设施的协助下，拥有最先进的 设备和技术。该项目是内科科学家培训的有力载体，将培养更多的专业人才。 在技术、批判性思维、沟通和指导方面的能力。

Project Summary/Abstract The main goal of these studies is to discover novel ways to prevent chemotherapy-related intestinal injury. Dox- orubicin is a chemotherapy drug administered to treat metastatic cancers in patients and is commonly used to model intestinal injury in mice. Chemotherapy has many off target side effects, including the inflammation of mucus membranes termed mucositis. Patients commonly present with pain, vomiting and diarrhea causing high morbidity. Worsening symptoms reduce patient adherence to treatment and limit physician administration of therapeutic chemotherapy doses. There are no effective therapies to attenuate mucositis, and despite the need, there is limited research on intestinal mucositis. Intestinal stem cell (ISC) damage is a common feature of murine intestinal mucosal damage by various insults. Pathways related to the regenerative process of the intestine in- clude those that drive cellular remodeling, such as autophagy. Fasting prior to doxorubicin chemotherapy ad- ministration in mice has been shown to protect intestinal stem cells from DNA damage by activating autophagy. Furthermore, terminally differentiated Paneth cells (PCs) are resistant to injury and can de-differentiate to help reestablish the integrity of the intestinal epithelium. While the early cellular reconstructive mechanisms that allow post-mitotic PCs to revert to an ISC state are relatively unknown, insights can be extrapolated from the acquired plasticity of other terminally differentiated cell types. Notably, the early activation of autophagy is an essential step in the reprograming of terminally differentiated fibroblasts into pluripotent stem cells invitro. These findings highlight the importance of autophagy in the protection from injury, and the recovery from injury when protection is not possible. Aim 1 of this proposal will elucidate the role of autophagy in the protection against doxorubicin-induced intestinal mucosal damage. First, rapamycin, an autophagy inducing drug, will be administered to mice to determine if the protective effects of fasting can be emulated by the stimulation of au- tophagy alone. To enhance the translatability of these findings the effect of fasting/autophagy on intestinal injury and tumor responsiveness will be examined in a doxorubicin-sensitive metastatic cancer model. Aim 2 will ex- amine the role of autophagy in PC-mediated intestinal regeneration following injury. Two PC-specific genetically modified mouse models will be generated to determine if autophagy is required for PC-mediated intestinal re- generation. The long-term goal of this project is to produce generalizable breakthroughs that have broader im- plications for the gamut of GI medical conditions that result from epithelial damage. All experiments will be conducted at Baylor College of Medicine, with the assistance of numerous core facilities with state-of-the-art equipment and technology. This project is strong vehicle for physician scientist training and will foster profi- ciency in technique, critical thinking, communication and mentorship.