Identifying the role of serotonin receptor 4 and trefoil factor 3 in intestinal wound repair

项目总结 背景与目的：5-羟色胺(5-羟色胺)通过多种途径在胃肠道发挥多种生理功能。 激活14种不同的5-羟色胺受体亚型。升高的5-羟色胺水平是对组织的反应 损伤，表明5-羟色胺的释放可能介导了重要的修复机制。5-羟色胺被证明 对皮肤损伤和胃溃疡有修复作用，5-羟色胺受体4(5-HTR4)具有特异性 已被证明在结肠组织损伤后具有抗溃疡作用。然而，这背后的机制 这一现象尚不清楚。最近，已经在杯状细胞上发现了5-HTR4，这种细胞已知能产生三叶草 因子3(TFF3)；肠道修复中的关键化合物。目前，5-HTR4和TFF3之间的联系尚不清楚。 使用人类肠道类产生的初步数据表明，外源性5-羟色胺 在实时成像伤口愈合分析中刺激TFF3释放以促进修复。这一影响通过以下措施得到缓解 抑制TFF3受体CXCR4。在以微生物为中心的方法中，我们的实验室还发现了一种 共生细菌牙双歧杆菌，在共生菌小鼠、小鼠和人的肠道中 能够刺激肠嗜铬细胞释放5-羟色胺。此外，治疗人类肠样病变 在伤口愈合试验中，牙本质代谢物也能促进上皮修复，类似于外源性。 血清素。这一提议的总体假设是，5-羟色胺激活杯状细胞上的5-HTR4以刺激 TFF3的释放，作用于其受体CXCR4，介导负责上皮修复的信号级联反应。 目的1利用小鼠模型确定TFF3对5-HTR4介导的在体上皮修复的需求 以及结肠镜检查导致的结肠伤口。目标2试图研究一种微生物刺激方法 体内5-羟色胺的产生与伤口愈合。最后，Aim 3解决了以下方面所需的信令级联 TFF3对体外培养的小鼠和人结肠上皮细胞的修复作用。粘膜 治愈是治疗溃疡、外科吻合口、肠皮肤瘘和炎性疾病的关键。 肠道疾病的伤口。伤口愈合不好会导致并发症，包括感染、延长 住院治疗和危重疾病。长期目标和目标：我的长期目标是成为一名富有成效的 研究机构的独立调查员。获得K01职业发展奖将更好地装备我 来实现这一目标。我的研究非常适合国家糖尿病和消化与肾脏研究所 疾病，因为它与肠道伤口修复有关。我目前的机构，贝勒医学院，提供科学的 完成此提案所需的资源。此外，我召集了一群著名的科学家为 在我的导师委员会和微生物学和伤口修复领域的领导人担任我的导师。在……里面 与我的导师合作，我制定了一个培训计划，使我能够掌握先进的科学 技术，增加我的出版记录，并获得独立的资金。在完成这个奖项时，我相信 我将拥有过渡到独立原则调查员所需的资源和专业知识。

PROJECT SUMMARY Background and aims: Serotonin (5-HT) exerts numerous physiological functions in the gastrointestinal tract via activation of 14 different serotonin receptor subtypes. Elevated serotonin levels are noted in response to tissue damage, indicating that serotonin release may mediate important repair mechanisms. Serotonin has been shown to have reparative effects on skin injury and gastric ulcers, and serotonin receptor 4 (5-HTR4) specifically has been shown to have anti-ulcerogenic action after colon tissue damage. However, the mechanism behind this phenomenon is unclear. Recently 5-HTR4 has been identified on goblet cells, which are known to produce trefoil factor 3 (TFF3); a key compound in intestinal repair. Currently the link between 5-HTR4 and TFF3 is unknown. Preliminary data generated using human intestinal enteroids has demonstrated that exogenous serotonin stimulates TFF3 release to promote repair in live imaging wound healing assays. This effect was mitigated by inhibition of the TFF3 receptor CXCR4. In a microbial-centered approach, our lab has also identified a single commensal bacterium, Bifidobacterium dentium, which in gnotobiotic mice and in mouse and human enteroids is able to stimulate serotonin release from enterochromaffin cells. Additionally, treatment of human enteroids with B. dentium metabolites also enhance epithelial restitution in a wound healing assay, similar to exogenous serotonin. The overall hypothesis of this proposal is that serotonin activates 5-HTR4 on goblet cells to stimulate TFF3 release, which acts on its receptor CXCR4 to mediate signaling cascades responsible for epithelial repair. Aim 1 seeks to define the requirement of TFF3 for 5-HTR4 mediated epithelial repair in vivo using mouse models and colonoscopy-induced colonic wounds. Aim 2 seeks to examine a microbial approach for stimulating serotonin production and wound healing in vivo. Finally, Aim 3 addresses the signaling cascade required for TFF3 mediated restitution in intestinal epithelial cells in mouse and human colonic enteroids in vitro. Mucosal healing is critical for in the treatment of ulcers, surgical anastomoses, enterocutaneous fistulae and inflammatory bowel disease wounds. Failure to properly heal wounds can result in complications including infection, prolonged hospitalization, and critical illness. Long-term objective and aims: My long-term goal is to become a productive independent investigator at research institution. Receiving a K01 Career Development Award would better equip me to achieve this goal. My research is well suited for the National Institute of Diabetes and Digestive and Kidney Diseases as it relates to intestinal wound repair. My current institution, Baylor College of Medicine, offers the scientific resources required to complete this proposal. Additionally, I have assembled a group of renowned scientists to serve on my mentorship committee and leaders in the fields of microbiology and wound repair to serve as my mentors. In collaboration with my mentors, I have developed a training plan that will allow me master advanced scientific techniques, increase my publication record and secure independent funding. At the completion of this award, I believe I will have the resources and expertise required to transition to an independent principle investigator.