The role of enteroendocrine cell differentiation in the success of bariatric surgery

项目摘要： 研究减肥手术成功的机制的最重要原因之一是， 用非侵入性治疗复制手术结果。垂直袖状胃切除术（VSG）， 在世界上经常进行减肥手术，结果在大量的体重减轻和戏剧性的缓解 1年内的T2 DM餐后肠道分泌肽水平的急剧增加，如 胰高血糖素样肽-1（GLP-1）、胃抑制多肽（GIP）、肽YY（PYY）和胆囊收缩素 (CCK)在VSG被假设为手术成功的关键机制之后， 在饱腹感和葡萄糖稳态方面。肠肽是在肠上皮中产生的，我们（和其他人） VSG增加了分泌GLP-1的肠内分泌细胞（EEC）的数量。我们希望的一个关键问题是 要解决的是什么驱动VSG后的EEC分化，这种EEC分化是否限于GLP-1， 1-分泌细胞或其他内皮细胞，以及这种增加是否有助于减肥和改善 葡萄糖稳态与VSG。我们的初步数据表明，VSG明确改变肠道 干细胞（ISC）表达几个基因，调节肠道分泌细胞的发展，包括EEC 分化使用一种新的肠道类器官模型（类肠体），我们接下来证明了特异性 胆汁酸的亚种增加分泌GLP-1的EEC。因此，我们假设胆汁中的增加 VSG后的酸分泌影响ISC向EEC的命运，这对减肥手术结果至关重要。 在这里，我们提出了一个互补的体外和体内研究的组合，使用人类和小鼠 拟小肠和小鼠遗传操作与VSG手术的测试有以下具体目的：1）测试 胆汁酸驱动EEC分化假设; 2）检验ISC命运调节影响身体的假设 体重和葡萄糖稳态; 3）测试假设，增加EEC分化是必要的VSG 结果。这项研究计划有望对ISC的理解做出重大贡献 体内平衡，并确定手术诱导的肠肽水平增加的起源， 最终目标是开发减肥手术的替代策略。在资助期间，桑多瓦尔博士， 他是内分泌学和减肥手术方面的专家，将提供卓越的研究环境， 资源在科罗拉多大学安舒茨医学院，并提供研究指导 战略，赠款写作，实验室管理，网络和通信。Inge，Dempsey（CU）， 萨缪尔森，斯宾塞（UM）和Sethupathy（康奈尔大学），谁是减肥手术的专家， 发育和/或干细胞生物学，将提供额外的指导和培训活动，详细信息见 职业发展活动。成功实现目标将使我成为NIH资助的独立研究人员。 研究VSG机制的研究人员以非侵入性策略重现其手术益处， 肥胖症和T2 DM的治疗。

Project Abstract: One of the most prominent reasons to study the mechanisms underlying the success of bariatric surgery is to replicate surgery outcomes with non-invasive treatment(s). Vertical sleeve gastrectomy (VSG), one of the most frequently performed bariatric surgeries in the world, results in substantial weight loss and dramatic remission of T2DM within 1 year. The drastic postprandial increase in the levels of gut-secreted peptides, such as glucagon-like peptide-1 (GLP-1), gastric inhibitory polypeptide (GIP), peptide YY (PYY), and cholecystokinin (CCK), after VSG has been hypothesized to be a critical mechanism of surgical success because of their roles in satiety and glucose homeostasis. The gut-peptides are made in the intestinal epithelium, and we (and others) see that VSG increases the number of GLP-1-secreting enteroendocrine cells (EEC). A key question we wish to address is what drives the EEC differentiation after VSG, whether this EEC differentiation limited to the GLP- 1-secreting cells or the other EECs, and whether this increase contributes to weight loss and improvements in glucose homeostasis seen with VSG. Our preliminary data demonstrate that VSG alters explicitly intestinal stem cell (ISC) expression of several genes that regulate intestinal secretory cell development including EEC differentiation. Using a novel intestinal organoid model (enteroids), we next demonstrated that specific subspecies of bile acids increase the GLP-1-secreting EECs. Hence, we hypothesize that the increased in bile acid secretion after VSG impacts the ISC fate towards EECs and this is critical to bariatric surgery outcomes. Here, we propose a combination of complementary in vitro and in vivo studies using human and mouse enteroids and mouse genetic manipulation with VSG surgery to test the following specific aims: 1) test hypothesis that bile acids drive EEC differentiation; 2) test hypothesis that modulation of ISC fate affects body weight and glucose homeostasis; 3) test hypothesis that increased EEC differentiation is necessary for VSG outcomes. This research plan is expected to make a significant contribution to the understanding of ISC homeostasis and to determine the origin of the surgery-induced increase in gut-peptides levels with the ultimate goal of developing an alternative strategy to bariatric surgery. During the grant period, Dr. Sandoval, who is an expert in endocrinology and bariatric surgery, will provide an exceptional research environment and resources at the University of Colorado Anschutz Medical Campus and also provide guidance in research strategy, grant writing, lab management, and networking and communication. Drs. Inge, Dempsey (CU), Samuelson, Spence (UM) and Sethupathy (Cornell University), who are experts in bariatric surgery, developmental and/or stem cell biology, will provide additional guidance and training activities as detailed in the Career development activity. Successfully achieved aims will lead me to a NIH-funded independent researcher studying the mechanism of VSG to reproduce its surgical benefits with a non-invasive strategy in the treatment the obesity and T2DM within a medical sciences department.