The Role of Crypt Fissioning in IBD Ulcer Healing

项目负责人/主要研究者（Barrett，Terrence，A）： 炎症性肠病（IBD）中粘膜愈合的重要性来自临床数据， 证明它是缓解的预测因子1。因此，溃疡愈合预测了治疗预防溃疡的能力。 不必要的临床后遗症（即手术）。不幸的是，许多IBD患者仍然难治性或失去治疗。 对治疗的反应性导致持续性粘膜溃疡。前瞻性儿科研究表明， 线粒体基因表达减少预示溃疡性结肠炎（UC）的不良结局2.这些发现 Kugathasan等人发现线粒体呼吸链的表达增加， 基因预测有利的（B1保护）克罗恩病（CD）的结果3。根据这些结果和我们的 根据我们自己的数据，我们假设IBD慢性溃疡的关键驱动因素是肠功能衰竭， 上皮细胞（IEC）通过产生活性氧来增加线粒体呼吸。我们将这种慢性病 粘膜炎症抑制线粒体呼吸所需的隐窝分裂（在溃疡愈合）， IBD。这一假设将在以下研究中得到检验：目标1。确定影响 线粒体呼吸促进粘膜愈合。这些研究得益于惊人的新颖的方法。 使用VilCre/mTmG/TFAMfl/fl小鼠的数据，其中线粒体呼吸被证明是维持细胞增殖所必需的。 溃疡愈合中的隐窝分裂。在目标2中，我们将确定线粒体的需求- 使用原代人类结肠在IEC隐窝分裂中衍生的ROS。Aim 3研究将确定 慢性炎症对患者溃疡愈合的影响。溃疡的IEC转录组学 将CD和溃疡性结肠炎的边缘与正常溃疡愈合进行比较。正常溃疡愈合 将使用新的活检或活检（Bx/Bx）方法进行询问（IEC将与 初始活检后4- 6天的Bx/Bx部位）。ScRNAseq结果已经表明， Bx/Bx溃疡中的生物发生（PGC 1 β）水平增加，而IBD IEC中的水平下降。总结：研究 将通过询问新的鼠、人、 以及测定线粒体呼吸抑制的影响的体外结肠样培养模型 关于IEC响应（地穴裂变）。这些研究将检验慢性粘膜炎 炎症（如IBD）抑制线粒体呼吸，这阻碍了ROS诱导的呼吸。 PI 3 K信号传导和隐窝分裂。我们的目标是确定治疗靶点，以增强 线粒体呼吸以帮助IBD中的粘膜修复。 OMB编号0925-0001/0002（2018年1月批准至2020年3月31日修订版）页码续页格式页码

Program Director/Principal Investigator (Barrett, Terrence, A): The importance of mucosal healing in inflammatory bowel disease (IBD) derives from clinical data that demonstrate it to be a predictor of remission1. Thus, ulcer healing predicts the capacity for therapies to prevent unwanted clinical sequelae (i.e. surgery). Unfortunately, many IBD patients remain refractory or lose responsiveness to therapies leading to persistent mucosal ulceration. Prospective pediatric studies show that reduced mitochondrial gene expression predict unfavorable outcomes in ulcerative colitis (UC)2. These findings were supported by Kugathasan et al who found that increased expression of mitochondrial respiratory chain genes predicted favorable (B1 protected) Crohn’s disease (CD) outcomes3. Based on these results and our own data, we hypothesize that a critical driver of chronic ulceration in IBD is the failure of intestinal epithelial cells (IEC) to increase mitochondrial respiration with ROS generation. We posit that chronic mucosal inflammation suppresses mitochondrial respiration needed for crypt fissioning (in ulcer healing) in IBD. This hypothesis will be tested in the following studies: Aim 1. Determine the impact of mitochondrial respiration for mucosal healing. These studies benefit from strikingly novel Prelim. Data using VilCre/mTmG/TFAMfl/fl mice where mitochondrial respiration was shown to be required for crypt fissioning in ulcer healing. In Aim 2 we will determine the requirement of mitochondrial- derived ROS in IEC crypt division using primary human colonoids. Aim 3 studies will determine the impact of chronic inflammation on ulcer healing in patients. IEC transcriptomics from ulcer edges from CD and ulcerative colitis will be compared to normal ulcer healing. Normal ulcer healing will be interrogated using a novel biopsy of a biopsy (Bx/Bx) approach (IEC will be isolated from Bx/Bx sites 4-6day after initial biopsies). ScRNAseq results have already shown that mitochondrial biogenesis (PGC1) increases in Bx/Bx ulcers whereas levels drop in IBD IEC. In summary: Studies will investigate the cause of non-healing ulceration in IBD by interrogating novel murine, human and in vitro colonoid culture models of determining the impact of suppressed mitochondrial respiration on IEC responses (crypt fissioning). The studies will test the notion that chronic mucosal inflammation (as in IBD) suppresses mitochondrial respiration which impedes ROS-induced PI3K signaling and crypt fissioning. Our goal is to identify therapeutic targets to allow for enhanced mitochondrial respiration to aide mucosal repair in IBD. OMB No. 0925-0001/0002 (Rev. 01/18 Approved Through 03/31/2020) Page Continuation Format Page