Development and vascularity of intestinal mesenchyme

肠间质的发育和血管分布

• 批准号: 10735493
• 负责人: Ramesh A Shivdasani
• 金额: $ 44.81万
• 依托单位: DANA-FARBER CANCER INST
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-06-01 至 2028-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10735493
• 关键词: Abbreviations; Acceleration; Actins; Address; Adult; Anatomy; BMP6 gene; Basic Science; Biological Assay; Blood Vessels; Blood capillaries; Bone Morphogenetic Proteins; CD34 gene; CD81 gene; Cell Differentiation Induction; Cell Differentiation process; Cell Line; Cell Maturation; Cell Nucleus; Cell Proliferation; Cells; Censuses; Chromatin; Collection; Colon; Colorectal Cancer; Complement; Consensus; Data; Development; Developmental Biology; Digestive Physiology; Dimensions; Disease; Elements; Embryo; Endoderm; Endothelial Cells; Enterobacteria phage P1 Cre recombinase; Epidermal Growth Factor; Epithelial Cells; Epithelium; Erinaceidae; Estrogen Receptors; FOXL1 gene; Fibroblasts; Foundations; Funding; Future; Gastrointestinal tract structure; Genetic; Genetic Transcription; Growth; Health; Human; Inflammatory Bowel Diseases; Injury; Interleukin-6; Intestines; Investigation; Knowledge; LGR5 gene; Laboratories; Life; Ligands; Maps; Mesenchymal; Mesenchyme; Mesoderm; Mitotic; Modeling; Modernization; Molecular; Motivation; Mus; Muscularis Mucosa; Myofibroblast; PDGFRA gene; Pericytes; Population; Process; Recombinants; Regulatory Element; Reporter; Reporting; Rest; SHH gene; Signal Induction; Signal Transduction; Signaling Protein; Small Intestines; Smooth Muscle; Smooth Muscle Myocytes; Solid; Source; Specific qualifier value; Stereotyping; Stromal Cells; Submucosa; Tamoxifen; Testing; Tissues; Transposase; Villus; Work; XCL1 gene; base; cell assembly; cell type; cofactor; design; developmental plasticity; experimental study; fetal; fetus cell culture; improved; inhibitor; injured; insight; intestinal crypt; intestinal injury; novel; postnatal; prevent; progenitor; reconstitution; repaired; restraint; segregation; self organization; self-renewal; stem cell niche; stem cells; success; tissue repair; transcription factor; transcriptome sequencing; vasculogenesis

Project Summary Adult digestive epithelia depend on adjacent mesenchyme to sustain intestinal stem cells (ISCs) at the crypt base and drive cell maturation at the villus base. Precisely layered cells that provide redundant and partially overlapping “trophic” factors execute these essential polarized functions. Our lab’s contributions to this emerging understanding include deep characterization of small intestine (SI) and colonic mesenchyme, discovery of potent “trophocytes,” a cellular explanation for the crypt BMP signaling gradient, identification of the authentic source of canonical Wnt ligands, and discovery of niche self-organization. Importantly, work from several groups converges on nearly identical consensus cell populations in mouse and human intestines. Strategically localized fractions of the most abundant cells (which express low PDGFRA), including distinct CD81+ trophocytes, represent notable functional niche elements. In the developing gut mesoderm, PDGFRAlo cells seem to give rise to key structural elements, such as different smooth muscle (SM) compartments and unique intestinal capillaries, before the remaining PDGFRAlo cells generate the ISC niche. Against the backdrop of a complete census of adult mesenchymal cells, these findings pave the way to understand their embryonic origins in modern mechanistic terms. This simple but crucial tissue thus offers opportunities to address a broad, fundamental question in developmental biology: How does an embryonic anlage with limited external cell input achieve and retain its adult form? Because injured intestines must reconstitute the mesenchymal compartment, the answers have important implications for understanding and treating ulcerative and other forms of intestinal damage. Prior investigation of signaling in intestinal development elegantly implicates Hedgehog (Hh, from endoderm) and BMP (from mesoderm) in specifying at least SM and endothelial cells (EC), and possibly other compartments, but how these signals elicit distinct cell fates in ostensibly similar progenitors remains unclear. Discrete cell identities reflect opening and closing of thousands of different cis-regulatory elements (CREs); to deconstruct steps that lie between a mesodermal anlage and the functional tissue into which it develops, we propose to study the chromatin basis of SM (Aim 1) and EC (Aim 2) differentiation. We will map mesenchymal ontogeny rigorously with respect to signature CREs for each resident cell type (Aims 1A and 1B), then investigate in primary fetal cell cultures how Hh activity and BMP inhibition together induce the CRE complement necessary for naïve precursors to undergo SM differentiation (Aim 1C). We then ask how the same signals (albeit likely in different forms or concentrations) induce ECs in similar progenitors (Aim 2A). Finally, we propose studies for mechanistic insight into processes designed for intestinal capillary growth to match, but not exceed, resting tissue demands (Aim 2B). Together, this basic science effort aims for fundamental knowledge about a tissue that is critical for intestinal function in resting and injured states.

项目摘要 成体消化上皮依靠邻近的间充质维持肠道干细胞。 在绒毛底部的隐窝和驱动细胞成熟。精确分层的单元，可提供冗余和 部分重叠的“营养”因子执行这些基本的两极分化功能。我们实验室对 这种新兴的理解包括对小肠(SI)和结肠间充质的深入描述， 发现有效的“滋养细胞”，这是对隐窝BMP信号梯度的细胞学解释，鉴定 正则Wnt配体的真实来源，以及利基自组织的发现。重要的是 来自几个小组的研究在小鼠和人类中几乎相同的共识细胞群上汇聚在一起 肠子。战略性地定位了最丰富的细胞的一部分(表达低PDGFRA)， 包括不同的CD81+滋养细胞，代表着显著的功能生态位元素。在发育中的肠子里 中胚层，PDGFRAlo细胞似乎产生了关键的结构元素，如不同的平滑肌 (SM)隔室和独特的肠道毛细血管，在剩余的PDGFRAlo细胞产生 ISC利基市场。在对成人间充质细胞进行全面普查的背景下，这些发现为 用现代力学术语来理解它们的萌芽起源的方法。这个简单但至关重要的组织因此 提供了解决发育生物学中一个广泛的、基本的问题的机会：如何 外周细胞输入有限的胚胎原基能否获得并保持其成体形态？因为受伤了 肠道必须重建间充质隔室，这些答案对 了解和治疗溃疡性和其他形式的肠道损伤。事先对信令进行调查 在肠道发育中，Hedgehog(HH，来自内胚层)和BMP(来自中胚层)优雅地牵连在一起 在指定至少SM和内皮细胞(EC)，以及可能的其他隔室中，但这些如何 在表面上相似的祖细胞中，信号引发不同的细胞命运仍不清楚。离散单元恒等式 反映数千种不同顺式监管要素(CRE)的开启和关闭；解构步骤 位于中胚层原始组织和它发育成的功能组织之间，我们建议研究 SM(目标1)和EC(目标2)分化的染色质基础。我们将绘制间充质个体发育图 严格针对每种驻留小区类型的签名CRE(目标1A和1B)，然后在 原代胎儿细胞培养中HH活性和BMP抑制如何共同诱导Cre补体 幼稚前体经历SM分化所必需的(目标1C)。然后我们问，同样的信号是如何 (尽管可能以不同的形式或浓度)在相似的祖细胞中诱导内皮细胞(目标2A)。最后，我们 提出对肠道毛细血管生长过程的机械洞察研究，以与之相匹配，但 不超过静息组织需求(目标2B)。总而言之，这项基础科学努力的目标是 了解在静息和受伤状态下对肠道功能至关重要的组织。