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.

项目概要 成体消化上皮依靠邻近的间质来维持肠干细胞（ISC） 隐窝基部并驱动绒毛基部的细胞成熟，提供冗余和精确的分层细胞。 部分重叠的“营养”因子执行这些基本的极化功能。 这种新兴的理解包括小肠（SI）和结肠间质的深入表征， 有效“滋养细胞”的发现、隐窝 BMP 信号梯度的细胞解释、鉴定 经典 Wnt 配体的真实来源，以及利基自组织的发现 重要的是， 多个小组的工作集中在小鼠和人类中几乎相同的共有细胞群上 肠道中最丰富的细胞（表达低 PDGFRA）的策略性局部部分， 包括不同的 CD81+ 滋养细胞，代表功能性生态位元素。 中胚层，PDGFRAlo 细胞似乎产生关键的结构元件，例如不同的平滑肌 (SM) 隔室和独特的肠毛细血管，然后剩余的 PDGFRAlo 细胞产生 在对成人间充质细胞进行全面普查的背景下，这些发现为 ISC 利基铺平了道路。 因此，我们可以用现代机械学术语来理解它们的胚胎起源。 提供了解决发育生物学中广泛而基本的问题的机会： 外部细胞输入有限的胚胎原基达到并保留其成年形式？因为受伤？ 肠道必须重建间充质室，这个答案对于 了解和治疗溃疡性和其他形式的肠道损伤。 在肠道发育中，Hedgehog（Hh，来自内胚层）和 BMP（来自中胚层） 至少指定 SM 和内皮细胞 (EC)，以及可能的其他区室，但这些如何 信号在表面上相似的祖细胞中引发不同的细胞命运仍不清楚。 反映数千个不同的顺式监管元素（CRE）的打开和关闭以解构步骤； 位于中胚层原基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。 严格考虑每种驻留细胞类型的特征 CRE（目标 1A 和 1B），然后进行调查 原代胎儿细胞培养物 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）然后我们问相同的信号如何发出。 （尽管可能以不同的形式或浓度）在相似的祖细胞中诱导 EC（目标 2A）。 对过程的机制洞察的研究提出肠道毛细血管的生长相匹配，但是 不超过静息组织的需求（目标 2B），这项基础科学工作旨在实现根本性目标。 关于在休息和受伤状态下对肠道功能至关重要的组织的知识。