REGULATION OF ATROPHY-INDUCED PROGENITOR CELLS IN THE GASTRIC CORPUS

胃体中萎缩诱导的祖细胞的调节

• 批准号: 8695339
• 负责人: Jason C Mills
• 金额: $ 33.05万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-11 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8695339
• 关键词: Ablation; Acids; Adult; Affect; Age; Animals; Arthritis; Atrophic; Bioinformatics; Biological Assay; Blood; CD44 gene; Cancer Etiology; Cell Death; Cell Differentiation process; Cell Proliferation; Cell Surface Proteins; Cells; Cessation of life; Characteristics; Chronic; Data; Databases; Developing Countries; Disadvantaged; Disease; E-Cadherin; Epithelial; Epithelial Cells; Epithelium; Estrogens; Frequencies; Gastric Parietal Cells; Gastric ulcer; Gene Expression; Generations; Genes; Goals; Hematopoietic stem cells; Homeostasis; Hour; Human; Hyaluronan; Inflammation; Inflammatory; Injection of therapeutic agent; Injury; Intestines; Kinetics; Label; Learning; Ligands; Malignant Neoplasms; Mediator of activation protein; Metaplasia; Minority; Molecular; Molecular Genetics; Molecular Profiling; Mus; Organ; Pathway interactions; Patients; Pattern; Pharmaceutical Preparations; Pharmacologic Substance; Phosphorylation; Physiological; Population; Process; Pyloric antrum; Regulation; Relative (related person); Research; Risk; Role; STAT3 gene; Secondary to; Selective Estrogen Receptor Modulators; Signal Transduction; Site; Staging; Stem cells; Stomach; Stomach Diseases; System; Tamoxifen; Techniques; Time; Tissues; Toxic effect; Tweens; Undifferentiated; United States; Work; adult stem cell; cancer risk; cell behavior; cost; genetic pedigree; human disease; inhibitor/antagonist; innovation; killings; laser capture microdissection; malignant stomach neoplasm; progenitor; prospective; research study; response; response to injury; stem; stem cell differentiation; stem cell niche; stem cell population; transcription factor; transcriptome sequencing

DESCRIPTION (provided by applicant): Despite recent breakthroughs in identifying prospective stem cell markers (e.g., LGR5) in the intestines and the gastric antrum, relatively little is known about the stem cells of the gastric (body) corpus epithelium. Our overall goal is t better characterize the corpus stem cell under normal conditions and in response to injury. Preliminary data show that the selective estrogen receptor modulator tamoxifen causes ablation of nearly all parietal cells, the acid-secreting lineage, in the mouse stomach within 3 days. Within 6 hours, parietal cells begin to die (atrophy), and progenitor cells in the isthmal stem cel niche of corpus gastric units begin to expand in response. We further find that: 1) the cell surface protein CD44 is required for normal stem cell homeostasis, because proliferation is halved in Cd44-/- relative to wildtype mice; and 2) CD44 marks the expanding isthmal progenitor population. CD44 activates STAT3 and is induced by ERK signaling. We show here that ERK and STAT3 are activated in early expanding progenitors, and levels of the ERK-induced transcription factor EGR1 peak at 3 days, in concert with maximal progenitor expansion. We hypothesize that parietal cell death leads to signals that activate the ERK pathway in isthmal stem/progenitor cells, which causes increased CD44 expression and increased proliferation. In Aim 1, we will determine whether ERK signaling is required for normal stem cell homeostasis and atrophy-induced expansion using both ERK pharmacological inhibition and pedigrees of mice with deficient (Egr1-/-) and overactive (Nab2-/-) ERK. In Aim 2, we will determine whether CD44 is required or sufficient for atrophy-induced progenitor expansion. We will examine kinetics of stem cell expansion in Cd44-/- mice, and we will either activate CD44 in wildtype mice ¿tamoxifen by injection of the CD44 ligand Hyaluronan or block CD44- Hyaluronan interactions with the inhibitor PEP-1. We will determine if CD44 induces STAT3 and/or if it is required for progenitor expansion. In Aim 3, we will isolate vehicle- and tamoxifen-treated CD44-expressing epithelial progenitor cells by FACS and laser-capture microdissection and then use RNA-Seq to generate gene expression profiles of the normal and atrophy-expanded progenitor cells that will then be integrated bioinformatically with our existing database of global gene expression in stem and progenitor cells. We will also perform limiting dilution assays to determine the stem cell frequency within the epithelial CD44 population. In humans, chronic inflammation can cause parietal cell atrophy, which in turn changes stem cell proliferation and differentiation. Atrophy predispose patients to gastric cancer, but changes in stem cells secondary to inflammation/injury are also an important and understudied aspect of adult diseases in multiple other tissues (e.g., hematopoietic stem cell differentiation changes in arthritis). Thus, the experiments proposed may help us begin to understand stem cell response to injury in multiple tissues and diseases. Finally, our new finding that the key drug tamoxifen causes gastric toxicity warrants further study in humans.

描述（由适用提供）：尽管最近在识别肠和胃胃肠道中识别前瞻性干细胞标记物（例如LGR5）方面取得了突破，但对胃（身体）上皮细胞的干细胞知之甚少。我们的总体目标是更好地表征正常条件下的血管干细胞，并响应损伤。初步数据表明，选择性雌激素受体调节蛋白莫昔芬会在3天内在小鼠摊位中消融几乎所有顶叶细胞，分泌酸的谱系。在6小时内，顶壁细胞开始死亡（萎缩），胃胃单位的地峡茎状细胞中的祖细胞开始随着响应而扩大。我们进一步发现：1）正常干细胞稳态需要细胞表面蛋白CD44，因为相对于野生型小鼠，CD44 - / - 一半的增殖； 2）CD44标志着扩大的地峡祖细胞种群。 CD44激活STAT3，并由ERK信号传导诱导。我们在这里表明，ERK和STAT3在早期扩张的祖细胞中被激活，以及ERK诱导的转录因子EGR1峰的水平，与最大的祖细胞扩张一致。我们假设壁细胞死亡会导致信号，这些信号会激活地峡茎/祖细胞中的ERK途径，这会导致CD44的表达增加，并且在AIM 1中，我们将确定是否需要使用ERK Pharmace抑制剂和defipivivivivivivivivivivivivivivivivivivivivive（n ab）（n ab）（n ab）（n ab）。 ERK。在AIM 2中，我们将确定CD44是否需要或足以用于萎缩诱导的祖细胞扩张。我们将检查CD44 - / - 小鼠干细胞扩展的动力学，我们要么通过注射CD44配体透明质酸，要么在野生型小鼠中激活CD44，或者要么通过抑制剂PEP-1的CD44配体透明质酸或块CD44-透明质酸相互作用来激活CD44。我们将确定CD44是否诱导STAT3和/或是否需要祖细胞扩展。在AIM 3中，我们将通过FACS和激光捕获显微放置进行媒介物和他莫昔芬处理的CD44表达上皮过程细胞，然后使用RNA-SEQ来生成正常和萎缩型expentit剂细胞的基因表达谱，然后将Bio-Ecentitor细胞与我们现有的基因分析酶进行整合，并将其与我们现有的基因酶进行整合。我们还将执行极限稀释测定，以确定上皮CD44种群中的干细胞频率。在人类中，慢性炎症会导致顶叶细胞萎缩，从而改变干细胞的增殖和分化。萎缩患者患胃癌的患者，但继发于炎症/损伤的干细胞的变化也是其他多种组织中成人疾病的重要方面（例如，造血性干细胞分化关节炎的变化）。这就是提出的实验可能有助于我们开始理解多种组织和疾病损伤的干细胞反应。最后，我们的新发现，即他莫昔芬会导致胃毒性导致人类进一步研究。