MMP regulation of stem cell proliferation in the Drosophila ovary

MMP 对果蝇卵巢干细胞增殖的调节

• 批准号: 8428362
• 负责人: Andrea W Page-McCaw
• 金额: $ 7.8万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-05 至 2015-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8428362
• 关键词: Adult; Alleles; Apical; Biology; Caliber; Cancer Biology; Cell Proliferation; Cells; Chimeric Proteins; Cyst; Data; Daughter; Development; Developmental Biology; Drosophila genus; Epithelium; Erinaceidae; Event; Extracellular Matrix; Family; Female; Foundations; Gene Expression; Gene Expression Profile; Genes; Genetic; Goals; Graafian Follicles; Growth; Heparan Sulfate Proteoglycan; Inflammation; Intestines; Lead; Left; Ligands; Lipids; Lipoproteins; Malignant Neoplasms; Matrix Metalloproteinases; Mediating; Modeling; Mus; Organ; Ovary; Pathway interactions; Peptide Hydrolases; Phenotype; Postdoctoral Fellow; Proliferating; Proteins; RNA Interference; Regenerative Medicine; Regulation; Reporter; Reporting; Role; Signal Pathway; Signal Transduction; Site; Skin; Somatic Cell; Stem cells; Systems Analysis; Testing; Tissues; Training; Vertebrates; cell type; daughter cell; egg; experience; extracellular; genetic analysis; mutant; particle; precursor cell; protein transport; public health relevance; research study; smoothened signaling pathway; stem cell fate; tumor progression

DESCRIPTION (provided by applicant): In the Drosophila ovary, developing follicles are composed of somatic follicle cells surrounding germline cysts that will become the egg. The follicle cells derive from somatic stem cells, which give rise to follicle cell precursors, which i turn differentiate into mature follicle cells. It has been reported that the Wnt (Wg) and Hedgehog (Hh) signaling pathways stimulate somatic stem cell proliferation in the Drosophila ovary, as the hyper-activation of these pathways results in excess follicle cells. These signals are produced by cells that are 3-5 cell diameters away from the stem cells, raising the question of how the signals are transported to the responding stem cells. In our continuing studies of the extracellular matrix-degrading MMP family of proteases, we have observed that when Mmp2 function is lost conditionally in adult females, the follicle stem cells over-proliferate in the ovry. This phenotype is consistent with Mmp2 inhibiting the Wg and/or Hh signaling pathway. This R03 proposal describes a small study to determine how Mmp2 regulates somatic stem cell proliferation. In Aim1, we will determine if Wg, Hh, or both pathways are altered, through analysis of genetic interactions and gene expression patterns. In Aim 2, we will determine how Mmp2 mediates long-range signaling over several cell diameters, by asking if Mmp2-GFP is itself transported, and testing candidate transport models including lipid particle transport, HSPG transport, and GPI-anchor mediated transport. We are well situated to perform these studies, as the PI has been investigating Drosophila MMPs for a decade and originally trained in the Drosophila ovary, and the postdoc performing the experiments has experience with stem cell proliferation in the Drosophila ovary. Additionally, our lab is located immediately adjacent t labs that study wnt and hh signaling in vertebrates. Our studies have high significance, as all three of these pathways - MMP, Wg, and Hh - have been implicated in tumor progression, and Wnt signaling is central to stem cell regulation in epithelia such as skin and intestine. Our findings propose a new model that MMPs limit these growth-promoting signals to stem cells. We expect the small study proposed here will lay the foundation for a larger mechanistic analysis of how MMPs regulate stem cell proliferation, in both development and cancer.

描述（由申请人提供）：在果蝇卵巢中，发育中的卵泡由围绕将成为卵子的种系囊肿的体细胞卵泡细胞组成。卵泡细胞源自成体干细胞，产生卵泡细胞前体，然后分化为成熟的卵泡细胞。据报道，Wnt (Wg) 和 Hedgehog (Hh) 信号通路刺激果蝇卵巢中的体干细胞增殖，因为这些通路的过度激活会导致卵泡细胞过多。这些信号是由距离干细胞 3-5 个细胞直径的细胞产生的，这就提出了如何将信号传输到做出反应的干细胞的问题。 在我们对细胞外基质降解 MMP 蛋白酶家族的持续研究中，我们观察到，当成年女性有条件地丧失 Mmp2 功能时，卵泡干细胞在卵巢中过度增殖。该表型与 Mmp2 抑制 Wg 和/或 Hh 信号通路一致。该 R03 提案描述了一项小型研究，以确定 Mmp2 如何调节成体干细胞增殖。在 Aim1 中，我们将通过分析遗传相互作用和基因表达模式来确定 Wg、Hh 或两条途径是否发生改变。在目标 2 中，我们将通过询问 Mmp2-GFP 本身是否被转运，并测试候选转运模型（包括脂质颗粒转运、HSPG 转运和 GPI 锚定介导的转运）来确定 Mmp2 如何介导跨多个细胞直径的长程信号传导。 我们有能力开展这些研究，因为 PI 十年来一直在研究果蝇 MMP，最初是在果蝇卵巢中接受训练，而进行实验的博士后拥有果蝇卵巢中干细胞增殖的经验。此外，我们的实验室紧邻研究脊椎动物 WNT 和 hh 信号传导的实验室。 我们的研究具有重要意义，因为所有这三种途径 - MMP、Wg 和 Hh - 都与肿瘤进展有关，而 Wnt 信号传导对于皮肤和肠道等上皮细胞的干细胞调节至关重要。我们的研究结果提出了一种新模型，即基质金属蛋白酶限制干细胞的这些生长促进信号。我们预计这里提出的小型研究将为更大规模的 MMP 如何调节发育和癌症中干细胞增殖的机制分析奠定基础。