Cell-ECM interactions in the development of the aortic arch arteries

主动脉弓发育中的细胞-ECM 相互作用

• 批准号: 9484520
• 负责人: Sophie Astrof
• 金额: $ 4.14万
• 依托单位: THOMAS JEFFERSON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2020-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9484520
• 关键词: Actins; Address; Alpha Cell; Alternative Splicing; Arteries; Biological; Biomechanics; Blood; Blood Vessels; Branchial arch structure; Cardiac; Cardiovascular system; Cell Culture Techniques; Cell Differentiation Induction; Cell Differentiation process; Cell Nucleus; Cells; Communication; Complement; Complement Factor B; Congenital Abnormality; Cytoplasm; Cytoskeleton; Data; Defect; Development; Embryo; Embryonic Development; Endothelium; Exons; Extracellular Matrix; Fibronectins; Frequencies; Genes; Genetic Transcription; Glycoproteins; Grant; Heart; Human; Hydrogels; Impairment; In Situ Hybridization; In Vitro; Integrin alpha5; Integrin alpha5beta1; Integrins; Interruption; Life; Live Birth; MADH2 gene; Mechanics; Mediating; Messenger RNA; Modeling; Molecular; Molecular Genetics; Morbidity - disease rate; Morphogenesis; Mouse Strains; Mus; Muscle Cells; Mutagenesis; Neonatal; Neural Crest; Neural Crest Cell; Nuclear; Nuclear Translocation; Operative Surgical Procedures; Pathway interactions; Patients; Pattern; Pharmacology; Play; Process; Proteins; RNA Splicing; Rest; Role; Signal Transduction; Smooth Muscle; Source; Stem cells; System; Testing; Tissues; Transforming Growth Factor beta; Trees; Variant; Vascular Smooth Muscle; aortic arch; cell motility; cell type; chemical property; congenital heart disorder; embryo tissue; experimental study; in vivo; insight; mechanical properties; mortality; mutant; myocardin; polymerization; progenitor; public health relevance; receptor; transcription factor

 DESCRIPTION (provided by applicant): Embryonic morphogenesis requires coordinated communications among diverse cell types. Dysregulation of these interactions results in birth defects. Signaling among cells in vivo occurs in the context of the extracellular matrix (ECM), and both the chemical and mechanical properties of the ECM regulate cell signaling and progenitor cell fates. Mechanisms whereby components of the ECM regulate embryonic morphogenesis are not well understood. In the course of the studies supported by our first R01, we made the intriguing discovery that synthesis of the ECM glycoprotein fibronectin (Fn1) is dynamically regulated during mouse embryonic development, and that the expression of Fn1 is highly enriched in distinct embryonic progenitors important for cardiovascular morphogenesis. Fn1 is a highly conserved vertebrate glycoprotein encoded by a single gene in mice and humans, and previous studies showed that Fn1 is required for cardiovascular development. Therefore, we hypothesized that different cellular sources of Fn1 played distinct, biologically significant roles in the development of the cardiovascular system. Preliminary data presented in this grant demonstrate that Fn1 synthesized by the neural crest (NC) is essential for the development of the aortic arch arteries (AAAs), a system of blood vessels that routs oxygenated blood from the heart to the rest of the body. Fn1 mRNA and protein become highly induced in NC cells surrounding the pharyngeal arch arteries as these blood vessels mature into the AAAs, and we show that Fn1 synthesized by NC cells around the pharyngeal arch arteries regulates the differentiation of NC cells into vascular smooth muscle cells (VSMCs). We present evidence suggesting that Fn1 synthesized by the NC regulates NC-to-VSMC differentiation in a cell- autonomous manner by signaling through integrin α5β1 and regulating actin polymerization, which in turn, regulates the translocation of the myocardin-related transcription factor B (MRTFB) from the cytoplasm into the nucleus. In the nucleus, MRTFB can directly activate the transcription of smooth muscle genes, and we show that a deletion mutant of MRTFB that constitutively localizes to the nucleus rescues smooth muscle differentiation in Fn1-deficient NC cells. In this renewal application we propose to determine the mechanisms by which Fn1 regulates NC-to-VSMC differentiation and the role of tissue biomechanics in this process by addressing the following Specific Aims: 1) To test the hypothesis that Fn1 regulates the differentiation of NC cells into VSMCs by signaling through integrin α5β1; 2) To test the hypothesis that Fn1 and tissue biomechanics regulate NC-to-VSMC differentiation by modulating actin cytoskeletal dynamics and nuclear localization of MRTFB; and 3) To test the hypotheses that EIIIA+ and EIIIB+ forms of Fn1 regulate NC-to-VSMC differentiation and that the induction of Fn1 in NC cells surrounding the endothelium of the pharyngeal arch arteries is mediated by SMAD2-dependent signaling.

 描述（由适用提供）：胚胎形态发生需要各种细胞类型之间的协调通信。这些相互作用的失调导致出生缺陷。体内细胞之间的信号传导发生在细胞外基质（ECM）的背景下，ECM的化学和机械性能都调节细胞信号传导和祖细胞命运。 ECM组件调节胚胎形态发生的机制尚不清楚。在我们的第一个R01支持的研究过程中，我们提出了一个有趣的发现，即在小鼠胚胎发育过程中，ECM糖蛋白纤连蛋白（FN1）的合成受到动态调节，并且FN1的表达高度富集在不同的胚胎祖细胞中对心血管形式的不同胚胎祖细胞。 FN1是一种由小鼠和人类单个基因编码的高度保守的脊椎动物糖蛋白，先前的研究表明，FN1是心血管发育所必需的。因此，我们假设FN1的不同细胞来源在心血管系统的发展中起着独特的生物学意义作用。该赠款中提供的初步数据表明，由神经元顶rest（NC）合成的FN1对于主动脉弓动脉（AAAS）的发展至关重要，这是一种使血管从心脏中氧化血液从心脏氧化到身体其余部分的血管系统。当这些血管成熟到AAAS中时，FN1 mRNA和蛋白在咽弓动脉周围的NC细胞中高度诱导，我们表明，咽弓动脉周围NC细胞合成的FN1调节NC细胞的分化为血管平滑肌细胞（VSMCS）。我们提供了证据表明，NC合成的FN1通过通过整合素α5β1发出信号并调节肌动蛋白聚合来调节NC-TO-VSMC分化，从而调节肌动蛋白聚合，从而调节了从细胞质量调节肌蛋白相关转录因子B（MRTFB）的易位。在细胞核中，MRTFB可以直接激活平滑肌基因的转录，我们表明MRTFB的缺失突变体组成性地定位于核挽救FN1缺陷型NC细胞中的平滑肌分化。在此更新应用中，我们建议通过解决以下特定目的来确定FN1调节NC-TO-VSMC分化的机制以及组织生物力学在此过程中的作用：1）测试FN1通过整合蛋白α5β1通过信号传导NC细胞在VSMC中的分化为VSMC的假设。 2）检验假设，即FN1和组织生物力学通过调节肌动蛋白细胞骨架动力学和MRTFB的核定位来调节NC-TO-VSMC分化； 3）为了检验FN1的EIIIA+和EIIIB+形式的假设调节NC-TO-VSMC分化，并且在咽弓动脉内皮的NC细胞中FN1的诱导是由Smad2依赖性信号传导介导的。