The role of smooth muscle PPAR gamma in neointima formation

平滑肌 PPAR γ 在新内膜形成中的作用

• 批准号: 8650309
• 负责人: Seth Bernat Furgeson
• 金额: $ 13.04万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-04-18 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8650309
• 关键词: 2,4-thiazolidinedione; Affect; Agonist; Alleles; Angioplasty; Animal Model; Anti-Inflammatory Agents; Anti-inflammatory; Antineoplastic Agents; Arterial Injury; Atherosclerosis; Bexarotene; Blood Vessels; Bone Marrow; Bone Marrow Transplantation; CCL2 gene; Cell Proliferation; Cells; Cellular biology; Complication; Contractile Proteins; Data; Drug usage; Family; Galactosidase; Gene Expression; Gene Targeting; Genetic Transcription; Goals; Human; In Vitro; Inflammatory; Injury; Interleukin-6; Knock-out; Knockout Mice; Label; Ligands; Measures; Mediating; Mediator of activation protein; MicroRNAs; Modeling; Morbidity - disease rate; Mus; Nuclear Receptors; PPAR gamma; Peroxisome Proliferator-Activated Receptors; Phenotype; Pioglitazone; Process; Production; Proliferating; Publishing; RXR; Receptor Activation; Relative (related person); Reporter; Response Elements; Role; Signal Pathway; Site; Smooth Muscle; Smooth Muscle Myocytes; Stromal Cell-Derived Factor 1; Testing; Thiazolidinediones; Time; Tissues; Toxic effect; Vascular Diseases; activating transcription factor; base; cell motility; cell type; chemokine; cytokine; design; diabetic; effective therapy; femoral artery; in vivo; macrophage; member; migration; neointima formation; public health relevance; response; restenosis; rosiglitazone

DESCRIPTION (provided by applicant): PROJECT SUMMARY The goal of this project is to define the role of peroxisome proliferator-activated receptor (PPAR)3 activation in neointima formation. Neointima formation occurs frequently after angioplasty and causes significant morbidity; vascular smooth muscle cells (SMCs) are key cells during neointima formation. We will study the effects of two clinically available agents on SMC biology and neointima formation. PPAR3 is a ligand-activated nuclear receptor that has been shown to have beneficial effects on vascular disorders. We will compare the effects of two agents: pioglitazone (activates PPAR3 only) and bexarotene (an RXR agonist which activates PPAR3, PPAR1, PPAR4, LXR, and FXR). Our hypothesis is that PPAR3 activation specifically in smooth muscle cells (SMC) will reduce neointima formation by decreasing resident SMC migration and proliferation as well as SMC-derived chemokine production and subsequent recruitment of bone marrow-derived cells. We believe both pioglitazone and bexarotene will be effective but bexarotene may be more effective due to activation of other nuclear receptors. In Aim One, we will compare the effects of pioglitazone to bexarotene on SMCs. We will measure changes in proliferation, cytokine production, and smooth muscle gene expression. In Aim Two, we will determine if the agents affect levels of microRNAs crucial to maintaining SMC phenotype, such as miR- 143, miR-145, and miR-221. In Aim Three, we will examine the effects of the agents in vivo during femoral artery wire injury. To track recruitment of bone-marrow derived cells to the site of arterial injury, all mice will receive bone marrow transplants from a GFP positive donor. After wire injury, mice will be analyzed at multiple time points. Along with neointima size, we will measure production of chemokines (IL-6, MCP-1, SDF-11, and KC), recruitment of bone marrow-derived cells and macrophages, and cellular proliferation. We also plan to study the role of PPAR3 activation specifically in smooth muscle cells during neointima formation. Using an inducible tissue-specific knockout model, we will deplete PPAR3 in smooth muscle cells after mice have received bone marrow transplants from GFP positive donors. Inducible PPAR3 knockout mice and control mice will receive therapy with either pioglitazone, bexarotene or control and be subjected to femoral artery wire injury. At multiple time points, neointima size will again be measured. All mice used in Aim 3B will have the R26R reporter allele in which smooth muscle cells are labeled with 2-galactosidase. Since we can measure both bone marrow derived and resident SMCs, we will determine the relative contribution each cell type makes to the neointima. We will also be able to determine if PPAR3 specifically in smooth muscle cells mediates the effects of bexarotene or pioglitazone. PUBLIC HEALTH RELEVANCE: PROJECT NARRATIVE Bexarotene and pioglitazone are two clinically used drugs that activate PPAR3. In Aim One, we will test whether both agents can affect smooth muscle cell biology equally and, in Aim Two, we will determine whether the agents can change microRNA levels. In Aim Three, we will determine which agent can reduce neointima size the greatest after wire injury.

项目概述本项目的目的是确定过氧化物酶体增殖物激活受体（PPAR）3激活在新生内膜形成中的作用。新生内膜形成经常发生在血管成形术后，并引起显著的发病率；血管平滑肌细胞（SMCs）是新生内膜形成的关键细胞。我们将研究两种临床可用的药物对SMC生物学和新内膜形成的影响。PPAR3是一种配体激活的核受体，已被证明对血管疾病有有益的作用。我们将比较两种药物的效果：吡格列酮（仅激活PPAR3）和贝沙罗汀（一种激活PPAR3、PPAR1、PPAR4、LXR和FXR的RXR激动剂）。我们的假设是，PPAR3在平滑肌细胞（SMC）中的特异性激活将通过减少驻留SMC的迁移和增殖以及SMC衍生的趋化因子的产生和随后的骨髓来源细胞的募集来减少新内膜的形成。我们相信吡格列酮和贝沙罗汀都是有效的，但贝沙罗汀可能由于其他核受体的激活而更有效。在Aim 1中，我们将比较吡格列酮和贝沙罗汀对SMCs的影响。我们将测量细胞增殖、细胞因子产生和平滑肌基因表达的变化。在Aim 2中，我们将确定这些药物是否影响维持SMC表型至关重要的microrna水平，如miR- 143、miR-145和miR-221。在第三部分中，我们将研究这些药物在股动脉金属丝损伤期间的体内作用。为了追踪骨髓来源细胞在动脉损伤部位的募集，所有小鼠都将接受来自GFP阳性供体的骨髓移植。钢丝损伤后，小鼠将在多个时间点进行分析。随着新内膜的大小，我们将测量趋化因子（IL-6, MCP-1， SDF-11和KC）的产生，骨髓源性细胞和巨噬细胞的募集以及细胞增殖。我们还计划研究PPAR3在新生内膜形成过程中在平滑肌细胞中的特异性激活作用。使用可诱导的组织特异性敲除模型，我们将在小鼠接受来自GFP阳性供者的骨髓移植后，耗尽平滑肌细胞中的PPAR3。诱导型PPAR3基因敲除小鼠和对照组小鼠分别接受吡格列酮、贝沙罗汀或对照组治疗，并进行股动脉丝损伤。在多个时间点再次测量新生内膜大小。所有用于Aim 3B的小鼠都具有R26R报告等位基因，其中平滑肌细胞被标记为2-半乳糖苷酶。由于我们可以测量骨髓源性和常驻SMCs，我们将确定每种细胞类型对新生内膜的相对贡献。我们还将能够确定PPAR3是否特异性地在平滑肌细胞中介导贝沙罗汀或吡格列酮的作用。