Control of Trabecular Meshwork Cytoskeleton

小梁网细胞骨架的控制

基本信息

批准号：
8691189
负责人：
Donna M Peters
金额：
$ 33.32万
依托单位：
UNIVERSITY OF WISCONSIN-MADISON
依托单位国家：
美国
项目类别：
财政年份：
2006
资助国家：
美国
起止时间：
2006-09-15 至 2018-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8691189
关键词：
Actins Affect African American Anterior Antibodies Aqueous Humor Binding Biological Process Blindness Cell surface Cells Cytoplasmic Tail Cytoskeleton Deposition Dexamethasone Event Eye Family Family suidae General Population Glaucoma Glucocorticoids Goals Grant Guanine Guanine Nucleotide Exchange Factors Immunofluorescence Microscopy Immunoprecipitation Integrin Signaling Pathway Integrins Knock-out Label Lead Measurement Measures Mediating Molecular Conformation Movement Mutation Operative Surgical Procedures Optic Nerve Organ Culture Techniques Pathway interactions Patients Phagocytosis Physiologic Intraocular Pressure Play Primary Open Angle Glaucoma Process Protein Binding Domain Proteins Retinal Ganglion Cells Risk Factors Role Signal Pathway Signal Transduction Site Small Interfering RNA Staphylococcus aureus Steroids Stimulus Testing Tissues Trabecular meshwork structure Uveitis Viral Vector Western Blotting caveolin 1 crosslink filamin inhibitor/antagonist optic nerve disorder overexpression paxillin pressure prevent public health relevance receptor small hairpin RNA stable cell line therapeutic target

项目摘要

DESCRIPTION (provided by applicant): The long-term objective of this grant is to identify how to control avb3 integrin signaling mechanisms in order to develop therapeutic targets to control phagocytosis and outflow facility in glaucoma. The glaucomas, which lead to irreversible loss of retinal ganglion cells, affect approximately 67 million people worldwide. They are commonly associated with elevated levels of intraocular pressure (IOP) due to a reduction in aqueous humor outflow from the trabecular meshwork (TM). One of the major factors that have emerged as an important regulatory mechanism for outflow facility is the actin cytoskeleton. It controls a number of key biological processes involved in maintaining normal outflow facility including contractility, phagocytosis, and matrix deposition. Integrins play a central role in regulating the activity of actin cytoskeleton and our studies suggest that dysregulation of the avb3 integrin may be responsible for some of changes observed during glaucoma including decreased phagocytosis and outflow facility. We propose that this integrin may be chronically activated in glaucoma, especially steroid induced glaucoma during a process called inside-out signaling. Inside-out signaling occurs when a secondary stimulus such as dexamethasone induces the expression, or binding, of intracellular proteins to the cytoplasmic tails of the integrin subunits This binding triggers the active conformation of the integrin. Once this integrin is activated, it would cause a decrease in phagocytosis and outflow facility by triggering a Rac1/Trio pathway that prevents phagocytosis. We plan to test this hypothesis by using an activating antibody to induce the active conformation of avb3 integrin or viral vectors to overexpress an activated avb3 integrin in porcine organ cultured anterior segments. We then plan to determine if expression of this activated avb3 integrin causes a decrease in phagocytosis and outflow facility. We also plan to determine if the Rac1/Trio pathway utilized by avb3 integrin to decrease phagocytosis is involved in the decrease in outflow facility and how dexamethasone treatment causes the activation of the avb3 integrin. Finally, we plan to determine if increases in outflow facility following steroid treatment correlate with the levels of avb3 integrin expression in the TM. These studies should show whether b3 integrin signaling pathway(s) could be involved in steroid induced glaucoma and identify sites along the pathway that we can target to increase outflow facility in the diseased eye.

描述（由申请人提供）：该赠款的长期目标是确定如何控制AVB3整合素信号传导机制，以开发治疗靶标，以控制青光眼的吞噬作用和流出剂。绿哥膜导致视网膜神经节细胞的不可逆转损失，全世界大约有6700万人。由于小梁网（TM）的水性幽默流出降低，它们通常与眼内压（IOP）升高有关。作为流出设施的重要调节机制出现的主要因素之一是肌动蛋白细胞骨架。它控制着维持正常流出设施（包括收缩力，吞噬作用和基质沉积）的许多关键生物学过程。整合素在调节肌动蛋白细胞骨架的活性和我们的研究表明，AVB3整联蛋白的失调可能是由于青光眼期间观察到的一些变化，包括减少的吞噬作用和流出设施。我们建议该整合素可以在青光眼中长期激活，尤其是在称为内而外信号传导过程中类固醇诱导的青光眼。当二次刺激（例如地塞米松）诱导细胞内蛋白与整合素亚基的细胞质尾巴的表达或结合时，就会发生内而外信号传导。一旦激活该整联蛋白，它将通过触发防止吞噬作用的Rac1/三人途径来减少吞噬作用和流出剂。我们计划通过使用激活抗体诱导AVB3整联蛋白或病毒载体的活动构象来检验该假设，以过表达猪器官培养的前段中激活的AVB3整合素。然后，我们计划确定这种激活的AVB3整合素的表达是否会导致吞噬作用和流出剂的降低。我们还计划确定AVB3整联蛋白用于减少吞噬作用的RAC1/三重量途径是否参与流出设施的减少以及地塞米松处理如何引起AVB3整合素的激活。最后，我们计划确定类固醇治疗后流出设施的增加是否与TM中AVB3整联蛋白表达的水平相关。这些研究应表明B3整联蛋白信号通路是否可以参与类固醇引起的青光眼，并识别沿该途径的位点，我们可以靶向以增加患病眼中流出设施。