Targeting calcification/ stiffness in glaucoma with Matrix Gla

使用 Matrix Gla 治疗青光眼的钙化/僵硬

基本信息

批准号：
9762117
负责人：
Teresa Borras
金额：
$ 33.92万
依托单位：
UNIV OF NORTH CAROLINA CHAPEL HILL
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-08-01 至 2021-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9762117
关键词：
Ablation Adult Affect Age Animals Anterior Antibodies Aqueous Humor Arteries Autopsy Axon BMP2 gene Behavioral Biomechanics Blindness Blood Pressure Breathing CRISPR/Cas technology Calcinosis Cartilage Cell Survival Cessation of life Chondrocytes DNA Development Dexamethasone Disease Elastin Evaluation Extracellular Matrix Eye Gene Transfer Generations Genes Genetic Glaucoma Grant Histologic Human Internal Ribosome Entry Site Knock-in Knock-in Mouse Knock-out Knockout Mice Knowledge Laboratories LacZ Genes Lead Left Link LoxP-flanked allele MGP gene Malignant Neoplasms Mediating Mediator of activation protein Microspheres Modeling Molecular Morphology Mus Open-Angle Glaucoma Optic Disk Optic Nerve Outcome Pathologic Pathway interactions Patients Performance Phenotype Physiologic Intraocular Pressure Physiological Predisposition Process Rattus Regulation Reporter Reporting Resistance Retinal Ganglion Cells Role Sclera Smooth Muscle Myocytes Source Systolic Pressure Technology Testing Tissues Tomatoes Trabecular meshwork structure Transforming Growth Factor beta Transgenic Organisms Vascular Diseases Vascular Smooth Muscle Viral Visual Acuity Visual Fields WNT Signaling Pathway alternative treatment aqueous arterial stiffness axon injury base calcification calcification inhibitor fundus imaging in vivo inhibitor/antagonist interest mineralization optic nerve disorder premature preservation prevent response soft tissue

项目摘要

PROJECT DESCRIPTION During the progression of glaucoma, the retinal ganglion cells (RGC) and their axons degenerate. An important target to this damage occurs in the optic nerve head (ONH), where the RGC axons leave the globe to form the optic nerve. Although RGC axonal damage can be caused by different type of insults, it is well- established that elevated intraocular pressure (IOP) and stiffness in the peripapillary region (ppSC) are major contributors to this degeneration. It would seem logical to think that some kind of molecular regulation coordinating the anterior and posterior affected tissues would be of great benefit for a potential treatment of glaucoma. Previously, we had identified Matrix Gla (MGP) as one of most highly expressed genes in the human TM. We had also found that MGP was altered in the TM by elevated IOP, TGFβ and dexamethasone, and that calcification markers were increased in TM tissues from glaucoma patients and Mgp-KO mice. The gene transfer of a calcification inducer (BMP2) to the rat’s TM also elicited elevated IOP. Matrix Gla is a potent mineralization inhibitor secreted by cartilage chondrocytes and arteries’ vascular smooth muscle cells. Mgp KO mice die at 5-6 weeks due to massive arterial calcification. Arterial calcification results in arterial stiffness and higher systolic blood pressure. In order to investigate the abundance of Mgp in the eye and its contribution to a potential regulation of stiffness in glaucoma in a living animal, we used mouse genetics. To determine the Mgp spatial/ temporal expression in the eye, we generated an Mgp-Cre Knock-in (KI) mouse, containing Mgp DNA fused to an IRES-Cre-cassette. Crosses of this mouse with R26R-floxed reporters (lacZ and td.Tomato) revealed, as expected, Mgp’s high specific expression in the TM region, but also, and surprisingly, Mgp was highly and specifically expressed in the sclera, in particularly the ppSC. Based on these findings, we propose that MGP and its anti-calcification/ anti-stiffness function represents a sole mechanism that affects the source of two basic glaucomatous causes, elevated IOP and ONH damage. Thus, we hypothesize that MGP is a master key-mediator that prevents the occurrence of calcification/ stiffness in the targeted eye tissues, and as a consequence, controls the development and progression of glaucoma. To develop and prove this hypothesis, we propose to investigate the response of Mgp to glaucomatous insults in vivo using the newly generated Mgp-Cre-reporter mice (SA#1), to override the early death of the Mgp KO by creating TM and ppSC specific conditional Knock-outs (cKOs) (SA#2) and to evaluate the impact of the specific ablations on glaucoma phenotypes (SA#3 Results to be obtained with the execution of this proposal will provide the mechanistic understanding and the knowledge needed to develop a combined TM-ppSC therapy which could potentially lead to a totally new treatment of glaucoma.

项目描述在青光眼的进展过程中，视网膜神经节细胞（RGC）及其轴突退化。这种损伤的重要目标发生在视神经乳头 (ONH)，RGC 轴突离开眼球的地方虽然 RGC 轴突损伤可能是由不同类型的损伤引起的，但它是很好的。确定眼压 (IOP) 升高和视乳头周围区域 (ppSC) 僵硬是主要原因认为某种分子调节是导致这种退化的因素似乎是合乎逻辑的。协调前部和后部受影响的组织对于潜在的治疗有很大好处青光眼。此前，我们已确定 Matrix Gla (MGP) 是人类 TM 中表达最高的基因之一。我们还发现，TM 中的 MGP 因 IOP、TGFβ 和地塞米松升高而发生改变，并且青光眼患者和 Mgp-KO 小鼠的 TM 组织中钙化标志物基因增加。将钙化诱导剂 (BMP2) 转移至大鼠的 TM 也会引起眼压升高，Matrix Gla 是一种有效的药物。由软骨软骨细胞和动脉血管平滑肌细胞分泌的矿化抑制剂。 KO 小鼠在 5-6 周时因大量动脉钙化而死亡。动脉钙化导致动脉僵硬。和较高的收缩压，以研究眼睛中 Mgp 的丰度及其含量。为了对活体动物青光眼僵硬的潜在调节做出贡献，我们使用了小鼠遗传学。确定眼睛中的 Mgp 空间/时间表达，我们生成了 Mgp-Cre 敲入 (KI) 小鼠，含有与 IRES-Cre 盒融合的 Mgp DNA 该小鼠与 R26R-floxed 生产者 (lacZ) 的杂交。和 td.Tomato）如预期的那样揭示了 Mgp 在 TM 区域的高特异性表达，而且，令人惊讶的是，Mgp 在巩膜中高度特异性表达，尤其是 ppSC。基于这些发现，我们认为 MGP 及其抗钙化/抗僵硬功能代表了影响两种基本青光眼病因（眼压升高和 ONH 损伤）根源的唯一机制。因此，我们追求MGP是防止钙化发生的关键介质/ 目标眼组织的僵硬，因此控制了眼部疾病的发展和进展青光眼。为了发展和证明这一假设，我们建议研究 Mgp 对青光眼的反应使用新生成的 Mgp-Cre 报告小鼠 (SA#1) 进行体内损伤，以覆盖 Mgp 的过早死亡通过创建 TM 和 ppSC 特定条件性敲除 (cKO) (SA#2) 来进行 KO，并评估其影响针对青光眼表型的特异性消融（SA#3 执行本提案所获得的结果将提供机制上的理解和开发 TM-ppSC 联合疗法所需的知识，这可能会带来一种全新的疗法青光眼的治疗。