Targeting calcification/ stiffness in glaucoma with Matrix Gla

使用 Matrix Gla 治疗青光眼的钙化/僵硬

• 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
• 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

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，残留神经节细胞（RGC）及其轴突退化。一个 这种损伤的重要目标发生在视神经头（ONH）中，RGC轴突离开地球 尽管RGC轴突损伤可能是由不同类型的侮辱造成的，但它是很好的 确定外周胎儿区域（PPSC）的眼内压（IOP）和刚度是主要的 造成这种退化的原因。认为某种分子调节似乎是合乎逻辑的 协调前后受影响的组织对于潜在治疗 青光眼。 以前，我们已经将矩阵GLA（MGP）确定为人类TM中最高表达的基因之一。 我们还发现，IOP，TGFβ和地塞米松在TM中改变了MGP，并且 青光眼患者和MGP-KO小鼠的TM组织中钙化标记的增加。基因 钙化诱导的（BMP2）向大鼠TM的转移也升高了IOP。矩阵GLA是一个有效的 软骨软骨细胞和动脉的血管平滑肌细胞分泌的矿化抑制剂。 MGP 由于大量动脉钙化，KO小鼠在5-6周死亡。动脉钙化导致动脉僵硬 和更高的收缩压。为了研究MGP在眼睛及其的抽象 我们使用了小鼠遗传学对活动物青光眼僵硬症的潜在调节的贡献。到 确定眼睛中的MGP空间/临时表达，我们生成了MGP-CRE敲击（Ki）小鼠， 含有融合到IRES-CRE-COSTETTE的MGP DNA。用R26R-loxed Reporter（LACZ）的小鼠交叉 正如预期的那样 令人惊讶的是，MGP在巩膜中，特别是PPSC高度表达。 基于这些发现，我们建议MGP及其抗计算/抗增强功能代表 唯一影响两个基本青光眼原因的来源，IOP升高和ONH损伤的源。 那， 我们假设MGP是一个主密钥介导者，可防止钙化/ 靶向眼组织的刚度，因此控制了 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-Reporter小鼠（SA＃1）侮辱体内，以覆盖MGP的早期死亡 通过创建TM和PPSC特定条件敲除（CKO）（SA＃2）来评估KO并评估 青光眼表型的特定消融（SA＃3 执行本提案将获得的结果将提供机械理解和 开发联合TM-PPSC疗法所需的知识，这可能会导致全新 青光眼治疗。