Impaired TRVP4-eNOS signaling in TM contributes to glaucoma

TM 中 TRVP4-eNOS 信号传导受损导致青光眼

• 批准号: 10503094
• 负责人: Swapnil K. Sonkusare
• 金额: $ 44.41万
• 依托单位: UNIVERSITY OF NORTH TEXAS HLTH SCI CTR
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2023-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10503094
• 关键词: Aqueous Humor; Blindness; Cell model; Cells; Chemicals; Chronic; Electrophysiology (science); Enzymes; Eye; Functional disorder; Genetic; Glaucoma; Goals; Homeostasis; Human; Image; Impairment; Ion Channel; Laboratories; Measurement; Molecular; Mus; NOS2A gene; NOS3 gene; Nitric Oxide; Nitric Oxide Synthase; Ocular Hypertension; Oxidants; Oxidation-Reduction; Oxidative Stress; Pathologic; Pathology; Pathway interactions; Perfusion; Peroxonitrite; Pharmacology; Physiologic Intraocular Pressure; Post-Translational Protein Processing; Primary Open Angle Glaucoma; Research; Resistance; Risk Factors; Signal Pathway; Signal Transduction; Techniques; Tissues; Trabecular meshwork structure; Vanilloid; aqueous humor flow; endoplasmic reticulum stress; ex vivo perfusion; human model; improved; inhibitor; innovation; insight; knock-down; mouse model; novel; overexpression; patch clamp; receptor; therapeutic target; transcription factor

Abstract Primary Open Angle Glaucoma (POAG) is the most common form of glaucoma that leads to irreversible vision loss. Elevated intraocular pressure (IOP) due to dysfunction of trabecular meshwork (TM) tissue is a hallmark of POAG. However, the pathological mechanisms leading to TM dysfunction and IOP elevation are poorly understood. TM has an intrinsic ability to maintain IOP homeostasis by sensing the changes in the flow of aqueous humor (AH). In this regard, we recently showed that Ca2+ influx through transient receptor potential vanilloid 4 ion channels in the TM (TRPV4TM channels) lowers IOP via activation of endothelial nitric oxide synthase (eNOS)–NO signaling. Importantly, we showed that TRPV4TM-eNOSTM signaling is impaired in glaucomatous primary human TM cells. The major goals of this application are to elucidate the pathological mechanisms that impair TRPV4TM-eNOSTM signaling in glaucoma and to target them for rescuing the TM function. Chronic endoplasmic reticulum (ER) stress is a crucial contributor to TM dysfunction and IOP elevation in glaucoma. In our preliminary studies, we observed that chronic ER stress activates inducible NOS (iNOS), an enzyme commonly associated with the formation of oxidant molecule peroxynitrite (PN). PN levels are elevated in TM tissues from POAG donor eyes and exogenous PN reduced TRPV4TM channel activity in human primary TM cells. Moreover, induction of ER stress also lowered TRPV4TM channel activity. Therefore, we hypothesize that PN-induced inhibition of TRPV4TM-eNOSTM signaling contributes to TM dysfunction and IOP elevation in glaucoma. The major objectives of this application are to determine whether chronic ER stress leads to TM dysfunction and IOP elevation via PN-induced lowering of TRPV4TM-eNOSTM signaling in glaucoma, and to target this pathology for the treatment of glaucoma. In Aim 1, we will determine whether chronic ER stress lowers TRPV4 channel activity in TM cells. In Aim 2, we will determine whether PN levels are elevated in glaucoma and whether PN lowers TRPV4 channel activity in TM. We will also determine whether chronic ER stress underlies elevated PN levels in glaucoma. In Aim 3, we will target PN pathology to lower elevated IOP in mouse and human models of ocular hypertension. This proposal utilizes complementary expertise of Dr. Zode’s laboratory in glaucoma research and ER stress, and Dr. Sonkusare’s laboratory in TRP ion channel imaging and electrophysiology. This study will utilize state-of-art Ca2+ imaging, patch-clamp, eNOS activity, and nitric oxide measurements in primary human TM cells and TM tissues, human perfusion cultured donor eyes, and mouse models of glaucoma. Successful completion of the proposed studies will provide novel pathological mechanisms and therapeutic targets for the treatment of general POAG.

抽象的 初级开角青光眼（POAG）是最常见的青光眼形式，导致不可逆转的视力 损失。由于小梁网（TM）组织的功能障碍引起的眼内压（IOP）是一个标志 Poag。但是，导致TM功能障碍和IOP升高的病理机制很差 理解。 TM具有通过感知流动的变化来维持IOP稳态的内在能力 水性幽默（啊）。在这方面，我们最近表明Ca2+通过瞬时受体电势影响 TM（TRPV4TM通道）中的香草素4离子通道通过激活内皮一氧化氮而降低IOP 合酶（ENOS） - 无信号传导。重要的是，我们表明TRPV4TM-Enostm信号在 青光眼原代人TM细胞。该应用的主要目标是阐明病理 损害青光眼中TRPV4TM-Enostm信号传导的机制并将其瞄准以营救TM 功能。慢性内质网（ER）应力是导致TM功能障碍和IOP升高的关键因素 在青光眼中。在我们的初步研究中，我们观察到慢性ER应力激活了诱导型NOS（Inos），A 酶通常与氧化物分子过氧亚硝酸盐（PN）的形成有关。 PN水平升高 在POAG供体眼中的TM组织中，外源PN降低了人类原发性的TRPV4TM通道活性 TM细胞。此外，ER应力的诱导还降低了TRPV4TM通道活性。因此，我们假设 PN诱导的TRPV4TM-Enostm信号抑制有助于TM功能障碍和IOP 青光眼升高。该应用程序的主要目标是确定是否慢性ER应力 通过PN诱导的降低TRPV4TM-Enostm信号传导，导致TM功能障碍和IOP升高， 并针对这种病理来治疗青光眼。在AIM 1中，我们将确定是否慢性ER压力 降低TM细胞中TRPV4通道活性。在AIM 2中，我们将确定PN水平是否升高 青光眼以及PN是否降低TM中的TRPV4通道活性。我们还将确定是否慢性ER 压力基础是青光眼中的PN水平升高。在AIM 3中，我们将针对PN病理学以降低IOP的升高 小鼠和人类的眼高血压模型。该建议利用了Zode博士的完整专业知识 青光眼研究和ER压力的实验室，以及Sonkusare博士在TRP离子通道成像中的实验室和 电生理学。这项研究将利用最先进的Ca2+成像，斑块夹，eNOS活性和一氧化氮 原代人TM细胞和TM组织，人灌注培养的供体眼和小鼠的测量 青光眼模型。拟议研究的成功完成将提供新颖的病理机制 和治疗一般POAG的治疗靶标。