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: 10880075
• 负责人: Swapnil K. Sonkusare
• 金额: $ 44.79万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 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 2027-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10880075
• 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; Open-Angle Glaucoma; Oxidants; Oxidation-Reduction; Oxidative Stress; Pathologic; Pathology; Pathway interactions; Perfusion; Peroxonitrite; 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; pharmacologic; 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.

摘要 原发性开角型青光眼(POAG)是导致不可逆视力的最常见的青光眼形式 损失。小梁网(TM)组织功能障碍所致的高眼压(IOP)是 普阿格。然而，导致TM功能障碍和眼压升高的病理机制尚不清楚 明白了。TM有一种内在的能力，通过感知眼压流量的变化来维持眼压的动态平衡 房水(AH)。在这一点上，我们最近发现钙离子通过瞬时受体电位内流 TM中的香草样4离子通道(TRPV4TM通道)通过激活内皮一氧化氮来降低眼压 合酶(ENOS)--NO信号。重要的是，我们发现TRPV4TM-eNOSTM信号在 青光眼原代人TM细胞。这个应用程序的主要目标是阐明 青光眼中损害TRPV4TM-eNOSTM信号的机制及其靶向挽救TM 功能。慢性内质网应激是TM功能障碍和眼压升高的重要因素 青光眼。在我们的初步研究中，我们观察到慢性内质网应激激活诱导型一氧化氮合酶(INOS)，以及 通常与氧化剂分子过氧亚硝酸根(PN)的形成有关的酶。PN水平升高 在POAG供眼的TM组织中，外源性PN降低了人原代TRPV4TM通道的活性 TM细胞。此外，内质网应激的诱导也降低了TRPV4TM通道的活性。因此，我们假设 PN诱导的TRPV4TM-eNOSTM信号抑制导致TM功能障碍和眼压 青光眼眼球抬高。这项应用的主要目标是确定慢性内质网应激 通过PN诱导的TRPV4TM-eNOSTM信号降低导致青光眼TM功能障碍和眼压升高， 并以这种病理为靶点治疗青光眼。在目标1中，我们将确定慢性内质网应激 降低TM细胞的TRPV4通道活性。在目标2中，我们将确定Pn水平是否在 青光眼和PN是否降低TM的TRPV4通道活性。我们还将确定慢性ER是否 压力是青光眼患者PN水平升高的原因。在目标3中，我们将针对PN病理来降低高眼压 高眼压的小鼠和人类模型。这项建议利用了佐德博士的互补专业知识 青光眼研究和内质网应激实验室，以及Sonkusare博士的Trp离子通道成像和 电生理学。这项研究将利用最先进的钙离子成像、膜片钳、eNOS活性和一氧化氮 原代人TM细胞和TM组织、人灌流培养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的病理机制 泛发性开角型青光眼的治疗靶点。