Regulation of pHi and Fluid Flux in Corneal Endothelium

角膜内皮 pHi 和液体流量的调节

• 批准号: 9893877
• 负责人: Joseph Aurelio Bonanno
• 金额: $ 42.53万
• 依托单位: TRUSTEES OF INDIANA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-07-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9893877
• 关键词: Active Biological Transport; Address; Aging; Apical; Aqueous Humor; Basic Science; Bicarbonates; Buffers; Carbon Dioxide; Cell Survival; Cell Volumes; Cells; Chimeric Proteins; Cornea; Corneal Endothelium; Corneal dystrophy; Corneal edema; Coupled; Coupling; Data; Distress; Drops; Endothelial Cells; Endothelium; Engineering; Fluorescence Resonance Energy Transfer; Fuchs' Endothelial Dystrophy; Glucose; Goals; HIF1A gene; Human; Hydration status; Hypoxia; Hypoxia Inducible Factor; In Vitro; Inflammation; Ion Transport; Ions; Keratoplasty; Knockout Mice; Knowledge; Lactic acid; Link; Liquid substance; Measures; Medical; Membrane; Mitochondria; Modeling; Mus; Na(+)-K(+)-Exchanging ATPase; Oryctolagus cuniculus; Pathway interactions; Patients; Perfusion; Permeability; Physiological; Production; Property; Protein Isoforms; Pump; Reactive Oxygen Species; Regulation; Reporter; Running; Site; Subfamily lentivirinae; System; Testing; Transplantation; Trauma; Vision; Water; Work; anterior chamber; base; carbonate dehydratase; corneal epithelium; design; experimental study; in vitro testing; in vivo; knock-down; mitochondrial dysfunction; monolayer; sensor; small hairpin RNA; therapy development

There are three major goals of this project period: 1) to demonstrate that the corneal endothelial PUMP is based on Lactate-Water coupled transport, 2) to determine the detailed physiological mechanism for the Lactate-Water coupled system, and 3) to begin to use this basic science knowledge to reverse corneal edema in Endothelial Dystrophy. The PUMP maintains corneal hydration and transparency. When the PUMP fails due to trauma, inflammation, ageing, or corneal dystrophy, corneal edema ensues, transparency is lost and vision is significantly degraded. The usual therapy is transplantation, which is not without significant compromises and complications. Knowing how the PUMP works is one approach to developing medical therapies that could delay or supplant the need for transplantation. Ion transport is a key feature of the PUMP. Over the previous 5-7 years we have provided strong evidence that the PUMP works by transporting lactate ions from the stroma to the anterior chamber. This lactate flux is facilitated by cellular and aqueous humor buffering power from CO2/HCO3- and the carbonic anhydrase system. Our data indicate that water flux is directly linked with lactate flux. We hypothesize that the endothelial cells create a standing [lactate] gradient that drives water osmotically from the stroma to the anterior chamber. Secondly, we show that lactate transport is compromised in a model of endothelial dystrophy. Therefore, we propose that enhancing lactate flux can reduce corneal edema in endothelial dystrophies. Using multiple in vitro, in vivo & ex vivo complementary approaches this will be tested in three aims. Aim #1 will provide experimental conditions that fill gaps in the evidence so that we can confirm the hypothesis that lactate flux, facilitated by active transport mechanisms, is the major contributor to the corneal endothelial PUMP. Aim 2 will determine the mechanism for coupling fluid flux to lactate flux by testing the hypothesis that a transendothelial [lactate] standing-gradient is present and examine the alternate hypothesis that water flux is linked directly to monocarboxylate cotransporter (MCT) flux. Aim 3 will test the hypothesis that Endothelial PUMP function, in normal and distressed cells, can be enhanced via Hypoxia Adaptation. If this hypothesis is correct, it will have the potential to be tested as a therapy for Fuchs Dystrophy.

该项目期间有三个主要目标：1）证明角膜内皮细胞 PUMP基于乳酸-水耦合运输，2）确定详细的生理 乳酸-水耦合系统的机制，以及 3) 开始使用这一基础科学 逆转内皮营养不良中角膜水肿的知识。 PUMP 维持角膜 水合作用和透明度。当泵因外伤、炎症、老化或 角膜营养不良，角膜水肿，透明度丧失，视力明显下降 退化了。通常的治疗方法是移植，这并非没有重大妥协 和并发症。了解泵的工作原理是开发医疗技术的一种方法 可以延迟或取代移植需要的疗法。离子传输是一个关键特征 泵的。在过去的 5-7 年里，我们提供了强有力的证据表明 PUMP 通过将乳酸离子从基质运输到前房来发挥作用。该乳酸通量为 由 CO2/HCO3- 和碳酸的细胞和房水缓冲能力促进 脱水酶系统。我们的数据表明水通量与乳酸通量直接相关。我们 假设内皮细胞产生驱动水的固定[乳酸]梯度 从间质渗透到前房。其次，我们表明乳酸转运是 在内皮营养不良模型中受到损害。因此，我们建议增强乳酸 通量可以减少内皮营养不良的角膜水肿。使用多种体外、体内和前 vivo 的互补方法将在三个目标上进行测试。目标#1将提供 填补证据空白的实验条件，以便我们可以证实以下假设： 由主动运输机制促进的乳酸通量是角膜的主要贡献者 内皮泵。目标 2 将通过以下方式确定流体通量与乳酸通量耦合的机制： 测试存在跨内皮[乳酸]常压梯度的假设并检查 另一种假设是水通量与单羧酸协同转运蛋白直接相关 (MCT) 通量。目标 3 将检验内皮泵功能的假设，在正常和 受损的细胞可以通过缺氧适应来增强。如果这个假设是正确的，那么将会 有潜力作为福克斯营养不良症的治疗方法进行测试。

项目成果

Molecular mechanisms underlying the corneal endothelial pump.

• DOI: 10.1016/j.exer.2011.06.004
• 发表时间: 2012-02
• 期刊: EXPERIMENTAL EYE RESEARCH
• 影响因子: 3.4
• 作者: Bonanno, Joseph A.

Intracellular pH regulation in fresh and cultured bovine corneal endothelium. II. Na+:HCO3- cotransport and Cl-/HCO3- exchange.

新鲜和培养的牛角膜内皮的细胞内 pH 调节。

• 发表时间: 1992
• 期刊: Investigative ophthalmology & visual science
• 影响因子: 4.4
• 作者: Bonanno,JA;Giasson,C
• 通讯作者: Giasson,C

Enhancement of HCO(3)(-) permeability across the apical membrane of bovine corneal endothelium by multiple signaling pathways.

通过多种信号通路增强 HCO(3)(-) 穿过牛角膜内皮顶膜的通透性。

• 发表时间: 2002
• 期刊: Investigative ophthalmology & visual science
• 影响因子: 4.4
• 作者: Zhang,Yan;Xie,Qiang;Sun,XingCai;Bonanno,JosephA
• 通讯作者: Bonanno,JosephA

Role of carbonic anhydrase IV in corneal endothelial HCO3- transport.

碳酸酐酶 IV 在角膜内皮 HCO3- 转运中的作用。

• DOI: 10.1167/iovs.07-1188
• 发表时间: 2008
• 期刊: Investigative ophthalmology & visual science
• 影响因子: 4.4
• 作者: Sun,XingCai;Li,Jinhua;Cui,Miao;Bonanno,JosephA
• 通讯作者: Bonanno,JosephA

Reevaluation of Cl / HCO 3 Exchange in Cultured Bovine Corneal Endothelial Cells

培养牛角膜内皮细胞中 Cl / HCO 3 交换的重新评估

• 发表时间: 2005
• 作者: J. Bonanno;G. Yi;Xiaodong Rang;S. P. Srinivas
• 通讯作者: S. P. Srinivas