Mitochondrial-Targeted Antioxidant-Encapsulating Nanoparticles as a Promising Therapeutic Strategy in Regulating Outflow Resistance

神经退行性疾病，包括青光眼，极大地改变了受影响退伍军人的生活质量。 青光眼仍然是不可逆转失明的主要原因。目前影响着6000多万人，这 隐匿性视神经病变的特征是RGC神经元逐渐丧失，预计将影响近 到2020年，人口将达到8000万。原发性开角型青光眼(POAG)的患病率 常见的青光眼形式，约占1.86%，或近200万人，年龄在45岁及以上 美国。尽管对DVA来说是一个非常重要的社会经济负担，但美国的治疗 患有POAG的退伍军人仍然是有限的和姑息的。目前的治疗方案仅限于非特异性治疗 旨在降低眼压的干预措施，眼压是POAG的一个鲜为人知的标志。对许多人来说 然而，青光眼退伍军人对眼压的药物和手术治疗仍处于临床阶段。 屈光的。针对高眼压原因制定有针对性的治疗策略至关重要 用于青光眼退伍军人的高级管理。 在健康的眼睛中，眼压通过平衡的房水产生和流出(AH)来维持。 小梁网/小梁旁组织(TM/JCT)对AH流出的阻力增加是一种 POAG患者眼压异常升高的主要原因。升高的分子机制 眼压仍然难以捉摸，但最可能涉及转化生长因子-β-2的异常表达和信号 (转化生长因子-β2)。大量研究表明，转化生长因子-β2是一种促进TM细胞生长的多功能细胞因子 收缩能力和细胞外基质(ECM)的合成和沉积在TM内显著增加 在POAG患者的AH中升高。虽然转化生长因子-β-2的细胞来源尚不清楚，但我们报告了 人TM细胞结构性地表达和分泌活性的转化生长因子-β2，突出TM是一个可行的靶点 而选择性转化生长因子-β-2下游信号通路的发展 抑制剂仍然是密集研究的重点，有针对性地干扰结构性转化生长因子-β2的表达 从TM释放代表了一种未被充分利用的治疗策略，用于POAG的眼压管理。 许多研究也报道了POAG患者AH中氧化应激标志物水平的升高，以及 TM中抗氧化防御的表达发生了变化。TM线粒体(MT)选择性氧化损伤 TM细胞功能障碍。转化生长因子-β诱导基因所需的MT产生的活性氧 表情。在这里，我们提出了未发表的发现，证明了mt靶向抗氧化剂显著地减弱了 转化生长因子-β-2在体外培养的人TM细胞中的表达和释放总体而言，mt生成的倒数第二个角色 转化生长因子-β-2介导的ROS减少了POAG的流出功能，升高的眼压开始出现。 假设：靶向干扰TM/JCT中结构性转化生长因子-β2的表达或信号转导 线粒体靶向抗氧化剂包裹的纳米颗粒将增加流出能力，降低眼压。这个 这项研究的假设将通过以下三个具体目标进行验证，使用体外和体内的组合 体外已建立的实验方法：目标1将在体外确定是否给人或猪灌流 线粒体靶向抗氧化剂包裹的纳米颗粒将保护眼前节免受 实验引起的流出设备的减少。目标2将确定，在体外，是给人类灌流还是 线粒体靶向抗氧化剂包裹纳米颗粒的猪眼前节将改变TM组织 完整性、内源性转化生长因子-β-2表达或转化生长因子-β-2介导的细胞外基质成分改变。目标3将阐明 线粒体靶向抗氧化剂纳米粒改变转化生长因子-β-2的机制(S) 转化生长因子-β-2的表达或介导细胞外基质成分的改变。 成功完成拟议的研究将是朝着发展这一目标迈出的关键的第一步 管理患有POAG的退伍军人的技术。

Neurodegenerative diseases, including glaucoma, substantially alter quality of life of the affected Veteran. Glaucoma remains a leading cause of irreversible blindness. Currently affecting over 60 million individuals, this insidious optic neuropathy is characterized by a gradual loss of RGC neurons and is projected to impact nearly 80 million people by the year 2020. The prevalence of primary open angle glaucoma (POAG), the most common form of glaucoma, is approximately 1.86%, or nearly 2 million individuals, 45 years of age and older in the US. Despite being an extraordinarily significant socioeconomic burden to the DVA, the treatment of US Veterans with POAG remains limited and palliative. Current treatment options are restricted to non-specific interventions aimed at lowering intraocular pressure (IOP), a poorly-understood hallmark of POAG. For many glaucomatous Veterans, however, pharmacological and surgical management of IOP remains clinically refractive. The development of targeted therapeutic strategies directed at the cause of elevated IOP is critical for the advanced management of glaucomatous Veterans. In healthy eyes, IOP is maintained through balanced production and outflow of aqueous humor (AH). Increased resistance to AH outflow through the trabecular meshwork/juxtacanalicular tissue (TM/JCT) is a major contributor of aberrant elevation of IOP in POAG. The molecular mechanisms responsible for elevated IOP remain elusive, but most likely involve aberrant expression and signaling of transforming growth factor-β2 (TGF-β2). Numerous studies demonstrate that TGF-β2, a multifunctional cytokine that promotes TM cell contractility and increased extracellular matrix (ECM) synthesis and deposition within the TM, is markedly elevated in the AH of patients with POAG. While the cellular origin of TGF-β2 is unclear, we reported that human TM cells constitutively express and secrete active TGF-β2, highlighting the TM as a viable targetable source of active TGF-β2. Whereas the development of selective TGF-β2 downstream signaling pathway inhibitors continues to be the focus of intense investigations, targeted disruption of constitutive TGF-β2 expression and release from the TM represents an underexploited therapeutic strategy for the management of IOP in POAG. Numerous studies also report elevated levels of oxidative stress markers in AH of POAG patients, along with altered expression of antioxidant defenses in the TM. Selective oxidative damage to TM mitochondria (Mt) elicits TM cell dysfunction. Mt-generated reactive oxygen species (ROS) are required for TGF-β induced gene expression. Here, we present unpublished findings demonstrating Mt-targeted antioxidants significantly attenuate expression and release of TGF-β2 from cultured human TM cells. Collectively, a penultimate role of Mt-generated ROS in TGF-β2 mediated decreases in outflow facility and increased IOP in POAG begins to emerge. Hypothesis: Targeted disruption of constitutive TGF-β2 expression or signaling within the TM/JCT with mitochondrial-targeted antioxidant-encapsulating nanoparticles will increase outflow facility and lower IOP. The hypothesis of this study will be tested with the following three Specific Aims using a combination of ex vivo and in vitro established experimental approaches: Aim 1 will determine, ex vivo, whether perfusing human or porcine anterior segments with mitochondrial-targeted antioxidant-encapsulating nanoparticles will protect against experimentally induced decreases in outflow facility. Aim 2 will determine, ex vivo, whether perfusing human or porcine anterior segments with mitochondrial-targeted antioxidant-encapsulating nanoparticles will alter TM tissue integrity, endogenous TGF-β2 expression, or TGF-β2 mediated changes in ECM composition. Aim 3 will elucidate the mechanism(s) by which mitochondrial-targeted antioxidant-encapsulating nanoparticles alter TGF-β2 expression or TGF-β2 mediated changes in ECM composition in cultured human TM cells. Successful completion of the proposed study will serve as a critical first step toward developing this technology for the management of Veterans with POAG.