The microtubule cytoskeleton as a novel target for cavernous nerve regeneration after prostatectomy

微管细胞骨架作为前列腺切除术后海绵体神经再生的新靶点

• 批准号: 9240100
• 负责人: KELVIN P DAVIES
• 金额: $ 57.84万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE, INC
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2021-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9240100
• 关键词: Aftercare; Animal Model; Animals; Blood Pressure; Clinical; Control Animal; Cutaneous; Cytoskeleton; Encapsulated; Erectile dysfunction; Formulation; Foundations; Gene Expression Profiling; Goals; Growth Cones; Histopathology; In Vitro; Injury; Investigation; Investigational New Drug Application; Knowledge; Lead; Lipids; Malignant neoplasm of prostate; Measures; Mediating; Microtubules; Modeling; Natural regeneration; Nerve; Nerve Regeneration; Neurons; Operative Surgical Procedures; Outcome; Pathology; Patients; Peripheral Nervous System; Procedures; Prostatectomy; Radical Prostatectomy; Rattus; Recovery; Recovery of Function; Research; Research Personnel; Safety; Site; Small Interfering RNA; Testing; Therapeutic; Time; Tissues; Topical application; Toxic effect; Treatment Protocols; Visual; Work; axon growth; axon regeneration; clinical translation; comparative; experimental study; high risk; improved; insight; men; mouse model; nanoparticle; nerve injury; neuronal growth; new technology; novel; novel strategies; prevent; protein phosphatase inhibitor-2; regenerative; repaired

Abstract Radical prostatectomy (RP) is a commonly used treatment option for localized prostate cancer. Unfortunately, the procedure carries a high risk of erectile dysfunction (ED) which is highly detrimental to the post-surgical well-being of men. The main pathophysiological mechanism behind ED is damage to the cavernous nerves (CN); mechanisms that regenerate or repair CN injury following RP could alleviate or treat ED in these patients. The studies outlined in this proposal will pursue a novel approach to CN repair by harnessing the nerve regenerative powers of Fidgetin-like 2 (FL2), a newly discovered microtubule regulator. In vitro studies indicate that the depletion of FL2 strongly enhances axonal growth in primary cultures of rat peripheral nervous system neurons. Recent work by the investigators involved in this proposal have shown that targeted depletion of FL2 via topical application of FL2-siRNA encapsulated in nanoparticles (FL2-siRNA-np) promotes the closure and regeneration of cutaneous wounds in mouse models and improved erectile function outcomes in a rat model of RP when applied at the time of CN injury. Remarkably, in a CN transection model of RP, at two weeks post treatment with FL2-siRNA there is both improved erectile function outcomes and visible nerve regrowth. These observations lead us to the hypothesis to be tested in this proposal that “following CN injury, depletion of FL2 activates mechanisms that promote cavernous nerve regeneration, leading to accelerated recovery of erectile function”. This hypothesis will be tested in two specific aims. In the first Specific Aim we will substantiate our preliminary results that depletion of FL2 improves recovery of erectile function following CN injury used as an animal model of RP. We will optimize formulation and treatment regimens for ED. FL2-siRNA will be applied at the site of CN injury both at the time, and one week following injury and recovery of erectile function determined by measuring the intracorporal pressure/blood pressure ratio (ICP/BP) developed after CN stimulation, at various time points after treatment. Following cavernosometry, we will perform pathology studies to provide evidence of CN regeneration and safety of the different formulations. In the second Specific Aim we will conduct experiments to elucidate the mechanism by which the depletion of FL2 promotes functional recovery after CN injury. We will determine the effects of FL2-siRNA on axon growth and regeneration in vitro. Using tissues of controls and FL2-siRNA treated animals we will perform extensive comparative histopathology and gene expression analyses on corporal tissue and from the site of injury of treated versus control rats at various time-points after CN injury. Overall, upon completion of this proposal we will have established the potential of FL2 as a novel target in repairing CN damage following RP, determined treatment regimens, formulation and safety considerations to optimize potential clinical translation and have gained insight into the mechanism of FL2 mediated CN repair.

摘要 根治性前列腺切除术（RP）是局限性前列腺癌的常用治疗选择。 不幸的是，该过程具有勃起功能障碍（艾德）的高风险，这对患者的健康非常不利。 男性术后的幸福感艾德的主要病理生理机制是海绵状血管的损伤 RP后再生或修复CN损伤的机制可以减轻或治疗这些神经（CN）中的艾德。 患者本提案中概述的研究将通过利用神经来寻求CN修复的新方法 Fidgetin-like 2（FL 2）的再生能力，一种新发现的微管调节剂。体外研究表明 FL 2的缺失强烈增强大鼠外周神经系统原代培养物中轴突的生长 神经元参与这项提议的研究人员最近的工作表明，靶向消耗FL 2 通过局部应用封装在纳米颗粒中的FL 2-siRNA（FL 2-siRNA-np）促进闭合， 小鼠模型中皮肤伤口的再生和大鼠模型中勃起功能结果的改善 在CN损伤时应用RP。值得注意的是，在RP的CN横断模型中，在术后两周， 用FL 2-siRNA治疗，勃起功能结果得到改善，神经再生可见。这些 观察结果使我们提出了在该提议中待检验的假设，即“CN损伤后， 激活机制，促进海绵体神经再生，导致加速恢复 勃起功能”。这一假设将在两个具体目标中得到检验。 在第一个具体目标中，我们将证实我们的初步结果，即FL 2的消耗改善了 CN损伤后勃起功能的恢复用作RP的动物模型。我们将优化配方 FL 2-siRNA将在CN损伤的时间和一周内应用于CN损伤部位。 通过测量颅内压/血压确定的勃起功能损伤和恢复后 在CN刺激后，在治疗后的不同时间点产生压力比（ICP/BP）。以下 我们将进行病理学研究，以提供CN再生和安全性的证据。 不同的配方。 在第二个具体目标，我们将进行实验，以阐明机制， FL 2的缺失促进CN损伤后的功能恢复。我们将确定FL 2-siRNA对细胞凋亡的影响。 体外轴突生长和再生。使用对照和FL 2-siRNA处理的动物的组织，我们将进行 广泛的比较组织病理学和基因表达分析的身体组织和从网站的 在CN损伤后的不同时间点，治疗组与对照组大鼠的损伤。 总的来说，在完成本提案后，我们将确定FL 2作为新靶点的潜力 在RP后修复CN损伤中，确定了治疗方案、制剂和安全性考虑因素， 优化潜在的临床翻译，并深入了解FL 2介导的CN修复机制。