TNF-alpha activation of Rho-kinase in cavernous nerve injury

描述(申请人提供)：前列腺癌手术治疗的主要后遗症是术后勃起功能障碍(ED)。神经病学领域的进展主要集中在制定和实施策略，以保留阴茎勃起的神经发生基础和海绵体神经(CN)的功能完整性，从而最大化术后勃起功能的结果。在自主神经核损伤后，有一个微环境的变化，使轴突易于退化，部分神经纤维将在神经营养刺激下再生。最近才对CN损伤后促进神经病变的细胞和分子机制进行了研究，有力地支持了细胞因子诱导和导致轴突变性的炎症机制的参与。现在，主要的挑战是确定导致损伤后甚至在糖尿病和衰老等疾病状态下导致CN变性的关键分子事件和信号转导网络。这项工作具有特别重要的意义，因为识别导致CN功能障碍的关键分子开关可能会为这一重要的性医学问题带来新的治疗范例。在这一应用中，我们建议通过研究细胞因子(肿瘤坏死因子-？)炎症(巨噬细胞)环境是CN损伤后主要骨盆神经节(MPG)RhoA/Rho-Kinase(ROCK)信号的关键上游激活物。MPG中ROCK信号的激活促进了神经元胞体的凋亡，从而减少了通过CN到阴茎末端器官的突触传递。通过结合体外肌图仪实验、神经发生的体外解释MPG测量和体内CN损伤动物模型的勃起生理血流动力学变化，我们准备扩展我们在MPG中RhoA/ROCK信号的工作，该工作由之前的NIDDK K08奖项申请资助。由于细胞因子、巨噬细胞趋化作用和ROCK信号转导容易被药物抑制剂操纵，这项工作不仅将加深我们对CN损伤后病理生理学的基本认识，也将为神经源性ED提供潜在的新的治疗选择。

DESCRIPTION (provided by applicant): Major sequela from the surgical management of prostate cancer is post-operative erectile dysfunction (ED). Advances in the field of neurourology have focused on the development and implementation of strategies for preserving the neurogenic basis of penile erection and functional integrity of the cavernous nerves (CN) following RP and thus maximizing postoperative erectile function outcomes. Following injury to the autonomic CN, there is a microenvironment change that predisposes the axons to degeneration with a proportion of nerve fibers which will regenerate with neurotrophic stimulus. The cellular and molecular mechanisms promoting neuropathy following CN injury is only recently been investigated with strong support for the involvement of cytokine induction and inflammatory mechanisms which lead to axonal degeneration. Now, the major challenge is identifying the key molecular events and signal transduction networks which lead to CN degeneration after injury or even in disease states such as diabetes mellitus and aging. This work is of particular importance because identification of key molecular switches that lead to CN dysfunction may lead to new treatment paradigms for this important problem in sexual medicine. In this application, we propose to address these issues by studying how the cytokine (TNF-?) and inflammatory (macrophage) milieu serve as a critical upstream activator of RhoA/Rho-kinase (ROCK) signaling in the major pelvic ganglion (MPG) after CN injury. Activation of ROCK signaling in the MPG promotes neuronal cell body apoptosis and thus reduction of synaptic transmission through the CN to the end-organ penis. Using a combination of in vitro myograph experiments, ex vivo explanted MPG measurements of neuritogenesis, and in vivo erectile physiology hemodynamic changes in an animal model of CN injury, we are poised to extend our work on RhoA/ROCK signaling in the MPG which was funded by a previous NIDDK K08 award application. As cytokines, macrophage chemoattraction, and ROCK signaling is easily manipulated by pharmacologic inhibitors, this work will not only add to our basic understanding of CN pathophysiology after injury, but also provide potential new therapeutic options for neurogenic-ED.