Cystitis-Induced Plasticity of Micturition Reflexes

描述（由申请方提供）：膀胱疼痛综合征（PBS）/间质性膀胱炎（IC）是一种慢性膀胱综合征，其特征为尿频、尿急、耻骨上、盆腔疼痛和膀胱镜检查结果。本研究建议的假设是，伴随PBS/IC的排尿频率增加和感觉改变是由于排尿反射的初级传入肢的改变，部分是由于脊髓中神经元间机制的改变。膀胱炎引起的尿频也可能是由于排尿反射传出支的改变。这些变化的组合通过改变神经元间水平和骨盆神经节的突触传递促进了到膀胱的脊髓反射通路。神经生长因子（NGF）和神经生长因子/受体酪氨酸激酶（TrkA）的相互作用，炎症引起的膀胱功能的变化，神经化学可塑性下尿路（LUT）通路和中枢组织的LUT反射的贡献已被定义。所提出的目标提供了机制的洞察炎症引起的排尿反射的神经控制的变化，使用膀胱炎症的大鼠模型，一种新的，慢性过度表达的NGF小鼠系（UPII-NGFv 2）和多学科的实验方法。目标1：为了模拟慢性膀胱炎症和PBS/IC的环境，将使用在尿路上皮中具有NGF的慢性过表达（UPII-NGFv 2）的小鼠来确定NGF在介导膀胱反射的功能、神经化学和组织可塑性中的作用，使用有意识膀胱测压、免疫组织化学和细胞内记录技术。神经可塑性是否继发于排尿反射的神经化学表型的变化将被确定。目的2：p75 NTR与Trk受体相互作用，调节TrkA受体与其同源配体NGF的亲和力。将确定对照、CYP处理的啮齿动物、UPII-NGFv 2和回交野生型小鼠中LUT途径中Trk相对于p75 NTR介导的信号传导的参与。这些研究将使用药理学工具来阻断NGF/TrkA与NGF/p75信号传导。目的3：神经营养素诱导的信号的生物学作用是未知的，特别是在LUT。将测定CYP诱导的膀胱炎后大鼠和UPII-NGFv 2小鼠中腰骶脊髓、DRG和膀胱中ERK 1/2、ERK 5和Akt的时间激活。将测定ERK或PI 3 K抑制剂给药后脊髓排尿反射的神经化学性质和组织。这些研究可能为未来PBS/IC的潜在靶点和治疗干预提供见解。 公共卫生相关性 疼痛性膀胱综合征（PBS）/间质性膀胱炎（IC）是一种慢性膀胱综合征，其特征为尿频、尿急、耻骨上、盆腔疼痛和膀胱镜检查结果。炎症诱导的生长因子（例如神经生长因子，NGF）在PBS/IC女性膀胱或尿液中的表达以及随后与中枢和外周神经系统的相互作用可能导致这些症状。这些研究将确定NGF与膜结合受体的相互作用和细胞信号事件的激活如何导致膀胱功能障碍和感觉处理的变化。这些研究将有助于了解慢性膀胱炎症中炎症诱导的变化，并可能为未来PBS/IC的潜在靶点和治疗干预提供见解。

DESCRIPTION (provided by applicant): Painful Bladder Syndrome (PBS)/Interstitial Cystitis (IC) is a chronic symptom-complex characterized by urinary frequency, urgency, suprapubic, pelvic pain and cystoscopic findings. The hypothesis for this research proposal is that increases in voiding frequency and altered sensation that accompany PBS/IC are due to an alteration in the primary afferent limb of the micturition reflex and, in part, to an alteration in interneuronal mechanisms in the spinal cord. Increased urinary frequency with cystitis may also be due to an alteration in the efferent limb of the micturition reflex. The combination of these changes facilitates a spinal reflex pathway to the urinary bladder by altering synaptic transmission at the interneuronal level and to the pelvic ganglia. The contribution of nerve growth factor (NGF) and NGF/receptor tyrosine kinase (TrkA) interactions to inflammatory-induced changes in urinary bladder function, neurochemical plasticity in lower urinary tract (LUT) pathways and central organization of LUT reflexes has been defined. The proposed aims provide mechanistic insight into inflammation-induced changes in neural control of micturition reflexes using the CYP rat model of urinary bladder inflammation, a novel, chronic overexpressing NGF mouse line (UPII-NGFv2) and a multidisciplinary experimental approach. Aim 1: To mimic the environment of chronic bladder inflammation and PBS/IC, mice with chronic overexpression of NGF in the urothelium (UPII-NGFv2) will be used to determine the role that NGF plays in mediating functional, neurochemical and organizational plasticity of bladder reflexes using conscious cystometry, immunohistochemistry and intracellular recording techniques. Whether neural plasticity is secondary to changes in neurochemical phenotype of the micturition reflex will be determined. Aim 2: p75NTR and Trk receptors interact to regulate the affinity of TrkA receptor for its cognate ligand, NGF. The involvement of Trk versus p75NTR mediated signaling in LUT pathways in control, CYP-treated rodents, UPII-NGFv2 and backcrossed wildtype mice will be determined. These studies will use pharmacological tools to block NGF/TrkA versus NGF/p75 signaling. Aim 3: The biological roles of neurotrophin-induced signals are unknown especially in the LUT. The temporal activation of ERK1/2, ERK5 and Akt in lumbosacral spinal cord, DRG and urinary bladder after CYP-induced cystitis in rats and in UPII-NGFv2 mice will be determined. The neurochemical properties and the organization of spinal micturition reflexes after administration of ERK or PI3K inhibitors will be determined. These studies may provide insights into potential targets and therapeutic interventions for PBS/IC in the future. PUBLIC HEALTH RELEVANCE Painful Bladder Syndrome (PBS)/Interstitial Cystitis (IC) is a chronic symptom-complex characterized by urinary frequency, urgency, suprapubic, pelvic pain and cystoscopic findings. Inflammation-induced expression of growth factors (e.g. nerve growth factor, NGF) in the urinary bladder or urine of women with PBS/IC and subsequent interactions with the central and peripheral nervous system may contribute to these symptoms. These studies will determine how NGF interactions with membrane bound receptors and activation of cellular signaling events could contribute to urinary bladder dysfunction and changes in sensory processing. These studies will contribute to the understanding of inflammation-induced changes in chronic bladder inflammation and may provide insights into potential targets and therapeutic interventions for PBS/IC in the future.