Mechanisms of Neurogenic Bladder Dysfunction in EAE Mice

描述（由申请人提供）：神经性尿失禁（NUI）是神经性膀胱功能障碍（NBD）最令人烦恼的表现。NBD是由神经系统问题如多发性硬化症（MS）引起的膀胱功能障碍的统称。多发性硬化症是影响20至45岁女性的最常见的致残性神经系统疾病。MS是一种进行性退行性自身免疫性疾病，由于整个神经系统的脱髓鞘病变而损害神经元功能，影响膀胱及其出口的功能。女性多发性硬化症的发病率是男性的两倍，超过80%的女性多发性硬化症患者存在NUI。在患病时间超过10年的患者中，NUI患病率上升至96%以上。虽然ms相关的NBD和NUI的潜在病理生理机制尚不清楚，但有研究表明，NBD的发生是脱髓鞘破坏连接中枢神经系统控制与膀胱脊髓和外周神经通路和下尿路功能的神经通路，从而破坏膀胱功能的储存期和排尿期。因此，尿失禁可以表现为膀胱储存失败（急迫性尿失禁）或排空（溢流性尿失禁）的结果。此外，多发性硬化症的波动性和不可预测的缓解和复发模式使患有多发性硬化症的女性膀胱功能恶化，这导致了与多发性硬化症相关的发病率和死亡率的沉重负担。我们最近创建了一个NBD小鼠模型，模拟了人类多发性硬化症的临床过程，包括储存功能障碍、排尿问题和逼尿肌括约肌协作障碍（DSD）。实验性自身免疫性脑脊髓炎（EAE）小鼠为我们提供了独特的机会来研究与NBD和NUI相关的关键未解研究问题。我们假设EAE临床评分为0-4分的雌性SWXJ小鼠表现出相应的膀胱存储或排尿功能障碍，可预测NBD的类型。进一步，我们假设DSD的膀胱出口梗阻性小鼠由于膀胱反射性而出现溢流性尿失禁，而非DSD的小鼠由于膀胱反射性亢进而出现膀胱过度活跃（OAB）和急迫性尿失禁。这些假设将通过三个具体目标进行检验。在目的1中，将通过同时进行的膀胱电图和肌电图来评估EAE中NBD的储存期和排尿期的时间特征。目的2将中枢神经系统组织病理学和神经功能缺陷与EAE小鼠NBD的储存和排空期联系起来。最后，目的3将检查整个体外神经源性膀胱的收缩反应。这种动物模型结合了同时评估膀胱和出口功能的创新方法，将使我们能够以一种全新的方式研究NUI的机制，为数百万患有NUI的女性发现预防和治疗干预措施打开大门。

DESCRIPTION (provided by applicant): Neurogenic Urinary Incontinence (NUI) is the most bothersome manifestation of Neurogenic Bladder Dysfunction (NBD). NBD refers collectively to bladder dysfunctions that are caused by neurological problems such as multiple sclerosis (MS). MS is the most common disabling neurological disorder affecting women between 20 and 45 years old. MS is a progressive degenerative autoimmune disease that impairs neuronal functions due to demyelinating lesions throughout the nervous system, affecting the function of the bladder and its outlet. MS is twice as frequent in women as in men, and more than 80% of women with MS present with NUI. The prevalence of NUI rises to more than 96% in those with the disease for longer than 10 years. While the underlying pathophysiology of MS-associated NBD and NUI remains poorly understood, it is suggested that NBD occurs as a result of demyelination interrupting the neural pathways connecting the central nervous system control to the spinal and peripheral neuronal pathways of the bladder and lower urinary tract function, thus disrupting both the storage and voiding phase of bladder function. Thus, NUI can present as a result of failure of bladder storage (urge incontinence) or emptying (overflow incontinence). Further, the fluctuating nature of MS with unpredictable patterns of remissions and relapses exposes women with MS to deteriorating bladder function that contributes to the heavy burden of morbidity and mortality associated with MS. We have recently created a mouse model of NBD that mimics the clinical course of MS in humans, including storage dysfunction, voiding problems and detrusor sphincter dyssynergia (DSD). The mouse with Experimental Autoimmune Encephalomyelitis (EAE) has afforded us with the unique opportunity to investigate the key unanswered research questions related to NBD and NUI. We hypothesize that female SWXJ mice with EAE in clinical scores 0-4 demonstrate a corresponding storage or voiding bladder dysfunction predictive of the type of NBD. Further, we hypothesize that mice with bladder outlet obstructive pattern from DSD have overflow incontinence due to areflexia bladder, and mice without DSD have overactive bladder (OAB) and urge incontinence due to hyperreflexia bladder. The hypotheses will be tested with three specific aims. In aim 1 the temporal characteristics of storage and voiding phases of NBD in EAE will be assessed by simultaneous cystometrogram and electromyogram. Aim 2 will correlate CNS histopathology and neurologic deficit with defined storage and voiding phases of NBD in EAE mice. Finally, aim 3 will examine contractile responses of the whole neurogenic bladder in vitro. This animal model combined with innovative methods of simultaneous assessment of bladder and outlet function, will allow us to investigate the mechanisms of NUI in a whole new way, opening the gates for discovery of preventive and therapeutic interventions for millions of women suffering from NUI. PUBLIC HEALTH RELEVANCE: Neurogenic Urinary Incontinence (NUI) is the most bothersome manifestation of Neurogenic Bladder Dysfunction (NBD). NBD refers collectively to bladder dysfunctions that are caused by neurological problems such as multiple sclerosis (MS). The bladder has two primary functions urine storage and emptying. In NUI either of these functions might be impaired. Using a mouse model of MS, we will investigate the specific mechanism of NUI leading to rational design of preventive and therapeutic interventions.