Inflammasomes Mediate Inflammation in Bladder Outlet Obstruction

 描述(申请人提供)：膀胱出口梗阻(BOO)是人们随着年龄增长而常见的疾病，如良性前列腺增生症。BOO导致下尿路症状(LUT)，通常是进行性的，随着时间的推移可能导致尿失禁甚至肾功能衰竭。目前的治疗方法并不总是有效地防止这种进展，数百万人患有令人烦恼的症状，这些症状已被证明显著降低了生活质量。这项研究显示了我们对BOO的理解和潜在治疗的范式转变，重点放在了继发于尿流阻力增加引起的压力升高引起的炎症上。这项工作源于2002年发现的超分子结构，即所谓的炎症体，它是由NOD样受体对致病刺激做出反应而形成的，也是在无菌炎症的背景下形成的，例如在BOO期间发现的。具体地说，NLRP3被认为是无菌炎症的介质。炎症小体通过导致IL-1？和IL-18这两种中枢促炎细胞因子的成熟和释放而引发炎症。虽然炎症小体在其他器官系统和疾病状态中的作用已经被阐明，但它们在尿路中的功能直到最近才被研究。我们的研究小组首次将NLRP3定位于尿路上皮细胞，并将其描述为在环磷酰胺诱导的膀胱炎的发生过程中发挥核心作用，环磷酰胺诱导的膀胱炎是一种广泛研究的膀胱无菌炎症模型。在这个方案中，我们验证了TE假设，即BOO引起的压力升高激活了尿路中的NLRP3，并引发了膀胱炎。反过来，炎症反应导致下尿路综合征和纤维化，这与这种病理状态下的临床恶化相对应。我们还将确定I NLRP3的激活导致尿路上皮的表型变化，从而引发进一步的膀胱功能障碍。我们的初步数据有力地表明，抑制BOO大鼠的NLRP3大大减少了通常被认为是梗阻的对膀胱的有害影响。在目标1中，我们将演示尿路上皮细胞系(MYP3)中的NLRP3在压力下被激活，并探讨其发生的机制。目的2是一项在大鼠身上进行的体内研究，将使我们能够确定NLRP3在BOO期间炎症、尿路上皮信号改变、排尿功能障碍、纤维化和肾损害的发展中所起的作用。在AIM 2中使用FDA批准的药物格列本脲作为NLRP3抑制剂，使该项目具有很强的翻译潜力，因为这可能会立即为患有BOO的患者带来好处。

 DESCRIPTION (provided by applicant): Bladder outlet obstruction (BOO) is common in people as they age due to conditions such as benign prostatic hyperplasia. BOO causes lower urinary tract symptoms (LUTS) that are usually progressive and can lead to urinary incontinence and even renal failure over time. Current therapies are not always effective at preventing this progression and millions of people suffer from bothersome symptoms that have been shown to significantly decrease quality of life. This study presents a paradigm shift in our understanding and potential treatment of BOO by focusing on the inflammation evoked by elevated pressures secondary to increased resistance to urinary outflow. This work springs from the discovery in 2002 of supra-molecular structures, known as inflammasomes, which are formed from Nod-like receptors in response to pathogenic stimuli and also in the setting of sterile inflammation such as is found during BOO. Specifically, NLRP3 is thought to be the mediator of sterile inflammation. Inflammasomes trigger inflammation by causing the maturation and release of IL-1ß and IL-18, two central pro- inflammatory cytokines. While the role of inflammasomes has been elucidated in other organ systems and disease states, their function in the urinary tract has only recently been investigated. Our group was the first to localize them to the urothelium and characterize NLRP3 as playing a central role in the setting of cyclophosphamide-induced cystitis, a well-studied model of sterile inflammation in the bladder. In this proposal, we test te hypothesis that elevated pressure caused by BOO activates NLRP3 in the urothelia and initiates bladder inflammation. In turn, the inflammatory response leads to LUTS and fibrosis which corresponds to the clinical deterioration seen in this pathological state. We will also determine i NLRP3 activation causes phenotypic changes in the urothelium which provoke further bladder dysfunction. Our preliminary data strongly suggests that inhibition of NLRP3 in BOO rats considerably diminishes the deleterious effects on the bladder that are normally seen with obstruction. In Aim 1 we will demonstrate that NLRP3 in a urothelial cell line (MYP3) is activated in response to pressure and we will probe the mechanism by which this occurs. Aim 2 is an in vivo study in rats that will allow us to define the role that NLRP3 plays in the development of inflammation, altered urothelial signaling, voiding dysfunction, fibrosis and renal impairment during BOO. Using an FDA-approved medication, glyburide, as the NLRP3 inhibitor in Aim 2 gives this project strong translational potential as this could provide immediate benefit to patients suffering from BOO.