Nerve Evoked Signaling in Urinary Bladder Smooth Muscle

膀胱平滑肌中的神经诱发信号

基本信息

批准号：
7092012
负责人：
MARK T NELSON
金额：
$ 34.88万
依托单位：
UNIVERSITY OF VERMONT & ST AGRIC COLLEGE
依托单位国家：
美国
项目类别：
财政年份：
2004
资助国家：
美国
起止时间：
2004-07-15 至 2008-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7092012
关键词：
biological signal transduction calcium channel calcium flux cholinergic receptors confocal scanning microscopy endoplasmic reticulum gene expression genetically modified animals immunofluorescence technique laboratory mouse morphometry muscarinic receptor muscle contraction neural transmission protein kinase C purinergic receptor receptor coupling smooth muscle urinary bladder disorder urinary bladder epithelium urinary tract obstruction voltage gated channel

biological signal transduction calcium channel calcium flux cholinergic receptors confocal scanning microscopy endoplasmic reticulum gene expression genetically modified animals immunofluorescence technique laboratory mouse morphometry muscarinic receptor muscle contraction neural transmission protein kinase C purinergic receptor receptor coupling smooth muscle urinary bladder disorder urinary bladder epithelium urinary tract obstruction voltage gated channel

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项目摘要

DESCRIPTION (provided by applicant): A central function of urinary bladder smooth muscle (UBSM) is the translation of neural inputs into a normal micturition response, a function that is dramatically altered with outlet obstruction. This proposal focuses on how these neural inputs through cholinergic and purinergic pathways differentially impact calcium (Ca2+) signal patterning in UBSM, and on electrical and contractile responses under normal conditions and with partial outlet obstruction. Despite the importance of these pathways, major gaps remain in our knowledge o1 the underlying nerve-evoked excitation-contraction (E-C) coupling mechanisms and the changes that occur with obstruction. In a major advance, we have been able to measure, with high spatial and temporal resolution, nerve excitation, and local Ca2+ signals in intact whole urinary bladders and bladder strips. We have identified two distinct local calcium transients in UBSM: 1) nerve-evoked calcium transients, mediated through purinergic receptors, and 2) the local release of calcium from the sarcoplasmic reticulum (SR) through ryanodine receptors (RyRs). Aim 1 seeks to elucidate the novel mechanisms by which UBSM decodes cholinergic and purinergic stimulation into different calcium signals, which differentially depend on Ca2+ entry through voltage-dependent calcium channels (VDCC), inositol triphosphate receptors (IP3Rs) and RyRs in the SR. Aim 2 focuses on UBSM E-C coupling mechanisms in response to the unique calcium signals elicited by cholinergic and purinergic mechanisms. In Aim 3, we explore the interaction of VDCC and SR Ca2+ load in mediating cholinergic and purinergic excitation in normal and dysfunctional bladders. The hypothesis that SR dysfunction following outlet obstruction differentially affects cholinergic and purinergic stimulation by altered UBSM calcium signaling will be tested. Using state-of-the-art techniques, genetically altered mice, and our recently developed mouse model of partial bladder outlet obstruction, the proposed study will provide new insights into the differential impact of cholinergic and purinergic pathways on UBSM in normal and obstructed bladders. The novel findings of this study will be highly relevant to understanding fundamental mechanisms of nerve-evoked E-C coupling in UBSM, and identify key elements that underlie bladder dysfunction, and as such should be highly relevant to the understanding and treatment of bladder dysfunction.

描述（由申请人提供）：膀胱平滑肌（UBSM）的中心功能是将神经输入转换为正常的排尿反应，该功能随着出口阻塞而大大改变。该提案重点是这些神经输入如何通过胆碱能和嘌呤能途径差异影响瑞银（UBSM）中的钙（CA2+）信号模式，以及在正常条件下以及部分出口障碍物下的电和收缩反应。尽管这些途径很重要，但我们的知识仍然存在主要差距O1，基本的神经诱发的激发 - 收缩（E-C）耦合机制以及阻塞发生的变化。在一个重大的进步中，我们能够以高空间和时间分辨率，神经激发以及完整的整个尿膀胱和膀胱带中的局部CA2+信号进行测量。我们已经确定了UBSM中的两个不同的局部钙瞬变：1）通过嘌呤能受体介导的神经诱发的钙瞬变，以及2）局部钙从肌浆网（SR）通过ryanonodine受体（RYRS）释放。 AIM 1试图阐明UBSM将胆碱能和嘌呤能刺激解码为不同的钙信号的新型机制，这些钙信号通过电压依赖性钙通道（VDCC），肌醇三磷酸受体（IP3RS）和SR中的Ryrs差异依赖于Ca2+进入。 AIM 2重点介绍了UBSM E-C耦合机制，以响应胆碱能和嘌呤能机制引起的独特钙信号。在AIM 3中，我们探讨了VDCC和SR Ca2+负载在正常和功能失调的膀胱中介导胆碱能和嘌呤能激发中的相互作用。将测试通过改变的ubsm钙信号传导差异地影响SR功能障碍后的SR功能障碍会差异地影响胆碱能和嘌呤能刺激。拟议的研究使用最先进的技术，遗传改变的小鼠以及我们最近开发的小鼠部分部分膀胱出口阻塞的模型，将为胆碱能和嘌呤能途径对正常和阻塞膀胱的UBSM的差异影响提供新的见解。这项研究的新发现将与理解UBSM中神经诱发的E-C耦合的基本机制高度相关，并确定膀胱功能障碍的关键要素，因此应该与膀胱功能障碍的理解和治疗高度相关。