EFFECT OF DENERVATION ON THE FUNCTION OF THE AIRWAYS

神经系统调节气道对炎症刺激的反应。这里描述的研究继续进行中的P物质和其他前速激肽原（PPT）-A基因编码的速激肽在这种调制中的作用的研究。拟议的工作适用于遗传改变的鼠系统：1。定义气道肽能感觉-运动网络的拓扑组织和层次连接，2.鉴定响应于炎症刺激而释放的PPT-A速激肽的细胞来源，并阐明三种候选细胞类型（感觉神经元、内在神经节或造血细胞）对随后的损伤的贡献，以及3.确定PPT-A基因的过度表达本身是否会产生炎性损伤或需要单独的炎性刺激。目的1将通过检查置于PPT-A 5'调控区的转录控制下的荧光蛋白（ECFP）的表达，结合使用伪狂犬病病毒作为逆行跨突触标记的追踪研究来实现。目标2将通过辣椒素选择性化学消融C-纤维和野生型小鼠和PPT-A和NK-1受体基因靶向破坏纯合子小鼠骨髓重建实验的组合来实现。这些操作的效果，然后将在完整的，发炎（免疫复合物，仙台病毒，和牵拉诱导），和去神经支配的气道（选择性C纤维消融和异位气管移植）进行比较。目的3将通过分析PPT-A基因的转基因操作的影响来实现，所述转基因操作导致气道上皮细胞中PPT-A的异位组成型过表达或完整和发炎气道中PPT-A的同位素诱导型过表达（见上文）。这些目标的完成将提高我们对气道神经源性损伤的理解，并可能有助于制定治疗策略，以最大限度地减少速激肽扩增的免疫介导的炎症的肺和气道的疾病过程中，如闭塞性细支气管炎肺移植后或高氧/机械通气后牵拉损伤。

The nervous system modulates the responses of the airways to inflammatory stimuli. The studies described here continue ongoing research into the role of substance P and other preprotachykinin (PPT)-A gene-encoded tachykinins in this modulation. The proposed work applies genetically altered murine systems to: 1. define the topographical organization and hierarchical connectivity of the airway's peptidergic sensory-motor network, 2. identify the cellular origin of the PPT-A tachykinins released in response to inflammatory stimuli and elucidate the contribution of three candidate cell types (sensory neurons, intrinsic ganglia, or hemopoietic cells) to the ensuing injury, and 3. establish whether over-expression of the PPT-A gene can in itself produce an inflammatory injury or requires a separate inflammatory stimulus. Aim 1 will be accomplished by examining the expression of a fluorescent protein (ECFP) placed under the transcriptional control of the PPT-A 5' regulatory region in conjunction with tracking studies using pseudorabies virus as a retrograde trans-synaptic marker. Aim 2 will be approached by a combination of selective chemical ablation of C-fibers by capsaicin and bone marrow reconstitution experiments in wild type mice and mice homozygous for targeted disruptions of the PPT-A and NK-1 receptor genes. The effects of these manipulations will then be compared in intact, inflamed (immune complex, Sendai virus, and stretch-induced), and denervated airways (selective C-fiber ablation and heterotopic tracheal transplantation). Aim 3 will be achieved by analyzing the effects of transgenic manipulations of the PPT-A gene resulting either in ectopic constitutive overexpression of PPT-A in airway epithelial cells or in isotopic inducible over-expression of PPT-A in intact and inflamed airways (see above). Completion of these aims will improve our understanding of airway neurogenic injury and may help to develop therapeutic strategies to minimize tachykinin amplification of immune-mediated inflammation of the lungs and airways in disease processes such as bronchiolitis obliterans after lung transplantation or hyperoxic/stretch injury after mechanical ventilation.