Morphological, molecularbiological and functional characterization of neuromuscular alteratoins in diverticular disease

憩室病是最常见的胃肠道疾病之一。尽管发病率很高，但DD的发病机制在很大程度上仍然是个谜。最近的证据表明，DD是由神经肌肉的变化，触发憩室的形成以及症状。在以前的资助期间，我们通过分析从憩室炎患者和肠神经细胞培养中获得的样本，能够表明DD（1）与肠神经细胞的损失有关（2）显示神经营养因子GDNF及其相应受体的表达缺陷（RET，GFRa 1/2），这反过来又可能解释神经细胞的损失;（3）特征在于多巴胺能和毒蕈碱神经递质系统的紊乱，这有助于解释伴随DD的肠运动模式的改变，（4）显示结构和功能性肌肉变化，进一步表明DD中潜在的神经病变和肌病。基于这些数据，目前的建议旨在解决以下几个方面：（1）评估憩室炎患者中最重要的抑制性神经递质系统（NO，VIP）的变化，以及其他神经营养因子（GDNF家族成员，内皮素，神经调节素）是否显示表达缺陷。由于神经营养因子显著影响突触可塑性，因此突触可塑性的标志物（突触泡蛋白、小突触泡蛋白、突触结合蛋白、SNAP 25）将指示憩室炎是否与突触病相关。(2)迄今为止在憩室炎患者中进行的一组实验也将在憩室病患者中进行。如果这一集体揭示了类似的结果（如神经节细胞减少症，神经递质紊乱，神经营养因子的缺陷，突触病），这些数据将支持的假设，潜在的神经肌肉改变最初参与DD的发病机制。(3)将在体外模型中进一步研究在人体病理学中检测到的神经肌肉变化的潜在病理机制。为了这个目的，除了肠神经细胞培养，我们已经建立了培养的肠平滑肌细胞的模型。这些体外模型将允许评估显示在DD中改变的神经营养因子对肠神经细胞的增殖、分化和突触可塑性以及对肠平滑肌细胞的结构和功能分化的影响。在实验中获得的数据可以修改传统的DD的发病概念，并确定肠道神经/肌病的病因因素DD，这可能会允许开发创新的概念，预防和（药物）治疗方法。

Diverticular disease (DD) represents one of the most common gastrointestinal diseases. Despite the high prevalence, the pathogenesis of DD, however, remains largely enigmatic. Recent evidences indicate that DD is caused by neuromuscular alterations which trigger formation of diverticula as well as symptoms. During previous funding periods, we were able to show by analyzing samples obtained from patients with diverticulitis and enteric nerve cell cultures that DD (1) is associated with a loss of enteric nerve cells (oligoneuronal hypoganglionosis); (2) displays expression deficits of the neurotrophic factor GDNF and its corresponding receptors (RET, GFRa1/2) which in turn might account for the nerve cell loss; (3) is characterized by disturbances of the serotonergic and muscarinic neurotransmitter systems which helps to explain the altered intestinal motility patterns accompanying DD, (4) displays structural and functional muscular changes further indicating an underlying neuropathy and myopathy in DD. Based on these data, the current proposal is aimed to address the following aspects: (1) To assess in patients with diverticulitis putative changes in the most important inhibitory neurotransmitter systems (NO, VIP) and whether other neurotrophic factors (GDNF family members, endothelin, neuregulin) display expression deficits. As neurotrophic factors significantly influence synaptic plasticity, markers of synaptic plasticity (synaptophysin, synaptobrevin, synaptotagmin, SNAP25) will indicate whether diverticulitis is associated with a synaptopathy. (2) The set of experiments so far carried out in patients with diverticulitis will also be conducted in patients with diverticulosis. If this collective reveals similar findings (e.g. hypoganglionosis, neurotransmitter disturbances, deficits of neurotrophic factors, synaptopathy), these data would support the hypothesis of underlying neuromuscular alterations being initially involved in the pathogenesis of DD. (3) The underlying pathomechanisms of neuromuscular changes detected in the human pathology will be further investigated in in vitro models. For this purpose, besides enteric nerve cell cultures we have established a model of cultured enteric smooth muscle cells. These in vitro models will allow to assess the influence of neurotrophic factors shown to be altered in DD on proliferation, differentiation and synaptic plasticity of enteric nerve cells as well as on structural and functional differentiation of enteric smooth muscle cells. The data obtained in the experiments proposed could revise traditional pathogenetic concepts of DD and identify enteric neuro-/myopathies as etiologic factors in DD which may allow to develop innovative concepts for prophylactic and (pharmaco-)therapeutic approaches.