Enzymatic and proteomic salivary bio markers for erosion

牙齿腐蚀是由非细菌来源的酸引起的。特别是在经常暴露于外源性（饮食）或内源性（胃）酸的情况下，它会导致严重的缺陷、疼痛和功能障碍。虽然酸的影响已被明确地确定为病因因素，但酸暴露程度与腐蚀缺陷的严重程度之间往往没有关系。唾液被认为是一种重要的侵蚀保护因子，但到目前为止，没有证据表明诸如流量受损或缓冲能力低或pH值等参数与较高的侵蚀损失风险相关。然而，目前一项自己的初步研究结果显示，在饮食失调和慢性呕吐患者中，糜烂性病变的发生与特定蛋白水解酶的活性密切相关，突出了唾液酶作为调节因素的作用。目前尚不清楚这是否与饮食失调患者有关，或者是否也适用于反流疾病患者和饮食酸暴露患者。也没有研究过蛋白质的组成是否会因常规的酸撞击而改变。因此，本基础研究的目的是调查唾液中的蛋白水解酶活性是否会因定期侵蚀而改变，以及蛋白质组成是否会发生定性或定量的变化。应该评估这些变化是否可用作侵蚀风险的一般生物标志物。有内在（饮食失调；胃食管反流）和外在（饮食）酸暴露的受试者将被包括在内。目标标准是唾液中总蛋白含量的定量以及蛋白水解酶的活性（一般蛋白水解活性，胶原酶，胃蛋白酶，胰蛋白酶）；此外，还应分析唾液的蛋白质组。控制参数为流速、pH、缓冲能力以及过氧化物酶、溶菌酶和淀粉酶的酶活性。

Dental erosion is caused by acids of non-bacterial origin. Particularly in cases of frequent exposures to exogenous (dietary) or endogenous (gastric) acids, it can cause serious defects, pain and dysfunction. Though the impact of acids has clearly been identified as aetiological factor, there is often no relation between degree of acid exposure and severity of erosive defects. Saliva is assumed to be an important erosion protecting factor, but so far, there is no evidence that parameters like impaired flow rate or low buffering capacity or pH are associated with a higher risk of erosive loss. However, current results from an own pilot study revealed that in patients with eating disorders and chronic vomiting the occurrence of erosive lesions was strongly associated with the activity of specific proteolytic enzymes, highlighting the role of salivary enzymes as modulating factors. Whether this is specifically related to patients with eating disorders or whether this is also true for patients with reflux disease and with dietary acid exposures is unclear. It has also not been investigated whether the protein based composition is changed by the regular acid impact. The aim of this basic research study is therefore to investigate whether proteolytic enzyme activity in saliva is changed by regular erosive challenges and whether the protein composition changes qualitatively or quantitatively. It should be evaluated whether these changes are usable as a general biomarker for erosion risk. Subjects with intrinsic (eating disorders; gastro-oesophageal reflux) and extrinsic (dietary) acid exposures will be included. Target criteria are the quantification of the total protein content in saliva as well as the activity of proteolytic enzymes (general proteolytic activity, collagenase, pepsin, trypsin); in addition the proteome of the saliva should be analysed. Control parameters are flow rate, pH, buffering capacity, as well as enzyme activity of peroxidase, lysozyme and amylase.