Enzymatic and proteomic salivary bio markers for erosion

牙齿腐蚀是由非细菌来源的酸引起的。特别是在经常接触外源性(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。尽管酸的影响已被明确地确定为致病因素，但酸暴露的程度与腐蚀性缺陷的严重程度通常没有关系。唾液被认为是一个重要的侵蚀保护因素，但到目前为止，还没有证据表明流速受损或缓冲能力或pH值低等参数与侵蚀损失的风险更高相关。然而，目前自己的一项试点研究结果显示，在饮食失调和慢性呕吐的患者中，腐蚀性病变的发生与特定的蛋白水解酶的活性密切相关，这突出了唾液酶作为调节因素的作用。这是否与饮食失调的患者特别相关，或者这是否也适用于反流病患者和饮食中的酸暴露，目前尚不清楚。也没有研究蛋白质的组成是否会因为有规律的酸冲击而改变。因此，这项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常规的侵蚀挑战而改变，以及蛋白质的组成是否会发生定性或定量的变化。应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(进食障碍；胃食道反流)和外源性(饮食)酸暴露的受试者将被包括在内。目标标准是量化唾液中的总蛋白含量以及蛋白水解酶的活性(一般蛋白分解活性、胶原酶、胃酶、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值、缓冲容量以及过氧化物酶、溶菌酶和淀粉酶活性。

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.