DISTINCT SALIVARY PROTEOMIC PATTERNS AS SIGNATURE FOR MOLAR INCISOR HYPOMINERALIZATION STAGES

Saliva is a rich-bodily fluid with recognized clinical diagnosis roles and this research aimed at investigating if there is any change in the salivary proteome signatures of MIH children with distinct degrees of severity. Fifty schoolers (6-10 years) were equally assigned into the following groups: Group 1 (Control group - Healthy teeth), Group 2 (Mild MIH with white/creamy opacity and free of caries), Group 3 (Mild MIH with yellow/brown opacity and free of caries), Group 4 (Severe MIH with white/creamy, yellow/brown opacities including post-eruptive fracture and free of caries), Group 5 (Severe MIH with white/creamy, yellow/brown opacities, post-eruptive fracture, and caries). Unstimulated saliva samples were collected and later explored using mass spectrometry analysis. In total, 6,471 proteins were found, 5,073 exclusively from MIH children, and 778 overlapping among the different degrees of the disturb. The Biological Pathways displayed distinct patterns among the groups, being different according to the degrees of MIH. Gene-Odontology differences might not be verified regarding the biological processes and cellular components. Conversely, with respect to molecular function, alterations among groups were evident, with the presence of proteins that would contribute to MIH in children with the severe condition (i.e, calcium ion binding, microtubule binding, platelet-derived growth factor binding). In conclusion, the results of this study support important salivary proteomic changes in MIH children, according to distinct degrees of severity, reinforcing the interplay between the clinical aspects of hypomineralization (white/yellow opacities/enamel breakdown) and changes in the salivary proteome.

唾液是一种成分丰富的体液，已被广泛认可其临床诊断价值。本研究旨在探究不同严重程度的磨牙切牙釉质发育不全（Molar Incisor Hypomineralization，MIH）患儿的唾液蛋白质组（salivary proteome）特征是否存在差异。本研究纳入50名6~10岁的学龄儿童，将其平均分为以下5组：第1组（对照组：牙体健康的儿童）；第2组（轻度MIH组：仅存在白色/乳脂状釉质混浊，无龋坏）；第3组（轻度MIH组：仅存在黄色/棕色釉质混浊，无龋坏）；第4组（重度MIH组：存在白色/乳脂状、黄色/棕色釉质混浊，伴萌出后牙折，无龋坏）；第5组（重度MIH组：存在白色/乳脂状、黄色/棕色釉质混浊，伴萌出后牙折，且合并龋坏）。研究人员采集了所有受试者的非刺激性唾液样本，随后通过质谱分析（mass spectrometry）进行检测。本次研究共鉴定出6471种蛋白质，其中5073种仅在MIH患儿样本中检出，778种在不同严重程度的MIH患儿样本中均有检出。各组的生物学通路（Biological Pathways）呈现出截然不同的表达模式，且该差异与MIH的严重程度密切相关。在生物学过程与细胞组分层面，各组间的基因本体（Gene Ontology，GO）富集差异未得到有效验证。反之，在分子功能层面，各组间的蛋白质表达差异显著，重症MIH患儿样本中存在与疾病发生相关的蛋白质（例如钙离子结合蛋白、微管结合蛋白、血小板衍生生长因子结合蛋白）。综上，本研究结果证实，不同严重程度的MIH患儿的唾液蛋白质组均存在显著变化，进一步印证了牙釉质矿化不全（hypomineralization）的临床特征（白色/黄色釉质混浊、牙釉质破损）与唾液蛋白质组变化之间的内在关联。