“双效应”釉基质蛋白功能多肽靶向防治龋病的应用基础研究

Dental caries is the most prevalent bacterial infectious oral disease in the world, posing a serious threat to oral and general health. Effective caries prevention and treatment depend on inhibiting cariogenic bacteria and promoting the re- mineralization of initial caries. Experiments have been carried out by us to obtain the functional peptides from enamel matrix proteins(EMPs), and it has been proved for the first time that functional peptides based on EMPs can inhibit the de- mineralization of enamel caries and enhance the remineralization of initial enamel carious lesion, the functional peptides from EMPs have shown the "single-acting" potential of anticaries. Until now however, the application methods of functional peptide have not been discussed..This project will develop and test "dual-acting" functional EMP peptides for the purpose of promoting the anticaries potential of "single-acting" functional EMP peptides. First, molecular biotechnology will be used to modify the structure of "single-acting"functional peptides, using antimicrobial peptides (AMPs) of cario- genic bacteria as a reference. Then "dual-acting" EMP functional peptides will be observed for their ability in inhibiting cariogenic bacteria and promoting the remineralization of initial caries. Parameters of "dual-acting" peptide delivery will be systematically optimized, including the peptide carrier, the form of calcium and phosphate used, and the target interface between "dual-acting" peptide and dental caries.Finally,the optimized parameters will be used to set up a clinical application of "dual-acting" functional EMP peptides to prevent and treat the dental caries, and the effectiveness and safety of this application will be evaluated by the means of animal model..This project may improve the ability of functional EMP peptides to prevent and treat dental caries, and develop the practical clinic application of functional EMP peptides. Thus the project will lay the solid foundation for breaking new ground in caries prevention and treatment that is safe and effective. And the project also will provide the independent intellectual property rights on anticarious functional EMP peptides and their application.

龋病是人类最常见的口腔疾病，严重危害口腔及全身健康，抑制致龋菌和促进再矿化是龋病防治的两个重要方面。课题组前期在国内外首次获得了具有促进牙釉质龋再矿化作用的"单效应"釉基质蛋白功能多肽，论证了其与龋病防治的相关性，然而目前釉基质蛋白在龋病防治领域的应用仍是空白。本项目在前期基础上，首次提出釉基质蛋白"双效应"防龋思想，借鉴致龋菌抗菌肽结构，利用分子生物学技术，改良"单效应"釉基质蛋白功能多肽结构，通过防龋活性筛选实验体系，获得具有抑制致龋菌、促进再矿化作用的"双效应"防龋釉基质蛋白功能多肽，并通过研究其应用载体、钙磷供给形式、靶向作用界面，首次构建釉基质蛋白功能多肽靶向防龋的应用模型，评价其有效性和安全性。本项目的实施将显著提高釉基质蛋白功能多肽的防龋效果，为其防龋应用提供理论依据，为其临床应用提供参考，为开辟一条新的安全有效的具有自主知识产权的龋病防治途径奠定基础。

龋病是人类最常见的口腔疾病，严重危害口腔及全身健康，抑制致龋菌和促进再矿化是龋病防治的两个重要方面，探索安全有效的龋病防治措施仍然是当今世界龋病研究领域的工作重点。项目负责人长期从事龋病防治研究，在国内外首次提出釉基质蛋白功能多肽防龋思想，在前期实验中获得具有抑制釉质龋脱矿、促进其再矿化潜能的釉基质蛋白功能多肽。为进一步提高功能多肽的防龋效果，本项目从龋病防治的致龋菌抑制和再矿化促进两个方面出发，提出借鉴致龋菌抗菌肽结构思想，对前期获得的矿化“单效应”防龋釉基质蛋白功能多肽进行结构改良，使其皆具促进再矿化和抑制致龋菌的“双效应”防龋能力，这对提高釉基质蛋白功能多肽防龋效果具有重要意义。同时，本项目对“双效应”釉基质蛋白功能多肽应用载体、作用界面、钙磷供给形式进行研究，为釉基质蛋白功能多肽防龋临床应用提供依据。本项目研究结果主要包括：①获得具有原创性的α-螺旋抗菌肽GH12，改良前期“单效应”釉基质蛋白功能多肽结构，通过防龋活性筛选实验，获得了具有细菌学和再矿化“双效应”防龋作用的釉基质蛋白功能多肽SSSSSS-GH12和TKRQQVV-GH12；②研究了“双效应”釉基质蛋白功能多肽SSSSSS-GH12和TKRQQVV-GH12的应用载体、多肽与釉质龋作用界面、钙磷供给形式，结果以PGA为载体的功能多肽SSSSSS-GH12和TKRQQVV-GH12在钙、磷溶液型人工唾液效果和凝胶型人工唾液中具有较好的防龋效果；③动物实验发现，功能多肽作用下大鼠全身状况良好，进食活动正常，口腔黏膜未见异常，各组大鼠体重无明显差异。NaF组和功能多肽组的菌斑指数明显低于去离子水组，去离子水处理的大鼠在光滑面龋和窝沟龋Keyes评分明显高于用NaF和功能多肽处理的大鼠，证实了“双效应”釉基质蛋白功能多肽SSSSSS-GH12的有效性和安全性，。通过本项目的实施，充分提高了前期釉基质蛋白功能多肽防治龋病的效果，也为釉基质蛋白功能多肽靶向防治龋病的临床应用提供可能，为开辟一条新的安全有效的具有自主知识产权的龋病防治途径奠定了基础。