Frenkel Erica Shapiro, Ribbeck Katharina
Biological Sciences in Dental Medicine, Harvard University, Cambridge, Massachusetts, USA Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
Appl Environ Microbiol. 2015 Jan;81(1):332-8. doi: 10.1128/AEM.02573-14. Epub 2014 Oct 24.
Understanding how the body's natural defenses function to protect the oral cavity from the myriad of bacteria that colonize its surfaces is an ongoing topic of research that can lead to breakthroughs in treatment and prevention. One key defense mechanism on all moist epithelial linings, such as the mouth, gastrointestinal tract, and lungs, is a layer of thick, well-hydrated mucus. The main gel-forming components of mucus are mucins, large glycoproteins that play a key role in host defense. This study focuses on elucidating the connection between MUC5B salivary mucins and dental caries, one of the most common oral diseases. Dental caries is predominantly caused by Streptococcus mutans attachment and biofilm formation on the tooth surface. Once S. mutans attaches to the tooth, it produces organic acids as metabolic by-products that dissolve tooth enamel, leading to cavity formation. We utilize CFU counts and fluorescence microscopy to quantitatively show that S. mutans attachment and biofilm formation are most robust in the presence of sucrose and that aqueous solutions of purified human MUC5B protect surfaces by acting as an antibiofouling agent in the presence of sucrose. In addition, we find that MUC5B does not alter S. mutans growth and decreases surface attachment and biofilm formation by maintaining S. mutans in the planktonic form. These insights point to the importance of salivary mucins in oral health and lead to a better understanding of how MUC5B could play a role in cavity prevention or diagnosis.
了解人体自然防御机制如何发挥作用以保护口腔免受定植于其表面的众多细菌侵害，是一个正在进行的研究课题，可能会在治疗和预防方面取得突破。在所有湿润的上皮衬里，如口腔、胃肠道和肺部，一种关键的防御机制是一层厚厚的、水分充足的黏液。黏液的主要凝胶形成成分是黏蛋白，即大型糖蛋白，在宿主防御中起关键作用。本研究聚焦于阐明唾液黏蛋白MUC5B与龋齿（最常见的口腔疾病之一）之间的联系。龋齿主要由变形链球菌在牙齿表面附着和形成生物膜引起。一旦变形链球菌附着在牙齿上，它会产生有机酸作为代谢副产物，溶解牙釉质，导致龋洞形成。我们利用菌落形成单位计数和荧光显微镜定量显示，在蔗糖存在的情况下，变形链球菌的附着和生物膜形成最为活跃，并且纯化的人MUC5B水溶液在蔗糖存在时作为抗生物污垢剂保护表面。此外，我们发现MUC5B不会改变变形链球菌的生长，而是通过使变形链球菌保持浮游形式来减少其表面附着和生物膜形成。这些见解表明唾液黏蛋白在口腔健康中的重要性，并有助于更好地理解MUC5B如何在龋齿预防或诊断中发挥作用。
