Background

The formation of dental plaque and its involvement in the pathogenesis of periodontitis is a topic of intense interest given the high prevalence of periodontitis in humans. Even though calcium-based particles play an active role in both dental plaque formation and periodontitis, few publications describe the physical-chemical properties of these particles.

Methods

Saliva samples were collected from healthy volunteers. From these samples, saliva-derived particles were isolated and stained for calcium using calcein or Fluo-4. The salivary particles were also subjected to characterization by flow cytometry and immunoblotting. Internalization of calcein-labeled salivary particles by gingival epithelial cells was visualized by confocal microscopy.

Results

We found that calcium-based salivary particles from healthy volunteers varied greatly in size but were enriched in particles of sizes at or greater than 1.5 μm. Immunoblotting analysis of the salivary particles identified several proteins including albumin, fetuin-A, and statherin, which have been found in calcium phosphate particles from other tissues or are known to modulate calcium homeostasis in saliva. In addition, calcium particles were internalized by both gingival epithelial cells and monocyte-derived macrophages.

Conclusion

Salivary calcium particles were enriched in the micrometer range, internalized by gingival epithelial cells, and contain albumin, fetuin-A and statherin, regulators of particle formation. These characteristics of the calcium-based salivary particles and their biological activities provide a basis for further studies to understand the molecular basis for pathogenesis of periodontitis.

中文翻译：

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唾液钙颗粒的物理特性及其与牙龈上皮的相互作用

背景

鉴于人类牙周炎的高患病率，牙菌斑的形成及其在牙周炎发病机制中的作用是一个备受关注的话题。尽管钙基颗粒在牙菌斑形成和牙周炎中都发挥着积极作用，但很少有出版物描述这些颗粒的物理化学性质。

方法

唾液样本取自健康志愿者。从这些样品中，分离出唾液衍生的颗粒，并使用 calcein 或 Fluo-4 对钙进行染色。还通过流式细胞术和免疫印迹对唾液颗粒进行表征。通过共聚焦显微镜观察牙龈上皮细胞对钙黄绿素标记的唾液颗粒的内化。

结果

我们发现来自健康志愿者的钙基唾液颗粒大小差异很大，但富含大小为或大于 1.5 μm 的颗粒。唾液颗粒的免疫印迹分析鉴定了几种蛋白质，包括白蛋白、胎球蛋白-A 和 statherin，这些蛋白质已在其他组织的磷酸钙颗粒中发现或已知可调节唾液中的钙稳态。此外，钙颗粒被牙龈上皮细胞和单核细胞衍生的巨噬细胞内化。

结论

唾液钙颗粒在微米范围内富集，被牙龈上皮细胞内化，并含有白蛋白、胎球蛋白-A 和 statherin，它们是颗粒形成的调节剂。钙基唾液颗粒的这些特性及其生物活性为进一步研究了解牙周炎发病的分子基础提供了基础。