Busso Carlos S, Guidry Jessie J, Gonzalez Jhanis J, Zorba Vassilia, Son Leslie S, Winsauer Peter J, Walvekar Rohan R
1Department of Otolaryngology and Bio-communication, Louisiana State University Medical School Health Sciences Center, 533 Bolivar St. Suite 566, New Orleans, LA 70112 USA.
2Department of Biochemistry and Molecular Biology, and The LSUHSC Proteomics Facility Core, Louisiana State University Medical School Health Sciences Center, 533 Bolivar St. Suite 331, New Orleans, LA 70112 USA.
Clin Proteomics. 2020 Mar 31;17:12. doi: 10.1186/s12014-020-09275-w. eCollection 2020.
Sialolithiasis or salivary gland stones are associated with high clinical morbidity. The advances in the treatment of sialolithiasis has been limited, however, by our understanding of their composition. More specifically, there is little information regarding the formation and composition of the protein matrix, the role of mineralogical deposition, or the contributions of cell epithelium and secretions from the salivary glands. A better understanding of these stone characteristics could pave the way for future non-invasive treatment strategies.
Twenty-nine high-quality ductal stone samples were analyzed. The preparation included successive washings to avoid contamination from saliva and blood. The sialoliths were macerated in liquid nitrogen and the maceration was subjected to a sequential, four-step, protein extraction. The four fractions were pooled together, and a standardized aliquot was subjected to tandem liquid chromatography mass spectrometry (LCMS). The data output was subjected to a basic descriptive statistical analysis for parametric confirmation and a subsequent G.O.-KEGG data base functional analysis and classification for biological interpretation.
The LC-MS output detected 6934 proteins, 824 of which were unique for individual stones. An example of our sialolith protein data is available via ProteomeXchange with the identifier PXD012422. More important, the sialoliths averaged 53% homology with bone-forming proteins that served as a standard comparison, which favorably compared with 62% homology identified among all sialolith sample proteins. The non-homologous protein fraction had a highly variable protein identity. The G.O.-KEGG functional analysis indicated that extracellular exosomes are a primary cellular component in sialolithiasis. Light and electron microscopy also confirmed the presence of exosomal-like features and the presence of intracellular microcrystals.
Sialolith formation presents similarities with the hyperoxaluria that forms kidney stones, which suggests the possibility of a common origin. Further verification of a common origin could fundamentally change the way in which lithiasis is studied and treated.
涎石病或唾液腺结石与较高的临床发病率相关。然而，由于我们对其成分的了解，涎石病治疗方面的进展一直有限。更具体地说，关于蛋白质基质的形成和组成、矿物沉积的作用或细胞上皮以及唾液腺分泌物的贡献，几乎没有相关信息。更好地了解这些结石特征可为未来的非侵入性治疗策略铺平道路。
对29个高质量的导管结石样本进行了分析。样本制备包括连续冲洗以避免唾液和血液污染。将涎石在液氮中浸泡，浸泡物经过连续的四步蛋白质提取。将这四个部分合并在一起，取标准化的等分试样进行串联液相色谱质谱分析（LCMS）。数据输出进行基本描述性统计分析以进行参数确认，随后进行基因本体论-京都基因与基因组百科全书（G.O.-KEGG）数据库功能分析和分类以进行生物学解释。
LC-MS输出检测到6934种蛋白质，其中824种是单个结石所特有的。我们的涎石蛋白质数据示例可通过蛋白质组交换库获取，标识符为PXD012422。更重要的是，与作为标准对照的骨形成蛋白相比，涎石平均有53%的同源性，这与所有涎石样本蛋白质中确定的62%同源性相比更具优势。非同源蛋白质部分具有高度可变的蛋白质同一性。G.O.-KEGG功能分析表明，细胞外囊泡是涎石病中的主要细胞成分。光学显微镜和电子显微镜也证实了类似囊泡特征的存在以及细胞内微晶的存在。
涎石形成与形成肾结石的高草酸尿症存在相似之处，这表明可能有共同的起源。对共同起源的进一步验证可能会从根本上改变结石病的研究和治疗方式。
