The Application of LC-MS/MS Technology for Proteomic Analysis of Gingival Tissue: a Pilot Study

Aim: The aim of this study was to find an optimal method to identify maximal number of proteins from human gingival tissue samples in a patient with aggressive periodontitis using label-free quantitative liquid chromatography mass spectrometry technology (LC-MS/MS), and to compare proteome of healthy and diseased gingival tissue samples. Materials and methods: Four gingival tissue samples (2 healthy, 2 diseased) were obtained from a nonsmoking female patient suffering from severe generalized aggressive periodontitis. Proteins from the tissue lysate were separated by 1D gel electrophoresis, in gel digested, measured by nano-scale HPLC system coupled to a mass spectrometer through a nano-electrospray ionization source. Raw data were processed by MaxQuant software. Results: Label-free quantitative LC-MS/MS analysis together with sample preparation, 1D gel electrophoresis and in-gel digestion showed to be an effective method for the proteome analysis of the gingival periodontal tissues. A total of 2429 proteins were identified and quantified. Among proteins upregulated in disease were: Ig gamma-1 chain C region, Ig kappa chain C region, Ig gamma-3 chain C region, and among downregulated proteins in the disease were: Desmoplakin, annexins, S100-A8/A9 proteins, and keratins. Conclusions: This pilot study is providing a novel insight into the protein profiles of gingival healthy and diseased tissues, which may contribute to the improvements in diagnosis, prognosis and better understanding of aggressive periodontitis pathogenesis. LC-MS/MS technology proved to be an effective method for the proteome analysis of the gingival tissues.