3. Comprehensive Analysis of Genes in Oral Mucosal Epithelium by Laser Microdissection

[Objective] The study of the junctional epithelium (JE), which has an attachment function could shed light on the workings of the regeneration of periodontal tissue and the prevention of the periodontal disease. However, the mechanism of the adhesion of the JE does not remain unexplained at a molecular level. Therefore, the purpose of the current study is to perform a comprehensive analysis of and search for the specific gene of the JE from the fresh frozen tissue section with laser microdissection and microarray. [Materials and Methods] Comprehensive analysis of genes in the JE and oral epithelium of postnatal 28-day-old female ICR mouse using laser microdissection, microarray, quantitative real-time reverse transcription-polymerase chain reaction and immunohistochemical analysis. [Results] Microarray analysis showed that the expression of several genes in the JE are higher than in the oral epithelium (OE). In particular, the level of Secretory Leukocyte Protease Inhibitor (Slpi) expression in the JE is 108-fold higher compared with the OE. Immunohistochemical analysis also showed that protein of SLPI is highly expressed in the JE. [Conclusion] We developed a method of making the fresh frozen tissue section and extraction of total RNA by laser microdissection. Furthermore, we found that SLPI is characteristically expressed in the JE. Our method provides a substantial advance in the development of the comprehensive analysis of genes in JE.