Study Of Methylglyoxal On The Regulated Gene Expression Patterns In Human Periodontal Ligament Fibroblasts

Objective: To analyze the differential gene expression in human periodontal ligament fibroblasts (HPDLFs) induced by methylglyoxal (MG) through gene chip technology. Methods: HPDLFs were isolated from healthy periodontal ligaments of subjects who undergoing tooth extraction for orthodontic treatment. The tissue was mechanically scraped from the surface of extracted tooth and cells were prepared by using tissue explant culture technique. The cells were grown in DMEM medium supplemented with 15% calf serum. Experiments were performed with cells from the fourth to the seventh passages. Cells were devided into two groups with density of 5 × 10~5 and 5×10~4 respectively. The cells were stimulated with MG (0.05-1.0mg/ml) for 24h and was stained with trypen-blue to exam the viability of cells. The optimal concentration of MG was determined as 0.1mg/ml for gene expression experiments. For differential gene expression study, HPDLFSs were grown in DMEM with or without designated MG for 24h. Total RNA of the MG stimulated cells and control cells were extracted and were reversely transcripted into cDNA which were labeled with cy3/cy5 markers. The differential gene expression in HPDLFs stimulated by MG was analyzed by using gene chip technology. Results: The viability of the cells was significantly decreased when treated with higher concentration of MG (0.5-1.0 mg/ml) when cell density was 5×10~5. In addition, from the gene expression profile analysis, 5 genes were upregulated and 3 genes were downregulated when cells were treated with MG. Further analysis demonstrated that those genes were related to apoptosis, and cancigenisis. Conclusion: MG has the cytotoxic effects on HPDLFs. Furthermore, MG could alter the gene expression of HPDLFs. Those inside information supported the vision that MG could be an virolant factor to induce periodontal diseases.