Stemness Properties and Differentiation of HPDLFs in Different Glucose Conditions

Objectives: The objective of this study was to study the stemness properties and differentiation capability of human periodontal ligament fibroblasts (HPDLFs) in different glucose condition.
Methods: HPDLFs were characterized as mesenchymal stem cells by flow cytometry and differentiation assay. They were studied for the stemness gene expression and the differentiation capability by induction with osteogenic and adipogenic medium in different glucose concentration media. Stemness gene expression was analysed by qRT-PCR, alkaline phosphatase activity was performed by spectrophotometric method and nodule formation was determined on day 28 using alizarin Red S. Statistical analysis was tested using One Way ANOVA and multiple comparisons at p<0.05.
Results: HPDLFs expressed CD73, CD90, CD105 and CD29 and showed the capacity to differentiate into osteoblast and adipocyte lineage. Gene expression analysis showed that the embryonic stem cell markers which are NANOG, OCT4 and SOX2 were significantly upregulated in high glucose condition. The expression of mesenchymal stem cell marker genes STRO1 and CD166 was also higher in high glucose medium than in low glucose medium. High glucose medium also increased alkaline phosphatase activity of cells by day 14 and increased the number of calcified nodules by day 28. Periostin, a specific protein in periodontal ligament was also increased in its expression in osteogenic medium containing high glucose concentration.
Conclusions: The results showed that high glucose concentration could enhance the stemness properties of HPDLFs by increasing the stem cell markers expression and activate osteogenic differentiation of these cells. The effect of glucose concentration on these HPDLFs may lead to more understanding about periodontal tissue regeneration in periodontal diseases in diabetic patients.