The Influence Of Insulin On The Bioactivity Of Human Periodontal Ligament Fibroblasts In High Glucose Environment:In Vitro Study

Objective:To study the relationship between the development of parodontopathy and blood glucose level, find out theeffectivemethodto controlling cell proliferation and apoptosis, and provide new ideas for clinical treatment of chronic periodontitis in diabetes patients., by observing the influence of insulin (INS) on the cell proliferation of human periodontal ligament fibroblasts (hPDLFs) and the expression level of tumor necrosis factor-α(TNF-a), interleukin-1β(IL-1β), interleukin-6 (IL-6) and Osteocalcin (OCN).Methods:Orthodontic pulling premolars of healthy populations were used in vitro for cultivation of human periodontal ligament fibroblasts (HPDLFs) insulin (INS) at the concentration of 10-6 mol/L was chosen to set up five experimental groups: group A (normal control) (5.5 mmol//L), group B (middle high sugar) (25 mmol/L glucose), group C (sugar group) (45 mmol/L glucose), group B + INS, group C + INS. Human periodontal ligament fibroblasts (HPDLFs) were stimulated respectively and flow cytometry instrument was used to detect human periodontal ligament fibroblasts (HPDLFs). Cell proliferation and apoptosis were stimulated at different concentrations of high sugar. Using enzyme-linked immunosorbent (ELISA), human periodontal ligament fibroblasts tumor necrosis factor-a(TNF-a), interleukin-1β(IL-1β), interleukin-6 (IL-6) and on Osteocalcin (OCN) expression level stimulated at different concentrations of high sugar were detected. SPSS 17.0 software package was used for statistical analysis of data via variance test while the experimental results were expressed in X ±s, (p< 0.05) for statistical significance.Results:1. Effect of different sugar concentrations on periodontal ligament cell proliferation activity. Group (5.5 mmol/L Glu) had no significant effect on the periodontal ligament fibroblasts proliferation In Group B(25 mmol/L Glu) Glu started to inhibit periodontal ligament fibroblasts proliferation in a concentration-dependent manner, cell growth was more retarded than in the normal group, while the rate of cell apoptosis increased. In Group C (45 mmol/L Glu) the most significant effect was observed on periodontal ligament fibroblasts proliferation, cell growth was slowed down, and cell apoptosis rate increased significantly.In high sugar group (25 mmol/L Glu) adding insulin accelerated the recovery of human periodontal ligament fibroblasts cells, significantly reduced the apoptosis rate, It but still lower than in the normal sugar concentration group.In C + INS group, the addition of insulin decreased the periodontal ligament fibroblast growth rate and apoptosis rate,but significantly lower than in the normal sugar t and middle high sugar group.In these five groups, the suppression of the periodontal ligament fibroblasts proliferation, cell growth, and the cell apoptosis rate was of statistical significance (p< 0.05).2. Effect of different sugar concentrations on the expression of periodontal ligament cells TNF-α, IL-1β, IL-6 and OCN.In Group A (5.5 mmol/L Glu) the expression of TNF-α, IL-1β, IL-6 and OCN was lower than in middle high sugar group and high sugar group; the expression of OCN is was higher than in middle high sugar group and high sugar group.In the middle high sugar group B (25 mmol/L Glu), the expression of TNF-α, IL-1β, IL-6 and OCN was higher than in normal group; the expression of OCN was lower than in normal group.In the high sugar group C (45 mmol/L Glu) the expression of TNF-α, IL-1β, IL-6 and OCN is was significantly higher than in normal group and in middle high sugar group; the expression of OCN was significantly lower than in normal group and in middle high sugar group.In B + INS group and middle high sugar group (25 mmol/L Glu) the expression of TNF-α, IL-1β, IL-6 and OCN was still higher than in normal groups after insulin was added; the expression of OCN was raised.In C + INS group, the expression of TNF-α, IL-1β, IL-6 and OCN was significantly higher than in normal group and in middle sugar group; the expression of OCN was raised.The difference in the expression of TNF-α, IL-1β, IL-6 and OCN between the five groups was of statistical significance (p< 0.05)Conclusion;A high sugar environment can significantly inhibit the periodontal ligament fibroblasts proliferation. HPDLFs can induce apoptosis andincrease the expression of TNF-α, IL-1β, IL-6 and OCN. INS can significantly regulation the sugar environment induced by inhibition of the periodontal ligament fibroblasts proliferation, apoptosis and TNF-α, IL-1β, IL-6 and OCN.