Differentiation of PDL Cells Cultured with High Glucose Media

Objectives: It is known that diabetes is associated with decreased bone mass, osteoporosis, and increased fracture rates. This study was designed to examine the effect of high concentrations of extracellular glucose on the differentiation of the periodontal ligament cells. For this purpose, changes of the alkaline phosphatase activity and protein synthesis of these cells were examined after incubation with high glucose media for 7, 14, 21, and 28 days.

Methods: The PDL cells were obtained by the explant culture method from healthy human periodontal ligament tissues. The cells were treated with 1,000 mg/L (control) and 4,500 mg/L of glucose (high glucose group) for 7, 14, 21, and 28 days. After the incubation, ALP assay was performed to examine the alkaline phosphate(ALP) activity. The expressions of type I collagen, osteopontin , and osteocalcin were examined by Western blot.

Results:

1. ALP activity of the cells was increased by the high concentrations of extracellular glucose.

2. Osteopontin and osteocalcin synthesis were decreased by the high concentrations of extracellular glucose.

3. Type I collagen synthesis was not changed by the high concentrations of extracellular glucose.

Conclusions: High concentrations of extracellular glucose stimulate the early differentiation process like alkaline phosphatase activity, but inhibit the persistent process of the synthesis of matrix proteins like osteocalcin and osteopontin. These results suggest that high concentrations of extracellular glucose may inhibit the formation and remodeling of periodontal ligament and alveolar bone.