Insulin‐like growth factor‐binding protein‐2 and ‐3 in gingival crevicular fluid

Takenouchi Y, Ohshima M, Yamaguchi Y, Nishida T, Senda N, Idesawa M, Otsuka K, Ito K. Insulin‐like growth factor‐binding protein‐2 and ‐3 in gingival crevicular fluid. J Periodont Res 2010; 45: 803–808. © 2010 John Wiley & Sons A/S Background and Objective: Insulin‐like growth factor‐binding proteins (IGFBPs) are crucial regulators of insulin‐like growth factor (IGF). They enhance or inhibit IGF functions, but also exhibit IGF‐independent effects. In a previous study, we detected, qualitatively, IGFBP‐2 and ‐3 in gingival crevicular fluid using a cytokine antibody array. Here we extended these results using an ELISA to determine the concentrations of IGFBP‐2 and ‐3 in gingival crevicular fluid. In addition, we explored whether the expression of IGFBP‐2 and IGFBP‐3 correlates with periodontal disease severity. Material and Methods: Gingival crevicular fluid samples from 92 sites of 12 patients affected with periodontal disease and from 100 sites of 19 healthy volunteers, were collected, divided into two groups and analyzed by ELISA for IGFBP‐2 and ‐3 expression. The potential correlation among probing depth, gingival index and the concentrations of IGFBP‐2 and ‐3 was analyzed. Results: Positive correlations were observed between the concentration of IGFBP‐2 and probing depth and gingival index, but not for IGFBP‐3. The IGFBP‐2 concentrations at bleeding on probing‐positive sites and at sites with a probing depth of ≥ 4 mm were higher than at bleeding on probing‐negative sites and at sites with a probing depth of ≤ 3 mm. Conclusion: These results indicate that IGFBP‐2 is a potential novel marker for periodontal disease progression. As IGFBP‐2 modulates bone metabolism and cell migration, IGFBP‐2 in the gingival crevicular fluid may reflect periodontal disease activity.     

Effects of adenoviral‐mediated coexpression of bone morphogenetic protein‐7 and insulin‐like growth factor‐1 on human periodontal ligament cells

Yang L, Zhang Y, Dong R, Peng L, Liu X, Wang Y, Cheng X. Effects of adenoviral‐mediated coexpression of bone morphogenetic protein‐7 and insulin‐like growth factor‐1 on human periodontal ligament cells. J Periodont Res 2010; 45: 532–540. © 2010 John Wiley & Sons A/S Background and Objective: Bone morphogenetic protein‐7 (BMP‐7) and insulin‐like growth factor‐1 (IGF‐1) are important in periodontal reconstruction. However, their synergistic effect in periodontal regeneration by gene delivery has not been reported. In this study, gene delivery of these two growth factors to human periodontal ligament cells (hPDLCs) was examined for its effects on cell proliferation and differentiation. Material and Methods: Recombinant adenoviruses containing both human BMP‐7 and IGF‐1 cDNA created by introducing the internal ribosome entry site (IRES) sequence were used to transfer the genes into hPDLCs. 3‐(4,5‐Dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay and cell cycle analysis were used to observe their effects on cell proliferation, while alkaline phosphatase activity measurement, RT‐PCR and in vivo tests were conducted to investigate their effects on cell differentiation. Results: The proliferation of hPDLCs transduced by adenoviruses coexpressing BMP‐7 and IGF‐1 was suppressed while their differentiation ability was enhanced. There was a synergism of BMP‐7 and IGF‐1 in up‐regulating alkaline phosphatase activity and mRNA levels of collagen type I and Runx2. Implantation in vivo with scaffolds illustrated that the transduced cells exhibited osteogenic differentiation and formed bone‐like structures. Conclusion: The combined delivery of BMP‐7 and IGF‐1 genes using an IRES‐based strategy synergistically enhanced differentiation of hPDLCs. It is suggested that this could be a new potential method in gene therapy for periodontal reconstruction.