Hong Qian, DDS, PhD,* Xuepeng Chen, DDS, PhD,* Yingchun Bi, DDS, PhD,
Yan Wang, DDS, PhD, Yinzhong Duan, DDS, PhD, and Zuolin Jin, DDS, PhD
*Equally contribute to the manuscript.
Department of Orthodontics, College of Stomatology, The Fourth Military Medical University, Xi’an,
P. R. China
Purpose: This study was undertaken to determine the expression of interleukin-10 at protein level in human dental follicle cells and the effect of interleukin-10 on gene expression of osteoprotegerin and receptor activator of nuclear factor-kappa B ligand.
Materials and Methods: Primary human dental follicle cells were cultured. The expression of interleukin-10 at protein level was detected by immunocytochemistry. The gene expression of osteoprotegerin and receptor activator of nuclear factor-kappa B ligand treated with 0, 5, 10, 25, 50, and 100 ng/mL interleukin-10 for 1 hour (for osteoprotegerin) or for 6 hours (for receptor activator of nuclear factor-kappa B ligand) was examined by reverse transcription-polymerase chain reaction. Osteoprotegerin secretion treated with 25 ng/mL interleukin-10 at 0, 2, 4, 6, and 8 hours was examined by enzyme-linked immunosorbent assay.
Results: Interleukin-10 was expressed in human dental follicle cells. Interleukin-10 enhanced osteoprotegerin gene expression and secretion. In contrast, interleukin-10 suppressed receptor activator of nuclear factor-kappa B ligand gene expresson. Protein kinase C inhibitors, myristoylated protein kinase C peptide inhibitor and Go6983, decreased interleukin-10-induced osteoprotegerin, whereas protein kinase A inhibitors, cAMP- dependent protein kinase peptide inhibitor and KT5720, did not decrease it.
Conclusion: The molecular basis for interleukin-10 on the inhibition of osteoclastogenesis is by enhancement of osteoprotegerin gene expression and suppression of receptor activator of nuclear factor-kappa B ligand gene expression in human dental follicle cells. Interleukin-10-induced osteoprotegerin secretion was dependent on protein kinase C pathway. Interleukin-10 signaling may play an important role in the tooth eruption process. (Int Chin J Dent 2007; 7: 7-13.)
Key Words: dental follicle cell, interleukin-10, osteoprotegerin, protein kinase A, protein kinese C.