Leptin is one of the adipocytokines produced from adi- pose tissue but its functions in periodontal tissue have not previously been investigated. In our current study, we exa- mined the effects of leptin on the expression of interleukin (IL)-6 and IL-8 in periodontal ligament (PDL) cells and gingival fibroblasts. Leptin receptor expression was evalua- ted by RT-PCR and the production of cytokines was mea- sured by ELISA. The phosphorylation of Akt and Erk1/2 was assessed by western blotting. mRNA of long and short form leptin receptors were detected in both PDL cells and gingival fibroblasts. Leptin was found to increase the pro- duction of IL-6 and IL-8 in both of these cell types, an effect which was not blocked by polymyxin B, an inhibitor of lipopolysaccharide (LPS). Leptin did not alter the pro- duction of IL-6 and IL-8 induced by LPS in PDL cells but increased Akt and Erk1/2 phosphorylation in these cells. These results suggest that leptin acts as an inducer of IL-6 and IL-8 in PDL cells and gingival fibroblasts.

• Hong-Gyu Park(Oral Cancer Research Institute, Yonsei University College of Dentistry)
• Ji-Hye Kim(Department of Applied Life Science, The Graduate School, Yonsei University)
• Jeong-Heon Cha(Oral Cancer Research Institute, Yonsei University College of Dentistry, Department of Applied Life Science, The Graduate School, Yonsei University, Department of Oral Biology, Yonsei University College of Dentistry)
• Eun-Jung Bak(Department of Oral Biology, Yonsei University College of Dentistry)
• Yun-Jung Yoo(Oral Cancer Research Institute, Yonsei University College of Dentistry, Department of Applied Life Science, The Graduate School, Yonsei University) Correspondence