Leptin expression in healthy and inflamed human dental pulp

Martin-Gonzalez J, Sanchez-Jimenez F, Perez-Perez A, Carmona-Fernandez A, Sanchez-Margalet V, Segura-Egea JJ. Leptin expression in healthy and inflamed human dental pulp. International Endodontic Journal, 46, 442-448, 2013. Aim To investigate the expression of leptin in healthy and inflamed human dental pulp. Methodology Twenty-one pulp samples were obtained from freshly caries- and restoration-free extracted human third molars. In seven-third molars (inflamed pulp group), inflammation was induced prior to extraction. Pulp samples were processed, and leptin expression was determined by quantitative real-time PCR (qRT-PCR) and the amount of leptin by immunoblot. Results All healthy and inflamed dental pulp samples expressed leptin. Western blot analysis revealed the presence of a protein with an apparent molecular weight of similar to 16 kDa in human dental pulp, which corresponds to the estimated molecular weight of leptin. The expression of leptin mRNA in dental pulp was confirmed by qRT-PCR analysis, and the size of the amplified fragments (296 bp for leptin and 194bp for cyclophilin) was confirmed by agarose gel electrophoresis. The expression of leptin in the inflamed pulp group was significantly greater (P<0.05) than in healthy teeth. The relative amount of leptin in inflamed pulps was almost twice than in healthy pulps. Conclusions For the first time, the presence of leptin in human dental pulp tissues has been demonstrated. The upregulation of leptin expression in inflamed pulp samples suggests that leptin can play a role in pulpal inflammatory and immune responses.