Effects of TGF-β1 on interleukin profile of human dental pulp and odontoblasts
Abstract Transforming growth factor-beta 1 (TGF-β1) is the most extensively studied growth factor in dentin–pulp complex, with pleiotropic effects on pulp response and healing. Our main objective was to analyze the expression profile of pulp tissue and odontoblasts, and the effects of TGF-β1 on these profiles in cultured human pulp and odontoblasts with a specific interest in the anti- and pro-inflammatory cytokines. For that purpose, pulps and odontoblasts were cultured for different time periods, and microarray was performed to both cultured and native samples. Of cytokines, various interleukins (IL) were confirmed by RT-PCR, and in +/− TGF-β1 treated pulps also by antibody array. Pro-inflammatory IL-7, -12α and -16 mRNAs were detected in native pulp. The expression levels of pro-inflammatory IL-1α, -1β, -6 and -8 were clearly induced after TGF-β1 treatment, while no anti-inflammatory cytokines were induced. Of all pulpal interleukins analyzed IL-6 and -8 were present at the highest levels in conditioned pulp tissue media. In native odontoblasts pro-inflammatory IL-6 and -7 mRNAs were detected, and in cultured odontoblasts pro-inflammatory IL-8 mRNA showed over 20-fold transient induction after TGF-β1 treatment. Our results demonstrate that TGF-β1 is a potent regulator of pro-inflammatory responses and defensive reactions in dentin–pulp complex.