IADR Abstract Archives
Hypoxia Modulates the Circadian Core Clock in Dental Pulp-derived Cells
Objectives: Circadian core clock genes are pace makers for a variety of functions in physiology and regeneration. Their role and regulation in the dental pulp, in particular under hypoxic conditions, is unknown. The aim of this study was to reveal if core clock genes are expressed in human dental pulp-derived cells and if the mRNA levels of these genes are modulated under hypoxic conditions or in the presence of hypoxia mimetic agent L-Mimosine (L-MIM).
Methods: Human dental pulp-derived cells (DPC) were cultured in 2D monolayers and 3D spheroids for 24h with and without hypoxia or L-MIM. RNA was isolated and mRNA levels of the circadian core clock genes Clock, Bmal1, Cry1, Cry2, Per1, Per2 and Per3 were evaluated via reverse transcription and quantitative PCR. Based on the results, time course experiments were performed in monolayer cultures for the target genes Clock, Cry1, Cry2 and Per3.
Results: All core clock genes, Clock, Bmal1, Cry1, Cry2, Per1, Per2 and Per3, were transcribed in DPC monolayer and spheroid cultures. Their specific expression is diversely modulated by hypoxia or L-MIM. In both models Clock, Cry1, Cry2 and Per3 were significantly downregulated by hypoxia or L-MIM. The time course experiments in monolayer cultures of human DPC showed that this modulation mainly affects the amplitude of mRNA production of these core clock genes.
Conclusions: Overall our results show that human DPC express clock core genes and that the expression levels can be modulated by hypoxia and the hypoxia mimetic agent L-MIM. These results suggest a role of the circadian clock in the response of the dental pulp to hypoxia.
Methods: Human dental pulp-derived cells (DPC) were cultured in 2D monolayers and 3D spheroids for 24h with and without hypoxia or L-MIM. RNA was isolated and mRNA levels of the circadian core clock genes Clock, Bmal1, Cry1, Cry2, Per1, Per2 and Per3 were evaluated via reverse transcription and quantitative PCR. Based on the results, time course experiments were performed in monolayer cultures for the target genes Clock, Cry1, Cry2 and Per3.
Results: All core clock genes, Clock, Bmal1, Cry1, Cry2, Per1, Per2 and Per3, were transcribed in DPC monolayer and spheroid cultures. Their specific expression is diversely modulated by hypoxia or L-MIM. In both models Clock, Cry1, Cry2 and Per3 were significantly downregulated by hypoxia or L-MIM. The time course experiments in monolayer cultures of human DPC showed that this modulation mainly affects the amplitude of mRNA production of these core clock genes.
Conclusions: Overall our results show that human DPC express clock core genes and that the expression levels can be modulated by hypoxia and the hypoxia mimetic agent L-MIM. These results suggest a role of the circadian clock in the response of the dental pulp to hypoxia.