RESUMO
INTRODUCTION: Endogenous cannabinoids (endocannabinoids [eCBs]) have been shown to have a multitude of functions including neurotransmission and immune modulatory effects. This study aimed to evaluate if stem cells of the apical papilla (SCAP) express the receptors and enzymes of the endocannabinoid system (ECS) and whether eCBs regulate their proliferation and mineralization potential. METHODS: Gene expression of the main components of the ECS and transient receptor potential vanilloid 1 (TRPV1) was evaluated in SCAP cultures. SCAP were treated with 2 concentrations of eCBs and/or capsazepine, a TRPV1 antagonist. SCAP viability was evaluated after 1, 4, and 7 days. Osteogenic differentiation was assessed after 14 days, and the gene expression of mineralization markers was assessed after 7 days. RESULTS: The enzymes of ECS and TRPV1 but not the cannabinoid receptors (cannabinoid receptors 1 and 2) were expressed in SCAP. Anandamide, 2-arachidonoylglycerol, and N-arachidonoylphenolamine (AM-404) reduced SCAP viability in all experimental periods at the highest concentration compared with the group with no treatment. Anandamide and AM-404 did not inhibit SCAP differentiation potential, but 2-arachidonoylglycerol at the highest concentration did. SCAP treated with AM-404 presented a down-regulation in gene expression of alkaline phosphatase (ALP), dentin matrix protein 1 (DMP-1), and dentin sialophosphoprotein (DSPP) compared with the proliferation medium group but not with control group. CONCLUSIONS: SCAP expressed the genes of the main components of ECS and TRPV1, and eCBs can affect SCAP viability, mineralization, and gene expression.
Assuntos
Papila Dentária , Osteogênese , Diferenciação Celular , Endocanabinoides , Receptores de Canabinoides , Células-Tronco , Canais de Cátion TRPV/genéticaRESUMO
INTRODUCTION: Root canal treatment of immature necrotic teeth is a major challenge in current endodontics. The effect of inflammatory mediators, such as prostaglandin, on the modulation of stem cells of the apical papilla (SCAP) is not completely understood. The aim of this study was to investigate the role of prostaglandin E2 (PGE2) on SCAP activation by Escherichia coli lipopolysaccharide (LPS) in vitro. METHODS: SCAP cultures were established and characterized. Increasing concentrations of lipopolysaccharide (0.1-10 µg/mL) were used to investigate cyclooxygenase-2 (COX-2/PTGS2) and PGE2 receptors (EP1-4) gene expression. Then, SCAP were treated with a COX-2 inhibitor (indomethacin) before treatment with different concentrations of LPS. The levels of the chemokine CCL2/monocyte chemoattractant protein 1 and interleukin (IL)-6 were detected in cell supernatants (24 hours) by enzyme-linked immunosorbent assay. Data analysis was performed using analysis of variance followed by the Tukey post test. RESULTS: The expression of COX-2 was up-regulated in the group treated with LPS at 1µg/mL compared with that in the control group. EP1-4 were detected in all experimental conditions at similar levels. SCAP treated with indomethacin presented a down-regulation in the production of LPS-induced CCL2 and the secretion of IL-6. CONCLUSIONS: SCAP showed increased COX-2 (PTGS2) gene expression induced by LPS and a PGE2-dependent production of IL-6 and CCL2.