IADR Abstract Archives
A20 Functions as a Negative Regulator of Periodontal Inflammation
Objectives: Strategy of targeting endogenous regulators to restrain prolonged inflammatory responses and preserve tissue homeostasis opened a new paradigm in the treatment of chronic conditions. A20 is an ubiquitin-editing enzyme and one of the emergent regulators of inflammation. A20 limits inflammation mainly through interfering with NF-κB signaling pathway which is also considered as one of the key inflammatory pathways in the pathophysiology of periodontitis. We hypothesized that A20 regulates inflammatory response within the oral cavity. The aim of this study was to investigate the function of A20 in periodontal disease using in vivo and ex vivo disease models.
Methods: Bone marrow derived macrophages (BMDMs) from wild type (WT) and A20 deficient transgenic mice (A20+/- and A20-/-) (C57BL/6) were stimulated with Porphyromonas gingivalis (P. gingivalis) (ATCC 33277) up to 12 hours. Inflammatory cytokine levels (IL-6 and TNF) in cell culture supernatants were determined using ELISA. NF-κB activity was assessed measuring IκBα levels in cell extracts using western blot. The effect of A20 in periodontal inflammation was determined in WT and A20 heterozygous mice (A20+/-) using ligature-induced periodontitis model (n=8-10 mice/group) in vivo. A20-/- mouse was excluded from in vivo experiments as they die within 3-4 weeks after birth. Statistical analyses included ANOVA with Tukey multiple comparisons and student t test. P<0.05 was considered significant.
Results: BMDMs from A20 deficient transgenic mice (A20+/- and A20-/-) produced significantly increased IL-6 and TNF upon P. gingivalis stimulation compared to the cells of the WT mice (p<0.001). A20 deficient cells (A20+/- and A20-/-) showed significantly increased IκBα degradation compared to WT cells (p<0.001). In vivo, A20+/- mice displayed significantly increased alveolar loss compared to WT mice (p<0.05).
Conclusions: Our results reveal A20 as a novel regulator of periodontal inflammation and a promising therapeutic target to restore tissue homeostasis in the oral mucosa.
Methods: Bone marrow derived macrophages (BMDMs) from wild type (WT) and A20 deficient transgenic mice (A20+/- and A20-/-) (C57BL/6) were stimulated with Porphyromonas gingivalis (P. gingivalis) (ATCC 33277) up to 12 hours. Inflammatory cytokine levels (IL-6 and TNF) in cell culture supernatants were determined using ELISA. NF-κB activity was assessed measuring IκBα levels in cell extracts using western blot. The effect of A20 in periodontal inflammation was determined in WT and A20 heterozygous mice (A20+/-) using ligature-induced periodontitis model (n=8-10 mice/group) in vivo. A20-/- mouse was excluded from in vivo experiments as they die within 3-4 weeks after birth. Statistical analyses included ANOVA with Tukey multiple comparisons and student t test. P<0.05 was considered significant.
Results: BMDMs from A20 deficient transgenic mice (A20+/- and A20-/-) produced significantly increased IL-6 and TNF upon P. gingivalis stimulation compared to the cells of the WT mice (p<0.001). A20 deficient cells (A20+/- and A20-/-) showed significantly increased IκBα degradation compared to WT cells (p<0.001). In vivo, A20+/- mice displayed significantly increased alveolar loss compared to WT mice (p<0.05).
Conclusions: Our results reveal A20 as a novel regulator of periodontal inflammation and a promising therapeutic target to restore tissue homeostasis in the oral mucosa.