Iron accumulation is associated with periodontal destruction in a mouse model of HFE-related haemochromatosis

Objective: To investigate the effect of Hfe gene mutation on the distribution of iron and periodontal bone loss in periodontal tissues. Background data: It remains unclear how tissue iron loading affects the periodontium architectures in a genetic animal model of hereditary haemochromatosis (HH). Methods: Male C57BL/6 Hfe^−/− (8 weeks old) and wild-type (WT) mice were utilized to examine the iron distribution in periodontal tissues, as well as periodontal tissues changes using micro-computed tomography and histomorphometric analysis. Furthermore, tissue inflammatory mediators, bone markers and periodontal pathogens were carried out in PFA-fixed paraffin-embedded tissues using ELISA, RT-qPCR and genomic DNA qPCR, respectively. Results: Excessive iron deposition was found in the periodontal ligament, gingiva and alveolar bone in Hfe^−/− mice relative to their WT counterparts. This, in turn, was associated with significant periodontal bone loss, increased cemento-enamel junction-alveolar bone crest distance and decreased expression of molecules involved in bone development and turnover. Furthermore, the pro-inflammatory cytokine - interleukin 6 and periodontal bacteria – Campylobacter rectus were significantly increased in Hfe^−/− mice compared with WT controls. Conclusion: Our results suggest that the iron loading in a mouse model of HH decreases alveolar bone formation and leads to alterations in the inflammatory state in the periodontium. Periodontal health should be assessed during the clinical assessment of HFE-HH patients.