Shrestha Annie, Zhu Yi, Ali Aiman
Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada; Department of Dentistry, Mt. Sinai Hospital, Toronto, Toronto, Ontario, Canada.
Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
J Endod. 2024 Apr;50(4):506-513.e2. doi: 10.1016/j.joen.2024.01.015. Epub 2024 Jan 26.
Diet-induced metabolic syndrome may influence the progression and healing of apical periodontitis (AP). The aim of this study was to evaluate the inflammatory immune response of dendritic cells (DCs) and T helper (Th) cells in normal versus obese mice with AP.
Twenty male C57BL/6 mice were divided into 2 groups: normal chow (NC) and high-fat diet (HFD) for 12 wk. AP was induced in both groups by creating pulp exposure of the right first maxillary molar to the oral environment. Contralateral first molars from each mouse were used as a control. The animal's body mass was recorded on a weekly basis, and they were euthanized after 30 d. The maxillae were removed and processed for micro-computed tomography (micro-CT), histologic analysis, and immunofluorescence staining for DCs (CD11c), Th17 (IL-17A), and T regulatory cells (FOXP3 and IL-10). Different groups were analyzed by Mann-Whitney U test, Student t test, and ordinary 1-way analysis of variance followed by Tukey's multiple comparisons test. The level of significance (α) was set at 0.05.
The HFD group showed larger AP lesions than the NC group from micro-CT analysis. For the NC group, induction of AP significantly increased immune cell infiltration when compared with control. HFD showed increased DCs and Th17 infiltration in the control group without AP. In addition, there was no significant change in the amount of DCs and Th17 in the HFD-AP group when compared with the NC-AP and HFD-control groups.
HFD resulted in an increased immune cell infiltration in the periapical area without AP. Despite the larger AP lesion observed in HFD-AP than that of NC-AP, the amount of infiltrated inflammatory cells did not differ significantly. The results of this study suggest that the DCs and Th17 inflammatory pathways are affected by HFD in the periapical region, but their contribution toward AP complicated by metabolic syndrome requires further investigation.
饮食诱导的代谢综合征可能影响根尖周炎（AP）的进展和愈合。本研究的目的是评估正常小鼠与肥胖性AP小鼠中树突状细胞（DCs）和辅助性T细胞（Th）的炎性免疫反应。
将20只雄性C57BL/6小鼠分为2组：正常饮食（NC）组和高脂饮食（HFD）组，持续12周。通过将右侧上颌第一磨牙的牙髓暴露于口腔环境，在两组中诱导AP。将每只小鼠的对侧第一磨牙用作对照。每周记录动物体重，30天后对其实施安乐死。取出上颌骨，进行微计算机断层扫描（micro-CT）、组织学分析以及针对DCs（CD11c）、Th17（IL-17A）和调节性T细胞（FOXP3和IL-10）的免疫荧光染色。采用Mann-Whitney U检验、Student t检验以及普通单因素方差分析，随后进行Tukey多重比较检验对不同组进行分析。显著性水平（α）设定为0.05。
micro-CT分析显示，HFD组的AP病变比NC组更大。对于NC组，与对照组相比，AP的诱导显著增加了免疫细胞浸润。HFD显示在无AP的对照组中DCs和Thl7浸润增加。此外，与NC-AP组和HFD-对照组相比，HFD-AP组中DCs和Th17的数量没有显著变化。
HFD导致无AP时根尖周区域免疫细胞浸润增加。尽管在HFD-AP中观察到的AP病变比NC-AP中的更大，但浸润的炎性细胞数量没有显著差异。本研究结果表明，DCs和Th17炎性途径在根尖周区域受HFD影响，但其对合并代谢综合征的AP的作用需要进一步研究。
