AIM To investigate the presence, localization and the possible correlation of the fibroblast growth factor receptor-2 (FGFR2) with inflammatory resorption of cementum, periodontal ligament and alveolar bone during development of apical periodontitis in mice. METHODOLOGY Apical periodontitis was experimentally induced in mandibular first molars of mice by pulp exposure to the oral environment. Healthy teeth without pulp exposure were used as controls. At 7, 21 and 42 days following pulp exposure, the animals were euthanized and the jaws were prepared for analysis under conventional and fluorescence microscopy, immunohistochemistry (FGFR2), RT-PCR (RNAm levels of RANK, RANKL, OPG, Runx2 and cathepsin K) and enzyme histochemistry (cementoclasts and osteoclasts). Statistical analysis was performed by Kruskal-Wallis tests and Dunn's post hoc tests for multiple comparisons (α = 0.05) using SAS 9.4 software. RESULTS FGFR2-positive cells were not observed in the tissues surrounding healthy teeth but were observed in teeth with periapical lesions from seven days after root canal contamination. At days 21 and 42 after endodontic infection, the increase in periapical lesion size was accompanied by significantly enhanced expression of FGFR2 (P < 0.0001), significantly increased intensity of inflammatory cells, number of osteoclasts (P < 0.0001) and cementoclasts (P < 0.0001), and significantly enhanced RNAm levels of RANK/RANKL/OPG, Runx2 and cathepsin K compared to day 0 (P < 0.0001). At 21 and 42 days, FGFR2 was also expressed on osteoblasts, fibroblasts and inside enlarged lacunae of cementocytes along with acute and chronic inflammatory cells (macrophages, plasma cells and neutrophils). At all periods and cells, FGFR2 expression was observed in the cell membrane and cytoplasm, but not in the nucleus. CONCLUSION In mice, FGFR2 was not expressed in tissues surrounding healthy teeth but was expressed in apical periodontitis, specifically in the membrane and cytoplasm of osteoblasts, fibroblasts, lacunae of cementocytes, and acute and chronic inflammatory cells (macrophages, plasma cells and neutrophils). Its expression was correlated with the size of the periapical lesions.

中文翻译：

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小鼠根尖周炎中成纤维细胞生长因子受体2的表达。

目的探讨成纤维细胞生长因子受体2（FGFR2）与小鼠尖顶牙周炎发展过程中牙骨质，牙周膜和牙槽骨炎症吸收的关系，定位及其可能的相关性。方法学通过将牙髓暴露于口腔环境，在小鼠的下颌第一磨牙中实验性地诱发了根尖周炎。没有牙髓暴露的健康牙齿用作对照。牙髓接触后第7、21和42天，对动物实施安乐死，并准备下颌进行常规和荧光显微镜，免疫组织化学（FGFR2），RT-PCR（RANK，RANKL，OPG，Runx2和组织蛋白酶K的RNAm水平）分析）和酶组织化学（破骨细胞和破骨细胞）。通过Kruskal-Wallis检验和Dunn's进行统计分析 使用SAS 9.4软件对多个比较进行事后测试（α= 0.05）。结果从健康牙齿周围的组织中未观察到FGFR2阳性细胞，但从根管污染后7天开始在有根尖周病变的牙齿中观察到了FGFR2阳性细胞。牙髓感染后第21天和第42天，根尖周病变大小的增加伴随着FGFR2表达的显着增强（P <0.0001），炎性细胞强度的显着增加，破骨细胞的数量（P <0.0001）和胶质破损（P <0.0001 ），与第0天相比，RANK / RANKL / OPG，Runx2和组织蛋白酶K的RNAm水平显着提高（P <0.0001）。在第21天和第42天，FGFR2还与急性和慢性炎症细胞（巨噬细胞，浆细胞和中性粒细胞）。在所有时期和细胞中，在细胞膜和细胞质中均观察到FGFR2表达，但在细胞核中均未观察到。结论在小鼠中，FGFR2在健康牙齿周围的组织中未表达，但在根尖牙周炎中表达，特别是在成骨细胞，成纤维细胞，胶质细胞腔，急性和慢性炎症细胞（巨噬细胞，浆细胞和嗜中性粒细胞）的膜和细胞质中表达。其表达与根尖周病变的大小相关。成纤维细胞，牙骨质细胞的腔隙以及急慢性炎症细胞（巨噬细胞，浆细胞和中性粒细胞）。其表达与根尖周病变的大小相关。成纤维细胞，牙骨质细胞的腔隙以及急慢性炎症细胞（巨噬细胞，浆细胞和中性粒细胞）。其表达与根尖周病变的大小相关。