Abstract：
OBJECTIVE: The purpose of this study was to determine whether indoxyl sulfate (IS) is involved in alveolar bone deterioration and to elucidate the mechanism underlying alveolar bone loss in chronic kidney disease (CKD) patients.
METHODS: Mice were divided into the control group, CP group (ligature-induced periodontitis), CKD group (5/6 nephrectomy), and CKD + CP group. The concentration of IS in the gingival crevicular fluid (GCF) was determined by HPLC. The bone microarchitecture was evaluated by micro-CT. MC3T3-E1 cells were stimulated with IS, and changes in mitochondrial morphology and ferroptosis-related factors were detected. RT-PCR, western blotting, alkaline phosphatase activity assays, and alizarin red S staining were utilized to assess how IS affects osteogenic differentiation.
RESULTS: Compared with that in the other groups, alveolar bone destruction in the CKD + CP group was more severe. IS accumulated in the GCF of mice with CKD. IS activated the aryl hydrocarbon receptor (AhR) in vitro, inhibited MC3T3-E1 cell osteogenic differentiation, caused changes in mitochondrial morphology, and activated the SLC7A11/GPX4 signaling pathway. An AhR inhibitor attenuated the aforementioned changes induced by IS.
CONCLUSIONS: IS activated the AhR/SLC7A11/GPX4 signaling pathway, inhibited osteogenesis in MC3T3-E1 cells, and participated in alveolar bone resorption in CKD model mice through ferroptosis.
METHODS: Mice were divided into the control group, CP group (ligature-induced periodontitis), CKD group (5/6 nephrectomy), and CKD + CP group. The concentration of IS in the gingival crevicular fluid (GCF) was determined by HPLC. The bone microarchitecture was evaluated by micro-CT. MC3T3-E1 cells were stimulated with IS, and changes in mitochondrial morphology and ferroptosis-related factors were detected. RT-PCR, western blotting, alkaline phosphatase activity assays, and alizarin red S staining were utilized to assess how IS affects osteogenic differentiation.
RESULTS: Compared with that in the other groups, alveolar bone destruction in the CKD + CP group was more severe. IS accumulated in the GCF of mice with CKD. IS activated the aryl hydrocarbon receptor (AhR) in vitro, inhibited MC3T3-E1 cell osteogenic differentiation, caused changes in mitochondrial morphology, and activated the SLC7A11/GPX4 signaling pathway. An AhR inhibitor attenuated the aforementioned changes induced by IS.
CONCLUSIONS: IS activated the AhR/SLC7A11/GPX4 signaling pathway, inhibited osteogenesis in MC3T3-E1 cells, and participated in alveolar bone resorption in CKD model mice through ferroptosis.
摘要：
目的：本研究的目的是确定硫酸吲哚酚（IS）是否与牙槽骨恶化有关，并阐明慢性肾脏病（CKD）患者牙槽骨丢失的潜在机制。
方法：将小鼠分为对照组，CP组（结扎性牙周炎），CKD组（5/6肾切除术），CKD+CP组。通过HPLC测定龈沟液(GCF)中IS的浓度。通过显微CT评估骨微结构。用IS刺激MC3T3-E1细胞，并检测线粒体形态和铁凋亡相关因子的变化。RT-PCR,西方印迹,碱性磷酸酶活性测定，和茜素红S染色用于评估IS如何影响成骨分化。
结果：与其他组相比，CKD+CP组牙槽骨破坏更严重。在患有CKD的小鼠的GCF中积累。在体外激活芳烃受体（AhR），抑制MC3T3-E1细胞成骨分化，引起线粒体形态的变化，并激活SLC7A11/GPX4信号通路。AhR抑制剂减弱了由IS诱导的上述变化。
结论：IS激活了AhR/SLC7A11/GPX4信号通路，抑制MC3T3-E1细胞成骨，并通过铁性凋亡参与CKD模型小鼠牙槽骨吸收。
方法：将小鼠分为对照组，CP组（结扎性牙周炎），CKD组（5/6肾切除术），CKD+CP组。通过HPLC测定龈沟液(GCF)中IS的浓度。通过显微CT评估骨微结构。用IS刺激MC3T3-E1细胞，并检测线粒体形态和铁凋亡相关因子的变化。RT-PCR,西方印迹,碱性磷酸酶活性测定，和茜素红S染色用于评估IS如何影响成骨分化。
结果：与其他组相比，CKD+CP组牙槽骨破坏更严重。在患有CKD的小鼠的GCF中积累。在体外激活芳烃受体（AhR），抑制MC3T3-E1细胞成骨分化，引起线粒体形态的变化，并激活SLC7A11/GPX4信号通路。AhR抑制剂减弱了由IS诱导的上述变化。
结论：IS激活了AhR/SLC7A11/GPX4信号通路，抑制MC3T3-E1细胞成骨，并通过铁性凋亡参与CKD模型小鼠牙槽骨吸收。
