[Effect of pioglitazone on periodontitis-related renal injury in mice and its relationship with Klotho].

内容摘要

This study aims to examine the protective effect of the peroxisome proliferator-activated receptor gamma (PPAR-γ) agonist pioglitazone on renal injury linked to periodontitis in mice and to preliminarily explore the relationship between this effect and Klotho. A total of 24 eight-week-old C57 mice were randomly assigned to three groups: control (C), periodontitis (P), and pioglitazone treatment (P+Pio). Silk ligation was employed to induce experimental periodontitis around the maxillary second molars, and pioglitazone was administered through oral gavage. After eight weeks, the mice were euthanized. The maxillae were subjected to Micro-CT scanning. Periodontal and kidney tissues underwent hematoxylin and eosin, periodic acid-Schiff, and Masson's trichrome staining. Renal ultrastructure was observed using transmission electron microscopy (TEM), and malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) were measured. The levels of renal reactive oxygen species (ROS) were assessed through MitoSOX red fluorescence staining. Serum concentrations of creatinine (Cre), blood urea nitrogen (BUN), and albumin (Alb) were evaluated, in addition to urinary protein levels. The gene and protein expression levels of PPAR-γ, Klotho, phosphatidylinositol 3-kinase (PI3K), and serine/threonine kinase (AKT) were determined using quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC). Micro-CT and periodontal histological analysis indicated substantial alveolar bone loss and heightened periodontal pocket depth in the second molar region of the P group relative to the C group. The P+Pio group exhibited reduced effects, compared with the P group. Histological examination of renal tissue and TEM revealed pathological damage in the P group. Pathological damage was alleviated in the P+Pio group. Biochemical assays and MitoSOX staining indicated that the P group demonstrated lower levels of SOD and GSH levels than the C group and increased MDA and ROS levels. Compared with the P group, the P+Pio group exhibited elevated levels of SOD and GSH and reduced levels of MDA and ROS. No notable differences were detected in Cre, BUN, and Alb levels across the groups. qRT-PCR and IHC revealed a reduction in PPAR-γ and Klotho expression levels in the renal tissues and an increase in PI3K and AKT expression levels in the P group compared with the C group. In the P+Pio group, the expression levels of PPAR-γ and Klotho were elevated relative to those of the P group, whereas expression levels of PI3K and AKT were decreased. Pioglitazone can alleviate renal damage associated with periodontitis in mice, and its effect may be related to the upregulation of Klotho expression. 目的: 探究过氧化物酶体增殖物激活受体γ（PPAR-γ）激动剂吡格列酮对小鼠牙周炎相关肾损伤的保护作用，并初步探索该作用与Klotho的关系。方法: 将24只8周龄C57小鼠随机分成3组:对照组（C组）、牙周炎组（P组）、吡格列酮给药组（P+Pio组）。采用丝线结扎构建实验性牙周炎模型，小鼠通过灌胃法给药。8周后对小鼠实施安乐死，上颌骨进行Micro-CT扫描;牙组织及肾组织进行苏木精-伊红、过碘酸雪夫、马松染色;透射电镜（TEM）下观察肾组织超微结构;测定丙二醛（MDA）、超氧化物歧化酶（SOD）、谷胱甘肽（GSH），MitoSOX red荧光染色分析肾组织中活性氧（ROS）水平;收集血清测定肌酐（Cre）、尿素氮（BUN）、白蛋白（Alb），收集尿液测定尿蛋白;进行实时荧光定量聚合酶链反应（qRT-PCR）及免疫组织化学（IHC）测定PPAR-γ、Klotho、磷脂酰肌醇3-激酶（PI3K）、苏氨酸蛋白激酶（AKT）基因及蛋白表达情况。结果: Micro-CT及牙周组织学结果显示，与C组相比，P组第二磨牙区牙槽骨吸收明显，牙周袋加深;P+Pio组比P组第二磨牙区牙槽骨吸收程度减轻，牙周袋变浅。肾脏组织学检查及TEM观察显示，P组肾组织出现病理性损伤;P+Pio组比P组肾组织损伤缓解。生化指标及MitoSOX显示，与C组相比，P组SOD、GSH含量下降，MDA、ROS含量升高;与P组相比，P+Pio组SOD、GSH含量升高，MDA、ROS含量下降;3组间Cre、BUN、Alb差异无统计学意义。qRT-PCR及IHC显示，P组较C组肾组织PPAR-γ、Klotho表达水平降低，PI3K、AKT表达水平升高;P+Pio组较P组肾组织PPAR-γ、Klotho表达水平升高，PI3K、AKT表达水平降低。结论: 吡格列酮可缓解小鼠牙周炎相关肾损伤，其作用可能与上调Klotho表达有关。.