南方医科大学学报 ›› 2023, Vol. 43 ›› Issue (4): 568-576.doi: 10.12122/j.issn.1673-4254.2023.04.09

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Akt2抑制剂促进大鼠根尖周炎症微环境中巨噬细胞的极化:基于降低miR-155-5p的表达

李敬怡,杨思圆,韩 振,江天乐,朱 耀,周子航,周静萍   

  1. 皖南医学院口腔医学院//皖南医学院口腔疾病研究中心,安徽 芜湖 241000
  • 出版日期:2023-04-20 发布日期:2023-05-16

Akt2 inhibitor promotes M2 macrophage polarization in rats with periapical inflammation by reducing miR-155-5p expression

LI jingyi, YANG Siyuan, HAN Zhen, JIANG Tianle, ZHU Yao, ZHOU Zihang, ZHOU Jingping   

  1. School of Stomatology/ Oral Disease Research Center, Wannan Medical College, Wuhu 241000, China
  • Online:2023-04-20 Published:2023-05-16

摘要: 目的 通过构建大鼠慢性根尖周炎模型,探讨Akt2抑制剂对根尖周组织巨噬细胞极化的影响及其相关因素。方法 随机选取32 只健康SD大鼠,其中28只作为实验组,通过髓腔开放法建立大鼠根尖周炎模型,在模型构建过程中分别在下颌第一磨牙左右侧髓腔内注射生理盐水和Akt2抑制剂。另外4只为健康对照组,不做任何处理。于开髓后第7、14、21、28天随机处死7只实验组和1只健康对照组大鼠后,分离下颌骨获取样本。X线和苏木精-伊红(HE)染色观察根尖周组织炎症浸润情况;免疫组织化学(IHC)染色观察Akt2、巨噬细胞及炎症介质的表达与定位,逆转录-聚合酶链反应(RT-PCR)观察Akt2、CD86、CD163、炎症介质(IL-6、IL-10)、miR-155-5p及C/EBPβ的mRNA表达,分析对巨噬细胞极化的影响。结果 X线和苏木精-伊红染色结果显示:髓腔开放21 d后大鼠根尖周表现明显的慢性炎症,确认慢性大鼠根尖周炎模型构建成功。IHC染色和RT-PCR结果表明:与健康对照组相比,髓腔开放21 d后实验组大鼠根尖周炎组织中Akt2、CD86、CD163、miR-155-5p、C/EBPβ、及IL-10表达显著增高(P<0.05),与生理盐水组相比,Akt2抑制剂组大鼠根尖周组织中Akt2、CD86、miR-155-5p和IL-6的表达水平以及CD86+M1型/CD163+M2型巨噬细胞比值显著降低(P<0.05),而CD163、C/EBPβ和IL-10的表达水平明显增高(P<0.05)。结论 抑制Akt2可减缓大鼠根尖周炎症进展,促进大鼠根尖周炎症微环境中巨噬细胞向M2型极化;Akt2抑制剂可能通过降低miR-155-5p表达,激活Akt信号通路中转录因子C/EBPβ的表达,从而影响巨噬细胞极化。

关键词: 根尖周炎;Akt2;巨噬细胞极化;miR-155-5p;C/EBPβ

Abstract: Objective To investigate the effect of Akt2 inhibitor on macrophage polarization in the periapical tissue in a rat model of periapical inflammation. Methods Rat models of periapical inflammation were established in 28 normal SD rats by opening the pulp cavity of the mandibular first molars, followed by injection of normal saline and Akt2 inhibitor into the left and right medullary cavities, respectively. Four rats without any treatment served as the healthy control group. At 7, 14, 21 and 28 days after modeling, 7 rat models and 1 control rat were randomly selected for observation of inflammatory infiltration in the periapical tissues by X-ray and HE staining. Immunohistochemistry was used to detect the expression and localization of Akt2, macrophages and the inflammatory mediators. RT-PCR was performed to detect the mRNA expressions of Akt2, CD86, CD163, inflammatory mediators, miR-155-5p and C/EBPβ to analyze the changes in macrophage polarization. Results X-ray and HE staining showed that periapical inflammation was the most obvious at 21 days after modeling in the rats. Immunohistochemistry and RT-PCR showed that compared with those in the control rats, the expressions of Akt2, CD86, CD163, miR-155-5p, C/EBPβ, and IL-10 increased significantly in the rat models at 21 days (P<0.05). Compared with saline treatment, treatment with the Akt2 inhibitor significantly decreased the expression levels of Akt2, CD86, miR-155-5p and IL-6 and the ratio of CD86+M1/CD163+M2 macrophages (P<0.05) and increased the expression levels of CD163, C/EBPβ and IL-10 in the rat models (P<0.05). Conclusion Inhibition of Akt2 can delay the progression of periapical inflammation in rats and promote M2 macrophage polarization in the periapical inflammatory microenvironment possibly by reducing miR-155-5p expression and activating the expression of C/EBPβ in the Akt signaling pathway.

Key words: periapical inflammation; Akt2; macrophage polarization; miR-155-5p; C/EBPβ