Abstract：
BACKGROUND: Oral leukoplakia (OLK) is the most common oral potentially malignant disorder (OPMD), which can be malignantly transformed into oral squamous cell carcinoma (OSCC). Peroxiredoxin1(Prx1) has been predicted to bind to Prohibitin2 (PHB2), which confers to affect OLK progression; however, the mechanism of Prx1/PHB2 mediated mitophagy involved in OLK remains unclear.
METHODS: This study aimed to explore the mechanism of the Prx1/PHB2 axis on senescence in OLK through mediating mitophagy. The positive rate of Ki67 and the expression of p21, p16, PHB2, and LC3 in human normal, OLK, and OSCC tissues were detected by immunohistochemical staining. The mitophagy and mitochondrial function changes were then analyzed in Prx1 knockdown and Prx1C52S mutations in dysplastic oral keratinocyte (DOK) cells treated with H2O2. In situ Proximity Ligation Assay combined with co-immunoprecipitation was used to detect the interaction between Prx1 and PHB2.
RESULTS: Clinically, the positive rate of Ki67 progressively increased from normal to OLK, OLK with dysplasia, and OSCC. Higher p21, p16, PHB2, and LC3 expression levels were observed in OLK with dysplasia than in normal and OSCC tissues. In vitro, PHB2 and LC3II expression gradually increased with the degree of DOK cell senescence. Prx1/PHB2 regulated mitophagy and affected senescence in H2O2-induced DOK cells. Furthermore, Prx1C52S mutation specifically reduced interaction between Prx1 and PHB2. Prx1Cys52 is associated with mitochondrial reactive oxygen species (ROS) accumulated and cell cycle arrest.
CONCLUSIONS: Prx1Cys52 functions as a redox sensor that binds to PHB2 and regulates mitophagy in the senescence of OLK, suggesting its potential as a clinical target.
METHODS: This study aimed to explore the mechanism of the Prx1/PHB2 axis on senescence in OLK through mediating mitophagy. The positive rate of Ki67 and the expression of p21, p16, PHB2, and LC3 in human normal, OLK, and OSCC tissues were detected by immunohistochemical staining. The mitophagy and mitochondrial function changes were then analyzed in Prx1 knockdown and Prx1C52S mutations in dysplastic oral keratinocyte (DOK) cells treated with H2O2. In situ Proximity Ligation Assay combined with co-immunoprecipitation was used to detect the interaction between Prx1 and PHB2.
RESULTS: Clinically, the positive rate of Ki67 progressively increased from normal to OLK, OLK with dysplasia, and OSCC. Higher p21, p16, PHB2, and LC3 expression levels were observed in OLK with dysplasia than in normal and OSCC tissues. In vitro, PHB2 and LC3II expression gradually increased with the degree of DOK cell senescence. Prx1/PHB2 regulated mitophagy and affected senescence in H2O2-induced DOK cells. Furthermore, Prx1C52S mutation specifically reduced interaction between Prx1 and PHB2. Prx1Cys52 is associated with mitochondrial reactive oxygen species (ROS) accumulated and cell cycle arrest.
CONCLUSIONS: Prx1Cys52 functions as a redox sensor that binds to PHB2 and regulates mitophagy in the senescence of OLK, suggesting its potential as a clinical target.
摘要：
背景：口腔白斑（OLK）是最常见的口腔潜在恶性疾病（OPMD），可恶性转化为口腔鳞状细胞癌（OSCC）。Peroxiredoxin1（Prx1）已被预测与Prohibitin2（PHB2）结合，这会影响OLK的进展；然而，Prx1/PHB2介导的线粒体自噬参与OLK的机制尚不清楚。
方法：本研究旨在探讨Prx1/PHB2轴通过介导线粒体自噬影响OLK衰老的机制。Ki67的阳性率及p21、p16、PHB2、LC3在人正常人中的表达，OLK,免疫组化染色检测OSCC组织。然后在用H2O2处理的发育不良的口腔角质形成细胞（DOK）细胞中的Prx1敲低和Prx1C52S突变中分析线粒体自噬和线粒体功能变化。结合免疫共沉淀的原位邻近连接测定用于检测Prx1和PHB2之间的相互作用。
结果：临床，Ki67的阳性率从正常到OLK逐渐增加，OLK患有发育不良，OSCC。在发育异常的OLK中观察到的p21，p16，PHB2和LC3表达水平高于正常和OSCC组织。体外，PHB2和LC3II表达随DOK细胞衰老程度逐步增高。在H2O2诱导的DOK细胞中，Prx1/PHB2调节线粒体自噬并影响衰老。此外，Prx1C52S突变特异性降低了Prx1和PHB2之间的相互作用。Prx1Cys52与线粒体活性氧（ROS）积累和细胞周期停滞有关。
结论：Prx1Cys52作为氧化还原传感器，与PHB2结合并调节OLK衰老过程中的线粒体自噬，表明其作为临床目标的潜力。
方法：本研究旨在探讨Prx1/PHB2轴通过介导线粒体自噬影响OLK衰老的机制。Ki67的阳性率及p21、p16、PHB2、LC3在人正常人中的表达，OLK,免疫组化染色检测OSCC组织。然后在用H2O2处理的发育不良的口腔角质形成细胞（DOK）细胞中的Prx1敲低和Prx1C52S突变中分析线粒体自噬和线粒体功能变化。结合免疫共沉淀的原位邻近连接测定用于检测Prx1和PHB2之间的相互作用。
结果：临床，Ki67的阳性率从正常到OLK逐渐增加，OLK患有发育不良，OSCC。在发育异常的OLK中观察到的p21，p16，PHB2和LC3表达水平高于正常和OSCC组织。体外，PHB2和LC3II表达随DOK细胞衰老程度逐步增高。在H2O2诱导的DOK细胞中，Prx1/PHB2调节线粒体自噬并影响衰老。此外，Prx1C52S突变特异性降低了Prx1和PHB2之间的相互作用。Prx1Cys52与线粒体活性氧（ROS）积累和细胞周期停滞有关。
结论：Prx1Cys52作为氧化还原传感器，与PHB2结合并调节OLK衰老过程中的线粒体自噬，表明其作为临床目标的潜力。
