Nanjing University of Chinese Medicine, Nanjing, 210000, China.
Department of Reproductive Medicine, Affiliated Hospital of Nanjing University of Nanjing University of Chinese Medicine, Nanjing, 210000, China.
Biochem Biophys Res Commun. 2023 Oct 15;677:54-62. doi: 10.1016/j.bbrc.2023.08.004. Epub 2023 Aug 2.
Polycystic ovary syndrome (PCOS) exhibits the highest morbidity among endocrine diseases in women ranging from age 18 to 44. However, its pathogenesis remains unclear. The imbalance between systemic and ovarian oxidative stress (OS) is a key characteristic of PCOS, and accumulating evidence indicates that the antioxidative protein nuclear factor erythroid-2-related factor 2 (Nrf2) is implicated in cell apoptosis and inflammation caused by OS. The activated kinase 2 (PAK2)/-catenin/c-Myc/pyruvate kinase M2 (PKM2) axis is a newly identified signaling pathway that may regulate Nrf2 expression and thereby influence OS. In this study, we sought to identify PAK2 expression and function in PCOS cells. PAK2 and downstream PKM2 expression in KGN cells and tissues were detected by microarray and qPCR. Cell viability was determined using CCK-8 and colony formation assays (CFAs). Apoptosis was examined by flow cytometry. qPCR and ELISA were used to examine cell inflammation. Oxidant and OS-related enzymes were examined by ELISA. We found that PAK2 and PKM2 expression levels were reduced in KGN cells and PCOS ovarian cortex tissues. PAK2 overexpression activated β-catenin/c-Myc/PKM2 while PAK2 silencing deactivated it. PAK2 overexpression was reduced, whereas PAK2 silencing promoted, KGN cell proliferation and colony formation. Cell apoptosis and inflammation were also induced by PAK2 overexpression but were alleviated by its silencing. Furthermore, increased peroxidation product levels decreased antioxidative protein activities, and deactivated antioxidative Nrf2/HO-1 pathway were detected in PAK2-overexpressing KGN cells, whereas these effects were counteracted in PAK2 silenced cells. Our data suggest that PAK2 and its associated β-catenin/c-Myc/PKM2 inhibited cell viability and induced apoptosis and inflammation by triggering OS by deactivating the Nrf2/HO-1 pathway, suggesting the potential of PAK2 as a therapeutic PCOS treatment target.
多囊卵巢综合征（PCOS）是 18-44 岁女性内分泌疾病中发病率最高的疾病。然而，其发病机制尚不清楚。全身和卵巢氧化应激（OS）失衡是 PCOS 的一个重要特征，越来越多的证据表明抗氧化蛋白核因子红细胞 2 相关因子 2（Nrf2）参与 OS 引起的细胞凋亡和炎症。新发现的激活激酶 2（PAK2）/-连环蛋白/c-Myc/丙酮酸激酶 M2（PKM2）轴可能是一种新的信号通路，调节 Nrf2 的表达，从而影响 OS。在这项研究中，我们试图确定 PAK2 在 PCOS 细胞中的表达和功能。通过微阵列和 qPCR 检测 KGN 细胞和组织中 PAK2 和下游 PKM2 的表达。使用 CCK-8 和集落形成实验（CFAs）测定细胞活力。通过流式细胞术检查细胞凋亡。qPCR 和 ELISA 用于检测细胞炎症。通过 ELISA 检测氧化应激和 OS 相关酶。我们发现 PAK2 和 PKM2 的表达水平在 KGN 细胞和 PCOS 卵巢皮质组织中降低。PAK2 过表达激活 β-连环蛋白/c-Myc/PKM2，而 PAK2 沉默则使其失活。PAK2 过表达减少，而 PAK2 沉默促进 KGN 细胞增殖和集落形成。细胞凋亡和炎症也被 PAK2 过表达诱导，但被其沉默缓解。此外，在 PAK2 过表达的 KGN 细胞中检测到过氧化产物水平升高，抗氧化蛋白活性降低，抗氧化 Nrf2/HO-1 通路失活，而在 PAK2 沉默的细胞中则出现相反的情况。我们的数据表明，PAK2 及其相关的 β-连环蛋白/c-Myc/PKM2 通过激活 OS 抑制细胞活力并诱导细胞凋亡和炎症，从而通过失活 Nrf2/HO-1 通路发挥作用，这表明 PAK2 作为 PCOS 治疗靶点的潜力。
