Park Jung-Hwan, Park Sang-Ah, Lee Young-Ju, Joo Na-Rae, Shin Jongdae, Oh Sang-Muk
Department of Biochemistry, College of Medicine, Konyang University, Daejeon 35365, Republic of Korea.
Department of Cell Biology, College of Medicine, Konyang University, Daejeon 35365, Republic of Korea.
Int J Mol Med. 2020 Nov;46(5):1923-1937. doi: 10.3892/ijmm.2020.4712. Epub 2020 Aug 27.
It has been suggested that oxidative stress involving reactive oxygen species (ROS) induces granulosa cell apoptosis, leading to follicular atresia, and that T‑lymphokine‑activated killer cell‑originated protein kinase (TOPK) suppresses cancer cell apoptosis induced by several stimuli. However, it remains to be determined whether TOPK affects oxidative stress‑induced granulosa cell apoptosis. The present study demonstrates that TOPK inhibition increases human granulosa COV434 cell apoptosis induced by hydrogen peroxide (H2O2). Co‑treatment with the TOPK inhibitor, OTS514, in combination with H2O2 increased p53 acetylation and its expression, whereas it decreased Sirtuin 1 (SIRT1) expression, contributing to the promotion of apoptosis. In addition, the SIRT1 activator, resveratrol, or the SIRT1 inhibitor, Ex527, reduced or elevated H2O2‑induced COV434 cell apoptosis, respectively. Furthermore, the p53 inhibitor, Pifithrin‑μ, diminished the augmentation in poly(ADP‑ribose) polymerase (PARP) cleavage induced by OTS514 plus H2O2, while the Mdm2 antagonist, Nutlin 3, increased PARP cleavage. Moreover, OTS514 further decreased the SIRT1 transcriptional activity decreased by H2O2, but promoted the H2O2‑induced p53 or p21 transcriptional activity. Notably, the expression of exogenous p53 reduced SIRT1 transcriptional activity. Taken together, the findings of the present study demonstrate that TOPK inhibition promotes p53‑mediated granulosa cell apoptosis through SIRT1 downregulation in response to H2O2. Therefore, it can be concluded that TOPK suppresses H2O2‑induced apoptosis through the modulation of the p53/SIRT1 axis, suggesting a potential role of TOPK in the regulation of human granulosa cell apoptosis, leading to the promotion of abnormal follicular development.
有人提出，涉及活性氧（ROS）的氧化应激会诱导颗粒细胞凋亡，导致卵泡闭锁，并且T淋巴细胞激活的杀伤细胞起源蛋白激酶（TOPK）可抑制多种刺激诱导的癌细胞凋亡。然而，TOPK是否影响氧化应激诱导的颗粒细胞凋亡仍有待确定。本研究表明，TOPK抑制会增加过氧化氢（H2O2）诱导的人颗粒COV434细胞凋亡。TOPK抑制剂OTS514与H2O2联合处理可增加p53乙酰化及其表达，而降低沉默调节蛋白1（SIRT1）表达，从而促进细胞凋亡。此外，SIRT1激活剂白藜芦醇或SIRT1抑制剂Ex527分别降低或升高了H2O2诱导的COV434细胞凋亡。此外，p53抑制剂Pifithrin‑μ减少了OTS514加H2O2诱导的聚（ADP‑核糖）聚合酶（PARP）裂解增加，而Mdm2拮抗剂Nutlin 3增加了PARP裂解。此外，OTS514进一步降低了H2O2降低的SIRT1转录活性，但促进了H2O2诱导的p53或p21转录活性。值得注意的是，外源性p53的表达降低了SIRT1转录活性。综上所述，本研究结果表明，TOPK抑制通过下调SIRT1促进p53介导的颗粒细胞凋亡以响应H2O2。因此，可以得出结论，TOPK通过调节p53/SIRT1轴抑制H2O2诱导的细胞凋亡，提示TOPK在调节人颗粒细胞凋亡中具有潜在作用，从而促进异常卵泡发育。
