Abstract：
Results of previous studies suggested that programmed cell death 4 (PDCD4) was overexpressed in cerebral ischemia (CI), and mothers against decapentaplegic homolog 1 (SMAD1) is a transcription factor of PDCD4, and it is also elevated in CI; however, the regulatory mechanism of SMAD1/PDCD4 axis in CI remains unclear. The current work has been designed to explore the role and associated mechanisms of SMAD1/PDCD4 in CI. PDCD4 and SMAD1 expressions have been examined by real-time reverse transcription-polymerase chain reaction (RT-qPCR) method, and receiver operating characteristic (ROC) curve analysis has been performed to determine the potential diagnostic value of PDCD4 and SMAD1. An oxygen-glucose deprivation (OGD) model has been used to investigate the effects of PDCD4 and SMAD1 on CI in vitro. Cell apoptosis was evaluated using TdT-mediated dUTP nick end labeling (TUNEL) assays. The interaction between SMAD1 and PDCD4 axis has been confirmed by using dual-luciferase reporter as well as chromatin immunoprecipitation (Ch-IP) assays. Finally, the effects of SMAD1/PDCD4 axis on the ferroptosis of neuron cells have been examined. PDCD4 was overexpressed in blood samples of CI patients. ROC analysis showed the AUC for PDCD4 was 0.7478, and NIHSS and MRS scores were positively correlated with PDCD4 expression. Moreover, the cellular OGD model was established and knockdown of PDCD4 suppressed the apoptosis of neurons. Besides, knockdown of PDCD4 also inhibited ferroptosis of OGD-treated neuron cells in vitro. Additionally, SMAD1 was upregulated in blood samples of CI patients, NIHSS and MRS scores were positively correlated with SMAD1 expression, and SMAD1 is a transcriptional factor of PDCD4, and SMAD1 could transcriptionally regulate the expression of PDCD4. Finally, SMAD1 could regulate the ferroptosis of neuron cells through regulating the transcription of PDCD4. The SMAD1/PDCD4 axis regulates the growth, apoptosis, and ferroptosis of neuron cells, suggesting that targeting the SMAD1/PDCD4 axis may be a potential therapeutic method.
摘要：
以前的研究结果表明，程序性细胞死亡4（PDCD4）在脑缺血（CI）中过度表达，和母亲对十一项截瘫同系物1（SMAD1）是PDCD4的转录因子，并且在CI中也升高；然而，SMAD1/PDCD4轴在CI中的调控机制尚不清楚。目前的工作旨在探索SMAD1/PDCD4inCI的作用和相关机制。PDCD4和SMAD1的表达已通过实时逆转录聚合酶链反应（RT-qPCR）方法检测，并进行了受试者工作特征（ROC）曲线分析，以确定PDCD4和SMAD1的潜在诊断价值。氧葡萄糖剥夺（OGD）模型已用于研究PDCD4和SMAD1对CI的影响。使用TdT介导的dUTP缺口末端标记(TUNEL)测定评价细胞凋亡。SMAD1和PDCD4轴之间的相互作用已通过使用双荧光素酶报告基因以及染色质免疫沉淀（Ch-IP）测定得到证实。最后,已经检查了SMAD1/PDCD4轴对神经元细胞铁性凋亡的影响。PDCD4在CI患者血液样本中过度表达。ROC分析显示PDCD4的AUC为0.7478，NIHSS和MRS评分与PDCD4表达呈正相关。此外，建立细胞OGD模型，PDCD4敲低抑制神经元凋亡。此外,PDCD4的敲低也在体外抑制OGD处理的神经元细胞的铁凋亡。此外,在CI患者的血液样本中SMAD1上调，NIHSS和MRS评分与SMAD1表达呈正相关,SMAD1是PDCD4的转录因子，SMAD1可以转录调节PDCD4的表达。最后,SMAD1可以通过调节PDCD4的转录来调节神经元细胞的铁凋亡。SMAD1/PDCD4轴调节生长，凋亡，和神经元细胞的铁性凋亡，提示靶向SMAD1/PDCD4轴可能是一种潜在的治疗方法。
