Guo Huan, Zhao Xinke, Su Haixiang, Ma Chengxu, Liu Kai, Kong Shanshan, Liu Kedan, Li Haining, Chang Juan, Wang Tao, Guo Hongyun, Wei Huiping, Fu Zhaoyuan, Lv Xinfang, Li Yingdong
School of Basic Medical Sciences, Lan Zhou University, Lan Zhou, Gan Su, China.
Gansu University of Chinese Medicine, Lan Zhou, Gan Su, China.
PeerJ. 2020 Dec 10;8:e10502. doi: 10.7717/peerj.10502. eCollection 2020.
Radiation exposure of the thorax is associated with a greatly increased risk of cardiac morbidity and mortality even after several decades of advancement in the field. Although many studies have demonstrated the damaging influence of ionizing radiation on cardiac fibroblast (CF) structure and function, myocardial fibrosis, the molecular mechanism behind this damage is not well understood. miR-21, a small microRNA, promotes the activation of CFs, leading to cardiac fibrosis. miR-21 is overexpressed after irradiation; however, the relationship between increased miR-21 and myocardial fibrosis after irradiation is unclear. This study was conducted to investigate gene expression after radiation-induced CF damage and the role of miR-21 in this process in rats.
We sequenced irradiated rat CFs and performed weighted correlation network analysis (WGCNA) combined with differentially expressed gene (DEG) analysis to observe the effect on the expression profile of CF genes after radiation.
DEG analysis showed that the degree of gene changes increased with the radiation dose. WGCNA revealed three module eigengenes (MEs) associated with 8.5-Gy-radiation-the Yellow, Brown, Blue modules. The three module eigengenes were related to apoptosis, G2/M phase, and cell death and S phase, respectively. By blocking with the cardiac fibrosis miRNA miR-21, we found that miR-21 was associated with G2/M blockade in the cell cycle and was mainly involved in regulating extracellular matrix-related genes, including , , , , and . Stem-loop quantitative real-time PCR was performed to verify the expression of these genes. Five genes showed higher expression after 8.5 Gy-radiation in CFs. The target genes of miR-21 predicted online were and , which showed much higher expression after treatment with antagomir-miR-21 in 8.5-Gy-irradiated CFs. Thus, miR-21 may play the role of fibrosis and G2/M blockade in regulating , , , , , and post-irradiation.
即使在该领域取得了几十年的进展之后，胸部辐射暴露仍与心脏发病和死亡风险大幅增加相关。尽管许多研究已经证明电离辐射对心脏成纤维细胞（CF）结构和功能、心肌纤维化有损害作用，但这种损害背后的分子机制尚不清楚。微小RNA-21（miR-21）可促进CFs的激活，导致心脏纤维化。照射后miR-21表达上调；然而，照射后miR-21表达增加与心肌纤维化之间的关系尚不清楚。本研究旨在探讨辐射诱导的CF损伤后的基因表达以及miR-21在大鼠这一过程中的作用。
我们对照射后的大鼠CFs进行测序，并结合差异表达基因（DEG）分析进行加权基因共表达网络分析（WGCNA），以观察辐射后对CF基因表达谱的影响。
DEG分析表明，基因变化程度随辐射剂量增加而增加。WGCNA揭示了与8.5 Gy辐射相关的三个模块特征基因（MEs）——黄色、棕色、蓝色模块。这三个模块特征基因分别与细胞凋亡、G2/M期以及细胞死亡和S期相关。通过用心脏纤维化微小RNA miR-21进行阻断，我们发现miR-21与细胞周期中的G2/M期阻滞相关，并且主要参与调节细胞外基质相关基因，包括[此处原文缺失相关基因名称]。进行茎环定量实时PCR以验证这些基因的表达。五个基因在CFs接受8.5 Gy辐射后表达更高。在线预测的miR-21靶基因是[此处原文缺失相关基因名称]，在用抗miR-21处理的8.5 Gy照射的CFs中，它们的表达明显更高。因此，miR-21可能在照射后调节[此处原文缺失相关基因名称]时发挥纤维化和G2/M期阻滞的作用。
