Zhang Tingting, Mi Jinglin, Qin Xinling, Ouyang Zhechen, Wang Yiru, Li Zhixun, He Siyi, Hu Kai, Wang Rensheng, Huang Weimei
Department of Radiation Oncology, the First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, People's Republic of China.
Guangxi Key Laboratory of Immunology and Metabolism for Liver Diseases, Nanning, Guangxi, People's Republic of China.
J Inflamm Res. 2024 Aug 22;17:5567-5586. doi: 10.2147/JIR.S458794. eCollection 2024.
Radiation-induced pulmonary fibrosis (RIPF) is a common complication after radiotherapy in thoracic cancer patients, and effective treatment methods are lacking. The purpose of this study was to investigate the protective effect of rosmarinic acid (RA) on RIPF in mice as well as the mechanism involved.
m7G-tRNA-seq and tRNA-seq analyses were conducted to identify m7G-modified tRNAs. Western blotting, immunohistochemistry, northwestern blotting, northern blotting, immunofluorescence, wound-healing assays and EdU experiments were performed to explore the molecular mechanism by which RA regulates fibroblast-to-myofibroblast transformation (FMT) by affecting the exosomes of lung epithelial cells. Ribo-seq and mRNA-seq analyses were used to explore the underlying target mRNAs. Seahorse assays and immunoprecipitation were carried out to elucidate the effects of RA on glycolysis and FMT processes via the regulation of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) acetylation.
We found that RA had an antifibrotic effect on the lung tissues of RIPF model mice and inhibited the progression of FMT through exosomes derived from lung epithelial cells. Mechanistically, RA reduced the transcription and translation efficiency of sphingosine kinase 1 in lung fibroblasts by decreasing N7-methylguanosine modification of tRNA, downregulating the expression of tRNAs in irradiated lung epithelial cell-derived exosomes, and inhibiting the interaction between sphingosine kinase 1 and the N-acetyltransferase 10 protein in fibroblasts. Furthermore, the acetylation and cytoplasmic translocation of PFKFB3 were reduced by exosomes derived from irradiated lung epithelial cells, which following RA intervention. This suppression of the FMT process, which is triggered by glycolysis, and ultimately decelerating the progression of RIPF.
These findings suggest that RA is a potential therapeutic agent for RIPF.
放射性肺纤维化（RIPF）是胸段癌患者放疗后常见的并发症，且缺乏有效的治疗方法。本研究旨在探讨迷迭香酸（RA）对小鼠RIPF的保护作用及其相关机制。
进行m7G-tRNA测序和tRNA测序分析以鉴定m7G修饰的tRNA。采用蛋白质免疫印迹法、免疫组织化学法、蛋白质核酸杂交法、Northern印迹法、免疫荧光法、伤口愈合试验和EdU实验，以探究RA通过影响肺上皮细胞外泌体来调节成纤维细胞向肌成纤维细胞转化（FMT）的分子机制。利用核糖体图谱测序和mRNA测序分析来探索潜在的靶mRNA。进行海马实验和免疫沉淀，以阐明RA通过调节6-磷酸果糖-2-激酶/果糖-2,6-二磷酸酶3（PFKFB3）乙酰化对糖酵解和FMT过程的影响。
我们发现RA对RIPF模型小鼠的肺组织具有抗纤维化作用，并通过肺上皮细胞来源的外泌体抑制FMT的进展。机制上，RA通过降低tRNA的N7-甲基鸟苷修饰、下调照射后肺上皮细胞来源外泌体中tRNA的表达以及抑制成纤维细胞中鞘氨醇激酶1与N-乙酰转移酶10蛋白之间的相互作用，降低了肺成纤维细胞中鞘氨醇激酶1的转录和翻译效率。此外，照射后肺上皮细胞来源的外泌体在RA干预后减少了PFKFB3的乙酰化和细胞质转位。这种由糖酵解触发的FMT过程的抑制最终减缓了RIPF的进展。
这些发现表明RA是一种潜在的RIPF治疗药物。
