[Non-targeted Metabolomics-based Exploration of Radiation-induced Metabolic Alterations in Mouse Lung Epithelial Cells].

Background: Metabolic change is one of the important characteristics of radiation pneumonitis. Radiotherapy, as a conventional method for the treatment of thoracic tumors, can not only effectively kill tumor cells, but also cause adverse reactions such as local inflammation and fibrosis, which leads to limited therapeutic effect and profound impact on the quality of life of patients. Therefore, it is of great significance to explore the metabolic changes caused by radiotherapy. The aim of this study was to investigate the effects of X-ray irradiation on the metabolism of a mouse lung epithelial cell line (murine lung epithelial-12, MLE12).

Methods: MLE12 cells were' cultured in vitro and randomly divided into radiation group (IR) and control group (NC). Cells in the IR group were irradiated at a dose of 10 Gy using a Hitachi X-ray irradiator. Cell supernatant samples were collected at 48 h after irradiation. Metabolomic analysis of the samples was performed by liquid chromatograph mass spectrometer (LC/MS).

Results: LC/MS metabolomics analysis revealed the metabolic changes of MLE12 cells at 48 h after irradiation. A total of 38 secretory metabolites were altered in the IR group compared with the NC group. According to the annotation of Kyoto Encyclopedia of Genes and Genomes (KEGG) database, the differential metabolites are mainly involved in nucleotide metabolism, amino acid metabolism and lipid metabolism, among which the difference in nucleotide metabolism is the most significant.

Conclusions: The metabolism of MLE12 cells was significantly affected by X-ray irradiation, mainly affecting the nucleotide metabolic pathways, including purine and pyrimidine metabolites and related metabolic pathways.