Transcriptome analysis of mild hypothermia protection against radiation-induced rat lung injury based on RNA-seq

To analyze the differentially expressed genes (DEGs) with radiation-induced rat lung injury, and to reveal the protective mechanism for mild hypothermia in the radiation-induced lung injury in rats at the transcriptome level.

A total of 10 male SD rats aged 6-8 weeks were randomly divided into 2 groups to establish a rat model of radiation-induced lung injury, and one group was treated with mild hypothermia. RNA was extracted from left lung tissue of each group, and sequenced by BGISEQ-500 platform. Significance analysis of DEGs was carried out by edgeR software. Gene ontology (GO) function enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were used to analyze the gene function. Then 5 key DEGs were verified by real-time reverse transcription PCR (real-time RT-PCR).

There were 2 790 DEGs (false discovery rate<0.001, |log₂(fold change)|>1) in the mild hypothermia group compared with the model group, in which 2 257 genes were up-regulated and 533 genes were down-regulated. When real-time RT-PCR was used to validate the 5 key genes, the result was consistent with the RNA-seq. GO functional enrichment analysis showed that these DEGs were related to cell binding, metabolic process and cell membrane structure, etc. KEGG pathway enrichment analysis showed that these genes were involved in important biological pathways such as cell adhesion molecules, mammalian target of rapamycin, tight junction, and NF-κB.

The DEGs and pathways related to mild hypothermia protection against radiation-induced lung injury in rats are obtained, which provides an experimental basis for the protection of mild hypothermia against radiation-induced lung injury.