Single cell RNAseq analysis of mouse lung after irradiation

Thoracic radiation therapy is limited by the development of acute (i.e. pneumonitis) and late (i.e. pulmonary fibrosis) side-effects. The goal of this study is to analyze, at the single cell level, the molecular impact of two radiation treatments : a conventional/clinical (CONV) modality vs. FLASH, a new radiation method that spares healthy tissue from late radiation-induced toxicities (Science Translational Medicine 6: 245ra293, 2014). We analyzed by single cell RNA sequencing (scRNAseq) dissociated lung cells from a non-irradiated control mouse (NI), a mouse 4 days after CONV thoracic irradiation (CONV) and a mouse 4 days after FLASH irradiation (FLASH). We identify transcriptional alterations induced in the distinct lung cell types after irradiation and show that FLASH irradiated lung cells present a reduced pro-inflammatory phenotype as well as a diminished activation of epithelial lung progenitor cells. In line with previous report (Radiother Oncol 124: 365-9, 2017), this study indicates that FLASH radiation therapy limits inflammation and preserves the regenerative capcity of the lung. Single-cell suspensions were prepared from 10-12 weeks C57Bl/6 mice and single cell RNA-seq libraries were generated using 3' V2 chemistry kit on Chromium Single cell controller (10x Genomics).