Transcriptomic-based roadmap to the healthy and ozone-exposed lung

The lung is constantly exposed to a myriad of exogenous stressors. Ground-level ozone represents a ubiquitous and extremely reactive anthropogenic toxicant, impacting the health of millions across the globe. While abundant, epidemiological, in vivo, and in vitro data focuses the ozone toxicity in individual cell types (e.g. epithelial type II, alveolar macrophages) or signaling pathways involved in the injury (e.g. akt, glutathione). When appropriately used, bulk and single-cell RNA sequencing techniques have the potential to provide complete, and in certain cases unbiased, information of the molecular events taking place in the steady-state and injured lung, and even capture the phenotypic diversity of neighboring cells. To this end, this review compiles information pertaining to the latest understanding of lung cell identity and activation in the steady-state and ozone-exposed lung. In addition, it discusses the value and benefits of multi-omics approaches and other tools developed to predict cell–cell communication and dissect spatial heterogeneity.