Longitudinal Single-Cell Transcriptomics Reveals a Role for Serpina3n-Mediated Resolution of Inflammation in a Mouse Colitis Model

BACKGROUND & AIMS: Proper resolution of inflammation is essential to maintaining homeostasis, which is important as a dysregulated inflammatory response has adverse consequences, even being regarded as a hallmark of cancer. However, our picture of dynamic changes during inflammation remains far from comprehensive. METHODS: Here we used single-cell transcriptomics to elucidate changes in distinct cell types and their interactions in a mouse model of chemically induced colitis. RESULTS: Our analysis highlights the stromal cell population of the colon functions as a hub with dynamically changing roles over time. Importantly, we found that Serpina3n, a serine protease inhibitor, is specifically expressed in stromal cell clusters as inflammation resolves, interacting with a potential target, elastase. Indeed, genetic ablation of the Serpina3n gene delays resolution of induced inflammation. Furthermore, systemic Serpina3n administration promoted the resolution of inflammation, ameliorating colitis symptoms. CONCLUSIONS: This study provides a comprehensive, single-cell understanding of cell-cell interactions during colorectal inflammation and reveals a potential therapeutic target that leverages inflammation resolution.