Bulk RNA-sequencing of normal and Gls1 KO alveolar epithelial cells in mouse

Effective alveolar repair depends on the differentiation of type 2 alveolar epithelial cells (AT2), the resident lung stem/progenitor cells, into type 1 alveolar epithelial cells (AT1) to restore gas exchange surfaces. Here, we reveal that glutaminolysis mediated by glutaminase 1 (GLS1) orchestrates a metabolic checkpoint essential for AT2 stem/progenitor cell differentiation.

Using primary AT2 cells, alveolar organoids, and lineage-tracing mouse models, we demonstrate that GLS1 expression is upregulated during AT2-to-AT1 differentiation and is essential for this process. The differentiation program is accompanied by metabolic reprogramming characterized by increased glycolysis and enhanced glutamine flux into the TCA cycle. AT2-specific GLS1 deletion severely impairs differentiation both in vitro and in vivo, leading to defective alveolar repair and exacerbated pulmonary fibrosis following bleomycin injury.