Adenosine-specific transcriptional programs in murine connective tissue type mast cells

Mast cells are tissue-resident immune cells that are critical for the pathogenesis of allergic and inflammatory disorders. Their physiological functions include host defense against parasites and, more recently, food quality control through antigen avoidance. The purine nucleoside adenosine (ADO), like other mast cell activators, such as antigens or Mrgprb2 agonists, increases intracellular Ca2+ concentration; however, it fails to induce degranulation of preformed mediators when applied to mast cells alone, and there is limited knowledge of whether ADO evokes the de novo synthesis and release of inflammatory mediators in tissue mast cells. An unbiased genome-wide analysis of gene expression triggered by various mast cell activators should enable identification of the gene program specifically activated by ADO in mast cells and thereby reveal new components of the associated inflammatory responses. Here, we performed bulk RNA sequencing in primary murine peritoneal mast cells (PMCs) as connective tissue mast cells. By comparing responses evoked by ADO stimulation with those of the Mrgprb2 agonist compound 48/80 and antigens activating FcεRI receptors, we identified 393 genes uniquely regulated by ADO, including genes encoding the de novo synthesized mediators transforming growth factor α and interleukin 7. Transcription factor activity inference, protein classification, functional enrichment analysis, protein interaction network, and topology analysis revealed a distinct ADO-specific transcriptional gene program involved in phosphoinositide signaling, vesicle trafficking, glycolysis, mitochondrial activity, and cell cycle arrest. The functional relevance of the identified de novo synthesized mediators for ADO-evoked inflammatory reactions can be evaluated in future studies.