Differential response of Drosophila cell lines to extracellular adenosine

Adenosine (Ado) is a crucial metabolite that affects a wide range of physiological processes. Key proteins regulating Ado signaling, transport and metabolism are conserved among vertebrates and invertebrates. It is well known that Ado influences proliferation of several vertebrate and invertebrate cells. Here we show that Ado negatively influences viability, changes morphology and mitochondrial polarity of the Drosophila imaginal disc cell line (Cl.8+) via a mechanism exclusively dependent on cellular Ado uptake. High transport of Ado is followed by phosphorylation and ATP production as a part of Ado salvation, which at higher concentrations may interfere with cellular homeostasis. In contrast, hematopoietic cell line Mbn2, which grows well in high Ado concentration, preferentially uses adenosine deaminase as a part of the purine catabolic pathway. Our results show that different types of Drosophila cell lines use different pathways for Ado conversion and suggest that such differences may be an important part of complex mechanisms maintaining energy homeostasis in the body.

Figure optionsDownload high-quality image (170 K)Download as PowerPoint slideHighlights
► Adenosine growth inhibitory effect in Cl.8+ cells depends on its uptake via both equilibrative and concentrative transporters.
► Imaginal disc Cl.8+ cells take up large amounts of adenosine, which is then phosphorylated and used for ATP production.
► In contrast, hematopoietic Mbn2 cells preferentially use adenosine deaminase as a part of the purine catabolic pathway.
► Using high levels of extracellular adenosine for ATP synthesis in C18+ cells may have deleterious effects.
► Different cell types use different pathways for adenosine conversion as a part of energy homeostasis maintaining mechanisms.