Extracellular adenosine triphosphate and adenosine diphosphate (ATP and ADP)

Extracellular adenosine triphosphate (ATP) and adenosine diphosphate (ADP) are essential signaling molecules that operate within the purinergic signaling framework to regulate diverse physiological and pathological processes. While ATP is primarily recognized as an intracellular energy source, its release into the extracellular space—often as a result of cell stress, injury, or controlled secretion—allows it to function as a potent damage-associated molecular pattern (DAMP) that triggers pro-inflammatory responses through P2X and P2Y receptors [1][2]. ADP, the immediate breakdown product of ATP, is a critical mediator of platelet aggregation and vascular tone, primarily acting through the P2Y1 and P2Y12 receptors [3]. In the tumor microenvironment, high concentrations of extracellular ATP can be converted into immunosuppressive adenosine by the ectonucleotidases CD39 and CD73, a process that tumors exploit to evade the immune system [2][4]. Therapeutic strategies targeting this pathway include the use of P2Y12 receptor antagonists for cardiovascular diseases and the development of inhibitors against CD39 or CD73 to restore anti-tumor immunity in oncology [5][6]. Consequently, extracellular ATP and ADP are central to the "ATP-adenosine axis," representing a significant area of focus for drug development in inflammation, hematology, and immuno-oncology.

Other names

Purinergic ligandseATPeADPExtracellular nucleotidesPurinergic signaling molecules

Modulation of purinergic signaling through the antagonism of P2X and P2Y receptors or the inhibition of ectonucleotidases like CD39 and CD73.