Departments of Medicine and Biochemistry, Whitaker Cardiovascular Institute, and Evans Center for Interdisciplinary Biomedical Research, Boston University School of Medicine, CVI, 700 Albany St., Boston, MA, 02118, USA.
Purinergic Signal. 2011 Sep;7(3):357-65. doi: 10.1007/s11302-011-9220-4. Epub 2011 Feb 8.
Adenosine is an important regulatory metabolite and an inhibitor of platelet activation. Adenosine released from different cells or generated through the activity of cell-surface ectoenzymes exerts its effects through the binding of four different G-protein-coupled adenosine receptors. In platelets, binding of A(2) subtypes (A(2A) or A(2B)) leads to consequent elevation of intracellular cyclic adenosine monophosphate, an inhibitor of platelet activation. The significance of this ligand and its receptors for platelet activation is addressed in this review, including how adenosine metabolism and its A(2) subtype receptors impact the expression and activity of adenosine diphosphate receptors. The expression of A(2) adenosine receptors is induced by conditions such as oxidative stress, a hallmark of aging. The effect of adenosine receptors on platelet activation during aging is also discussed, as well as potential therapeutic applications.
腺苷是一种重要的调节代谢物和血小板激活抑制剂。不同细胞释放的腺苷或通过细胞表面ectoenzymes 的活性产生的腺苷，通过结合四种不同的 G 蛋白偶联腺苷受体发挥其作用。在血小板中，A(2)亚型（A(2A)或 A(2B)）的结合导致细胞内环磷酸腺苷的浓度升高，从而抑制血小板的激活。本综述讨论了这种配体及其受体对血小板激活的意义，包括腺苷代谢及其 A(2)亚型受体如何影响二磷酸腺苷受体的表达和活性。A(2)腺苷受体的表达是由氧化应激等衰老特征的条件诱导的。本文还讨论了在衰老过程中腺苷受体对血小板激活的影响，以及潜在的治疗应用。
