The P2Y6 receptor is distributed on both immune and nonimmune cells and plays an important role in mammalian innate immunity.280 It is preferentially activated by UDP (EC50 = 15 nM).221 Under conditions that cause neuronal damage or in response to LPS, UDP leakage from damaged cells facilitates uptake and removal of cellular debris by activation of the microglial P2Y6 receptors,6,281 especially in PD.221 Indeed, P2X6R is regarded as a potential clinical biomarker of PD and other neuroinflammatory diseases.282
