Temporal expression of P2X7 purinergic receptor during the course of experimental autoimmune encephalomyelitis.

Purinergic P2X(7) receptors are nucleotide-gated ion channels widely distributed in brain. Strong evidence suggests that they are involved in cross-talk between glial and neuronal cells. These receptors activated under pathological conditions may participate in regulation of inflammatory response and cell death. In this study we show the expression of P2X(7) protein and mRNA during the course of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), in different stages of the disease (4, 6, 8, 10 post-immunization). The enhanced expression of the receptor at the level of both mRNA and protein was observed in the peak of neurological symptoms and was connected mostly with neurons. However, early overexpression of receptor protein was observed also in an asymptomatic phase of EAE and was tightly related to astrocytic pool of cells. This suggests the early involvement of this kind of receptor into pathological mechanisms leading for symptoms characteristic for EAE.