Possible protective role of the 489C>T P2X7R polymorphism in Alzheimer's disease.

Inflammation is a key factor in the onset and progression of Alzheimer's disease (AD). The P2X7 receptor (P2X7R) is increasingly recognized as key pro-inflammatory receptor. A recent study has shown that activation of microglia by amyloid β (Aβ) and associated release of IL-1β, requires P2X7R expression. In this study we assessed by RT-PCR in genomic DNA samples, the frequency of two single-nucleotide polymorphisms (SNP) of P2X7R in AD patients compared to age-matched non demented elderly. Our data show that the 489C>T SNP was significantly less frequent in AD patients than in controls (p=0.01), whereas there was no statistical difference in 1513A>C frequency in either groups. In addition, presence of the 1513C allele and absence of the 489C allele decreased the probability of having AD by about four fold. In conclusion, our data show a strong negative association between the P2X7R 489C>T polymorphism and AD, especially in the presence of the 1513C allele.