Expression of major ectonucleotidases after cortical stab brain injury in rats: A real-time PCR study

Abstract

Ectonucleotidases are cell surface-located enzymes responsible for the extracellular degradation of nucleotides. They are comprised of several protein families: ectonucleoside triphosphate diphosphohydrolases (E-NTPDase), ectonucleotide pyrophosphatase/phosphodiesterases (E-NPPases) and ecto-5'-nucleotidase. Previously we showed that cortical stab injury alters ectonucleotidase activities in the rat brain, but that the specific enzymes responsible for these changes were not identified. In this study we investigated the gene expression of the specific ectonucleotidase enzymes, NTP-Dase1-3, NPP1-3 and ecto-5'-nucleotidase, two and seven days after cortical stab injury in rats, using real-time PCR. Two days after the injury we observed only one significant change: the downregulation in NTPDase2 mRNA expression. Our results indicate that traumatic brain injury induces significant upregulation of NTPDasel, NTPDase2 and ecto-5'-nucleotidase transcripts, and the downregulation of NPP1, seven days after the injury. Thus, traumatic brain injury has diverse impacts on ectonucleotidases gene expression, which may be reflected in the enzyme activities and extracellular nucleotide concentrations in the perilesional tissue.