Involvement of Dihydropyrimidinase-Related Protein 2 in Regulation of Anxiety in Humans

Abstract

The goal of the study was analysis of the role for dihydropyrimidinase-related protein 2 (DRP2) in regulation of anxiety in humans and animals. For this purpose, the levels of DRP2 in the platelets and saliva and the levels of natural autoantibodies to DRP2 in the blood serum of the patients, admitted for a surgical operation, were analyzed alongside with the effects of DRP2 on rat behavior using the model of elevated plus-maze. Blood samples were collected from the veins of the patients, feeling anxiety at the day of surgery, into test tubes containing 5% EDTA as an anticoagulant. Platelets and serum were purified and through indirect ELISA-test the levels of DRP2 were evaluated in the platelets, while the levels of natural anti-DRP2 autoantibodies were measured in the blood serum. Concomitantly, the levels of DRP2 were estimated in the patients’ saliva sampled on the same day. The results showed upregulation of DRP2 in the platelets (p 0.05 on Student’s t-criterion) and natural anti-DRP2 autoantibodies in the serum of the patients (p 0.001) relative to healthy persons. Evaluation of the level of the stress hormone cortisol in the patients’ serum revealed its upregulation (p 0.01). At the same time downregulation of DRP2 in the patients’ saliva (p 0.01) was noticed. Intra-cerebral administration of DRP2 to the rats resulted in an increase in the number of crossed squares in the open arms of the maze relative to the control rats injected with inactivated DRP2 (p 0.01, Wilcoxon and Mann–Whitney U-criterion) which indicates their reduced anxiety. Based on the data obtained we conclude that evaluation of DRP2 in the platelets, natural anti-DRP2 autoantibodies in the blood serum and DRP2 in the saliva might serve as an indicator of anxiety levels in humans.