Cplx2 gene expression following semax or PGP administration under conditions of two experimental models of rat-brain ischemia

Abstract

Complexin 2 is a cytosolic protein participating in synaptic-vesicle exocytosis. The RT-PCR technique was used in a real-time study of the dynamics of variation of expression of the Cplx2 gene that encodes this protein. The study was performed in the rat brain. Measurements under the conditions of incomplete global ischemia were performed during 1 day; measurements under the conditions of focal ischemia were carried out 3, 24, and 72 h after irreversible occlusion of the medial cerebral artery. The most significant decrease in Cplx2 transcripts under the conditions of incomplete global ischemia was observed in the hippocampus and the frontal cortex of rats 12 and 24 h after irreversible occlusion of the common carotid arteries, respectively. Under conditions of focal ischemia, a decrease in the content of Cplx2 transcripts was observed only in focal lesions of the frontoparietal cortex 24 h after occlusion. The effect of Semax neuroprotector peptide and its C-terminal fragment Pro-Gly-Pro on Cplx2 expression was examined under the model ischemia conditions. In the case of incomplete global ischemia, application of Semax compensated for the maximum decrease in Cplx2 expression in the frontal cortex and hippocampus in rats caused by lesions. However, the peptide had no effect when used in rats with focal ischemia. The effect of PGP on Cplx2 expression under conditions of experimental ischemia was more complicated and did not always coincide with the effect of Semax. The obtained results provide insight into the specific features of Cplx2 expression under the conditions of experimental brain ischemia and help to better understand the mechanisms of activity of peptide preparations.