Antistress Action of Melanocortin Derivatives Associated with Correction of Gene Expression Patterns in the Hippocampus of Male Rats Following Acute Stress

Abstract

Natural melanocortins (MCs) have been used in the successful development of drugs with neuroprotective properties. Here, we studied the behavioral effects and molecular genetic mechanisms of two synthetic MC derivatives-ACTH(4–7)PGP (Semax) and ACTH(6–9)PGP under normal and acute restraint stress (ARS) conditions. Administration of Semax or ACTH(6–9)PGP (100 μg/kg) to rats 30 min before ARS attenuated ARS-induced behavioral alterations. Using high-throughput RNA sequencing (RNA-Seq), we identified 1359 differentially expressed genes (DEGs) in the hippocampus of vehicle-treated rats subjected to ARS, using a cutoff of >1.5 fold change and adjusted p-value (Padj) < 0.05, in samples collected 4.5 h after the ARS. Semax administration produced >1500 DEGs, whereas ACTH(6–9)PGP administration led to <400 DEGs at 4.5 h after ARS. Nevertheless, ~250 overlapping DEGs were identified, and expression of these DEGs was changed unidirectionally by both peptides under ARS conditions. Modulation of the expression of genes associated with biogenesis, translation of RNA, DNA replication, and immune and nervous system function was produced by both peptides. Furthermore, both peptides upregulated the expression levels of many genes that displayed decreased expression after ARS, and vice versa, the MC peptides downregulated the expression levels of genes that were upregulated by ARS. Consequently, the antistress action of MC peptides may be associated with a correction of gene expression patterns that are disrupted during ARS.

Comparative Use of Contralateral and Sham-Operated Controls Reveals Traces of a Bilateral Genetic Response in the Rat Brain after Focal Stroke

“…It was shown that the phospholipase A2 activity induced by Pla-family genes was associated not only with ischemic stroke but also with Alzheimer's disease and vascular dementia [39]. Moreover, the Pla2g3 gene was included in the top five upregulated genes in the rat hippocampus in response to acute stress [40]. Previous studies have shown that the anti-inflammatory S-2474 drug rescues cortical neurons from human group IIA secretory phospholipase A(2)-induced apoptosis [41].…”

“…Total RNA was isolated as previously described [40]. RNA integrity was checked using capillary electrophoresis (Experion, BioRad, Hercules, CA, USA).…”

“…The RNA-Seq analysis of the polyA fraction of the total RNA was conducted with the participation of ZAO Genoanalytika, Moscow, Russia, using an Illumina HiSeq 1500 instrument (Illumina, San Diego, CA, USA) as previously described [40]. At least 10 million reads (1/50 nt) were generated.…”

“…cDNA synthesis was conducted as previously described [40]. Oligo (dT) 18 primers were used to analyse mRNA.…”

“…The polymerase chain reaction (PCR) was conducted using a StepOnePlus Real-Time PCR System (Applied Biosystems, Foster City, CA, USA) as previously described [40]. Primers specific to the genes studied were selected using OLIGO Primer Analysis Software version 6.31 and were synthesized by the Evrogen Joint Stock Company (Supplementary Table S7).…”