ABSTRACT
ETS-1 is a transcription factor that is a member of the E26 transformation-specific (ETS) family. Galanin receptor 2 (GalR2), a subtype of receptors of the neuropeptide galanin, has been shown to have an antidepressant-like effect after activation in rodents. Our previous study has shown that overexpression of ETS-1 increases the expression of GalR2 in PC12 phaeochromocytoma cells. However, whether ETS-1 has an antidepressant-like effect is still unclear. In this study, we found that chronic mild stress (CMS) decreased the expression of both ETS-1 and GalR2 in the ventral hippocampus of rats. Meanwhile, we demonstrated that overexpression of ETS-1 increased the expression of GalR2 in primary hippocampal neurons. Importantly, we showed that overexpression of ETS-1 in the ventral hippocampus counteracted the depression-like behaviors of CMS rats. Furthermore, we found that overexpression of ETS-1 increased the level of downstream phosphorylated extracellular signal-regulated protein kinases 1 and 2 (p-ERK1/2) of GalR2 in the ventral hippocampus of CMS rats. Taken together, our findings suggest that ETS-1 has an antidepressant-like effect in rats, which might be mediated by increasing the level of GalR2 and its downstream p-ERK1/2 in the ventral hippocampus.
ABSTRACT
@#Objective To construct dual-luciferase reporter plasmids containing the wild type and mutant rat extracellular signal-regulat-ed kinase 1 (ERK1) gene 3' untranslated regions (UTR) which were used to detect rno-miR-15b-5p's putative target gene. Methods The rat ERK1 gene 3' UTR fragment was amplified by polymerase chain reaction (PCR) from PC12 cell cDNA and cloned into pmiR-RB-ReportTM vector. The mutant rat ERK1 gene 3' UTR fragment was obtained by overlap PCR and inserted into pmiR-RB-ReportTM vector. Successful wild type and mutant recombinant plasmids were confirmed by DNA sequencing. PC12 cells were co-transfected with rno-miR-15b-5p mim-ic and pmiR-ERK13' UTR or pmiR-ERK1-mut 3' UTR and then analyzed by dual-luciferase reporter assay system. The achieved mutation sequence of the target site TGCTGCT was mutated to CGAACGT and GTACACG, respectively. Results The wild-type reporter vector pmiR-ERK13' UTR and the mutant reporter vector pmiR-ERK1-mut 3' UTR were successfully constructed. The rno-miR-15b-5p mimic de-creased the activity of pmiR-ERK13' UTR plasmid (P<0.001) but did not decrease the activity of pmiR-ERK1-mut 3' UTR plasmid. Conclu-sion The recombinant pmiR-ERK13' UTR and pmiR-ERK1-mut 3' UTR plasmids were constructed successfully, and luciferase activities demonstrated that the 3' UTR of ERK1 gene might be a potential target of rno-miR-15b-5p.