Antidepressant-Like Effect and Mechanism of Ginsenoside Rd on Rodent Models of Depression

Background

There is growing evidence to suggest that ginsenoside Rd (GRd) has a therapeutic effect on depression, but the specific mechanisms behind its activity require further study.

Objective

This study is designed to investigate the antidepressant-like effect and underlying mechanisms of GRd.

Methods

In this study, the behavioral despair mouse model of depression and chronic unpredictable mild stress (CUMS) rat model of depression were established to explore the effects of GRd on depression-like behavior and its underlying mechanisms. Behavioral tests were used to evaluate the replication of animal models and depression-like behaviors. The hypoxia-inducible factor-1α (HIF-1α) blocker 2-methoxyestradiol (2-ME) was injected to determine the role of HIF-1α in the antidepressant-like effect of GRd. In addition, molecular biology techniques were used to determine the mRNA and protein expression of HIF-1ɑ signaling pathway and synaptic plasticity-related regulators, that is synapsin 1 (SYN 1) and postsynaptic density protein 95 (PSD 95). In silico binding interaction studies of GRd with focused target proteins were performed using molecular docking to predict the affinity and optimal binding mode between ligands and receptors.

Results

Our data show that GRd significantly reversed depression-like behavior and promoted mRNA and protein expression of HIF-1ɑ signaling pathway and synaptic plasticity-related regulators. However, the antidepressant-like effect of GRd disappeared upon inhibition of HIF-1α expression following administration of 2-ME. Furthermore, molecular docking results showed that GRd possessed significant binding affinity for HIF-1α, VEGF, and VEGFR-2.

Conclusion

Our results show that GRd exhibits significant antidepressant-like effect and that HIF-1α signaling pathway is a promising target for the treatment of depression.

miR-152-3p aggravates vascular endothelial cell dysfunction by targeting DEAD-box helicase 6 (DDX6) under hypoxia

Stroke is a main cause of disability and death worldwide, and ischemic stroke accounts for most stroke cases. Recently, microRNAs (miRNAs) have been verified to play critical roles in the development of stroke. Herein, we explored effects of miR-152-3p on vascular endothelial cell functions under hypoxia. Human umbilical vein endothelial cells (HUVECs) were treated with hypoxia to mimic cell injury in vitro. Reverse transcription quantitative polymerase chain reaction revealed that miR-152-3p exhibited high expression in HUVECs treated with hypoxia. The inhibition of miR-152-3p reversed hypoxia-induced decrease in cell viability and the increase in angiogenesis, according to the results of cell counting kit-8 assays and tube formation assays. miR-152-3p inhibition reversed the increase in endothelial cell permeability mediated by hypoxia, as shown by endothelial cell permeability in vitro assays. In addition, the increase in protein levels of angiogenetic markers and the decrease in levels of tight junction proteins induced by hypoxia were reversed by miR-152-3p inhibition. Mechanistically, miR-152-3p directly targets 3ʹ-untranslated region of DEAD-box helicase 6 (DDX6), which was confirmed by luciferase reporter assays. DDX6 is lowly expressed in HUVECs under hypoxic condition, and mRNA expression and protein level of DDX6 were upregulated in HUVECs due to miR-152-3p inhibition. Rescue assays showed that DDX6 knockdown reversed effects of miR-152-3p on cell viability, angiogenesis and endothelial permeability. The results demonstrated that miR-152-3p aggravates vascular endothelial cell dysfunction by targeting DDX6 under hypoxia.

Post-transcriptional regulation of miRNA-15a and miRNA-15b on VEGFR gene and deer antler cell proliferation

Background

Deer antler is the only regenerative organ in mammals, the regeneration of antler is not only the regeneration of bone tissue, but also accompanied by the regeneration of nerves, blood vessels and so on. The purpose of the current study was to explore the effect of miRNA-15a and miRNA-15b on the regulation of sika deer vascular endothelial growth factor receptor (VEGFR) during rapid antler growth.

Materials and methods

The VEGFR 3′-UTR was analyzed by bioinformatics software to identify the highly matched miRNAs. After transfected with miRNA mimics, the expression of selected miRNAs were measured by RT-qPCR and the relative expression level of VEGFR protein was detected by Western Blot. Dual-luciferase activity assay was used to determine the target relationship between VEGFR and miRNAs. The cartilage cell proliferation and telomerase activity were measured by MTT kit and TRAP assay, respectively.

Results

The VEGFR 3′-UTR contains a binding site for miRNA-15a and miRNA-15b. Over-expression of miRNA-15a and miRNA-15b, which significantly reduced the expression level of VEGFR protein, inhibited the proliferation of cartilage cells, and decreased the telomerase activity of cartilage cells in vitro.

Conclusion

miRNA-15a and miRNA-15b represent novel regulatory factors of VEGFR expression in deer antler.