Aberrant resting state in microRNA-30e rat model of cognitive impairment

Plasma metabolomics and network pharmacology identified glutamate, glutamine, and arginine as biomarkers of depression under Shuganjieyu capsule treatment

Depression is a psychiatric disorder and confers an enormous burden on society. Mild to moderate forms of depression (MMD) are particularly common. Our previous studies showed that the Shuganjieyu (SGJY) capsule might improve depressive and cognitive symptoms in patients with MMD. However, biomarkers evaluating the efficacy of SGJY and the underlying mechanism remains unclear. The aim of the present study was to discover efficacy biomarkers and explore the underlying mechanisms of SGJY as antidepression treatment. Twenty-three patients with MMD were recruited and administered with SGJY for 8 weeks. Results showed that the content of 19 metabolites changed significantly in the plasma of patients with MMD, among which 8 metabolites improved significantly after SGJY treatment. Network pharmacology analysis showed that 19 active compounds, 102 potential targets, and 73 enzymes were related to the mechanistic action of SGJY. Through a comprehensive analysis, we identified four hub enzymes (GLS2, GLS, GLUL, and ADC), three key differential metabolites (glutamine, glutamate, and arginine), and two shared pathways (alanine, aspartate, and glutamate metabolism; and arginine biosynthesis). Receiver operating characteristic curve (ROC) analysis showed that the three metabolites had a high diagnostic ability. The expression of hub enzymes was validated using RT-qPCR in animal models. Overall, glutamate, glutamine, and arginine may be potential biomarkers for evaluating the efficacy of SGJY. The present study provides a new strategy for pharmacodynamic evaluation and mechanistic study of SGJY, and offers new information for clinical practice and treatment research.

The important roles of microRNAs in depression: new research progress and future prospects

MicroRNAs (miRNAs) are non-encoding, single-stranded RNA molecules of about 22 nucleotides in length encoded by endogenous genes involved in posttranscriptional gene expression regulation. Studies have shown that miRNAs participate in a series of important pathophysiological processes, including the pathogenesis of depression. This article systematically summarized the research results published in the field of miRNAs and depression, which mainly involved three topics: circulating miRNAs as markers for diagnosis and prognosis of depression, the regulatory roles of miRNAs in the pathogenesis of depression, and the roles of miRNAs in the mechanisms of depression treatment. By summarizing and analyzing the research literature in recent years, we found that some circulating miRNAs can be potential biomarkers for the diagnosis and prognostic evaluation of depression. miRNAs that disorderly expressed during the disease play important roles in the depression pathogenesis, and miRNAs also play roles in the mechanisms of psychotherapy and drug therapy for depression. Elucidating the important roles of miRNAs in depression will bring people's understanding of the pathogenesis of depression to a new level. In addition, these miRNAs may be developed as new biomarkers for diagnosing depression, or as drug targets, or these molecules may be used as new drugs, which may provide new means for the treatment of depression. KEY MESSAGES: • The research results of miRNAs and depression are reviewed. • Circulating miRNAs can be potential biomarkers for depression. • MiRNAs play important roles in the depression pathogenesis. • MiRNAs play important roles in drug therapy for depression.

Improve cognition of depressive patients through the regulation of basal ganglia connectivity: Combined medication using Shuganjieyu capsule

Shuganjieyu capsule (Shugan) is a combined extract of Hypericum perforatum (HP) and Eleutherococcus senticosus (ES). Both HP and ES have been proven effective in the treatment of depression and impaired cognition. However, for mild to moderate depression (MMD), the treatment effect and underlying mechanism by combining both HP and ES are largely unknown. Here, we aim to evaluate the therapeutic effects on impaired cognition using Shugan, a combined medication of HP and ES. Resting-state magnetic resonance imaging (MRI) data and cognitive assessment have been collected from 54 healthy controls and 55 MMD patients that have been undergoing 8-week Shugan-treatment. The functional connectivity (FC) and brain region volume changes of the basal ganglia seeded circuit have been measured, and their relation with the cognitive assessment score was calculated. After that, a literature-based pathway analysis has been conducted to explore the biological relations among Shugan, brain regions, and depression. Compared to healthy controls, MMD patients demonstrated a significantly higher FC (P= 0.0025) between right ventral caudate (vCa) and left orbitofrontal cortex (OFC), which was decreased after the treatment (P < 0.001). A volume of the right caudate, which is increased in MMD, has also been reduced by Shugan treatment (P= 0.017). Importantly, the cognitive scores were strongly correlated with both Shugan treatment and the FC between vCa and OFC (r= 0.321, P= 0.02). Besides, we identified multiple signaling pathways, through which Shugan might improve the cognition of MMD patients. Our results support the therapeutic effects of Shugan on cognition in MMD, which may be realized partly through the regulation within two brain regions, vCa and OFC.

Total Salvianolic Acid Balances Brain Functional Network Topology in Rat Hippocampi Overexpressing miR-30e

We investigated the therapeutic effects and underlying brain functional network topology mechanisms of total salvianolic acid (TSA) treatment for memory dysfunction by using miR-30e overexpression-induced memory deficit in rat hippocampi. Model rats were developed by lentivirus vectors carrying miR-30e into bilateral hippocampus CA1 region through stereo-surgery. Two weeks after surgery, TSA (20 or 10 mg/mL/kg) or saline were administrated for 14 consecutive days. Memory function was assessed by behavioral tests (Y maze and Morris water maze [MWM]); resting-state functional MRI (RS-fMRI); and molecular alterations of BCL-2, UBC9, and Caspase-3 in the hippocampus CA1 region, as detected by immunohistochemistry. Compared to controls, model rats exhibited significantly impaired working and long-term memory in the Y maze and MWM tests (p < 0.01). The brain functional network topology analyzed based on RS-fMRI data demonstrated that miR-30e disturbed the global integration and segregation balance of the brain (p < 0.01), and reduced edge strength between CA1 and the posterior cingulate, temporal lobe, and thalamus (p < 0.05, false discovery rate corrected). At the molecular level, BCL-2 and UBC9 were downregulated, while Caspase-3 was upregulated (p < 0.01). After TSA (20 mg/mL/kg) treatment, the biomarkers for behavioral performance, global integration and segregation, edge strength, and expression levels of BCL-2, UBC9, and Caspase3 returned to normal levels. The correlation analyses of these results showed that global brain functional network topologic parameters can be intermediate biomarkers correlated with both behavioral changes and molecular alterations. This indicated that the effects of TSA were achieved by inhibiting apoptosis of CA1 neurons to improve global functional network topology.

Co-Variation of Peripheral Levels of miR-1202 and Brain Activity and Connectivity During Antidepressant Treatment

MicroRNAs are short non-coding molecules that play a major role in regulating gene expression. Peripheral levels of miR-1202 have been shown to predict and mediate antidepressant response. However, it is not clear to what extent these peripheral measures reflect central neural changes in vivo. We approached this problem with the combined use of peripheral miR-1202 measures and neuroimaging. At baseline and after 8 weeks of desvenlafaxine (50-100 mg die), 20 patients were scanned with 3T magnetic resonance imaging, first at rest then during the Go/NoGo task, a classical test of response inhibition. Blood samples were collected at both time points. During resting state, lower baseline miR-1202 levels were predictive of increased connectivity from T0 to T8 between the posterior cingulate and the prefrontal, parietal, and occipital cortices. Changes in miR-1202 levels following desvenlafaxine treatment were negatively correlated with changes in activity in right precuneus within the default-mode network, and in connectivity between the posterior cingulate and the temporal and prefrontal cortices, and the precuneus. During the Go/NoGo task, baseline miR-1202 levels and changes in these levels were correlated with activity changes in different regions, including bilateral prefrontal, insular, cingulate, and temporal cortices, and left putamen and claustrum. Finally, secondary analyses in a subset of patients showed a trend for a significant correlation between miR-1202 levels and glutamate levels measured by spectroscopy. Changes in peripheral miR-1202 levels were therefore associated with changes in brain activity and connectivity in a network of brain regions associated with depression and antidepressant response. These effects may be mediated by the glutamatergic system.