CircSYNDIG1 ameliorates stress-induced abnormal behaviors by suppressing miR-344-5p in mice

Advances in biosensors for major depressive disorder diagnostic biomarkers

Depression is one of the most common mental disorders and is mainly characterized by low mood or lack of interest and pleasure. It can be accompanied by varying degrees of cognitive and behavioral changes and may lead to suicide risk in severe cases. Due to the subjectivity of diagnostic methods and the complexity of patients' conditions, the diagnosis of major depressive disorder (MDD) has always been a difficult problem in psychiatry. With the discovery of more diagnostic biomarkers associated with MDD in recent years, especially emerging non-coding RNAs (ncRNAs), it is possible to quantify the condition of patients with mental illness based on biomarker levels. Point-of-care biosensors have emerged due to their advantages of convenient sampling, rapid detection, miniaturization, and portability. After summarizing the pathogenesis of MDD, representative biomarkers, including proteins, hormones, and RNAs, are discussed. Furthermore, we analyzed recent advances in biosensors for detecting various types of biomarkers of MDD, highlighting representative electrochemical sensors. Future trends in terms of new biomarkers, new sample processing methods, and new detection modalities are expected to provide a complete reference for psychiatrists and biomedical engineers.

The role of ncRNAs in depression

Depressive disorders have a significant impact on public health, and depression have an unsatisfactory recurrence rate and are challenging to treat. Non-coding RNAs (ncRNAs) are RNAs that do not code protein, which have been shown to be crucial for transcriptional regulation. NcRNAs are important to the onset, progress and treatment of depression because they regulate various physiological functions. This makes them distinctively useful as biomarkers for diagnosing and tracking responses to therapy among individuals with depression. It is important to seek out and summarize the research findings on the impact of ncRNAs on depression since significant advancements have been made in this area recently. Hence, we methodically outlined the findings of published researches on ncRNAs and depression, focusing on microRNAs. Above all, this review aims to improve our understanding of ncRNAs and provide new insights of the diagnosis and treatment of depression.

CircPTK2 may be associated with depressive-like behaviors by influencing miR-182-5p

BACKGROUND

Major depressive disorder (MDD) is a severe psychiatric disorder with uncertain causes. Recent studies have indicated correlations between circular RNAs (circRNAs) and psychiatric disorders. However, the potential role of circRNAs in MDD remains largely unknown.

METHODS

We investigated the expression and diagnostic significance of circRNA protein tyrosine kinase 2 (circPTK2) by recruiting 50 MDD patients and 40 healthy subjects. Additionally, chronic unpredictable mild stress (CUMS) mouse model was established in animal experiments. QRT-PCR was adopted for circPTK2 and miR-182-5p levels. To investigate the role of circPTK2 in MDD, we utilized microinjection of circPTK2 adeno-associated virus into the mouse hippocampus. Depressive-like behaviors of mice were assessed through forced swim test and open field test. Additionally, the interaction between circPTK2 and miR-182-5p was validated using a dual luciferase reporter assay.

RESULTS

Decreased expression of circPTK2 was found in peripheral blood mononuclear cells of MDD patients and in hippocampus of CUMS mice, which was useful for distinguishing MDD patients from healthy subjects. Notably, overexpression of circPTK2 was associated with depressive-like behaviors induced by CUMS. Further mechanism research demonstrated that circPTK2 functioned as the sponge for miR-182-5p, which may contribute to the beneficial effect of circPTK2.

CONCLUSION

Collectively, our findings suggest the participation of circPTK2 and its underlying mechanism in MDD, which might provide a potential target for MDD therapy.

Dulaglutide treatment reverses depression-like behavior and hippocampal metabolomic homeostasis in mice exposed to chronic mild stress

INTRODUCTION

Treatment strategies for depression based on interventions for glucose and lipid metabolism disorders are receiving increasing attention. Investigating the mechanism of their antidepressant effect and exploring new diagnostic and therapeutic biomarkers have attracted increasing attention. Dulaglutide, a long-acting GLP-1 receptor agonist, has been reported to alleviate cognitive deficits and neuronal damage. However, the antidepressant effect of dulaglutide and, especially, the underlying mechanism are still poorly understood. In this study, we aimed to explore the underlying biomarkers of depression and potential modulatory targets of dulaglutide in chronic mild stress (CMS) mice.

METHODS

Sixty mice were randomly divided into a control group (CON group), a CMS+Vehicle group (CMS+Veh group), a CMS+0.3 mg/kg dulaglutide group (Low Dula group), and a CMS+0.6 mg/kg dulaglutide group (High Dula group). Numerous behavioral tests, mainly the open field test, forced swimming test, and tail suspension test, were applied to evaluate the potential effect of dulaglutide treatment on anxiety- and depression-like behaviors in mice exposed to chronic stress. Furthermore, a liquid chromatography-tandem mass spectrometry-based metabolomics approach was utilized to investigate the associated mechanisms of dulaglutide treatment.

RESULTS

Three weeks of dulaglutide treatment significantly reversed depressive-like but not anxiety-like behaviors in mice exposed to chronic stress for 4 weeks. The results from the metabolomics analysis showed that a total of 20 differentially expressed metabolites were identified between the CON and CMS+Veh groups, and 46 metabolites were selected between the CMS+Veh and High Dula groups in the hippocampus of the mice. Comprehensive analysis indicated that lipid metabolism, amino acid metabolism, energy metabolism, and tryptophan metabolism were disrupted in model mice that experienced depression and underwent dulaglutide therapy.

CONCLUSION

The antidepressant effects of dulaglutide in a CMS depression model were confirmed. We identified 64 different metabolites and four major pathways associated with metabolic pathophysiological processes. These primary data provide a new perspective for understanding the antidepressant-like effects of dulaglutide and may facilitate the use of dulaglutide as a potential therapeutic strategy for depression.