Baseline levels of miR-223-3p correlate with the effectiveness of electroconvulsive therapy in patients with major depression

Integrative analysis of miRNA expression profiles reveals distinct and common molecular mechanisms underlying broad diagnostic groups of severe mental disorders

Micro RNAs (miRNAs) play a crucial role as regulators of various biological processes and have been implicated in the pathogenesis of mental disorders such as schizophrenia and bipolar disorders. In this study, we investigate the expression patterns of miRNAs in the PsyCourse Study (n = 1786), contrasting three broad diagnostic groups: Psychotic (Schizophrenia-spectrum disorders), Affective (Bipolar Disorder I, II and recurrent Depression), and neurotypic healthy individuals. Through comprehensive analyses, including differential miRNA expression, miRNA transcriptome-wide association study (TWAS), and predictive modelling, we identified multiple miRNAs unique to Psychotic and Affective groups as well as shared by both. Furthermore, we performed integrative analysis to identify the target genes of the dysregulated miRNAs and elucidate their potential roles in psychosis. Our findings reveal significant alterations of multiple miRNAs such as miR-584-3p and miR-99b-5p across the studied diagnostic groups, highlighting their role as molecular correlates. Additionally, the miRNA TWAS analysis discovered previously known and novel genetically dysregulated miRNAs confirming the relevance in the etiology of the diagnostic groups. Importantly, novel factors and putative molecular mechanisms underlying these groups were uncovered through the integration of miRNA-target gene interactions. This comprehensive investigation provides valuable insights into the molecular underpinnings of severe mental disorders, shedding light on the complex regulatory networks involving miRNAs.

MiR-223-3p inhibits hippocampal neurons injury and exerts anti- anxiety/depression-like behaviors by directly targeting NLRP3

Anxiety/depression disorders are among the most common neuropsychiatric conditions, and inflammation plays a significant role in their regulation. The involvement of miRNAs in the initiation, progression, and outcomes of anxiety disorders has been widely reported. Here, a decline in miR-223-3p expression was noticed in both IL-8-induced HT-22 cells and a rat model of anxiety/depression disorders treated with chronic unpredictable mild stress (CUMS). Our findings indicate that the overexpression of miR-223-3p significantly alleviates the effects of IL-8 on cell viability, inflammation, and oxidative stress in HT-22 cells, as verified by CCK-8 assay, ELISA assay, and flow cytometry. Through bioinformatics and luciferase reporter assays, NLRP3 was identified as a direct target of miR-223-3p. The inhibition of NLRP3 significantly reduced IL-8-induced damage to hippocampal neurons, while overexpression of NLRP3 reversed the protective effects of miR-223-3p. Moreover, increasing miR-223-3p levels significantly attenuated CUMS-induced anxiety/depression -like behaviors, such as decreased time in center in the open field test (OFT) and decreased time in open arm in the plus-maze test (EPM). The overexpression of miR-223-3p resulted in significant reductions in TNF-α, IL-1β, and SOD levels, an increase in MDA activity, as well as upregulation of cyclic adenosine monophosphate (cAMP), phosphorylated cAMP response element-binding protein (p-CREB), and brain-derived neurotrophic factor (BDNF) in the hippocampus. Overexpression of NLRP3 also reversed the effects of miR-223-3p in vivo. Thus, our research suggests that miR-223-3p can improve anxiety/depression-like behavior and inhibit hippocampal neuronal injury by targeting NLRP3, demonstrating its considerable anti-anxiety potential.

A role for astrocytic miR-129-5p in frontotemporal dementia

Frontotemporal dementia is a debilitating neurodegenerative disorder characterized by frontal and temporal lobe degeneration, resulting in behavioral changes, language difficulties, and cognitive decline. In this study, smallRNA sequencing was conducted on postmortem brain tissues obtained from the frontal and temporal of FTD patients with GRN, MAPT, or C9ORF72 mutations. Our analysis identified miR-129-5p as consistently deregulated across all analyzed mutation conditions and brain regions. Functional investigations in in-vitro models revealed a novel role of miR-129-5p in astrocytes, where its loss led to neuroinflammation and impaired neuronal support functions, including reduced glutamate uptake. Depletion of miR-129-5p in astrocytes also resulted in the loss of neuronal spines and altered neuronal network activity in a cell culture system. These findings highlight miR-129-5p as a potential therapeutic target in neurodegenerative diseases and also sheds light on the role of astrocytes in Frontotemporal dementia pathogenesis.

Response to electroconvulsive therapy is associated with a more diverse oral microbiome- a prospective longitudinal cohort pilot study

Recently it has been shown that psychiatric disorders are associated with changes in the host microbiome. Little is known about the association of electroconvulsive therapy (ECT) and microbiome alterations. In our pilot-study, 15 patients with severe or treatment resistant depression were prospectively recruited and oral swabs were collected pre- and post-ECT. Compared to a control group, ECT did not lead to a significant microbial shift in longitudinal samples (p = 0.65). However, alpha diversity measurements significantly differed between responders and non-responders before ECT (observed species p = 0.014, Shannon p = 0.03) and after ECT (observed species p = 0.015, Shannon p = 0.13).

Astrocytic NLRP3 cKO mitigates depression-like behaviors induced by mild TBI in mice

BACKGROUND

Reports indicate that depression is a common mental health issue following traumatic brain injury (TBI). Our prior research suggests that Nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3)-related neuroinflammation, modulated by glial cells such as astrocytes, is likely to play a crucial role in the progression of anxiety and cognitive dysfunction. However, there is limited understanding of the potential of astrocytic NLRP3 in treating depression under mild TBI condition. This study aimed to determine whether astrocytic NLRP3 knockout (KO) could mitigate depressive-like behaviors following mild TBI and explore potential variations in such behaviors between genders post-mild TBI.

METHODS

Mild TBI was induced in mice using Feeney's weight-drop method. Behavioral assessments included neurological severity scores (NSS), social interaction test (SI), tail suspension test (TST), and forced swimming test (FST). Pathological changes were evaluated through immunofluorescence and local field potential (LFP) recordings at various time points post-injury.

RESULTS

Our findings indicated that astrocyte-specific NLRP3 KO decreased cleaved caspase-1 colocalized with astrocytes, decreased pathogenic astrocytes and increased Postsynaptic density protein 95 (PSD95) intensity, and significantly alleviated mild TBI-induced depression-like behaviors. It also led to the upregulation of protective astrocytes and apoptosis-associated factors, including cleaved caspase-3 post-mild TBI. Additionally, astrocyte-specific NLRP3 deletion resulting in improved θ and γ power and θ-γ phase coupling in the social interaction test (SI). Notably, under mild TBI conditions, astrocyte-specific NLRP3 exhibited greater neuroprotective effects in female knockout mice compared to males.

CONCLUSION

Astrocyte NLRP3 knockout demonstrated a protective mechanism in mice subjected to mild TBI, possibly attributed to the inhibition of pyroptosis through the NLRP3 signaling pathway in astrocytes.

Prenatal Methamphetamine Exposure Impairs Helping Behaviour in Male Offspring: The Possible Role of miR-223 and NLRP3 Inflammasomes in the Amygdala

The increasing prevalence of methamphetamine abuse among women, particularly pregnant females, is a global concern. Methamphetamine can readily cross anatomical barriers like the blood-placenta barrier and cause detrimental impacts on the growing fetus. The current research evaluated the effects of prenatal methamphetamine exposure on helping behaviour and neuroinflammatory cascade in the amygdala of male offspring. On the tenth day of pregnancy, female rats received either saline or methamphetamine (5 mg/kg) until delivery. Once the offspring reached 21 days of age, the male ones were sep arated from their mothers and housed with normal male rats. An empathy-like behaviour test, which measured helping behaviour towards the cage mate, was conducted. The expression levels of miR-223-3p, NLRP3, Caspase 1, and gasdermin D (GSDMD) were evaluated in the amygdala of male offspring. Moreover, interleukin-1β (IL-1β) protein level was measured. Findings of this study revealed that male offspring exposed to methamphetamine during pregnancy had impaired helping behaviour. At the molecular level, prenatal methamphetamine exposure decreased miR-223-3p and increased inflammasome signaling by raising the levels of NLRP3, caspase-1, and GSDMD along with IL-1β levels. These findings indicate that prenatal methamphetamine exposure impairs emotional behaviour and activates inflammasome pathway in the amygdala.

The underlying mechanisms of the association of bone health with depression - an experimental study

BACKGROUND

Depression constitutes a risk factor for osteoporosis, but underlying molecular and cellular mechanisms are not fully understood. MiRNAs influence gene expression and are carried by extracellular vesicles (EV), affecting cell-cell communication.

AIMS

(1) Identify the difference in miRNA expression between depressed patients and healthy controls; (2) Analyze associations of these miRNAs with bone turnover markers; (3) Analyze target genes of differentially regulated miRNAs and predict associated pathways regarding depression and bone metabolism.

METHODS AND RESULTS

Blood samples from depressed patients (n = 11) were obtained from a previous study and healthy controls (n = 9) were recruited. Sociodemographic, depression diagnosis and depressive symptom (BDI-II) data were collected through questionnaires. Blood plasma was collected from each participant and real-time-quantitative PCR was performed on isolated plasma EVs; differences in miRNA expression between groups were analyzed using qbase+. Regression models assessed the associations of differentially regulated miRNAs with bone turnover markers procollagen-1 N-terminal-peptide, osteocalcin, and crosslaps; enriched pathways and miRNA target gene networks were analyzed. 19 miRNAs were differentially expressed between groups (p < 0.05). MiR-26b-5p and miR-106a-5p showed an association with procollagen-1 N-terminal-peptide; miR-330-5p and miR-377-3p were associated with osteocalcin, and miR-26b-5p, miR-34c-3p and miR-145 with crosslaps. Pathway analysis including the differentially expressed miRNAs predicted enriched pathways, including the FoxO signaling and p53 signaling pathway. Seven target genes were identified.

CONCLUSIONS

MiRNAs (e.g. miR-26b-5p, miR-377-3p), genes (TNRC6B, HSPA8), and pathways (FoxO- and Hippo-signaling pathway) are identified which could be mediators between the influence of depression on bone health and could possibly serve as biomarkers in the treatment of bone diseases among people with mental disorders.

FOXO1-mediated autophagy regulation by miR-223 in sepsis-induced immunosuppression

Introduction

Immunosuppression is the main cause of the high mortality rate in patients with sepsis. The decrease in the number and dysfunction of CD4+ T lymphocytes is crucial to the immunosuppressed state of sepsis, in turn affecting the development and prognosis of sepsis. Autophagy has been shown to play an important role in the immune imbalance exhibited during sepsis.

Methods

In this study, we modulate the expression of miR-223 in CD4+ T lymphocytes, via the transfection of a mimic or an inhibitor of miR-223 to establish cell models of miR-223 overexpression and knockdown, respectively. Levels of autophagy were monitored using a double-labeled lentivirus (mRFP-GFP-LC3) and electron microscopy, and western blot analysis was used to estimate the levels of autophagy-related proteins and FOXO1 in the two cell models after co-treatment with lipopolysaccharide (LPS) and siRNA against FOXO1.

Results

We found that when the expression of miR-223 increased, FOXO1 expression decreased and autophagy decreased; whereas, when FOXO1 expression was inhibited, autophagy decreased significantly in different cell models after LPS induction.

Conclusion

Thus, this study proved that miR-223 participate in the regulation of LPS-induced autophagy via the regulation of FOXO1 expression in CD4+ T lymphocytes which shed a new light for the diagnosis and treatment of sepsis.

Systems biology dissection of PTSD and MDD across brain regions, cell types, and blood

The molecular pathology of stress-related disorders remains elusive. Our brain multiregion, multiomic study of posttraumatic stress disorder (PTSD) and major depressive disorder (MDD) included the central nucleus of the amygdala, hippocampal dentate gyrus, and medial prefrontal cortex (mPFC). Genes and exons within the mPFC carried most disease signals replicated across two independent cohorts. Pathways pointed to immune function, neuronal and synaptic regulation, and stress hormones. Multiomic factor and gene network analyses provided the underlying genomic structure. Single nucleus RNA sequencing in dorsolateral PFC revealed dysregulated (stress-related) signals in neuronal and non-neuronal cell types. Analyses of brain-blood intersections in >50,000 UK Biobank participants were conducted along with fine-mapping of the results of PTSD and MDD genome-wide association studies to distinguish risk from disease processes. Our data suggest shared and distinct molecular pathology in both disorders and propose potential therapeutic targets and biomarkers.

miRNAs in treatment-resistant depression: a systematic review

BACKGROUND

Treatment-resistant depression (TRD) is a condition in a subset of depressed patients characterized by resistance to antidepressant medications. The global prevalence of TRD has been steadily increasing, yet significant advancements in its diagnosis and treatment remain elusive despite extensive research efforts. The precise underlying pathogenic mechanisms are still not fully understood. Epigenetic mechanisms play a vital role in a wide range of diseases. In recent years, investigators have increasingly focused on the regulatory roles of miRNAs in the onset and progression of TRD. miRNAs are a class of noncoding RNA molecules that regulate the translation and degradation of their target mRNAs via interaction, making the exploration of their functions in TRD essential for elucidating their pathogenic mechanisms.

METHODS AND RESULTS

A systematic search was conducted in four databases, namely PubMed, Web of Science, Cochrane Library, and Embase, focusing on studies related to treatment-resistant depression and miRNAs. The search was performed using terms individually or in combination, such as "treatment-resistant depression," "medication-resistant depression," and "miRNAs." The selected articles were reviewed and collated, covering the time period from the inception of each database to the end of February 2024. We found that miRNAs play a crucial role in the pathophysiology of TRD through three main aspects: 1) involvement in miRNA-mediated inflammatory responses (including miR-155, miR-345-5p, miR-146a, and miR-146a-5p); 2) influence on 5-HT transport processes (including miR-674,miR-708, and miR-133a); and 3) regulation of synaptic plasticity (including has-miR-335-5p,has-miR- 1292-3p, let-7b, and let-7c). Investigating the differential expression and interactions of these miRNAs could contribute to a deeper understanding of the molecular mechanisms underlying TRD.

CONCLUSIONS

miRNAs might play a pivotal role in the pathogenesis of TRD. Gaining a deeper understanding of the roles and interrelations of miRNAs in TRD will contribute to elucidating disease pathogenesis and potentially provide avenues for the development of novel diagnostic and therapeutic strategies.

Clinical Insights into MicroRNAs in Depression: Bridging Molecular Discoveries and Therapeutic Potential

Depression is a major contributor to the overall global burden of disease. The discovery of biomarkers for diagnosis or prediction of treatment responses and as therapeutic agents is a current priority. Previous studies have demonstrated the importance of short RNA molecules in the etiology of depression. The most extensively researched of these are microRNAs, a major component of cellular gene regulation and function. MicroRNAs function in a temporal and tissue-specific manner to regulate and modify the post-transcriptional expression of target mRNAs. They can also be shuttled as cargo of extracellular vesicles between the brain and the blood, thus informing about relevant mechanisms in the CNS through the periphery. In fact, studies have already shown that microRNAs identified peripherally are dysregulated in the pathological phenotypes seen in depression. Our article aims to review the existing evidence on microRNA dysregulation in depression and to summarize and evaluate the growing body of evidence for the use of microRNAs as a target for diagnostics and RNA-based therapies.