Bipolar Disorder

Uncovering the therapeutic potentials of marine-derived natural compounds with small amounts for neurological disorders

The discovery of novel drugs from the ocean is a relatively recent development. However, for most studies of marine drugs, the priority is the discovery of compounds with new structures. Normally, only small amounts (< 1 mg) of new compounds could be extracted from marine microbes, and it is difficult to evaluate the therapeutic potentials of these newly-identified marine-derived natural compounds by traditional cell- or animal-based phenotypic screenings. Genes play a crucial role in determining the phenotype of diseases and the action of drugs. By comparing genomic expression associated with disease conditions and compound treatments, it is possible to predict the potential of a certain compound to counteract a specific type of disease. In this study, marine-derived natural compounds-induced genomic changes in cells were collected either from public databases or by using RNA-seq analysis. The therapeutic potentials of representative marine-derived natural compounds, namely phycocyanobilin, cycloheximide and NBU-1, a newly-identified natural compound extracted from a marine sponge-associated Streptomyces, on bipolar disorder (BD), Parkinson's disease (PD) and Alzheimer's disease (AD), were predicted by gene set enrichment analysis (GSEA), respectively. The anti-neurological disorder activity of these marine-derived natural compounds were further validated in methamphetamine-induced rats mimicking manic phase of BD, 6-OHDA-treated PC12 cells mimicking PD neurotoxicity and β-amyloid oligomer-incubated SH-SY5Y cells mimicking AD neuronal loss. Our study provides not only new insights for pharmacological applications of the marine-derived natural compounds here studied, but also a method for predicting and evaluating therapeutic potentials of newly-identified marine-derived natural compounds with small quantities.

Hippocampal transcriptome analysis in ClockΔ19 mice identifies pathways associated with glial cell differentiation and myelination

BACKGROUND

ClockΔ19 mice demonstrate behavioral characteristics and neurobiological changes that closely resemble those observed in bipolar disorder (BD). Notably, abnormalities in the hippocampus have been observed in patients with BD, yet direct molecular investigation of human hippocampal tissue remains challenging due to its limited accessibility.

METHODS

To model BD, ClockΔ19 mice were employed. Weighted gene co-expression network analysis (WGCNA) was utilized to identify mutation-related modules, and changes in cell populations were determined using the computational deconvolution CIBERSORTx. Furthermore, GeneMANIA and protein-protein interactions (PPIs) were leveraged to construct a comprehensive interaction network.

RESULTS

174 differentially expressed genes (DEGs) were identified, revealing abnormalities in rhythmic processes, mitochondrial metabolism, and various cell functions including morphology, differentiation, and receptor activity. Analysis identified 5 modules correlated with the mutation, with functional enrichment highlighting disturbances in rhythmic processes and neural cell differentiation due to the mutation. Furthermore, a decrease in neural stem cells (NSC), and an increase in astrocyte-restricted precursors (ARP), ependymocytes (EPC), and hemoglobin-expressing vascular cells (Hb-VC) in the mutant mice were observed. A network comprising 12 genes that link rhythmic processes to neural cell differentiation in the hippocampus was also identified.

LIMITATIONS

This study focused on the hippocampus of mice, hence the applicability of these findings to human patients warrants further exploration.

CONCLUSION

The ClockΔ19 mutation may disrupt circadian rhythm, myelination, and the differentiation of neural stem cells (NSCs) into glial cells. These abnormalities are linked to altered expression of key genes, including DPB, CIART, NR1D1, GFAP, SLC20A2, and KL. Furthermore, interactions between SLC20A2 and KL might provide a connection between circadian rhythm regulation and cell type transitions.

From Stress to Synapse: The Neuronal Atrophy Pathway to Mood Dysregulation

Mood disorders, including major depressive disorder and bipolar disorder, are among the most prevalent mental health conditions globally, yet their underlying mechanisms remain incompletely understood. This review critically examines the neuronal atrophy hypothesis, which posits that chronic stress and associated neurobiological changes lead to structural and functional deficits in critical brain regions, contributing to mood disorder pathogenesis. Key mechanisms explored include dysregulation of neurotrophic factors such as brain-derived neurotrophic factor (BDNF), elevated glucocorticoids from stress responses, neuroinflammation mediated by cytokines, and mitochondrial dysfunction disrupting neuronal energy metabolism. These processes collectively impair synaptic plasticity, exacerbate structural atrophy, and perpetuate mood dysregulation. Emerging evidence from neuroimaging, genetic, and epigenetic studies underscores the complexity of these interactions and highlights the role of environmental factors such as early-life stress and urbanization. Furthermore, therapeutic strategies targeting neuroplasticity, including novel pharmacological agents, lifestyle interventions, and anti-inflammatory treatments, are discussed as promising avenues for improving patient outcomes. Advancing our understanding of the neuronal atrophy hypothesis could lead to more effective, sustainable interventions for managing mood disorders and mitigating their global health burden.

Exploring accelerated aging as a target of bipolar disorder treatment: A systematic review

Bipolar disorder (BD) has been linked to accelerated aging processes, with many studies suggesting that drugs used to treat BD may modulate pathways related to aging. This systematic review aimed to determine whether FDA-approved pharmacotherapies for BD have reported effects on aging biomarkers across clinical and preclinical studies. We conducted searches in PubMed and PsychINFO and followed PRISMA guidelines. Out of 6400 records identified, 19 studies met the inclusion criteria. Most preclinical studies tested the effects of BD drugs, especially lithium, on lifespan and telomere biology in cell and animal models. Clinical studies predominantly focused on lithium, evaluating aging markers like telomere length, telomerase, mitochondrial DNA copy number, and epigenetic age acceleration in individuals with BD. Findings indicate that chronic lithium treatment is associated with modulatory effects on aging biomarkers, particularly increased telomere length and telomerase activity. Conversely, some negative results were also reported. Limited evidence suggests potential aging-modulating properties of other mood stabilizers like valproic acid and lamotrigine, evidencing that further investigation is required. Despite variability across studies, the overall findings support the notion that pharmacotherapies used in BD present many effects of aging biomarkers. However, the field is still developing, with a clear emphasis on lithium and a lack of standardized methods to evaluate aging biomarkers in clinical samples. Further research exploring the anti-accelerated aging effects of BD drugs beyond lithium, their mechanisms of action, and potential synergistic effects is warranted.

Molecular Modeling and In Vitro Functional Analysis of the RGS12 PDZ Domain Variant Associated with High-Penetrance Familial Bipolar Disorder

Bipolar disorder's etiology involves genetics, environmental factors, and gene-environment interactions, underlying its heterogeneous nature and treatment complexity. In 2020, Forstner and colleagues catalogued 378 sequence variants co-segregating with familial bipolar disorder. A notable candidate was an R59Q missense mutation in the PDZ (PSD-95/Dlg1/ZO-1) domain of RGS12. We previously demonstrated that RGS12 loss removes negative regulation on the kappa opioid receptor, disrupting basal ganglia dopamine homeostasis and dampening responses to dopamine-eliciting psychostimulants. Here, we investigated the R59Q variation in the context of potential PDZ domain functional alterations. We first validated a new target for the wildtype RGS12 PDZ domain-the SAPAP3 C-terminus-by molecular docking, surface plasmon resonance (SPR), and co-immunoprecipitation. While initial molecular dynamics (MD) studies predicted negligible effects of the R59Q variation on ligand binding, SPR showed a significant reduction in binding affinity for the three peptide targets tested. AlphaFold2-generated models predicted a modest reduction in protein-peptide interactions, which is consistent with the reduced binding affinity observed by SPR, suggesting that the substituted glutamine side chain may weaken the affinity of RGS12 for its in vivo binding targets, likely through allosteric changes. This difference may adversely affect the CNS signaling related to dynorphin and dopamine in individuals with this R59Q variation, potentially impacting bipolar disorder pathophysiology.

Cognitive impairment in patients with bipolar disorder alone versus those with bipolar disorder comorbid with borderline personality disorder

BACKGROUND

Bipolar disorder (BD) is a severe mental illness. BD often coexists with borderline personality disorders, making the condition more complex.

AIM

To explore the differences in cognitive impairment between patients with BD and those with BD comorbid with borderline personality disorder.

METHODS

Eighty patients with BD and comorbid borderline personality disorder and 80 patients with BD alone were included in groups A and B, respectively, and 80 healthy volunteers were included as controls. Cognitive function in each group was evaluated using the Chinese version of the repeatable battery for the assessment of neuropsychological status (RBANS), the Stroop color-word test, and the Wechsler intelligence scale-revised (WAIS-RC).

RESULTS

The indices of the RBANS, Stroop color-word test, and WAIS-RC in groups A and B were significantly lower than those of the control group (P < 0.05). Group A had significantly longer Stroop color-word test times for single-character, single-color, double-character, and double-color, lower scores of immediate memory, visual breadth, verbal function dimensions and total score of the RBANS, as well as lower scores of verbal IQ, performance IQ, and overall IQ of the WAIS-RC compared with group B (P < 0.05). Compared to group B, group A exhibited significantly longer single-character time, single-color time, double-character time, and double-color time in the Stroop color-word test (P < 0.05).

CONCLUSION

The cognitive function of patients with BD complicated with borderline personality disorder is lower than that of patients with BD.

Impact of Serotonin Deficiency on Circadian Dopaminergic Rhythms

Physiology and behavior are structured temporally to anticipate daily cycles of light and dark, ensuring fitness and survival. Neuromodulatory systems in the brain-including those involving serotonin and dopamine-exhibit daily oscillations in neural activity and help shape circadian rhythms. Disrupted neuromodulation can cause circadian abnormalities that are thought to underlie several neuropsychiatric disorders, including bipolar mania and schizophrenia, for which a mechanistic understanding is still lacking. Here, we show that genetically depleting serotonin in Tph2 knockout mice promotes manic-like behaviors and disrupts daily oscillations of the dopamine biosynthetic enzyme tyrosine hydroxylase (TH) in midbrain dopaminergic nuclei. Specifically, while TH mRNA and protein levels in the Substantia Nigra (SN) and Ventral Tegmental Area (VTA) of wild-type mice doubled between the light and dark phase, TH levels were high throughout the day in Tph2 knockout mice, suggesting a hyperdopaminergic state. Analysis of TH expression in striatal terminal fields also showed blunted rhythms. Additionally, we found low abundance and blunted rhythmicity of the neuropeptide cholecystokinin (Cck) in the VTA of knockout mice, a neuropeptide whose downregulation has been implicated in manic-like states in both rodents and humans. Altogether, our results point to a previously unappreciated serotonergic control of circadian dopamine signaling and propose serotonergic dysfunction as an upstream mechanism underlying dopaminergic deregulation and ultimately maladaptive behaviors.

Study on the Correlation between Hcy and Hs-CRP Levels and Cognitive Function in Patients with Bipolar Disorder and Borderline Personality Disorder

OBJECTIVE

This study aims to explore the correlation and clinical significance of homocysteine and high-sensitivity C-reactive protein levels with cognitive function in patients with bipolar disorder (BD) and borderline personality disorder (BPD).

METHODS

Patients with BD admitted to our hospital from January 2022 to December 2022 were chosen retrospectively. BPD patients were categorized into comorbidity groups, while those without BPD were assigned to non-comorbidity groups, each consisting of 60 cases. Enzyme-linked immunosorbent assay (ELISA) was utilized to assess serum levels of homocysteine (Hcy) and high-sensitivity C-reactive protein (hs-CRP) in both patient groups. Clinical symptoms were evaluated by the Hamilton Depression Rating Scale (HAMD) and the Young Mania Rating Scale (YMRS). Cognitive function was evaluated and compared using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Pearson correlation analysis was performed on the correlation between patients' serum Hcy and hs-CRP levels and HAMD, YMRS, and RBANS scores.

RESULTS

In the comorbidity group, patients exhibited significantly elevated serum Hcy and hs-CRP levels compared to the non-comorbidity group (p < 0.05). Patients in the comorbidity group displayed higher HAMD and YMRS scores than those in the non-comorbidity group (p < 0.05). Additionally, attention, speech, visual span, immediate memory, and delayed memory in the comorbidity group were notably lower than in the non-comorbidity group (p < 0.05). The speech, visual span, and immediate memory of RBANS in bipolar depressive patients with comorbid BPD were lower than those in bipolar depressive patients without comorbid BPD (p < 0.05), the speech of RBANS in bipolar manic patients with comorbid BPD was lower than those in bipolar manic patients without comorbid BPD (p < 0.05). Pearson correlation analysis showed that the expression of Hcy and hs-CRP in the comorbid group was positively correlated with HAMD and YMRS scores, and negatively correlated with attention, speech, visual span, immediate memory, and delayed memory, and these differences were statistically significant (p < 0.05).

CONCLUSION

High serum Hcy and hs-CRP expression levels may regulate inflammatory responses, aggravating cognitive impairment in patients with BD and BPD. Serum Hcy and hs-CRP expression levels are significantly related to cognitive dysfunction. They are expected to guide the prevention and treatment of BD comorbid BPD patients.