Circulating Brain-Derived Neurotrophic Factor, Antioxidant Enzymes Activities, and Mitochondrial DNA in Bipolar Disorder: An Exploratory Report

Exploring neuroadaptive cellular pathways in chronic morphine exposure: An in-vitro analysis of cabergoline and Mdivi-1 co-treatment effects on the autophagy-apoptosis axis

The complex impacts of prolonged morphine exposure continue to be a significant focus in the expanding area of addiction studies. This research investigates the effectiveness of a combined treatment using Cabergoline and Mdivi-1 to counteract the neuroadaptive changes caused by in vitro morphine treatment. The impact of Methadone, Cabergoline, and a combination of Cabergoline and Mdivi-1 on the cellular and molecular responses associated with Morphine-induced changes was studied in human Neuroblastoma (SK-N-MC) and Glioblastoma (U87-MG) cell lines that were exposed to prolong Morphine treatment. Cabergoline and Mdivi-1 combined treatment effectively influenced the molecular alterations associated with neuroadaptation in chronic morphine-exposed neural cells. This combination therapy normalized autophagy and reduced oxidative stress by enhancing total-antioxidant capacity, mitigating apoptosis, restoring BDNF expression, and balancing apoptotic elements. Our research outlines morphine's dual role in modulating mitochondrial dynamics via the dysregulation of the autophagy-apoptosis axis. This emphasizes the significant involvement of DRP1 activity in neurological adaptation processes, as well as disturbances in the dopaminergic pathway during in vitro chronic exposure to morphine in neural cells. This study proposes a novel approach by recommending the potential effectiveness of combining Cabergoline and Mdivi-1 to modulate the neuroadaptations caused by morphine. Additionally, we identified BDNF and PCNA in neural cells as potential neuroprotective markers for assessing the effectiveness of drugs against opioid toxicity, emphasizing the need for further validation. The study uncovers diverse effects observed in pretreated morphine glioblastoma cells under treatment with Cabergoline and methadone. This highlights the potential for new treatments in the DRD2 pathway and underscores the importance of investigating the interplay between autophagy and apoptosis to advance research in managing cancer-related pain. The study necessitates an in-depth investigation into the relationship between autophagy and apoptosis, with a specific emphasis on protein interactions and the dynamics of cell signaling.

Sex-dependent effects of the uncompetitive N-methyl-D-aspartate receptor antagonist REL-1017 in G93A-SOD1 amyotrophic lateral sclerosis mice

Introduction

The pathogenesis of amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disease caused by the demise of motor neurons has been linked to excitotoxicity caused by excessive calcium influx via N-methyl-D-aspartate receptors (NMDARs), suggesting that uncompetitive NMDAR antagonism could be a strategy to attenuate motor neuron degeneration. REL-1017, the dextro-isomer of racemic methadone, is a low-affinity uncompetitive NMDAR antagonist. Importantly, in humans REL-1017 has shown excellent tolerability in clinical trials for major depression.

Methods

Here, we tested if REL-1017 improves the disease phenotypes in the G93A SOD1 mouse, a well-established model of familial ALS, by examining survival and motor functions, as well as the expression of genes and proteins involved in neuroplasticity.

Results

We found a sex-dependent effect of REL-1017 in G93A SOD1 mice. A delay of ALS symptom onset, assessed as 10%-decrease of body weight (p < 0.01 vs. control untreated mice) and an extension of lifespan (p < 0.001 vs. control untreated mice) was observed in male G93A SOD1 mice. Female G93A SOD1 mice treated with REL-1017 showed an improvement of muscle strength (p < 0.01 vs. control untreated mice). Both males and females treated with REL-1017 showed a decrease in hind limb clasping. Sex-dependent effects of REL-1017 were also detected in molecular markers of neuronal plasticity (PSD95 and SYN1) in the spinal cord and in the GluN1 NMDAR subunit in quadricep muscles.

Conclusion

In conclusion, this study provides preclinical in vivo evidence supporting the clinical evaluation of REL-1017 in ALS.

Centella asiatica extract ameliorates deoxygenation-induced neurological dysfunction in zebrafish larvae

Background

Oxygen deprivation (OD) is a critical condition that can lead to brain damage and even death. Current hypoxia management approaches are limited in effectiveness. Centella asiatica (CA), known for its neuroprotective properties, offers a potential alternative for OD treatment.

Aims

This study aims to investigate the neuroprotective effects of CA on the expression of brain-derived neurotrophic factor (BDNF) and vesicular glutamate transporter 1 (VGLUT1) in zebrafish larvae under oxygen-deficient conditions.

Methods

Zebrafish embryos were subjected to low oxygen levels (1.5 mg/l) 0-2 hours post-fertilization (hpf) until 3 days post-fertilization (dpf), simulating the early stages of OD. Subsequent treatment involved varying concentrations of CA (1.25-5 µg/ml) up to 9 days post-fertilization. The expression levels of BDNF and VGLUT1 were measured using PCR methods. Statistical analysis was conducted using a two-way analysis of variance to evaluate the impact of CA on the expression of BDNF and VGLUT1 in zebrafish larvae aged 3 and 9 dpf in oxygen-deprived conditions.

Results

CA significantly influenced the expression of BDNF and VGLUT1 under OD (p < 0.001). An increase in BDNF expression (p < 0.001) and a decrease in VGLUT1 (p < 0.01) were observed in zebrafish larvae experiencing OD and treated with CA. There was no significant difference in BDNF and VGLUT1 expression across age variations in zebrafish larvae at 3 dpf and 9 dpf in the treatment groups (p > 0.05). CA concentration of 2.5 µg/ml effectively enhanced BDNF and reduced VGLUT1 in 3-9 dpf zebrafish larvae.

Conclusion

CA demonstrates potential as a neuroprotective agent, modulating increased BDNF expression and reduced VGLUT1 under OD conditions. These findings lay a foundation for further research in developing therapies for oxygen deficiency.

The emerging neuroimmune hypothesis of bipolar disorder: An updated overview of neuroimmune and microglial findings

Bipolar disorder (BD) is a severe and multifactorial disease, with onset usually in young adulthood, which follows a progressive course throughout life. Replicated epidemiological studies have suggested inflammatory mechanisms and neuroimmune risk factors as primary contributors to the onset and development of BD. While not all patients display overt markers of inflammation, significant evidence suggests that aberrant immune signaling contributes to all stages of the disease and seems to be mood phase dependent, likely explaining the heterogeneity of findings observed in this population. As the brain's immune cells, microglia orchestrate the brain's immune response and play a critical role in maintaining the brain's health across the lifespan. Microglia are also highly sensitive to environmental changes and respond to physiological and pathological events by adapting their functions, structure, and molecular expression. Recently, it has been highlighted that instead of a single population of cells, microglia comprise a heterogeneous community with specialized states adjusted according to the local molecular cues and intercellular interactions. Early evidence has highlighted the contribution of microglia to BD neuropathology, notably for severe outcomes, such as suicidality. However, the roles and diversity of microglial states in this disease are still largely undermined. This review brings an updated overview of current literature on the contribution of neuroimmune risk factors for the onset and progression of BD, the most prominent neuroimmune abnormalities (including biomarker, neuroimaging, ex vivo studies) and the most recent findings of microglial involvement in BD neuropathology. Combining these different shreds of evidence, we aim to propose a unifying hypothesis for BD pathophysiology centered on neuroimmune abnormalities and microglia. Also, we highlight the urgent need to apply novel multi-system biology approaches to characterize the diversity of microglial states and functions involved in this enigmatic disorder, which can open bright perspectives for novel biomarkers and therapeutic discoveries.

Mitochondrial DNA oxidation, methylation, and copy number alterations in major and bipolar depression

Background

Mood disorders are common disabling psychiatric disorders caused by both genetic and environmental factors. Mitochondrial DNA (mtDNA) modifications and epigenetics are promising areas of research in depression since mitochondrial dysfunction has been associated with depression. In this study we aimed to investigate the mtDNA changes in depressive disorder (MDD) and bipolar disorder (BD).

Methods

Displacement loop methylation (D-loop-met), relative mtDNA copy number (mtDNA-cn) and mtDNA oxidation (mtDNA-oxi) were investigated in DNA samples of individuals with MDD (n = 34), BD (n = 23), and healthy controls (HC; n = 40) using the Real-Time Polymerase Chain Reaction (RT-PCR). Blood samples were obtained from a subset of individuals with MDD (n = 15) during a depressive episode (baseline) and after remission (8th week).

Results

The study groups exhibited significant differences in D-loop-met (p = 0.020), while relative mtDNA-cn and mtDNA-oxi showed comparable results. During the remission phase (8th week), there were lower levels of relative mtDNA-cn (Z = -2.783, p = 0.005) and D-loop-met (Z = -3.180, p = 0.001) compared to the acute MDD baseline, with no significant change in mtDNA-oxi levels (Z = -1.193, p = 0.233).

Conclusion

Our findings indicate significantly increased D-loop methylation in MDD compared to BD and HCs, suggesting distinct mtDNA modifications in these conditions. Moreover, the observed alterations in relative mtDNA-cn and D-loop-met during remission suggest a potential role of mtDNA alterations in the pathophysiology of MDD. Future studies may provide valuable insights into the dynamics of mtDNA modifications in both disorders and their response to treatment.

Therapeutic Interventions to Mitigate Mitochondrial Dysfunction and Oxidative Stress–Induced Damage in Patients with Bipolar Disorder

Bipolar disorder (BD) is characterized by mood changes, including recurrent manic, hypomanic, and depressive episodes, which may involve mixed symptoms. Despite the progress in neurobiological research, the pathophysiology of BD has not been extensively described to date. Progress in the understanding of the neurobiology driving BD could help facilitate the discovery of therapeutic targets and biomarkers for its early detection. Oxidative stress (OS), which damages biomolecules and causes mitochondrial and dopamine system dysfunctions, is a persistent finding in patients with BD. Inflammation and immune dysfunction might also play a role in BD pathophysiology. Specific nutrient supplements (nutraceuticals) may target neurobiological pathways suggested to be perturbed in BD, such as inflammation, mitochondrial dysfunction, and OS. Consequently, nutraceuticals may be used in the adjunctive treatment of BD. This paper summarizes the possible roles of OS, mitochondrial dysfunction, and immune system dysregulation in the onset of BD. It then discusses OS-mitigating strategies that may serve as therapeutic interventions for BD. It also analyzes the relationship between diet and BD as well as the use of nutritional interventions in the treatment of BD. In addition, it addresses the use of lithium therapy; novel antipsychotic agents, including clozapine, olanzapine, risperidone, cariprazine, and quetiapine; and anti-inflammatory agents to treat BD. Furthermore, it reviews the efficacy of the most used therapies for BD, such as cognitive–behavioral therapy, bright light therapy, imagery-focused cognitive therapy, and electroconvulsive therapy. A better understanding of the roles of OS, mitochondrial dysfunction, and inflammation in the pathogenesis of bipolar disorder, along with a stronger elucidation of the therapeutic functions of antioxidants, antipsychotics, anti-inflammatory agents, lithium therapy, and light therapies, may lead to improved strategies for the treatment and prevention of bipolar disorder.

Endovascular Stem Cell Therapy Post Stroke Rescues Neurons from Endoplasmic Reticulum Stress-Induced Apoptosis by Modulating Brain-Derived Neurotrophic Factor/Tropomyosin Receptor Kinase B Signaling

Ischemic stroke is devastating, with serious long-term disabilities affecting millions of people worldwide. Growing evidence has shown that mesenchymal stem cells (MSCs) administration after stroke provides neuroprotection and enhances the quality of life in stroke patients. Previous studies from our lab have shown that 1 × 10⁵ MSCs administered intra-arterially (IA) at 6 h post stroke provide neuroprotection through the modulation of inflammasome and calcineurin signaling. Ischemic stroke induces endoplasmic reticulum (ER) stress, which exacerbates the pathology. The current study intends to understand the involvement of brain-derived neurotrophic factor/tropomyosin receptor kinase B (BDNF/TrkB) signaling in preventing apoptosis induced by ER stress post stroke following IA MSCs administration. Ischemic stroke was induced in ovariectomized female Sprague Dawley rats. The MSCs were administered IA, and animals were sacrificed at 24 h post stroke. Infarct area, neurological deficit score, motor coordination, and biochemical parameters were evaluated. The expression of various genes and proteins was assessed. An inhibition study was also carried out to confirm the involvement of BDNF/TrkB signaling in ER stress-induced apoptosis. IA-administered MSCs improved functional outcomes, reduced infarct area, increased neuronal survival, and normalized biochemical parameters. mRNA and protein expression of ER stress markers were reduced, while those of BDNF and TrkB were increased. Reduction in ER stress-mediated apoptosis was also observed. The present study shows that IA MSCs administration post stroke provides neuroprotection and can modulate ER stress-mediated apoptosis via the BDNF/TrkB signaling pathway.

Molecular Biomarkers of Electroconvulsive Therapy Effects and Clinical Response: Understanding the Present to Shape the Future

Electroconvulsive therapy (ECT) represents an effective intervention for treatment-resistant depression (TRD). One priority of this research field is the clarification of ECT response mechanisms and the identification of biomarkers predicting its outcomes. We propose an overview of the molecular studies on ECT, concerning its course and outcome prediction, including also animal studies on electroconvulsive seizures (ECS), an experimental analogue of ECT. Most of these investigations underlie biological systems related to major depressive disorder (MDD), such as the neurotrophic and inflammatory/immune ones, indicating effects of ECT on these processes. Studies about neurotrophins, like the brain-derived neurotrophic factor (BDNF) and the vascular endothelial growth factor (VEGF), have shown evidence concerning ECT neurotrophic effects. The inflammatory/immune system has also been studied, suggesting an acute stress reaction following an ECT session. However, at the end of the treatment, ECT produces a reduction in inflammatory-associated biomarkers such as cortisol, TNF-alpha and interleukin 6. Other biological systems, including the monoaminergic and the endocrine, have been sparsely investigated. Despite some promising results, limitations exist. Most of the studies are concentrated on one or few markers and many studies are relatively old, with small sample sizes and methodological biases. Expression studies on gene transcripts and microRNAs are rare and genetic studies are sparse. To date, no conclusive evidence regarding ECT molecular markers has been reached; however, the future may be just around the corner.

The Role of Mitonuclear Incompatibility in Bipolar Disorder Susceptibility and Resilience Against Environmental Stressors

It has been postulated that mitochondrial dysfunction has a significant role in the underlying pathophysiology of bipolar disorder (BD). Mitochondrial functioning plays an important role in regulating synaptic transmission, brain function, and cognition. Neuronal activity is energy dependent and neurons are particularly sensitive to changes in bioenergetic fluctuations, suggesting that mitochondria regulate fundamental aspects of brain function. Vigorous evidence supports the role of mitochondrial dysfunction in the etiology of BD, including dysregulated oxidative phosphorylation, general decrease of energy, altered brain bioenergetics, co-morbidity with mitochondrial disorders, and association with genetic variants in mitochondrial DNA (mtDNA) or nuclear-encoded mitochondrial genes. Despite these advances, the underlying etiology of mitochondrial dysfunction in BD is unclear. A plausible evolutionary explanation is that mitochondrial-nuclear (mitonuclear) incompatibility leads to a desynchronization of machinery required for efficient electron transport and cellular energy production. Approximately 1,200 genes, encoded from both nuclear and mitochondrial genomes, are essential for mitochondrial function. Studies suggest that mitochondrial and nuclear genomes co-evolve, and the coordinated expression of these interacting gene products are essential for optimal organism function. Incompatibilities between mtDNA and nuclear-encoded mitochondrial genes results in inefficiency in electron flow down the respiratory chain, differential oxidative phosphorylation efficiency, increased release of free radicals, altered intracellular Ca²⁺ signaling, and reduction of catalytic sites and ATP production. This review explores the role of mitonuclear incompatibility in BD susceptibility and resilience against environmental stressors.

Concepts of Neuroinflammation and Their Relationship With Impaired Mitochondrial Functions in Bipolar Disorder

Bipolar disorder (BD) is a chronic psychiatric disease, characterized by frequent behavioral episodes of depression and mania, and neurologically by dysregulated neurotransmission, neuroplasticity, growth factor signaling, and metabolism, as well as oxidative stress, and neuronal apoptosis, contributing to chronic neuroinflammation. These abnormalities result from complex interactions between multiple susceptibility genes and environmental factors such as stress. The neurocellular abnormalities of BD can result in gross morphological changes, such as reduced prefrontal and hippocampal volume, and circuit reorganization resulting in cognitive and emotional deficits. The term "neuroprogression" is used to denote the progressive changes from early to late stages, as BD severity and loss of treatment response correlate with the number of past episodes. In addition to circuit and cellular abnormalities, BD is associated with dysfunctional mitochondria, leading to severe metabolic disruption in high energy-demanding neurons and glia. Indeed, mitochondrial dysfunction involving electron transport chain (ETC) disruption is considered the primary cause of chronic oxidative stress in BD. The ensuing damage to membrane lipids, proteins, and DNA further perpetuates oxidative stress and neuroinflammation, creating a perpetuating pathogenic cycle. A deeper understanding of BD pathophysiology and identification of associated biomarkers of neuroinflammation are needed to facilitate early diagnosis and treatment of this debilitating disorder.