The Association Between Vascular Inflammation and Depressive Disorder. Causality, Biomarkers and Targeted Treatment

Breakdown of the blood-brain barrier in depressed mice induced by chronic unpredictable mild stress

BACKGROUND

Recent studies have suggested potential impairment of the blood-brain barrier (BBB) in depression. However, due to the limited research and variability in animal models, further investigation using diverse and stable models is necessary.

METHODS

A male mouse model of depression was established using the chronic unpredictable mild stress (CUMS) protocol. Following model establishment, depression-like behaviors were assessed using the sucrose preference test, tail suspension test, and forced swimming test. Morphological changes in the hippocampus were examined through hematoxylin-eosin staining. BBB permeability was evaluated using the Evans blue leakage test, fluorescein sodium (NaF) leakage test, and serum S100B content assessment. Gene and protein expression levels of BBB-related proteins in the hippocampus were determined via real-time PCR, western blotting, and immunofluorescence assays.

RESULTS

CUMS exposure induced depression-like behaviors, including reduced body weight gain, diminished sucrose preference, and prolonged immobility in both the tail suspension test and forced swimming test. While no significant pathological changes were observed in the hippocampus of either group, increased BBB permeability was noted in the CUMS group, as evidenced by enhanced NaF leakage into the brain parenchyma and elevated serum S100B levels. Gene expression analysis revealed downregulation of angiogenesis-related genes and tight junction proteins in the CUMS group. Additionally, protein levels of tight junction proteins Claudin-5 and ZO-1 were lower in the CUMS group compared to controls.

LIMITATIONS

This study is limited to a male mouse model, and the BBB in females is worth exploring in the future.

CONCLUSIONS

Increased BBB permeability and decreased expression of tight junction proteins Claudin5 and ZO-1 were observed in mice with CUMS-induced depression.

Microglia Sing the Prelude of Neuroinflammation-Associated Depression

Major depressive disorder (MDD) is a psychiatric condition characterized by sadness and anhedonia and is closely linked to chronic low-grade neuroinflammation, which is primarily induced by microglia. Nonetheless, the mechanisms by which microglia elicit depressive symptoms remain uncertain. This review focuses on the mechanism linking microglia and depression encompassing the breakdown of the blood-brain barrier, the hypothalamic-pituitary-adrenal axis, the gut-brain axis, the vagus and sympathetic nervous systems, and the susceptibility influenced by epigenetic modifications on microglia. These pathways may lead to the alterations of microglia in cytokine levels, as well as increased oxidative stress. Simultaneously, many antidepressant treatments can alter the immune phenotype of microglia, while anti-inflammatory treatments can also have antidepressant effects. This framework linking microglia, neuroinflammation, and depression could serve as a reference for targeting microglia to treat depression.

Integrating digital gait data with metabolomics and clinical data to predict outcomes in Parkinson's disease

Parkinson's disease (PD) presents diverse symptoms and comorbidities, complicating its diagnosis and management. The primary objective of this cross-sectional, monocentric study was to assess digital gait sensor data's utility for monitoring and diagnosis of motor and gait impairment in PD. As a secondary objective, for the more challenging tasks of detecting comorbidities, non-motor outcomes, and disease progression subgroups, we evaluated for the first time the integration of digital markers with metabolomics and clinical data. Using shoe-attached digital sensors, we collected gait measurements from 162 patients and 129 controls in a single visit. Machine learning models showed significant diagnostic power, with AUC scores of 83-92% for PD vs. control and up to 75% for motor severity classification. Integrating gait data with metabolomics and clinical data improved predictions for challenging-to-detect comorbidities such as hallucinations. Overall, this approach using digital biomarkers and multimodal data integration can assist in objective disease monitoring, diagnosis, and comorbidity detection.

Depressive Symptoms are Associated With C-Reactive Protein in Older Adults With Obesity

OBJECTIVES

To test the hypothesis that depressive symptoms vary with high-sensitivity C-reactive protein (hs-CRP), among older adults with obesity.

METHODS

This was a cross-sectional, secondary analysis of baseline data from two related lifestyle intervention trials. The study sample comprises 148 consecutively recruited, community-dwelling older adults (age >=65 years) without severe psychiatric illness and with body mass index >=30 kg/m2. Logarithmically transformed GDS was analyzed as the dependent variable. Independent variables included log-transformed hs-CRP and covariates: sex, age, and concurrent use of antidepressant medication at baseline. An additional analysis was performed using binary conversion of the GDS scores, wherein a cutoff score of 5 was considered positive for depressive symptoms.

RESULTS

Sample mean GDS score was 2.7 (SD 3.0, range 0 - 14). A significant multivariate model of GDS scores (R2 = .089, F = 3.5, P = .010) revealed log-transformed hs-CRP (P = .017) and male sex (P = .012) as associated with depressive symptoms. Supplemental analysis demonstrated associations between depressive symptoms and log-transformed hs-CRP (OR 2.17, P = .001) and between depressive symptoms and male sex (OR 3.78, P = .013). Univariate logistic regression found hs-CRP to be associated with depressive symptoms.

CONCLUSIONS

In older adults with obese BMI, male sex and higher hs-CRP are associated with depression, even in a group with relatively minimal depressive symptoms. Hs-CRP may offer clinical utility as a biomarker for depression among older adults with obese BMI, even among those with non-severe psychiatric symptomatology.

Omega-3 PUFAs' efficacy in the therapy of coronary artery disease combined with anxiety or depression: a meta-analysis

Objective

The evidence demonstrates that omega-3 polyunsaturated fatty acids (omega-3 PUFAs) protect the cardiovascular system and alleviate anxious or depressive situations. We conducted a meta-analysis to evaluate the effectiveness of omega-3 PUFAs in the treatment of anxiety or depressive states in patients with coronary artery disease.

Methods

This meta-analysis analyzed data from randomized controlled trials to determine the efficacy of omega-3 PUFAs alone or in combination with conventional psychotropic medications in coronary artery disease patients suffering from anxiety or depression. Primary outcomes included changes in depression scores, the Beck Anxiety Inventory (BAI) scores, and the omega-3 index.

Results

Included were 6 trials involving 2,570 participants. Compared to controls,omega-3 PUFAs did not improve depression or anxiety {depression: [SMD=0.09 (95% CI: -0.07, 0.26)], anxiety [BAI: SMD=0.07 (95% CI: -0.17, 0.32)]}; For the results of the subgroup analyses, analyzed by different types of depression scales, four studies used the HAMD scale [SMD=0.19 (95% CI: -0.20, 0.58)]; 5 studies used the BDI-II scale [SMD=0.01 (95% CI: -0.07, 0.09)], all of which indicated no decrease in depression scale scores; analyzed by different types of intervention, 3 studies used the omega-3 PUFAs group [SMD=0.24 (95% CI: -0.26, 0.74)]; 2 studies used sertraline + omega-3 PUFAs [SMD=-0.08 (95% CI: -0.46, 0.31)], and the omega-3 index was elevated [SMD=1.33 (95% CI: 0.18, 2.49)], suggesting that the body's omega-3 content was indeed replenished but did not change the patient's depressive state; analyzed by different courses of therapy, a 10-week course of therapy [SMD=0.02 (95% CI: -0.23, 0.26)] and a 12-week course of therapy [SMD=0.40 (95% CI: -0.40, 1.20)] both resulted in a lack of improvement in depressive symptoms.

Conclusion

According to the available evidence, omega-3 PUFAs do not alleviate anxiety or depression in coronary artery disease patients.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023391259.

Impaired brain equanimity and neurogenesis in the diet-induced overweight mouse: a preventive role by syringic acid treatment

OBJECTIVES

In this study mice were fed a high-fat diet for 12 weeks to establish diet-induced obesity and syringic acid (SA) was assessed for anti-obese, neuroprotective, and neurogenesis.

METHOD

Animals were given HFD for 12 weeks to measure metabolic characteristics and then put through the Barns-maze and T-maze tests to measure memory. Additionally, the physiology of the blood-brain barrier, oxidative stress parameters, the expression of inflammatory genes, neurogenesis, and histopathology was evaluated in the brain.

RESULT

DIO raised body weight, BMI, and other metabolic parameters after 12 weeks of overfeeding. A reduced spontaneous alternation in behavior (working memory, reference memory, and total time to complete a task), decreased enzymatic and non-enzymatic antioxidants, oxidative biomarkers, increased neurogenesis, and impaired blood-brain barrier were all seen in DIO mice. SA (50 mg/kg) treatment of DIO mice (4 weeks after 8 weeks of HFD feeding) reduced diet-induced changes in lipid parameters associated with obesity, hepatological parameters, memory, blood-brain barrier, oxidative stress, neuroinflammation, and neurogenesis. SA also reduced the impact of malondialdehyde and enhanced the effects of antioxidants such as glutathione, superoxide dismutase (SOD), and total thiol (MDA). Syringic acid improved neurogenesis, cognition, and the blood-brain barrier while reducing neurodegeneration in the hippocampal area.

DISCUSSION

According to the results of the study, syringic acid therapy prevented neurodegeneration, oxidative stress, DIO, and memory loss. Syringic acid administration may be a useful treatment for obesity, memory loss, and neurogenesis, but more research and clinical testing is needed.

The Relationship between Depressive Symptoms, Quality of Life and miRNAs 8 Years after Bariatric Surgery

(1) Background: There are conflicting results on whether weight loss after bariatric surgery (BS) might be associated with quality of life (QoL)/depressive symptomatology. We aim to determine whether BS outcomes are associated with QoL/depressive symptomatology in studied patients at the 8-year follow-up after BS, as well as their relationship with different serum proteins and miRNAs. (2) Methods: A total of 53 patients with class III obesity who underwent BS, and then classified into "good responders" and "non-responders" depending on the percentage of excess weight lost (%EWL) 8 years after BS (%EWL ≥ 50% and %EWL < 50%, respectively), were included. Basal serum miRNAs and different proteins were analysed, and patients completed tests to evaluate QoL/depressive symptomatology at 8 years after BS. (3) Results: The good responders group showed higher scores on SF-36 scales of physical functioning, role functioning-physical, role functioning-emotional, body pain and global general health compared with the non-responders. The expression of hsa-miR-101-3p, hsa-miR-15a-5p, hsa-miR-29c-3p, hsa-miR-144-3p and hsa-miR-19b-3p were lower in non-responders. Hsa-miR-19b-3p was the variable associated with the response to BS in a logistic regression model. (4) Conclusions: The mental health of patients after BS is limited by the success of the intervention. In addition, the expression of basal serum miRNAs related to depression/anxiety could predict the success of BS.

The heterogeneity of late-life depression and its pathobiology: a brain network dysfunction disorder

Depression is frequent in older individuals and is often associated with cognitive impairment and increasing risk of subsequent dementia. Late-life depression (LLD) has a negative impact on quality of life, yet the underlying pathobiology is still poorly understood. It is characterized by considerable heterogeneity in clinical manifestation, genetics, brain morphology, and function. Although its diagnosis is based on standard criteria, due to overlap with other age-related pathologies, the relationship between depression and dementia and the relevant structural and functional cerebral lesions are still controversial. LLD has been related to a variety of pathogenic mechanisms associated with the underlying age-related neurodegenerative and cerebrovascular processes. In addition to biochemical abnormalities, involving serotonergic and GABAergic systems, widespread disturbances of cortico-limbic, cortico-subcortical, and other essential brain networks, with disruption in the topological organization of mood- and cognition-related or other global connections are involved. Most recent lesion mapping has identified an altered network architecture with "depressive circuits" and "resilience tracts", thus confirming that depression is a brain network dysfunction disorder. Further pathogenic mechanisms including neuroinflammation, neuroimmune dysregulation, oxidative stress, neurotrophic and other pathogenic factors, such as β-amyloid (and tau) deposition are in discussion. Antidepressant therapies induce various changes in brain structure and function. Better insights into the complex pathobiology of LLD and new biomarkers will allow earlier and better diagnosis of this frequent and disabling psychopathological disorder, and further elucidation of its complex pathobiological basis is warranted in order to provide better prevention and treatment of depression in older individuals.

Inhibition of Microglial GSK3β Activity Is Common to Different Kinds of Antidepressants: A Proposal for an In Vitro Screen to Detect Novel Antidepressant Principles

Depression is a major public health concern. Unfortunately, the present antidepressants often are insufficiently effective, whilst the discovery of more effective antidepressants has been extremely sluggish. The objective of this review was to combine the literature on depression with the pharmacology of antidepressant compounds, in order to formulate a conceivable pathophysiological process, allowing proposals how to accelerate the discovery process. Risk factors for depression initiate an infection-like inflammation in the brain that involves activation microglial Toll-like receptors and glycogen synthase kinase-3β (GSK3β). GSK3β activity alters the balance between two competing transcription factors, the pro-inflammatory/pro-oxidative transcription factor NFκB and the neuroprotective, anti-inflammatory and anti-oxidative transcription factor NRF2. The antidepressant activity of tricyclic antidepressants is assumed to involve activation of GS-coupled microglial receptors, raising intracellular cAMP levels and activation of protein kinase A (PKA). PKA and similar kinases inhibit the enzyme activity of GSK3β. Experimental antidepressant principles, including cannabinoid receptor-2 activation, opioid μ receptor agonists, 5HT2 agonists, valproate, ketamine and electrical stimulation of the Vagus nerve, all activate microglial pathways that result in GSK3β-inhibition. An in vitro screen for NRF2-activation in microglial cells with TLR-activated GSK3β activity, might therefore lead to the detection of totally novel antidepressant principles with, hopefully, an improved therapeutic efficacy.

Epidemiology and health impact of diabetes in France

OBJECTIVES

Diabetes is a growing health concern. An update on epidemiology and health outcomes is mandatory to devise strategies to alleviate the burden of diabetes. The objective of this study was to assess the prevalence of diabetes and associated complications in France in 2017.

METHODS

Demographics and healthcare data from a representative permanent secondary database were analyzed. Patients with at least 2 national health insurance payments for anti-diabetic drugs in 2017 were selected, with the index date set to the last payment date. Patients were grouped as diabetes treated with insulin only (DTi), diabetes treated with anti-diabetic drugs other than only insulin (DT2) or gestational diabetes. Comorbidities, diabetes-related complications and hospital admissions, healthcare consumption and medical follow-up were extracted for a 5- or 2-year period prior to the index date and summarized using descriptive statistics.

RESULTS

Overal, 29,288 patients were included in the study population: 1964 (6.7%) were categorized as DTi and 27,243 (93.0%) as DT2. Patients with gestational diabetes (81 [0.3%]) are not further described here. Prevalence was estimated at 4.9%. For DT2, marked geographic disparities were observed, with prevalence being highest in the northeast France. Diabetes-related complications were more frequent in DTi than in DT2 over a 5-year period (52.2% vs 34.7%). Diabetes-related admissions were also more common in DTi than in DT2 over a 2-year period (29.8% vs 16.9%). In the DT2 category, another antidiabetic drug was added during the 3 months prior to the index date in 16.5% of cases overall and in 25% of patients with recent hospital admission or diabetes-related complications. Although more than 80% of patients in the DTi and DT2 categories had at least 1 healthcare consultation during 2 years prior to the index date, only 10% to 20% of patients complied with guidelines for all 5 recommended examinations.

CONCLUSIONS

Prevalence of diabetes is high in the French population, while compliance with recommended healthcare consultations falls short of the 80% goal set by regulations. New strategies are mandatory in order to reduce the burden of diabetes-related complications and admissions, focusing on patient and physician information and education in order to increase proactive treatment adjustment and reduce therapeutic inertia.

The enigma of vascular depression in old age: a critical update

Depression is common in older individuals and is associated with high disability and increased mortality, yet the factors predicting late-life depression (LLD) are poorly understood. The relationship between of depressive disorder, age- and disease-related processes have generated pathogenic hypotheses and provided new treatment options. LLD syndrome is often related to a variety of vascular mechanisms, in particular hypertension, cerebral small vessel disease, white matter lesions, subcortical vascular impairment, and other processes (e.g., inflammation, neuroimmune regulatory dysmechanisms, neurodegenerative changes, amyloid accumulation) that may represent etiological factors by affecting frontolimbic and other neuronal networks predisposing to depression. The "vascular depression" hypothesis suggests that cerebrovascular disease (CVD) and vascular risk factors may predispose, induce or perpetuate geriatric depressive disorders. It is based on the presence of various cerebrovascular risk factors in many patients with LLD, its co-morbidity with cerebrovascular lesions, and the frequent development of depression after stroke. Other findings related to vascular depression are atrophy of the medial temporal cortex or generalized cortical atrophy that are usually associated with cognitive impairment. Other pathogenetic hypotheses of LLD, such as metabolic or inflammatory ones, are briefly discussed. Treatment planning should consider there may be a modest response to antidepressants, but several evidence-based and novel treatment options for LLD exist, such as electroconvulsive therapy, transcranial magnetic stimulation, neurobiology-based psychotherapy, as well as antihypertension and antiinflammatory drugs. However, their effectiveness needs further investigation, and new methodologies for prevention and treatment of depression in older individuals should be developed.

Cerebral derailment after myocardial infarct: mechanisms and effects of the signaling from the ischemic heart to brain

Myocardial infarction (MI) is the leading cause of death among ischemic heart diseases and is associated with several long-term cardiovascular complications, such as angina, re-infarction, arrhythmias, and heart failure. However, MI is frequently accompanied by non-cardiovascular multiple comorbidities, including brain disorders such as stroke, anxiety, depression, and cognitive impairment. Accumulating experimental and clinical evidence suggests a causal relationship between MI and stroke, but the precise underlying mechanisms have not yet been elucidated. Indeed, the risk of stroke remains a current challenge in patients with MI, in spite of the improvement of medical treatment among this patient population has reduced the risk of stroke. In this review, the effects of the signaling from the ischemic heart to the brain, such as neuroinflammation, neuronal apoptosis, and neurogenesis, and the possible actors mediating these effects, such as systemic inflammation, immunoresponse, extracellular vesicles, and microRNAs, are discussed.

Pathomechanisms of Vascular Depression in Older Adults

Depression in older individuals is a common complex mood disorder with high comorbidity of both psychiatric and physical diseases, associated with high disability, cognitive decline, and increased mortality The factors predicting the risk of late-life depression (LLD) are incompletely understood. The reciprocal relationship of depressive disorder and age- and disease-related processes has generated pathogenic hypotheses and provided various treatment options. The heterogeneity of depression complicates research into the underlying pathogenic cascade, and factors involved in LLD considerably differ from those involved in early life depression. Evidence suggests that a variety of vascular mechanisms, in particular cerebral small vessel disease, generalized microvascular, and endothelial dysfunction, as well as metabolic risk factors, including diabetes, and inflammation that may induce subcortical white and gray matter lesions by compromising fronto-limbic and other important neuronal networks, may contribute to the development of LLD. The "vascular depression" hypothesis postulates that cerebrovascular disease or vascular risk factors can predispose, precipitate, and perpetuate geriatric depression syndromes, based on their comorbidity with cerebrovascular lesions and the frequent development of depression after stroke. Vascular burden is associated with cognitive deficits and a specific form of LLD, vascular depression, which is marked by decreased white matter integrity, executive dysfunction, functional disability, and poorer response to antidepressive therapy than major depressive disorder without vascular risk factors. Other pathogenic factors of LLD, such as neurodegeneration or neuroimmune regulatory dysmechanisms, are briefly discussed. Treatment planning should consider a modest response of LLD to antidepressants, while vascular and metabolic factors may provide promising targets for its successful prevention and treatment. However, their effectiveness needs further investigation, and intervention studies are needed to assess which interventions are appropriate and effective in clinical practice.

Endothelial dysfunction in people with depressive disorders: A systematic review and meta-analysis

The study aimed to identify whether people diagnosed with depression have endothelial dysfunction, assessed by the technique of flow-mediated dilation (FMD), when compared to controls without depression. In addition, to verify whether people with depressive symptoms have impaired endothelial function when compared to controls without symptoms. Also to explore the potential moderators of the association between depression and endothelial dysfunction. Systematic review and meta-analysis. We searched PubMed, PsycINFO, Embase and Web of Science, from inception to April 16, 2021, for studies in people with depression and controls evaluating endothelial function through FMD. The primary outcome was the percentage of change in FMD. Comparative random effects meta-analysis, calculating the mean difference (MD) of the FMD between depressed and controls was performed. Potential sources of heterogeneity were explored by meta-regressions and subgroup analyses. The study protocol was registered with PROSPERO (CRD42020192070). Nine studies evaluating 1367 participants (379 depressed and 988 controls) (median age = 39.8 years, 44.9% men) were included. People with depression had lower FMD = -1.48% (95%CI = -2.62 to -0.33). High density lipoprotein (HDL) cholesterol levels moderated the effect (beta = -0.408, 95%CI = -0.776 to -0.040). Differences in FMD were found when assessment was done in the first minute after release of the occlusion, when using occlusion position in distal forearm, and when using occlusion pressure between 250 and 300 mmHg. Those with clinical depression (established by diagnostic instruments) presented the greatest dysfunction. Individuals with depression have a more impaired endothelial dysfunction when compared to controls. HDL cholesterol levels and differences in FMD assessment modalities moderate the difference.

Long-term administration of resveratrol at low doses improves neurocognitive performance as well as cerebral blood flow and modulates the inflammatory pathways in the brain

There is an increasing prevalence of coincident cerebrovascular deficiency and cognitive dysfunction with aging. Increased oxidative stress as well as inflammation that occurs with aging are associated with the impairment of cerebral vascularization. Interestingly, Resveratrol (RSV), a natural phytoalexin, is known to be a strong antioxidant and possesses anti-inflammatory properties. Collectively, these observations strongly suggest that RSV could protect against cerebral vascularization defect and then improves the decline cognitive function associated with aging. In order to test this hypothesis, we investigated the effect of a long-term RSV treatment (1.25 mg/day for 5 months) on cognitive performances of animals that we have allowed to age normally. Then, we further analyzed the gene expression profile and the cerebral blood flow in the brain. By means of novel object recognition (NOR) test, we observed that RSV enhanced NOR performances of aged rats. In addition, RSV enhanced cerebral blood flow during NOR task in aged rats. Using microarrays experiments, we also showed that several pathways related to inflammation and oxidative stress (Eicosanoid signaling, MIF-mediated innate immunity, NF-kB signaling, TNFR2 signaling, IL6 signaling, Production of nitric oxide and ROS) were down-regulated in the brain of RSV treatments rats compared to control rats. In conclusion, these results support that a long-term treatment with RSV improves cognitive performance in the elderly male rat model. This effect is associated with an increase in cerebral blood flow and a decrease in the expression of several pro-inflammatory pathways in the brain.

Disentangling the Molecular Mechanisms of the Antidepressant Activity of Omega-3 Polyunsaturated Fatty Acid: A Comprehensive Review of the Literature

Major depressive disorders (MDDs) are often associated with a deficiency in long-chain omega-3 polyunsaturated fatty acids (ω-3 PUFAs), as well as signs of low-grade inflammation. Epidemiological and dietary studies suggest that a high intake of fish, the major source of ω-3 PUFAs, is associated with lower rates of MDDs. Meta-analyses of randomized placebo-controlled ω-3 PUFAs intervention-trials suggest that primarily eicosapentaenoic acid (EPA), but not docosahexaenoic acid (DHA), is responsible for the proposed antidepressant effect. In this review, we dissect the current biological knowledge on EPA and DHA and their bioactive lipid metabolites to search for a pharmacological explanation of this, to date, unexplained clinical observation. Through enzymatic conversion by cyclooxygenase (COX), lipoxygenase (ALOX), and cytochrome P-450 monooxygenase (CYP), EPA and DHA are metabolized to major anti-inflammatory and pro-resolving lipid mediators. In addition, both ω-3 PUFAs are precursors for endocannabinoids, with known effects on immunomodulation, neuroinflammation, food intake and mood. Finally, both ω-3 PUFAs are crucial for the structure and organization of membranes and lipid rafts. While most biological effects are shared by these two ω-3 PUFAs, some distinct features could be identified: (1) The preferential CYP monooxygenase pathway for EPA and EPA derived eicosanoids; (2) The high CB2 receptor affinities of EPA-derived EPEA and its epoxy-metabolite 17,18-EEQ-EA, while the DHA-derived endocannabinoids lack such receptor affinities; (3) The competition of EPA but not DHA with arachidonic acid (AA) for particular glycerophospholipids. EPA and AA are preferentially incorporated into phosphatidylinositols, while DHA is mainly incorporated into phosphatidyl-ethanolamine, -serine and -choline. We propose that these distinct features may explain the superior antidepressant activity of EPA rich ω-3 PUFAs and that these are potential novel targets for future antidepressant drugs.

Endothelial dysfunction in neuroprogressive disorders-causes and suggested treatments

BACKGROUND

Potential routes whereby systemic inflammation, oxidative stress and mitochondrial dysfunction may drive the development of endothelial dysfunction and atherosclerosis, even in an environment of low cholesterol, are examined.

MAIN TEXT

Key molecular players involved in the regulation of endothelial cell function are described, including PECAM-1, VE-cadherin, VEGFRs, SFK, Rho GEF TRIO, RAC-1, ITAM, SHP-2, MAPK/ERK, STAT-3, NF-κB, PI3K/AKT, eNOS, nitric oxide, miRNAs, KLF-4 and KLF-2. The key roles of platelet activation, xanthene oxidase and myeloperoxidase in the genesis of endothelial cell dysfunction and activation are detailed. The following roles of circulating reactive oxygen species (ROS), reactive nitrogen species and pro-inflammatory cytokines in the development of endothelial cell dysfunction are then described: paracrine signalling by circulating hydrogen peroxide, inhibition of eNOS and increased levels of mitochondrial ROS, including compromised mitochondrial dynamics, loss of calcium ion homeostasis and inactivation of SIRT-1-mediated signalling pathways. Next, loss of cellular redox homeostasis is considered, including further aspects of the roles of hydrogen peroxide signalling, the pathological consequences of elevated NF-κB, compromised S-nitrosylation and the development of hypernitrosylation and increased transcription of atherogenic miRNAs. These molecular aspects are then applied to neuroprogressive disorders by considering the following potential generators of endothelial dysfunction and activation in major depressive disorder, bipolar disorder and schizophrenia: NF-κB; platelet activation; atherogenic miRs; myeloperoxidase; xanthene oxidase and uric acid; and inflammation, oxidative stress, nitrosative stress and mitochondrial dysfunction.

CONCLUSIONS

Finally, on the basis of the above molecular mechanisms, details are given of potential treatment options for mitigating endothelial cell dysfunction and activation in neuroprogressive disorders.