Multiple Immune-Inflammatory and Oxidative and Nitrosative Stress Pathways Explain the Frequent Presence of Depression in Multiple Sclerosis

Apoptosis-induced decline in hippocampal microglia mediates the development of depression-like behaviors in adult mice triggered by unpredictable stress during adolescence

Depression triggered by harmful stress during adolescence is a common problem that can affect mental health. To date, the mechanisms underlying this type of depression remain unclear. One mechanism for the promotion of depression by chronic stress in adulthood is the loss of hippocampal microglia. Since deleterious stress in adolescence also activates microglia, we investigated the dynamic changes of microglia in the hippocampus in mice exposed to chronic unpredictable stress (CUS) in adolescence. Our results showed that 12 days of CUS stimulation in adolescence induced typical depression-like behaviors in adult mice, which were accompanied by a significant decrease and dystrophy of microglia in the dentate gyrus of the hippocampus. Further analysis showed that this decrease in microglia was mediated by the initial response of microglia to unpredictable stress in the dentate gyrus of the hippocampus and their subsequent apoptosis. Blocking the initial response of microglia to unpredictable stress by pretreatment with minocycline was able to prevent apoptosis and microglial decline as well as the development of depression-like behaviors in adult mice induced by adolescent CUS. Moreover, administration of lipopolysaccharide (LPS) or macrophage-colony stimulatory factor (M-CSF), two drugs that reversed microglia decline in the dentate gyrus, ameliorated the depression-like behaviors induced by CUS stimulation in adolescence. These findings reveal a novel mechanism for the development of depression-like behaviors in animals triggered by deleterious stress in adolescence and suggest that reversing microglial decline in the hippocampus may be a hopeful strategy for the treatment of depression triggered by deleterious stress in adolescence.

Depression and anxiety in multiple sclerosis. Review of a fatal combination

Depression and anxiety are the most frequent neuropsychiatric symptoms of multiple sclerosis (MS), an autoimmune-mediated demyelinating neurodegenerative disease. Their prevalence is 25-65% and 20-54%, respectively, often associated with chronic fatigue and cognitive impairment, but usually not correlated with motor and other deficits, suggesting different pathophysiological mechanisms. Both disorders often arise before MS diagnosis, lead to faster disability and impair the quality of life. Risk factors are (young) age, genetic and family history burden. While no specific neuropathological data for depression (and anxiety) in MS are available, modern neuroimaging studies showed bilateral fronto-temporal, subcortical and limbic atrophies, microstructural white matter lesions and disruption of frontoparietal, limbic and neuroendocrine networks. The pathogenesis of both depression and anxiety in MS is related to shared mechanisms including oxidative stress, mitochondrial dysfunction, neuroinflammation and neuroendocrine mechanisms inducing complex functional and structural brain lesions, but they are also influenced by social and other factors. Unfortunately, MS patients with anxiety, major depression or suicidal thoughts are often underassessed and undertreated. Current treatment, in addition to antidepressant therapy include transcranial magnetic stimulation, cognitive, relaxation, dietary and other healthcare measures that must be individualized. The present state-of- the-art review is based on systematic analysis of PubMed, Google Scholar and Cochrane Library until May 2024, with focus on the prevalence, clinical manifestation, neuroimaging data, immune mechanisms and treatment options. Depression and anxiety in MS, like in many other neuroimmune disorders, are related, among others, to multi-regional patterns of cerebral disturbances and complex pathogenic mechanisms that deserve further elucidation as a basis for early diagnosis and adequate management to improve the quality of life in this disabling disease.

Enviromental endocrine disruptor risks in the central nervous system: Neurotoxic effects of PFOS and glyphosate

Endocrine disruptors (EDs) pose significant risks to human and environmental health, with potential implications for neurotoxicity. This study investigates the synergistic neurotoxic effects of perfluorooctane sulfonate (PFOS) and glyphosate (GLY), two ubiquitous EDs, using SHSY5Y neuronal and C6 astrocytic cell lines. While individual exposures to PFOS and glyphosate at non-toxic concentrations did not induce significant changes, their combination resulted in a marked increase in oxidative stress and neuroinflammatory responses. Specifically, the co-exposure led to elevated levels of interleukin-6, tumor necrosis factor alpha, and interferon gamma, along with reduced interleukin-10 expression, indicative of heightened neuroinflammatory processes. These findings underscore the importance of considering the synergistic interactions of EDs in assessing neurotoxic risks and highlight the urgent need for further research to mitigate the adverse effects of these compounds on neurological health.

A novel probiotic formula, BLLL, ameliorates chronic stress-induced depression-like behaviors in mice by reducing neuroinflammation and increasing neurotrophic factors

Introduction: Probiotics have been recognized for their various biological activities, including antioxidant and anti-inflammatory properties. This study investigates the therapeutic effect of a novel probiotic formula, BLLL, consisting of Bifidobacterium breve, Lactobacillus plantarum, Lactobacillus paracasei, and Lactobacillus helveticus, on chronic stress-induced depression-like behaviors in mice. Methods: The BLLL formula or phosphate-buffered saline (PBS) was given orally at a dose of 2, 4, or 8 × 1010 CFU/kg once daily for 10 days in mice treated with chronic unpredictable stress (CUS) treated or vehicle. Depression-like behaviors were assessed using the sucrose preference test (SPT), the forced swimming test (FST), and the tail suspension test (TST). The mRNA and/or protein expression of interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), IL-4, IL-10, and chitinase-3-like protein 3 (CHI3L1, also known as Ym-1), as well as the concentration of nitrite, malondialdehyde (MDA), glutathione (GSH), and brain-derived neurotrophic factor (BDNF) in the hippocampus and medial prefrontal cortex were examined. Results: The BLLL formula treatment at a dose of 8 × 1010 CFU/kg, but not at a dose of 2 or 4 × 1010 CFU/kg, improved CUS-induced depression-like behaviors in mice, as shown by the decrease in immobility time in the TST and FST and the increase in sucrose intake in the SPT. Further analysis revealed that BLLL treatment suppressed the CUS-induced increase in IL-1β, IL-6, and TNF-α mRNA and protein levels, as well as the CUS-induced decrease in IL-4, IL-10, and Ym-1 mRNA and/or protein levels in the hippocampus and medial prefrontal cortex. In addition, treatment with the BLLL formula countered the CUS-induced increase in nitrite and MDA levels and the CUS-induced decrease in GSH content and BDNF concentration in the hippocampus and medial prefrontal cortex. Conclusion: These results demonstrate that the novel probiotic formula BLLL ameliorates chronic stress-induced depression-like behavior in mice by suppressing neuroinflammation and oxido-nitrosative stress in the brain.

Kynurenines and Inflammation: A Remarkable Axis for Multiple Sclerosis Treatment

Multiple sclerosis (MS) is a chronic inflammatory autoimmune neurological disease characterized by the recurrent appearance of demyelinating lesions and progressive disability. Currently, there are multiple disease-modifying treatments, however, there is a significant need to develop new therapeutic targets, especially for the progressive forms of the disease. This review article provides an overview of the most recent studies aimed at understanding the inflammatory processes that are activated in response to the accumulation of kynurenine pathway (KP) metabolites, which exacerbate an imbalance between immune system cells (e.g., Th1, Th2, and T reg) and promote the release of pro-inflammatory interleukins that modulate different mechanisms: membrane-receptors function; nuclear factors expression; and cellular signals. Together, these alterations trigger cell death mechanisms in brain cells and promote neuron loss and axon demyelination. This hypothesis could represent a remarkable approach for disease-modifying therapies for MS. Here, we also provide a perspective on the repositioning of some already approved drugs involved in other signaling pathways, which could represent new therapeutic strategies for MS treatment.

Advances in research on immunocyte iron metabolism, ferroptosis, and their regulatory roles in autoimmune and autoinflammatory diseases

Autoimmune diseases commonly affect various systems, but their etiology and pathogenesis remain unclear. Currently, increasing research has highlighted the role of ferroptosis in immune regulation, with immune cells being a crucial component of the body's immune system. This review provides an overview and discusses the relationship between ferroptosis, programmed cell death in immune cells, and autoimmune diseases. Additionally, it summarizes the role of various key targets of ferroptosis, such as GPX4 and TFR, in immune cell immune responses. Furthermore, the release of multiple molecules, including damage-associated molecular patterns (DAMPs), following cell death by ferroptosis, is examined, as these molecules further influence the differentiation and function of immune cells, thereby affecting the occurrence and progression of autoimmune diseases. Moreover, immune cells secrete immune factors or their metabolites, which also impact the occurrence of ferroptosis in target organs and tissues involved in autoimmune diseases. Iron chelators, chloroquine and its derivatives, antioxidants, chloroquine derivatives, and calreticulin have been demonstrated to be effective in animal studies for certain autoimmune diseases, exerting anti-inflammatory and immunomodulatory effects. Finally, a brief summary and future perspectives on the research of autoimmune diseases are provided, aiming to guide disease treatment strategies.

Effects of crocin on inflammatory biomarkers and mental health status in patients with multiple sclerosis: A randomized, double-blinded clinical trial

BACKGROUND

Multiple sclerosis (MS), as a demyelinating disease correlated with inflammation and oxidative stress, affects the central nervous system and causes a wide range of complications, including psychiatric disorders. Considering the anti-inflammatory and antioxidant properties associated with the bioactive components of saffron, such as crocin (trans-crocetin bis(β-d-gentiobiosyl) ester), and their potential impact on ameliorating psychiatric symptoms, our study aimed to investigate the effect of crocin on biomarkers of inflammation, oxidative stress, and mental health, e.g., depression and anxiety in individuals with MS.

METHOD

Patients with MS were randomized into two groups, taking either 15 mg crocin tablets twice a day (n = 25; 30 mg/day) or placebo tablets (n = 25) for 8 weeks. The valid and reliable Beck depression and anxiety scale questionnaire was recorded, and fasting blood samples were collected to measure biomarkers, including high-sensitivity C-reactive protein (hs-CRP), malondialdehyde (MDA), and nitric oxide (NO) at baseline and week 8 following the intervention.

RESULTS

The data analysis using ANCOVA showed that supplementation with crocin for 8 weeks significantly lowered hs-CRP levels (p-value= 0.01). In addition, within-group comparisons showed crocin significantly decreased anxiety (p-value= 0.01). However, crocin did not affect serum MDA and NO after 8 weeks of intervention.

CONCLUSION

Our findings suggest that crocin may keep promise in attenuating inflammation, evidenced by reducing hs-CRP in patients with MS. However, supplementation for 8 weeks may not be sufficient to improve mental health, and future clinical studies with higher sample sizes and various doses and durations are recommended.

The effects of Ellagic acid supplementation on neurotrophic, inflammation, and oxidative stress factors, and indoleamine 2, 3-dioxygenase gene expression in multiple sclerosis patients with mild to moderate depressive symptoms: A randomized, triple-blind, placebo-controlled trial

BACKGROUND

Depression is one of the most common psychological disorders among multiple sclerosis (MS) patients that characterized as the first symptoms. Ellagic acid is a natural polyphenol that may have neuroprotective properties through antioxidant, anti-inflammatory, and immunomodulatory effects.

PURPOSE

The aim of the present study was to investigate the effects of Ellagic acid on circulating levels of brain derived neurotrophic factor (BDNF), interferon-γ (IFN-ƴ), nitric oxide (NO), nuclear factor erythroid-2-related factor 2 (Nrf2), cortisol, serotonergic system, and indoleamine 2, 3-dioxygenase (IDO) gene expression in MS patients with mild to moderate depressive symptoms.

STUDY DESIGN

A randomized triple-blind clinical trial.

METHODS

The eligible patients according to the inclusion criteria were randomly divided into two groups: either 180 mg Ellagic acid (Axenic company) (n = 25) or 180 mg maltodextrin (n = 25) group for 12 weeks. The Ellagic acid supplement were identical to placebo in shape, color and odor. Serum BDNF, NO, Nrf2, cortisol, serotonin, and IFN-ƴ were measured by ELISA kit in the baseline and end of the study. Also, demographic characteristics, anthropometric measurements, physical activity, food intake, Beck Depression Inventory-II (BDI-II) and expanding disability status scale (EDSS) questionnaires, as well as IDO gene expression were assessed. SPSS software version 24 was used for statistical analysis.

RESULTS

Fifty patients were evaluated, and a significant decrease in BDI-II (p = 0.001), IFN-ƴ (p = 0.001), NO (p = 0.004), cortisol (p = 0.015), IDO gene expression (p = 0.001) and as well as increased the level of BDNF (p = 0.006) and serotonin (p = 0.019) was observed among those who received 90 mg Ellagic acid twice a day for 12 weeks versus control group. However, there were no significant differences between groups for Nrf2 levels (p>0.05) at the end of study.

CONCLUSION

The current study indicates that Ellagic acid intervention has a favorable effect on depression in MS patients. This is achieved by reducing BDI-II scores, as well as levels of NO, cortisol, IFN-ƴ, and IDO gene expression. Furthermore, we found a significant elevation in circulating levels of BDNF and serotonin.

Pathogenic Role of Fibrinogen in the Neuropathology of Multiple Sclerosis: A Tale of Sorrows and Fears

Multiple sclerosis (MS) is an autoimmune demyelinating neurodegenerative disease of the central nervous system (CNS) due to injury of the myelin sheath by immune cells. The clotting factor fibrinogen is involved in the pathogenesis of MS by triggering microglia and the progress of neuroinflammation. Fibrinogen level is correlated with MS severity; consequently, inhibition of the fibrinogen cascade may reduce MS neuropathology. Thus, this review aimed to clarify the potential role of fibrinogen in the pathogenesis of MS and how targeting of fibrinogen affects MS neuropathology. Accumulation of fibrinogen in the CNS may occur independently or due to disruption of blood-brain barrier (BBB) integrity in MS. Fibrinogen acts as transduction and increases microglia activation which induces the progression of inflammation, oxidative stress, and neuronal injury. Besides, brain fibrinogen impairs the remyelination process by inhibiting the differentiation of oligodendrocyte precursor cells. These findings proposed that fibrinogen is associated with MS neuropathology through interruption of BBB integrity, induction of neuroinflammation, and demyelination with inhibition of the remyelination process by suppressing oligodendrocytes. Therefore, targeting of fibrinogen and/or CD11b/CD18 receptors by metformin and statins might decrease MS neuropathology. In conclusion, inhibiting the expression of CD11b/CD18 receptors by metformin and statins may decrease the pro-inflammatory effect of fibrinogen on microglia which is involved in the progression of MS.

Clinical and psychological aspects in a group of allergic asthma patients and the impact on their health status perception

BACKGROUND

The interplay between physical and psychological symptoms frequently affects the health-related quality of life of asthma patients.

PARTICIPANTS AND PROCEDURE

This research aimed at assessing the psychological status of 60 patients attending their first/second doctor visit at which they were diagnosed with allergic asthma. Information on psychological distress was collected through the Symptom Questionnaire (SQ), personality traits were described through Cattell's 16-Personality Factor Questionnaire (16-PF), stress-related behavior was detected through the P Stress Questionnaire (PSQ), and the perceived quality of life was described with the Rhinasthma questionnaire.

RESULTS

The SQ revealed anxiety levels above the clinical cut-off in 71.7% of patients, levels of depression in 46.7%, anger-hostility in 53.3%, and somatic symptoms in 65%. No significant differences were observed after three months. The 16-PF scores were also suggestive of specific personality traits associated with the predisposition towards psychosomatic disorders. However, no stress-related behaviors were observed with the PSQ. Rhinasthma highlighted a certain degree of the perceived quality of life. Additionally, the quality of life correlated with age, all psychological distress scales, a few personality traits, vigor, and stress disorders.

CONCLUSIONS

Allergic asthma patients present a higher-than-average level of psychological distress and impaired perceived quality of life at the time of diagnosis. Therefore, it is important to assess the psychological status in addition to the respiratory function.

Astrocyte-derived extracellular vesicles in stress-associated mood disorders. Does the immune system get astrocytic?

Life stressors can wreak havoc on our health, contributing to mood disorders like major depressive disorder (MDD), a widespread and debilitating condition. Unfortunately, current treatments and diagnostic strategies fall short of addressing these disorders, highlighting the need for new approaches. In this regard, the relationship between MDD, brain inflammation (neuroinflammation), and systemic inflammation in the body may offer novel insights. Recent research has uncovered the crucial role of astrocytes in coordinating the inflammatory response through the release of extracellular vesicles (ADEVs) during different neuroinflammatory conditions. While the contribution of ADEVs to stress and MDD remains largely unexplored, their potential to modulate immune cells and contribute to MDD pathogenesis is significant. In this article, we delve into the immunomodulatory role of ADEVs, their potential impact on peripheral immune cells, and how their microRNA (miRNA) landscape may hold the key to controlling immune cell activity. Together, these mechanisms may constitute an opportunity to develop novel therapeutic pharmacological approaches to tackle mood disorders.

Mood Symptoms and Chronic Fatigue Syndrome Due to Relapsing-Remitting Multiple Sclerosis Are Associated with Immune Activation and Aberrations in the Erythron

BACKGROUND

Multiple sclerosis (MS) is a chronic autoimmune and neuroinflammatory disease of the central nervous system characterized by peripheral activation of immune-inflammatory pathways which culminate in neurotoxicity causing demyelination of central neurons. Nonetheless, the pathophysiology of relapsing-remitting MS (RRMS)-related chronic fatigue, depression, anxiety, cognitive impairments, and autonomic disturbances is not well understood.

OBJECTIVES

The current study aims to delineate whether the remitted phase of RRMS is accompanied by activated immune-inflammatory pathways and if the latter, coupled with erythron variables, explain the chronic fatigue and mood symptoms due to RRMS.

MATERIAL AND METHODS

We recruited 63 MS patients, 55 in the remitted phase of RRMS and 8 with secondary progressive MS, and 30 healthy controls and assessed erythron variables, and used a bio-plex assay to measure 27 serum cytokines.

RESULTS

A significant proportion of the MS patients (46%) displayed activation of the immune-inflammatory response (IRS) and compensatory immune response (CIRS) systems, and T helper (Th)1 and Th17 cytokine profiles. Remitted RRMS patients showed increased chronic fatigue, depression, anxiety, physiosomatic, autonomic, and insomnia scores, which could partly be explained by M1 macrophage, Th1, Th-17, growth factor, and CIRS activation, as well as aberrations in the erythron including lowered hematocrit and hemoglobin levels.

CONCLUSIONS

Around 50% of remitted RRMS patients show activation of immune-inflammatory pathways in association with mood and chronic-fatigue-like symptoms. IRS and CIRS activation as well as the aberrations in the erythron are new drug targets to treat chronic fatigue and affective symptoms due to MS.

Need for Multidimensional and Multidisciplinary Management of Depressed Preadolescents and Adolescents: A Review of Randomized Controlled Trials on Oral Supplementations (Omega-3, Fish Oil, Vitamin D3)

(1) Background: Depression is a serious health problem with a high cost for public administration. Epidemiological studies report that one in five children have a mental disorder and about 50% of mental health problems exacerbate in childhood and adolescence. Moreover, the antidepressant efficacy in children and adolescents is poorly demonstrated and can cause severe behavioral adverse events such as suicidal ideation. (2) Methods: This systematic literature review examined oral supplementations (Omega-3, fish oil, Vitamin D₃) to treat depressed children, preadolescents, and adolescents. MEDLINE, Scopus, Embase, and PsycInfo were searched for articles published in the last five years. Six studies met the eligibility criteria. The inclusion criteria encompassed children, preadolescents, and adolescents, a diagnosis of depression, and an intervention of oral supplementations such as Omega-3, fish oil, and Vitamin D₃. (3) Results: Most of the studies demonstrated that dietary intervention provides positive outcomes in terms of depression symptoms. (4) Conclusions: Overall, the results demonstrate a positive effect for oral supplementation suggesting an increase intake of Omega-3, fish oil, and Vitamin D₃. However, only a few studies assess the effectiveness of diet recommendations, as a monotherapy or combined treatment, for the management of depression at developmental ages. Thus, there is still a need to further investigate these aspects and to look more specifically at adolescents and preadolescents.

Possible role of the NLRP3 inflammasome and the gut-brain axis in multiple sclerosis-related depression

Multiple sclerosis (MS) is an autoimmune and demyelinating disease of the central nervous system that results from complex interactions between genetic and environmental determinants. Patients with MS exhibit a high risk of depression, however, the exact pathomechanisms remain largely unknown. It is becoming widely accepted that the gut-brain axis (GBA) disorders may exert an influence on neuroinflammation and psychiatric symptoms, including so-called MS-related depression. The element suggested as a bridge between intestinal disorders, depression, and MS is an inflammatory response with the central role of the NLR family pyrin domain containing 3 (NLRP3) inflammasome. The pro-inflammatory activity of effector cytokines of the NLRP3 inflammasome forms the hypothesis that it is actively involved in the development of inflammatory and autoimmune diseases. Despite extensive reviews considering the possible origins of MS-related depression, its complex pathophysiology prevents any easy determination of its underlying mechanisms. This paper aims to discuss molecular mechanisms related to the GBA axis that can mediate dysbiosis, intestinal barrier dysfunction, disruption of blood-brain barrier integrity, neuroinflammation, and subsequent manifestation of MS-related major depressive disorder.

Health Related Quality of Life and Psychopathological Symptoms in People with Hemophilia, Bloodborne Co-Infections and Comorbidities: An Italian Multicenter Observational Study

Background

The health-related quality of life (HRQoL) of people with hemophilia (PWH) is an important issue, especially considering people suffering from chronic diseases beyond hemophilia. The principal aim of this study was to investigate the presence and relevance of psychological symptoms, both internalizing and externalizing, lifestyle, and HRQoL in a group of Italian PWH with chronic bloodborne co-infections and comorbidities. Furthermore, the research describes the association between psychological aspects and the impact of disease-related characteristics (type of hemophilia, presence of co-infections, and comorbidities) on them.

Methods

Seventy patients (mean age 46.77±11.3), 64 with severe hemophilia A (Factor VIII: C < 1 IU/dL) and 6 with severe hemophilia B (Factor IX <1 IU/dL), were consecutively recruited from seven Hemophilia Centers in Italy of Italian Association of Hemophilia Centers (AICE). In order to assess psychological symptoms, HRQoL, and lifestyle, three psychological questionnaires were administered (the SCL-90-R, SF-36, and PSQ, respectively).

Results

A general decline in the quality of life and an increase in the tendency to adopt a lifestyle characterized by hyperactivity emerged. Inverse correlations were found between HRQoL and psychological distress. Although the SCL-90-R did not reveal symptoms above the clinical cut-off, co-infections significantly increased anxiety, depression, somatizations, paranoia, and social withdrawal. Lastly, HRQoL is impaired by co-infections as well as comorbidities.

Conclusion

Our preliminary results must be confirmed to deepen the findings between mental health and hemophilia.

Association between neutrophil to lymphocyte ratio and depression among US adults: From a large population-based cross-sectional study

OBJECTIVE

The study aims to determine the association between neutrophil to lymphocyte ratio (NLR) and depression and severity.

METHODS

We conducted a cross-sectional analysis of the National Health and Nutrition Examination Survey (NHANES). The Patient Health Questionnaire (PHQ-9) was administered to assess depression and its severity. NLR was calculated as a neutrophil count-to-lymphocyte count ratio.

RESULTS

The study included 22,207 adults (mean age, 44.43 years; women, 51.05%), and 1671 (6.54%) reported depression. The association between NLR and depression was not significant (odds ratio [OR], 1.06, 95% confidence interval [CI], 0.98 to 1.15, p = 0.12) after fully adjusting the covariates, and similar results (Q1 reference Vs Q2: OR, 0.87, 95%CI, 0.70 to 1.07 Vs Q3: OR, 0.99, 95%CI, 0.80 to 1.21 Vs Q4: OR, 1.08, 95%CI, 0.86 to 1.35, p for trend 0.21) when NLR as a categorical variable. After controlling for all confounding variables, a U-shaped relationship between NLR and depression severity was observed, and the inflection point was 1.78. Subgroup analyses showed a significant association among Mexican American/other Hispanic (OR, 1.13, 95%CI, 1.00 to 1.28, p = 0.04), non-Hispanic blacks (OR, 1.18, 95%CI, 1.07 to 1.32, p = 0.002), the subjects with poverty income ratio above four (OR, 1.24, 95%CI, 1.00 to 1.53, p = 0.048) between NLR and depression. The results from the sensitivity analyses remained stable.

CONCLUSION

The association between NLR and depression is not general across depressed populations among US adults. This association may be specific to subgroups. The relationship between NLR and depression severity is non-linear.

Th17-cells in depression: Implication in multiple sclerosis

Depression is one of the most common neuropsychological symptoms of multiple sclerosis. However, in addition to mood disorder, depression can also influence on multiple sclerosis course. The mechanism of this dependence is not fully understood. The recent studies suggest the possible common immune mechanisms in the pathogenesis of depression and multiple sclerosis. In particular, it was shown that along with biogenic amines disturbance, neuroinflammation also play an important role in the pathogenesis of depression. Significant attention is drawn to Th17-cells subsets, which are considered as critical players in the pathogenesis of inflammatory diseases of the central nervous system, including multiple sclerosis. This brief report reviews the literature data on the role of neuroinflammation in the reciprocal influence of multiple sclerosis and depression with focus on Th17-cells, which may underlie pathogenetic mechanisms of both this diseases.

Involvement of TLR2-TLR4, NLRP3, and IL-17 in pain induced by a novel Sprague-Dawley rat model of experimental autoimmune encephalomyelitis

Up to 92% of patients suffering from multiple sclerosis (MS) experience pain, most without adequate treatment, and many report pain long before motor symptoms associated with MS diagnosis. In the most commonly studied rodent model of MS, experimental autoimmune encephalomyelitis (EAE), motor impairments/disabilities caused by EAE can interfere with pain testing. In this study, we characterize a novel low-dose myelin-oligodendrocyte-glycoprotein (MOG)-induced Sprague-Dawley (SD) model of EAE-related pain in male rats, optimized to minimize motor impairments/disabilities. Adult male SD rats were treated with increasing doses of intradermal myelin-oligodendrocyte-glycoprotein (MOG1-125) (0, 4, 8, and 16 μg) in incomplete Freund's adjuvant (IFA) vehicle to induce mild EAE. Von Frey testing and motor assessments were conducted prior to EAE induction and then weekly thereafter to assess EAE-induced pain and motor impairment. Results from these studies demonstrated that doses of 8 and 16 μg MOG1-125 were sufficient to produce stable mechanical allodynia for up to 1 month in the absence of hindpaw motor impairments/disabilities. In the follow-up studies, these doses of MOG1-125, were administered to create allodynia in the absence of confounded motor impairments. Then, 2 weeks later, rats began daily subcutaneous injections of the Toll-like receptor 2 and 4 (TLR2-TLR4) antagonist (+)-naltrexone [(+)-NTX] or saline for an additional 13 days. We found that (+)-NTX also reverses EAE-induced mechanical allodynia in the MOG-induced SD rat model of EAE, supporting parallels between models, but now allowing a protracted timecourse to be examined completely free of motor confounds. Exploring further mechanisms, we demonstrated that both spinal NOD-like receptor protein 3 (NLRP3) and interleukin-17 (IL-17) are necessary for EAE-induced pain, as intrathecal injections of NLRP3 antagonist MCC950 and IL-17 neutralizing antibody both acutely reversed EAE-induced pain. Finally, we show that spinal glial immunoreactivity induced by EAE is reversed by (+)-NTX, and that spinal demyelination correlates with the severity of motor impairments/disabilities. These findings characterize an optimized MOG-induced SD rat model of EAE for the study of pain with minimal motor impairments/disabilities. Finally, these studies support the role of TLR2-TLR4 antagonists as a potential treatment for MS-related pain and other pain and inflammatory-related disorders.

Oxidative stress and antioxidant defenses in mild cognitive impairment: A systematic review and meta-analysis

This study aims to systematically review and meta-analyze the nitro-oxidative stress (O&NS)/antioxidant (ANTIOX) ratio in the peripheral blood of people with mild cognitive impairment (MCI). We searched PubMed, Scopus, Google Scholar, and Web of Science for articles published from inception until July 31, 2021. Forty-six studies on 3.798 MCI individuals and 6.063 healthy controls were included. The O&NS/ANTIOX ratio was significantly higher in MCI than in controls with a Standardized Mean Difference (SMD)= 0.378 (95% CI: 0.250; 0.506). MCI individuals showed increased lipid peroxidation (SMD=0.774, 95%CI: 4.416; 1.132) and O&NS-associated toxicity (SMD=0.621, CI: 0.377; 0.865) and reduced glutathione (GSH) defenses (SMD=0.725, 95%CI: 0.269; 1.182) as compared with controls. MCI was also accompanied by significantly increased homocysteine (SMD=0.320, CI: 0.059; 0.581), but not protein oxidation, and lowered non-vitamin (SMD=0.347, CI: 0.168; 0.527) and vitamin (SMD=0.564, CI: 0.129; 0.999) antioxidant defenses. The results show that MCI is at least in part due to increased neuro-oxidative toxicity and suggest that treatments targeting lipid peroxidation and the GSH system may be used to treat or prevent MCI.

Alleviative effects of foraging exercise on depressive-like behaviors in chronic mild stress-induced ischemic rat model

BACKGROUND

Poststroke depression (PSD) is a common complication that seriously affects the functional recovery and prognosis of an individual. As some patients with PSD fail to respond to drug therapy, it is urgent to find a viable alternative treatment.

METHODS

An active exercise program known as foraging exercise (FE), using food as bait, was designed. First, focal ischemia and chronic unpredictable mild stress (CUMS) were used to establish a PSD model in rats. FE was then performed for 4 weeks. Body weight and behavioral assessments were conducted at the end of the 4^th and 8^th weeks.

RESULTS

After 8 weeks, the results revealed that, compared with the PSD group, the behavioral scores of the rats in the PSD/FE group were significantly improved, the expression of Iba-1 in the affected frontal lobe and striatum was decreased, and serum levels of IL-6 and the IL-6/IL-10 ratio were downregulated. However, the ratio of residual brain volume in rats that had experienced CUMS was significantly less than that in the stroke group.

CONCLUSION

FE can alleviate the behavioral scores of PSD rats, and its mechanism may be related to a modulation of the immune-inflammation response of microglia. Furthermore, chronic, persistent stress may increase the volume of cerebral infarction after stroke.

Therapeutic Potentials of Poly (ADP-Ribose) Polymerase 1 (PARP1) Inhibition in Multiple Sclerosis and Animal Models: Concept Revisiting

Poly (ADP-ribose) polymerase 1 (PARP1) plays a fundamental role in DNA repair and gene expression. Excessive PARP1 hyperactivation, however, has been associated with cell death. PARP1 and/or its activity are dysregulated in the immune and central nervous system of multiple sclerosis (MS) patients and animal models. Pharmacological PARP1 inhibition is shown to be protective against immune activation and disease severity in MS animal models while genetic PARP1 deficiency studies reported discrepant results. The inconsistency suggests that the function of PARP1 and PARP1-mediated PARylation may be complex and context-dependent. The article reviews PARP1 functions, discusses experimental findings and possible interpretations of PARP1 in inflammation, neuronal/axonal degeneration, and oligodendrogliopathy, three major pathological components cooperatively determining MS disease course and neurological progression, and points out future research directions. Cell type specific PARP1 manipulations are necessary for revisiting the role of PARP1 in the three pathological components prior to moving PARP1 inhibition into clinical trials for MS therapy.

Activation of 5-HT1A receptor reduces abnormal emotionality in stress-maladaptive mice by alleviating decreased myelin protein in the ventral hippocampus

We previously reported that abnormal emotionality in stress-maladaptive mice was ameliorated by chronic treatment with flesinoxan, a 5-HT_1A receptor agonist. Furthermore, the maintenance of hippocampal myelination appeared to contribute to the development of stress adaptation in mice. However, the effects of 5-HT_1A receptor activation on myelination under the stress-maladaptive situations and the underlying mechanisms remain unknown. In the present study, we examined using flesinoxan whether activation of 5-HT_1A receptor can reduce an abnormal emotional response by acting on oligodendrocytes to preserve myelin proteins in stress-maladaptive mice. Mice were exposed to repeated restraint stress for 4 h/day for 14 days as a stress-maladaptive model. Flesinoxan was given intraperitoneally immediately after the daily exposure to restraint stress. After the final exposure to restraint stress, the emotionality of mice was evaluated by the hole-board test. The expression levels of brain-derived neurotrophic factor (BDNF), phosphorylated-extracellular signal-regulated kinase (p-ERK), phosphorylated-cAMP response element-binding protein (p-CREB), myelin-associated glycoprotein (MAG), myelin basic protein (MBP) and oligodendrocyte transcription factor 2 (olig2) in the hippocampus was assessed by western blotting. Hippocampal oligodendrogenesis were examined by immunohistochemistry. Chronic treatment with flesinoxan suppressed the decrease in head-dipping behaviors in stress-maladaptive mice in the hole-board test. Under this condition, the decreases in MAG and MBP in the hippocampus recovered with increase in BDNF, p-ERK, p-CREB, and olig2. Furthermore, hippocampal oligodendrogenesis in stress-maladaptive mice was promoted by chronic treatment with flesinoxan. These findings suggest that 5-HT_1A receptor activation may promote oligodendrogenesis and myelination via an ERK/CREB/BDNF signaling pathway in the hippocampus and reduces abnormal emotionality due to maladaptation to excessive stress.

Relationship Between Interpersonal Depressive Symptoms and Reduced Amygdala Volume in People with Multiple Sclerosis: Considerations for Clinical Practice

Background

The lifetime prevalence of depression in people with multiple sclerosis (MS) is approximately 50% compared with around 15% in the general population. There is a relationship between depression and quality of life in people with MS and evidence that depression may contribute to disease progression.

Methods

This cross-sectional pilot study assessed the association between depression and regional brain atrophy, including amygdala and hippocampal volume. Forty-nine participants with MS recruited through a hospital MS clinic were administered the Center for Epidemiological Studies Depression Scale Revised (CESD-R) to investigate whether higher endorsements on the items depressive affect and interpersonal symptoms were associated with volumetric magnetic resonance imaging measurements of hippocampal and amygdala atrophy.

Results

Regression analysis revealed an association between depression-related interpersonal symptoms and right amygdala volume. No association was found between depression and hippocampal volume.

Conclusions

These results provide preliminary support for a unilateral, biologically based relationship between the right amygdala and characteristic interpersonal depressive symptoms expressed by people with MS and add to the growing body of literature implicating regional brain atrophy in MS-associated depression. Given that the interpersonal subcomponent of the CESD-R measures social functioning, and the neural networks in the amygdala are known to be implicated in processing social stimuli, this research suggests that targeted diagnosis and treatments for depression in people with MS may be particularly beneficial. Further confirmatory research of this relationship is required.

Understanding the role of S-nitrosylation/nitrosative stress in inflammation and the role of cellular denitrosylases in inflammation modulation: Implications in health and diseases

S-nitrosylation is a very fundamental post-translational modification of protein and non-protein thiols due the involvement of it in a variety of cellular processes including activation/inhibition of several ion channels such as ryanodine receptor in the cardiovascular system; blood vessel dilation; cGMP signaling and neurotransmission. S-nitrosothiol homeostasis in the cell is tightly regulated and perturbations in homeostasis result in an altered redox state leading to a plethora of disease conditions. However, the exact role of S-nitrosylated proteins and nitrosative stress metabolites in inflammation and in inflammation modulation is not well-reviewed. The cell utilizes its intricate defense mechanisms i.e. cellular denitrosylases such as Thioredoxin (Trx) and S-nitrosoglutathione reductase (GSNOR) systems to combat nitric oxide (NO) pathology which has also gained current attraction as novel anti-inflammatory molecules. This review attempts to provide state-of-the-art knowledge from past and present research on the mechanistic role of nitrosative stress intermediates (RNS, OONO^-, PSNO) in pulmonary and autoimmune diseases and how cellular denitrosylases particularly GSNOR and Trx via imparting opposing effects can modulate and reduce inflammation in several health and disease conditions. This review would also bring into notice the existing gaps in current research where denitrosylases can be utilized for ameliorating inflammation that would leave avenues for future therapeutic interventions.

Glatiramer acetate attenuates depressive/anxiety-like behaviors and cognitive deficits induced by post-weaning social isolation in male mice

RATIONALE

Major depressive disorder (MDD) is a debilitating disorder with adverse effects on mood, memory, and quality of life.

OBJECTIVES

In this study, the antidepressant potential of glatiramer acetate (GA), a drug used in the management of multiple sclerosis, was investigated in acute and chronic models of depression in male mice. The acute antidepressant screening was performed with the forced swim (FST) and tail suspension (TST) tests. In the chronic phase, post-weaning social isolation (SI) was used to induce depressive-/anxiety-like behaviors.

METHODS

Mice were reared in two different groups of social (SG) and isolated (IG) for 4 weeks. IG mice were treated with 0.5, 1.0, and 2.0 mg/kg of GA for the last 2 weeks of the SI period. Animals were assessed by the behavioral tests of depression, anxiety, learning, and memory, and hippocampal brain-derived neurotrophic factor (BDNF) level was measured.

RESULTS

The acute tests confirmed the antidepressant potential of GA. In the chronic phase, GA could reduce immobility time in FST (P < 0.05), increase exploration activity in open field test (P < 0.05), increase open arms duration (P < 0.05) and entries in elevated plus maze (P<0.001), and improve memory and learning in passive avoidance test (P < 0.05). The BDNF level was increased in IG mice and decreased in IG mice treated with GA.

CONCLUSIONS

Our results showed that GA improved depressive-/anxiety-like behaviors and cognitive dysfunction of SI reared mice without increasing the BDNF level which may be associated with other mechanisms of actions of GA.

MicroRNAs, Multiple Sclerosis, and Depression

Multiple sclerosis (MS) is a chronic disease of the central nervous system that affects the brain and spinal cord. There are several disease courses in MS including relapsing–remitting MS (RRMS), primary progressive MS (PPMS), and secondary progressive MS (SPMS). Up to 50% of MS patients experience depressive disorders. Major depression (MD) is a serious comorbidity of MS. Many dysfunctions including neuroinflammation, peripheral inflammation, gut dysbiosis, chronic oxidative and nitrosative stress, and neuroendocrine and mitochondrial abnormalities may contribute to the comorbidity between MS and MD. In addition to these actions, medical treatment and microRNA (miRNA) regulation may also be involved in the mechanisms of the comorbidity between MS and MD. In the study, I review many common miRNA biomarkers for both diseases. These common miRNA biomarkers may help further explore the association between MS and MD.

TRPA1 involvement in depression- and anxiety-like behaviors in a progressive multiple sclerosis model in mice

Progressive multiple sclerosis (PMS) is a neurological disease associated with the development of depression and anxiety, but treatments available are unsatisfactory. The transient receptor potential ankyrin 1 (TRPA1) is a cationic channel activated by reactive compounds, and the blockage of this receptor can reduce depression- and anxiety-like behaviors in naive mice. Thus, we investigated the role of TRPA1 in depression- and anxiety-like behaviors in a PMS model in mice. PMS model was induced in C57BL/6 female mice by the experimental autoimmune encephalomyelitis (EAE). Nine days after the PMS-EAE induction, behavioral tests (tail suspension and elevated plus maze tests) were performed to verify the effects of sertraline (positive control), selective TRPA1 antagonist (A-967,079), and antioxidants (α-lipoic acid and apocynin). The prefrontal cortex and hippocampus were collected to evaluate biochemical and inflammatory markers. PMS-EAE induction did not cause locomotor changes but triggered depression- and anxiety-like behaviors, which were reversed by sertraline, A-967,079, α-lipoic acid, or apocynin treatments. The neuroinflammatory markers (AIF1, GFAP, IL-1β, IL-17, and TNF-α) were increased in mice's hippocampus. Moreover, this model did not alter TRPA1 RNA expression levels in the hippocampus but decrease TRPA1 levels in the prefrontal cortex. Moreover, PMS-EAE induced an increase in NADPH oxidase and superoxide dismutase activities and TRPA1 endogenous agonist levels (hydrogen peroxide and 4-hydroxynonenal). TRPA1 plays a fundamental role in depression- and anxiety-like behaviors in a PMS-EAE model; thus, it could be a possible pharmacological target for treating these symptoms in PMS.

Neuroimmune Mechanisms as Novel Treatment Targets for Substance Use Disorders and Associated Comorbidities

Recent studies examining the neurobiology of substance abuse have revealed a significant role of neuroimmune signaling as a mechanism through which drugs of abuse induce aberrant changes in synaptic plasticity and contribute to substance abuse-related behaviors. Immune signaling within the brain and the periphery critically regulates homeostasis of the nervous system. Perturbations in immune signaling can induce neuroinflammation or immunosuppression, which dysregulate nervous system function including neural processes associated with substance use disorders (SUDs). In this review, we discuss the literature that demonstrates a role of neuroimmune signaling in regulating learning, memory, and synaptic plasticity, emphasizing specific cytokine signaling within the central nervous system. We then highlight recent preclinical studies, within the last 5 years when possible, that have identified immune mechanisms within the brain and the periphery associated with addiction-related behaviors. Findings thus far underscore the need for future investigations into the clinical potential of immunopharmacology as a novel approach toward treating SUDs. Considering the high prevalence rate of comorbidities among those with SUDs, we also discuss neuroimmune mechanisms of common comorbidities associated with SUDs and highlight potentially novel treatment targets for these comorbid conditions. We argue that immunopharmacology represents a novel frontier in the development of new pharmacotherapies that promote long-term abstinence from drug use and minimize the detrimental impact of SUD comorbidities on patient health and treatment outcomes.

Neuroendocrine, neuroinflammatory and pathological outcomes of chronic stress: A story of microglial remodeling

Microglia, the resident macrophage cells of the central nervous system (CNS), are involved in a myriad of processes required to maintain CNS homeostasis. These cells are dynamic and can adapt their phenotype and functions to the physiological needs of the organism. Microglia rapidly respond to changes occurring in their microenvironment, such as the ones taking place during stress. While stress can be beneficial for the organism to adapt to a situation, it can become highly detrimental when it turns chronic. Microglial response to prolonged stress may lead to an alteration of their beneficial physiological functions, becoming either maladaptive or pro-inflammatory. In this review, we aim to summarize the effects of chronic stress exerted on microglia through the neuroendocrine system and inflammation at adulthood. We also discuss how these effects of chronic stress could contribute to microglial involvement in neuropsychiatric and sleep disorders, as well as neurodegenerative diseases.

Ocoxin as a complement to first line treatments in cancer

Chemotherapy and radiotherapy are the most frequent treatment for patients suffering from malignant progression of cancer. Even though new treatments are now being implemented, administration of these chemotherapeutic agents remains as the first line option in many tumor types. However, the secondary effects of these compounds represent one of the main reasons cancer patients lose life quality during disease progression. Recent data suggests that Ocoxin, a plant extract and natural compound based nutritional complement rich in antioxidants and anti-inflammatory mediators exerts a positive effect in patients receiving chemotherapy and radiotherapy. This mixture attenuates the chemotherapy and radiotherapy-related side effects such as radiation-induced skin burns and mucositis, chemotherapy-related diarrhea, hepatic toxicity and blood-infection. Moreover, it has been proven to be effective as anticancer agent in different tumor models both in vitro and in vivo, potentiating the cytotoxic effect of several chemotherapy compounds such as Lapatinib, Gemcitabine, Paclitaxel, Sorafenib and Irinotecan. The aim of this review is to put some light on the potential of this nutritional mixture as an anticancer agent and complement for the standard chemotherapy routine.

Potential major depressive disorder biomarkers in pediatric population - a pilot study

Mental disorders affect 10-20 % of the young population in the world. Major depressive disorder (MDD) is a common mental disease with a multifactorial and not clearly explained pathophysiology. Many cases remain undetected and untreated, which influences patients' physical and mental health and their quality of life also in adulthood. The aim of our pilot study was to assess the prediction value of selected potential biomarkers, including blood cell counts, blood cell ratios, and parameters like peroxiredoxin 1 (PRDX1), tenascin C (TNC) and type IV collagen (COL4) between depressive pediatric patients and healthy peers and to evaluate a short effect of antidepressant treatment. In this study, 27 young depressive patients and 26 non-depressed age-matched controls were included. Blood analyses and immunological assays using commercial kits were performed. Platelet count was the only blood parameter for which the case/control status was statistically significant (p=0.01) in a regression model controlling for the age and gender differences. The results from ELISA analyses showed that the case/control status is a significant predictor of the parameters PRDX1 (p=0.05) and COL4 (p=0.009) in respective regression model considering the age and gender differences between MDD patients and controls. A major finding of this study is that values of platelet count, monocyte to lymphocyte ratio, white blood cell, and monocyte counts were assessed by the Random Forest machine learning algorithm as relevant predictors for discrimination between MDD patients and healthy controls with a power of prediction AUC=0.749.

The pathophysiology of SARS-CoV-2: A suggested model and therapeutic approach

In this paper, a model is proposed of the pathophysiological processes of COVID-19 starting from the infection of human type II alveolar epithelial cells (pneumocytes) by SARS-CoV-2 and culminating in the development of ARDS. The innate immune response to infection of type II alveolar epithelial cells leads both to their death by apoptosis and pyroptosis and to alveolar macrophage activation. Activated macrophages secrete proinflammatory cytokines and chemokines and tend to polarise into the inflammatory M1 phenotype. These changes are associated with activation of vascular endothelial cells and thence the recruitment of highly toxic neutrophils and inflammatory activated platelets into the alveolar space. Activated vascular endothelial cells become a source of proinflammatory cytokines and reactive oxygen species (ROS) and contribute to the development of coagulopathy, systemic sepsis, a cytokine storm and ARDS. Pulmonary activated platelets are also an important source of proinflammatory cytokines and ROS, as well as exacerbating pulmonary neutrophil-mediated inflammatory responses and contributing to systemic sepsis by binding to neutrophils to form platelet-neutrophil complexes (PNCs). PNC formation increases neutrophil recruitment, activation priming and extraversion of these immune cells into inflamed pulmonary tissue, thereby contributing to ARDS. Sequestered PNCs cause the development of a procoagulant and proinflammatory environment. The contribution to ARDS of increased extracellular histone levels, circulating mitochondrial DNA, the chromatin protein HMGB1, decreased neutrophil apoptosis, impaired macrophage efferocytosis, the cytokine storm, the toll-like receptor radical cycle, pyroptosis, necroinflammation, lymphopenia and a high Th17 to regulatory T lymphocyte ratio are detailed.

Chronic fatigue and depression due to multiple sclerosis: Immune-inflammatory pathways, tryptophan catabolites and the gut-brain axis as possible shared pathways

Chronic fatigue and major depression (MDD)-like symptoms are common manifestations of multiple sclerosis (MS), both with huge impact on quality of life. Depression can manifest itself as fatigue, and depressive symptoms are often mistaken for fatigue, and vice versa. The two conditions are sometimes difficult to differentiate, and their relationship is unclear. Whether chronic fatigue and depression occur primarily, secondarily or coincidentally with activated immune-inflammatory pathways in MS is still under debate. We have carried out a descriptive review aiming to gain a deeper understanding of the relationship between chronic fatigue and depression in MS, and the shared pathways that underpin both conditions. This review focuses on immune-inflammatory pathways, the kynurenine pathway and the gut-brain axis. It seems likely that proinflammatory cytokines, tryptophan catabolites (the KYN pathway) and the gut-brain axis are involved in the mechanisms causing chronic fatigue and MDD-like symptoms in MS. However, the evidence base is weak, and more research is needed. In order to advance our understanding of the underlying pathological mechanisms, MS-related fatigue and depression should be examined using a longitudinal design and both immune-inflammatory and KYN pathway biomarkers should be measured, relevant clinical characteristics judiciously registered, and self-report instruments for both fatigue and depression should be used.

Oxidative/Nitroxidative Stress and Multiple Sclerosis

Multiple sclerosis (MS) is a multifactorial, central nervous system, immune-mediated disease characterized by inflammation, demyelination, and neurodegeneration. Evidence suggests a steady rise in MS prevalence over the past five decades in the United States and around the world. Even with increased understanding of immunology, the specific etiological trigger of MS remains unknown. Evidence suggests that oxidative/nitroxidative stress is an important contributor to MS etiology, progression, and clinical symptoms. A multifaceted treatment approach aimed at counteracting oxidative/nitroxidative stress including MS disease-modifying medications, Mediterranean style diet, stress-relieving activities, smoking and alcohol cessation, exercise, and peer support programs is the best way to treat the disease.

Improving Depression Outcome by Patient-Centered Medical Management

(Reprinted with permission from The American Journal of Psychiatry 2018; 175:1187-1198).

miR-504 expression level is increased in multiple sclerosis patients responder to interferon-beta

Multiple sclerosis is immune-mediated disease of the central nervous system characterized by demyelination in axons. IFN-β is first-line treatment of MS. Biomarkers are needed for early prediction of responders and non-responders to therapy in the first month of treatment to avoid further disabilities. In this study, we analyzed the expression level of miR-504 and miR-711 in 52 IFN-β responder patients in comparison to 53 non-responders. In the next step, the in-silico analysis was used to enrich related signaling pathways. The expression level of miR-504 was significantly higher in patients who respond to IFN-β therapy, compared with non-responders and we obtain related statistically significant KEGG molecular signaling pathways. Our findings suggest that miR-504 can be considered as a novel biomarker for response to IFN-b therapy.

Manganese induces autophagy dysregulation: The role of S-nitrosylation in regulating autophagy related proteins in vivo and in vitro

Exposure to excess levels of manganese (Mn) may lead to nitrosative stress and neurotoxic effects on the central nervous system (CNS). The dysfunction of autophagy correlates with Mn-induced nitrosative stress; however, the exact mechanism of Mn-mediated autophagy dysfunction is still unclear. Three S-nitrosylated target proteins, namely, JNK, Bcl-2, and IKKβ, were classified as the pivotal signaling pathway mediators that could play a role in the regulation of autophagy. To reveal whether these three proteins were involved in Mn-mediated autophagy dysregulation, we studied the effects of Mn on C57/BL6 mice and human neuroblastoma cells. Exposing the mice or cells, to 300 μmol/kg or 200 μM Mn, inhibited the degradation system of the autophagy-lysosome pathway. Additionally, in Mn-treated mice or cells, S-nitrosylated JNK, Bcl-2, and IKKβ increased while the level of their phosphorylation reduced. The interaction of Beclin1 and Bcl-2 significantly increased in response to 200 μM Mn, whereas the decrease in phosphorylation of AMPK activated the mTOR pathway. We then used 20 μM 1400 W, an iNOS-specific inhibitor, to neutralize the nitrosative stress induced by Mn. Our results show that 1400 W reduced the S-nitrosylated JNK, Bcl-2, and Ikkβ and relieved their downstream signaling molecular functions. Moreover, pretreatment with 20 μM 1400 W alleviated Mn-induced autophagic dysregulation and nerve cell injury. These findings revealed that S-nitrosylated JNK, Bcl-2, and IKKβ are crucial signaling molecules in the Mn-mediated autophagic dysfunction.

The compensatory antioxidant response system with a focus on neuroprogressive disorders

Major antioxidant responses to increased levels of inflammatory, oxidative and nitrosative stress (ONS) are detailed. In response to increasing levels of nitric oxide, S-nitrosylation of cysteine thiol groups leads to post-transcriptional modification of many cellular proteins and thereby regulates their activity and allows cellular adaptation to increased levels of ONS. S-nitrosylation inhibits the function of nuclear factor kappa-light-chain-enhancer of activated B cells, toll-like receptor-mediated signalling and the activity of several mitogen-activated protein kinases, while activating nuclear translocation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2 or NFE2L2); in turn, the redox-regulated activation of Nrf2 leads to increased levels and/or activity of key enzymes and transporter systems involved in the glutathione system. The Nrf2/Kelch-like ECH-associated protein-1 axis is associated with upregulation of NAD(P)H:quinone oxidoreductase 1, which in turn has anti-inflammatory effects. Increased Nrf2 transcriptional activity also leads to activation of haem oxygenase-1, which is associated with upregulation of bilirubin, biliverdin and biliverdin reductase as well as increased carbon monoxide signalling, anti-inflammatory and antioxidant activity. Associated transcriptional responses, which may be mediated by retrograde signalling owing to elevated hydrogen peroxide, include the unfolded protein response (UPR), mitohormesis and the mitochondrial UPR; the UPR also results from increasing levels of mitochondrial and cytosolic reactive oxygen species and reactive nitrogen species leading to nitrosylation, glutathionylation, oxidation and nitration of crucial cysteine and tyrosine causing protein misfolding and the development of endoplasmic reticulum stress. It is shown how these mechanisms co-operate in forming a co-ordinated rapid and prolonged compensatory antioxidant response system.

The Contribution of Gut Barrier Changes to Multiple Sclerosis Pathophysiology

The gut barrier consists of several components, including the mucus layer, made of mucins and anti-bacterial molecule, the epithelial cells, connected by tight junction proteins, and a mixed population of cells involved in the interplay with microbes, such as M cells, elongations of “antigen presenting cells” dwelling the lamina propria, intraepithelial lymphocytes and Paneth cells secreting anti-bacterial peptides. Recently, the influence of intestinal permeability (IP) changes on organs far from gut has been investigated, and IP changes in multiple sclerosis (MS) have been described. A related topic is the microbiota dysfunction that underpins the development of neuroinflammation in animal models and human diseases, including MS. It becomes now of interest to better understand the mechanisms through which IP changes contribute to pathophysiology of neuroinflammation. The following aspects seem of relevance: studies on other biomarkers of IP alterations; the relationship with known risk factors for MS development, such as vitamin D deficiency; the link between blood brain barrier and gut barrier breakdown; the effects of IP increase on microbial translocation and microglial activation; the parallel patterns of IP and neuroimmune changes in MS and neuropsychiatric disorders, that afflict a sizable proportion of patients with MS. We will also discuss the therapeutic implications of IP changes, considering the impact of MS-modifying therapies on gut barrier, as well as potential approaches to enhance or protect IP homeostasis.

Depression in adolescent girls: Relationship to serum vitamins a and E, immune response to heat shock protein 27 and systemic inflammation

BACKGROUND

The inflammation and oxidative stress are thought to play an important role in the etiopathogenesis of some psychological disorders. We aimed to assess the potential relationships between serum fat soluble vitamins (Vitamins A and E), antibody titers to Hsp27 (anti-Hsp27) and hematological markers of inflammation, with mood disorders in a population of adolescent girls.

METHODS

A total of 563 adolescent girls (Age 12-18 years) were included in the study. The presence and severity of depression, insomnia and sleepiness were assessed using validated questionnaires. Serum vitamins A and E, anti-Hsp27 antibody titers, white blood cell, lymphocyte, neutrophil, platelet counts, and red blood cell distribution width (RDW), were also measured. Neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), and RDW to platelet ratio (RPR) were calculated.

RESULTS

Serum anti-HSP27 antibody titers, PLR, and RPR values was significantly higher in subjects with a high depression score compared to normal individuals (p < 0.05). However, there was no association between serum inflammatory markers concentrations and sleep disorders; although individuals with insomnia had a lower vitamin E/HDL ratio compared to healthy adolescents. In multivariate logistic regression analyses adjusted for potential confounders, anti-HSP was an independent predictor of severe depression (OR = 5.0, 95% CI: 1.6-15.7, p < 0.05).

LIMITATION

The cross-sectional design of study and the inclusion of only female adolescents participants are limitations.

CONCLUSION

Our findings suggest that serum anti-HSP27 antibody titers may be useful biological marker in depressive patients. This finding may support a role of oxidative stress in the etiology of depression, and targeting this pathway may be of value in the treatment of depression.

Venlafaxine Improves the Cognitive Impairment and Depression-Like Behaviors in a Cuprizone Mouse Model by Alleviating Demyelination and Neuroinflammation in the Brain

Growing evidence has implicated that myelin deficits and neuroinflammation are the coexisted pathological features that contribute to the mood swing and cognitive decline in major depressive disorder (MDD) and multiple sclerosis (MS). Therefore, attenuation of neuroinflammation and reduction of demyelination became newly emerging treatment strategies for the mood and cognitive symptoms. Antidepressant venlafaxine has been used in depression and anxiety through its multiple neuroprotective effects. However, it is unclear whether venlafaxine can improve myelin integrity and alter inflammation status in the brain. By using a well-established cuprizone-induced acute mouse model of demyelination, we investigated the protective effects of venlafaxine on these facets. The cuprizone-fed animals exhibited cognitive impairment and mood disturbances together with myelin loss and prominent neuroinflammation in the brain. Our present study showed that a high dose of venlafaxine alleviated the loss of myelin and oligodendrocytes (OLs), mitigated depression-like behaviors, and improved cognitive function in cuprizone-fed animals. Data from the present study also showed that venlafaxine reduced microglia-mediated inflammation in the brains of cuprizone-fed animals. These findings suggest that venlafaxine may exert its therapeutic effects via facilitating myelin integrity and controlling neuroinflammation, which may provide extra benefits to MS patients with depression and anxiety beyond the symptom management.

The interplay among psychological distress, the immune system, and brain tumor patient outcomes

A malignant brain tumor diagnosis is often accompanied with intense feelings and can be associated with psychosocial conditions including depression, anxiety, and/or increased distress levels. Previous work has highlighted the impact of uncontrolled psychological distress among brain tumor patients. Given the negative impact of maladaptive psychosocial and biobehavioral factors on normal immune system functions, the question remains as to how psychological conditions potentially affect the brain tumor patient anti-tumor immune response. Since immunotherapy has yet to show efficacy at increasing malignant glioma patient survival in all randomized, phase III clinical trials to-date, this review provides new insights into the potential negative effects of chronic distress on brain tumor patient immune functions and outcomes.

Platelet Depletion is Effective in Ameliorating Anxiety-Like Behavior and Reducing the Pro-Inflammatory Environment in the Hippocampus in Murine Experimental Autoimmune Encephalomyelitis

The neuropsychiatric symptoms of multiple sclerosis (MS), such as anxiety and depression, can result from disease activity itself as well as psychological reaction to an unfavorable diagnosis. Accordingly, the literature reports evidence of increased anxiety-like behavior in experimental autoimmune encephalomyelitis (EAE), an accepted MS model. Due to the recently described critical role of platelets in inflammation and autoimmune disease, we examined the relationship between platelets, inflammation, and anxiety-like behavior in EAE. In the elevated plus maze, EAE-induced C57BL/6J mice showed decreased time spent in the open arms relative to vehicle-only controls, demonstrating an increase in anxiety-like behavior. This effect occurred in the presence of platelet–neuron association, but absence of lymphocytic infiltration, in the hippocampal parenchyma. Platelet depletion at the pre-clinical disease stage, using antibody-mediated lysis prevented the EAE-induced increase in anxiety-like behavior, while no significant difference in distance moved was recorded. Furthermore, platelet depletion was also associated with reduction of the pro-inflammatory environment to control levels in the hippocampus and prevention of EAE disease symptomology. These studies demonstrate the high efficacy of a platelet-targeting approach in preventing anxiety-like symptoms and clinical manifestations of EAE and have implications for the treatment of neuropsychiatric symptoms in MS.

Berberine ameliorates lipopolysaccharide-induced learning and memory deficit in the rat: insights into underlying molecular mechanisms

Systemic lipopolysaccharide (LPS) triggers neuroinflammation with consequent development of behavioral and cognitive deficits. Neuroinflammation plays a crucial role in the pathogenesis of neurodegenerative disorders including Alzheimer's disease (AD). Berberine is an isoquinoline alkaloid in Berberis genus with antioxidant and anti-inflammatory property and protective effects in neurodegenerative disorders. In this research, beneficial effect of this alkaloid against LPS-induced cognitive decline was assessed in the adult male rats. LPS was intraperitoneally administered at a dose of 1 mg/kg to induce neuroinflammation and berberine was given via gavage at doses of 10 or 50 mg/kg, one h after LPS, for 7 days. Treatment of LPS group with berberine at a dose of 50 mg/kg (but not at a dose of 10 mg/kg) improved spatial recognition memory in Y maze, performance in novel object recognition task (NORT), and prevented learning and memory dysfunction in passive avoidance tasks. Furthermore, berberine lowered hippocampal activity of acetylcholinesterase (AChE), malondialdehyde (MDA), protein carbonyl, activity of caspase 3, and DNA fragmentation and improved antioxidant capacity through enhancing glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase, and glutathione (GSH). Besides, berberine attenuated inflammation-related indices, as was evident by lower levels of nuclear factor-kappa B (NF-κB), toll-like receptor 4 (TLR4), tumor necrosis factor α (TNFα), and interleukin 6 (IL-6). Berberine also appropriately restored hippocampal 3-nitrotyrosine (3-NT), cyclooxygenase 2 (Cox 2), glial fibrillary acidic protein (GFAP), sirtuin 1, and mitogen-activated protein kinase (p38 MAPK) with no significant alteration of brain-derived neurotrophic factor (BDNF). In summary, berberine could partially ameliorate LPS-induced cognitive deficits via partial suppression of apoptotic cascade, neuroinflammation, oxido-nitrosative stress, AChE, MAPK, and restoration of sirtuin 1.

An Integrative Approach to Neuroinflammation in Psychiatric disorders and Neuropathic Pain

Neuroinflammation is a complex process involving both the peripheral circulation and the Central Nervous System (CNS) and is considered to underlie many CNS disorders including depression, anxiety, schizophrenia, and pain. Stressors including early-life adversity, psychosocial stress, and infection appear to prime microglia toward a pro-inflammatory phenotype. Subsequent inflammatory challenges then drive an exaggerated neuroinflammatory response involving the upregulation of pro-inflammatory mediators that is associated with CNS dysfunction. Several pharmacologic inhibitors of pro-inflammatory cytokines including TNF-α and IL-1β show good clinical efficacy in terms of ameliorating neuroinflammatory processes. Mind/body and plant-based interventions such as yoga, breathing exercises, meditation, and herbs/spices have also been demonstrated to reduce pro-inflammatory cytokines and have a positive impact on depression, anxiety, cognition, and pain. As the intricate connections between the immune system and the nervous system continue to be elucidated, successful therapies for reducing neuroinflammation will likely involve an integrated approach combining drug therapy with nonpharmacologic interventions.

Do Human Endogenous Retroviruses Contribute to Multiple Sclerosis, and if So, How?

The gammaretroviral human endogenous retrovirus (HERV) families MRSV/HERV-W and HERV-H (including the closely related HERV-Fc1) are associated with an increased risk of multiple sclerosis (MS). Complete HERV sequences betray their endogenous retroviral origin, with open reading frames in gag, pro, pol and env being flanked by two long terminal repeats containing promoter and enhancer sequences with the capacity to regulate HERV transactivation and the activity of host genes in spite of endogenous epigenetic repression mechanisms. HERV virions, RNA, cDNA, Gag and Env, and antibodies to HERV transcriptional products, have variously been found in the blood and/or brain and/or cerebrospinal fluid of MS patients, with the HERV expression level being associated with disease status. Furthermore, some HERV-associated single nucleotide polymorphisms (SNPs), such as rs662139 T/C in a 3-kb region of Xq22.3 containing a HERV-W env locus, and rs391745, upstream of the HERV-Fc1 locus on the X chromosome, are associated with MS susceptibility, while a negative association has been reported with SNPs in the tripartite motif-containing (TRIM) protein-encoding genes TRIM5 and TRIM22. Factors affecting HERV transcription include immune activation and inflammation, since HERV promoter regions possess binding sites for related transcription factors; oxidative stress, with oxidation of guanine to 8-oxoguanine and conversion of cytosine to 5-hydroxymethylcytosine preventing binding of methyl groups transferred by DNA methyltransferases; oxidative stress also inhibits the activity of deacetylases, thereby favouring the acetylation of histone lysine residues favouring gene expression; interferon beta; natalizumab treatment; impaired epigenetic regulation; and the sex of patients.

The Brain-Intestinal Mucosa-Appendix- Microbiome-Brain Loop

The brain and the gut are connected from early fetal life. The mother's exposure to microbial molecules is thought to exert in utero developmental effects on the fetus. These effects could importantly underpin the groundwork for subsequent pathophysiological mechanisms for achieving immunological tolerance and metabolic equilibrium post birth, events that continue through to 3-4 years of age. Furthermore, it is understood that the microbiome promotes cues that instruct the neonate's mucosal tissues and skin in the language of molecular and cellular biology. Post birth mucosal lymphoid tissue formation and maturation (most probably including the vermiform appendix) is microbiota-encouraged co-establishing the intestinal microbiome with a developing immune system. Intestinal mucosal tissue maturation loops the brain-gut-brain and is postulated to influence mood dispositions via shifts in the intestinal microbiome phyla. A plausible appreciation is that dysregulated pro-inflammatory signals from intestinal resident macrophages could breach the loop by providing adverse mood signals via vagus nerve afferents to the brain. In this commentary, we further suggest that the intestinal resident macrophages act as an upstream traffic controller of translocated microbes and metabolites in order to maintain local neuro-endocrine-immunological equilibrium. When macrophages are overwhelmed through intestinal microbiome and intestinal epithelial cell dysbiosis, pro-inflammatory signals are sustained, which may then lead to mood disorders. The administration of probiotics as an adjunctive medicine co-administered with antidepressant medications in improving depressed mood may have biological and clinical standing.