n-3 fatty acids prevent impairment of neurogenesis and synaptic plasticity in B-cell activating factor (BAFF) transgenic mice

Emerging biologic frontiers for Sjogren's syndrome: Unveiling novel approaches with emphasis on extra glandular pathology

Primary Sjögren's Syndrome (pSS) is a complex autoimmune disorder characterized by exocrine gland dysfunction, leading to dry eyes and mouth. Despite growing interest in biologic therapies for pSS, FDA approval has proven challenging due to trial complications. This review addresses the absence of a molecular-target-based approach to biologic therapy development and highlights novel research on drug targets and clinical trials. A literature search identified potential pSS treatment targets and recent advances in molecular understanding. Overlooking extraglandular symptoms like fatigue and depression is a notable gap in trials. Emerging biologic agents targeting cytokines, signal pathways, and immune responses have proven efficacy. These novel therapies could complement existing methods for symptom alleviation. Improved grading systems accounting for extraglandular symptoms are needed. The future of pSS treatment may involve gene, stem-cell, and tissue-engineering therapies. This narrative review offers insights into advancing pSS management through innovative biologic interventions.

How fish consumption prevents the development of Major Depressive Disorder? A comprehensive review of the interplay between n-3 PUFAs, LTP and BDNF

MDD (major depressive disorder) is a highly prevalent mental disorder with a complex etiology involving behavioral and neurochemical factors as well as environmental stress. The interindividual variability in response to stress stimuli may be explained by processes such as long-term potentiation (LTP) and long-term depression (LTD). LTP can be described as the strengthening of synaptic transmission, which translates into more efficient cognitive performance and is regulated by brain-derived neurotrophic factor (BDNF), a protein responsible for promoting neural growth. It is found in high concentrations in the hippocampus, a part of the limbic system which is far less active in people with MDD. Omega-3 fatty acids like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) not only contribute to structural and antioxidative functions but are essential for the maintenance of LTP and stable BDNF levels. This review explores the mechanisms and potential roles of omega-3 fatty acids in the prevention of MDD.

Lessons from Animal Models in Sjögren's Syndrome

Primary Sjögren's syndrome (pSS) is a connective tissue disease characterized by a wide spectrum of clinical features, extending from a benign glandular disease to an aggressive systemic disorder and/or lymphoma. The pathogenesis of Sjögren's syndrome (SS) is not completely understood, but it is assumed that pathogenesis of SS is multifactorial. The studies based on the animal models of SS provided significant insight in SS disease pathogenesis and management. The aim of this review is to summarize current studies on animal models with primary SS-like symptoms and discuss the impact of these studies on better understanding pathogenesis and management of Sjögren's syndrome. Databases PubMed, Web of Science, Scopus and Cochrane library were searched for summarizing studies on animal models in SS. Available data demonstrate that animal models are highly important for our understanding of SS disease.

The Future of Targeted Treatment of Primary Sjögren's Syndrome: A Focus on Extra-Glandular Pathology

Primary Sjögren's syndrome (pSS) is a chronic, systemic autoimmune disease defined by exocrine gland hypofunction resulting in dry eyes and dry mouth. Despite increasing interest in biological therapies for pSS, achieving FDA-approval has been challenging due to numerous complications in the trials. The current literature lacks insight into a molecular-target-based approach to the development of biological therapies. This review focuses on novel research in newly defined drug targets and the latest clinical trials for pSS treatment. A literature search was conducted on ClinicalTrials.gov using the search term "Primary Sjögren's syndrome". Articles published in English between 2000 and 2021 were included. Our findings revealed potential targets for pSS treatment in clinical trials and the most recent advances in understanding the molecular mechanisms underlying the pathogenesis of pSS. A prominent gap in current trials is in overlooking the treatment of extraglandular symptoms such as fatigue, depression, and anxiety, which are present in most patients with pSS. Based on dryness and these symptom-directed therapies, emerging biological agents targeting inflammatory cytokines, signal pathways, and immune reaction have been studied and their efficacy and safety have been proven. Novel therapies may complement existing non-pharmacological methods of alleviating symptoms of pSS. Better grading systems that add extraglandular symptoms to gauge disease activity and severity should be created. The future of pSS therapies may lie in gene, stem-cell, and tissue-engineering therapies.

Vitamin D and Depressive Symptoms in Adults with Multiple Sclerosis: A Scoping Review

BACKGROUND

Vitamin D deficiency has been correlated with Multiple Sclerosis (MS) risk and disease activity. There is some controversy as to whether vitamin D could have an impact on depressive symptoms in people with MS (pwMS). The aim of this scoping review was to evaluate the association between vitamin D status and depressive symptoms in pwMS.

METHODS

We searched databases to include studies published up to March 2021 to provide an overview of the available evidence on the correlation between vitamin D status and depressive symptoms in pwMS. The eligibility criteria were as follows: studies evaluating the use of vitamin D measurement on depressive symptoms in patients suffering from MS, including randomized and non-randomized studies; studies written in English; and studies exploring an adult population over the age of 18.

RESULTS

Eleven studies met our inclusion criteria: two of them were abstracts only; the majority were cross-sectional studies; two were prospective longitudinal studies; one was a retrospective cohort study; and one was a randomized placebo-controlled trial (RCT). Of the eleven studies selected, seven showed a potential correlation between low vitamin D levels and depressive symptoms.

CONCLUSION

Future RCT studies should include patients with greater severity of depressive symptoms and should consider confounding factors such as sun exposure and seasonal variation of vitamin D.

Influencing factors of depressive symptoms in patients with malignant tumour

OBJECTIVE

To assess the influencing factors of depressive symptoms in malignant tumour patients.

METHODS

Participants were 2079 inpatients with malignant tumour (1291: depressive symptoms; 788 no depressive symptoms). Univariable and multivariable logistic regression were used to evaluate sociodemographic and clinical factors influencing depressive symptoms.

RESULTS

Risk factors were family income ≤5000 yuan (odds ratio [OR]: 4.966, 95% confidence interval [CI]: 2.938-8.395) and 5001-10,000 yuan (OR: 3.111, 95% CI: 1.840-5.260); Karnofsky Performance Status of 70 (OR: 2.783, 95% CI: 1.281-6.042) and 80 (OR: 1.834, 95% CI: 1.139-2.953); disease course ≤1 year; palliative treatment (OR: 2.288, 95% CI: 1.292-4.055); progressive disease (OR: 1.876, 95% CI: 1.284-2.739); pain (OR: 1.973, 95% CI: 1.555-2.505); cancer type: lung (OR: 3.199, 95% CI: 1.938-5.279), oesophagus (OR: 3.288, 95% CI: 1.673-6.464), cervix (OR: 1.542, 95% CI: 1.056-2.253) and partial knowledge of disease condition (OR: 2.366, 95% CI: 1.653-3.385). Return to work (OR: 0.503, 95% CI: 0.348-0.727) and physical exercise (OR: 0.437, 95% CI: 0.347-0.551) were protective against depressive symptoms.

CONCLUSIONS

Several factors affected depressive symptoms in malignant tumour patients, including income, disease type and course, palliative treatment, return to work and physical exercise.

Serum levels of n-3 and n-6 polyunsaturated fatty acids in patients with systemic lupus erythematosus and their association with disease activity: a pilot study

Objective: Polyunsaturated fatty acids (PUFAs) may modulate the inflammatory process in systemic autoimmune diseases, including systemic lupus erythematosus (SLE). The aim of this study was to assess the serum concentrations of essential 18-carbon PUFAs and their long-chain derivatives in patients with SLE and healthy controls, and to analyse their associations with laboratory and clinical features of the disease.Method: n-6 and n-3 PUFA composition was assessed in the sera of 30 SLE patients and 20 healthy controls using gas chromatography-mass spectrometry. We investigated the associations between PUFAs and disease activity measured with Systemic Lupus Erythematosus Activity Index (SLEDAI) scores, erythrocyte sedimentation rate, C-reactive protein, complement C3 and C4 concentrations, anti-nuclear antibody (ANA) titre, anti-double-stranded DNA (anti-dsDNA) antibody concentration, and medications.Results: Serum linoleic acid (LA) and α-linolenic acid concentrations were significantly higher in SLE patients compared with healthy controls. LA concentration correlated positively with the ANA titre and corticosteroid doses; eicosapentaenoic acid (EPA) and docosahexaenoic acid correlated inversely with anti-dsDNA antibody concentration. Patients treated with immunosuppressants had significantly lower concentrations of LA, arachidonic acid, and EPA.Conclusion: Both n-6 and n-3 PUFA precursors can participate in the inflammatory process in SLE patients. The mechanism of the PUFA metabolism disturbance needs further exploration.

Hypericum perforatum extract and hyperforin inhibit the growth of neurotropic parasite Toxoplasma gondii and infection-induced inflammatory responses of glial cells in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Hypericum perforatum L. has been widely used as a natural antidepressant. However, it is unknown whether it is effective in treating infection-induced neuropsychiatric disorders.

AIM OF THE STUDY

In order to evaluate the effectiveness of H. perforatum against infection with neurotropic parasite Toxoplasma gondii, which has been linked to neuropsychiatric disorders, this study investigated the anti-Toxoplasma activity using in vitro models.

MATERIALS AND METHODS

Dried alcoholic extracts were prepared from three Hypericum species: H. perforatum, H. erectum, and H. ascyron. H. perforatum extract was further separated by solvent-partitioning. Hyperforin and hypericin levels in the extracts and fractions were analyzed by high resolution LC-MS. Anti-Toxoplasma activities were tested in vitro, using cell lines (Vero and Raw264), murine primary mixed glia, and primary neuron-glia. Toxoplasma proliferation and stage conversion were analyzed by qPCR. Infection-induced damages to the host cells were analyzed by Sulforhodamine B cytotoxicity assay (Vero) and immunofluorescent microscopy (neurons). Infection-induced inflammatory responses in glial cells were analysed by qPCR and immunofluorescent microscopy.

RESULTS

Hyperforin was identified only in H. perforatum among the three tested species, whereas hypericin was present in H. perforatum and H. erectum. H. perforatum extract and hyperforin-enriched fraction, as well as hyperforin, exhibited significant anti-Toxoplasma property as well as inhibitory activity against infection-induced inflammatory responses in glial cells. In addition, H. perforatum-derived hyperforin-enriched fraction restored neuro-supportive environment in mixed neuron-glia culture.

CONCLUSIONS

H. perforatum and its major constituent hyperforin are promising anti-Toxoplasma agents that could potentially protect neurons and glial cells against infection-induced damages. Further study is warranted to establish in vivo efficacy.

Clearing the fog: a review of the effects of dietary omega-3 fatty acids and added sugars on chemotherapy-induced cognitive deficits

Cancer treatments such as chemotherapy have been an important part of extending survival in women diagnosed with breast cancer. However, chemotherapy can cause potentially toxic side effects in the brain that impair memory, verbal fluency, and processing speed in up to 30% of women treated. Women report that post-chemotherapy cognitive deficits negatively impact quality of life and may last up to ten years after treatment. Mechanisms underlying these cognitive impairments are not fully understood, but emerging evidence suggests that chemotherapy induces structural changes in the brain, produces neuroinflammation, and reduces adult hippocampal neurogenesis. Dietary approaches that modify inflammation and neurogenesis are promising strategies for reducing chemotherapy-induced cognitive deficits in breast cancer survivors. In this review, we describe the cognitive and neuronal side effects associated with commonly used chemotherapy treatments for breast cancer, and we focus on the often opposing actions of omega-3 fatty acids and added sugars on cognitive function, neuroinflammation, and adult hippocampal neurogenesis. Omega-3 fatty acids administered concurrently with doxorubicin chemotherapy have been shown to prevent depressive-like behaviors and reduce neuroinflammation, oxidative stress, and neural apoptosis in rodent models. In contrast, diets high in added sugars may interact with n-3 FAs to diminish their anti-inflammatory activity or act independently to increase neuroinflammation, reduce adult hippocampal neurogenesis, and promote cognitive deficits. We propose that a diet rich in long-chain, marine-derived omega-3 fatty acids and low in added sugars may be an ideal pattern for preventing or alleviating neuroinflammation and oxidative stress, thereby protecting neurons from the toxic effects of chemotherapy. Research testing this hypothesis could lead to the identification of modifiable dietary choices to reduce the long-term impact of chemotherapy on the cognitive functions that are important to quality of life in breast cancer survivors.

Exploring BAFF: its expression, receptors and contribution to the immunopathogenesis of Sjögren's syndrome

SS is an autoimmune condition characterized by exocrine gland destruction, autoantibody production, immune complex deposition and systemic complications associated with lymphocytic infiltration of many organs. Genetic, environmental and viral factors play a role in disease aetiology, however, the exact mechanisms driving the immunopathogenesis of SS remain uncertain. Here we discuss a role for B cell activating factor (BAFF), whereby B cell hyperactivity and increased BAFF secretion observed in patients and animal models of the disease can be explained by the altered expression of cell-specific BAFF/BAFF receptor (BAFF-R) variants in several immune cell types. Understanding the role of BAFF/BAFF-R heterogeneity in SS pathogenesis could help to facilitate new treatment strategies for patients.

N-3 polyunsaturated fatty acids in animal models with neuroinflammation: An update

Neuroinflammation is a characteristic of a multitude of neurological and psychiatric disorders. Modulating inflammatory pathways offers a potential therapeutic target in these disorders. Omega-3 polyunsaturated fatty acids have anti-inflammatory and pro-resolving properties in the periphery, however, their effect on neuroinflammation is less studied. This review summarizes 61 animal studies that tested the effect of omega-3 polyunsaturated fatty acids on neuroinflammatory outcomes in vivo in various models including stroke, spinal cord injury, aging, Alzheimer's disease, Parkinson's disease, lipopolysaccharide and IL-1β injections, diabetes, neuropathic pain, traumatic brain injury, depression, surgically induced cognitive decline, whole body irradiation, amyotrophic lateral sclerosis, N-methyl-D-aspartate-induced excitotoxicity and lupus. The evidence presented in this review suggests anti-neuroinflammatory properties of omega-3 polyunsaturated fatty acids, however, it is not clear by which mechanism omega-3 polyunsaturated fatty acids exert their effect. Future research should aim to isolate the effect of omega-3 polyunsaturated fatty acids on neuroinflammatory signaling in vivo and elucidate the mechanisms underlying these effects.

Effects of diet on brain plasticity in animal and human studies: mind the gap

Dietary interventions have emerged as effective environmental inducers of brain plasticity. Among these dietary interventions, we here highlight the impact of caloric restriction (CR: a consistent reduction of total daily food intake), intermittent fasting (IF, every-other-day feeding), and diet supplementation with polyphenols and polyunsaturated fatty acids (PUFAs) on markers of brain plasticity in animal studies. Moreover, we also discuss epidemiological and intervention studies reporting the effects of CR, IF and dietary polyphenols and PUFAs on learning, memory, and mood. In particular, we evaluate the gap in mechanistic understanding between recent findings from animal studies and those human studies reporting that these dietary factors can benefit cognition, mood, and anxiety, aging, and Alzheimer's disease-with focus on the enhancement of structural and functional plasticity markers in the hippocampus, such as increased expression of neurotrophic factors, synaptic function and adult neurogenesis. Lastly, we discuss some of the obstacles to harnessing the promising effects of diet on brain plasticity in animal studies into effective recommendations and interventions to promote healthy brain function in humans. Together, these data reinforce the important translational concept that diet, a modifiable lifestyle factor, holds the ability to modulate brain health and function.

Fatting the brain: a brief of recent research

Fatty acids are of paramount importance to all cells, since they provide energy, function as signaling molecules, and sustain structural integrity of cellular membranes. In the nervous system, where fatty acids are found in huge amounts, they participate in its development and maintenance throughout life. Growing evidence strongly indicates that fatty acids in their own right are also implicated in pathological conditions, including neurodegenerative diseases, mental disorders, stroke, and trauma. In this review, we focus on recent studies that demonstrate the relationships between fatty acids and function and dysfunction of the nervous system. Fatty acids stimulate gene expression and neuronal activity, boost synaptogenesis and neurogenesis, and prevent neuroinflammation and apoptosis. By doing so, they promote brain development, ameliorate cognitive functions, serve as anti-depressants and anti-convulsants, bestow protection against traumatic insults, and enhance repairing processes. On the other hand, unbalance between different fatty acid families or excess of some of them generate deleterious side effects, which limit the translatability of successful results in experimental settings into effective therapeutic strategies for humans. Despite these constraints, there exists realistic evidence to consider that nutritional therapies based on fatty acids can be of benefit to several currently incurable nervous system diseases.

Impact of a multi-nutrient diet on cognition, brain metabolism, hemodynamics, and plasticity in apoE4 carrier and apoE knockout mice

Lipid metabolism and genetic background together strongly influence the development of both cardiovascular and neurodegenerative diseases like Alzheimer's disease (AD). A non-pharmacological way to prevent the genotype-induced occurrence of these pathologies is given by dietary behavior. In the present study, we tested the effects of long-term consumption of a specific multi-nutrient diet in two models for atherosclerosis and vascular risk factors in AD: the apolipoprotein ε4 (apoE4) and the apoE knockout (apoE ko) mice. This specific multi-nutrient diet was developed to support neuronal membrane synthesis and was expected to contribute to the maintenance of vascular health. At 12 months of age, both genotypes showed behavioral changes compared to control mice and we found increased neurogenesis in apoE ko mice. The specific multi-nutrient diet decreased anxiety-related behavior in the open field, influenced sterol composition in serum and brain tissue, and increased the concentration of omega-3 fatty acids in the brain. Furthermore, we found that wild-type and apoE ko mice fed with this multi-nutrient diet showed locally increased cerebral blood volume and decreased hippocampal glutamate levels. Taken together, these data suggest that a specific dietary intervention has beneficial effects on early pathological consequences of hypercholesterolemia and vascular risk factors for AD.

The deficit of lipid in cultured cells contrasted with clinical lipidomics

Cells grown in culture are frequently employed to model lipid metabolism in vivo. There are reasons of convenience for this but examination of the lipidome of cultured cells and their metabolic responses to lipid supplementation give cause to indicate disparity with their counterparts in living animals. The reason is mainly that homeostatic regulation is exercised in animals supplied with an adequate diet in which the adipose tissue and liver represent plentiful sources of lipid integrated via inter-organ collaboration and able to buffer transient fluctuations in dietary lipid and essential fatty acids (EFAs). Moreover, conventional culture media are generally deficient in total lipids as well as essential EFAs. Cultured cells exposed to high glucose concentrations and lipid deficit typically manifest accelerated rates of lipogenesis evidenced by high rates of de novo FA biosynthesis. A more realistic model may be obtained by increasing supplements of lipid especially enriched in essential EFAs in the growth medium. Increasing concentrations of ω3 FAs, in particular, attenuate the rate of de novo lipogenesis. The improvement of cell culture models for pharmacological screening of drug-candidates targeting lipid or glucose metabolism is highlighted.

Relationships between dietary macronutrients and adult neurogenesis in the regulation of energy metabolism

Of the environmental factors which have an impact on body weight, nutrients are most influential. Within normal limits, hypothalamic and related neuronal populations correct perturbations in energy metabolism, to return the body to its nutritional set-point, either through direct response to nutrients or indirectly via peripheral appetite signals. Excessive intake of certain macronutrients, such as simple carbohydrates and SFA, can lead to obesity and attendant metabolic dysfunction, also reflected in alterations in structural plasticity, and, intriguingly,neurogenesis, in some of these brain regions. Neurogenesis, previously thought to occur only in the embryo, is now known to take place in the adult brain, dependent on numerous stimulating and inhibiting factors, including dietary components. Because of classic associations between neurogenesis and the hippocampus, in learning and cognition, this brain region has also been the focus of attention in the study of links between diet and neurogenesis. Recently, however, a more complete picture of this relationship has been building: not only has the hypothalamus been shown to satisfy the criteria for a neurogenic niche, but appetite-related mediators, including circulating hormones, such as leptin and ghrelin, pro-inflammatory cytokines and the endocannabinoid intracellular messengers, are also being examined for their potential role in mediating neurogenic responses to macronutrients. The present review draws together these observations and investigates whether n-3 PUFA may exert their attenuating effects on body weight through the stimulation of adult neurogenesis. Exploration of the effects of nutraceuticals on neurogenic brain regions may encourage the development of new rational therapies in the fight against obesity.

Nutrition, adult hippocampal neurogenesis and mental health

INTRODUCTION

Over the last 8 years, emerging studies bridging the gap between nutrition and mental health have resolutely established that learning and memory abilities as well as mood can be influenced by diet. However, the mechanisms by which diet modulates mental health are still not well understood. Sources of data In this article, a review of the literature was conducted using PubMed to identify studies that provide functional implications of adult hippocampal neurogenesis (AHN) and its modulation by diet.

AREAS OF AGREEMENT

One of the brain structures associated with learning and memory as well as mood is the hippocampus. Importantly, the hippocampus is one of the two structures in the adult brain where the formation of newborn neurons, or neurogenesis, persists.

AREAS OF CONTROVERSY

The exact roles of these newborn neurons in learning, memory formation and mood regulation remain elusive.

GROWING POINTS

Nevertheless, there has been accumulating evidence linking cognition and mood to neurogenesis occurring in the adult hippocampus. Therefore, modulation of AHN by diet emerges as a possible mechanism by which nutrition impacts on mental health.

AREAS TIMELY FOR DEVELOPING RESEARCH

This area of investigation is new and needs attention because a better understanding of the neurological mechanisms by which nutrition affect mental health may lead to novel dietary approaches for disease prevention, healthier ageing and discovery of new therapeutic targets for mental illnesses.