Physical Exercise Attenuates Experimental Autoimmune Encephalomyelitis by Inhibiting Peripheral Immune Response and Blood-Brain Barrier Disruption

Impacts of Nutlin-3a and exercise on murine double minute 2-enriched glioma treatment

JOURNAL/nrgr/04.03/01300535-202504000-00029/figure1/v/2024-07-06T104127Z/r/image-tiff Recent research has demonstrated the impact of physical activity on the prognosis of glioma patients, with evidence suggesting exercise may reduce mortality risks and aid neural regeneration. The role of the small ubiquitin-like modifier (SUMO) protein, especially post-exercise, in cancer progression, is gaining attention, as are the potential anti-cancer effects of SUMOylation. We used machine learning to create the exercise and SUMO-related gene signature (ESLRS). This signature shows how physical activity might help improve the outlook for low-grade glioma and other cancers. We demonstrated the prognostic and immunotherapeutic significance of ESLRS markers, specifically highlighting how murine double minute 2 (MDM2), a component of the ESLRS, can be targeted by nutlin-3. This underscores the intricate relationship between natural compounds such as nutlin-3 and immune regulation. Using comprehensive CRISPR screening, we validated the effects of specific ESLRS genes on low-grade glioma progression. We also revealed insights into the effectiveness of Nutlin-3a as a potent MDM2 inhibitor through molecular docking and dynamic simulation. Nutlin-3a inhibited glioma cell proliferation and activated the p53 pathway. Its efficacy decreased with MDM2 overexpression, and this was reversed by Nutlin-3a or exercise. Experiments using a low-grade glioma mouse model highlighted the effect of physical activity on oxidative stress and molecular pathway regulation. Notably, both physical exercise and Nutlin-3a administration improved physical function in mice bearing tumors derived from MDM2-overexpressing cells. These results suggest the potential for Nutlin-3a, an MDM2 inhibitor, with physical exercise as a therapeutic approach for glioma management. Our research also supports the use of natural products for therapy and sheds light on the interaction of exercise, natural products, and immune regulation in cancer treatment.

Research progress on the role and inhibitors of Keap1 signaling pathway in inflammation

Inflammation is a protective mechanism against endogenous and exogenous pathogens. It is a typical feature of numerous chronic diseases and their complications. Keap1 is an essential target in oxidative stress and inflammatory diseases. Among them, the Keap1-Nrf2-ARE pathway (including Keap1-Nrf2-HO-1) is the most significant pathway of Keap1 targets, which participates in the control of inflammation in multiple organs (including renal inflammation, lung inflammation, liver inflammation, neuroinflammation, etc.). Identifying new Keap1 inhibitors is crucial for new drug discovery. However, most drugs have specificity issues as they covalently bind to cysteine residues of Keap1, causing off-target effects. Therefore, direct inhibition of Keap1-Nrf2 PPIs is a new research idea. Through non-electrophilic and non-covalent binding, its inhibitors have better specificity and ability to activate Nrf2, and targeting therapy against Keap1-Nrf2 PPIs has become a new method for drug development in chronic diseases. This review summarizes the members and downstream genes of the Keap1-related pathway and their roles in inflammatory disease models. In addition, we summarize all the research progress of anti-inflammatory drugs targeting Keap1 from 2010 to 2024, mainly describing their biological functions, molecular mechanisms of action, and therapeutic roles in inflammatory diseases.

The relevance of BDNF for neuroprotection and neuroplasticity in multiple sclerosis

Background

Neuroplasticity as a mechanism to overcome central nervous system injury resulting from different neurological diseases has gained increasing attention in recent years. However, deficiency of these repair mechanisms leads to the accumulation of neuronal damage and therefore long-term disability. To date, the mechanisms by which remyelination occurs and why the extent of remyelination differs interindividually between multiple sclerosis patients regardless of the disease course are unclear. A member of the neurotrophins family, the brain-derived neurotrophic factor (BDNF) has received particular attention in this context as it is thought to play a central role in remyelination and thus neuroplasticity, neuroprotection, and memory.

Objective

To analyse the current literature regarding BDNF in different areas of multiple sclerosis and to provide an overview of the current state of knowledge in this field.

Conclusion

To date, studies assessing the role of BDNF in patients with multiple sclerosis remain inconclusive. However, there is emerging evidence for a beneficial effect of BDNF in multiple sclerosis, as studies reporting positive effects on clinical as well as MRI characteristics outweighed studies assuming detrimental effects of BDNF. Furthermore, studies regarding the Val66Met polymorphism have not conclusively determined whether this is a protective or harmful factor in multiple sclerosis, but again most studies hypothesized a protective effect through modulation of BDNF secretion and anti-inflammatory effects with different effects in healthy controls and patients with multiple sclerosis, possibly due to the pro-inflammatory milieu in patients with multiple sclerosis. Further studies with larger cohorts and longitudinal follow-ups are needed to improve our understanding of the effects of BDNF in the central nervous system, especially in the context of multiple sclerosis.

Cellular and molecular mechanisms of the blood-brain barrier dysfunction in neurodegenerative diseases

BACKGROUND

Maintaining the structural and functional integrity of the blood-brain barrier (BBB) is vital for neuronal equilibrium and optimal brain function. Disruptions to BBB performance are implicated in the pathology of neurodegenerative diseases.

MAIN BODY

Early indicators of multiple neurodegenerative disorders in humans and animal models include impaired BBB stability, regional cerebral blood flow shortfalls, and vascular inflammation associated with BBB dysfunction. Understanding the cellular and molecular mechanisms of BBB dysfunction in brain disorders is crucial for elucidating the sustenance of neural computations under pathological conditions and for developing treatments for these diseases. This paper initially explores the cellular and molecular definition of the BBB, along with the signaling pathways regulating BBB stability, cerebral blood flow, and vascular inflammation. Subsequently, we review current insights into BBB dynamics in Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and multiple sclerosis. The paper concludes by proposing a unified mechanism whereby BBB dysfunction contributes to neurodegenerative disorders, highlights potential BBB-focused therapeutic strategies and targets, and outlines lessons learned and future research directions.

CONCLUSIONS

BBB breakdown significantly impacts the development and progression of neurodegenerative diseases, and unraveling the cellular and molecular mechanisms underlying BBB dysfunction is vital to elucidate how neural computations are sustained under pathological conditions and to devise therapeutic approaches.

The Application Potential of the Regulation of Tregs Function by Irisin in the Prevention and Treatment of Immune-Related Diseases

Irisin is a muscle factor induced by exercise, generated through the proteolytic cleavage of the membrane protein fibronectin type III domain-containing protein 5 (FNDC-5). Numerous studies have shown that irisin plays a significant role in regulating glucose and lipid metabolism, inhibiting oxidative stress, reducing systemic inflammatory responses, and providing neuroprotection. Additionally, irisin can exert immunomodulatory functions by regulating regulatory T cells (Tregs). Tregs are a highly differentiated subset of mature T cells that play a key role in maintaining self-immune homeostasis and are closely related to infections, inflammation, immune-related diseases, and tumors. Irisin exerts persistent positive effects on Treg cell functions through various mechanisms, including regulating Treg cell differentiation and proliferation, improving their function, modulating the balance of immune cells, increasing the production of anti-inflammatory cytokines, and enhancing metabolic functions, thereby helping to maintain immune homeostasis and prevent immune-related diseases. As an important myokine, irisin interacts with receptors on the cell membrane, activating multiple intracellular signaling pathways to regulate cell metabolism, proliferation, and function. Although the specific receptor for irisin has not been fully identified, integrins are considered potential receptors. Irisin activates various signaling pathways, including AMPK, MAPK, and PI3K/Akt, through integrin receptors, thereby exerting multiple biological effects. These research findings provide important clues for understanding the mechanisms of irisin's action and theoretical basis for its potential applications in metabolic diseases and immunomodulation. This article reviews the relationship between irisin and Tregs, as well as the research progress of irisin in immune-related diseases such as multiple sclerosis, myasthenia gravis, acquired immune deficiency syndrome, type 1 diabetes, sepsis, and rheumatoid arthritis. Studies have revealed that irisin plays an important role in immune regulation by improving the function of Tregs, suggesting its potential application value in the treatment of immune-related diseases.

Molecular Mechanisms Regulating Vascular Endothelial Permeability

Vascular endothelial cells form a monolayer in the vascular lumen and act as a selective barrier to control the permeability between blood and tissues. To maintain homeostasis, the endothelial barrier function must be strictly integrated. During acute inflammation, vascular permeability temporarily increases, allowing intravascular fluid, cells, and other components to permeate tissues. Moreover, it has been suggested that the dysregulation of endothelial cell permeability may cause several diseases, including edema, cancer, and atherosclerosis. Here, we reviewed the molecular mechanisms by which endothelial cells regulate the barrier function and physiological permeability.

Resistance training modifies of serum levels of matrix metalloproteinase 2 and tissue inhibitor of matrix metalloproteinases in multiple sclerosis women - a randomized controlled trail

The objectives of the present study was to investigate the effects of resistance training (RT) on serum levels of controlling blood-brain barrier (BBB) permeability indices and cognitive performance in MS women (MS-W). In this randomized control trail study (IRCT registration code: IRCT20120912010824N3, 07.09.2023), twenty-five MS-W were randomly divided into sedentary (MS) and resistance exercise (12 weeks/3 times per week/ 60-80% of 1RM) (MS + RT) groups. Fifteen healthy aged-matched women participated as a control group (HCON). The serum level of matrix metalloproteinase-2 (MMP-2), matrix metallopeptidase-9 (MMP-9), tissue metalloproteinase inhibitors-1 (TIMP-1), tissue metalloproteinase inhibitors-2 (TIMP-2), and S100 calcium-binding protein B (S100B) were assessed. In addition, cognitive performance was assessed pre- and post- intervention with the Brief International Cognitive Assessment for MS (BICAMS). A significant reduction in MMP-2, TIMP-2 serum levels, and MMP-2/TIMP-2 ratio were observed in post-test for MS + RT group (p < 0.01) in comparison to the HCON and MS groups; however, no changes were observed in MMP-9, TIMP-1, S100B and MMP-9/TIMP-1 ratio after RT (p > 0.05). The verbal learning was improved in post-test for MS + RT group (p < 0.01), although no change were observed for visuospatial memory and information processing speed (p > 0.05). These findings suggest that resistance training can modify some indices of BBB permeability and improve verbal learning in MS-W. The findings may also be beneficial as a non-pharmacological intervention to reduce inflammation.

The Mechanisms Underlying the Beneficial Impact of Aerobic Training on Cancer-Related Fatigue: A Conceptual Review

Cancer-related fatigue (CRF) is a prevalent and persistent issue affecting cancer patients, with a broad impact on their quality of life even years after treatment completion. The precise mechanisms underlying CRF remain elusive, yet its multifaceted nature involves emotional, physical, and cognitive dimensions. The absence of effective medical treatments has prompted researchers to explore integrative models for potential insights. Notably, physical exercise emerges as a promising strategy for managing CRF and related symptoms, as studies showed a reduction in CRF ranging from 19% to 40%. Current recommendations highlight aerobic training at moderate intensity as beneficial, although questions about a dose-response relationship and the importance of exercise intensity persist. Despite the positive impact of exercise on CRF, the underlying mechanisms remain elusive. This review aims to provide a theoretical model explaining how aerobic exercise may alleviate CRF. Focusing on acute exercise effects, this review delves into the potential influence on peripheral and neural inflammation, immune function dysregulation, and neuroendocrine system disruptions. The objective is to enhance our understanding of the intricate relationship between exercise and CRF, ultimately paving the way for tailored interventions and potential pharmacological treatments for individuals unable to engage in physical exercise.

Irisin: An unveiled bridge between physical exercise and a healthy brain

AIMS

Physical exercise has been widely recognized for its positive effects on health and well-being. Recently, the impact of exercise on the nervous system has gained attention, with evidence indicating improvements in attention, memory, neurogenesis, and the release of "happiness hormones." One potential mediator of these benefits is Irisin, a myokine induced by exercise that can cross the blood-brain barrier, reduce neuroinflammation, and counteract neurodegeneration. The objective of this study is to conduct a systematic review of animal trials to summarize the neuroprotective effects of Irisin injection in mitigating neuroinflammation and neurodegeneration.

MATERIALS AND METHODS

Two independent reviewers screened three databases (PubMed, Embase, and Google Scholar) in November 2022. Animal studies assessing the neuroprotective effects of Irisin in mitigating neuroinflammation or counteracting neurodegeneration were included. The methodological quality of the included studies was assessed using SYRCLE's Risk of Bias tool.

KEY FINDINGS

Twelve studies met the inclusion criteria. Irisin injection in rodents significantly reduced neuroinflammation, cytokine cascades, and neurodegeneration. It also protected neurons from damage and apoptosis, reduced oxidative stress, blood-brain barrier disruption, and neurobehavioral deficits following disease or injury. Various mechanisms were suggested to be responsible for these neuroprotective effects. Most of the included studies presented a low risk of bias based on SYRCLE's Risk of Bias tool. Irisin injection demonstrated the potential to alleviate neuroinflammation and counteract neurodegeneration in rodent models through multiple pathways. However, further research is needed to fully understand its mechanism of action and its potential applications in clinical practice and drug discovery.

The role of platelets in the blood-brain barrier during brain pathology

Platelets play critical roles in maintaining hemostasis. The blood brain barrier (BBB), a significant physical and metabolic barrier, helps maintain physiological stability by limiting transportations between the blood and neural tissues. When the brain undergoes inflammation, tumor, trauma, or bleeding, the platelet responses to help with maintaining BBB homeostasis. In the traditional point of view, activated platelets aggregate to form thrombi which cover the gaps of the blood vessels to protect BBB. However, increasing evidences indicate that platelets may harm BBB by enhancing vascular permeability. Hereby, we reviewed recently published articles with a special focus on the platelet-mediated damage of BBB. Factors released by platelets can induce BBB permeability, which involve platelet-activating factors (PAF), P-selectin, ADP, platelet-derived growth factors (PDGF) superfamily proteins, especially PDGF-AA and PDGF-CC, etc. Platelets can also secrete Amyloid-β (Aβ), which triggers neuroinflammation and downregulates the expression of tight junction molecules such as claudin-5 to damage BBB. Additionally, platelets can form aggregates with neutrophils to release reactive oxygen species (ROS), which can destroy the DNA, proteins, and lipids of endothelial cells (ECs). Moreover, platelets participate in neuroinflammation to affect BBB. Conversely, some of the platelet released factors such as PDGF-BB, protects BBB. In summary, platelets play dual roles in BBB integrity and the related mechanisms are reviewed.

Immunomodulatory effects of exercise in cancer prevention and adjuvant therapy: a narrative review

Successful application of cancer immunotherapy has rekindled hope in cancer patients. However, a number of patients are unresponsive to immunotherapy and related treatments. This unresponsiveness in cancer patients toward different treatment regimens can be mainly attributed to severe immune dysfunction in such patients. Several reports indicate that physical exercise can significantly lead to improved cancer patient outcomes. Since exercise gets immense response from the immune system, it can be utilized to improve immune function. Leukocytes with enhanced functions are substantially mobilized into the circulation by a single bout of intense physical exercise. Chronic physical exercise results in greater muscle endurance and strength and improved cardiorespiratory function. This exercise regime is also useful in improving T-cell abundance and reducing dysfunctional T cells. The current available data strongly justify for future clinical trials to investigate physical exercise use as an adjuvant in cancer therapy; however, optimal parameters using exercise for a defined outcome are yet to be established. The components of the immune system associate with almost every tumorigenesis step. The inter-relationship between inflammation, cancer, and innate immunity has recently gained acceptance; however, the underlying cellular and molecular mechanisms behind this relationship are yet to be solved. Several studies suggest physical exercise-mediated induction of immune cells to elicit anti-tumorigenic effects. This indicates the potential of exercising in modulating the behavior of immune cells to inhibit tumor progression. However, further mechanistic details behind physical exercise-driven immunomodulation and anticancer effects have to be determined. This review aims to summarize and discuss the association between physical exercise and immune function modulation and the potential of exercise as an adjuvant therapy in cancer prevention and treatment.

FGFR2 modulates the Akt/Nrf2/ARE signaling pathway to improve angiotensin II-induced hypertension-related endothelial dysfunction

BACKGROUND

Fibroblast growth factor receptor (FGFR)2 expression was decreased in hypertension patients while its role in hypertension was not explored. This experiment aimed to investigate the expression ofFGFR2 in angiotensin II (Ang II)-induced human umbilical vein endothelial cells (HUVECs) and the role of FGFR2 in improving AngII-induced hypertension-related endothelial dysfunction.

METHODS

AngII-induced HUVECs simulated the hypertension model in vitro. The expression of FGFR2 in Ang II-induced HUVECs and transfected HUVECswas detected by RT-qPCR and western blot. The viability, apoptosis, migration and tube formation ability of Ang II-induced HUVECs were analyzed by Methyl Thiazolyl Tetrazolium (MTT) assay, flow cytometry analysis, wound healing assay and tube formation assay.Detectionof lactate dehydrogenase (LDH), caspase 3, Nitric Oxide (NO) and oxidative stress levels was conducted by assay kits and reactive oxygen species (ROS) level was detected by DCFH-DA assay. The expression of apoptosis-related proteins, protein kinase B(Akt)/nuclear factor E2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway-related proteins, phospho(p)-endothelial nitric oxide synthase (eNOS) and eNOS was determined by western blot.

RESULTS

The expression of FGFR2 was decreased in Ang II-induced HUVECs. FGFR2overexpression increased viability, suppressed apoptosis and oxidative stress, and improve endothelial dysfunction of AngII-induced HUVECs through activating the Akt/Nrf2/ARE signaling pathway. MK-2206 (Akt inhibitor) could weaken the effect of FGFR2overexpression to reduce viability, promote apoptosis and oxidative stress, and aggravate endothelial dysfunction of Ang II-inducedHUVECs.

CONCLUSION

Inconclusion, FGFR2activated the Akt/Nrf2/ARE signaling pathway to improve AngII-induced hypertension-related endothelial dysfunction.

Endurance Exercise Attenuates Established Progressive Experimental Autoimmune Encephalomyelitis and Is Associated with an Amelioration of Innate Immune Responses in NOD Mice

Multiple sclerosis (MS) is a chronic inflammatory autoimmune disease causing axonal degeneration and demyelination. Exercise in mice with active monophasic experimental autoimmune encephalomyelitis (EAE) attenuates disease severity associated with diverse impacts on T cell-mediated immunity. However, studies have so far focused on preventive approaches. In this study, we investigated the impact of endurance exercise on established EAE disease in a model of secondary progressive MS. When the exercise program on motorized running wheels was started at disease manifestation, the disease course was significantly ameliorated. This was associated with a significant decrease in B cell, dendritic cell, and neutrophil cell counts in the central nervous system (CNS). Furthermore, we observed an increased expression of major histocompatibility complex class II (MHC-II) as well as alterations in costimulatory molecule expression in CNS B cells and dendritic cells. In contrast, T cell responses were not altered in the CNS or periphery. Thus, exercise training is capable of attenuating the disease course even in established secondary progressive EAE, potentially via modulation of the innate immune compartment. Further studies are warranted to corroborate our findings and assess the potential of this lifestyle intervention as a complementary therapeutic strategy in secondary progressive MS patients.

Multiple sclerosis and exercise-A disease-modifying intervention of mice or men?

Research suggests that physical exercise can promote an anti-inflammatory and neuroprotective state. If so, increasing or optimizing exercise could be considered a 'disease-modifying intervention' in neuroinflammatory diseases, such as multiple sclerosis (MS). Exercise intervention studies conducted in animal models of MS are promising. Various aerobic and strength training regimes have been shown to delay disease onset and to reduce both the clinical and pathological disease severity in mice. However, fundamental differences between the physiology of animals and humans, the disease states studied, and the timing of exercise intervention are significant. In animal models of MS, most exercise interventions begin before disease initiation and before any clinical sign of disease. In contrast, studies in humans recruit participants on average nearly a decade after diagnosis and often once disability is established. If, as is thought to be the case for disease-modifying treatments, the immunomodulatory effect of exercise decreases with advancing disease duration, current studies may therefore fail to detect the true disease-modifying potential. Clinical studies in early disease cohorts are needed to determine the role of exercise as a disease-modifying intervention for people with MS.

Mechanisms underlying the beneficial effects of physical exercise on multiple sclerosis: focus on immune cells

Multiple sclerosis (MS) is a prevalent neuroimmunological illness that leads to neurological disability in young adults. Although the etiology of MS is heterogeneous, it is well established that aberrant activity of adaptive and innate immune cells plays a crucial role in its pathogenesis. Several immune cell abnormalities have been described in MS and its animal models, including T lymphocytes, B lymphocytes, dendritic cells, neutrophils, microglia/macrophages, and astrocytes, among others. Physical exercise offers a valuable alternative or adjunctive disease-modifying therapy for MS. A growing body of evidence indicates that exercise may reduce the autoimmune responses triggered by immune cells in MS. This is partially accomplished by restricting the infiltration of peripheral immune cells into the central nervous system (CNS) parenchyma, curbing hyperactivation of immune cells, and facilitating a transition in the balance of immune cells from a pro-inflammatory to an anti-inflammatory state. This review provides a succinct overview of the correlation between physical exercise, immune cells, and MS pathology, and highlights the potential benefits of exercise as a strategy for the prevention and treatment of MS.

Physical activity is related to disease severity and fatigue, but not to relapse rate in persons with relapsing remitting multiple sclerosis - a self-reported questionnaire based study

Introduction

Based on theoretical models, physical activity has been introduced as a promoting method to mitigate the disease severity, fatigue and relapse rate in multiple sclerosis. The primary objective of the study was to investigate the relation between self-reported physical activity level and disease severity, fatigue and relapse rate in persons with relapsing remitting multiple sclerosis (RRMS).

Methods

A survey was offered to persons with RRMS from March 2019 to August 2021 (n = 253). Physical activity level, fatigue and disease severity were determined using the Godin Leisure-Time Questionnaire (GLTEQ), the Patient Determined Disease Steps (PDDS) scale and the Fatigue Scale for Motor and Cognitive Functions (FSMC). Additionally, participants' relapse rate was recorded.

Results

Bivariate correlations revealed an inverse relation between physical activity level and PDDS (ρ = -0.279; p < 0.001) as well as between physical activity and FSMC (r = -0.213, p < 0.001), but not between physical activity and relapse rate (r = 0.033, p > 0.05). Multiple linear regression analyses explained 12.6% and 5.2% of the variance of PDDS and FSMC.

Conclusion

Our findings confirm a relation between self-reported physical activity, disease severity and fatigue in persons with RRMS. However, self-reported physical activity level does not seem to affect the annualised relapse rate.

Uncovering the mechanisms of Yi Qi Tong Qiao Pill in the treatment of allergic rhinitis based on Network target analysis

OBJECTIVE

The purpose of this study is to reveal the mechanism of action of Yi Qi Tong Qiao Pill (YQTQP) in the treatment of allergic rhinitis (AR), as well as establish a paradigm for the researches on traditional Chinese medicine (TCM) from systematic perspective.

METHODS

Based on the data collected from TCM-related and disease-related databases, target profiles of compounds in YQTQP were calculated through network-based algorithms and holistic targets of TQTQP was constructed. Network target analysis was performed to explore the potential mechanisms of YQTQP in the treatment of AR and the mechanisms were classified into different modules according to their biological functions. Besides, animal and clinical experiments were conducted to validate our findings inferred from Network target analysis.

RESULTS

Network target analysis showed that YQTQP targeted 12 main pathways or biological processes related to AR, represented by those related to IL-4, IFN-γ, TNF-α and IL-13. These results could be classified into 3 biological modules, including regulation of immune and inflammation, epithelial barrier disorder and cell adhesion. Finally, a series of experiments composed of animal and clinical experiments, proved our findings and confirmed that YQTQP could improve related symptoms of AR, like permeability of nasal mucosa epithelium.

CONCLUSION

A combination of Network target analysis and the experimental validation indicated that YQTQP was effective in the treatment of AR and might provide a new insight on revealing the mechanism of TCM against diseases. Trial registration Name of the registry: Chinese Clinical Trial Registry: Trial registration number: ChiCTR-TRC-13,003,137: Date of registration: Registered 29 March 2013 - Retrospectively registered: URL of trial registry record: https://www.chictr.org.cn/showproj.html?proj=6422 .

Sex-specific effects of voluntary wheel running on behavior and the gut microbiota-immune-brain axis in mice

Physical exercise has been positioned as a promising strategy to prevent and/or alleviate anxiety and depression, but the biological processes associated with its effects on mental health have yet to be entirely determined. Although the prevalence of depression and anxiety in women is about twice that of men, very few studies have examined whether physical exercise could affect mental health differently according to sex. This study examined, in singly-housed mice, the sex-specific effects of voluntary exercise on depressive- and anxiety-like behaviors as well as on different markers along the gut microbiota-immune-brain axis. Male and female C57BL/6N mice had voluntary access to running wheels in their home-cages for 24 days or were left undisturbed in identical home-cages without running wheels. Behaviors were then examined in the open field, splash, elevated plus maze, and tail suspension tests. Gene expression of pro-inflammatory cytokines, microglia activation-related genes, and tight junction proteins was determined in the jejunum and the hippocampus, while microbiota composition and predicted function were verified in cecum contents. Voluntary exercise reduced anxiety-like behaviors and altered grooming patterns in males exclusively. Although the exercise intervention resulted in changes to brain inflammatory activity and to cecal microbiota composition and inferred function in both sexes, reductions in the jejunal expression of pro-inflammatory markers were observed in females only. These findings support the view that voluntary exercise, even when performed during a short period, is beneficial for mental and intestinal health and that its sex-specific effects on behavior could be, at least in part, related to some components of the gut microbiota-immune-brain axis.

Regulation of Redox Profile and Genomic Instability by Physical Exercise Contributes to Neuroprotection in Mice with Experimental Glioblastoma

Glioblastoma (GBM) is an aggressive, common brain cancer known to disrupt redox biology, affecting behavior and DNA integrity. Past research remains inconclusive. To further understand this, an investigation was conducted on physical training's effects on behavior, redox balance, and genomic stability in GBMA models. Forty-seven male C57BL/6J mice, 60 days old, were divided into GBM and sham groups (n = 15, n = 10, respectively), which were further subdivided into trained (Str, Gtr; n = 10, n = 12) and untrained (Sut, Gut; n = 10, n = 15) subsets. The trained mice performed moderate aerobic exercises on a treadmill five to six times a week for a month while untrained mice remained in their enclosures. Behavior was evaluated using open-field and rotarod tests. Post training, the mice were euthanized and brain, liver, bone marrow, and blood samples were analyzed for redox and genomic instability markers. The results indicated increased latency values in the trained GBM (Gtr) group, suggesting a beneficial impact of exercise. Elevated reactive oxygen species in the parietal tissue of untrained GBM mice (Gut) were reduced post training. Moreover, Gtr mice exhibited lower tail intensity, indicating less genomic instability. Thus, exercise could serve as a promising supplemental GBM treatment, modulating redox parameters and reducing genomic instability.

Forced treadmill running modifies gut microbiota with alleviations of cognitive impairment and Alzheimer's disease pathology in 3xTg-AD mice

Physical exercise has been recommended as a non-pharmacologic treatment for delaying the onset or slowing the progression of Alzheimer's disease (AD). The therapeutic potential of exercise training-induced changes in symbiotic gut microbiota against AD neuropathology is not well understood, yet. This study investigated the effects of a 20-week forced treadmill exercise program on the makeup of the gut microbiota, the integrity of the blood-brain barrier (BBB), and the development of AD-like cognitive deficits and neuropathology in triple transgenic AD mice. Our findings show that forced treadmill running causes symbiotic changes in the gut microbiota, such as increased Akkermansia muciniphila and decreased Bacteroides species, as well as increased BBB-related protein expression and reduced AD-like cognitive impairments and neuropathology progression. The current findings of this animal study suggest that the interaction between the gut microbiota and the brain, possibly via the BBB, is responsible for exercise training-induced cognitive benefits and alleviation of AD pathology.

Aged brain and neuroimmune responses to COVID-19: post-acute sequelae and modulatory effects of behavioral and nutritional interventions

Advanced age is one of the significant risk determinants for coronavirus disease 2019 (COVID-19)-related mortality and for long COVID complications. The contributing factors may include the age-related dynamical remodeling of the immune system, known as immunosenescence and chronic low-grade systemic inflammation. Both of these factors may induce an inflammatory milieu in the aged brain and drive the changes in the microenvironment of neurons and microglia, which are characterized by a general condition of chronic inflammation, so-called neuroinflammation. Emerging evidence reveals that the immune privilege in the aging brain may be compromised. Resident brain cells, such as astrocytes, neurons, oligodendrocytes and microglia, but also infiltrating immune cells, such as monocytes, T cells and macrophages participate in the complex intercellular networks and multiple reciprocal interactions. Especially changes in microglia playing a regulatory role in inflammation, contribute to disturbing of the brain homeostasis and to impairments of the neuroimmune responses. Neuroinflammation may trigger structural damage, diminish regeneration, induce neuronal cell death, modulate synaptic remodeling and in this manner negatively interfere with the brain functions.In this review article, we give insights into neuroimmune interactions in the aged brain and highlight the impact of COVID-19 on the functional systems already modulated by immunosenescence and neuroinflammation. We discuss the potential ways of these interactions with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and review proposed neuroimmune mechanisms and biological factors that may contribute to the development of persisting long COVID conditions. We summarize the potential mechanisms responsible for long COVID, including inflammation, autoimmunity, direct virus-mediated cytotoxicity, hypercoagulation, mitochondrial failure, dysbiosis, and the reactivation of other persisting viruses, such as the Cytomegalovirus (CMV). Finally, we discuss the effects of various interventional options that can decrease the propagation of biological, physiological, and psychosocial stressors that are responsible for neuroimmune activation and which may inhibit the triggering of unbalanced inflammatory responses. We highlight the modulatory effects of bioactive nutritional compounds along with the multimodal benefits of behavioral interventions and moderate exercise, which can be applied as postinfectious interventions in order to improve brain health.

Effectiveness of exercise interventions in animal models of multiple sclerosis

Multiple sclerosis (MS) is associated with an impaired immune system that severely affects the spinal cord and brain, and which is marked by progressive inflammatory demyelination. Patients with MS may benefit from exercise training as a suggested course of treatment. The most commonly used animal models of studies on MS are experimental autoimmune/allergic encephalomyelitis (EAE) models. The present review intends to concisely discuss the interventions using EAE models to understand the effectiveness of exercise as treatment for MS patients and thereby provide clear perspective for future research and MS management. For the present literature review, relevant published articles on EAE animal models that reported the impacts of exercise on MS, were extracted from various databases. Existing literature support the concept that an exercise regimen can reduce the severity of some of the clinical manifestations of EAE, including neurological signs, motor function, pain, and cognitive deficits. Further results demonstrate the mechanisms of EAE suppression with information relating to the immune system, demyelination, regeneration, and exercise in EAE. The role for neurotrophic factors has also been investigated. Analyzing the existing reports, this literature review infers that EAE is a suitable animal model that can help researchers develop further understanding and treatments for MS. Besides, findings from previous animal studies supports the contention that exercise assists in ameliorating MS progression.

Protocol for an exploratory, randomised, single-blind clinical trial of aerobic exercise to promote remyelination in multiple sclerosis

INTRODUCTION

There is an urgent need for remyelinating therapies that restore function in people with multiple sclerosis (pwMS). Aerobic exercise is a promising remyelinating strategy because it promotes remyelination in animal models both independently and synergistically with medications. Here, in this study, we present an innovative, randomised, single-blind, clinical trial designed to explore: the relationship between demyelination and mobility (part 1), and if 24 weeks of aerobic exercise promotes remyelination in pwMS (part 2).

METHODS AND ANALYSIS

Sedentary participants (n=60; aged 18-64 years) with stable MS will undergo a baseline visit with the following outcomes to assess associations between demyelination and mobility (part 1): spinal cord demyelination (somatosensory-evoked potentials, SSEPs), mobility (6-Minute Timed Walk, Timed 25-Foot Walk, Timed Up and Go, 9-Hole Peg Test) and patient-reported outcomes (PROs). After baseline testing, participants with significantly prolonged SSEP latency will advance to the clinical exercise trial (part 2) and will be randomised 1:1 to active or control conditions for 24 weeks. The active condition will be aerobic stationary cycling three times per week with graded virtual supervision. The control condition will be monthly virtual MS symptom education groups (six sessions). SSEP latency (remyelination endpoint), mobility outcomes and PROs will be measured at 12 and 24 weeks in all clinical trial participants. A subset of 11 active and 11 control participants will undergo a brain MRI with quantitative T₁ myelin water fraction at baseline and 24 weeks (exploratory remyelination endpoint).

ETHICS AND DISSEMINATION

Ethical approval was obtained from the Oregon Health & Science University Institutional Review Board (#21045). Dissemination of findings will include peer-reviewed publications, conference presentations and media releases. The proposed study will inform the feasibility, study design and sample size for a fully powered clinical trial of aerobic exercise to promote remyelination in pwMS.

TRIAL REGISTRATION NUMBER

NCT04539002.

Trained hypertensive rats exhibit decreased transcellular vesicle trafficking, increased tight junctions' density, restored blood-brain barrier permeability and normalized autonomic control of the circulation

Introduction: Chronic hypertension is accompanied by either blood-brain barrier (BBB) leakage and autonomic dysfunction. There is no consensus on the mechanism determining increased BBB permeability within autonomic areas. While some reports suggested tight junction's breakdown, others indicated the involvement of transcytosis rather than paracellular transport changes. Interestingly, exercise training was able to restore both BBB permeability and autonomic control of the circulation. We sought now to clarify the mechanism(s) governing hypertension- and exercise-induced BBB permeability. Methods: Spontaneously hypertensive rats (SHR) and normotensive controls submitted to 4-week aerobic training (T) or sedentary protocol (S) were chronically cannulated for baseline hemodynamic and autonomic recordings and evaluation of BBB permeability. Brains were harvested for measurement of BBB function (FITC-10 kDa leakage), ultrastructural analysis of BBB constituents (transmission electron microscopy) and caveolin-1 expression (immunofluorescence). Results: In SHR-S the increased pressure, augmented sympathetic vasomotor activity, higher sympathetic and lower parasympathetic modulation of the heart and the reduced baroreflex sensitivity were accompanied by robust FITC-10kDa leakage, large increase in transcytotic vesicles number/capillary, but no change in tight junctions' density within the paraventricular nucleus of the hypothalamus, the nucleus of the solitary tract and the rostral ventrolateral medulla. SHR-T exhibited restored BBB permeability and normalized vesicles counting/capillary simultaneously with a normal autonomic modulation of heart and vessels, resting bradycardia and partial pressure reduction. Caveolin-1 expression ratified the counting of transcellular, not other cytoplasmatic vesicles. Additionally, T caused in both groups significant increases in tight junctions' extension/capillary border. Discussion: Data indicate that transcytosis, not the paracellular transport, is the primary mechanism underlying both hypertension- and exercise-induced BBB permeability changes within autonomic areas. The reduced BBB permeability contributes to normalize the autonomic control of the circulation, which suppresses pressure variability and reduces the occurrence of end-organ damage in the trained SHR. Data also disclose that hypertension does not change but exercise training strengthens the resistance of the paracellular pathway in both strains.

Exercise sustains the hallmarks of health

Exercise has long been known for its active role in improving physical fitness and sustaining health. Regular moderate-intensity exercise improves all aspects of human health and is widely accepted as a preventative and therapeutic strategy for various diseases. It is well-documented that exercise maintains and restores homeostasis at the organismal, tissue, cellular, and molecular levels to stimulate positive physiological adaptations that consequently protect against various pathological conditions. Here we mainly summarize how moderate-intensity exercise affects the major hallmarks of health, including the integrity of barriers, containment of local perturbations, recycling and turnover, integration of circuitries, rhythmic oscillations, homeostatic resilience, hormetic regulation, as well as repair and regeneration. Furthermore, we summarize the current understanding of the mechanisms responsible for beneficial adaptations in response to exercise. This review aimed at providing a comprehensive summary of the vital biological mechanisms through which moderate-intensity exercise maintains health and opens a window for its application in other health interventions. We hope that continuing investigation in this field will further increase our understanding of the processes involved in the positive role of moderate-intensity exercise and thus get us closer to the identification of new therapeutics that improve quality of life.

Exosomal miR-532-5p induced by long-term exercise rescues blood-brain barrier function in 5XFAD mice via downregulation of EPHA4

The breakdown of the blood-brain barrier, which develops early in Alzheimer's disease (AD), contributes to cognitive impairment. Exercise not only reduces the risk factors for AD but also confers direct protection against cognitive decline. However, the exact molecular mechanisms remain elusive, particularly whether exercise can liberate the function of the blood-brain barrier. Here, we demonstrate that long-term exercise promotes the clearance of brain amyloid-β by improving the function of the blood-brain barrier in 5XFAD mice. Significantly, treating primary brain pericytes or endothelial cells with exosomes isolated from the brain of exercised 5XFAD mice improves cell proliferation and upregulates PDGFRβ, ZO-1, and claudin-5. Moreover, exosomes isolated from exercised mice exhibit significant changes in miR-532-5p. Administration or transfection of miR-532-5p to sedentary mice or primary brain pericytes and endothelial cells reproduces the improvement of blood-brain barrier function. Exosomal miR-532-5p targets EPHA4, and accordingly, expression of EphA4 is decreased in exercised mice and miR-532-5p overexpressed mice. A specific siRNA targeting EPHA4 recapitulates the effects on blood-brain barrier-associated cells observed in exercised 5XFAD mice. Overall, our findings suggest that exosomes released by the brain contain a specific miRNA that is altered by exercise and has an impact on blood-brain barrier function in AD.

Neurorehabilitation in Multiple Sclerosis-A Review of Present Approaches and Future Considerations

Multiple sclerosis is an increasingly prevalent disease, representing the leading cause of non-traumatic neurological disease in Europe and North America. The most common symptoms include gait deficits, balance and coordination impairments, fatigue, spasticity, dysphagia and an overactive bladder. Neurorehabilitation therapeutic approaches aim to alleviate symptoms and improve the quality of life through promoting positive immunological transformations and neuroplasticity. The purpose of this study is to evaluate the current treatments for the most debilitating symptoms in multiple sclerosis, identify areas for future improvement, and provide a reference guide for practitioners in the field. It analyzes the most cited procedures currently in use for the management of a number of symptoms affecting the majority of patients with multiple sclerosis, from different training routines to cognitive rehabilitation and therapies using physical agents, such as electrostimulation, hydrotherapy, cryotherapy and electromagnetic fields. Furthermore, it investigates the quality of evidence for the aforementioned therapies and the different tests applied in practice to assess their utility. Lastly, the study looks at potential future candidates for the treatment and evaluation of patients with multiple sclerosis and the supposed benefits they could bring in clinical settings.

Physical activity prevents tumor metastasis through modulation of immune function

Metastasis is responsible for 90% of deaths in cancer patients. Most patients diagnosed with metastatic cancer will die within 5 years. PA is good for health and has become an emerging adjuvant therapy for cancer survivors. Regular moderate exercise substantially lowers the incidence and recurrence of several cancers, alleviates cancer-related adverse events, enhances the efficacy of anti-cancer treatments, and improves the quality of life of cancer patients. Revealing the mechanisms of PA inhibiting tumor metastasis could upgrade our understanding of cancer biology and help researchers explore new therapeutic strategies to improve survival in cancer patients. However, it remains poorly understood how physical activity prevents metastasis by modulating tumor behavior. The immune system is involved in each step of tumor metastasis. From invasion to colonization, immune cells interact with tumor cells to secret cytokines and proteases to remodel the tumor microenvironment. Substantial studies demonstrated the ability of physical activity to induce antitumor effects of immune cells. This provides the possibility that physical activity can modulate immune cells behavior to attenuate tumor metastasis. The purpose of this review is to discuss and summarize the critical link between immune function and exercise in metastasis prevention.

Exercise training alters autoimmune cell invasion into the brain in autoimmune encephalomyelitis

BACKGROUND

The mechanisms by which exercise training (ET) elicits beneficial effects on the systemic immune system and the central nervous system (CNS) in autoimmune neuroinflammation are not fully understood.

OBJECTIVES

To investigate (1) the systemic effects of high-intensity continuous training (HICT) on the migratory potential of autoimmune cells; (2) the direct effects of HICT on blood-brain-barrier (BBB) properties.

METHODS

Healthy mice were subjected to high-intensity continuous training (HICT) by treadmill running. The proteolipid protein (PLP) transfer EAE model was utilized to examine the immunomodulatory effects of training, where PLP-reactive lymph-node cells (LNCs) from HICT and sedentary donor mice were analyzed in vitro and transferred to naïve recipients that developed EAE. To examine neuroprotection, encephalitogenic LNCs from donor mice were transferred into HICT or sedentary recipient mice and the BBB was analyzed.

RESULTS

Transfer of PLP-reactive LNCs obtained from HICT donor mice attenuated EAE severity and inflammation in recipient mice. HICT markedly inhibited very late antigen (VLA)-4 and lymphocyte function-associated antigen (LFA)-1 expression in LNCs. Transfer of encephalitogenic LNCs into HICT recipients resulted in milder EAE and attenuated CNS inflammation. HICT reduced BBB permeability and the expression of intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 in CNS blood vessels.

INTERPRETATION

HICT attenuates EAE development by both immunomodulatory and neuroprotective effects. The reduction in destructive CNS inflammation in EAE is attributed to systemic inhibition of autoreactive cell migratory potential, as well as reduction in BBB permeability, which are associated with reduced VLA-4/VCAM-1 and LFA-1/ICAM-1 interactions.

Physical Training Protects Against Brain Toxicity in Mice Exposed to an Experimental Model of Glioblastoma

Glioma 261 (Gl261) cell-mediated neurotoxicity has been reported in previous studies examining glioblastoma (GBM), and the effects of physical exercise (PE) on this neurotoxicity have been poorly investigated. This study aimed to evaluate the effects of a PE program in animals with experimental GBM. Male C57BL/6J mice were randomized into sham or GBM groups and subjected to a PE program for four weeks. Gl261 cells were administered into the intraventricular region at 48 h after the last exercise session. Body weight, water and feed consumption, and behavior were all evaluated for 21 days followed by euthanasia. The right parietal lobe was removed for the analysis of glial fibrillary acidic protein (GFAP), epidermal growth factor receptor (EGFR), vimentin, C-myc, nuclear factor kappa B (NF-κB), tumor necrosis factor-alpha (TNF-α), interleukin 1 beta (IL-1β), interleukin 6 (IL-6), hydrogen peroxide, the glutathione system, and oxidative damage to proteins. The results revealed changes in the behavioral patterns of the trained animals, and no anatomopathological changes were observed in response to PE training. In contrast, animals with GBM subjected to PE exhibited lower immunoexpression of c-MYC, vimentin, and GFAP. Although experimental GBM altered the redox profile and inflammatory mediators, no significant alterations were observed after PE. In conclusion, our data provide consistent evidence of the relationship between PE and the improvement of tumorigenic parameters against the neurotoxicity of GL261 cells.

Preventive exercise attenuates IL-2-driven mood disorders in multiple sclerosis

BACKGROUND

Elevated levels of specific proinflammatory molecules in the cerebrospinal fluid (CSF) have been associated with disability progression, enhanced neurodegeneration and higher incidence of mood disorders in people with multiple sclerosis (MS). Studies in animal models of MS suggest that preventive exercise may play an immunomodulatory activity, with beneficial effects on both motor deficits and behavioral alterations. Here we explored the impact of lifestyle physical activity on clinical presentation and associated central inflammation in a large group of newly diagnosed patients with MS. Furthermore, we addressed the causal link between exercise-mediated immunomodulation and mood symptoms in the animal setting.

METHODS

A cross-sectional study was conducted on 235 relapsing-remitting MS patients at the time of the diagnosis. Patients were divided into 3 groups ("sedentary", "lifestyle physical activity" and "exercise") according to the level of physical activity in the six months preceding the evaluation. Patients underwent clinical, neuropsychological and psychiatric evaluation, magnetic resonance imaging and lumbar puncture for diagnostic purposes. The CSF levels of proinflammatory and anti-inflammatory cytokines were analyzed and compared with a group of 80 individuals with non-inflammatory and non-degenerative diseases. Behavioral and electrophysiological studies were carried out in control mice receiving intracerebral injection of IL-2 or vehicle. Behavior was also assessed in mice with experimental autoimmune encephalomyelitis (EAE), animal model of MS, reared in standard (sedentary group) or running wheel-equipped (exercise group) cages.

RESULTS

In exercising MS patients, depression and anxiety were reduced compared to sedentary patients. The CSF levels of the interleukin-2 and 6 (IL-2, IL-6) were increased in MS patients compared with control individuals. In MS subjects exercise was associated with normalized CSF levels of IL-2. In EAE mice exercise started before disease onset reduced both behavioral alterations and striatal IL-2 expression. Notably, a causal role of IL-2 in mood disorders was shown. IL-2 administration in control healthy mice induced anxious- and depressive-like behaviors and impaired type-1 cannabinoid (CB1) receptor-mediated neurotransmission at GABAergic synapses, mimicking EAE-induced synaptic dysfunction.

CONCLUSIONS

Our results indicate an immunomodulatory effect of exercise in MS patients, associated with reduced CSF expression of IL-2, which might result in reduced mood disorders. These data suggest that exercise in the early stages may act as a disease-modifying therapy in MS although further longitudinal studies are needed to clarify this issue.

Resistance Training before, during, and after COVID-19 Infection: What Have We Learned So Far?

At the end of 2019, a severe acute respiratory syndrome caused by SARS-CoV-2 started a pandemic, leading to millions of deaths and many important political and social changes. Even in the absence of contamination, the mobility reduction, social distancing and closing of exercise facilities negatively affected physical activity and conditioning, which is associated with muscle atrophy, loss of muscle strength, and reductions in functional capacity. In cases of infection, it has been shown that increased physical capacity is associated with decreased hospitalization and mortality risk. Although millions of people have died from COVID-19, most contaminated individuals survived the infection, but carried different sequelae, such as the severe loss of physical function and a reduced quality of life. Among different physical exercise models that might help to prevent and treat COVID-19-related conditions, resistance training (RT) might be particularly relevant. Among its benefits, RT can be adapted to be performed in many different situations, even with limited space and equipment, and is easily adapted to an individual's characteristics and health status. The current narrative review aims to provide insights into how RT can be used in different scenarios to counteract the negative effects of COVID-19. By doing this, the authors expect to provide insights to help deal with the current pandemic and similar events the world may face in the future.

Exercise Normalized the Hippocampal Renin-Angiotensin System and Restored Spatial Memory Function, Neurogenesis, and Blood-Brain Barrier Permeability in the 2K1C-Hypertensive Mouse

Hypertension is associated with blood-brain barrier alteration and brain function decline. Previously, we established the 2-kidney,1-clip (2K1C) hypertensive mice model by renin-angiotensin system (RAS) stimulating. We found that 2K1C-induced hypertension would impair hippocampus-related memory function and decrease adult hippocampal neurogenesis. Even though large studies have investigated the mechanism of hypertension affecting brain function, there remains a lack of efficient ways to halt this vicious effect. The previous study indicated that running exercise ameliorates neurogenesis and spatial memory function in aging mice. Moreover, studies showed that exercise could normalize RAS activity, which might be associated with neurogenesis impairment. Thus, we hypothesize that running exercise could ameliorate neurogenesis and spatial memory function impairment in the 2K1C-hypertension mice. In this study, we performed 2K1C surgery on eight-weeks-old C57BL/6 mice and put them on treadmill exercise one month after the surgery. The results indicate that running exercise improves the spatial memory and neurogenesis impairment of the 2K1C-mice. Moreover, running exercise normalized the activated RAS and blood-brain barrier leakage of the hippocampus, although the blood pressure was not decreased. In conclusion, running exercise could halt hypertension-induced brain impairment through RAS normalization.

Blood-brain barrier dysfunction in bipolar disorder: Molecular mechanisms and clinical implications

Bipolar disorder (BD) is a severe psychiatric disorder affecting approximately 1-3% of the population and characterized by a chronic and recurrent course of debilitating symptoms. An increasing focus has been directed to discover and explain the function of Blood-Brain Barrier (BBB) integrity and its association with a number of psychiatric disorders; however, there has been limited research in the role of BBB integrity in BD. Multiple pathways may play crucial roles in modulating BBB integrity in BD, such as inflammation, insulin resistance, and alterations of neuronal plasticity. In turn, BBB impairment is hypothesized to have a significant clinical impact in BD patients. Based on the high prevalence of medical and psychiatric comorbidities in BD and a growing body of evidence linking inflammatory and neuroinflammatory mechanisms to the disorder, recent studies have suggested that BBB dysfunction may play a key role in BD's pathophysiology. In this comprehensive narrative review, we aim to discuss studies investigating biological markers of BBB in patients with BD, mechanisms that modulate BBB integrity, their clinical implications on patients, and key targets for future development of novel therapies.

Multimodal Benefits of Exercise in Patients With Multiple Sclerosis and COVID-19

Multiple sclerosis (MS) is a demyelinating disease characterized by plaque formation and neuroinflammation. The plaques can present in various locations, causing a variety of clinical symptoms in patients with MS. Coronavirus disease-2019 (COVID-19) is also associated with systemic inflammation and a cytokine storm which can cause plaque formation in several areas of the brain. These concurring events could exacerbate the disease burden of MS. We review the neuro-invasive properties of SARS-CoV-2 and the possible pathways for the entry of the virus into the central nervous system (CNS). Complications due to this viral infection are similar to those occurring in patients with MS. Conditions related to MS which make patients more susceptible to viral infection include inflammatory status, blood-brain barrier (BBB) permeability, function of CNS cells, and plaque formation. There are also psychoneurological and mood disorders associated with both MS and COVID-19 infections. Finally, we discuss the effects of exercise on peripheral and central inflammation, BBB integrity, glia and neural cells, and remyelination. We conclude that moderate exercise training prior or after infection with SARS-CoV-2 can produce health benefits in patients with MS patients, including reduced mortality and improved physical and mental health of patients with MS.

Neuroprotective effects of strength training in a neuroinflammatory animal model

Background

The preventive role of muscular strength on diminishing neuroinflammation is yet unknown. In this study, the role of the prophylactic muscular strength exercise was investigated in order to verify whether it would diminish cognitive alterations and modify the antioxidant intracellular scenery in an animal neuroinflammatory model in of the CA1 region of the hippocampus.

Methods

The animals received muscular strength training (SE) three times a week for eight weeks. Subsequently, the stereotaxic surgery was performed with an intra-hippocampal infusion of either saline solution (SAL) or lipopolysaccharide (LPS). Next, we performed the behavioral tests: object recognition and social recognition. Then, the animals were euthanized, and their hippocampus and prefrontal cortex were collected. In another moment, we performed the dosage of the antioxidant activity and histological analysis.

Results

The results showed that the muscular strength exercises could show a beneficial prophylactic effect in the cognitive deficiencies caused by acute neuroinflammation. Regarding oxidative stress, there was an increase in catalase enzyme activity (CAT) in the group (SE + LPS) compared to the control groups (p < 0.05). As for the cognitive alterations, there were found in the (SE + LPS) group, diminishing the mnemonic hazard of the discriminative and social memories compared to the control groups (p < 0.05).

Conclusion

We concluded, therefore, that the exercise performed prophylactically presents a protective effect capable of minimizing such mnemonic deficits and increasing catalase enzyme activity in rats that suffered a local neuroinflammatory process in the hippocampus.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12868-022-00708-w.

Fitness, physical activity, and exercise in multiple sclerosis: a systematic review on current evidence for interactions with disease activity and progression

Background

A moderate to high level of physical activity, including regular exercise, represents an established behavioral and rehabilitative approach for persons with multiple sclerosis (pwMS). Although being increasingly proposed to limit disease activity and progression, high-quality evidence is lacking.

Objective

The objective of the study is to provide valuable information for MS clinicians and researchers by systematically evaluating the current state of evidence (i) whether exercise interventions affect established clinical measures of disease activity and progression in pwMS (i.e., EDSS, relapse rate, lesion load, brain volume, MSFC) and (ii) how the physical activity and fitness level interact with these measures.

Methods

Literature search was conducted in MEDLINE, EMBASE, CINAHL, and SPORTDiscus. Evaluation of evidence quality was done based on standards published by The American Academy of Neurology.

Results

It is likely that exercise improves the MSFC score, whereas the EDSS score, lesion load, and brain volume are likely to remain unchanged over the intervention period. It is possible that exercise decreases the relapse rate. Results from cross-sectional studies indicate beneficial effects of a high physical activity or fitness level on clinical measures which, however, is not corroborated by high evidence quality.

Conclusions

A (supportive) disease-modifying effect of exercise in pwMS cannot be concluded. The rather low evidence quality of existing RCTs underlines the need to conduct more well-designed studies assessing different measures of disease activity or progression as primary end points. A major limitation is the short intervention duration of existing studies which limits meaningful exercise-induced effects on most disability measures. Findings from cross-sectional studies are difficult to contextualize regarding clinical importance due to their solely associative character and low evidence quality.

PROSPERO registration number

CRD42020188774.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-021-10935-6.

Physical exercise therapy for autoimmune neuroinflammation: Application of knowledge from animal models to patient care

Physical exercise (PE) impacts various autoimmune diseases. Accordingly, clinical trials demonstrated the safety of PE in multiple sclerosis (MS) patients and indicated beneficial outcomes. There is also an increasing body of research on the beneficial effects of exercise on experimental autoimmune encephalomyelitis (EAE), the animal model of MS, and various mechanisms underlying these effects were suggested. However, despite the documented favorable impact of PE on our health, we still lack a thorough understanding of its effects on autoimmune neuroinflammation and specific guidelines of PE therapy for MS patients are lacking. To that end, current findings on the impact of PE on autoimmune neuroinflammation, both in human MS and animal models are reviewed. The concept of personalized PE therapy for autoimmune neuroinflammation is discussed, and future research for providing biological rationale for clinical trials to pave the road for precise PE therapy in MS patients is described.

A functional cerebral endothelium is necessary to protect against cognitive decline

A vascular insult occurring early in disease onset may initiate cognitive decline leading to dementia, while pharmacological and lifestyle interventions can prevent this progression. Mice with a selective, tamoxifen-inducible deletion of NF-κB essential modulator (Nemo) in brain endothelial cells were studied as a model of vascular cognitive impairment. Groups included NemoFl controls and three NemobeKO groups: One untreated, and two treated with simvastatin or exercise. Social preference and nesting were impaired in NemobeKO mice and were not countered by treatments. Cerebrovascular function was compromised in NemobeKO groups regardless of treatment, with decreased changes in sensory-evoked cerebral blood flow and total hemoglobin levels, and impaired endothelium-dependent vasodilation. NemobeKO mice had increased string vessel pathology, blood-brain barrier disruption, neuroinflammation, and reduced cortical somatostatin-containing interneurons. These alterations were reversed when endothelial function was recovered. Findings strongly suggest that damage to the cerebral endothelium can trigger pathologies associated with dementia and its functional integrity should be an effective target in future therapeutic efforts.

Blood-Spinal Cord Barrier: Its Role in Spinal Disorders and Emerging Therapeutic Strategies

The blood-spinal cord barrier (BSCB) has been long thought of as a functional equivalent to the blood-brain barrier (BBB), restricting blood flow into the spinal cord. The spinal cord is supported by various disc tissues that provide agility and has different local immune responses compared to the brain. Though physiologically, structural components of the BSCB and BBB share many similarities, the clinical landscape significantly differs. Thus, it is crucial to understand the composition of BSCB and also to establish the cause–effect relationship with aberrations and spinal cord dysfunctions. Here, we provide a descriptive analysis of the anatomy, current techniques to assess the impairment of BSCB, associated risk factors and impact of spinal disorders such as spinal cord injury (SCI), amyotrophic lateral sclerosis (ALS), peripheral nerve injury (PNI), ischemia reperfusion injury (IRI), degenerative cervical myelopathy (DCM), multiple sclerosis (MS), spinal cavernous malformations (SCM) and cancer on BSCB dysfunction. Along with diagnostic and mechanistic analyses, we also provide an up-to-date account of available therapeutic options for BSCB repair. We emphasize the need to address BSCB as an individual entity and direct future research towards it.

Therapeutic Effects of Physical Exercise and the Mesenchymal Stem Cell Secretome by Modulating Neuroinflammatory Response in Multiple Sclerosis

Multiple sclerosis (MS) is a neurodegenerative, demyelinating, and chronic inflammatory disease characterized by central nervous system (CNS) lesions that lead to high levels of disability and severe physical and cognitive disturbances. Conventional therapies are not enough to control the neuroinflammatory process in MS and are not able to inhibit ongoing damage to the CNS. Thus, the secretome of mesenchymal stem cells (MSC-S) has been postulated as a potential therapy that could mitigate symptoms and disease progression. We considered that its combination with physical exercise (EX) could induce superior effects and increase the MSC-S effectiveness in this condition. Recent studies have revealed that both EX and MSC-S share similar mechanisms of action that mitigate auto-reactive T cell infiltration, regulate the local inflammatory response, modulate the proinflammatory profile of glial cells, and reduce neuronal damage. Clinical and experimental studies have reported that these treatments in an isolated way also improve myelination, regeneration, promote the release of neurotrophic factors, and increase the recruitment of endogenous stem cells. Together, these effects reduce disease progression and improve patient functionality. Despite these results, the combination of these methods has not yet been studied in MS. In this review, we focus on molecular elements and cellular responses induced by these treatments in a separate way, showing their beneficial effects in the control of symptoms and disease progression in MS, as well as indicating their contribution in clinical fields. In addition, we propose the combined use of EX and MSC-S as a strategy to boost their reparative and immunomodulatory effects in this condition, combining their benefits on synaptogenesis, neurogenesis, remyelination, and neuroinflammatory response. The findings here reported are based on the scientific evidence and our professional experience that will bring significant progress to regenerative medicine to deal with this condition.

Effects of Exercise Training on Neurotrophic Factors and Subsequent Neuroprotection in Persons with Multiple Sclerosis-A Systematic Review and Meta-Analysis

Background: Evidence indicates that exercise holds the potential to counteract neurodegeneration experienced by persons with multiple sclerosis (pwMS), which is in part believed to be mediated through increases in neurotrophic factors. There is a need to summarize the existing evidence on exercise-induced effects on neurotrophic factors alongside neuroprotection in pwMS. Aim: To (1) systematically review the evidence on acute (one session) and/or chronic (several sessions) exercise-induced changes in neurotrophic factors in pwMS and (2) investigate the potential translational link between exercise-induced changes in neurotrophic factors and neuroprotection. Methods: Five databases (Medline, Scopus, Web of Science, Embase, Sport Discus) were searched for randomized controlled trials (RCT) examining the effects of exercise (all modalities included) on neurotrophic factors as well as measures of neuroprotection if reported. The quality of the study designs and the exercise interventions were assessed by use of the validated tool TESTEX. Results: From N = 337 identified studies, N = 14 RCTs were included. While only N = 2 of the identified studies reported on the acute changes in neurotrophic factors, all N = 14 RCTs reported on the chronic effects, with N = 9 studies revealing between-group differences in favor of exercise. This was most prominent for brain-derived neurotrophic factor (BDNF), with between-group differences in favor of exercise being observed in N = 6 out of N = 12 studies. Meta-analyses were applicable for three out of 10 different identified neurotrophic factors and revealed that exercise can improve the chronic levels of BDNF (delta changes; N = 9, ES = 0.78 (0.27; 1.28), p = 0.003, heterogeneity between studies) and potentially also ciliary neurotrophic factor (CNTF) (N = 3, ES = 0.24 (−0.07; 0.54), p = 0.13, no heterogeneity between studies) but not nerve growth factor (NGF) (N = 4, ES = 0.28 (−0.55; 1.11), p = 0.51, heterogeneity between studies). Indicators of neuroprotection (e.g., with direct measures of brain structure assessed by MRI) were assessed in N = 3 of the identified studies only, with N = 2 partly supporting and thus indicating a potential translational link between increases in neurotrophic factors and neuroprotection. Conclusion: The present study reveals that exercise can elicit improvements in chronic levels of BDNF in pwMS, whereas the effects of exercise on chronic levels of other neurotrophic factors and on acute levels of neurotrophic factors in general, along with a potential translational link (i.e., with exercise-induced improvements in neurotropic factors being associated with or even mediating neuroprotection), are sparse and inconclusive. There is a need for more high-quality studies that assess neurotrophic factors (applying comparable methods of blood handling and analysis) concomitantly with neuroprotective outcome measures. Review Registration: PROSPERO (ID: CRD42020177353).

Identification of key genes and pathways associated with resting mast cells in meningioma

BACKGROUND

To identify candidate key genes and pathways related to resting mast cells in meningioma and the underlying molecular mechanisms of meningioma.

METHODS

Gene expression profiles of the used microarray datasets were obtained from the Gene Expression Omnibus (GEO) database. GO and KEGG pathway enrichments of DEGs were analyzed using the ClusterProfiler package in R. The protein-protein interaction network (PPI), and TF-miRNA- mRNA co-expression networks were constructed. Further, the difference in immune infiltration was investigated using the CIBERSORT algorithm.

RESULTS

A total of 1499 DEGs were identified between tumor and normal controls. The analysis of the immune cell infiltration landscape showed that the probability of distribution of memory B cells, regulatory T cells (Tregs), and resting mast cells in tumor samples were significantly higher than those in the controls. Moreover, through WGCNA analysis, the module related to resting mast cells contained 158 DEGs, and KEGG pathway analysis revealed that the DEGs were dominant in the TNF signaling pathway, cytokine-cytokine receptor interaction, and IL-17 signaling pathway. Survival analysis of hub genes related to resting mast cells showed that the risk model was constructed based on 9 key genes. The TF-miRNA- mRNA co-regulation network, including MYC-miR-145-5p, TNFAIP3-miR-29c-3p, and TNFAIP3-hsa-miR-335-3p, were obtained. Further, 36 nodes and 197 interactions in the PPI network were identified.

CONCLUSION

The results of this study revealed candidate key genes, miRNAs, and pathways related to resting mast cells involved in meningioma development, providing potential therapeutic targets for meningioma treatment.

Exercise protects from hippocampal inflammation and neurodegeneration in experimental autoimmune encephalomyelitis

Exercise is increasingly recommended as a supportive therapy for people with Multiple Sclerosis (pwMS). While clinical research has still not disclosed the real benefits of exercise on MS disease, animal studies suggest a substantial beneficial effect on motor disability and pathological hallmarks such as central and peripheral dysregulated immune response. The hippocampus, a core area for memory formation and learning, is a brain region involved in MS pathophysiology. Human and rodent studies suggest that the hippocampus is highly sensitive to the effects of exercise, the impact of which on MS hippocampal damage is still elusive. Here we addressed the effects of chronic voluntary exercise on hippocampal function and damage in experimental autoimmune encephalomyelitis (EAE), animal model of MS. Mice were housed in standard or wheel-equipped cages starting from the day of immunization and throughout the disease course. Although running activity was reduced during the symptomatic phase, exercise significantly ameliorated motor disability. Exercise improved cognition that was assessed through the novel object recognition test and the nest building in presymptomatic and acute stages of the disease, respectively. In the acute phase exercise was shown to prevent EAE-induced synaptic plasticity abnormalities in the CA1 area, by promoting the survival of parvalbumin-positive (PV+) interneurons and by attenuating inflammation. Indeed, exercise significantly reduced microgliosis in the CA1 area, the expression of tumour necrosis factor (TNF) in microglia and, to a lesser extent, the hippocampal level of interleukin 1 beta (IL-1β), previously shown to contribute to aberrant synaptic plasticity in the EAE hippocampus. Notably, exercise exerted a precocious and long-lasting mitigating effect on microgliosis that preceded its neuroprotective action, likely underlying the improved cognitive function observed in both presymptomatic and acute phase EAE mice. Overall, these data provide evidence that regular exercise improves cognitive function and synaptic and neuronal pathology that typically affect EAE/MS brains.

The Role of Nutritional Lifestyle and Physical Activity in Multiple Sclerosis Pathogenesis and Management: A Narrative Review

Studies on the role of nutritional factors and physical activity (PA) in the pathogenesis of multiple sclerosis (MS) go back a long time. Despite the intrinsic difficulty of studying their positive or negative role in MS, the interest of researchers on these topics increased during the last few decades, since the role of diet has been investigated with the perspective of the association with disease-modifying drugs (DMD). The association of DMD, diets, and PA might have an additive effect in modifying disease severity. Among the various diets investigated (low-carbohydrate, gluten-free, Mediterranean, low-fat, fasting-mimicking, and Western diets) only low-carbohydrate, Mediterranean, and fast-mimicking diets have shown both in animal models and in humans a positive effect on MS course and in patient-reported outcomes (PROs). However, the Mediterranean diet is easier to be maintained compared to fast-mimicking and low-carbohydrate diets, which may lead to detrimental side effects requiring careful clinical monitoring. Conversely, the Western diet, which is characterized by a high intake of highly saturated fats and carbohydrates, may lead to the activation of pro-inflammatory immune pathways and is therefore not recommended. PA showed a positive effect both in animal models as well as on disease course and PROs in humans. Training with combined exercises is considered the more effective approach.

The Blood-Brain Barrier: Much More Than a Selective Access to the Brain

The blood-brain barrier is a dynamic structure, collectively referred to as the neurovascular unit. It is responsible for the exchange of blood, oxygen, ions, and other molecules between the peripheral circulation and the brain compartment. It is the main entrance to the central nervous system and as such critical for the maintenance of its homeostasis. Dysfunction of the blood-brain barrier is a characteristic of several neurovascular pathologies. Moreover, physiological changes, environmental factors, nutritional habits, and psychological stress can modulate the tightness of the barrier. In this contribution, we summarize our current understanding of structure and function of this important component of the brain. We also describe the neurological deficits associated with its damage. A special emphasis is placed in the effect of the exposure to xenobiotics and pollutants in the permeability of the barrier. Finally, current protective strategies as well as the culture models to study this fascinating structure are discussed.

Blood-Brain Barrier Dysfunction in the Pathogenesis of Major Depressive Disorder

Major depression represents a complex and prevalent psychological disease that is characterized by persistent depressed mood, impaired cognitive function and complicated pathophysiological and neuroendocrine alterations. Despite the multifactorial etiology of depression, one of the most recent factors to be identified as playing a critical role in the development of depression is blood-brain barrier (BBB) disruption. The occurrence of BBB integrity disruption contributes to the disturbance of brain homeostasis and leads to complications of neurological diseases, such as stroke, chronic neurodegenerative disorders, neuroinflammatory disorders. Recently, BBB associated tight junction disruption has been shown to implicate in the pathophysiology of depression and contribute to increased susceptibility to depression. However, the underlying mechanisms and importance of BBB damage in depression remains largely unknown. This review highlights how BBB disruption regulates the depression process and the possible molecular mechanisms involved in development of depression-induced BBB dysfunction. Moreover, insight on promising therapeutic targets for treatment of depression with associated BBB dysfunctions are also discussed.

Periorbital Nociception in a Progressive Multiple Sclerosis Mouse Model Is Dependent on TRPA1 Channel Activation

Headaches are frequently described in progressive multiple sclerosis (PMS) patients, but their mechanism remains unknown. Transient receptor potential ankyrin 1 (TRPA1) was involved in neuropathic nociception in a model of PMS induced by experimental autoimmune encephalomyelitis (PMS-EAE), and TRPA1 activation causes periorbital and facial nociception. Thus, our purpose was to observe the development of periorbital mechanical allodynia (PMA) in a PMS-EAE model and evaluate the role of TRPA1 in periorbital nociception. Female PMS-EAE mice elicited PMA from day 7 to 14 days after induction. The antimigraine agents olcegepant and sumatriptan were able to reduce PMA. The PMA was diminished by the TRPA1 antagonists HC-030031, A-967079, metamizole and propyphenazone and was absent in TRPA1-deficient mice. Enhanced levels of TRPA1 endogenous agonists and NADPH oxidase activity were detected in the trigeminal ganglion of PMS-EAE mice. The administration of the anti-oxidants apocynin (an NADPH oxidase inhibitor) or alpha-lipoic acid (a sequestrant of reactive oxygen species), resulted in PMA reduction. These results suggest that generation of TRPA1 endogenous agonists in the PMS-EAE mouse model may sensitise TRPA1 in trigeminal nociceptors to elicit PMA. Thus, this ion channel could be a potential therapeutic target for the treatment of headache in PMS patients.

Age-related changes in cerebrovascular health and their effects on neural function and cognition: A comprehensive review

The process of aging includes changes in cellular biology that affect local interactions between cells and their environments and eventually propagate to systemic levels. In the brain, where neurons critically depend on an efficient and dynamic supply of oxygen and glucose, age-related changes in the complex interaction between the brain parenchyma and the cerebrovasculature have effects on health and functioning that negatively impact cognition and play a role in pathology. Thus, cerebrovascular health is considered one of the main mechanisms by which a healthy lifestyle, such as habitual cardiorespiratory exercise and a healthful diet, could lead to improved cognitive outcomes with aging. This review aims at detailing how the physiology of the cerebral vascular system changes with age and how these changes lead to differential trajectories of cognitive maintenance or decline. This provides a framework for generating specific mechanistic hypotheses about the efficacy of proposed interventions and lifestyle covariates that contribute to enhanced cognitive well-being. Finally, we discuss the methodological implications of age-related changes in the cerebral vasculature for human cognitive neuroscience research and propose directions for future experiments aimed at investigating age-related changes in the relationship between physiology and cognitive mechanisms.

Exercise rapidly alters proteomes in mice following spinal cord demyelination

Exercise affords broad benefits for people with multiple sclerosis (PwMS) including less fatigue, depression, and improved cognition. In animal models of multiple sclerosis (MS), exercise has been shown to improve remyelination, decrease blood-brain barrier permeability and reduce leukocyte infiltration. Despite these benefits many PwMS refrain from engaging in physical activity. This barrier to participation in exercise may be overcome by uncovering and describing the mechanisms by which exercise promotes beneficial changes in the central nervous system (CNS). Here, we show that acute bouts of exercise in mice profoundly alters the proteome in demyelinating lesions. Following lysolecithin induced demyelination of the ventral spinal cord, mice were given immediate access to a running wheel for 4 days. Lesioned spinal cords and peripheral blood serum were then subjected to tandem mass tag labeling shotgun proteomics workflow to identify alteration in protein levels. We identified 86 significantly upregulated and 85 downregulated proteins in the lesioned spinal cord as well as 14 significantly upregulated and 11 downregulated proteins in the serum following acute exercise. Altered pathways following exercise in demyelinated mice include oxidative stress response, metabolism and transmission across chemical synapses. Similar acute bout of exercise in naïve mice also changed several proteins in the serum and spinal cord, including those for metabolism and anti-oxidant responses. Improving our understanding of the mechanisms and duration of activity required to influence the injured CNS should motivate PwMS and other conditions to embrace exercise as part of their therapy to manage CNS disability.