The Beneficial and Debilitating Effects of Environmental and Microbial Toxins, Drugs, Organic Solvents and Heavy Metals on the Onset and Progression of Multiple Sclerosis

The impact of social and environmental factors on triggering multiple sclerosis onset, before and during the COVID-19 pandemic: a retrospective study from Iran

BACKGROUND

Multiple sclerosis (MS) is a chronic, inflammatory, and demyelinating disease of the central nervous system. The first presentation's possible triggers are still controversial among scientists. The objective of this study is to investigate and compare the potential social, environmental, and physical factors that may have contributed to the onset of MS before and during the Coronavirus Disease 2019 (COVID-19) pandemic.

METHODS

A questionnaire was designed in the MS research center of Sina Hospital and also distributed as an online Google Form on social media among Iranian MS patients. Demographic information, MS disease-related data, and possible patients reported MS triggers were recorded. They were containing stressful life events, COVID-19 and other infections, COVID-19 and other vaccines, pregnancy or labor, head trauma, surgery, and weight loss. Patients were divided into two groups regarding the time of MS diagnosis (before and during the COVID-19 pandemic).

RESULTS

Of 920 participants, 670 (72.8%) were female, and the mean age ± SD was 35.63 ± 8.1. The majority of patients (69.2%) had non-progressive forms of MS, and only 7.6% needed assistance for ambulation. 69% of participants were diagnosed with MS before the onset of the COVID-19 pandemic. There was a statistically significant difference between the most common first MS symptom before and after the beginning of the pandemic (visual type (n: 317 (49.9%)) before and sensory type (n: 170 (59.6%)) after the COVID-19 pandemic). A stressful life event was the most common patient-reported trigger of MS first presentation in both groups. (56.1% before and 54% after the COVID-19 pandemic). Comparing two groups, economic problems (AOR: 1.81; 95% ACI: 1.23-2.65) and job losses (AOR: 2.89; 95% ACI: 1.37-6.08) were significantly more common triggers for the initial presentation of MS after the pandemic, while the stress of occupational or educational exams (AOR: 0.52; 95% ACI: 0.34-0.79) was more prevalent before the pandemic.

CONCLUSION

Patients believe that stressful life events are closely linked to triggering their first MS symptoms. Since the beginning of the COVID-19 pandemic, economic problems and job losses have increased; however, occupational or educational exams stress decreased. Caring for social stress by societies may affect MS development or delay MS onset.

Review of evidence linking exposure to environmental stressors and associated alterations in the dynamics of immunosenescence (ISC) with the global increase in multiple sclerosis (MS)

Historical survey confirms that, over the latter part of the 20th century, autoimmune-based diseases, including multiple sclerosis (MS), have shown a worldwide increase in incidence and prevalence. Analytical population studies have established that the exponential rise in MS is not solely due to improvements in diagnosis and healthcare but relates to an increase in autoimmune risk factors. Harmful environmental exposures, including non-communicable social determinants of health, anthropogens and indigenous or transmissible microbes, constitute a group of causal determinants that have been closely linked with the global rise in MS cases. Exposure to environmental stressors has profound effects on the adaptive arm of the immune system and, in particular, the associated intrinsic process of immune ageing or immunosenescence (ISC). Stressor-related disturbances to the dynamics of ISC include immune cell-linked untimely or premature (p) alterations and an accelerated replicative (ar) change. A recognised immune-associated feature of MS is pISC and current evidence supports the presence of an arISC during the disease. Moreover, collated data illustrates the immune-associated alterations that characterise pISC and arISC are inducible by environmental stressors strongly implicated in causing duplicate changes in adaptive immune cells during MS. The close relationship between exposure to environmental risk factors and the induction of pISC and arISC during MS offers a valid mechanism through which pro-immunosenescent stressors may act and contribute to the recorded increase in the global rate and number of new cases of the disease. Confirmation of alterations to the dynamics of ISC during MS provides a rational and valuable therapeutic target for the use of senolytic drugs to either prevent accumulation and enhance ablation of less efficient untimely senescent adaptive immune cells or decelerate the dysregulated process of replicative proliferation. A range of senotherapeutics are available including kinase and transcriptase inhibitors, rapalogs, flavanols and genetically-engineered T cells and the use of selective treatments to control emerging and unspecified aspects of pISC and arISC are discussed.

Investigation of the Relationship Between Heavy Metals (Cadmium, Arsenic, and Lead) and Metallothionein in Multiple Sclerosis

BACKGROUND AND AIM

Multiple sclerosis (MS) is one of the most common neurological disorders. Metals are important for the maintenance and preservation of homeostasis and dysregulated metal homeostasis has an impact on neurodegeneration. Environmental factors are considered to contribute to MS risk and progression. Heavy metals such as arsenic (As), cadmium (Cd), and lead (Pb) are widely found in the environment and because of their toxic nature, they pose a great danger to human health. Metallothioneins (MTs) play important roles in metal homeostasis and detoxification of heavy metals.

OBJECTIVE

The aim of this study was to investigate the relationship between levels of heavy metals (As, Cd, and Pb) and MT levels in MS patients and also to assess the oxidative stress status of patients.

METHOD

Fifty subjects (20 healthy subjects and 30 MS patients) were included. Demographic characteristics of the patients, plasma MT levels, blood Cd, As, and Pb levels, as well as iron (Fe), copper (Cu), and zinc (Zn) levels, were determined. Malondialdehyde (MDA) levels were investigated as a marker of oxidative stress.

RESULTS

MT levels were slightly higher in the MS group (p > 0.05). As Cd and Pb levels were significantly higher in the control subjects. MDA levels were significantly higher in MS patients.

CONCLUSION

Our results support the relevance of MT and MDA levels in MS. Further clinical studies with larger cohorts will provide more insights into these factors.

Changes of Target Essential Trace Elements in Multiple Sclerosis: A Systematic Review and Meta-Analysis

(1) Background: Multiple sclerosis (MS) is a chronic, complex, and demyelinating disease closely associated with altered levels of trace elements. Although the first studies into the role of trace elements in MS were published in the 1970s, for five decades it has remained unknown whether trace elements can be part of this heterogeneous neurological disease. (2) Materials and methods: To drive toward at a potential solution, we conducted a systematic review and meta-analysis to elucidate whether there were differences in circulating levels of neurologically important essential trace elements (Zn, Fe, Co, Cu, Mn, and Se) between MS cases and controls. (3) Results: This study revealed significantly lower serum/plasma Zn and Fe levels and higher Cu levels in MS-affected individuals compared to controls. At the same time, no significant differences were found between the MS cases and controls regarding their serum/plasma levels of Co, Mn, or Se. Thus, the loss of Fe and Zn should be considered in supplementation/nutrition strategies for MS patients. On the other hand, since high serum Cu levels indicate a burden on the bloodstreams of MS patients, Cu should be excluded from mineral supplement strategies. Furthermore, all three trace elements (Fe, Zn, and Cu) should be considered from an etiological point of view, and, most importantly, their levels in the bloodstreams of MS patients should be monitored. (4) Conclusions: This study highlights the way for personalized and targeted strategies in the management of MS.

Unraveling the Epigenetic Landscape: Insights into Parkinson's Disease, Amyotrophic Lateral Sclerosis, and Multiple Sclerosis

Parkinson's disease (PD), multiple sclerosis (MS), and amyotrophic lateral sclerosis (ALS) are examples of neurodegenerative movement disorders (NMDs), which are defined by a gradual loss of motor function that is frequently accompanied by cognitive decline. Although genetic abnormalities have long been acknowledged as significant factors, new research indicates that epigenetic alterations are crucial for the initiation and development of disease. This review delves into the complex interactions that exist between the pathophysiology of NMDs and epigenetic mechanisms such DNA methylation, histone modifications, and non-coding RNAs. Here, we examine how these epigenetic changes could affect protein aggregation, neuroinflammation, and gene expression patterns, thereby influencing the viability and functionality of neurons. Through the clarification of the epigenetic terrain underpinning neurodegenerative movement disorders, this review seeks to enhance comprehension of the underlying mechanisms of the illness and augment the creation of innovative therapeutic strategies.

Novel Strategy to Assess the Neurotoxicity of Organic Solvents Such as Glycol Ethers: Protocol for Combining In Vitro and In Silico Methods With Human-Controlled Exposure Experiments

BACKGROUND

Chemicals are not required to be tested systematically for their neurotoxic potency, although they may contribute to the development of several neurological diseases. The absence of systematic testing may be partially explained by the current Organisation for Economic Co-operation and Development (OECD) Test Guidelines, which rely on animal experiments that are expensive, laborious, and ethically debatable. Therefore, it is important to understand the risks to exposed workers and the general population exposed to domestic products. In this study, we propose a strategy to test the neurotoxicity of solvents using the commonly used glycol ethers as a case study.

OBJECTIVE

This study aims to provide a strategy that can be used by regulatory agencies and industries to rank solvents according to their neurotoxicity and demonstrate the use of toxicokinetic modeling to predict air concentrations of solvents that are below the no observed adverse effect concentrations (NOAECs) for human neurotoxicity determined in in vitro assays.

METHODS

The proposed strategy focuses on a complex 3D in vitro brain model (BrainSpheres) derived from human-induced pluripotent stem cells (hiPSCs). This model is accompanied by in vivo, in vitro, and in silico models for the blood-brain barrier (BBB) and in vitro models for liver metabolism. The data are integrated into a toxicokinetic model. Internal concentrations predicted using this toxicokinetic model are compared with the results from in vivo human-controlled exposure experiments for model validation. The toxicokinetic model is then used in reverse dosimetry to predict air concentrations, leading to brain concentrations lower than the NOAECs determined in the hiPSC-derived 3D brain model. These predictions will contribute to the protection of exposed workers and the general population with domestic exposures.

RESULTS

The Swiss Centre for Applied Human Toxicology funded the project, commencing in January 2021. The Human Ethics Committee approval was obtained on November 16, 2022. Zebrafish experiments and in vitro methods started in February 2021, whereas recruitment of human volunteers started in 2022 after the COVID-19 pandemic-related restrictions were lifted. We anticipate that we will be able to provide a neurotoxicity testing strategy by 2026 and predicted air concentrations for 6 commonly used propylene glycol ethers based on toxicokinetic models incorporating liver metabolism, BBB leakage parameters, and brain toxicity.

CONCLUSIONS

This study will be of great interest to regulatory agencies and chemical industries needing and seeking novel solutions to develop human chemical risk assessments. It will contribute to protecting human health from the deleterious effects of environmental chemicals.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/50300.

Potentially toxic elements in the brains of people with multiple sclerosis

Potentially toxic elements such as lead and aluminium have been proposed to play a role in the pathogenesis of multiple sclerosis (MS), since their neurotoxic mechanisms mimic many of the pathogenetic processes in MS. We therefore examined the distribution of several potentially toxic elements in the autopsied brains of people with and without MS, using two methods of elemental bio-imaging. Toxicants detected in the locus ceruleus were used as indicators of past exposures. Autometallography of paraffin sections from multiple brain regions of 21 MS patients and 109 controls detected inorganic mercury, silver, or bismuth in many locus ceruleus neurons of both groups, and in widespread blood vessels, oligodendrocytes, astrocytes, and neurons of four MS patients and one control. Laser ablation-inductively coupled plasma-mass spectrometry imaging of pons paraffin sections from all MS patients and 12 controls showed that combinations of iron, silver, lead, aluminium, mercury, nickel, and bismuth were present more often in the locus ceruleus of MS patients and were located predominantly in white matter tracts. Based on these results, we propose that metal toxicants in locus ceruleus neurons weaken the blood-brain barrier, enabling multiple interacting toxicants to pass through blood vessels and enter astrocytes and oligodendroglia, leading to demyelination.

The Role of Systems Biology in Deciphering Asthma Heterogeneity

Asthma is one of the most common and lifelong and chronic inflammatory diseases characterized by inflammation, bronchial hyperresponsiveness, and airway obstruction episodes. It is a heterogeneous disease of varying and overlapping phenotypes with many confounding factors playing a role in disease susceptibility and management. Such multifactorial disorders will benefit from using systems biology as a strategy to elucidate molecular insights from complex, quantitative, massive clinical, and biological data that will help to understand the underlying disease mechanism, early detection, and treatment planning. Systems biology is an approach that uses the comprehensive understanding of living systems through bioinformatics, mathematical, and computational techniques to model diverse high-throughput molecular, cellular, and the physiologic profiling of healthy and diseased populations to define biological processes. The use of systems biology has helped understand and enrich our knowledge of asthma heterogeneity and molecular basis; however, such methods have their limitations. The translational benefits of these studies are few, and it is recommended to reanalyze the different studies and omics in conjugation with one another which may help understand the reasons for this variation and help overcome the limitations of understanding the heterogeneity in asthma pathology. In this review, we aim to show the different factors that play a role in asthma heterogeneity and how systems biology may aid in understanding and deciphering the molecular basis of asthma.

Mold, Mycotoxins and a Dysregulated Immune System: A Combination of Concern?

Fungi represent one of the most diverse and abundant eukaryotes on earth. The interplay between mold exposure and the host immune system is still not fully elucidated. Literature research focusing on up-to-date publications is providing a heterogenous picture of evidence and opinions regarding the role of mold and mycotoxins in the development of immune diseases. While the induction of allergic immune responses by molds is generally acknowledged, other direct health effects like the toxic mold syndrome are controversially discussed. However, recent observations indicate a particular importance of mold/mycotoxin exposure in individuals with pre-existing dysregulation of the immune system, due to exacerbation of underlying pathophysiology including allergic and non-allergic chronic inflammatory diseases, autoimmune disorders, and even human immunodeficiency virus (HIV) disease progression. In this review, we focus on the impact of mycotoxins regarding their impact on disease progression in pre-existing immune dysregulation. This is complemented by experimental in vivo and in vitro findings to present cellular and molecular modes of action. Furthermore, we discuss hypothetical mechanisms of action, where evidence is missing since much remains to be discovered.

Increase in Autoantibodies-Abzymes with Peroxidase and Oxidoreductase Activities in Experimental Autoimmune Encephalomyelitis Mice during the Development of EAE Pathology

The exact mechanisms of multiple sclerosis (MS) development are still unknown, but the development of experimental autoimmune encephalomyelitis (EAE) in C57BL/6 mice is associated with the violation of bone marrow hematopoietic stem cells (HSCs) differentiation profiles associated with the production of harmful for human’s autoantibodies hydrolyzing myelin basic protein, myelin oligodendrocyte glycoprotein (MOG_35–55), and DNA. It was shown that IgGs from the sera of healthy humans and autoimmune patients oxidize many different compounds due to their H₂O₂-dependent peroxidase and oxidoreductase activity in the absence of H₂O₂. Here we first analyzed the change in the relative redox activities of IgGs antibodies from the blood of C57BL/6 mice over time at different stages of the EAE development. It was shown that the peroxidase activity of mice IgGs in the oxidation of ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) is on average 6.9-fold higher than the oxidoreductase activity. The peroxidase activity of IgGs increased during the spontaneous development of EAE during 40 days, 1.4-fold. After EAE development acceleration due to mice immunization with MOG_35–55 (5.3-fold), complexes of bovine DNA with methylated bovine serum albumin (DNA-metBSA; 3.5-fold), or with histones (2.6-fold), the activity was increased much faster. The increase in peroxidase activity after mice immunization with MOG_35–55 and DNA-metBSA up to 40 days of experiments was relatively gradual, while for DNA-histones complex was observed its sharp increase at the acute phase of EAE (14–20 days). All data show that IgGs’ redox activities can play an important role in the protection of mice from toxic compounds and oxidative stress.

Targeting Chemokines and Chemokine Receptors in Multiple Sclerosis and Experimental Autoimmune Encephalomyelitis

Multiple sclerosis (MS) is an immune-mediated and neurodegenerative disorder that results in inflammation and demyelination of the central nervous system (CNS). MS symptoms include walking difficulties, visual weakening, as well as learning and memory impairment, thus affecting the quality of the patient's life. Chemokines and chemokine receptors are expressed on the immune cells as well as the CNS resident cells. Several sets of chemokine receptors and their ligands tend to be pathogenic players in MS, including CCL2, CCL3, CCL4, CCL5, CCL7, CCL8, CCL11, CCL17, CCL19, CCL21, CCL22, CXCL1, CXCL8, CXCL9, CXCL10, CXCL11, and CXCL16. Furthermore, current modulatory drugs that are used in the treatment of MS and its animal model, the experimental autoimmune encephalomyelitis (EAE), affect the expression of several chemokine and chemokine receptors. In this review, we highlight the pathogenic roles of chemokines and their receptors as well as utilizing them as potential therapeutic targets through selective agents, such as specific antibodies and receptor blockers, or indirectly through MS or EAE immunomodulatory drugs.

Drugs for Multiple Sclerosis Activate Natural Killer Cells: Do They Protect Against COVID-19 Infection?

COVID-19 infection caused by the newly discovered coronavirus severe acute respiratory distress syndrome virus-19 (SARS-CoV-2) has become a pandemic issue across the globe. There are currently many investigations taking place to look for specific, safe and potent anti-viral agents. Upon transmission and entry into the human body, SARS-CoV-2 triggers multiple immune players to be involved in the fight against the viral infection. Amongst these immune cells are NK cells that possess robust antiviral activity, and which do not require prior sensitization. However, NK cell count and activity were found to be impaired in COVID-19 patients and hence, could become a potential therapeutic target for COVID-19. Several drugs, including glatiramer acetate (GA), vitamin D₃, dimethyl fumarate (DMF), monomethyl fumarate (MMF), natalizumab, ocrelizumab, and IFN-β, among others have been previously described to increase the biological activities of NK cells especially their cytolytic potential as reported by upregulation of CD107a, and the release of perforin and granzymes. In this review, we propose that such drugs could potentially restore NK cell activity allowing individuals to be more protective against COVID-19 infection and its complications.

Clinical and MRI characteristics of multiple sclerosis in patients of Middle Eastern and North African ancestry residing in Ontario, Canada

BACKGROUND

Multiple sclerosis (MS) incidence is rising in traditionally low-burden regions, including the Middle East and North Africa (MENA).

OBJECTIVES

Our objective was to evaluate disease characteristics in MS patients of MENA descent (MENA-MS).

METHODS

MENA-MS patients and age- and sex-matched MS patients of European descent (EUR-MS) were identified through the MS Clinic Registry of St. Michael's Hospital in Toronto, Canada. Disease activity and severity were evaluated by the annualized relapse rate (ARR), magnetic resonance imaging (MRI) activity, change in the Expanded Disability Status Scale (EDSS), progression index (PI), and MS Severity Score (MSSS).

RESULTS

All MS patients within the registry identified to be of MENA origin (n = 192), and age- and sex-matched EUR-MS patients were included. Mean age was 42.9 years, 67% female. A total of 25% and 24% of EUR-MS and MENA-MS had progressive disease, with similar mean disease durations (11.5 and 11.4 years, respectively). Clinical and radiological disease activity (ARR, proportion with new/enlarging MRI lesions) was similar. MENA-MS showed greater disability progression over time (EDSS change = 0.24 vs. 0.06, p = 0.01), a higher MSSS (3.12 vs. 2.67, p = 0.04), and higher PI (0.34 vs. 0.27, p = 0.07).

CONCLUSION

MENA-MS patients demonstrate higher disease severity compared to EUR-MS patients, despite having similar inflammatory measures of disease activity, with disability progression in the absence of relapses. These observations illustrate the importance of the intersections of environmental, socioeconomic, and genetic determinants in optimizing individualized MS care.

Rituximab Prevents the Development of Experimental Autoimmune Encephalomyelitis (EAE): Comparison with Prophylactic, Therapeutic or Combinational Regimens

Objective

To investigate, in detail, the effects of rituximab (RTX), an off-label drug for treating multiple sclerosis (MS) disease on preventing and/or ameliorating experimental autoimmune encephalomyelitis (EAE).

Methods

Using bioinformatics analysis of publicly available transcriptomics data, we determined the accumulation of B cells, plasma cells and T cells in different compartments of multiple sclerosis patients (MS) and healthy individual brains. Based on these observations and on the literature search, we dosed RTX in EAE mice either orally, or injected intraperitoneally (IP). The latter route was used either prophylactically (asymptomatic stage; upon the induction of the disease), or therapeutically (acute stage; upon the appearance of the first sign of the disease). Further, we used RTX as a preventive drug either as a single agent or in combination with other routes of administration.

Results

Because no complete recovery was observed when RTX was used prophylactically or therapeutically, we devised another protocol of injecting this drug before the onset of the disease and designated this regiment as prevention. We demonstrated that the 20 μg/mouse prevention completely reduced the EAE clinical score, impaired infiltration of T and B cells into the perivascular space of mice brains, along with inhibiting the inflammation and demyelination. However, the 5 and 10 μg/mouse doses although reduced all aspects of inflammation in these mice, their effects were not as potent as the 20 μg/mouse RTX dose. Finally, we combined the 5 μg/mouse prevention treatment with either the prophylactic or therapeutic regimen and observed a robust effect.

Conclusion

We observed that combinatorial regimens resulted in further reduction of inflammation, T and B cell extravasation into the brains of EAE mice and improved the re-myelination.

Incidence of multiple sclerosis in the province of Catania. A geo-epidemiological study

BACKGROUND

An increasing incidence of MS in the city of Catania was reported during 1975-2004, with a higher incidence along the south-eastern flank of the Mt.Etna. We evaluated the incidence of MS in the entire province of Catania during 2005-2015 and the spatial distribution of MS-cases using a cluster analysis.

METHODS

Patients were considered as incident MS-cases if they fulfilled the revised McDonald criteria for MS during 2005-2015 and were residents in the province of Catania at the time of disease onset. Cluster analysis was performed using both LISA and Kulldorff's spatial scan statistic. Residence address at disease onset was considered for each case. Communalities were assessed considering the centroid of their inhabited area.

RESULTS

A total of 973 MS-cases were identified. Mean annual incidence risk was 8.2/100,000 person-years (95%CI 7.7-8.7), significantly higher among women (10.5/100,000 versus 5.7/100,000). LISA identified a spatial aggregation of MS-cases in the eastern side of the province of Catania and Kulldorff's statistics confirmed the existence of a statistically significant spatial cluster in this area (SIR 1.23,95%CI 1.08-1.23, p-value 0.04).

CONCLUSIONS

Our study confirms a high incidence of MS in the province of Catania and the presence of a spatial cluster along the eastern side of the province. This area is considered the most exposed to volcanogenic ashes due to the prevailing westerly to north-westerly trade winds. Even if such distribution could be related with a greater exposure to volcanogenic metals, further studies are needed to explore possible alternative hypotheses.

Gliotoxin Aggravates Experimental Autoimmune Encephalomyelitis by Triggering Neuroinflammation

Gliotoxin (GTX) is the major and the most potent mycotoxin that is secreted by Aspergillus fumigatus, which is capable of injuring and killing microglial cells, astrocytes, and oligodendrocytes. During the last years, studies with patients and experimental models of multiple sclerosis (MS), which is an autoimmune disease of the central nervous system (CNS), suggested that fungal infections are among the possible initiators or aggravators of this pathology. The deleterious effect can occur through a direct interaction of the fungus with the CNS or by the toxin release from a non-neurological site. In the present work, we investigated the effect of GTX on experimental autoimmune encephalomyelitis (EAE) development. Female C57BL/6 mice were immunized with myelin oligodendrocyte glycoprotein and then intraperitoneally injected with three doses of GTX (1 mg/kg b.w., each) on days 4, 7, and 10. GTX aggravated clinical symptoms of the disease in a dose-dependent way and this outcome was concomitant with an increased neuroinflammation. CNS analyses revealed that GTX locally increased the relative expression of inflammatory genes and the cytokine production. Our results indicate that GTX administered in a non-neuronal site was able to increase neuroinflammation in EAE. Other mycotoxins could also be deleterious to many neurological diseases by similar mechanisms.