Is Geo-Environmental Exposure a Risk Factor for Multiple Sclerosis? A Population-Based Cross-Sectional Study in South-Western Sardinia

Scutellarin Attenuates Pro-Inflammatory Foam Cell Formation and Facilitates M2 Polarization in Microglia during Copper Homeostasis Imbalance via the MAPK Signaling Pathway

BACKGROUND

Clinical and experimental evidence indicates that copper has the ability to promote the progressive development of demyelinating diseases such as multiple sclerosis. Microglia-mediated neuroinflammation is believed to play a crucial role in this process. Scutellarin, a flavonoid compound, has anti-inflammatory, antioxidative, and neuroprotective effects.

AIM

We investigated the effect of scutellarin on copper-induced inflammatory foam cell formation in microglia.

METHODS

We exposed BV2 murine microglial cells to copper, then collected the conditioned medium and co-cultured it with MO3.13 human glial cells to mimic myelin damage in vitro. The Cell Counting kit-8 assay, quantitative (polymerase chain reaction) PCR, enzyme-linked immunosorbent assay, Luxol fast blue staining, and western blotting were used to detect the cell phenotype. To investigate whether exposure of BV2 cells to copper can cause neurotoxicity and indirect damage to myelin cells, we determined whether BV2 cells promote inflammation through foam cell formation by oil red O staining and detection of malondialdehyde (MDA) content. Finally, we treated cells with scutellarin to investigate its therapeutic effects.

RESULTS

Exposure to copper activated the pro-inflammatory phenotype of microglia, as assessed by measuring the transcription of M1/M2-related biomarkers. In addition, increased copper intake by microglia promoted intracellular lipid accumulation and oxidation, facilitating foam cell formation. Rescue experiments showed that copper chelator ammonium tetrathiomolybdate (ATTM) and the lipid oxidation inhibitor ferrostatin-1 (Fer-1) significantly inhibited copper-induced inflammation, reduced intracellular lipid accumulation and MDA levels, and decreased foam cell formation. Moreover, copper-induced phosphorylation of p38 mitogen-activated protein kinase (MAPK) in microglia led to a shift towards the M1 phenotype and foam cell transformation, which were effectively inhibited by ATTM, Fer-1, and the p38 MAPK inhibitor SB203580. Lastly, after treatment with scutellarin, copper-induced foam microglia exhibited inhibited p38 MAPK phosphorylation, increased production of neurotrophic factors, decreased expression of inflammatory mediators, reduced lipid accumulation, and induced polarization towards the M2 phenotype.

CONCLUSIONS

Here, we demonstrated that copper can induce microglia to damage myelinating cells, with the key mechanism involving the phosphorylation of p38 MAPK. Scutellarin partially reversed the positive effects of copper on promoting microglial M1 polarization, lipid deposition, and lipid oxidation by mediating the p38 MAPK signaling pathway. Taken together, these results suggest that scutellarin may be a promising drug for the treatment of demyelinating diseases such as multiple sclerosis.

The interplay of gut microbiota and heavy metals in multiple sclerosis patients

Multiple Sclerosis (MS) is a chronic inflammatory disease characterized by central nervous system (CNS). In this study, the concentration of heavy metals was measured in stool samples of MS patients by Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS) method and compared with healthy people. Also, another goal of this study is to investigate the alteration of the gut microbiome of MS patients by metagenomics technique based on the 16S rRNA gene sequencing. The IL-10 ELISA assay showed no significant differences between the serum level of the IL-10 in the patients and the control group (p = 0.510). Heavy metal measurement by ICP-MS showed significantly higher levels of arsenic (As, Mean = 32.77 μg/kg), nickel (Ni, Mean = 7.154 μg/kg), manganese (Mn, Mean = 3723 μg/kg), and zinc (Zn, Mean = 5508 μg/kg) in the stool samples of the MS group compared to the control group, while concentrations of iron (Fe, Mean = 9585 μg/kg), lead (Pb, Mean = 18.54 μg/kg), titanium (Ti, Mean = 69.69 μg/kg), and tin (Sn, Mean = 13.92 μg/kg) were significantly lower. The result of gut microbiome analysis showed an increase in the abundance of the Verrumicrobiaceae, Lachnospiraceae and Ruminococcaceae families was considerably increased in MS patients compared to the control group (p < 0.05). This study reports that high levels of heavy metals such as Ars, Ni, Mn, and Zn, deficiency of Fe, Pb, Ti, and Sn, and alteration of the gut microbiome are involved in the pathogenesis of MS. The novelty of this study lies in its multi-faceted approach to understanding MS by integrating the measurement of heavy metals in stool samples with the analysis of gut microbiome alterations, thereby providing comprehensive insights into heavy metals, the gut microbiome, and potential therapeutic avenues. This study suggests several potential applications and practical implications based on its findings regarding heavy metals, gut microbiome alterations, and IL-10 levels in MS. First, the identification of elevated levels of specific heavy metals and deficiencies in others may lead to targeted screening and monitoring, informing preventive strategies for MS patients. Additionally, the observed gut microbiome changes could facilitate the development of microbiome-based therapies, such as probiotics or dietary interventions, aimed at restoring microbial balance. Finally, exploring the interplay between heavy metals, gut microbiome, and immune response may guide the creation of novel therapeutic interventions, ultimately enhancing treatment efficacy and providing new avenues for managing MS, thereby alleviating the burden of this chronic condition.

Geospatial analysis of environmental atmospheric risk factors in neurodegenerative diseases: a systematic review update

Following up the previously published systematic review on the same topic and realizing that new studies and evidence had emerged on the matter, we conducted an update on the same research terms. With the objective of updating the information relating environmental risk factors on neurodegenerative diseases and the geographic approaches used to address them, we searched PubMed, Web of Science and Scopus for all scientific studies considering the following three domains: neurodegenerative disease, environmental atmospheric factor and geographical analysis, using the same keywords as in the previously published systematic review. From February 2020 to February 2023, 35 papers were included versus 34 in the previous period, with dementia (including Alzheimer's disease) being the most focused disease (60.0%) in this update, opposed to multiple sclerosis on the last review (55.9%). Also, environmental pollutants such as PM2.5 and NO2 have gained prominence, being represented in 65.7% and 42.9% of the new studies, opposed to 9.8% and 12.2% in the previous review, compared to environmental factors such as sun exposure (5.7% in the update vs 15.9% in the original). The mostly used geographic approach remained the patient's residence (82.9% in the update vs 21.2% in the original and 62.3% in total), and remote sensing was used in 45.7% of the new studies versus 19.7% in the original review, with 42.0% of studies using it globally, being the second most common approach, usually to compute the environmental variable. This review has been registered in PROSPERO with the number CRD42020196188.

Use of geographical information systems in multiple sclerosis research: A systematic scoping review

INTRODUCTION

Geographical information system (GIS) and spatial analysis have an emerging role in the understanding and management of health-related outcomes. However, there is a knowledge gap about the extent to which GIS has supported multiple Sclerosis (MS) research. Therefore, this review aimed to explore the types of GIS applications and the complexity of their visualisation in MS research.

METHODS

A systematic scoping review was conducted based on York's five-stage framework. PubMed, Scopus and Web of Science were searched for relevant studies published between 2000 and 2020 using a comprehensive search strategy based on the main concepts related to GIS and MS. Grounded, inductive analysis was conducted to organize studies into meaningful application areas. Further, we developed a tool to assess the visualisation complexity of the selected papers.

RESULTS

Of 3,723 identified unique citations, 42 papers met our inclusion criteria for the final review. One or more of the following types of GIS applications were reported by these studies: (a) thematic mapping (37 papers); (b) spatial cluster detection (16 papers); (c) risk factors detection (16 papers); and (d) health access and planning (two papers). In the majority of studies (88%), the score of visualisation complexity was relatively low: three or less from the range of zero to six.

CONCLUSIONS

Although the number of studies using GIS techniques has dramatically increased in the last decade, the use of GIS in the areas of MS access and planning is still under-researched. Additionally, the capacity of GIS in visualising complex nature of MS care system is not yet fully investigated.

Associations of essential and toxic metals/metalloids in whole blood with both disease severity and mortality in patients with COVID-19

The variations and dynamics of essential and toxic metal(loid)s in patients with COVID-19 may associate with the progression and fatal outcome of the disease, which still remains to investigate. In the present study, a retrospective analysis was performed in a cohort of 306 confirmed COVID-19 patients admitted to Tongji hospital (Wuhan, China) from February 10 to March 15, 2020. Whole blood levels of essential and/or toxic metal(loid)s were analyzed, including magnesium, calcium, chromium, manganese, iron, copper, zinc, arsenic, cadmium, mercury, thallium, and lead according to the disease severity and outcome. Compared to the non-severe COVID-19 patients, severe cases showed significant higher levels of whole blood calcium, chromium, and copper, but lower levels of magnesium, manganese, iron, zinc, arsenic, thallium, and lead. These differences were further found consistently across the clinical course since the disease onset by longitudinal analysis. Among the severe patients, chromium and cadmium were higher in the deceased group compared to the recovered group, while arsenic was lower. Whole blood iron, age, and sex were determined to be independent factors associated with the disease severity, while chromium, cadmium, and the comorbidity of cardiovascular disease were determined to be independent factors associated with the mortality. These results suggest that variations of whole blood metal(loid)s may be associated with the severe illness and fatal outcome of COVID-19, which could be persistently monitored and would be helpful in the evaluation of the dynamic changes in patients with COVID-19.

Geospatial Analysis of Environmental Atmospheric Risk Factors in Neurodegenerative Diseases: A Systematic Review

Despite the vast evidence on the environmental influence in neurodegenerative diseases, those considering a geospatial approach are scarce. We conducted a systematic review to identify studies concerning environmental atmospheric risk factors for neurodegenerative diseases that have used geospatial analysis/tools. PubMed, Web of Science, and Scopus were searched for all scientific studies that included a neurodegenerative disease, an environmental atmospheric factor, and a geographical analysis. Of the 34 included papers, approximately 60% were related to multiple sclerosis (MS), hence being the most studied neurodegenerative disease in the context of this study. Sun exposure (n = 13) followed by the most common exhaustion gases (n = 10 for nitrogen dioxide (NO₂) and n = 5 for carbon monoxide (CO)) were the most studied atmospheric factors. Only one study used a geospatial interpolation model, although 13 studies used remote sensing data to compute atmospheric factors. In 20% of papers, we found an inverse correlation between sun exposure and multiple sclerosis. No consensus was reached in the analysis of nitrogen dioxide and Parkinson’s disease, but it was related to dementia and amyotrophic lateral sclerosis. This systematic review (number CRD42020196188 in PROSPERO’s database) provides an insight into the available evidence regarding the geospatial influence of environmental factors on neurodegenerative diseases.

Relevance of Essential Trace Elements in Nutrition and Drinking Water for Human Health and Autoimmune Disease Risk

Trace elements produce double-edged effects on the lives of animals and particularly of humans. On one hand, these elements represent potentially toxic agents; on the other hand, they are essentially needed to support growth and development and confer protection against disease. Certain trace elements and metals are particularly involved in humoral and cellular immune responses, playing the roles of cofactors for essential enzymes and antioxidant molecules. The amount taken up and the accumulation in human tissues decisively control whether the exerted effects are toxic or beneficial. For these reasons, there is an urgent need to re-consider, harmonize and update current legislative regulations regarding the concentrations of trace elements in food and in drinking water. This review aims to provide information on the interrelation of certain trace elements with risk of autoimmune disease, with a particular focus on type 1 diabetes and multiple sclerosis. In addition, an overview of the current regulations and regulatory gaps is provided in order to highlight the importance of this issue for everyday nutrition and human health.

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.

Total intake of different minerals and the risk of multiple sclerosis

OBJECTIVE

To investigate the association between mineral intake (potassium, magnesium, calcium, phosphorus, iron, zinc, manganese, copper) and multiple sclerosis (MS) risk.

METHODS

In a prospective cohort study, we assessed dietary and supplemental mineral intake by a validated food frequency questionnaire administered every 4 years to 80,920 nurses in the Nurses' Health Study (1984-2002) and 94,511 in the Nurses' Health Study II (1991-2007). There were 479 new MS cases during follow-up. We estimated hazard ratios and 95% confidence intervals for the association of energy-adjusted mineral intake with MS risk using Cox regression, adjusting for age, residence latitude at age 15, ancestry, body mass index at age 18, supplemental vitamin D, smoking, and total energy intake.

RESULTS

We did not find any association between the minerals and MS risk, either for baseline or cumulative intake during follow-up. The associations were null comparing women with highest to those with lowest intakes in quintiles or deciles and there was no significant trend for higher intakes (p _trend across baseline quintiles: potassium 0.35, magnesium 0.13, calcium 0.22, phosphorus 0.97, iron 0.85, zinc 0.67, manganese 0.48, copper 0.59).

CONCLUSIONS

Our findings suggest that mineral intake is not an important determinant of MS risk.

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

Multiple sclerosis (MS), a chronic inflammatory disease of the central nervous system is common amongst young adults, leading to major personal and socioeconomic burdens. However, it is still considered complex and challenging to understand and treat, in spite of the efforts made to explain its etiopathology. Despite the discovery of many genetic and environmental factors that might be related to its etiology, no clear answer was found about the causes of the illness and neither about the detailed mechanism of these environmental triggers that make individuals susceptible to MS. In this review, we will attempt to explore the major contributors to MS autoimmunity including genetic, epigenetic and ecological factors with a particular focus on toxins, chemicals or drugs that may trigger, modify or prevent MS disease.

Lower Serum Zinc Levels in Patients with Multiple Sclerosis Compared to Healthy Controls

OBJECTIVE

Diminished blood levels of zinc have been reported to be associated with T-cell-mediated autoimmunity, which has been implicated in multiple sclerosis (MS). We aimed to compare the distribution of serum zinc status in MS patients with that in healthy controls (HCs) and to investigate a potential correlation with clinical state, through analysis of serum zinc concentration in MS patients suffering from different disease subtypes.

METHODS

Serum zinc concentrations of 133 patients with relapsing (RMS) and 18 patients with the progressive form of MS (PMS), according to the McDonald criteria of 2010, were measured. Clinical status was quantified using the Expanded Disability Status Scale (EDSS). Zinc concentrations were also determined in the sera of 50 HCs, matched for age and sex at a group level.

RESULTS

MS patients showed significantly lower zinc concentrations (mean (SD)) than HCs (12.5 (2.1) µmol/L vs. 14.6 (2.3) µmol/L, p < 0.001). In contrast, we did not find any difference between RMS (12.4 (2.0) µmol/L) and PMS (13.0 (3.0) µmol/L) cases (p = 0.8). Patients receiving disease-modifying treatment showed lower mean (SD) serum zinc levels than untreated cases (12.3 (1.9) µmol/L vs. 13.5 (3.2) µmol/L, p < 0.03). Zinc levels were not related to disease duration, EDSS, annual relapse rate, or the median number of relapses.

CONCLUSIONS

The data suggest that a diagnosis of MS is related to lower serum zinc concentrations than in HCs, and concentrations were lower still under disease-modifying therapy. However, zinc levels did not predict disease subtypes or disability status.

Zinc Status and Autoimmunity: A Systematic Review and Meta-Analysis

Zinc is an essential trace element for living organisms and their biological processes. Zinc plays a key role in more than 300 enzymes and it is involved in cell communication, proliferation, differentiation and survival. Zinc plays also a role in regulating the immune system with implications in pathologies where zinc deficiency and inflammation are observed. In order to examine the experimental evidence reported in the literature regarding zinc levels in the body of patients with autoimmune disorders compared to control individuals, a systematic review and meta-analysis were performed. From 26,095 articles identified by literature search, only 179 of them were considered potentially relevant for our study and then examined. Of the 179 articles, only 62 satisfied the inclusion criteria. Particularly for Fixed Model, Zn concentration in both serum (mean effect = -1.19; confidence interval: -1.26 to -1.11) and plasma (mean effect = -3.97; confidence interval: -4.08 to -3.87) samples of autoimmune disease patients was significantly lower than in controls. The data presented in our work, although very heterogeneous in the manner of collecting and investigating samples, have proved to be extremely consistent in witnessing a deficiency of zinc in serum and plasma of patients compared to controls.

Dietary habits; concentration of copper, zinc, and Cu-to-Zn ratio in serum and ability status of patients with relapsing-remitting multiple sclerosis

OBJECTIVE

Dietary habits and adequate intake of antioxidants in the diet-for example, copper (Cu) and zinc (Zn)-may be an environmental factor in the occurrence of multiple sclerosis (MS). The aim of this study was to estimate the influence of dietary habits on the concentration of Cu, Zn in the serum, and the effect of Cu-to-Zn ratio on the ability status of patients with relapsing-remitting MS.

METHODS

This was an observational case-control study that included 101 individuals with MS and 68 healthy individuals (controls). Food frequency questionnaires were used to collect dietary data. Serum concentrations of Cu and Zn were determined by the electrothermal and flame atomic absorption spectrometry method, respectively. The ratio of Cu to Zn was calculated and compared with the Expanded Disability Status Scale of patients.

RESULTS

The concentration of Zn was significantly lower in the serum of individuals with MS (0.776 ± 0.195 mg/L) than in the control group (0.992 ± 0.315 mg/L). The ratio of Cu to Zn was higher in the examined patients (1.347 ± 0.806) than in the healthy volunteers (1.012 ± 0.458). Lower ability status (P < 0.05) was revealed in patients with an abnormal ratio of Cu to Zn, particularly, in cerebellar function, pyramidal tracts, and emotional conditions. Selected dietary habits have a significant influence on Cu and Zn concentration in the serum of patients with MS.

CONCLUSIONS

Lower serum concentrations of Zn and higher ratio of Cu to Zn in patients with MS can suggest a relationship between MS and oxidative stress. Products that are a source of Zn should be included in the diet, which can improve the clinical condition of people with MS.