Cerebrospinal fluid and plasma oxidative stress biomarkers in different clinical phenotypes of neuroinflammatory acute attacks. Conceptual accession: from fundamental to clinic

Chelation Therapy Associated with Antioxidant Supplementation Can Decrease Oxidative Stress and Inflammation in Multiple Sclerosis: Preliminary Results

An imbalance of oxy-inflammation status has been involved in axonal damage and demyelination in multiple sclerosis (MS). The aim of this study was to investigate the efficacy of an antioxidant treatment (calcium disodium ethylenediaminetetracetic acid-EDTA) chelation therapy associated with a micronutrient complex in MS patients. A total of 20 MS patients and 20 healthy subjects, enrolled as a control group (CTR), were recruited. We measured the plasma ROS production and total antioxidant capacity (TAC) by a direct assessment using Electron Paramagnetic Resonance; activities of the antioxidant system (thiols' redox status and enzymes); and the urinary presence of biomarkers of oxidative stress by immunoenzymatic assays. We also evaluated the levels of inflammation by plasmatic cytokines (TNFα, IL-1β, and IL-6) and assessed the sICAM levels, as well as the nitric oxide (NO) catabolism and transthyretin (TTR) concentration. Comparing CTR and MS, in the latter ROS production, oxidative damage, inflammatory biomarkers, and NO metabolite concentrations results were significantly higher, while TAC was significantly lower. Treatment in MS induced significant (p < 0.05) down-regulating of pro-inflammatory sICAM1, TNF-α, IL6, as well as biomarkers of lipid peroxidation and DNA damage production. The protective effect exhibited may occur by decreasing ROS production and increasing antioxidant capacity, turning into a more reduced thiols' status.

A Scoping Review on Body Fluid Biomarkers for Prognosis and Disease Activity in Patients with Multiple Sclerosis

Multiple sclerosis (MS) is a complex demyelinating disease of the central nervous system, presenting with different clinical forms, including clinically isolated syndrome (CIS), which is a first clinical episode suggestive of demyelination. Several molecules have been proposed as prognostic biomarkers in MS. We aimed to perform a scoping review of the potential use of prognostic biomarkers in MS clinical practice. We searched MEDLINE up to 25 November 2021 for review articles assessing body fluid biomarkers for prognostic purposes, including any type of biomarkers, cell types and tissues. Original articles were obtained to confirm and detail the data reported by the review authors. We evaluated the reliability of the biomarkers based on the sample size used by various studies. Fifty-two review articles were included. We identified 110 molecules proposed as prognostic biomarkers. Only six studies had an adequate sample size to explore the risk of conversion from CIS to MS. These confirm the role of oligoclonal bands, immunoglobulin free light chain and chitinase CHI3L1 in CSF and of serum vitamin D in the prediction of conversion from CIS to clinically definite MS. Other prognostic markers are not yet explored in adequately powered samples. Serum and CSF levels of neurofilaments represent a promising biomarker.

Circulatory antioxidant and oxidative stress markers are in correlation with demographics but not cognitive functions in multiple sclerosis patients

BACKGROUND

Multiple sclerosis (MS) is the most common non-traumatic cause of disability in younger adults. MS can be presented with a wide range of symptoms such as cognitive impairment (CI). Oxidative stress (OXS) is a major basis of the pathogenesis of MS. There is a positive correlation between OXS factors and the progression of the disease in MS patients. There are limited studies regarding the role of OXS in MS-related CI. In this study, as an exploratory analysis, we assess the role of endogenous antioxidants and OXS factors in cognitive function, the severity of disability due to MS, and demographic findings in a sample of MS patients.

METHODS

Adult (>18 years old) patients with a definite diagnosis of MS based on 2017 revised MacDonald criteria were included in this study. The neurophysiological assessment was conducted, using the validated Persian version of minimal assessment of cognitive function in multiple sclerosis (MACFIMS) battery, which is composed of seven different tests. Based on the structure of the battery, CI was defined as a failure in at least two different components of the MACFIMS battery. The patients were separated into two groups of CI and non-CI. Examined antioxidant factors included catalase Activity (CAT), Glutathione Peroxidase 1 (GPX1), Glutathione Peroxidase 2 (GPX2), Reduced Glutathione (GSH), Superoxide Dismutase (SOD), and serum total antioxidant capacity (TAC). Malondialdehyde (MDA) was also measured as an OXS marker.

RESULTS

71 patients were involved in this study. The type of MS was relapsing-remitting MS (RRMS) in 80.28% of the participants. Disease duration (P<0.01), type of MS (p<0.01), and EDSS score (p<0.01) were different between CI and non-CI groups, but there were not any significant differences in CAT (p = 0.80), GPX1 (p = 0.71), GPX2 (p = 0.41), GSH (p = 0.96), TAC (p = 0.13), SOD (p = 0.37), and MDA (p = 0.82). A significant difference between RRMS and progressive MS (PMS) patients in the levels of GPX1 (p = 0.01), GPX2 (p = 0.01), and SOD (p = 0.01) was observed. Also, we found higher circulatory levels of CAT (p = 0.02) and TAC (p<0.01) in male MS patients. We found significant correlations between aging and CAT (R = 0.28; p = 0.01), GPX1 (R = 0.36; p<0.01), GPX2 (R = 0.34; p<0.01), and SOD (R = 0.40; p<0.01). EDSS, the duration of the disease, relapse rate, and the number of impaired cognitive tasks were not correlated with any of investigated OXS or antioxidant factors (p>0.05). In terms of a detailed investigation of associations between MACFIMS battery components and levels of OXS and antioxidant factors, there were no significant relations in this regard (p>0.05). Based on the logistic regression multivariate analysis, only disease duration (p = 0.03) and GPX1 (p = 0.01) were independently associated with CI in MS patients in our sample.

CONCLUSION

The circulatory levels of GPX1, GPX2, and SOD are significantly different between RRMS and PMS patients. Neither endogenous antioxidants nor MDA, as an OXS biomarker, are associated with the cognitive function or level of physical disability in MS patients. Limitations of this study suggest a need for future studies in a larger sample of MS patients.

Decreased Cerebrospinal Fluid Antioxidative Capacity Is Related to Disease Severity and Progression in Early Multiple Sclerosis

Background: Oxidative stress-induced neuronal damage in multiple sclerosis (MS) results from an imbalance between toxic free radicals and counteracting antioxidants, i.e., antioxidative capacity (AOC). The relation of AOC to outcome measures in MS still remains inconclusive. We aimed to compare AOC in cerebrospinal fluid (CSF) and serum between early MS and controls and assess its correlation with clinical/radiological measures. Methods: We determined AOC (ability of CSF and serum of patients to inhibit 2,2′-azobis(2-amidinopropane) dihydrochloride-induced oxidation of dihydrorhodamine) in clinically isolated syndrome (CIS)/early relapsing-remitting MS (RRMS) (n = 55/11) and non-inflammatory neurological controls (n = 67). MS patients underwent clinical follow-up (median, 4.5; IQR, 5.2 years) and brain MRI at 3 T (baseline/follow-up n = 47/34; median time interval, 3.5; IQR, 2.1 years) to determine subclinical disease activity. Results: CSF AOC was differently regulated among CIS, RRMS and controls (p = 0.031) and lower in RRMS vs. CIS (p = 0.020). Lower CSF AOC correlated with physical disability (r = −0.365, p = 0.004) and risk for future relapses (exp(β) = 0.929, p = 0.033). No correlations with MRI metrics were found. Conclusion: Decreased CSF AOC was associated with increased disability and clinical disease activity in MS. While our finding cannot prove causation, they should prompt further investigations into the role of AOC in the evolution of MS.

Redox Imbalance in CD4+ T Cells of Relapsing-Remitting Multiple Sclerosis Patients

As a prevalent autoimmune disease of the central nervous system in young adults, multiple sclerosis (MS) is mediated by T cells, particularly CD4+ subsets. Given the evidence that the perturbation in reactive oxygen species (ROS) production has a pivotal role in the onset and progression of MS, its regulation through the antioxidant molecules is too important. Here, we investigated the level of the redox system components in lymphocytes and CD4+ T cells of MS patients. The study was performed on relapsing-remitting MS (RRMS) patients (n = 29) and age- and sex-matched healthy controls (n = 15). Peripheral blood mononuclear cells (PBMCs) were cultured and stimulated by anti-CD3/CD28. The level of ROS, anion superoxide (O₂ ^-), and L-𝛾-glutamyl-Lcysteinylglycine (GSH) was measured by flow cytometry in lymphocytes/CD4+ T cells. The gene expression level of gp91phox, catalase, superoxide dismutase 1/2 (SOD), and nuclear factor-E2-related factor (Nrf2) was also measured by real-time PCR. We found that lymphocytes/CD4+ T cells of RRMS patients at the relapse phase significantly produced higher levels of ROS and O₂ ^- compared to patients at the remission phase (P value < 0.001) and healthy controls (P value < 0.001 and P value < 0.05, respectively). Interestingly, the gene expression level of gp91phox, known as the catalytic subunit of the NADPH oxidase, significantly increased in MS patients at the relapse phase (P value < 0.05). Furthermore, the catalase expression augmented in patients at the acute phase (P value < 0.05), while an increased expression of SOD1 and Nrf2 was found in RRMS patients at relapse and remission phases (P value < 0.05). The increased production of ROS in CD4+ T cells of RRMS patients highlights the importance of amplifying antioxidant components as an efficient approach to ameliorate disease activity in MS patients.

Monitoring the Redox Status in Multiple Sclerosis

Worldwide, over 2.2 million people suffer from multiple sclerosis (MS), a multifactorial demyelinating disease of the central nervous system. MS is characterized by a wide range of motor, autonomic, and psychobehavioral symptoms, including depression, anxiety, and dementia. The blood, cerebrospinal fluid, and postmortem brain samples of MS patients provide evidence on the disturbance of reduction-oxidation (redox) homeostasis, such as the alterations of oxidative and antioxidative enzyme activities and the presence of degradation products. This review article discusses the components of redox homeostasis, including reactive chemical species, oxidative enzymes, antioxidative enzymes, and degradation products. The reactive chemical species cover frequently discussed reactive oxygen/nitrogen species, infrequently featured reactive chemicals such as sulfur, carbonyl, halogen, selenium, and nucleophilic species that potentially act as reductive, as well as pro-oxidative stressors. The antioxidative enzyme systems cover the nuclear factor erythroid-2-related factor 2 (NRF2)-Kelch-like ECH-associated protein 1 (KEAP1) signaling pathway. The NRF2 and other transcriptional factors potentially become a biomarker sensitive to the initial phase of oxidative stress. Altered components of the redox homeostasis in MS were discussed in search of a diagnostic, prognostic, predictive, and/or therapeutic biomarker. Finally, monitoring the battery of reactive chemical species, oxidative enzymes, antioxidative enzymes, and degradation products helps to evaluate the redox status of MS patients to expedite the building of personalized treatment plans for the sake of a better quality of life.

Oxidative Stress Marker Aberrations in Multiple Sclerosis: A Meta-Analysis Study

Oxidative stress has been suggested to play a key role in multiple sclerosis (MS), but clinical data on oxidative stress markers in MS patients were inconsistent. This study sought to quantitatively summarize the data of oxidative stress markers in the blood and cerebrospinal fluid (CSF) of patients with MS in the literature. We conducted a systematic search of PubMed and Web of Science and included studies if they provided data on the concentrations of oxidative stress markers in the peripheral blood and CSF of MS patients and healthy control (HC) subjects. The systematic search resulted in the inclusion of 31 studies with 2,001 MS patients and 2,212 HC subjects for meta-analysis. Random-effects meta-analysis demonstrated that patients with MS had significantly increased concentrations of blood oxidative stress markers compared with HC subjects for malondialdehyde (MDA; Hedges' g, 2.252; 95% CI, 1.080 to 3.424; p < 0.001) and lipid hydroperoxide by tert-butyl hydroperoxide-initiated chemiluminescence (CL-LOOH; Hedges' g, 0.383; 95% CI, 0.065 to 0.702; p = 0.018). In contrast, concentrations of albumin (Hedges' g, −1.036; CI, −1.679 to −0.394; p = 0.002) were significantly decreased in MS patients when compared with those in HC subjects. However, the other analyzed blood oxidative stress markers did not show significant differences between cases and controls. Furthermore, this meta-analysis showed significant association between CSF MDA and MS (Hedges' g, 3.275; 95% CI, 0.859 to 5.691; p = 0.008). Taken together, our results revealed increased blood and CSF MDA and decreased blood albumin levels in patients with MS, strengthening the clinical evidence of increased oxidative stress in MS.

Oxidative stress-related biomarkers in multiple sclerosis: a review

AIM

To provide an up-to-date review of oxidative stress biomarkers in multiple sclerosis and thus identify candidate molecules with greatest promise as biomarkers of diagnosis, disease activity or prognosis.

METHOD

A semi-systematic literature search using PubMed and other databases.

RESULTS

Nitric oxide metabolites, superoxide dismutase, catalase, glutathione reductase, inducible nitric oxide synthase, protein carbonyl, 3-nitrotyrosine, isoprostanes, malondialdehyde and products of DNA oxidation have been identified across multiple studies as having promise as diagnostic, therapeutic or prognostic markers in MS.

CONCLUSION

Heterogeneity of study design, particularly patient selection, limits comparability across studies. Further cohort studies are needed, and we would recommend promising markers be incorporated into future clinical trials to prospectively validate their potential.

Oxidative Stress and Neurobiology of Demyelination

Despite a large amount of research which aims at defining the pathophysiology of human demyelination (i.e., multiple sclerosis), etiological bases of disease have been unknown so far. The point of intersection of all assumed etiological factors, which are mainly based upon immunological cascades, is neuroinflammation. The precise definition of the place and role of all pathogenetic factors in the occurrence and development of the disease is of crucial importance for understanding the clinical nature and for finding more effective therapeutic options. There are few studies whose results give more precise data about the role and the importance of other factors in neuroinflammation, besides immunological ones, with regard to clinical and paraclinical correlates of the disease. The review integrates results found in previously performed studies which have evaluated oxidative stress participation in early and late neuroinflammation. The largest number of studies indicates that the use of antioxidants affects the change of neuroinflammation course under experimental conditions, which is reflected in the reduction of the severity and the total reversibility in clinical presentation of the disease, the faster achieving of remission, and the delayed and slow course of neuroinflammation. Therapies based on the knowledge of redox biology targeting free radical generation hold great promise in modulation of the neuroinflammation and its clinical presentations.

The importance of nitric oxide and arginase in the pathogenesis of acute neuroinflammation: are those contra players with the same direction?

To investigate the concentrations of nitric oxide (NO) products (NOx) and arginase activity in acute neuroinflammation, we analyzed cerebrospinal fluid (CSF) and plasma of clinically isolated syndrome (CIS) and relapsing remitting multiple sclerosis (RRMS) patients, who were divided into groups on the basis of clinical and radiological disease activity. The NOx levels, in both, CSF and plasma, were increased in CIS (p = 0.0015, p = 0.0014, respectively) and RRMS group (p = 0.002, p = 0.0019, respectively), while arginase activity approached low levels, in CIS (p = 0.009, p = 0.02, respectively) and RRMS group (p = 0.018, p = 0.034, respectively) compared to controls. The NOx levels were higher in CSF and plasma of CIS than in RRMS group (p = 0.065, p = 0.037, respectively), inverse to arginase activity which was higher, in CSF and plasma, in RRMS than in CIS group (p = 0.031, p = 0.02, respectively). The CSF and plasma NOx values positively correlated with the clinical disease activity in CIS (r = 0.09, p = 0.81; r = 0.45, p = 0.023, respectively) and RRMS group (r = 0.311, p = 0.04; r = 0.512, p = 0.01, respectively). Also, CSF and plasma arginase activity showed negative correlation with clinical disease activity in CIS (r = 0.39, p = 0.03; r = 0.1, p = 0.65, respectively) and RRMS group (r = 0.43, p = 0.03; r = 0.62, p = 0.015, respectively). The CSF NOx levels showed positive correlation with volume of acute radiological lesions of CNS in CIS (r = 0.25, p = 0.045) and RRMS group (r = 0.31, p = 0.04), while arginase activity showed the negative correlations in CIS (r = 0.41; p = 0.035) and RRMS group (r = 0.52, p = 0.022). The results support NO and arginase involvement in the pathogenesis of acute neuroinflammation, which determination may be useful as surrogate markers for clinical and radiological disease activity.

Glutathione homeostasis disruption of erythrocytes, but not glutathione peroxidase activity change, is closely accompanied with neurological and radiological scoring of acute CNS inflammation

OBJECTIVES AND METHODS

The levels of glutathione (GSH) and glutathione peroxidase (GPx) activity were measured in the erythrocytes of 50 patients with clinically isolated syndrome of CNS (CIS) and 57 patients with relapsing remitting multiple sclerosis (RRMS).

RESULTS

A decrease in GSH content and GPx activity showed significance in both study groups compared to the control values (p = 0.0025 and 0.007 for GSH and p = 0.005 and 0.003 for GPx, in CIS and RRMS patients, respectively). The depletions were more pronounced in RRMS than in CIS patients (p = 0.009 for GSH and p = 0.031 for GPx). The results significantly verify the negative correlations between GSH values and clinical severity (r = -0.513, p = 0.004), radiological findings (r = -0.351, p = 0.008) and disease duration (r = -0.412, p = 0.0025) in CIS patients. The same correlations were observed in RRMS patients between GSH values and clinical severity (r = -0.498, p = 0.004) and patients' radiological features (r = -0.454, p = 0.005). No correlations were observed between GSH values and other patient characteristics, or between GPx activity and all tested patient characteristics (p > 0.01).

CONCLUSIONS

The results indicate that GSH content and GPx activity both decreased below the normal range and were accompanied with neuroinflammation, but although both might have great importance in neuroinflammation development, the data presented here confirm that only GSH might serve as a marker which is closely correlated with neurological and radiological scoring of acute CNS inflammation.