Relationship between the clinical scoring and demyelination in central nervous system with total antioxidant capacity of plasma during experimental autoimmune encephalomyelitis development in mice

The Neuroprotective Effect of Erythropoietin on the Optic Nerve and Spinal Cord in Rats with Experimental Autoimmune Encephalomyelitis through the Activation of the Extracellular Signal-Regulated Kinase 1/2 Signaling Pathway

Experimental autoimmune encephalomyelitis is a demyelinating disease that causes paralysis in laboratory rats. This condition lacks treatment that reverses damage to the myelin sheaths of neuronal cells. Therefore, in this study, treatment with EPO as a neuroprotective effect was established to evaluate the ERK 1/2 signaling pathway and its participation in the EAE model. EPO was administered in 5000 U/Kg Sprague Dawley rats. U0126 was used as an inhibitor of the ERK 1/2 pathway to demonstrate the possible activation of this pathway in the model. Spinal cord and optic nerve tissues were evaluated using staining techniques such as H&E and the Luxol Fast Blue myelin-specific technique, as well as immunohistochemistry of the ERK 1/2 protein. The EPO-treated groups showed a decrease in cellular sampling in the spinal cord tissues but mainly in the optic nerve, as well as an increase in the expression of the ERK 1/2 protein in both tissues. The findings of this study suggest that EPO treatment reduces cellular death in EAE-induced rats by regulating the ERK pathway.

The expression of anti-aging protein Klotho is increased during neural differentiation of bone marrow-derived mesenchymal stem cells

Klotho, as an antiaging protein, is involved in the maintenance and differentiation of neuronal or glial cells and, therefore, has been noticed as a potential therapeutic target for neurodegenerative disorders. Expression of Klotho has been examined in different cells and organs, however, our information about the developmental pattern of this protein during differentiation of mesenchymal stem cells (MSCs) into neuron-like cells is limited. In this study, we conducted neural differentiation of mouse bone marrow-derived-MSCs and monitored the expression of Klotho together with selected neuron-specific genes at messenger RNA (mRNA) on days 7 and 14 of differentiation using quantitative real-time PCR. In addition, Klotho status at protein level was evaluated by immunocytochemistry. The results showed a significant change in the morphology of MSCs towards neuron-like cells. These changes were observed with progressive growth and formation of cell connections towards the formation of a chain of neuron-like cells which occurred in the second week of differentiation. Morphological changes were associated with a significant increase in the expression of neuron-specific genes like pax-6, neuN and, neurofilaments (NfL). Likewise, there was an increased expression of Klotho mRNA, and accumulation of Klotho protein in neuronal cell bodies, during the cellular differentiation of MSCs. These findings provided new evidence that neuronal differentiation from the MSCs is associated with increased expression of Klotho. These data may provide insight into the importance of Klotho protein in stem cell differentiation and regeneration in response to cell death in the central nervous system.

Glutathione: pharmacological aspects and implications for clinical use

Glutathione is a tripeptide found in many tissues which plays a pivotal role in critical physiological processes such as maintenance of redox balance, reduction of oxidative stress by enhancement of metabolic detoxification of both xenobiotic and endogenous compounds, and regulation of immune system function. Glutathione depletion is associated with many chronic degenerative diseases and loss of function with aging and altered glutathione metabolism has been implicated in central nervous system diseases, frailty and sarcopenia, infected state, chronic liver diseases, metabolic diseases, pulmonary and cardiovascular diseases. Therefore, the glutathione status may be an important biomarker and treatment target in various chronic, age-related diseases. Here we describe the main pharmacological aspects of glutathione, focusing on its synthesis and role in several vital functions including antioxidant defense, detoxification of xenobiotics and modulation of immune function and fibrogenesis and the clinical implications of its depletion and we discuss the different strategies for increasing glutathione cellular levels either by providing specific precursors and cofactors or directly administering the tripeptide.

Immunoregulatory Effects of Tolerogenic Probiotics in Multiple Sclerosis

Gut microbiota has essential roles in the prevention and progression of multiple sclerosis (MS). The association between the gut microbiota and the central nervous system (CNS) or immune system response of MS patients has been documented in many studies. The composition of the gut microbiota could lead to sensitization or resistance against promotion and development of MS disease. Probiotics are the major part of gut microflorapopulation and could be substituted with tolerogenic probiotics that protect the CNS against autoimmune responses. Tolerogenic probiotics with anti-inflammatory and immuno-modulatory properties have effects on intestinal flora and can reestablish regulatory mucosal and systemic immune responses. Probiotics are able to prevent and restore excessive activation of inflammatory responses, especially autoreactive T cells and inflammatory cytokines. Tolerogenic probiotics, through induction of regulatory T cells and increase of anti-inflammatory cytokines, play a crucial role in controlling inflammation and maintaining tolerance and hemostasis. Therefore, probiotics can be considered as a preventive or therapeutic tool in MS. In the present review, we focus on the immunoregulatory effects of tolerogenic probiotics on the severity of disease, as well as Th1, Th2, and Treg populations in different experimental and human studies of MS.

Susceptibility to erastin-induced ferroptosis decreases during maturation in a human oligodendrocyte cell line

Ferroptosis, a form of iron‐dependent cell death caused by lipid peroxidation, has been implicated in neurological and other disorders. However, the mechanism of ferroptosis in oligodendrocytes is unclear. We tested the susceptibility of MO3.13 cells, an oligodendrocyte line, to ferroptosis after erastin treatment. Immature MO3.13 cells were more susceptible to erastin‐induced ferroptosis than chemically differentiated mature MO3.13 cells. Increased expression of solute carrier family 7 member 11 (SLC7A11), which encodes a cystine/glutamate transporter, and greater glutathione concentrations were observed in mature compared with immature MO3.13 cells, linking glutathione to the resistance of mature MO3.13 cells to erastin‐induced ferroptosis. These findings highlight the usefulness of immature MO3.13 cells in studies of ferroptosis and investigations into neuropathologies that involve oligodendrocytes.

An Apparent Correlation Between Central Nervous System and Kidney's Erythropoietin and TNF Alpha Expression at Peak Experimental Autoimmune Encephalomyelitis Disease

Experimental autoimmune encephalomyelitis (EAE) is an inflammatory demyelination disease associated with inflammatory reactions and attenuation of antioxidant capacity. Several lines of evidence show that organs such as the liver and kidneys can share their antioxidant activity to protect the central nervous system (CNS) against neurodegenerative diseases. The aim of this study was to examine the possible interplay of the kidneys and CNS in pathogenesis of EAE. For this purpose, EAE model was induced in C57BL/6 mice, and expression of erythropoietin (EPO), TNF-α, and NFκB-1 was determined in the kidney and CNS at early and peak stages of the disease. Besides, changes in serum level of EPO and total antioxidant capacity (TAC) were measured by different clinical scores. Real-time PCR (qPCR) results showed a substantial increase in TNF-α and NFκB-1 expression in mice at EAE peak stage compared to sham (control). There was a positive correlation between kidney-EPO and CNS-inflammatory factor expression in EAE-induced mice. In general, EPO expression was relatively higher in the kidneys compared to CNS tissue in sham group. There was a significant upregulation in expression of EPO in the brain, spinal cord, and kidneys particularly at peak stage. Accordingly, changes in serum TAC were consistent with serum EPO concentration. This data may suggest that there is an EPO-mediated cross-talk between the kidney and CNS during EAE pathogenesis.

Glutathione and glutathione derivatives in immunotherapy

Reduced glutathione (GSH) is the most prevalent non-protein thiol in animal cells. Its de novo and salvage synthesis serves to maintain a reduced cellular environment, which is important for several cellular functions. Altered intracellular GSH levels are observed in a wide range of pathologies, including several viral infections, as well as in aging, all of which are also characterized by an unbalanced Th1/Th2 immune response. A central role in influencing the immune response has been ascribed to GSH. Specifically, GSH depletion in antigen-presenting cells (APCs) correlates with altered antigen processing and reduced secretion of Th1 cytokines. Conversely, an increase in intracellular GSH content stimulates IL-12 and/or IL-27, which in turn induces differentiation of naive CD4+ T cells to Th1 cells. In addition, GSH has been shown to inhibit the replication/survival of several pathogens, i.e. viruses and bacteria. Hence, molecules able to increase GSH levels have been proposed as new tools to more effectively hinder different pathogens by acting as both immunomodulators and antimicrobials. Herein, the new role of GSH and its derivatives as immunotherapeutics will be discussed.

Comparative Neuroregenerative Effects of C-Phycocyanin and IFN-Beta in a Model of Multiple Sclerosis in Mice

Multiple Sclerosis (MS) therapies approved so far are unable to effectively reverse the chronic phase of the disease or improve the remyelination process. Here our aim is to evaluate the effects of C-Phycocyanin (C-Pc), a biliprotein from Spirulina platensis with anti-oxidant, anti-inflammatory and cytoprotective properties, in a chronic model of experimental autoimmune encephalomyelitis (EAE) in mice. C-Pc (2, 4 or 8 mg/kg i.p.) or IFN-beta (2000 IU, s.c.) was administered daily once a day or every other day, respectively, starting at disease onset, which differ among EAE mice between 11 and 15 days postinduction. Histological and immunohistochemistry (anti-Mac-3, anti-CD3 and anti-APP) assessments were performed in spinal cord in the postinduction time. Global gene expression in the brain was analyzed with the Illumina Mouse WG-6_V2 BeadChip microarray and the expression of particular genes, assessed by qPCR using the Fast SYBR Green RT-PCR Master Mix. Oxidative stress parameters (malondialdehyde, peroxidation potential, CAT/SOD ratio and GSH) were determined spectrophoto-metrically. Results showed that C-Pc ameliorates the clinical deterioration of animals, an effect that expresses the reduction of the inflammatory infiltrates invading the spinal cord tissue, the axonal preservation and the down-regulation of IL-17 expression in brain tissue and serum. C-Pc and IFN-beta improved the redox status in mice subjected to EAE, while microarray analysis showed that both treatments shared a common subset of differentially expressed genes, although they also differentially modulated another subset of genes. Specifically, C-Pc mainly modulated the expression of genes related to remyelination, gliogenesis and axon-glia processes. Taken together, our results indicate that C-Pc has significant therapeutic effects against EAE, mediated by the dynamic regulation of multiple biological processes.

Influence of Hemodialysis on Lipid Peroxidation, Enzymatic and Non-Enzymatic Antioxidant Capacity in Chronic Renal Failure Patients

BACKGROUND

Free radical induced damages are thought to be involved in chronic kidney disease (CKD), especially in patients who are on hemodialysis (HD) for prolonged periods. Hemodialysis can influence multiple biochemical factors, several of which are useful, although the rest can be harmful and increase the severity of disease.

OBJECTIVES

The purpose of this study was to evaluate the effect of the HD membrane polysulfone on oxidative stress markers, by measuring the level of lipid peroxidation and total antioxidant activity (TAC), in the blood of HD patients.

PATIENTS AND METHODS

This study was carried out on 31 HD patients and 31 healthy persons, matched for age and sex, as control group. Blood samples were drawn before and after HD from arteriovenous fistulas, and once from the controls. Superoxide dismutase (SOD), catalase (CAT) and thiobarbituric acid-reactive substance (TBARS) in blood hemolyzate, Glutathione peroxidase (GpX) of whole blood and TAC of plasma were measured, respectively. Then, we investigated the association between TAC of plasma, measured by ferric reducing antioxidant power (FRAP), and lipid peroxidation level with its related parameters, in HD patients.

RESULTS

The SOD, GpX and CAT were decreased after HD (P < 0.05). Also, FRAP was shown to decrease after HD (P < 0.05). However, erythrocyte TBARS levels (μmol/gr of Hb) were increased after HD, in comparison with controls, and before HD (P < 0.05). There was a significant negative correlation between TBARS and antioxidant indices, such as SOD (r = -0.67, P = 0.001), GpX (r = -0.76, P = 0.001), CAT (r = -0.63, P = 0.001) and FRAP (r = -0.84, P = 0.001). The FRAP was significantly and directly correlated with uric acid (r = +0.62, P = 0.001), SOD (r = +0.72, P = 0.001), GpX (r = +0.87, P = 0.001) and CAT (r = +0.84, P = 0.001).

CONCLUSIONS

The results of our study proposed that there is a loss or inactivation of antioxidant factors, coupled with increased lipid peroxidation during the procedure of HD, possibly through the dialyzer membrane, with probable consequences on the severity of illness.

Inflammatory demyelination induces glia alterations and ganglion cell loss in the retina of an experimental autoimmune encephalomyelitis model

Background

Multiple sclerosis (MS) is often accompanied by optic nerve inflammation. And some patients experience permanent vision loss. We examined if the grade of optic nerve infiltration and demyelination affects the severity of clinical signs in an experimental autoimmune encephalomyelitis (EAE) model. The loss of retinal ganglion cells (RGC) and alterations in glia activity were also investigated.

Methods

C57BL/6 mice were immunized with peptide MOG_35-55 in complete Freund’s adjuvant (CFA) and controls received PBS in CFA. Then 23 days post immunization eyes were prepared for flatmounts and stained with Nissl to evaluated neuronal density. Clinical EAE symptoms as well as cell infiltration and demyelination in the optic nerve were examined. Retinal sections were stained with hematoxylin and eosin and silver stain. Immunohistochemistry was used to label RGCs (Brn-3a), apoptotic cells (caspase 3), macroglia (glial fibrillary acidic protein (GFAP)), microglia (Iba1), macrophages (F 4/80) and interleukin-6 (IL-6) secretion.

Results

EAE symptoms started at day 8 and peaked at day 15. Cell infiltrations (P = 0.0047) and demyelination (P = 0.0018) of EAE nerves correlated with the clinical score (r > 0.8). EAE led to a significant loss of RGCs (P< 0.0001). Significantly more caspase 3⁺ cells were noted in these animals (P = 0.0222). They showed an increased expression of GFAP (P< 0.0002) and a higher number of microglial cells (P< 0.0001). Also more macrophages and IL-6 secretion were observed in EAE mice.

Conclusions

MOG immunization leads to optic neuritis and RGC loss. EAE severity is related to the severity of optic nerve inflammation and demyelination. EAE not only affects activation of apoptotic signals, but also causes a glial response in the retina.

Astragaloside IV attenuates experimental autoimmune encephalomyelitis of mice by counteracting oxidative stress at multiple levels

Multiple sclerosis (MS) is a chronic autoimmune neuroinflammatory disease found mostly in young adults in the western world. Oxidative stress induced neuronal apoptosis plays an important role in the pathogenesis of MS. In current study, astragaloside IV (ASI), a natural saponin molecule isolated from Astragalus membranceus, given at 20 mg/kg daily attenuated the severity of experimental autoimmune encephalomyelitis (EAE) in mice significantly. Further studies disclosed that ASI treatment inhibited the increase of ROS and pro-inflammatory cytokine levels, down-regulation of SOD and GSH-Px activities, and elevation of iNOS, p53 and phosphorylated tau in central nervous system (CNS) as well as the leakage of BBB of EAE mice. Meanwhile, the decreased ratio of Bcl-2/Bax was reversed by ASI. Moreover, ASI regulated T-cell differentiation and infiltration into CNS. In neuroblast SH-SY5Y cells, ASI dose-dependently reduced cellular ROS level and phosphorylation of tau in response to hydrogen peroxide challenge by modulation of Bcl-2/Bax ratio. ASI also inhibited activation of microglia both in vivo and in vitro. iNOS up-regulation induced by IFNγ stimulation was abolished by ASI dose-dependently in BV-2 cells. In summary, ASI prevented the severity of EAE progression possibly by counterbalancing oxidative stress and its effects via reduction of cellular ROS level, enhancement of antioxidant defense system, increase of anti-apoptotic and anti-inflammatory pathways, as well as modulation of T-cell differentiation and infiltration into CNS. The study suggested ASI may be effective for clinical therapy/prevention of MS.

Global and 3D spatial assessment of neuroinflammation in rodent models of Multiple Sclerosis

Multiple Sclerosis (MS) is a progressive autoimmune inflammatory and demyelinating disease of the central nervous system (CNS). T cells play a key role in the progression of neuroinflammation in MS and also in the experimental autoimmune encephalomyelitis (EAE) animal models for the disease. A technology for quantitative and 3 dimensional (3D) spatial assessment of inflammation in this and other CNS inflammatory conditions is much needed. Here we present a procedure for 3D spatial assessment and global quantification of the development of neuroinflammation based on Optical Projection Tomography (OPT). Applying this approach to the analysis of rodent models of MS, we provide global quantitative data of the major inflammatory component as a function of the clinical course. Our data demonstrates a strong correlation between the development and progression of neuroinflammation and clinical disease in several mouse and a rat model of MS refining the information regarding the spatial dynamics of the inflammatory component in EAE. This method provides a powerful tool to investigate the effect of environmental and genetic forces and for assessing the therapeutic effects of drug therapy in animal models of MS and other neuroinflammatory/neurodegenerative disorders.

Human bone marrow-derived mesenchymal stem cells induce Th2-polarized immune response and promote endogenous repair in animal models of multiple sclerosis

Cell-based therapies are attractive approaches to promote myelin repair. Recent studies demonstrated a reduction in disease burden in mice with experimental allergic encephalomyelitis (EAE) treated with mouse mesenchymal stem cells (MSCs). Here, we demonstrated human bone marrow-derived MSCs (BM-hMSCs) promote functional recovery in both chronic and relapsing-remitting models of mouse EAE, traced their migration into the injured CNS and assayed their ability to modulate disease progression and the host immune response. Injected BM-hMSCs accumulated in the CNS, reduced the extent of damage and increased oligodendrocyte lineage cells in lesion areas. The increase in oligodendrocytes in lesions may reflect BM-hMSC-induced changes in neural fate determination, since neurospheres from treated animals gave rise to more oligodendrocytes and less astrocytes than nontreated neurospheres. Host immune responses were also influenced by BM-hMSCs. Inflammatory T-cells including interferon gamma producing Th1 cells and IL-17 producing Th17 inflammatory cells and their associated cytokines were reduced along with concomitant increases in IL-4 producing Th2 cells and anti-inflammatory cytokines. Together, these data suggest that the BM-hMSCs represent a viable option for therapeutic approaches.

Neuroprotective mesenchymal stem cells are endowed with a potent antioxidant effect in vivo

Experimental autoimmune encephalomyelitis (EAE), an animal model for human multiple sclerosis, is characterized by demyelination, inflammation and neurodegeneration of CNS in which free radicals play a role. Recently, the efficacy of murine mesenchimal stem cells (MSCs) as treatment of EAE induced in mice by the encephalitogenic peptide MOG(35-55) was demonstrated. The present study analyzed some markers of oxidative stress, inflammation/degeneration and apoptosis such as metallothioneins (MTs), antioxidant enzymes (superoxide dismutase, catalase and glutathione-S-transferase), poly(ADP-ribose) polymerase-1 and p53 during EAE progression and following MSC treatment. Expression of the three brain MT isoforms increased significantly in EAE mice compared with healthy controls, but while expression of MT-1 and MT-3 increased along EAE course, MT-2 was up-regulated at the onset, but returned to levels similar to those of controls in chronic phase. The changes in the transcription and activity of the antioxidant enzymes and in expression of poly(ADP-ribose) polymerase-1 and p53 showed the same kinetics observed for MT-1 and MT-3 during EAE. Interestingly, i.v. administration of MSCs reduced the EAE-induced increases in levels/activities of all these proteins. These results support an antioxidant and neuroprotective activity for MSCs that was also confirmed in vitro on neuroblastoma cells exposed to an oxidative insult.

Glutathione dysregulation and the etiology and progression of human diseases

Glutathione (GSH) plays an important role in a multitude of cellular processes, including cell differentiation, proliferation, and apoptosis, and as a result, disturbances in GSH homeostasis are implicated in the etiology and/or progression of a number of human diseases, including cancer, diseases of aging, cystic fibrosis, and cardiovascular, inflammatory, immune, metabolic, and neurodegenerative diseases. Owing to the pleiotropic effects of GSH on cell functions, it has been quite difficult to define the role of GSH in the onset and/or the expression of human diseases, although significant progress is being made. GSH levels, turnover rates, and/or oxidation state can be compromised by inherited or acquired defects in the enzymes, transporters, signaling molecules, or transcription factors that are involved in its homeostasis, or from exposure to reactive chemicals or metabolic intermediates. GSH deficiency or a decrease in the GSH/glutathione disulfide ratio manifests itself largely through an increased susceptibility to oxidative stress, and the resulting damage is thought to be involved in diseases, such as cancer, Parkinson's disease, and Alzheimer's disease. In addition, imbalances in GSH levels affect immune system function, and are thought to play a role in the aging process. Just as low intracellular GSH levels decrease cellular antioxidant capacity, elevated GSH levels generally increase antioxidant capacity and resistance to oxidative stress, and this is observed in many cancer cells. The higher GSH levels in some tumor cells are also typically associated with higher levels of GSH-related enzymes and transporters. Although neither the mechanism nor the implications of these changes are well defined, the high GSH content makes cancer cells chemoresistant, which is a major factor that limits drug treatment. The present report highlights and integrates the growing connections between imbalances in GSH homeostasis and a multitude of human diseases.

The acute and chronic phases of chronic relapsing experimental autoimmune encephalomyelitis (CR EAE) are ameliorated by the peroxynitrite decomposition catalyst, 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrinatoiron (III) chloride, (FeTPPS)

There is increasing evidence that the oxidative radical, peroxynitrite (ONOO(-)), is involved in the pathogenesis of inflammatory diseases including multiple sclerosis and the animal counterpart, experimental autoimmune encephalomyelitis (EAE). Compounds that impede the actions of ONOO(-) have proved useful in the control of EAE. In particular, catalytic isomerisation of ONOO(-) to inactive nitrate, through the use of metalloporphyrins, curtails the cellular response to inflammatory stimuli and halts the progression of neuroinflammation during EAE. The present study examined the pharmacological effects of the metalloporphyrin and ONOO(-) decomposition catalyst 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrinatoiron(III)chloride (FeTPPS) on the acute and relapse phases of chronic relapsing (CR) EAE. Administration of FeTPPS to CR EAE-inoculated Biozzi mice commenced either therapeutically and immediately prior to the emergence of acute or relapse symptoms, or prophylactically, from the onset of remission of acute neurological signs. Drug therapy reduced acute and relapse symptoms but, and in contrast to the former phase, was of limited benefit in preventing histological changes during the latter stage of disease. In contrast, prophylactic FeTPPS was effective in limiting CNS pathology and neurological deficits. The findings confirm the inhibitory effects of FeTPPS on acute stage EAE. Moreover, the study extends previous observations by verifying compound efficacy on relapsing disease. Use of metalloporphyrins, such as FeTPPS, again highlights the important role played by ONOO(-) in the development of inflammatory diseases such as EAE.

Evaluating epigenetic landmarks in the brain of multiple sclerosis patients: a contribution to the current debate on disease pathogenesis

The evidence suggesting a role of epigenetics in the definition of complex trait diseases is rapidly increasing. The gender prevalence of multiple sclerosis, the low level concordance in homozygous twins and the linkage to several genetic loci, suggest an epigenetic component to the definition of this demyelinating disorder. While the immune etio-pathogenetic mechanism of disease progression has been well characterized, still relatively little is known about the initial events contributing to onset and progression of the demyelinating lesion. This article addresses the challenging question of whether loss of the mechanisms of epigenetic regulation of gene expression in the myelinating cells may contribute to the pathogenesis of multiple sclerosis, by affecting the repair process and by modulating the levels of enzymes involved in neo-epitope formation. The role of altered post-translational modifications of nucleosomal histones and DNA methylation in white matter oligodendroglial cells are presented in terms of pathogenetic concepts and the relevance to therapeutic intervention is then discussed.