Increased carbonylation, protein aggregation and apoptosis in the spinal cord of mice with experimental autoimmune encephalomyelitis

Oxidative Stress Markers in Multiple Sclerosis

The pathogenesis of multiple sclerosis (MS) is not completely understood, but genetic factors, autoimmunity, inflammation, demyelination, and neurodegeneration seem to play a significant role. Data from analyses of central nervous system autopsy material from patients diagnosed with multiple sclerosis, as well as from studies in the main experimental model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE), suggest the possibility of a role of oxidative stress as well. In this narrative review, we summarize the main data from studies reported on oxidative stress markers in patients diagnosed with MS and in experimental models of MS (mainly EAE), and case-control association studies on the possible association of candidate genes related to oxidative stress with risk for MS. Most studies have shown an increase in markers of oxidative stress, a decrease in antioxidant substances, or both, with cerebrospinal fluid and serum/plasma malonyl-dialdehyde being the most reliable markers. This topic requires further prospective, multicenter studies with a long-term follow-up period involving a large number of patients with MS and controls.

Anti-inflammatory, antioxidant and anti-mitophagy effects of trans sodium crocetinate on experimental autoimmune encephalomyelitis in BALB/C57 mice

Multiple sclerosis (MS) is an autoimmune disorder characterized by the degeneration of myelin and inflammation in the central nervous system. Trans sodium crocetinate (TSC), a novel synthetic carotenoid compound, possesses antioxidant, anti-inflammatory and neuroprotective effects. This study aimed to evaluate the protective effects of TSC against the development of experimental autoimmune encephalomyelitis (EAE), a well-established model for MS. Female BALB/C57 mice were divided into different groups, including control, EAE, vehicle, TSC-treated (25, 50, and 100 mg/kg, administered via gavage) + EAE, methyl prednisone acetate + EAE, and TSC-treated (100 mg/kg, administered via gavage for 28 days) groups. EAE was induced using MOG35-55, complete Freund's adjuvant, and pertussis toxin. In the mice spinal cord tissues, the oxidative markers (GSH and MDA) were measured using spectrophotometry and histological evaluation was performed. Mitophagic pathway proteins (PINK1and PARKIN) and inflammatory factors (IL-1β and TNF-α) were evaluated by western blot. Following 21 days post-induction, EAE mice exhibited weight loss, and the paralysis scores increased on day 13 but recovered after TSC (100 mg/kg) administration on day 16. Furthermore, TSC (50 and 100 mg/kg) reversed the altered levels of MDA and GSH in the spinal cord tissue of EAE mice. TSC (100 mg/kg) also decreased microgliosis, demyelination, and the levels of inflammatory markers IL-1β and TNF-α. Notably, TSC (100 mg/kg) modulated the mitophagy pathway by reducing PINK1 and Parkin protein levels. These findings demonstrate that TSC protects spinal cord tissue against EAE-induced MS through anti-inflammatory, antioxidant, and anti-mitophagy mechanisms.

Ferroptosis induces detrimental effects in chronic EAE and its implications for progressive MS

Ferroptosis is a form of lipid peroxidation-mediated cell death and damage triggered by excess iron and insufficiency in the glutathione antioxidant pathway. Oxidative stress is thought to play a crucial role in progressive forms of multiple sclerosis (MS) in which iron deposition occurs. In this study we assessed if ferroptosis plays a role in a chronic form of experimental autoimmune encephalomyelitis (CH-EAE), a mouse model used to study MS. Changes were detected in the mRNA levels of several ferroptosis genes in CH-EAE but not in relapsing-remitting EAE. At the protein level, expression of iron importers is increased in the earlier stages of CH-EAE (onset and peak). While expression of hemoxygenase-1, which mobilizes iron from heme, likely from phagocytosed material, is increased in macrophages at the peak and progressive stages. Excess iron in cells is stored safely in ferritin, which increases with disease progression. Harmful, redox active iron is released from ferritin when shuttled to autophagosomes by 'nuclear receptor coactivator 4' (NCOA4). NCOA4 expression increases at the peak and progressive stages of CH-EAE and accompanied by increase in redox active ferrous iron. These changes occur in parallel with reduction in the antioxidant pathway (system xCT, glutathione peroxidase 4 and glutathione), and accompanied by increased lipid peroxidation. Mice treated with a ferroptosis inhibitor for 2 weeks starting at the peak of CH-EAE paralysis, show significant improvements in function and pathology. Autopsy samples of tissue sections of secondary progressive MS (SPMS) showed NCOA4 expression in macrophages and oligodendrocytes along the rim of mixed active/inactive lesions, where ferritin+ and iron containing cells are located. Cells expressing NCOA4 express less ferritin, suggesting ferritin degradation and release of redox active iron, as indicated by increased lipid peroxidation. These data suggest that ferroptosis is likely to contribute to pathogenesis in CH-EAE and SPMS.

Neurobehavioral, biochemical and histological assessment of the effects of resveratrol on cuprizone-induced demyelination in mice: role of autophagy modulation

Resveratrol is known to exhibit neuroprotective effects in many neurological disorders via autophagy modulation. However, controversial results have been reported about the therapeutic potential of resveratrol and the implication of autophagy in demyelinating diseases. This study aimed to evaluate the autophagic changes in cuprizone-intoxicated C57Bl/6 mice and explore the effect of autophagy activation by resveratrol on the demyelination and remyelination processes. Mice were fed with chow containing 0.2% cuprizone for 5 weeks, followed by a cuprizone-free diet for 2 weeks. Resveratrol (250 mg/kg/day) and/or chloroquine (an autophagy inhibitor; 10 mg/kg/day) were given for 5 weeks starting from the third week. At the end of the experiment, animals were tested on rotarod and then sacrificed for biochemical assessment, luxol fast blue (LFB) staining, and transmission electron microscopy (TEM) imaging of the corpus callosum. We observed that cuprizone-induced demyelination was associated with impaired degradation of autophagic cargo, induction of apoptosis, and manifest neurobehavioral disturbances. Oral treatment with resveratrol promoted motor coordination and improved remyelination with regular compacted myelin in most axons without a significant impact on myelin basic protein (MBP) mRNA expression. These effects are mediated, at least in part, via activating autophagic pathways that may involve SIRT1/FoxO1 activation. This study verified that resveratrol dampens cuprizone-induced demyelination, and partially enhances myelin repair through modulation of the autophagic flux, since interruption of the autophagic machinery by chloroquine reversed the therapeutic potential of resveratrol.

Biomacromolecular Profile in Human Primary Retinal Pigment Epithelial Cells-A Study of Oxidative Stress and Autophagy by Synchrotron-Based FTIR Microspectroscopy

Synchrotron radiation-based Fourier Transform Infrared (SR-FTIR) microspectroscopy is a non-destructive and chemically sensitive technique for the rapid detection of changes in the different components of the cell's biomacromolecular profile. Reactive oxygen species and oxidative stress may cause damage to the DNA, RNA, and proteins in the retinal pigment epithelium (RPE), which can further lead to age-related macular degeneration (AMD) and visual loss in the elderly. In this study, human primary RPEs (hRPEs) were used to study AMD pathogenesis by using an established in vitro cellular model of the disease. Autophagy-a mechanism of intracellular degradation, which is altered during AMD, was studied in the hRPEs by using the autophagy inducer rapamycin and treated with the autophagy inhibitor bafilomycin A1. In addition, oxidative stress was induced by the hydrogen peroxide (H₂O₂) treatment of hRPEs. By using SR-FTIR microspectroscopy and multivariate analyses, the changes in the phosphate groups of nucleic acids, Amide I and II of the proteins, the carbonyl groups, and the lipid status in the hRPEs showed a significantly different pattern under oxidative stress/autophagy induction and inhibition. This biomolecular fingerprint can be evaluated in future drug discovery studies affecting autophagy and oxidative stress in AMD.

Dysregulation of Iron Homeostasis in the Central Nervous System and the Role of Ferroptosis in Neurodegenerative Disorders

Significance: Iron accumulation occurs in the central nervous system (CNS) in a variety of neurological conditions as diverse as spinal cord injury, stroke, multiple sclerosis, Parkinson's disease, and others. Iron is a redox-active metal that gives rise to damaging free radicals if its intracellular levels are not controlled or if it is not properly sequestered within cells. The accumulation of iron occurs due to dysregulation of mechanisms that control cellular iron homeostasis. Recent Advances: The molecular mechanisms that regulate cellular iron homeostasis have been revealed in much detail in the past three decades, and new advances continue to be made. Understanding which aspects of iron homeostasis are dysregulated in different conditions will provide insights into the causes of iron accumulation and iron-mediated tissue damage. Recent advances in iron-dependent lipid peroxidation leading to cell death, called ferroptosis, has provided useful insights that are highly relevant for the lipid-rich environment of the CNS. Critical Issues: This review examines the mechanisms that control normal cellular iron homeostasis, the dysregulation of these mechanisms in neurological disorders, and more recent work on how iron can induce tissue damage via ferroptosis. Future Directions: Quick and reliable tests are needed to determine if and when ferroptosis contributes to the pathogenesis of neurological disorders. In addition, there is need to develop better druggable agents to scavenge lipid radicals and reduce CNS damage for neurological conditions for which there are currently few effective treatments. Antioxid. Redox Signal. 37, 150-170.

T-cell-specific Sel1L deletion exacerbates EAE by promoting Th1/Th17-cell differentiation

Multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE) are demyelinating neuroinflammatory diseases identified by the accumulation and aggregation of misfolded proteins in the brain. The Sel1L-Hrd1 complex comprising endoplasmic reticulum associated degradation (ERAD) is an ER-protein quality control system (ERQC) in the cell. Unfortunately, the contribution of ERAD to the development of these diseases has not been well explored. In this study, we used mice with a conditional deletion (KO) of Sel1L in T cells to dissect the role of ERAD on T cells and its contribution to the development of EAE. The results showed that Sel1L KO mice developed more severe EAE than the control wild type (WT) mice. Although, no obvious effects on peripheral T cells in steady state, more CD44-CD25+ double-negative stage 3 (DN3) cells were detected in the thymus. Moreover, Sel1L deficiency promoted the differentiation of Th1 and Th17 cells and upregulated the proliferation and apoptosis of CD4 T cells in vitro. Regarding the mechanism analyzed by RNA sequencing, 437 downregulated genes and 271 upregulated genes were detected in Sel1L deletion CD4 T cells, which covered the activation, proliferation, differentiation and apoptosis of these T cells. Thus, this study declared that the dysfunction of Sel1L in ERAD in T cells exacerbated the severity of EAE and indicated the important role of ERQC in maintaining immune homeostasis in the central nervous system.

Recent Approaches to Determine Static and Dynamic Redox State-Related Parameters

Oxidative stress refers to an imbalance between oxidant and antioxidant molecules, which is usually associated with oxidative damage to biomolecules and mitochondrial malfunction. Redox state-related parameters include (1) the direct measurement of ROS, (2) the assessment of the antioxidant defense status, and (3) the analysis of the resulting oxidative damage to molecules. Directly measuring ROS appears to be the preferred method among scientists, but most ROS are extremely unstable and difficult to measure. The processes of determining both the oxidative damage to biomolecules and the antioxidant system status, although both are indirect approaches, provide a reliable method to measure oxidative stress on a given sample. Recently, the Seahorse XF and the Oroboros O2k systems have provided new insights into the redox state from a more dynamic point of view. These techniques assess mitochondrial oxidative phosphorylation function and bioenergetics on isolated mitochondria, cultured cells, or specific tissues such as permeabilized fibers. This review describes a range of methodologies to measure redox state-related parameters, their strengths, and their limitations. In conclusion, all these techniques are valid and none of them can be replaced by another. Indeed, they have the potential to complement each other for a complete evaluation of the redox state of a given sample.

Neuroprotective effect of liraglutide in an experimental mouse model of multiple sclerosis: role of AMPK/SIRT1 signaling and NLRP3 inflammasome

The heterogeneous nature of multiple sclerosis (MS) and the unavailability of treatments addressing its intricate network and reversing the disease state is yet an area that needs to be elucidated. Liraglutide, a glucagon-like peptide-1 analogue, recently exhibited intriguing potential neuroprotective effects. The currents study investigated its potential effect against mouse model of MS and the possible underlying mechanisms. Demyelination was induced in C57Bl/6 mice by cuprizone (400 mg/kg/day p.o.) for 5 weeks. Animals received either liraglutide (25 nmol/kg/day i.p.) or dorsomorphin, an AMPK inhibitor, (2.5 mg/Kg i.p.) 30 min before the liraglutide dose, for 4 weeks (starting from the second week). Liraglutide improved the behavioral profile in cuprizone-treated mice. Furthermore, it induced the re-myelination process through stimulating oligodendrocyte progenitor cells differentiation via Olig2 transcription activation, reflected by increased myelin basic protein and myelinated nerve fiber percentage. Liraglutide elevated the protein content of p-AMPK and SIRT1, in addition to the autophagy proteins Beclin-1 and LC3B. Liraglutide halted cellular damage as manifested by reduced HMGB1 protein and consequently TLR-4 downregulation, coupled with a decrease in NF-κB. Liraglutide also suppressed NLRP3 transcription. Dorsomorphin pre-administration indicated a possible interplay between AMPK/SIRT1 and NLRP3 inflammasome activation as it partially reversed liraglutide’s effects. Immunohistochemical examination of Iba⁺ microglia emphasized these findings. In conclusion, liraglutide exerts neuroprotection against cuprizone-induced demyelination via anti-inflammatory, autophagic flux activation, NLRP3 inflammasome suppression, and anti-apoptotic mechanisms, possibly mediated, at least in part, via AMPK/SIRT1, autophagy, TLR-4/ NF-κB/NLRP3 signaling.

Neuroprotective Effect of Glatiramer Acetate on Neurofilament Light Chain Leakage and Glutamate Excess in an Animal Model of Multiple Sclerosis

Axonal and neuronal pathologies are a central constituent of multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE), induced by the myelin oligodendrocyte glycoprotein (MOG) 35–55 peptide. In this study, we investigated neurodegenerative manifestations in chronic MOG 35–55 induced EAE and the effect of glatiramer acetate (GA) treatment on these manifestations. We report that the neuronal loss seen in this model is not attributed to apoptotic neuronal cell death. In EAE-affected mice, axonal damage prevails from the early disease phase, as revealed by analysis of neurofilament light (NFL) leakage into the sera along the disease duration, as well as by immunohistological examination. Elevation of interstitial glutamate concentrations measured in the cerebrospinal fluid (CSF) implies that glutamate excess plays a role in the damage processes inflicted by this disease. GA applied as a therapeutic regimen to mice with apparent clinical symptoms significantly reduces the pathological manifestations, namely apoptotic cell death, NFL leakage, histological tissue damage, and glutamate excess, thus corroborating the neuroprotective consequences of this treatment.

MedXercise: a promising strategy to promote remyelination

Multiple sclerosis is an inflammatory and demyelinating disease of the central nervous system. While remyelination facilitates functional recovery in animal models, it is limited in people with multiple sclerosis. Thus, multiple strategies have been put forth to promote remyelination, including exercise and medication. Exercise promotes the release of growth factors and induces protein-level changes, while remyelinating medications act through a variety of mechanisms to promote oligodendrocyte maturation within the lesion. In animal models, the combination of medication and exercise (Medication + eXercise = MedXercise) has an additive effect on remyelination and other pathological features of multiple sclerosis. In this review, we highlight the existing literature on the effects of exercise and medication on remyelination both independently and in combination.

Proteomics of Multiple Sclerosis: Inherent Issues in Defining the Pathoetiology and Identifying (Early) Biomarkers

Multiple Sclerosis (MS) is a demyelinating disease of the human central nervous system having an unconfirmed pathoetiology. Although animal models are used to mimic the pathology and clinical symptoms, no single model successfully replicates the full complexity of MS from its initial clinical identification through disease progression. Most importantly, a lack of preclinical biomarkers is hampering the earliest possible diagnosis and treatment. Notably, the development of rationally targeted therapeutics enabling pre-emptive treatment to halt the disease is also delayed without such biomarkers. Using literature mining and bioinformatic analyses, this review assessed the available proteomic studies of MS patients and animal models to discern (1) whether the models effectively mimic MS; and (2) whether reasonable biomarker candidates have been identified. The implication and necessity of assessing proteoforms and the critical importance of this to identifying rational biomarkers are discussed. Moreover, the challenges of using different proteomic analytical approaches and biological samples are also addressed.

Sildenafil Alleviates Murine Experimental Autoimmune Encephalomyelitis by Triggering Autophagy in the Spinal Cord

Multiple Sclerosis (MS) is a neuroinflammatory and chronic Central Nervous System (CNS) disease that affects millions of people worldwide. The search for more promising drugs for the treatment of MS has led to studies on Sildenafil, a phosphodiesterase type 5 Inhibitor (PDE5I) that has been shown to possess neuroprotective effects in the Experimental Autoimmune Encephalomyelitis (EAE), an animal model of MS. We have previously shown that Sildenafil improves the clinical score of EAE mice via modulation of apoptotic pathways, but other signaling pathways were not previously covered. Therefore, the aim of the present study was to further investigate the effects of Sildenafil treatment on autophagy and nitrosative stress signaling pathways in EAE. 24 female C57BL/6 mice were divided into the following groups: (A) Control - received only water; (B) EAE - EAE untreated mice; (C) SILD - EAE mice treated with 25mg/kg of Sildenafil s.c. The results showed that EAE mice presented a pro-nitrosative profile characterized by high tissue nitrite levels, lowered levels of p-eNOS and high levels of iNOS. Furthermore, decreased levels of LC3, beclin-1 and ATG5, suggests impaired autophagy, and decreased levels of AMPK in the spinal cord were also detected in EAE mice. Surprisingly, treatment with Sildenafil inhibited nitrosative stress and augmented the levels of LC3, beclin-1, ATG5, p-CREB and BDNF and decreased mTOR levels, as well as augmented p-AMPK. In conclusion, we propose that Sildenafil alleviates EAE by activating autophagy via the eNOS-NO-AMPK-mTOR-LC3-beclin1-ATG5 and eNOS-NO-AMPK-mTOR-CREB-BDNF pathways in the spinal cord.

Carnosine synthase deficiency is compatible with normal skeletal muscle and olfactory function but causes reduced olfactory sensitivity in aging mice

Carnosine (β-alanyl-l-histidine) and anserine (β-alanyl-3-methyl-l-histidine) are abundant peptides in the nervous system and skeletal muscle of many vertebrates. Many in vitro and in vivo studies demonstrated that exogenously added carnosine can improve muscle contraction, has antioxidant activity, and can quench various reactive aldehydes. Some of these functions likely contribute to the proposed anti-aging activity of carnosine. However, the physiological role of carnosine and related histidine-containing dipeptides (HCDs) is not clear. In this study, we generated a mouse line deficient in carnosine synthase (Carns1). HCDs were undetectable in the primary olfactory system and skeletal muscle of Carns1-deficient mice. Skeletal muscle contraction in these mice, however, was unaltered, and there was no evidence for reduced pH-buffering capacity in the skeletal muscle. Olfactory tests did not reveal any deterioration in 8-month-old mice lacking carnosine. In contrast, aging (18-24-month-old) Carns1-deficient mice exhibited olfactory sensitivity impairments that correlated with an age-dependent reduction in the number of olfactory receptor neurons. Whereas we found no evidence for elevated levels of lipoxidation and glycation end products in the primary olfactory system, protein carbonylation was increased in the olfactory bulb of aged Carns1-deficient mice. Taken together, these results suggest that carnosine in the olfactory system is not essential for information processing in the olfactory signaling pathway but does have a role in the long-term protection of olfactory receptor neurons, possibly through its antioxidant activity.

Autophagy in white matter disorders of the CNS: mechanisms and therapeutic opportunities

Autophagy is a constitutive process that degrades, recycles and clears damaged proteins or organelles, yet, despite activation of this pathway, abnormal proteins accumulate in neurons in neurodegenerative diseases and in oligodendrocytes in white matter disorders. Here, we discuss the role of autophagy in white matter disorders, including neurotropic infections, inflammatory diseases such as multiple sclerosis, and in hereditary metabolic disorders and acquired toxic‐metabolic disorders. Once triggered due to cell stress, autophagy can enhance cell survival or cell death that may contribute to oligodendrocyte damage and myelin loss in white matter diseases. For some disorders, the mechanisms leading to myelin loss are clear, whereas the aetiological agent and pathological mechanisms are unknown for other myelin disorders, although emerging studies indicate that a common mechanism underlying these disorders is dysregulation of autophagic pathways. In this review we discuss the alterations in the autophagic process in white matter disorders and the potential use of autophagy‐modulating agents as therapeutic approaches in these pathological conditions. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

Partially saturated canthaxanthin alleviates aging-associated oxidative stress in D-galactose administered male wistar rats

It has been earlier reported that partially saturated canthaxanthin (PSC) from Aspergillus carbonarius mutant is non-toxic, has anti-lipid peroxidation activity and can induce apoptosis in prostate cancer cell lines. In the present study, the antiaging effect of PSC was explored in D-galactose administered male wistar rats. 8-10 weeks old, male wistar rats were randomly divided into (i) Vehicle Control Group (VCG), (ii) Aged Control Group (ACG), (iii) Aged + α Lipoic Acid Group (ALG) and (iv) Aged + Partially saturated canthaxanthin Group (APG). Rats received D-galactose (300 mg /kg bwt/day; i.p.) alone (ACG) or together with PSC (APG) (20 mg/kg bwt/day; oral) and α Lipoic Acid (ALG) (80 mg/kg bwt/day; oral) for 10 weeks. Rats in VCG were injected with the same volume of physiological saline (i.p.) and fed with olive oil (vehicle). In vitro protein oxidation and DNA oxidation inhibition, in vivo malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), acetylcholinesterase (AChE) and monoamine oxidase (MAO) activities were determined. In addition, brain neurotransmitters, dopamine and serotonin were estimated by NMR. PSC treatment showed inhibition against protein and DNA oxidation. PSC effectively improved D-galactose induced aging rats by inducing a protective effect through up-regulation of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT) and brain neurotransmitters and downregulated malondialdehyde (MDA) and monoamineoxidase (MAO) levels. Thus, PSC appears to be a functional compound having antioxidant and antiaging properties.

Shikonin ameliorates experimental autoimmune encephalomyelitis (EAE) via immunomodulatory, anti-apoptotic and antioxidative activity

OBJECTIVES

Multiple sclerosis is a common autoimmune inflammatory disease of the central nervous system. There are several underlying mechanisms for the pathogenesis of the disease, including inflammation, oligodendrocyte apoptosis and oxidative stress.

METHODS

The mechanism of action of shikonin was investigated in the C57BL/6 experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis.

KEY FINDINGS

The results revealed that EAE induction significantly increased the extent of demyelination in the corpus callosum tissues of the animals, while treatment of the mice with shikonin significantly decreased the extent of demyelination. Real-time polymerase chain reaction-based analysis of the brain samples from the EAE mice revealed significant enhancement in the expression levels of tumour necrosis factor-α (TNF-α), interferon-γ (IFN-γ) and Bax genes as well as a reduction in the expression levels of transforming growth factor-ß (TGF-β) and Bcl2. But, shikonin treatment significantly reduced the expression levels of TNF-α, IFN-γ and Bax. On the other hand, the expression levels of TGF-β and Bcl2 as well as the activity of glutathione peroxidase-1 (GPX-1) enzyme were significantly increased following the shikonin treatment.

CONCLUSIONS

This study emphasized the immune-modulatory and antioxidative effects of shikonin, which may have an important healing effect on the severity of EAE.

Age-related oxidative modifications to uterine albumin impair extravillous trophoblast cells function

Advanced maternal age is associated not only with a significant reduction in fertility but also with an additional risk of developing pregnancy-related disorders. Most of these disorders are now believed to be the clinical manifestation of an incorrect placentation, namely deficient transformation of maternal spiral arteries and ineffective trophoblast invasion through uterine stroma. In the present study it was hypothesized that an age-related loss in uterine redox homeostasis interferes with the function of extravillous trophoblasts (EVTs) and placentation. To test this hypothesis, relative levels of oxidatively modified proteins were evaluated in human samples from placenta and placental bed, and the role of specific oxidative modifications to proteins in placentation was studied using a cell culture model of EVTs. In the placental bed, the carbonylation level of a 66 kDa protein (identified as albumin) presented a strong, positive and significant correlation with maternal age. Albumin was immunodetected preferentially in endothelial cells and connective tissue between muscle fascicles. In vitro results showed that carbonylated albumin overload did not alter cell viability, but reduced EVTs motility and triggered cell stress response pathways. Moreover, EVTs presented decreased ability to adhere to and invade a collagen extracellular matrix pre-treated with carbonylated albumin. In conclusion, reproductive ageing is accompanied by an increase in maternal uterine carbonylated albumin, that may have a deleterious role in the modulation of EVTs function.

Carbonyl-protein content increases in brain and blood of female rats after chronic oxycodone treatment

BACKGROUND

Opioids are the most effective drugs commonly prescribed to treat pain. Due to their addictive nature, opioid pain relievers are now second to marijuana, ahead of cocaine with respect to dependence. Ours and other studies suggest potential toxic effects of chronic opioid administration leading to neuronal degeneration. It has been suggested that protein carbonylation may represent a sensitive biomarker of cellular degeneration. To evaluate whether prolonged oxycodone administration is associated with accumulation of protein aggregates that may contribute to neuronal degeneration we measured protein carbonylation levels in brain and also in blood plasma of rats after 30-days of 15 mg/kg daily oxycodone administration.

RESULTS

We observed a significant increase in the level of carbonylated proteins in rat brain cortex after 30-days of oxycodone treatment compare to that in water treated animals. Also, oxycodone treated rats demonstrated accumulation of insoluble carbonyl-protein aggregates in blood plasma.

CONCLUSIONS

Our data suggests that tests detecting insoluble carbonyl-protein aggregates in blood may serve as an inexpensive and minimally invasive method to monitor neuronal degeneration in patients with a history of chronic opioid use. Such methods could be used to detect toxic side effects of other medications and monitor progression of aging and neurodegenerative diseases.

Suppression of the Peripheral Immune System Limits the Central Immune Response Following Cuprizone-Feeding: Relevance to Modelling Multiple Sclerosis

Cuprizone (CPZ) preferentially affects oligodendrocytes (OLG), resulting in demyelination. To investigate whether central oligodendrocytosis and gliosis triggered an adaptive immune response, the impact of combining a standard (0.2%) or low (0.1%) dose of ingested CPZ with disruption of the blood brain barrier (BBB), using pertussis toxin (PT), was assessed in mice. 0.2% CPZ(±PT) for 5 weeks produced oligodendrocytosis, demyelination and gliosis plus marked splenic atrophy (37%) and reduced levels of CD4 (44%) and CD8 (61%). Conversely, 0.1% CPZ(±PT) produced a similar oligodendrocytosis, demyelination and gliosis but a smaller reduction in splenic CD4 (11%) and CD8 (14%) levels and no splenic atrophy. Long-term feeding of 0.1% CPZ(±PT) for 12 weeks produced similar reductions in CD4 (27%) and CD8 (43%), as well as splenic atrophy (33%), as seen with 0.2% CPZ(±PT) for 5 weeks. Collectively, these results suggest that 0.1% CPZ for 5 weeks may be a more promising model to study the ‘inside-out’ theory of Multiple Sclerosis (MS). However, neither CD4 nor CD8 were detected in the brain in CPZ±PT groups, indicating that CPZ-mediated suppression of peripheral immune organs is a major impediment to studying the ‘inside-out’ role of the adaptive immune system in this model over long time periods. Notably, CPZ(±PT)-feeding induced changes in the brain proteome related to the suppression of immune function, cellular metabolism, synaptic function and cellular structure/organization, indicating that demyelinating conditions, such as MS, can be initiated in the absence of adaptive immune system involvement.

Reduced expression of the ferroptosis inhibitor glutathione peroxidase-4 in multiple sclerosis and experimental autoimmune encephalomyelitis

Glutathione peroxidase 4 (GPx4) is the only enzyme capable of reducing toxic lipid hydroperoxides in biological membranes to the corresponding alcohols using glutathione as the electron donor. GPx4 is the major inhibitor of ferroptosis, a non-apoptotic and iron-dependent programmed cell death pathway, which has been shown to occur in various neurological disorders with severe oxidative stress. In this study, we investigate whether GPx4 expression is altered in multiple sclerosis and its animal model experimental autoimmune encephalomyelitis (EAE). The results clearly show that mRNA expression for all three GPx4 isoforms (cytoplasmic, mitochondrial and nuclear) decline in multiple sclerosis gray matter and in the spinal cord of MOG_35-55 peptide-induced EAE. The amount of GPx4 protein is also reduced in EAE, albeit not in all cells. Neuronal GPx4 immunostaining, mostly cytoplasmic, is lower in EAE spinal cords than in control spinal cords, while oligodendrocyte GPx4 immunostaining, mainly nuclear, is unaltered. Neither control nor EAE astrocytes and microglia cells show GPx4 labeling. In addition to GPx4, two other negative modulators of ferroptosis (γ-glutamylcysteine ligase and cysteine/glutamate antiporter), which are critical to maintain physiological levels of glutathione, are diminished in EAE. The decrease in the ability to eliminate hydroperoxides was also evidenced by the accumulation of lipid peroxidation products and the reduction in the proportion of the docosahexaenoic acid in non-myelin lipids. These findings, along with presence of abnormal neuronal mitochondria morphology, which includes an irregular matrix, disrupted outer membrane and reduced/absent cristae, are consistent with the occurrence of ferroptotic damage in inflammatory demyelinating disorders.

Molecular Mechanisms of Phosphodiesterase-5 Inhibitors on Neuronal Apoptosis

Phosphodiesterase-5 inhibitors (PDE5Is) have been shown to modulate cell death/cell survival in different in vivo and in vitro models of disease by activating many signaling pathways. This review aimed at elucidating how PDE5Is can inhibit apoptosis. In this study, we describe many signaling pathways involved with the mechanism of action of PDE5Is that ultimately inhibit apoptosis and thus promote cell survival.

Advanced Glycation Endproducts Are Increased in the Animal Model of Multiple Sclerosis but Cannot Be Reduced by Pyridoxamine Treatment or Glyoxalase 1 Overexpression

Multiple sclerosis (MS) is a demyelinating autoimmune disease of the central nervous system (CNS). The immune response in MS patients leads to the infiltration of immune cells in the CNS and their subsequent activation. Immune cell activation induces a switch towards glycolysis. During glycolysis, the dicarbonyl product methylglyoxal (MGO) is produced. MGO is a glycating agent that can rapidly form advanced glycation endproducts (AGEs). In turn, AGEs are able to induce inflammatory responses. The glyoxalase system is the endogenous defense system of the body to reduce the burden of MGO thereby reducing AGE formation. This system consists of glyoxalase-1 and glyoxalase-2 which are able to detoxify MGO to D-lactate. We investigated whether AGE levels are induced in experimental autoimmune encephalitis (EAE), an inflammatory animal model of MS. Twenty seven days post EAE induction, MGO and AGE (N^ε-(carboxymethyl)lysine (CML), N^ε-(carboxyethyl)lysine (CEL), 5-hydro-5-methylimidazolone (MG-H1)) levels were significantly increased in the spinal cord of mice subjected to EAE. Yet, pyridoxamine treatment and glyoxalase-1 overexpression were unable to counteract AGE production during EAE and did not influence the clinical course of EAE. In conclusion, AGEs levels increase during EAE in the spinal cord, but AGE-modifying treatments do not inhibit EAE-induced AGE production and do not affect disease progression.

Absence of system xc- on immune cells invading the central nervous system alleviates experimental autoimmune encephalitis

BACKGROUND

Multiple sclerosis (MS) is an autoimmune demyelinating disease that affects the central nervous system (CNS), leading to neurodegeneration and chronic disability. Accumulating evidence points to a key role for neuroinflammation, oxidative stress, and excitotoxicity in this degenerative process. System x_c^- or the cystine/glutamate antiporter could tie these pathological mechanisms together: its activity is enhanced by reactive oxygen species and inflammatory stimuli, and its enhancement might lead to the release of toxic amounts of glutamate, thereby triggering excitotoxicity and neurodegeneration.

METHODS

Semi-quantitative Western blotting served to study protein expression of xCT, the specific subunit of system x_c^-, as well as of regulators of xCT transcription, in the normal appearing white matter (NAWM) of MS patients and in the CNS and spleen of mice exposed to experimental autoimmune encephalomyelitis (EAE), an accepted mouse model of MS. We next compared the clinical course of the EAE disease, the extent of demyelination, the infiltration of immune cells and microglial activation in xCT-knockout (xCT^-/-) mice and irradiated mice reconstituted in xCT^-/- bone marrow (BM), to their proper wild type (xCT^+/+) controls.

RESULTS

xCT protein expression levels were upregulated in the NAWM of MS patients and in the brain, spinal cord, and spleen of EAE mice. The pathways involved in this upregulation in NAWM of MS patients remain unresolved. Compared to xCT^+/+ mice, xCT^-/- mice were equally susceptible to EAE, whereas mice transplanted with xCT^-/- BM, and as such only exhibiting loss of xCT in their immune cells, were less susceptible to EAE. In none of the above-described conditions, demyelination, microglial activation, or infiltration of immune cells were affected.

CONCLUSIONS

Our findings demonstrate enhancement of xCT protein expression in MS pathology and suggest that system x_c^- on immune cells invading the CNS participates to EAE. Since a total loss of system x_c^- had no net beneficial effects, these results have important implications for targeting system x_c^- for treatment of MS.

Sex Difference in Oxidative Stress Parameters in Spinal Cord of Rats with Experimental Autoimmune Encephalomyelitis: Relation to Neurological Deficit

The study examined (a) whether there is sex difference in spinal cord and plasma oxidative stress profiles in Dark Agouti rats immunised for experimental autoimmune encephalomyelitis (EAE), the principal experimental model of multiple sclerosis, and (b) whether there is correlation between the oxidative stress in spinal cord and neurological deficit. Regardless of rat sex, with the disease development xanthine oxidase (XO) activity and inducible nitric oxide synthase (iNOS) mRNA expression increased in spinal cord, whereas glutathione levels decreased. This was accompanied by the rise in spinal cord malondialdehyde level. On the other hand, with EAE development superoxide dismutase (SOD) activity decreased, while O₂^- concentration increased only in spinal cord of male rats. Consequently, SOD activity was lower, whereas O₂^- concentration was higher in spinal cord of male rats with clinically manifested EAE. XO activity and iNOS mRNA expression were also elevated in their spinal cord. Consistently, in the effector phase of EAE the concentration of advanced oxidation protein product (AOPP) was higher in spinal cord of male rats, which exhibit more severe neurological deficit than their female counterparts. In as much as data obtained in the experimental models could be translated to humans, the findings may be relevant for designing sex-specific antioxidant therapeutic strategies. Furthermore, the study indicated that the increased pro-oxidant-antioxidant balance in plasma may be an early indicator of EAE development. Moreover, it showed that plasma AOPP level may indicate not only actual activity of the disease, but also serve to predict severity of its course.

Nrf2-dysregulation correlates with reduced synthesis and low glutathione levels in experimental autoimmune encephalomyelitis

This study investigates the possible mechanism(s) underlying glutathione (GSH) deficiency in the mouse spinal cord during the course of myelin oligodendrocyte glycoprotein35-55 peptide-induced experimental autoimmune encephalomyelitis (EAE), a commonly used animal model of multiple sclerosis. Using the classical enzymatic recycling method and a newly developed immunodot assay, we first demonstrated that total GSH levels (i.e. free GSH plus all its adducts) are reduced in EAE, suggesting an impaired synthesis. The decline in the levels of this essential antioxidant tripeptide in EAE coincides temporally and in magnitude with a reduction in the amount of γ-glutamylcysteine ligase, the rate-limiting enzyme in GSH synthesis. Other enzymes involved in GSH biosynthesis, whose genes also contain antioxidant-response elements, including glutathione synthetase, cystine/glutamate antiporter, and γ-glutamyl transpeptidase (γ-GT) are diminished in EAE as well. Low levels of γ-glutamylcysteine ligase, glutathione synthetase, and γ-GT are the consequence of reduced mRNA expression, which correlates with diminished expression of the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) in both the cytosol and nucleus. Interestingly, the low Nrf2 expression does not seem to be caused by increased degradation via Kelch-like ECH-associated protein 1-dependent or Kelch-like ECH-associated protein 1-independent mechanisms (such as glycogen synthetase kinase-3β activation), or by reduced levels of Nrf2 mRNA. This suggests that translation of this important transcription factor and/or other still unidentified post-translational processes are altered in EAE. These novel findings are central toward understanding how critical antioxidant and protective responses are lost in inflammatory demyelinating disorders.

Rutin Attenuates Hepatotoxicity in High-Cholesterol-Diet-Fed Rats

Background and Objective. High-cholesterol diet (HCD) intends to increase the oxidative stress in liver tissues inducing hepatotoxicity. Rutin is a natural flavonoid (vitamin p) which is known to have antioxidative properties. The aim of the present study was to investigate the potential effects of Rutin on hypercholesterolemia-induced hepatotoxicity in rats. Materials and Methods. Male Wistar rats were divided into four groups: G-I control, G-II Rutin, G-III HCD, and G-IV Rutin + HCD. The liver functions and lipid profile were used to evaluate the HCD-induced hepatotoxicity. Quantitative real time-PCR was carried out to evaluate the expression levels of genes in TGF-β/Smad signaling pathway. Results. Rutin in combination with HCD showed a significant protective effect against hepatotoxicity. HCD caused significant increase in the mRNA expression of transforming growth factor beta (TGF-β), Mothers Against Decapentaplegic Homolog 2 (Smad-2), Mothers Against Decapentaplegic Homolog 4 (Smad-4), Bcl-2-binding component 3 (Bbc3), caspase-3, P53 and Interleukin-6 (IL-6) and decrease in the expression levels of Cyclin depended kinase inhibitor (P21) and Interleukin-3 (IL-3) in hepatic cells. Conclusion. TGF-β/Smad signaling pathway is involved in HCD-induced hepatotoxicity and Rutin inhibits the hepatotoxicity via suppressing this pathway. Therefore, Rutin might be considered as a protective agent for hepatotoxicity.

Alternative source of stem cells derived from human periodontal ligament: a new treatment for experimental autoimmune encephalomyelitis

Background

Multiple sclerosis is a demyelinating disease mostly of autoimmune origin that affects and damages the central nervous system, leading to a disabling condition. The aim of the present study was to investigate whether administration of mesenchymal stem cells from human periodontal ligament (hPDLSCs) could ameliorate multiple sclerosis progression by exerting neuroprotective effects in an experimental model of autoimmune encephalomyelitis (EAE).

Methods

EAE was induced by immunization with myelin oligodendroglial glycoprotein peptide (MOG)_35–55 in C57BL/6 mice. After immunization, mice were observed every 48 hours for signs of EAE and weight loss. At the onset of disease, approximately 14 days after immunization, EAE mice were subjected to a single intravenous injection of hPDLSCs (10⁶ cells/150 μl) into the tail vein. At the point of animal sacrifice on day 56 after EAE induction, spinal cord and brain tissues were collected in order to perform histological evaluation, immunohistochemistry and western blotting analysis.

Results

Achieved results reveal that treatment with hPDLSCs may exert neuroprotective effects against EAE, diminishing both clinical signs and histological score typical of the disease (lymphocytic infiltration and demyelination) probably through the production of neurotrophic factors (results focused on brain-derived neurotrophic factor and nerve growth factor expression). Furthermore, administration of hPDLSCs modulates expression of inflammatory key markers (tumor necrosis factor-α, interleukin (IL)-1β, IL-10, glial fibrillary acidic protein, Nrf2 and Foxp3), the release of CD4 and CD8α T cells, and the triggering of apoptotic death pathway (data shown for cleaved caspase 3, p53 and p21).

Conclusions

In light of the achieved results, transplantation of hPDLSCs may represent a putative novel and helpful tool for multiple sclerosis treatment. These cells could have considerable implication for future therapies for multiple sclerosis and this study may represent the starting point for further investigations.

Role of autophagy in the pathogenesis of multiple sclerosis

Autophagy plays an important role in maintaining the cellular homeostasis. One of its functions is to degrade unnecessary organelles and proteins for energy recycling or amino-acids for cell survival. Ablation of autophagy leads to neurodegeneration. Multiple sclerosis (MS), a permanent neurological impairment typical of chronic inflammatory demyelinating disorder, is an auto-immune disease of the central nervous system (CNS). Autophagy is tightly linked to the innate and adaptive immune systems during the autoimmune process, and several studies have shown that autophagy directly participates in the progress of MS or experimental autoimmune encephalomyelitis (EAE, a mouse model of MS). Dysfunction of mitochondria that intensively influences the autophagy pathway is one of the important factors in the pathogenesis of MS. Autophagy-related gene (ATG) 5 and immune-related GTPase M (IRGM) 1 are increased, while ATG16L2 is decreased, in T-cells in EAE and active relapsing-remitting MS brains. Administration of rapamycin, an inhibitor of mammalian target of rapamycin ( mTOR), ameliorates relapsing-remitting EAE. Inflammation and oxidative stress are increased in MS lesions and EAE, but Lamp2 and the LC3-II/LC3-I ratio are decreased. Furthermore, autophagy in various glial cells plays important roles in regulating neuro-inflammation in the CNS, implying potential roles in MS. In this review, we discuss the role of autophagy in the peripheral immune system and the CNS in neuroinflammation associated with the pathogenesis of MS.

Nigella sativa amliorates inflammation and demyelination in the experimental autoimmune encephalomyelitis-induced Wistar rats

Multiple sclerosis (MS) is the major, immune-mediated, demyelinating neurodegenerative disease of the central nervous system (CNS). Experimental autoimmune encephalomyelitis (EAE) is a well-established animal model of MS. The aim of the present study was to investigate the protective and ameliorative effects of N. sativa seeds (2.8 g/kg body weight) in EAE-induced Wistar rats. EAE-induced rats were divided into: 1- EAE-induced rats ("EAE" group). 2- "N. sativa + EAE" group received daily oral administration of N. sativa 2 weeks prior EAE induction until the end of the experiment. 3- "EAE + N. sativa" group received daily oral administration of N. sativa after the appearance of first clinical signs until the end of the experiment. All animals were decapitated at the 28th day post EAE-induction. EAE was investigated using histopathological, immunohistochemical and ultrastructural examinations in addition to determination of some oxidative stress parameters in the cerebellum and medulla. N. sativa suppressed inflammation observed in EAE-induced rats. In addition, N. sativa enhanced remyelination in the cerebellum. Moreover, N. sativa reduced the expression of transforming growth factor beta 1 (TGF β1). N. sativa seeds could provide a promising agent effective in both the protection and treatment of EAE.

The control of reactive oxygen species production by SHP-1 in oligodendrocytes

We have previously described reduced myelination and corresponding myelin basic protein (MBP) expression in the central nervous system of Src homology 2 domain-containing protein tyrosine phosphatase 1 (SHP-1) deficient motheaten (me/me) mice compared with normal littermate controls. Deficiency in myelin and MBP expression in both brains and spinal cords of motheaten mice correlated with reduced MBP mRNA expression levels in vivo and in purified oligodendrocytes in vitro. Therefore, SHP-1 activity seems to be a critical regulator of oligodendrocyte gene expression and function. Consistent with this role, this study demonstrates that oligodendrocytes of motheaten mice and SHP-1-depleted N20.1 cells produce higher levels of reactive oxygen species (ROS) and exhibit corresponding markers of increased oxidative stress. In agreement with these findings, we demonstrate that increased production of ROS coincides with ROS-induced signaling pathways known to affect myelin gene expression in oligodendrocytes. Antioxidant treatment of SHP-1-deficient oligodendrocytes reversed the pathological changes in these cells, with increased myelin protein gene expression and decreased expression of nuclear factor (erythroid-2)-related factor 2 (Nrf2) responsive gene, heme oxygenase-1 (HO-1). Furthermore, we demonstrate that SHP-1 is expressed in human white matter oligodendrocytes, and there is a subset of multiple sclerosis subjects that demonstrate a deficiency of SHP-1 in normal-appearing white matter. These studies reveal critical pathways controlled by SHP-1 in oligodendrocytes that relate to susceptibility of SHP-1-deficient mice to both developmental defects in myelination and to inflammatory demyelinating diseases.

Decoding diffusivity in multiple sclerosis: analysis of optic radiation lesional and non-lesional white matter

Objectives

Diffusion tensor imaging (DTI) has been suggested as a new promising tool in MS that may provide greater pathological specificity than conventional MRI, helping, therefore, to elucidate disease pathogenesis and monitor therapeutic efficacy. However, the pathological substrates that underpin alterations in brain tissue diffusivity are not yet fully delineated. Tract-specific DTI analysis has previously been proposed in an attempt to alleviate this problem. Here, we extended this approach by segmenting a single tract into areas bound by seemingly similar pathological processes, which may better delineate the potential association between DTI metrics and underlying tissue damage.

Method

Several compartments were segmented in optic radiation (OR) of 50 relapsing-remitting MS patients including T2 lesions, proximal and distal parts of fibers transected by lesion and fibers with no discernable pathology throughout the entire length of the OR.

Results

Asymmetry analysis between lesional and non-lesional fibers demonstrated a marked increase in Radial Diffusivity (RD), which was topographically limited to focal T2 lesions and potentially relates to the lesional myelin loss. A relative elevation of Axial Diffusivity (AD) in the distal part of the lesional fibers was observed in a distribution consistent with Wallerian degeneration, while diffusivity in the proximal portion of transected axons remained normal. A moderate, but significant elevation of RD in OR non-lesional fibers was strongly associated with the global (but not local) T2 lesion burden and is probably related to microscopic demyelination undetected by conventional MRI.

Conclusion

This study highlights the utility of the compartmentalization approach in elucidating the pathological substrates of diffusivity and demonstrates the presence of tissue-specific patterns of altered diffusivity in MS, providing further evidence that DTI is a sensitive marker of tissue damage in both lesions and NAWM. Our results suggest that, at least within the OR, parallel and perpendicular diffusivities are affected by tissue restructuring related to distinct pathological processes.

Detection of protein aggregates in brain and cerebrospinal fluid derived from multiple sclerosis patients

Studies of the properties of soluble oligomer species of amyloidogenic proteins, derived from different proteins with little sequence homology, have indicated that they share a common structure and may share similar pathogenic mechanisms. Amyloid β, tau protein, as well as amyloid precursor protein normally associated with Alzheimer’s disease and Parkinson’s disease were found in lesions and plaques of multiple sclerosis patients. The objective of the study is to investigate whether brain and cerebrospinal fluid (CSF) samples derived from multiple sclerosis patients demonstrate the presence of soluble oligomers normally associated with protein-misfolding diseases such as Alzheimer’s disease. We have used anti-oligomer monoclonal antibodies to immunodetect soluble oligomers in CSF and brain tissues derived from multiple sclerosis patients. In this report, we describe the presence of soluble oligomers in the brain tissue and cerebral spinal fluid of multiple sclerosis patients detected with our monoclonal anti-oligomer antibodies with Western blot and Sandwich enzyme-linked immunosorbent assay (sELISA). These results might suggest that protein aggregation plays a role in multiple sclerosis pathogenesis although further and more refined studies are needed to confirm the role of soluble aggregates in multiple sclerosis.

Astaxanthin alleviates brain aging in rats by attenuating oxidative stress and increasing BDNF levels

Astaxanthin (AST) is a carotenoid pigment which possesses potent antioxidative, anti-inflammatory, and neuroprotective properties. The aim of this study was to investigate whether administration of AST had protective effects on D-galactose-induced brain aging in rats, and further examined its protective mechanisms. The results showed that AST treatment significantly restored the activities of glutathione peroxidase (GSH-PX) and superoxide dismutase (SOD), and increased glutathione (GSH) contents and total antioxidant capacity (T-AOC), but decreased malondialdehyde (MDA), protein carbonylation and 8-hydroxy-2- deoxyguanosine (8-OHdG) levels in the brains of aging rats. Furthermore, AST increased the ratio of Bcl-2/Bax, but decreased the expression of Cyclooxygenase-2 (COX-2) in the brains of aging rats. Additionally, AST ameliorated histopathological changes in the hippocampus and restored brain derived neurotrophic factor (BDNF) levels in both the brains and hippocampus of aging rats. These results suggested that AST could alleviate brain aging, which may be due to attenuating oxidative stress, ameliorating hippocampus damage, and upregulating BDNF expression.

Oxidative tissue injury in multiple sclerosis is only partly reflected in experimental disease models

Recent data suggest that oxidative injury may play an important role in demyelination and neurodegeneration in multiple sclerosis (MS). We compared the extent of oxidative injury in MS lesions with that in experimental models driven by different inflammatory mechanisms. It was only in a model of coronavirus-induced demyelinating encephalomyelitis that we detected an accumulation of oxidised phospholipids, which was comparable in extent to that in MS. In both, MS and coronavirus-induced encephalomyelitis, this was associated with massive microglial and macrophage activation, accompanied by the expression of the NADPH oxidase subunit p22phox but only sparse expression of inducible nitric oxide synthase (iNOS). Acute and chronic CD4⁺ T cell-mediated experimental autoimmune encephalomyelitis lesions showed transient expression of p22phox and iNOS associated with inflammation. Macrophages in chronic lesions of antibody-mediated demyelinating encephalomyelitis showed lysosomal activity but very little p22phox or iNOS expressions. Active inflammatory demyelinating lesions induced by CD8⁺ T cells or by innate immunity showed macrophage and microglial activation together with the expression of p22phox, but low or absent iNOS reactivity. We corroborated the differences between acute CD4⁺ T cell-mediated experimental autoimmune encephalomyelitis and acute MS lesions via gene expression studies. Furthermore, age-dependent iron accumulation and lesion-associated iron liberation, as occurring in the human brain, were only minor in rodent brains. Our study shows that oxidative injury and its triggering mechanisms diverge in different models of rodent central nervous system inflammation. The amplification of oxidative injury, which has been suggested in MS, is only reflected to a limited degree in the studied rodent models.

NQO1 gene rs1800566 variant is not associated with risk for multiple sclerosis

BACKGROUND

A possible role of oxidative stress in the pathogenesis of multiple sclerosis (MS) and in experimental autoimmune encephalomyelitis has been suggested. The detoxification enzyme NAD(P)H dehydrogenase, quinone 1 (NQO1) has been found up-regulated in MS lesions. A previous report described an association between the SNP rs1800566 in the NQO1 gene and the risk for MS in the Greek population. The aim of this study was to replicate a possible influence of the. SNP rs1800566 in the NQO1 gene in the risk for MS in the Spanish Caucasian population.

METHODS

We analyzed allelic and genotypic frequency of NQO1 rs1800566 in 290 patients with MS and 310 healthy controls, using TaqMan Assays.

RESULTS

NQO1 rs1800566 allelic and genotypic frequencies did not differ significantly between MS patients and controls, and were unrelated with age of onset of MS, gender, and clinical type of MS.

CONCLUSIONS

Our results indicate that NQO1 rs1800566 does not have an effect on MS disease risk.

Antiinflammatory activity of glucomoringin isothiocyanate in a mouse model of experimental autoimmune encephalomyelitis

Glucomoringin (4(α-L-rhamnosyloxy)-benzyl glucosinolate) (GMG) is an uncommon member of glucosinolate group belonging to the Moringaceae family, of which Moringa oleifera Lam. is the most widely distributed. Bioactivation of GMG with the enzyme myrosinase forms the corresponding isothiocyanate (4(α-L-rhamnosyloxy)-benzyl isothiocyanate) (GMG-ITC), which can play a key role in antitumoral activity and counteract the inflammatory response. The aim of this study was to assess the effect of GMG-ITC treatment in an experimental mouse model of multiple sclerosis (MS), an inflammatory demyelinating disease with neurodegeneration characterized by demyelinating plaques, neuronal, and axonal loss. For this reason, C57Bl/6 male mice were injected with myelin oligodendrocyte glycoprotein35-55 which is able to evoke an autoimmune response against myelin fibers miming human multiple sclerosis physiopatogenesis. Results clearly showed that the treatment was able to counteract the inflammatory cascade that underlies the processes leading to severe MS. In particular, GMG-ITC was effective against proinflammatory cytokine TNF-α. Oxidative species generation including the influence of iNOS, nitrotyrosine tissue expression and cell apoptotic death pathway was also evaluated resulting in a lower Bax/Bcl-2 unbalance. Taken together, this work adds new interesting properties and applicability of GMG-ITC and this compound can be suggested as a useful drug for the treatment or prevention of MS, at least in association with current conventional therapy.

Quetiapine fumarate for the treatment of multiple sclerosis: focus on myelin repair

Multiple sclerosis (MS) is a central nervous system disorder that is associated with progressive oligodendrocyte and neuronal loss, axonal degeneration, and demyelination. Several medications that mitigate immune abnormalities reduce both the frequency of relapses and inflammation on magnetic resonance imaging, leading to improved outcomes for people with the relapsing-remitting form of MS. However, there are no treatments for the progressive forms of MS where neurons and axons continue to degenerate; here, neuroprotective therapies, or medications that rebuild myelin to confer axonal well-being, may be useful. Quetiapine fumarate is an atypical antipsychotic with reported remyelinating and neuroprotective properties in inflammatory and noninflammatory models of demyelination, including experimental autoimmune encephalomyelitis, and both cuprizone- and global cerebral ischemia-induced demyelination. Preclinical studies suggest that quetiapine may exert these effects by stimulating proliferation and maturation of oligodendrocytes, releasing neurotrophic factors, increasing antioxidant defences, scavenging for free radicals, and inhibiting activated microglia, astrocytes, and T lymphocytes. Additionally, quetiapine may be beneficial for psychiatric and nonpsychiatric symptoms of MS including depression, anxiety, insomnia, and possibly even pain. These data indicate that clinical trials are justified to determine the safety, tolerability, and efficacy of quetiapine fumarate in MS.