Experimental Autoimmune Encephalomyelitis Rats Research Articles

NMDA Receptor Antagonist Memantine Ameliorates Experimental Autoimmune Encephalomyelitis in Aged Rats.

Aging is closely related to the main aspects of multiple sclerosis (MS). The average age of the MS population is increasing and the number of elderly MS patients is expected to increase. In addition to neurons, N-methyl-D-aspartate receptors (NMDARs) are also expressed on non-neuronal cells, such as immune cells. The aim of this study was to investigate the role of NMDARs in experimental autoimmune encephalomyelitis (EAE) in young and aged rats. Memantine, a non-competitive NMDAR antagonist, was administered to young and aged Dark Agouti rats from day 7 after immunization. Antagonizing NMDARs had a more favourable effect on clinical disease, reactivation, and apoptosis of CD4+ T cells in the target organ of aged EAE rats. The expression of the fractalkine receptor CX3CR1 was increased in memantine-treated rats, but to a greater extent in aged rats. Additionally, memantine increased Nrf2 and Nrf2-regulated enzymes' mRNA expression in brain tissue. The concentrations of superoxide anion radicals, malondialdehyde, and advanced oxidation protein products in brain tissue were consistent with previous results. Overall, our results suggest that NMDARs play a more important role in the pathogenesis of EAE in aged than in young rats.

Increased regulatory activity of intestinal innate lymphoid cells type 3 (ILC3) prevents experimental autoimmune encephalomyelitis severity

Experimental autoimmune encephalomyelitis (EAE) induced in inbred rodents, i.e., genetically identical animals kept under identical environmental conditions, shows variable clinical outcomes. We investigated such variations of EAE in Dark Agouti rats immunized with spinal cord homogenate and identified four groups: lethal, severe, moderate, and mild, at day 28 post immunization. Higher numbers of CD4+ T cells, helper T cells type 1 (Th1) and 17 (Th17) in particular, were detected in the spinal cord of the severe group in comparison with the moderate group. In addition, increased proportion of Th1 and Th17 cells, and heightened levels of interferon (IFN)-γ and interleukin (IL)-6 were detected in the small intestine lamina propria of the severe group. A selective agonist of free fatty acid receptor type 2 (Ffar2) applied orally in the inductive phase of EAE shifted the distribution of the disease outcomes towards milder forms. This effect was paralleled with potentiation of intestinal innate lymphoid cells type 3 (ILC3) regulatory properties, and diminished Th1 and Th17 cell response in the lymph nodes draining the site of immunization. Our results suggest that different clinical outcomes in DA rats are under determinative influence of intestinal ILC3 activity during the inductive phase of EAE.

The preferential effect of Clemastine on F3/Contactin-1/Notch-1 compared to Jagged-1/Notch-1 justifies its remyelinating effect in an experimental model of multiple sclerosis in rats

Clemastine (CLM) is repurposed to enhance remyelination in multiple sclerosis (MS) patients. CLM blocks histamine and muscarinic receptors as negative regulators to oligodendrocyte differentiation. These receptors are linked to the canonical and non-canonical Notch-1 signaling via specific ligands; Jagged-1 and F3/Contactin-1, respectively. Yet, there are no previous studies showing the influence of CLM on Notch entities. Herein, the study aimed to investigate to which extent CLM aligns to one of the two Notch-1 arms in experimental autoimmune encephalomyelitis (EAE) rat model. Three groups were utilized where first group received vehicles. The second group was injected by spinal cord homogenate mixed with complete Freund’s adjuvant on days 0 and 7. In the third group, CLM (5 mg/kg/day; p.o) was administered for 15 days starting from the day of the first immunization. CLM ameliorated EAE-associated motor and gripping impairment in rotarod, open-field, and grip strength arena beside sensory anomalies in hot plate, cold allodynia, and mechanical Randall-Selitto tests. Additionally, CLM alleviated depressive mood observed in tail suspension test. These findings harmonized with histopathological examinations of Luxol-fast blue stain together with enhanced immunostaining of myelin basic protein and oligodendrocyte lineage gene 2 in corpus callosum and spinal cord. Additionally, CLM enhanced oligodendrocyte myelination and maturation by increasing 2′,3′-cyclic nucleotide 3′-phosphodiesterase, proteolipid protein, aspartoacylase as well. CLM restored the level of F3/Contactin-1 in the diseased rats over Jagged-1 level; the ligand of the canonical pathway. This was accompanied by elevated gene expression of Deltex-1 and reduced hairy and enhancer-of-split homologs 1 and 5. Additionally, CLM suppressed microglial and astrocyte activation via reducing the expression of ionized calcium-binding adaptor molecule-1 as well as glial fibrillary acidic protein, respectively. These results outlined the remyelinating beneficence of CLM which could be due to augmenting the non-canonical Notch-1 signaling over the canonical one.

Roflumilast: Modulating neuroinflammation and improving motor function and depressive symptoms in multiple sclerosis

BackgroundMultiple sclerosis (MS) is an autoimmune disease causing central nervous system demyelination, often associated with depression. Current treatments for MS do not effectively address both physical disability and depression. Roflumilast, a phosphodiesterase-4 inhibitor with anti-inflammatory properties, has shown promise for autoimmune diseases. MethodsWe used an experimental autoimmune encephalomyelitis (EAE) rat model to study roflumilast's effects. Motor dysfunction and depression symptoms were assessed, and histopathological analysis evaluated its anti-inflammatory properties. Flow cytometry examined the drug's impact on brain microglia. TNF-α, IL-1β, and IL-6 levels in hippocampal tissue were assessed using ELISA kits. ResultsRoflumilast improved motor dysfunction and depression symptoms in EAE rats. Histopathological analysis revealed reduced inflammation, demyelination, and axonal loss in the spinal cord. Roflumilast suppressed microglial cell activation and conversion to pro-inflammatory M1-type cells. Flow cytometry showed roflumilast inhibited inflammatory marker expression in microglia and their activation in the hippocampus. IL-6 was identified as a roflumilast target for suppressing hippocampal inflammation. LimitationsThis study used an animal model and did not assess long-term or potential side effects of roflumilast treatment. ConclusionsRoflumilast holds promise as a treatment for depression and motor impairment in MS. Its anti-inflammatory properties, reducing inflammation and inhibiting microglial activation, suggest its potential for MS therapy. However, further research is needed to evaluate long-term effects and safety in MS patients.

C-Terminal Region of Caveolin-3 Contains a Stretch of Amino Acid Residues Capable of Diminishing Symptoms of Experimental Autoimmune Encephalomyelitis but Not Rheumatoid Arthritis Modeled in Rats.

A short synthetic peptide from the C-terminal part of the caveolin-3 structure was tested for experimental autoimmune encephalomyelitis (EAE) treatment in rats. The structure-function similarity established between the novel synthetic peptide of pCav3 and the well-known immunomodulator immunocortin determined pCav3's ability to reduce EAE symptoms in Dark Agouti (DA) rats injected with pCav3 (500 µg/kg). pCav3 was found to interfere with the proliferation of lymphocytes extracted from the LNs of DA rats primed with homogenate injection, with IC50 = 0.42 μM (2.35 mcg/mL). pCav3 affected EAE in a very similar manner as immunocortin. The high degree of homology between the amino acid sequences of pCav3 and immunocortin corresponded well with the therapeutic activities of both peptides, as demonstrated on EAE. The latter peptide, possessing a homologous structure to pCav3, was also tested on EAE to explore whether there were structural restrictions between these peptides implied by the MHC-involved cell machinery. Consequently, immunocortin was further examined with a different autoimmune disease model, collagen-induced arthritis (CIA), established in Sprague-Dawley rats. CIA was established using an intentionally different genetic platform than EAE. Based on the results, it was concluded that the effectiveness of pCav3 and immunocortin peptides in EAE rat model was almost identical, but differed in the rat model of rheumatoid arthritis; thus, efficacy may be sensitive to the MHC type of animals used to establish the autoimmune disease model.

2-Methoxyestradiol-3,17-O,O-bis-sulfamate inhibits store-operated Ca2+ entry in T lymphocytes and prevents experimental autoimmune encephalomyelitis.

Ca2+ signaling is one of the essential signaling systems for T lymphocyte activation, the latter being an essential step in the pathogenesis of autoimmune diseases such as multiple sclerosis (MS). Store-operated Ca2+ entry (SOCE) ensures long lasting Ca2+ signaling and is of utmost importance for major downstream T lymphocyte activation steps, e.g. nuclear localization of the transcription factor 'nuclear factor of activated T cells' (NFAT). 2-Methoxyestradiol (2ME2), an endogenous metabolite of estradiol (E2), blocks nuclear translocation of NFAT. The likely underlying mechanism is inhibition of SOCE, as shown for its synthetic sulfamate ester analogue 2-ethyl-3-sulfamoyloxy-17β-cyanomethylestra-1,3,5(10)-triene (STX564). Here, we demonstrate that another synthetic bis-sulfamoylated 2ME2 derivative, 2-methoxyestradiol-3,17-O,O-bis-sulfamate (2-MeOE2bisMATE, STX140), an orally bioavailable, multi-targeting anticancer agent and potent steroid sulfatase (STS) inhibitor, antagonized SOCE in T lymphocytes. Downstream events, e.g. secretion of the pro-inflammatory cytokines interferon-γ and interleukin-17, were decreased by STX140 in in vitro experiments. Remarkably, STX140 dosed in vivo completely blocked the clinical disease in both active and transfer experimental autoimmune encephalomyelitis (EAE) in Lewis rats, a T cell-mediated animal model for MS, at a dose of 10 mg/kg/day i.p., whereas neither 2ME2 nor Irosustat, a pure STS inhibitor, showed any effect. The STS inhibitory activity of STX140 is therefore not responsible for its activity in this model. Taken together, inhibition of SOCE by STX140 resulting in full antagonism of clinical symptoms in EAE in the Lewis rat, paired with the known excellent bioavailability and pharmaceutical profile of this drug, open potentially new therapeutic avenues for the treatment of MS.

Electrophysiological and Histological Correlations of Optic Neuritis in the Dark Agouti Rat Model of Experimental Autoimmune Encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) is an animal model of Inflammatory central nervous system (CNS) disease. Dark agouti (DA) rats immunized with full-length myelin oligodendrocyte glycoprotein (MOG1-125) typically develop a relapsing-remitting EAE form characterized by predominant demyelinating involvement of the spinal cord and optic nerve. Visually evoked potentials (VEP) are a useful objective tool to assess the optic nerve function and monitor electrophysiological changes in optic neuritis (ON). The current study aimed to assess the VEP changes in MOG-EAE DA rats using a minimally invasive recording device and to correlate them with histological findings. Twelve MOG-EAE DA rats and four controls underwent VEP recording at day 0, 7, 14, 21, and 28 post-EAE induction. Tissue samples were obtained on days 14, 21, and 28 from two EAE rats and one control. The median VEP latencies were significantly higher on days 14, 21, and 28 compared to baseline, with maximal latencies observed on day 21. The histological analyses on day 14 demonstrated inflammation with largely preserved myelin and axonal structures. Inflammation and demyelination with largely preserved axons were evident on days 21 and 28, which correlated with prolonged VEP latencies. These findings suggest that VEPs may be a reliable biomarker reflecting the optic nerve involvement in EAE. Moreover, the use of a minimally invasive device enables observation of VEP changes over time in MOG-EAE DA rats. Our findings may have important implications for testing the potential neuroprotective and regenerative effects of new therapies for CNS demyelinating diseases.

Additive beneficial effects of aerobic training and royal jelly on hippocampal inflammation and function in experimental autoimmune encephalomyelitis rats.

Although the beneficial role of training and the use of some antioxidants in physiological and psychological disorders in autoimmune diseases has been reported, the simultaneous effect of aerobic training (AT) and royal jelly (RJ) with different doses is not well understood. The present study aimed to investigate the impact of AT and RJ on inflammatory factors in the hippocampus, as well as depression and anxiety in the experimental autoimmune encephalomyelitis (EAE). Sprague-Dawley rats with EAE were assigned to seven groups: (1) EAE without any other intervention (EAE); (2) sham, receiving normal saline (Sh); (3) 50mg/kg RJ (RJ50); (4) 100mg/kg RJ (RJ100); (5) AT; (6) AT+RJ50; and (7) AT+RJ100. In addition, a healthy control group was assessed. EAE significantly increased interleukin 17 (IL-17), transforming growth factor-β (TGF-β) gene expression and immobilization time as well as anxiety and depression indices, and significantly decreased interleukin 10 (IL-10), compared to the control group. AT decreased significantly IL-17, TGF-β gene expression and immobilization time as well as anxiety and depression indices, while it significantly increased IL-10, compared to the EAE group. RJ50 and RJ100 decreased significantly IL-17, IL-23 gene expression, anxiety and depression indices, and significantly increased IL-10 compared to the EAE group. AT+RJ50 and AT+RJ100 significantly decreased IL-17, IL-23, and TGF-β and as well as anxiety and depression indices while significantly increasing IL-10 compared to the EAE group. The effects of AT+RJ100 on significant decreasing IL-17, IL-23, anxiety and depression and increasing TGF-β, IL-10 were more favorable than RJ50. AT and RJ improved inflammatory and regulatory factors of autoimmunity and reduced anxiety and depression. The RJ combined with AT induced additive effects while using RJ100 was more favorable than RJ50.

Modulation of p38 MAPK and Nrf2/HO-1/NLRP3 inflammasome signaling and pyroptosis outline the anti-neuroinflammatory and remyelinating characters of Clemastine in EAE rat model

There is vast evidence for the effect of NOD-like receptor protein-3 (NLRP3) inflammasome on multiple sclerosis (MS) pathogenesis. Clemastine (CLM) targets NLRP3 in hypoxic brain injury and promotes oligodendrocyte differentiation. However, no previous study pointed to the link of CLM with inflammasome components in MS. Herein, the study aimed to verify the action of CLM on NLRP3 signaling in experimental autoimmune encephalomyelitis (EAE) as an MS rat model. Homogenate of spinal cord with complete Freund’s adjuvant was administered on days 0 and 7 to induce EAE. Rats received either CLM (5 mg/kg/day; p.o.) or MCC950 (2.5 mg/kg/day; i.p) for 15 days starting from the first immunization day. In EAEs’ brains, NLRP3 pathway components; total and phosphorylated p38 mitogen-activated protein kinase (MAPK), apoptosis-associated speck-like protein containing a CARD (ASC), caspase-1, interleukins 1β and −18 along with pyroptotic marker; gasdermin D (GSDMD) were upregulated. These were accompanied with diminished nuclear factor erythroid 2–related factor 2 (Nrf2), heme oxygenase-1 (HO-1) and total antioxidant capacity levels. CLM improved these perturbations as well as signs of MS; weight loss, clinical scores, and motor disorders observed in the open field, hanging wire and rotarod tests. Histopathological examinations revealed improvement in H&E abnormalities and axonal demyelination as shown by luxol fast blue stain in lumbar sections of spinal cord. These CLM’s actions were studied in comparison to MCC950 as a well-established selective blocker of the NLRP3 inflammasome. Conclusively, CLM has a protective role against neuroinflammation and demyelination in EAE via its anti-inflammatory and anti-pyroptotic actions.

The protective effect of total glucosides of white paeony capsules on experimental autoimmune encephalomyelitis

AimsTo learn about the effect and mechanism of total glucosides of white peony capsule (TGP), on experimental autoimmune encephalomyelitis (EAE), an acknowledged animal model of multiple sclerosis (MS). MethodsThe rat model of EAE was induced by subcutaneous injection with guinea pig spinal cord homogenate. The severity of the disease model was assessed by clinical score, hematoxylin and eosin (H&E) and luxol fast blue (LFB). Immunohistochemical assay was used to observe the types of inflammatory cells and adhesive molecule expression. Enzyme-linked immunosorbent assay (ELISA) was applied to detect content of the stem cell growth factor / mast cell growth factor (scf/MGF), interleukin-6 (IL-6) and IL-2. Immunofluorescence assay was applied to observe the expression of connexin43 (Cx43), glial fibrillary acidic protein (GFAP), connexin47 (Cx47) and the monoclonal antibody anti-adenomatous polyposis coli (APC) clone CC1. ResultsCompare with the animals in EAE model group, TGP treated rats (particularly those treated with high doses) showed a significant decrease in morbidity, clinical scores, CNS infiltration of inflammatory cells (including mononuclear macrophages, CD4+ and CD8+ T cells) and demyelination. The key adhesion molecule ICAM-1, cytokines IL-2、IL-6 and scf/MGF were significantly decreased with TGP treatment. Oppositely, PD-1, connexin47 in oligodendrocytes and connexin43 in astrocytes were elevated with TGP treatment. ConclusionTo sum up, TGP exhibited a significantly prevention and treatment effect on EAE rat model, and this improvement was achieved through a combination way composed of glial and inflammatory cells, junction proteins, various factors including adhesion factors, interleukins and scf/MGF.

The Effect of Exercise Training and Royal Jelly on Hippocampal Cannabinoid-1-Receptors and Pain Threshold in Experimental Autoimmune Encephalomyelitis in Rats as Animal Model of Multiple Sclerosis.

Cannabinoid-1-receptors (CB1R) are therapeutic targets for both the treatment of autoimmune diseases, such as multiple sclerosis (MS), and some related symptoms such as pain. The aim of this study was to evaluate the effect of aerobic training and two dosages of royal jelly (RJ) on hippocampal CB1R and pain threshold (PT) in an experimental autoimmune encephalomyelitis (EAE) model. To this end, 56 female Sprague-Dawley rats with EAE were randomly assigned to one of the following eight conditions: (1) EAE; (2) sham; (3) 50 mg/kg RJ (RJ50); (4) 100 mg/kg RJ (RJ100); (5) exercise training (ET); (6) ET + RJ50; (7) ET + RJ100; and (8) not EAE or healthy control (HC). Endurance training was performed for five weeks, four sessions per week at a speed of 11–15 m/min for 30 min, and RJ was injected peritoneally at doses of 50 and 100 mg/kg/day). One-way analysis of variance and Tukey’s post hoc tests were performed to identify group-related differences in pain threshold (PT) and CB1R gene expression. Endurance training had no significant effect on PT and hippocampal CB1R in rats with EAE. CB1R gene expression levels in the RJ100 group were higher than in the EAE group. Further, PT levels in the ETRJ50 and ETRJ100 groups were higher than in the EAE group. The combination of ET and RJ50 had a higher impact on PT and CB1R, when compared to the ET and RJ50 alone. Next, there was a dose-response between RJ-induced CB1R gene expression and RJ dosages: higher dosages of RJ increased the CB1R gene expression. The overall results suggest that the combination of ET and increasing RJ dosages improved pain threshold probably related to CB1R in an EAE model, while this was not observed for ET or RJ alone.

Lactose and Casein Cause Changes on Biomarkers of Oxidative Damage and Dysbiosis in an Experimental Model of Multiple Sclerosis.

Experimental Autoimmune Encephalomyelitis (EAE) in rats closely reproduces Multiple Sclerosis (MS), a disease characterized by neuroinflammation and oxidative stress that also appears to extend to other organs and their compartments. The origin of MS is a matter for discussion, but it would seem that altering certain bacterial populations present in the gut may lead to a proinflammatory condition due to the bacterial Lipopolysaccharides (LPS) in the so-called brain-gut axis. The casein and lactose in milk confer anti-inflammatory properties and immunomodulatory effects. The objectives of this study were to evaluate the effects of administration of casein and lactose on the oxidative damage and the clinical status caused by EAE and to verify whether both casein and lactose had any effect on the LPS and its transport protein -LBP-. Twenty male Dark Agouti rats were divided into control rats (control), EAE rats, and EAE rats, to which casein and lactose, EAE+casein, and EAE+lactose, respectively, were administered. Fifty-one days after casein and lactose administration, the rats were sacrificed, and different organs were studied (brain, spinal cord, blood, heart, liver, kidney, small, and large intestine). In the latter, products derived from oxidative stress were studied (lipid peroxides and carbonylated proteins) as well as the glutathione redox system, various inflammation factors (total nitrite, Nuclear Factor-kappa B p65, the Rat Tumour Necrosis Factor-α), and the LPS and LBP values. Casein and lactose administration improved the clinical aspect of the disease at the same time as reducing inflammation and oxidative stress, exerting its action on the glutathione redox system, or increasing GPx levels.

Phenethyl ester of rosmarinic acid ameliorates experimental autoimmune encephalomyelitis

Rosmarinic acid is a polyphenolic compound, abundantly present in herbs of the Lamiaceae family. The aim of the study was to evaluate the immunomodulatory properties of a recently developed phenethyl ester derivative of rosmarinic acid (PERA), with enhanced ability of diffusion through biological membranes, in an animal model of the central nervous system (CNS) autoimmunity. To this end, experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis was used. Daily subcutaneous administration of PERA (30 mg/kg) from day 7 to day 22 after immunization successfully ameliorated EAE induced in Dark Agouti rats, shortening the disease duration and reducing maximal, cumulative and mean clinical score. PERA efficiently reduced production of major encephalitogenic cytokines, interferon (IFN)-γ and interleukin (IL)-17, in immune cells from the CNS or the lymph nodes draining the site of immunization of EAE rats, as well as in CD4+ T cells purified from the lymph nodes. Also, PERA inhibited NO production in the CNS and the lymph nodes, as well as in macrophages and microglial cells. Finally, microglial ability to produce pro-inflammatory cytokines IL-6, and tumor necrosis factor (TNF) were also reduced by PERA. Our results clearly imply that PERA possesses anti-encephalitogenic properties. Thus, further studies on the relevance of the observed effects for the therapy of multiple sclerosis are warranted.

β-Adrenoceptor Blockade Moderates Neuroinflammation in Male and Female EAE Rats and Abrogates Sexual Dimorphisms in the Major Neuroinflammatory Pathways by Being More Efficient in Males.

Our previous studies showed more severe experimental autoimmune encephalomyelitis (EAE) in male compared with female adult rats, and moderating effect of propranolol-induced β-adrenoceptor blockade on EAE in females, the effect associated with transcriptional stimulation of Nrf2/HO-1 axis in spinal cord microglia. This study examined putative sexual dimorphism in propranolol action on EAE severity. Propranolol treatment beginning from the onset of clinical EAE mitigated EAE severity in rats of both sexes, but to a greater extent in males exhibiting higher noradrenaline levels and myeloid cell β2-adrenoceptor expression in spinal cord. This correlated with more prominent stimulatory effects of propranolol not only on CX3CL1/CX3CR1/Nrf2/HO-1 cascade, but also on Stat3/Socs3 signaling axis in spinal cord microglia/myeloid cells (mirrored in the decreased Stat3 and the increased Socs3 expression) from male rats compared with their female counterparts. Propranolol diminished the frequency of activated cells among microglia, increased their phagocyting/endocyting capacity, and shifted cytokine secretory profile of microglia/blood-borne myeloid cells towards an anti-inflammatory/neuroprotective phenotype. Additionally, it downregulated the expression of chemokines (CCL2, CCL19/21) driving T-cell/monocyte trafficking into spinal cord. Consequently, in propranolol-treated rats fewer activated CD4+ T cells and IL-17+ T cells, including CD4+IL17+ cells coexpressing IFN-γ/GM-CSF, were recovered from spinal cord of propranolol-treated rats compared with sex-matched saline-injected controls. All the effects of propranolol were more prominent in males. The study as a whole disclosed that sexual dimorphism in multiple molecular mechanisms implicated in EAE development may be responsible for greater severity of EAE in male rats and sexually dimorphic action of substances affecting them. Propranolol moderated EAE severity more effectively in male rats, exhibiting greater spinal cord noradrenaline (NA) levels and myeloid cell β2-adrenoceptor (β2-AR) expression than females. Propranolol affected CX3CR1/Nrf2/HO-1 and Stat3/Socs3 signaling axes in myeloid cells, favored their anti-inflammatory/neuroprotective phenotype and, consequently, reduced Th cell reactivation and differentiation into highly pathogenic IL-17/IFN-γ/GM-CSF-producing cells.

Beneficial Effect of Melatonin Alone or in Combination with Glatiramer Acetate and Interferon β-1b on Experimental Autoimmune Encephalomyelitis.

Experimental autoimmune encephalomyelitis (EAE) is a relevant animal model of multiple sclerosis (MS). Oxidative stress and chronic inflammation play a major role in the pathogenesis of MS and EAE. Melatonin, a neurohormone, has potent anti-inflammatory properties. The aim of our study was to assess the therapeutic properties of melatonin alone or in combination with interferon β-1b (IFNβ-1b) or glatiramer acetate (GA) on EAE. EAE was induced in male Sprague-Dawley rats with an intraperitoneal injection of a homogenate of spinal cord and pig brain. At day 10 post immunization, rats were euthanized, and their brains were immediately excised and processed to measure oxidative stress markers and membrane fluidity. In addition, proinflammatory cytokines were quantified in plasma. Melatonin alone or in combination with GA and IFNβ-1b inhibited the disease process of EAE and the synthesis of proinflammatory cytokines, caused a significant decrement in oxidative stress markers, and preserved the membrane fluidity in the motor cortex, midbrain, and spinal cord. The cumulative index score was significantly reduced in EAE rats treated with melatonin alone or in combination with GA and IFNβ-1b. In conclusion, our findings provide preclinical evidence for the use of melatonin as an adjuvant therapeutic treatment for MS.

Vitamin B Complex and Experimental Autoimmune Encephalomyelitis -Attenuation of the Clinical Signs and Gut Microbiota Dysbiosis.

The present study aimed to investigate the neuroprotective effects of the vitamin B complex (B1, B2, B3, B5, B6, and B12—VBC), by studying the changes in the femoral nerve, quadriceps muscle, popliteal lymph nodes and gut microbiota in the rat model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE). VBC treatment attenuated clinical signs of EAE during the disease, and reduced the duration of EAE thereby contributing to a faster recovery. In VBC-treated EAE rats, a significant decrease in nerve and muscle nuclear density was revealed during the onset period of the disease, while a marked increase was detected at the end of the disease, compared with untreated EAE rats. In the lymph nodes of VBC-treated EAE rats, a fewer number of lymphoid follicles in the cortical area and smaller epithelioid granulomas were detected. The changes in microbiota composition were examined using 16S rRNA gene sequencing and bioinformatics analysis, which revealed the potential of VBC treatment in establishing and/or maintaining gut microbiota homeostasis. Finally, the present study demonstrated that VBC treatment ameliorated the cellular changes in the affected peripheral nerve, muscles innervated by this nerve, and the gut microbiota dysbiosis which occurred during the EAE.

Cornuside ameliorated experimental autoimmune encephalomyelitis by limiting the recruitment of CD4+ T lymphocytes in the spinal cord

We conducted this study to determine whether cornuside could improve the neurological deficit symptoms of experimental autoimmune encephalomyelitis (EAE) rats, as well as determine the potential involvement of CD4+ T lymphocytes, vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and tumor necrosis factor-α (TNF-α). Altogether, 32 Lewis rats were randomly divided into control, EAE, EAE/prednisolone, and EAE/cornuside, wherein their neurological function was assessed every day. CD4+ T lymphocyte recruitment into the spinal cord (SC) was evaluated using immunohistochemistry. The VCAM-1, ICAM-1 and TNF-α mRNA expressions in the SC were determined by real-time quantitative PCR, and the VCAM-1 and ICAM-1 proteins were determined by western blotting. Compared to the control group, the EAE group rats with neurological deficits had enhanced CD4+ T lymphocyte infiltration and higher expression levels of VCAM-1, ICAM-1, and TNF-α in the SC. Meanwhile, compared with the EAE group, the EAE/cornuside and EAE/prednisolone groups had lower neurological scores, less CD4+ T lymphocyte infiltrations, and lower expression levels of VCAM-1, ICAM-1, and TNF-α in the SC. Thus, cornuside ameliorated EAE, which could be owed to the inhibition of CD4+ T lymphocyte recruitment and VCAM-1, ICAM-1, and TNF-α expressions in the SC.

A biocompatible and injectable hydrogel to boost the efficacy of stem cells in neurodegenerative diseases treatment

AimsStem cell therapies emerged as treatment modalities with potential to cure neurodegenerative diseases (NDs). However, despite high expectations, their clinical use is still limited. Critical issues in treatment outcomes may be related to stem cells formulation and administration route. We develop a hydrogel as a cell carrier, consisting of compounds (phospholipids and hyaluronic acid-HA) naturally present in the central nervous system (CNS). The HA-based hydrogel physically crosslinked with liposomes is designed for direct injection into the CNS to significantly increase the bone marrow mesenchymal stem cells (BMSCs) bioavailability. Materials and methodsHydrogel compatibility is confirmed in vitro with BMSCs and in vivo through its intracerebroventricular injection in rats. To assess its efficacy, the main cause of chronic neurologic disability in young adults is selected, namely multiple sclerosis (MS). The efficacy of the developed formulation containing a lower number of cells than previously reported is demonstrated using an experimental autoimmune encephalomyelitis (EAE) rat model. Key findingsThe distribution of the engineered hydrogel into corpus callosum can be ideal for NDs treatment, since damage of this white matter structure is responsible for important neuronal deficits. Moreover, the BMSCs-laden hydrogel significantly decreases disease severity and maximum clinical score and eliminated the relapse. SignificanceThe engineering of advanced therapies using this natural carrier can result in efficacious treatments for MS and related debilitating conditions.

Memantine Modulates Oxidative Stress in the Rat Brain following Experimental Autoimmune Encephalomyelitis.

Experimental autoimmune encephalomyelitis (EAE) is an animal model most commonly used in research on the pathomechanisms of multiple sclerosis (MS). The inflammatory processes, glutamate excitotoxicity, and oxidative stress have been proposed as determinants accompanying demyelination and neuronal degeneration during the course of MS/EAE. The aim of the current study was to characterize the role of NMDA receptors in the induction of oxidative stress during the course of EAE. The effect of memantine, the uncompetitive NMDA receptor antagonist, on modulation of neurological deficits and oxidative stress in EAE rats was analyzed using several experimental approaches. We demonstrated that the expression of antioxidative enzymes (superoxide dismutases SOD1 and SOD2) were elevated in EAE rat brains. Under the same experimental conditions, we observed alterations in oxidative stress markers such as increased levels of malondialdehyde (MDA) and decreased levels of sulfhydryl (-SH) groups, both protein and non-protein (indicating protein damage), and a decline in reduced glutathione. Importantly, pharmacological inhibition of ionotropic NMDA glutamate receptors by their antagonist memantine improved the physical activity of EAE rats, alleviated neurological deficits such as paralysis of tail and hind limbs, and modulated oxidative stress parameters (MDA, -SH groups, SOD’s). Furthermore, the current therapy aiming to suppress NMDAR-induced oxidative stress was partially effective when NMDAR’s antagonist was administered at an early (asymptomatic) stage of EAE.

Piperine Improves Experimental Autoimmune Encephalomyelitis (EAE) in Lewis Rats Through its Neuroprotective, Anti-inflammatory, and Antioxidant Effects.

Inflammation, demyelination, glial activation, and oxidative damage are the most pathological hallmarks of multiple sclerosis (MS). Piperine, a main bioactive alkaloid of black pepper, possesses antioxidant, anti-inflammatory, and neuroprotective properties whose therapeutic potential has been less studied in the experimental autoimmune encephalomyelitis (EAE) models. In this study, the efficiency of piperine on progression of EAE model and myelin repair mechanisms was investigated. EAE was induced in female Lewis rats and piperine and its vehicle were daily administrated intraperitoneally from day 8 to 29 post immunization. We found that piperine alleviated neurological deficits and EAE disease progression. Luxol fast blue and H&E staining and immunostaining of lumbar spinal cord cross sections confirmed that piperine significantly reduced the extent of demyelination, inflammation, immune cell infiltration, microglia, and astrocyte activation. Gene expression analysis in lumbar spinal cord showed that piperine treatment decreased the level of pro-inflammatory cytokines (TNF-α, IL-1β) and iNOS and enhanced IL-10, Nrf2, HO-1, and MBP expressions. Piperine supplementation also enhanced the total antioxidant capacity (FRAP) and reduced the level of oxidative stress marker (MDA) in the CNS of EAE rats. Finally, we found that piperine has anti-apoptotic and neuroprotective effect in EAE through reducing caspase-3 (apoptosis marker) and enhancing BDNF and NeuN expressing cells. This study strongly indicates that piperine has a beneficial effect on the EAE progression and could be considered as a potential therapeutic target for MS treatment. Upcoming clinical trials will provide a deeper understanding of piperine's role for the treatment of the MS.