Fasudil-modified macrophages reduce inflammation and regulate the immune response in experimental autoimmune encephalomyelitis

Multiple sclerosis is characterized by demyelination and neuronal loss caused by inflammatory cell activation and infiltration into the central nervous system.Macrophage polarization plays an important role in the pathogenesis of experimental autoimmune encephalomyelitis,a traditional experimental model of multiple sclerosis.This study investigated the effect of Fasudil on macrophages and examined the therapeutic potential of Fasudil-modified macrophages in experimental autoimmune encephalomyelitis.We found that Fasudil induced the conversion of macrophages from the pro-inflammatory M1 type to the anti-inflammatory M2 type,as shown by reduced expression of inducible nitric oxide synthase/nitric oxide,interleukin-12,and CD16/32 and increased expression of arginase-1,interleukin-10,CD14,and CD206,which was linked to inhibition of Rho kinase activity,decreased expression of toll-like receptors,nuclear factor-κB,and components of the mitogen-activated protein kinase signaling pathway,and generation of the pro-inflammatory cytokines tumor necrosis factor-α,interleukin-1β,and interleukin-6.Crucially,Fasudil-modified macrophages effectively decreased the impact of experimental autoimmune encephalomyelitis,resulting in later onset of disease,lower symptom scores,less weight loss,and reduced demyelination compared with unmodified macrophages.In addition,Fasudil-modified macrophages decreased interleukin-17 expression on CD4^(+)T cells and CD16/32,inducible nitric oxide synthase,and interleukin-12 expression on F4/80^(+)macrophages,as well as increasing interleukin-10 expression on CD4^(+)T cells and arginase-1,CD206,and interleukin-10 expression on F4/80^(+)macrophages,which improved immune regulation and reduced inflammation.These findings suggest that Fasudil-modified macrophages may help treat experimental autoimmune encephalomyelitis by inducing M2 macrophage polarization and inhibiting the inflammatory response,thereby providing new insight into cell immunotherapy for multiple sclerosis.

Emodin attenuates inflammation and demyelination in experimental autoimmune encephalomyelitis

Emodin,a substance extracted from herbs such as rhubarb,has a protective effect on the central nervous system.However,the potential therapeutic effect of emodin in the context of multiple sclerosis remains unknown.In this study,a rat model of experimental autoimmune encephalomyelitis was established by immune induction to simulate multiple sclerosis,and the rats were intraperitoneally injected with emodin(20 mg/kg/d)from the day of immune induction until they were sacrificed.In this model,the nucleotide-binding domain-like receptor family pyrin domain containing 3(NLRP3)inflammasome and the microglia exacerbated neuroinflammation,playing an important role in the development of multiple sclerosis.In addition,silent information regulator of transcription 1(SIRT1)/peroxisome proliferator-activated receptor-alpha coactivator(PGC-1α)was found to inhibit activation of the NLRP3 inflammasome,and SIRT1 activation reduced disease severity in experimental autoimmune encephalomyelitis.Furthermore,treatment with emodin decreased body weight loss and neurobehavioral deficits,alleviated inflammatory cell infiltration and demyelination,reduced the expression of inflammatory cytokines,inhibited microglial aggregation and activation,decreased the levels of NLRP3 signaling pathway molecules,and increased the expression of SIRT1 and PGC-1α.These findings suggest that emodin improves the symptoms of experimental autoimmune encephalomyelitis,possibly through regulating the SIRT1/PGC-1α/NLRP3 signaling pathway and inhibiting microglial inflammation.These findings provide experimental evidence for treatment of multiple sclerosis with emodin,enlarging the scope of clinical application for emodin.

Role of nuclear factor κB in multiple sclerosis and experimental autoimmune encephalomyelitis

The transcription factor nuclear factor κB（NF-κB） plays major roles in inflammatory diseases through regulation of inflammation and cell viability.Multiple sclerosis（MS） is a chronic inflammatory demyelinating and neurodegenerative disease of the central nervous system（CNS）.It has been shown that NF-κB is activated in multiple cell types in the CNS of MS patients,including T cells,microglia/macrophages,astrocytes,oligodendrocytes,and neurons.Interestingly,data from animal model studies,particularly studies of experimental autoimmune encephalomyelitis,have suggested that NF-κB activation in these individual cell types has distinct effects on the development of MS.In this review,we will cover the current literature on NF-κB and the evidence for its role in the development of MS and its animal model experimental autoimmune encephalomyelitis.

MicroRNAs as disease progression biomarkers and therapeutic targets in experimental autoimmune encephalomyelitis model of multiple sclerosis

Multiple sclerosis is an autoimmune neurodegenerative disease of the central nervous system characterized by pronounced inflammatory infiltrates entering the brain,spinal cord and optic nerve leading to demyelination.Focal demyelination is associated with relapsing-remitting multiple sclerosis,while progressive forms of the disease show axonal degeneration and neuronal loss.The tests currently used in the clinical diagnosis and management of multiple sclerosis have limitations due to specificity and sensitivity.MicroRNAs(miRNAs)are dysregulated in many diseases and disorders including demyelinating and neuroinflammatory diseases.A review of recent studies with the experimental autoimmune encephalomyelitis animal model(mostly female mice 6–12 weeks of age)has confirmed miRNAs as biomarkers of experimental autoimmune encephalomyelitis disease and importantly at the pre-onset(asymptomatic)stage when assessed in blood plasma and urine exosomes,and spinal cord tissue.The expression of certain miRNAs was also dysregulated at the onset and peak of disease in blood plasma and urine exosomes,brain and spinal cord tissue,and at the post-peak(chronic)stage of experimental autoimmune encephalomyelitis disease in spinal cord tissue.Therapies using miRNA mimics or inhibitors were found to delay the induction and alleviate the severity of experimental autoimmune encephalomyelitis disease.Interestingly,experimental autoimmune encephalomyelitis disease severity was reduced by overexpression of miR-146a,miR-23b,miR-497,miR-26a,and miR-20b,or by suppression of miR-182,miR-181c,miR-223,miR-155,and miR-873.Further studies are warranted on determining more fully miRNA profiles in blood plasma and urine exosomes of experimental autoimmune encephalomyelitis animals since they could serve as biomarkers of asymptomatic multiple sclerosis and disease course.Additionally,studies should be performed with male mice of a similar age,and with aged male and female mice.

Sinomenine reduces iNOS expressionvia inhibiting the T-bet IFN-γ pathway in experimental autoimmune encephalomyelitis in rats

Sinomenine is a bioactive alkaloid isolated from the Chinese medicinal plant Sinomenium acutum. It is widely used as an immunosuppressive drug for treating rheumatic and arthritic diseases. In our previous studies, we found that sinomenine reduced cellular infiltration within the spinal cord and alleviated experimental autoimmune encephalomyelitis （EAE） in rats. In this study, we further investigated the mechanisms of sinomenine treatment in EAE rats. In EAE rats, treatment with sinomenine exerted an anti-inducible NO synthase （anti-iNOS） effect, which is related to the reductions of Thl cytokine interferon-y （IFN-7） and its transcription factor, T-bet, in spinal cords. Moreover, sinomenine treatment of splenocytes stimulated with anti-CD3 antibody and recombinant rat in- terleukin 12 reduced the expression of T-bet and IFN-y in vitro and also reduced the capability of supernatants of splenocyte culture to induce iNOS expression by primary astrocytes. However, sinomenine had no direct inhibito- ry effect on iNOS produced by astrocytes cultured with IFN-y and tumor necrosis factor α in vitro. In conclusion, the anti-iNOS effect of sinomenine on EAE is mediated via the suppression of T-bet/IFN-y pathway.

Effects of Yishendaluo decoction on axonal degeneration,inflammatory reaction,and neurological function in a mouse model of experimental autoimmune encephalomyelitis

BACKGROUND： Yishendaluo decoction reduces production of inflammatory mediators, relieves damage due to inflammatory reactions, and improves neural functions during experimental autoimmune encephalomyelitis. OBJECTIVE： To investigate the effects of Yishendaluo decoction on a mouse model of experimental autoimmune encephalomyelitis. DESIGN, TIME AND SETTING： The randomized, controlled, neuropathological, and molecular biological animal study was performed at the Key Laboratory of Chinese Internal Medicine, Ministry of Education, Dongzhimen Hospital of Beijing University of Chinese Medicine and Center for Neuroinformatics, General Hospital of Chinese PLA from 2005 to 2006. MATERIALS： Yishendaluo decoction pieces consisting of prepared rehmannia root, colla comus cervi, cape jasmine fruit, and grassleaf sweetflag rhizome were purchased from the Dongzhimen Hospital of Beijing University of Chinese Medicine. Rabbit anti-mouse β-amyloid precursor protein and p38 polyclonal antibody （Zhongshan Goldenbridge Biotechnology, China）, as well interferon-y and interleukin-4 ELISA kit （Boster, China）, were used in this study. METHODS： A total of 96 healthy, female, SJL/J mice, aged 8 12 weeks, were equally and randomly assigned to normal, model, hormone, and Chinese medicine groups. A total of 0.2 mL antigen preparation, supplemented with 150 μg PLP 139-151 and 400 μg H37RA, was subcutaneously injected into the upper abdomen of mice from the model, hormone, and Chinese medicine groups. Mouse models of experimental autoimmune encephalomyelitis were established by intravenous injection of 0.1 mL Bordetella pertussis solution containing 0.6 × 10^6 Bordetella pertussis at days 1 and 3. Mice from the model, Chinese medicine, and hormone groups were respectively subjected to 0.2 mL saline, 2 g/kg Yishendaluo decoction, and 0.078 mg/kg prednisone acetate, once daily for 14 consecutive days. Mice from the normal group were left intact. MAIN OUTCOME MEASURES： Pathological changes were observed using hematoxylin-eosin staining and Luxol fast blue staining. Expression of β-amyloid precursor protein and p38 protein was determined by immunohistochemistry. Levels of interferon-y and interleukin-4 were detected by ELISA. Behavioral changes were assessed in mice according to scores of neurological function. RESULTS： A few inflammatory cell infiltration, nerve fiber breakage and slight demyelination were detected in the central nervous system of mice from the Chinese medicine and hormone groups compared with the model group. Expression of β-amyloid precursor protein and p38 protein was significantly diminished in the central nervous system of mice from the Chinese medicine and hormone groups compared with the model group （P 〈 0.05 or P 〈 0.01）, and the decrease was greatest in the Chinese medicine group. The decrease in mouse weight was not significant, and neurological function scores were less in the Chinese medicine and hormone groups compared with the model group （P 〈 0.05 or P 〈 0.01）. Interferon-y levels were significantly reduced （P 〈 0.01）, and interleukin-4 levels were significantly increased （P 〈 0.01） in the brains of the Chinese medicine and hormone groups, compared with the model group. CONCLUSION： Yishendaluo decoction improved neurological function in mice with experimental autoimmune encephalomyelitis by downregulating β-amyloid precursor protein expression, resistingaxonal degeneration, and relieving inflammatory reaction. The anti-inflammatory mechanism was regulated by inhibition of the p38 mitogen-activated protein kinase signal pathway.

Amyloid precursor protein and growth-associated protein 43 expression in brain white matter and spinal cord tissues in a rat model of experimental autoimmune encephalomyelitis

Studies have demonstrated that amyloid precursor protein （APP） expression increases in multiple sclerosis tissues during acutely and chronically active stages. To determine the relationship between axonal injury and regeneration in multiple sclerosis, an animal model of experimental autoimmune encephalomyelitis was induced using different doses of myelin basic protein peptide. APP and growth-associated protein 43 （GAP-43）, which is considered a specific marker of neural regeneration, were assessed by western blot analysis. Expression of APP and GAP-43, as well as the correlation between these two proteins, in brain white matter and spinal cord tissues of experimental autoimmune encephalomyelitis rats at different pathological stages was analyzed. Results showed that APP and GAP-43 expression increased during the acute stage and decreased during remission, with a positive correlation between APP and GAP-43 expression in brain white matter and spinal cord tissues. These results suggest that APP and GAP-43 could provide nutritional and protective effects on damaged neurons.

Nogo receptor expression in microglia/macrophages during experimental autoimmune encephalomyelitis progression

Myelin-associated inhibitory factors within the central nervous system（CNS） are considered to be one of the main obstacles for axonal regeneration following disease or injury. The nogo receptor 1（NgR1） has been well documented to play a key role in limiting axonal regrowth in the injured and diseased mammalian CNS. However, the role of nogo receptor in immune cell activation during CNS inflammation is yet to be mechanistically elucidated. Microglia/macrophages are immune cells that are regarded as pathogenic contributors to inflammatory demyelinating lesions in multiple sclerosis（MS）. In this study, the animal model of MS, experimental autoimmune encephalomyelitis（EAE） was induced in ngr1^＋/＋ and ngr1^–/– female mice following injection with the myelin oligodendrocyte glycoprotein（MOG_（35–55）） peptide. A fatemap analysis of microglia/macrophages was performed throughout spinal cord sections of EAE-induced mice at clinical scores of 0, 1, 2 and 3, respectively（increasing locomotor disability） from both genotypes, using the CD11 b and Iba1 cell markers. Western immunoblotting using lysates from isolated spinal cord microglia/macrophages, along with immunohistochemistry and flow cytometric analysis, was performed to demonstrate the expression of nogo receptor and its two homologs during EAE progression. Myelin protein engulfment during EAE progression in ngr1^＋/＋ and ngr1^–/– mice was demonstrated by western immunblotting of lysates from isolated spinal cord microglia/macrophages, detecting levels of Nogo-A and MOG. The numbers of M1 and M2 microglia/macrophage phenotypes present in the spinal cords of EAE-induced ngr1^＋/＋ and ngr1^–/– mice, were assessed by flow cytometric analysis using CD38 and Erg-2 markers. A significant difference in microglia/macrophage numbers between ngr1^＋/＋ and ngr1^–/– mice was identified during the progression of the clinical symptoms of EAE, in the white versus gray matter regions of the spinal cord. This difference was unrelated to the expression of Ng R on these macrophage/microglial cells. We have identified that as EAE progresses, the phagocytic activity of microglia/macrophages with myelin debris, in ngr1^–/– mice, was enhanced. Moreover, we show a modulation from a predominant M1-pathogenic to the M2-neurotrophic cell phenotype in the ngr1^–/– mice during EAE progression. These findings suggest that CNS-specific macrophages and microglia of ngr1^–/– mice may exhibit an enhanced capacity to clear inhibitory molecules that are sequestered in inflammatory lesions.

Zuogui pills for myelinolysis in a rat model of experimental autoimmune encephalomyelitis

Zuogui pills have been shown to attenuate the inflammatory reaction in a rat model of experimental autoimmune encephalomyelitis （EAE）. The present study attempted to investigate the pathology underlying the influence of Zuogui pills on myelinolysis in EAE rats. Hematoxylin-eosin and Luxol fast blue staining showed that the myelinolysis foci in the cerebrum, cerebellum, brain stem, and the spinal cord of EAE rats were significantly decreased, along with serum myelin basic protein content following treatment with Zuogui pills.

High doses of α-galactosylceramide potentiate experimental autoimmune encephalomyelitis by directly enhancing Th17 response

α-Galactosylceramide （u-GC） is widely known to activate invariant natural killer T （iNKT） cells to suppress my- elin antigen-specific Thl responses, protecting susceptible mice against experimental antoimmune encephalomyelitis 0EAE）. Here, we demonstrate an unexpected finding that high doses of α-GC exacerbated, rather than ameliorated, EAE. Similar results were observed when MOG35.ss-specific T cells treated with high-dose α-GC were transferred into naive syngeneic recipient mice. Further study showed that high doses of a-GC directly enhance the Thl7 and Thl re- sponse by activation of CD4＋CD44＋ memory T cells through phosphorylation of STAT3 and activation of NF-kB. Un- like the activation of iNKT cells by low doses of a-GC, high doses of a-GC directly interacted with CDld expressed on T ceils and activated Thl7 and Thl cells. Furthermore, antigen-presenting cells （APCs） predominantly express CDldl, whereas the majority of CD4~ T cells express CDld2. Knockdown of CDldl or CDld2 gene expression by RNAi interfered with the activation of iNKT or Thl7/Thl cells, respectively. Therefore, α-GC treatment could im- prove or worsen EAE by engaging either APCs or Thl7/Thl cells depending on the dose used.

Nogo-A and Nogo-A receptor expression in periventricular white matter of experimental autoimmune encephalomyelitis rats

BACKGROUND：Previous studies have focused on the correlation between Nogo-A expression and multiple sclerosis or between Nogo-A receptor （NgR） expression and multiple sclerosis in the central nervous system. Expression patterns of Nogo-A and NgR remain poorly understood in rat models of experimental autoimmune encephalomyelitis （EAE）.OBJECTIVE：To observe dynamic changes in Nogo-A and NgR protein expression, and to verify the correlation between Nogo-A and NgR protein, as well as expression patterns at various time points, in periventricular tissue of EAE rats.DESIGN, TIME AND SETrlNG：A neuroimmunological, randomized, controlled experiment was performed at the Clinical Institute of Hunan People＇s Hospital of China from September to November 2008.MATERIALS：Immunohistochemistry （streptavidin-biotin-peroxidase complex method） kit was purchased from Boster, China.METHODS：A total of 60 female, Wistar rats, aged 6-8 weeks, ware randomly assigned to EAE and control groups （n = 30, respectively）. Guinea pig spinal cord homogenate, self-made complete Freund＇s adjuvant （0.2 mL/100 g）, and pertussis vaccine （0.2 mL） were subcutaneously injected into the hindlimb foot pad of rats from the EAE group to create rat models of EAE. Complete Freund＇s adjuvant （0.2 mL） was infused into rats from the control group.MAIN OUTCOME MEASURES：Nogo-A and NgR protein expression was determined in periventricular white matter using immunohistochemical methods. Neurological scores ware determined in all rats.RESULTS：Rats from the EAE group developed acute-onset EAE following immunization. The pathogenetic symptoms reached a peak on day 15, and neurological scores ware also greatest at this time point. Neurological scores decreased with recovery of the illness. Nogo-A was shown to be expressed in neuronal cells and oligodendrocytes, and expression increased 11 days after immunization （P 〈 0.01）, decreased by day 13 （P 〈 0.01）, and then increased again by day 15. Nogo-A expression remained greater in the EAE group compared with the control group at day 30 （P 〈 0.01）. In the EAE group, NgR protein was primarily expressed on the surface of neuronal bodies and axons. NgR expression increased 13-18 days after immunization （P 〈 0.01 or P 〈 0.05）.CONCLUSION：Nogo-A and NgR protein expression altered with disease course in periventdcular white matter of EAE rats. Results suggested that Nogo-A and NgR were involved in EAE occurrence.

Effects of Yishendaluo decoction on blood-brain barrier integrity in mice with experimental autoimmune encephalomyelitis

This study investigated the effects of Yishendaluo decoction on the loss of blood-brain barrier integrity in mice exhibiting experimental autoimmune encephalomyelitis.To this end,we used real-time fluorescent quantitative PCR to measure the levels of mRNAs specific to the T cell markers CD4 and CD8,and the monocyte marker CD11b.In addition,we used Evans blue dye extravasation in the spinal cord and brain tissues to assess blood-brain barrier permeability.The results indicated that an increase in blood-brain barrier permeability was associated with an increase in CD4,CD8 and CD11b mRNA expression in experimental autoimmune encephalomyelitis mice.Yishendaluo decoction administration significantly reversed inflammatory cell accumulation in cerebral tissues of experimental autoimmune encephalomyelitis mice.

Axonal damage in myelin oligodendrocyte glycoprotein peptide-induced experimental autoimmune encephalomyelitis in a C57BL/6 mouse model may be not secondary to inflammatory demyelination

The present study established a chronic experimental autoimmune encephalomyelitis model in C57BL/6 mice induced by myelin oligodendrocyte glycoprotein peptides and complete Freund＇s adjuvant. Onset latency was 12 days, with an incidence rate of 100%. Neuropathological characteristics included perivascular inflammatory cell infiltration, demyelination, neuronal degeneration, and axonal damage within cerebral and myelic white matter. Electron microscopy revealed swollen mitochondria, complete organ disappearance, and fused or broken myelin sheath structure, which were accompanied by myelin sheath reconstruction. Moreover, axonal damage was not consistent with demyelination distribution, and severity of axonal damage did not correlate with demyelination. Results suggested that axonal damage in an experimental autoimmune encephalomyelitis model is not secondary to inflammatory demyelination.

Ameliorative effects of human adipose tissue-derived mesenchymal stem cells on myelin basic protein-induced experimental autoimmune encephalomyelitis in Lewis rats

Mesenchymal stem cells have been previously shown to exert an immunomodulatory function. The present study sought to investigate the effects of multipotential human adipose tissue-derived mesenchymal stem cells （hAdMSCs） on disease progression and cytokine expression in Lewis rats with experimental autoimmune encephalomyelitis （EAE） induced by myelin basic protein. The duration of EAE paralysis in the group treated on day 7 posfimmunization with 5 × 10^6 hAdMSCs was significantly reduced compared with the vehicle-treated controls and the 1 x 106 hAdMSC- treated group. The duration of EAE paralysis in the groups treated with 5 × 10^6 hAdMSCs on both day 1 and day 7 postimmunization was significantly reduced compared with the vehicle-treated controls and the groups treated with 5 × 10^6 hAdMSCs on both day 7 and day 10 postimmunization. The mRNA expression of interleukin-10 and indoleamine 2, 3-dioxygenase was significantly decreased in the hAdMSC-treated group compared with the vehicle-treated group. These findings suggest that the ameliorative effects of hAdMSCs on EAE symptoms operate in a dose- and time-dependent manner and can be mediated in part by the ample production of anti-inflammatory cytokines.

Matrine ameliorates experimental autoimmune encephalomyelitis by regulating the differentiation of encephalitogenic Th1/Th17 and Th2/regulatory T cells

OBJECTIVE Experimental autoimmune encephalomyelitis(EAE),the classical animal model for multiple sclerosis(MS)is triggered by an impaired balance of T helper(Th)cells and regulatory T(Tregs)cells.Matrine(MAT),a quinolizidine alkaloid derived from the herb Radix Sophorae Flave,has been shown to ameliorate the clinical signs,inflammatory infiltration,demyelination in acute EAE rats.However,whether MAT protect from EAE by adjusting Th and Treg cells response in specific-cellular and molecular level is unknown.METHODS Herein,MAT was tested for its effects on Th1,Th2,Th17 and Treg cells in the spinal cord of EAE mice and splenocyte-extracted from EAE mice with MOG35-55-restimulated,respectively.RESULTS Our findings revealed that MAT significantly inhibit the proliferation of splenocyte,and remarkably down-regulate the differentiation of Th1/Th17 cells with decreased expressions of CD4+IFN-γ+cells and CD4+IL-17+cells in vivo and IL-17,IFN-γ,ROR-γt,T-bet in vitro,meanwhile it dramatically up-regulate the Th2/Treg cells response associated with increased levels of CD4+TGF-β+1cells and CD4+IL-10+cells in vivo and IL-4,IL-10,TGF-β1,Foxp3 and GATA3in vitro.CONCLUSION Considering the effective therapeutic effects of MAT on EAE,it′s worth to find its new values on other autoimmune diseases.

Editor's Choice——Experimental autoimmune encephalomyelitis and neuroregeneration

An experimental autolmmune encephalomyelitis model can be used to mimic pathological changes of multiple sclerosis from different angles. During the acute phase of experimental autolmmune encephalomyelitis, CD4＋ T-cells in the central nervous system infiltrate, proliferate, release large amounts of pro-inflammatory cytokines, and activate the inflammatory cascade, which ultimately leads to

Dynamic interplay of T helpercell subsets in experimental autoimmune encephalomyelitis

AIM： To investigate the temporal onset and dynamic interplay of CD4^＋ T helper cell subsets in experimental autoimmune encephalomyelitis （EAE）.METHODS： EAE was induced in C57BL/6 mice by im-munization with myelin oligodendrocyte glycoprotein peptide p35-55. The clinical signs were scored and the tissue samples and immune cells isolated for analysis at different phases of EAE. The expression levels of inflammatory cytokines and related transcription fac-tors were detected by quantitative reverse transcription polymerase chain reaction （PCR） and enzyme linked immunosorbant assay （ELISA）. The percentages of Th1, Th17, Th2, Treg and memory T cell subsets in EAE were analyzed by immunostaining and fow cytometry. The data were analyzed by statistical techniques.RESULTS： Quantitative real-time PCR analysis showed that EAE mice express elevated levels of Th1 [interferon gamma （ IFNγ ）, interleukin （ IL ） -12p40 ], Th17 [ IL-17 , related orphan receptor gamma （RORγ ）, IL-12p40] and Treg [ Foxp3, Epstein-Barr virus induced gene 3 （EBI3）, IL-10] genes in the central nervous system at the peak of the disease. Whereas, the expression of Th1 （ IFNγ , T-bet, IL-12p35, IL-12p40 ）, Th17 （RORγ, IL-12p40 ）, Th2 （ IL-4） and Treg （ Foxp3, EBI3） response genes was reduced in the spleen during pre-disease but gradually recovered at the later phases of EAE. ELISA and fow cytometry analyses showed an increase in Th17 re-sponse in the periphery, while Th1 response remained unchanged at the peak of disease. The mRNA levels of IFNγ, IL-17 and IL-12p40 in the brain were increased by 23 （P 〈 0.001）, 9 （P 〈 0.05） and 14 （P 〈 0.01） fold, respectively, on day 21 of EAE. Conversely, the mRNA expression of IL-10 was increased by 2 fold （P 〈 0.05） in the spleen on day 21. CD4^＋CD25^＋Foxp3＋Treg response was reduced at pre-disease but recovered to na？ve levels by disease onset. The percentage of CD25 Foxp3 regulatory T cells decreased from 7.7% in the na？ve to 3.2% （P 〈 0.05） on day 7 of EAE, which then increased to 8.4% by day 28. Moreover, the CD4＋CD127＋CD44high memory T cell response was increased during the onset and recovery phases of EAE. The memory and effector cells showed an in-verse relationship in EAE, where the memory T cells increased from 12.3% in nave to 20% by day 21, and the effector cells decreased from 32% in na？ve to 21% （P 〈 0.01） by day 21. The wild type C57BL/6 mice with EAE showed elevated levels of effector-memory T cells （TEM） with concomitant reduction in central-memory T cells （TCM）, but the EAE-resistant IL-7R defcient mice showed elevated TCM with no effect on TEM cells in EAE.CONCLUSION： Our fndings highlight the temporal on-set and dynamic interplay of effector, memory and regu-latory CD4^＋ T cell subsets and its signifcance to clinical outcome in EAE and other autoimmune diseases.

EAE （Experimental Autoimmune Encephalomyelitis）, Corticotropin-Releasing Factor and the Blood Brain Barrier

EAE （experimental autoimmune encephalomyelitis） is an established, inducible animal model employed in the study of MS （multiple sclerosis） characterized by inflammation, BBB （blood brain barrier） malfunction, demyelination and neuronal disruption. CRF （corticotropin releasing factor） is a neuropeptide critically associated with immune function, BBB permeability, and the hypothalamic-pituitary-adrenal axis. Potential CRF targets in the brain include astrocytes, as well as endothelial cells of cerebral microvessels, since they have been reported to express CRFR （CRF receptors）. Further, both of these cell types function critically in regulating BBB permeability. CRF-BP （CRF binding protein） is also expressed in both neurons and glial cells. Changes in the cortical CRF system could be a contributing factor to the BBB disruption associated with MS/EAE and has been suggested to play a protective role against cytokine-induced inflammation. The current study assessed alterations associated with the C57BL/6 mouse model of EAE in the cortical CRF system and correlated these events with changes to the microvascular unit. Immunohistochemical confocal microscopy was used to analyze the distribution of CRF, CRF-BP, and CRFR in the mouse cerebral cortex. The authors observed a reduction in detectable CRF immunofluorescence in the EAE motor cortex, an increase in CRFBP immunoreactivity in EAE astrocytes and a concurrent reduction in astrocytic CRFR immunofluorescence. Staining techniques were used to visualize astrocytes/microvessels to document alterations in BBB integrity. Changes in the CRF system were associated with a modification of the blood brain barrier as manifested by a poorly defined astrocytic barrier in EAE microvessels. Evidence suggests that manipulation of CRF signaling pathways offers an intriguing target for interventional therapies designed to modify BBB permeability that may be beneficial for treating disease states such as MS.

Early Growth Response Gene-1 Deficiency Interrupts TGFβ1 Signaling Activation and Aggravates Neurodegeneration in Experimental Autoimmune Encephalomyelitis Mice

Early growth response protein 1(Egr-1)triggers the transcription of many genes involved in cell growth,differentiation,synaptic plasticity,and neurogenesis.However,its mechanism in neuronal survival and degeneration is still poorly understood.This study demonstrated that Egr-1 was down-regulated at mRNA and protein levels in the central nervous system(CNS)of experimental autoimmune encephalomyelitis(EAE)mice.Egr-1 knockout exacerbated EAE progression in mice,as shown by increased disease severity and incidence;it also aggravated neuronal apoptosis,which was associated with weakened activation of the BDNF/TGFβ1/MAPK/Akt signaling pathways in the CNS of EAE mice.Consistently,Egr-1 siRNA promoted apoptosis but mitigated the activation of BDNF/TGFβ1/MAPK/Akt signaling in SH-SY5Y cells.Our results revealed that Egr-1 is a crucial regulator of neuronal survival in EAE by regulating TGFβ1-mediated signaling activation,implicating the important role of Egr-1 in the pathogenesis of multiple sclerosis as a potential novel therapy target.

Grape Seed Extract Attenuates Demyelination in Experimental Autoimmune Encephalomyelitis Mice by Inhibiting Inflammatory Response of Immune Cells

Objective: To examine the anti-inflammatory effect of grape seed extract(GSE) in animal and cellular models and explore its mechanism of action. Methods: This study determined the inhibitory effect of GSE on macrophage inflammation and Th1 and Th17 polarization in vitro. Based on the in vitro results, the effects and mechanisms of GSE on multiple sclerosis(MS)-experimental autoimmune encephalomyelitis(EAE) mice model were further explored. The C57BL/6 mice were intragastrically administered with 50 mg/kg of GSE once a day from the 3rd day to the 27th day after immunization. The activation of microglia, the polarization of Th1 and Th17and the inflammatory factors such as tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), IL-6, IL-12, IL-17and interferon-γ(IFN-γ) secreted by them were detected in vitro and in vivo by flow cytometry, enzyme linked immunosorbent assay(ELISA), immunofluorescence staining and Western blot, respectively. Results: GSE reduced the secretion of TNF-α, IL-1β and IL-6 in bone marrow-derived macrophages stimulated by lipopolysaccharide(P<0.01), inhibited the secretion of TNF-α, IL-1β, IL-6, IL-12, IL-17 and IFN-γ in spleen cells of EAE mice immunized for 9 days(P<0.05 or P<0.01), and reduced the differentiation of Th1 and Th17 mediated by CD3 and CD28 factors(P<0.01). GSE significantly improved the clinical symptoms of EAE mice, and inhibited spinal cord demyelination and inflammatory cell infiltration. Peripherally, GSE downregulated the expression of toll-like-receptor 4(TLR4) and Rho-associated kinase(ROCKⅡ, P<0.05 or P<0.01), and inhibited the secretion of inflammatory factors(P<0.01 or P<0.05). In the central nervous system, GSE inhibited the infiltration of CD45+CD11b+and CD45+CD4+cells, and weakened the differentiation of Th1 and Th17(P<0.05). Moreover, it reduced the secretion of inflammatory factors(P<0.01), and prevented the activation of microglia(P<0.05). Conclusion: GSE had a beneficial effect on the pathogenesis and progression of EAE by inhibiting inflammatory response as a potential drug and strategy for the treatment of MS.