Multiple sclerosis (MS) is a neuroinflammatory demyelinating disease, mediated by pathogenic T helper 17 (Th17) cells. However, the therapeutic effect is accompanied by the fluctuation of the proportion and function of Th17 cells, which prompted us to find the key regulator of Th17 differentiation in MS. Here, we demonstrated that the triggering receptor expressed on myeloid cells 2 (TREM-2), a modulator of pattern recognition receptors on innate immune cells, was highly expressed on pathogenic CD4-positive T lymphocyte (CD4⁺ T) cells in both patients with MS and experimental autoimmune encephalomyelitis (EAE) mouse models. Conditional knockout of Trem-2 in CD4⁺ T cells significantly alleviated the disease activity and reduced Th17 cell infiltration, activation, differentiation, and inflammatory cytokine production and secretion in EAE mice. Furthermore, with Trem-2 knockout in vivo experiments and in vitro inhibitor assays, the TREM-2/zeta-chain associated protein kinase 70 (ZAP70)/signal transducer and activator of transcription 3 (STAT3) signal axis was essential for Th17 activation and differentiation in EAE progression. In conclusion, TREM-2 is a key regulator of pathogenic Th17 in EAE mice, and this sheds new light on the potential of this therapeutic target for MS.
Animals ; Humans ; Mice ; CD4-Positive T-Lymphocytes/pathology* ; Cell Differentiation ; Encephalomyelitis, Autoimmune, Experimental/metabolism* ; Mice, Inbred C57BL ; Multiple Sclerosis ; Th1 Cells/pathology*

The primary chemical components of Astragalus membranaceus include polysaccharides, saponins, flavonoids, and amino acids. Recent studies have shown that Astragalus membranaceus has multiple functions, including improving immune function and exerting antioxidative, anti-radiation, anti-tumor, antibacterial, antiviral, and hormone-like effects. Astragalus membranaceus and its extracts are widely used in clinical practice because they have obvious therapeutic effects against various autoimmune diseases and relatively less adverse reaction. Multiple sclerosis (MS) is an autoimmune disease of central nervous system (CNS), which mainly caused by immune disorder that leads to inflammatory demyelination, inflammatory cell infiltration, and axonal degeneration in the CNS. In this review, the authors analyzed the clinical manifestations of MS and experimental autoimmune encephalomyelitis (EAE) and focused on the efficacy of Astragalus membranaceus and its chemical components in the treatment of MS/EAE.
Animals ; Humans ; Astragalus propinquus/chemistry* ; Multiple Sclerosis/drug therapy* ; Encephalomyelitis, Autoimmune, Experimental/metabolism* ; Drugs, Chinese Herbal/chemistry* ; Polysaccharides

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 Th17 and the inflammatory factors such as tumor necrosis factor- α (TNF- α), interleukin-1 β (IL-1 β), IL-6, IL-12, IL-17 and 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-1 β and IL-6 in bone marrow-derived macrophages stimulated by lipopolysaccharide (P<0.01), inhibited the secretion of TNF-α, IL-1 β, 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.
Mice ; Animals ; Encephalomyelitis, Autoimmune, Experimental/pathology* ; Grape Seed Extract/therapeutic use* ; Interleukin-17 ; Interleukin-1beta ; Tumor Necrosis Factor-alpha/metabolism* ; Interleukin-6/metabolism* ; Th1 Cells ; Mice, Inbred C57BL ; Interferon-gamma/therapeutic use* ; Th17 Cells/metabolism* ; Interleukin-12/therapeutic use* ; Cytokines/metabolism*

Multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE), a pathologically similar disease used to model MS in rodents, are typical CD4+ T cell-dominated autoimmune diseases. CD4+ interleukin (IL)17+ T cells (Th17 cells) have been well studied and have shown that they play a critical role in the pathogenesis of MS/EAE. However, studies have suggested that CD8+IL17+ T cells (Tc17 cells) have a similar phenotype and cytokine and transcription factor profiles to those of Th17 cells and have been found to be crucial in the pathogenesis of autoimmune diseases, including MS/EAE, psoriasis, type I diabetes, rheumatoid arthritis, and systemic lupus erythematosus. However, the evidence for this is indirect and insufficient. Therefore, we searched for related publications and attempted to summarize the current knowledge on the role of Tc17 cells in the pathogenesis of MS/EAE, as well as in the pathogenesis of other autoimmune diseases, and to find out whether Tc17 cells or Th17 cells play a more critical role in autoimmune disease, especially in MS and EAE pathogenesis, or whether the interaction between these two cell types plays a critical role in the development of the disease.
Animals ; Mice ; Encephalomyelitis, Autoimmune, Experimental ; Th17 Cells ; CD8-Positive T-Lymphocytes/metabolism* ; CD4-Positive T-Lymphocytes/metabolism* ; Multiple Sclerosis/metabolism* ; Mice, Inbred C57BL

High mobility group box 1 (HMGB1) has been reported to play an important role in experimental autoimmune encephalomyelitis (EAE). Astrocytes are important components of neurovascular units and tightly appose the endothelial cells of microvessels by their perivascular endfeet and directly regulate the functions of the blood-brain barrier. Astrocytes express more HMGB1 during EAE while the exact roles of astrocytic HMGB1 in EAE have not been well elucidated. Here, using conditional-knockout mice, we found that astrocytic HMGB1 depletion decreased morbidity, delayed the onset time, and reduced the disease score and demyelination of EAE. Meanwhile, there were fewer immune cells, especially pathogenic T cells infiltration in the central nervous system of astrocytic HMGB1 conditional-knockout EAE mice, accompanied by up-regulated expression of the tight-junction protein Claudin5 and down-regulated expression of the cell adhesion molecules ICAM1 and VCAM1 in vivo. In vitro, HMGB1 released from astrocytes decreased Claudin5 while increased ICAM1 and VCAM1 expressed by brain microvascular endothelial cells (BMECs) through TLR4 or RAGE. Taken together, our results demonstrate that HMGB1 derived from astrocytes aggravates EAE by directly influencing the immune cell infiltration-associated functions of BMECs.
Mice ; Animals ; Encephalomyelitis, Autoimmune, Experimental/metabolism* ; Astrocytes/metabolism* ; HMGB1 Protein/metabolism* ; Endothelial Cells/metabolism* ; Mice, Inbred C57BL ; Mice, Knockout ; Blood-Brain Barrier/metabolism*

OBJECTIVE: To evaluate the efficacy of rapmycin for treatment of experimental autoimmune encephalomyelitis (EAE) in mice and explore the underlying mechanism. METHODS: An EAE model was established in C57BL/6 mice. After immunization, the mice were divided into model group and rapamycin groups treated daily with low-dose (0.3 mg/kg) or high-dose (1 mg/kg) rapamycin. The clinical scores of the mice were observed using Knoz score, the infiltration of IL-17 cells in the central nervous system (CNS) was determined using immunohistochemistry; the differentiation of peripheral Treg cells was analyzed using flow cytometry, and the changes in the levels of cytokines were detected with ELISA; the changes in the expressions of p-Smad2 and p- smad3 were investigated using Western blotting. RESULTS: High-dose rapamycin significantly improved the neurological deficits scores of EAE mice. In high-dose rapamycin group, the scores in the onset stage, peak stage and remission stage were 0.14±0.38, 0.43±1.13 and 0.14±0.37, respectively, as compared with 1.14±0.69, 2.14±1.06 and 2.2±0.75 in the model group. The infiltration of inflammatory IL-17 cells was significantly lower in high-dose rapamycin group than in the model group (43±1.83 153.5±7.02). High-dose rapamycin obviously inhibited the production of IL-12, IFN-γ, IL-17 and IL-23 and induced the anti-inflammatory cytokines IL-10 and TGF-β. The percentage of Treg in CD4+ T cells was significantly higher in high- dose rapamycin group than in the model group (10.17 ± 0.68 3.52 ± 0.32). In the experiment, combined treatments of the lymphocytes isolated from the mice with rapamycin and TGF-β induced a significant increase in the number of Treg cells (13.66±1.89) compared with the treatment with rapamycin (6.23±0.80) or TGF-β (4.87±0.85) alone. Rapamycin also obviously up-regulated the expression of p-Smad2 and p-Smad3 in the lymphocytes. CONCLUSIONS Rapamycin can promote the differentiation of Treg cells by up-regulating the expression of p-Smad2 and p-smad3 to improve neurological deficits in mice with EAE.
Animals ; Anti-Inflammatory Agents ; administration & dosage ; therapeutic use ; Cell Differentiation ; drug effects ; Encephalomyelitis, Autoimmune, Experimental ; drug therapy ; metabolism ; Interferon-gamma ; metabolism ; Interleukins ; metabolism ; Lymphocytes ; cytology ; Mice ; Mice, Inbred C57BL ; Sirolimus ; administration & dosage ; therapeutic use ; Smad Proteins ; metabolism ; T-Lymphocytes, Regulatory ; cytology ; drug effects ; Transforming Growth Factor beta ; metabolism ; Up-Regulation

The obstacle to successful remyelination in demyelinating diseases, such as multiple sclerosis, mainly lies in the inability of oligodendrocyte precursor cells (OPCs) to differentiate, since OPCs and oligodendrocyte-lineage cells that are unable to fully differentiate are found in the areas of demyelination. Thus, promoting the differentiation of OPCs is vital for the treatment of demyelinating diseases. Shikimic acid (SA) is mainly derived from star anise, and is reported to have anti-influenza, anti-oxidation, and anti-tumor effects. In the present study, we found that SA significantly promoted the differentiation of cultured rat OPCs without affecting their proliferation and apoptosis. In mice, SA exerted therapeutic effects on experimental autoimmune encephalomyelitis (EAE), such as alleviating clinical EAE scores, inhibiting inflammation, and reducing demyelination in the CNS. SA also promoted the differentiation of OPCs as well as their remyelination after lysolecithin-induced demyelination. Furthermore, we showed that the promotion effect of SA on OPC differentiation was associated with the up-regulation of phosphorylated mTOR. Taken together, our results demonstrated that SA could act as a potential drug candidate for the treatment of demyelinating diseases.
Animals ; Apoptosis ; drug effects ; Cell Differentiation ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Demyelinating Diseases ; prevention & control ; Encephalitis ; prevention & control ; Encephalomyelitis, Autoimmune, Experimental ; prevention & control ; Female ; Mice, Inbred C57BL ; Myelin Basic Protein ; metabolism ; Neuroprotective Agents ; administration & dosage ; Oligodendrocyte Precursor Cells ; drug effects ; metabolism ; Rats ; Remyelination ; drug effects ; Shikimic Acid ; administration & dosage ; TOR Serine-Threonine Kinases ; metabolism

BACKGROUNDTh9 cells are a newly discovered CD4+ T helper cell subtype, characterized by high interleukin (IL)-9 secretion. Growing evidences suggest that Th9 cells are involved in the pathogenic mechanism of multiple sclerosis (MS). Mast cells are multifunctional innate immune cells, which are perhaps best known for their role as dominant effector cells in allergies and asthma. Several lines of evidence point to an important role for mast cells in MS and its animal models. Simultaneously, there is dynamic "cross-talk" between Th9 and mast cells. The aim of the present study was to examine the IL-9-mast cell axis in experimental autoimmune encephalomyelitis (EAE) and determine its interaction after neutralizing anti-IL-9 antibody treatment.

METHODSFemale C57BL/6 mice were randomly divided into three groups (n = 5 in each group): mice with myelin oligodendrocyte glycoprotein (MOG)-induced EAE (EAE group), EAE mice treated with anti-IL-9 antibody (anti-IL-9 Abs group), and EAE mice treated with IgG isotype control (IgG group). EAE clinical score was evaluated. Mast cells from central nervous system (CNS) were detected by flow cytometry. The production of chemokine recruiting mast cells in the CNS was explored by reverse transcription-polymerase chain reaction (RT-PCR). In mice with MOG-induced EAE, the expression of IL-9 receptor (IL-9R) complexes in CNS and spleen mast cells was also explored by RT-PCR, and then was repeating validated by immunocytochemistry. In vitro, spleen cells from EAE mice were cultured with anti-IL-9 antibody, and quantity of mast cells was counted by flow cytometry after co-culture.

RESULTSCompared with IgG group, IL-9 blockade delayed clinical disease onset and ameliorated EAE severity (t = -2.217, P = 0.031), accompany with mast cells infiltration decreases (day 5: t = -8.005, P < 0.001; day 15: t = -11.857, P < 0.001; day 20: t = -5.243, P = 0.001) in anti-IL-9 Abs group. The messenger RNA expressions of C-C motif chemokine ligand 5 (t = -5.932, P = 0.003) and vascular cell adhesion molecule-1 (t = -4.029, P = 0.004) were significantly decreased after IL-9 neutralization in anti-IL-9 Abs group, compared with IgG group. In MOG-induced EAE, the IL-9R complexes were expressed in CNS and spleen mast cells. In vitro, splenocytes cultured with anti-IL-9 antibody showed significantly lower levels of mast cells in a dose-dependent manner, compared with splenocytes cultured with anti-mouse IgG (5 μg/ml: t = -0.894, P = 0.397; 10 μg/ml: t = -3.348, P = 0.019; 20 μg/ml: t = -7.639, P < 0.001).

CONCLUSIONSThis study revealed that IL-9 neutralization reduced mast cell infiltration in CNS and ameliorated EAE, which might be relate to the interaction between IL-9 and mast cells.

Animals ; Antibodies ; therapeutic use ; Central Nervous System ; metabolism ; Encephalomyelitis, Autoimmune, Experimental ; drug therapy ; metabolism ; Female ; Immunohistochemistry ; Interleukin-9 ; antagonists & inhibitors ; immunology ; metabolism ; Mast Cells ; metabolism ; Mice ; Mice, Inbred C57BL ; RNA, Messenger ; genetics ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVETo study the effects of Bushen Yisui Capsule (, BSYSC) on the oligodendrocyte lineage genes (Olig) 1 and Olig2 in C57BL/6 mice with experimental autoimmune encephalomyelitis (EAE) in order to explore the remyelination effect of BSYSC.

METHODSThe mice were randomly divided into normal control (NC), EAE model (EAE-M), prednisone acetate (PA, 6 mg/kg), BSYSC high-dose (3.02 g/kg) and BSYSC low-dose (1.51 g/kg) groups. The mice were induced by immunization with myelin oligodendrocyte glycoprotein (MOG) 35-55. The neurological function scores were assessed once daily. The pathological changes in mice brains were observed with hematoxylin-eosin (HE) staining and transmission electron microscope (TEM). The protein expressions of myelin basic protein (MBP), Olig1 and Olig2 in brains were measured by immunohistochemistry. The mRNA expressions of Olig1 and Olig 2 was also determined by quantitative real-time polymerase chain reaction.

RESULTSCompared with the EAE-M mice, (1) the neurological function scores were significantly decreased in BSYSC-treated mice on days 22 to 40 (P<0.01); (2) the inflammatory cells and demyelination in brains were reduced in BSYSC-treated EAE mice; (3) the protein expression of MBP was markedly increased in BSYSC-treated groups on day 18 and 40 respectively (P<0.05 or P<0.01); (4) the protein expression of Olig1 was increased in BSYSC (3.02 g/kg)-treated EAE mice on day 40 (P<0.01). Protein and mRNA expression of Olig2 was increased in BSYSC-treated EAE mice on day 18 and 40 (P<0.01).

CONCLUSIONThe effects of BSYSC on reducing demyelination and promoting remyelination might be associated with the increase of Olig1 and Olig2.

Animals ; Basic Helix-Loop-Helix Transcription Factors ; genetics ; metabolism ; Brain ; drug effects ; pathology ; ultrastructure ; Bromodeoxyuridine ; metabolism ; Capsules ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Encephalomyelitis, Autoimmune, Experimental ; drug therapy ; genetics ; pathology ; physiopathology ; Female ; Fluorescent Antibody Technique ; Mice, Inbred C57BL ; Myelin-Oligodendrocyte Glycoprotein ; metabolism ; Nerve Tissue Proteins ; genetics ; metabolism ; Oligodendrocyte Transcription Factor 2 ; RNA, Messenger ; genetics ; metabolism

OBJECTIVETo study the effects of Zuogui Pill (, ZGP) and Yougui Pill (, YGP) on the expressions of brain-derived neurotrophic factor (BDNF) and cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) signaling of axonal regeneration in the Lewis rats with experimental autoimmune encephalomyelitis (EAE), in order to explore the possible mechanism of ZGP and YGP on promoting axonal regeneration.

METHODSThe rats were randomly divided into normal control (NC), model (MO), prednisone acetate (PA), ZGP and YGP groups. The EAE model of rat was established by injecting antigen containing myelin basic protein (MBP)68-86. The brain and spinal cord were harvested on the 14th and 28th day post-immunization (PI), the protein and mRNA expression of BDNF and PKA in the brain and spinal cord of rats were detected by Western blot analysis and real-time quantitative polymerase chain reaction (PCR), and the cAMP levels were detected by using enzyme-immunoassay method.

RESULTS(1) On the 28th day PI, the mRNA expression of BDNF in brain white matter and spinal cord of rats in ZGP and YGP groups were up-regulated, especially in YGP group (P<0.05 or P<0.01). (2) On the 14th day PI, the cAMP levels in brain white matters significantly increased in PA and YGP groups compared with MO group (P<0.05 or P<0.01), and the cAMP level in YGP group was higher than that in ZGP group (P<0.05). The cAMP level in spinal cord also significantly increased in YGP group compared with MO, PA and ZGP groups, respectively (P<0.01). (3) On the 14th day PI, the PKA expression in spinal cord of rats in ZGP group was significantly decreased compared with MO and YGP groups, respectively (P<0.05). (4) On the 28th day PI, there was a positive correlation between cAMP and PKA expression in the brain white matter of YGP rats.

CONCLUSIONSThe results suggest that ZGP and YGP may promote axonal regeneration by modulating cAMP/PKA signal transduction pathway, but the targets of molecular mechanism of ZGP may be different from those of YGP.

Animals ; Axons ; drug effects ; pathology ; Brain ; drug effects ; metabolism ; pathology ; Brain-Derived Neurotrophic Factor ; genetics ; metabolism ; Cyclic AMP ; metabolism ; Cyclic AMP-Dependent Protein Kinases ; genetics ; metabolism ; Disease Models, Animal ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Encephalomyelitis, Autoimmune, Experimental ; drug therapy ; enzymology ; genetics ; Female ; Gene Expression Regulation ; drug effects ; Nerve Regeneration ; drug effects ; genetics ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Inbred Lew ; Signal Transduction ; drug effects ; genetics ; Spinal Cord ; drug effects ; metabolism ; pathology ; Tablets