Business Unit Biomedical Research, TNO Quality of Life, P.O. Box 2215, 2301 CE Leiden, The Netherlands.
Flavonoids are food components that appear to have potential beneficial health effects. There is a range of in vitro studies supporting the anti-oxidant and anti-inflammatory properties of flavonoids. Previously, we demonstrated that in vitro flavonoids, including luteolin and apigenin, inhibit proliferation and IFN-gamma production by murine and human autoimmune T cells. In the present study, we examined the effects of oral flavonoids as well as of curcumin on autoimmune T cell reactivity in mice and on the course of experimental autoimmune encephalomyelitis (EAE), a model for multiple sclerosis. Continuous oral administration of flavonoids significantly affected antigen-specific proliferation and IFN-gamma production by lymph node-derived T cells following immunization with an EAE-inducing peptide. Both luteolin and apigenin suppress proliferative responses as they did in vitro, whereas IFN-gamma production on the other hand was enhanced. Other flavonoids exerted differential effects on proliferation and IFN-gamma production. The effects of flavonoids and curcumin on EAE were assessed using either passive transfer of autoimmune T cells or active disease induction. In passive EAE, flavonoids led to delayed recovery of clinical symptoms rather than to any reduction in disease. In active EAE, the effects were less pronounced but also, in this case, the flavonoid hesperitin delayed recovery. Oral curcumin had overall mild but beneficial effects. Our results indicate that oral flavonoids fail to beneficially influence the course of EAE in mice but, instead, suppress recovery from acute inflammatory damage.
Mesh-terms: Administration, Oral; Animals; Cells, Cultured; Comparative Study; Encephalomyelitis, Autoimmune, Experimental :: chemically induced; Encephalomyelitis, Autoimmune, Experimental :: pathology; Encephalomyelitis, Autoimmune, Experimental :: physiopathology; Female; Flavonoids :: administration & dosage; Flavonoids :: adverse effects; Glycosides :: administration & dosage; Growth Inhibitors :: administration & dosage; Growth Substances :: administration & dosage; Luteolin :: administration & dosage; Mice; Mice, Inbred Strains; Quercetin :: administration & dosage; Recovery of Function :: drug effects; Recovery of Function :: physiology; T-Lymphocytes :: cytology; T-Lymphocytes :: drug effects; T-Lymphocytes :: pathology;
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Qun Shan,
Jun Lu,
Yuanlin Zheng,
Jing Li,
Zhong Zhou,
Bin Hu,
Zifeng Zhang,
Shaohua Fan,
Zhen Mao,
Yong-Jian Wang,
Daifu Ma
Key Laboratory for Biotechnology on Medicinal Plants of Province, School of Life Science, Xuzhou Normal University, Xuzhou 221116, China.
Purple sweet potato color (PSPC), a naturally occurring anthocyanin, has a powerful antioxidant activity in vitro and in vivo. This study explores whether PSPC has the neuroprotective effect on the aging mouse brain induced by D-galactose (D-gal). The mice administrated with PSPC (100 mg/kg.day, 4 weeks, from 9th week) via oral gavage showed significantly improved behavior performance in the open field and passive avoidance test compared with D-gal-treated mice (500 mg/kg.day, 8 weeks). We further investigate the mechanism involved in neuroprotective effects of PSPC on mouse brain. Interestingly, we found, PSPC decreased the expression level of glial fibrillary acidic protein (GFAP), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2), inhibited nuclear translocation of nuclear factor-kappaB (NF-kappaB), increased the activity of copper/zinc superoxide dismutase (Cu/Zn-SOD) and catalase (CAT), and reduced the content of malondialdehyde (MDA), respectively. Our data suggested that PSPC attenuated D-gal-induced cognitive impairment partly via enhancing the antioxidant and anti-inflammatory capacity.
Department of Angiology, Private Healthcare Institution SANA, Pszczyna, Poland. mariansimka@poczta.onet.pl.
Multiple sclerosis is an autoimmune disease characterized by multifocal areas of inflammation and demyelination within the central nervous system. The mechanism that triggers the disease remains elusive. However, recent findings may indicate that multiple sclerosis, at its source, could be a hemodynamic disorder. It has been found that multiple sclerosis patients exhibit significant stenoses in extracranial veins draining the central nervous system (in azygous and internal jugular veins), which are associated with significant pressure gradients measured across strictures. Such anatomic venous abnormalities were not found in the control group of healthy subjects. In this review, it is hypothesized that pathological refluxing venous flow in the cerebral and spinal veins increases the expression of adhesion molecules, particularly intercellular adhesion molecule-1 (ICAM-1), by the cerebrovascular endothelium. This, in turn, could lead to the increased permeability of the blood-brain barrier. Inflamed and activated endothelium could secrete proinflammatory cytokines, including GM-CSF and TGF-beta In these settings, monocytes could transform into antigen-presenting cells and initiate an autoimmune attack against myelin-containing cells. Consequently, a potential therapeutic option for multiple sclerosis could be pharmacotherapy with either substances that strengthen the tight-junctions barrier, or with agents that reduce the expression of adhesion molecules. In addition, surgical correction could be an option in some anatomical variants of pathologic venous outflow. We are optimistic that a hemodynamic approach to the multiple sclerosis pathogenesis can open a new chapter of investigations and treatment of this debilitating neurologic disease.
Cytokine Research Laboratory, Department of Experimental Therapeutics, The University of Texas M. D. Anderson Cancer Center, Houston, TX, United States.
Although safe in most cases, ancient treatments are ignored because neither their active component nor their molecular targets are well defined. This is not the case, however, with curcumin, a yellow-pigment substance and component of turmeric (Curcuma longa), which was identified more than a century ago. For centuries it has been known that turmeric exhibits anti-inflammatory activity, but extensive research performed within the past two decades has shown that the this activity of turmeric is due to curcumin, a diferuloylmethane. This agent has been shown to regulate numerous transcription factors, cytokines, protein kinases, adhesion molecules, redox status and enzymes that have been linked to inflammation. The process of inflammation has been shown to play a major role in most chronic illnesses, including neurodegenerative, cardiovascular, pulmonary, metabolic, autoimmune and neoplastic diseases. In the current review, we provide evidence for the potential role of curcumin in the prevention and treatment of various proinflammatory chronic diseases. These features, combined with the pharmacological safety and negligible cost, render curcumin an attractive agent to explore further.
Department of Experimental Therapeutics, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA. aggarwal@mdanderson.org
Turmeric, derived from the plant Curcuma longa, is a gold-colored spice commonly used in the Indian subcontinent, not only for health care but also for the preservation of food and as a yellow dye for textiles. Curcumin, which gives the yellow color to turmeric, was first isolated almost two centuries ago, and its structure as diferuloylmethane was determined in 1910. Since the time of Ayurveda (1900 Bc) numerous therapeutic activities have been assigned to turmeric for a wide variety of diseases and conditions, including those of the skin, pulmonary, and gastrointestinal systems, aches, pains, wounds, sprains, and liver disorders. Extensive research within the last half century has proven that most of these activities, once associated with turmeric, are due to curcumin. Curcumin has been shown to exhibit antioxidant, anti-inflammatory, antiviral, antibacterial, antifungal, and anticancer activities and thus has a potential against various malignant diseases, diabetes, allergies, arthritis, Alzheimer's disease, and other chronic illnesses. These effects are mediated through the regulation of various transcription factors, growth factors, inflammatory cytokines, protein kinases, and other enzymes. Curcumin exhibits activities similar to recently discovered tumor necrosis factor blockers (e.g., HUMIRA, REMICADE, and ENBREL), a vascular endothelial cell growth factor blocker (e.g., AVASTIN), human epidermal growth factor receptor blockers (e.g., ERBITUX, ERLOTINIB, and GEFTINIB), and a HER2 blocker (e.g., HERCEPTIN). Considering the recent scientific bandwagon that multitargeted therapy is better than monotargeted therapy for most diseases, curcumin can be considered an ideal "Spice for Life".
Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, Xuzhou Normal University, Xuzhou 221116, China; Institute of Molecular Medicine and Genetics Research Center, School of Basic Medical Science, Southeast University, Nanjing 210009, China.
We assessed the neuroprotective effects of quercetin-feeding at doses of 5 and 10mg/(kgday) on Kunming mice injected daily with d-gal (50mg/(kgday)) by behavioral tests. Quercetin-fed mice showed higher activity upon induction by new environmental stimuli, lower anxiety and higher novelty-seeking behavior in the open field tasks, and significantly improved learning and memory ability in step-through and Morris water Maze tests compared with d-gal-treated mice. We further investigated the mechanisms involved in the neuroprotective effects of quercetin on mouse brain. Quercetin significantly increased superoxide dismutase (SOD) activity and decreased the malondialdehyde (MDA) level. These results imply that quercetin can reverse oxidant impairment induced by d-gal in mouse brain. Neurotoxicity is also associated with Ca(2+) overload induced by oxidant stress. Quercetin could maintain the Ca(2+) homeostasis in the brain of d-gal-treated mice. Furthermore, we also examined the expression of growth-associated protein GAP43 mRNA in mouse brain by in situ hybridization. We found that quercetin dramatically elevated the GAP43 mRNA expression in the brain of d-gal-treated mice to regenerate normal function of neurons against the cellular injury caused by d-gal.
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Division of Biomedical Research, TNO Prevention and Health, P.O. Box 2215, 2301 CE Leiden, The Netherlands.
Plant-derived flavonoids are inhibitors of various intracellular processes, notably phosphorylation pathways, and potential inhibitors of cellular autoimmunity. In this study, the inhibiting effects of various flavonoids on antigen-specific proliferation and interferon-gamma (IFN-gamma) production by human and murine autoreactive T cells were evaluated in vitro. T-cell responses were evaluated for the human autoantigen alpha B-crystallin, a candidate autoantigen in multiple sclerosis, and for the murine encephalitogen proteolipid protein peptide PLP (139-151). The flavones apigenin and luteolin were found to be strong inhibitors of both murine and human T-cell responses while fisitin, quercitin, morin and hesperitin, members of the subclasses of flavonoles and flavanones, were ineffective. Antigen-specific IFN-gamma production was reduced more effectively by flavones than T-cell proliferation, suggesting that the intracellular pathway for IFN-gamma production in T cells is particularly sensitive to flavone inhibition. These results indicate that flavones but not flavanoles or flavanones are effective inhibitors of the potentially pathogenic function of autoreactive T cells. The effects of flavones were the same for human and murine autoreactive T cells, stressing the usefulness of animal models of autoimmunity for further studies on the effects of flavonones on autoimmune diseases.
Department of Biosciences, TNO Quality of Life, Leiden, The Netherlands.
Summary Tolerance induction to prevent activation of a naïve T-cell repertoire has been well documented in rodents and can be readily achieved by intravenous, oral or intranasal administration of antigen in the absence of adjuvants. In autoimmune diseases such as multiple sclerosis (MS) the presence of an established memory/effector T-cell repertoire against self-antigens is likely to be more relevant than the potential reactivity of naive T cells. Methods to eliminate such an established T-cell response are less well understood. In this study, we explored the effectiveness of intravenous soluble antigen to eliminate a pre-existing T-cell response against alphaB-crystallin, a candidate autoantigen in MS. We used mice that are deficient for the target antigen. This condition allowed for a vigourous T-cell and antibody response to develop upon immunization, and eliminated all possible endogenous mechanisms of tolerance for alphaB-crystallin that are found in normal rodents. When applied 3 weeks after priming with alphaB-crystallin, intravenous administration of soluble antigen almost completely abrogated the established T-cell response in a dose-dependent manner as evidenced by T-cell non-responsiveness in tolerized animals to a re-challenge with antigen in complete Freund's adjuvant. Evaluating delayed-type hypersensitivity responses after tolerance induction revealed that the tolerizing effect was achieved within 24 hr. Furthermore, the tolerizing effect was found to be antigen-specific and long lasting. In contrast, serum antibody levels were markedly increased. Our data clarify that in the absence of any natural form of immune regulation, antigen-specific memory/effector T cells can be effectively silenced by intravenous antigen.
Department of Biosciences, TNO Quality of Life, PO Box 2215, 2301 CE Leiden, The Netherlands.
While myelin-reactive T cells are widely believed to play a pathogenic role in multiple sclerosis (MS), no substantial differences appear to exist in T-cell responses to myelin antigens between MS patients and healthy subjects. As an example, indistinguishable peripheral T-cell responses and serum antibody levels have been found in MS patients and healthy controls to alpha B-crystallin, a dominant antigen in MS-affected brain myelin. This suggests that additional factors are relevant in allowing myelin-reactive T cells to become pathogenic. In this study, we examined whether the inflammatory state of the CNS is relevant to the pathogenicity of alpha B-crystallin-specific T cells in mice. In normal mice, T-cell responses against alpha B-crystallin are limited by robust immunological tolerance. Reactive T cells were therefore generated in alpha B-crystallin-deficient mice, and these T cells were transferred into C57BL/6 recipients. While such a transfer in itself never induced any clinical signs of experimental autoimmune encephalomyelitis (EAE) in healthy recipient mice, acute EAE could be induced in animals that had been infected 7 days before with the avirulent A7(74) strain of Semliki Forest virus (SFV). SFV infection alone did not induce clinical disease, nor did it alter the expression levels of the target antigen. Our findings indicate that at least in mice, alpha B-crystallin-specific T cells can trigger EAE but only when prior viral infection has induced an inflammatory state in the CNS that helps recruit and activate T cells.
Rega Institute for Medical Research, University of Leuven, 3000 Leuven, Belgium.
The small heat shock protein alphaB-crystallin is considered as a candidate autoantigen in multiple sclerosis (MS) lesions. Gelatinase B or matrix metalloproteinase (MMP)-9 is a proteinase establishing various disease-promoting feedback loops in autoimmune diseases. Human alphaB-crystallin was digested with natural gelatinase B and all cleavage sites were identified by a combined approach of mass spectrometry and peptide sequencing analysis. Previously identified immunodominant and cryptic epitopes of alphaB-crystallin in mice and rats were generated and largely left intact by MMP-9 processing. The alphaB-crystallin peptide 1-16, generated as a remnant epitope, provoked a significant T cell response in alphaB-crystallin knockout mice. None of the remnant peptides was encephalitogenic when injected intracerebrally into mice or induced MMP-9 in vitro. Gelatinase B is thus able to release T cell epitopes from intact alphaB-crystallin, but their pathogenic role remains unclear.
Delta Crystallon BV, Leiden, The Netherlands. hans.vannoort@tno.nl
The role of Toll-like receptors (TLRs) in the CNS is only starting to be uncovered. As in peripheral organs, multiple TLRs are dynamically expressed. They are involved in mounting a host-defense response against microbial invasion of the CNS. The many different TLRs expressed on microglia are likely the most important first line of defense in this respect. Intriguingly, microglial TLR tend to trigger a very standard cytokine and chemokine response, irrespective of the type of TLR agonist they meet. The main purpose of this standardized response by microglia may be to recruit the assistance by other cells rather than to immediately mount a destructive response toward invaders. As is generally the case for microglial responses, TLR-mediated responses can also work out in either beneficial or detrimental ways, depending on the strength and timing of the activating signal. Yet, the role of TLRs in the CNS extends well beyond controlling host-defense responses alone. Other cells in the CNS, including astrocytes, neurons, and oligodendrocytes, can also express multiple functional TLRs upon activation. These play important roles in tissue development, cellular migration, and differentiation; in limiting inflammation; and in mounting repair processes following trauma. The TLR-mediated reactions of these other neural cells to TLR agonists is highly cell specific and does not necessarily resemble that of microglia at all. It appears likely that endogenous agonists for TLRs are particularly relevant to activate these endogenous TLR functions on neural cells, also during development when microbial invaders have not yet entered the stage. In this chapter, current data are reviewed to highlight the emerging variety of functional roles of TLRs in the CNS.
Emergency Medicine Residency Program, University of Toronto, Toronto, Ontario, Canada.
OBJECTIVE: We sought to determine whether the use of currently issued gowns delays initiation of chest compressions and ventilations during cardiopulmonary resuscitation and whether simple gown modifications can reduce this delay. METHODS: Firefighter defibrillation instructors were allocated into pairs and videotaped while performing standardized cardiac arrest scenarios. Three scenarios were compared:"no gown,""standard gown" and "modified gown." Key time intervals were extracted from videotaped data. RESULTS: Ninety-five scenarios were analyzed. Mean time interval to chest compression was 39 seconds (95% confidence interval [CI] 34-43) for "no gown" scenarios, 71 seconds (95% CI 66-77) for "standard gown" scenarios and 59 seconds (95% CI 54-63) for "modified gown" scenarios (p < 0.001). Time to first ventilation was 146 seconds (95% CI 134-158), 238 seconds (95% CI 224-253) and 210 seconds (95% CI 198-223) in the 3 groups, respectively (p < 0.001). Post hoc testing showed that the time differences between all groups were statistically significant. CONCLUSION: Standard gowns protect front-line care providers but cause significant delays to chest compressions and ventilations, potentially increasing patient morbidity and mortality. Minor gown modifications, including pre-tied neck straps and longer waist ties that tie in front, allow for easier use and shorter delays to time-critical interventions. Future research is required to reduce care delays while maintaining adequate protection of emergency medical service providers from infectious disease.
Ella A Zuiderwijk-Sick,
Céline van der Putten,
Malika Bsibsi,
Ilona P Deuzing,
Willem de Boer,
Carla Persoon-Deen,
Ivanela Kondova,
Leonie A Boven,
Johannes M van Noort,
Bert A 't Hart,
Sandra Amor,
Jeffrey J Bajramovic
Activated microglia are found in a variety of neuroinflammatory disorders where they have attributed roles as effector as well as antigen-presenting cells (APC). Critical determinants for the multifaceted role of microglia are the differentiation potential of microglia and their mode of activation. In this study, we have investigated the effects of M-CSF and GM-CSF-mediated differentiation of adult primate microglia on their cellular phenotype, antigen presentation, and phagocytic function as well as on Toll-like receptor (TLR)-mediated responses. We show that although cell morphology and expression levels of activation markers were markedly different, differentiation with either factor yielded microglia that phenotypically and functionally resemble macrophages. Both M-CSF and GM-CSF-differentiated microglia were responsive to TLR1/2, 2, 3, 4, 5, 6/2, and 8-mediated activation, but not to TLR7 or 9-mediated activation. Intriguingly, M-CSF-differentiated microglia expressed higher levels of TLR8-encoding mRNA and protein, and produced larger amounts of proinflammatory cytokines in response to TLR8-mediated activation as compared to GM-CSF-differentiated microglia. While differentiation of adult microglia by growth factors that can be produced endogenously in the central nervous system is thus unlikely to change their APC function, it can alter their innate responses to infectious stimuli such as ssRNA viruses. Resident primate microglia may thereby help shape rather than initiate adaptive immune responses.(c) 2007 Wiley-Liss, Inc.
Shalina S Ousman,
Beren H Tomooka,
Johannes M van Noort,
Eric F Wawrousek,
Kevin O'conner,
David A Hafler,
Raymond A Sobel,
William H Robinson,
Lawrence Steinman
Department of Neurology and Neurological Sciences, Stanford University.
alphaB-crystallin (CRYAB) is the most abundant gene transcript present in early active multiple sclerosis lesions, whereas such transcripts are absent in normal brain tissue. This crystallin has anti-apoptotic and neuroprotective functions. CRYAB is the major target of CD4(+) T-cell immunity to the myelin sheath from multiple sclerosis brain. The pathophysiological implications of this immune response were investigated here. We demonstrate that CRYAB is a potent negative regulator acting as a brake on several inflammatory pathways in both the immune system and central nervous system (CNS). Cryab(-/-) mice showed worse experimental autoimmune encephalomyelitis (EAE) at the acute and progressive phases, with higher Th1 and Th17 cytokine secretion from T cells and macrophages, and more intense CNS inflammation, compared with their wild-type counterparts. Furthermore, Cryab(-/-) astrocytes showed more cleaved caspase-3 and more TUNEL staining, indicating an anti-apoptotic function of Cryab. Antibody to CRYAB was detected in cerebrospinal fluid from multiple sclerosis patients and in sera from mice with EAE. Administration of recombinant CRYAB ameliorated EAE. Thus, the immune response against a negative regulator of inflammation, CRYAB, in multiple sclerosis, would exacerbate inflammation and demyelination. This can be countered by giving CRYAB itself for therapy of ongoing disease.
Laurie J Morrison,
Laura M Visentin,
Marian Vermeulen,
Alex Kiss,
Robert Theriault,
Don Eby,
Jonathan Sherbino,
Richard Verbeek
Prehospital and Transport Medicine Research Program, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada; Department of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada; Division of Emergency Medicine, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; Institute for Clinical and Evaluative Sciences, Toronto, Ontario, Canada.
STUDY OBJECTIVE: This study evaluates inter-rater reliability and comfort of BLS providers with the application of an out-of-hospital Basic Life Support Termination of Resuscitation (BLS TOR) clinical prediction rule. This rule suggests that continued BLS cardiac resuscitation is futile and can be terminated in the field if the following three conditions are met:(1) no return of spontaneous circulation;(2) no shock given prior to transport;(3) cardiac arrest not witnessed by EMS personnel. METHODS: Providers hypothetically applied the rule and rated their comfort level on a five-point Likert-type scale, from "very comfortable" to "very uncomfortable" during the prospective validation of a BLS TOR clinical prediction rule in out-of-hospital cardiac arrest conducted in 12 rural and urban communities [Morrison LJ, Visentin LM, Kiss A, et al. Validation of a rule for termination of resuscitation in out-of-hospital cardiac arrest. New Engl J Med 2006;355(5):478-87]. A Kappa score measured agreement between providers and compared to the correct interpretation of the rule. RESULTS: We compared mean comfort levels of providers who interpreted the rule correctly versus incorrectly. Of 1240 enrolled cases, 1184 (95.5%) had paramedic attendant forms and 1211 (97.7%) had driver forms and 1175 (94.7%) had both. Kappa for interpretation agreement between driver and attendant was 0.90 (95% CI, 0.87-0.92); between attendant and correct interpretation of the BLS TOR clinical prediction rule, 0.88 (95% CI, 0.85-0.91); between driver and correct interpretation of the BLS TOR clinical prediction rule, 0.88 (95% CI, 0.85-0.91). For instances in which both providers applied the rule correctly (607/635 [95.6%]), the providers were significantly more comfortable (chi(2)(4)=30.5, p<0.0001) than those instances in which they did not (28/635 [4.4%]. CONCLUSIONS: The vast majority of providers were able to apply the BLS TOR clinical prediction rule correctly and were comfortable doing so. This suggests that both reliability and comfort will remain high during routine application of the rule when paramedics are well trained as users of the rule.
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From the Division of Periodontology,* Department of Oral Health and Diagnostic Sciences, and the Center for Immunotherapy of Cancer and Infectious Diseases, Department of Immunology, University of Connecticut Health Center, Farmington, Connecticut.
Recent reports suggest that commensal bacteria may play a down-regulatory role in autoimmune disease. In the present studies, we demonstrate that phosphorylated dihydroceramides, uniquely structured lipids derived from the common human oral bacterium Porphyromonas gingivalis and from bacteria commonly found in the gastrointestinal tract and other organs, are capable of enhancing autoimmunity. We have previously reported that these lipids have proinflammatory effects on human fibroblasts in vitro and, in preliminary studies, have recovered these lipids from surgically removed human carotid atheroma, suggesting that they may play a role in human inflammatory disease. To investigate whether these lipids have functional effects on autoimmunity, we administered phosphorylated dihydroceramides to mice with the murine model of multiple sclerosis, experimental allergic encephalomyelitis (EAE). We find that these lipids, and particularly the phosphoethanolamine dihydroceramide (PE DHC) fraction, significantly enhanced EAE. Mechanistically, PE DHC enhances EAE in mice lacking natural killer T cells, fails to enhance EAE in Toll-like receptor 2 (TLR2)-deficient mice and, in vitro, induces dendritic cell interleukin-6 secretion in a TLR2-dependent manner. Finally, PE DHC-treated mice with EAE demonstrate a decreased percentage of spinal cord Foxp3+ T cells, suggesting that these lipids may affect regulatory aspects of adaptive immune responses. Overall, our results suggest that phosphorylated dihydroceramides derived from common human bacteria function as TLR2 ligands and may play a previously unrecognized role in human autoimmune diseases.
National Centre for Pharmaceutical Screening, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China; Key Laboratory of BioactiVe Substances and Resources Utilization of Chinese HerbalMedicine, Ministry of Education, China.
Luteolin is an important member of the flavonoid family. It exhibits strongly anti-inflammatory, anti-oxidant and phytoestrogen-like activities. In the present study, we examined the anti-amnesic and protective effects of luteolin against Ass(25-35)-induced toxicity in mice. Mice were given an intracerebroventricular injection of aggregated Ass(25-35) peptide. The learning and memory impairments, ultrastructural changes of cerebral cortex, cerebrovascular dysfunction and neuronal changes were detected after oral administration of luteolin continuously for 8 days. Our results demonstrate that oral administration of luteolin for 8 days for those Ass(25-35)-induced amnesic mice conferred robust neurovascular protection in Ass(25-35)-induced amnesia, involving the improvement of the spatial learning and memory capabilities, the modulation of microvascular function, the increase of regional cerebral blood flow values, the clearance of ROS, the improvement of cholinergic neuronal system, and the raise of BNDF level and its receptor TrkB expression in cerebral cortex.
Department of Neurology, Kinki University School of Medicine, Ohno-higashi, Osaka-Sayama, Osaka, Japan.
We investigated the possible therapeutic effect of cilostazol, a specific inhibitor of phosphodiesterase-3, for experimental autoimmune encephalomyelitis (EAE). Mice affected with EAE induced by inoculation with MOG(35-55) were fed with cilostazol or vehicle control. The clinical EAE scores of the cilostazol-fed mice were lower than those of the controls. Serum level of soluble intercellular adhesion molecule-1 was significantly lower in the cilostazol-fed mice than in the controls. In the recall responses with MOG(35-55), proliferation and IFN-gamma production by lymphocytes from cilostazol-fed mice were significantly reduced. Cilostazol may exhibit repressive effects on EAE by reducing the antigen-specific T-cell response and decreasing the expression of the adhesion molecules. Cilostazol is a hopeful choice for the treatment of multiple sclerosis.
Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan.
The MTT (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) assay is widely accepted as a simple and reproducible method for determining cell proliferation or cytotoxicity in vitro. In this study, we show that the flavonoids quercetin, rutin and luteolin but not apigenin can reduce MTT in the absence of live cells in the following order: quercetin >> rutin > luteolin > apigenin. Moreover, this reduction can be influenced by medium type and serum. The final concentrations of the flavonoids used were 200, 100, 50, 25 and 12.5 mug/mL. MTT reduction in Dulbecco's Modified Eagle's Medium (DMEM) is statistically higher than those in RPMI 1640 and F12 media, which are generally similar. Particularly for luteolin, MTT reduction is considerably higher with serum than without serum. In the case of quercetin at 50 mug/mL, a serum concentration of even only 0.01% is sufficient to significantly enhance MTT reduction versus that at 0%(P < 0.05). Serum at concentrations ranging from 0% to 5% also dose-dependently affects the pattern of formazan crystal formation. In the presence of 0.156-5% serum, the formazan crystals gradually change from being small, numerous and scattered to being large, few and clumpy. The authors hypothesize that flavonoid structure, nutrient concentration in the culture medium as well as serum components directly affect MTT reduction by flavonoids in the absence of cells.
The iron chelator, Desferal, suppressed disease activity of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), and it has been tested in pilot trials for MS. The administration regimen of Desferal is cumbersome and prone to complications. Orally-deliverable, iron chelators have been developed that circumvent these difficulties, and the objective of this study was to test an oral chelator in EAE. SJL mice with active EAE were randomly assigned to receive deferiprone (150 mg/kg) or vehicle (water) 2x/day via gavage. EAE mice given deferiprone had significantly less disease activity and lower levels of inflammatory cell infiltrates (revealed by H&E staining) than EAE mice administered vehicle. T-cell infiltration, assessed by anti-CD3 immunohistochemical staining, also was reduced, although not significantly. Splenocytes cultured from naïve SJL mice were stimulated with anti-CD3 and anti-CD28 with or without 250 muM deferiprone. While ~39% of costimulated splenocytes without deferiprone underwent division, only ~2.8% of costimulated splenocytes with deferiprone divided and the latter cells were only 53% as viable as the former. Deferiprone had no effect on proliferation or viability of cells that were not costimulated. In summary, deferiprone effectively suppressed active EAE disease and it inhibited T-cell function. Multiple Sclerosis 2007; 13: 1118-1126. http://msj.sagepub.com.
Innate immune cells may regulate adaptive immunity by balancing different lineages of T cells and providing negative costimulation. In addition, CD11b(+)Gr-1(+) myeloid-derived suppressor cells have been described in tumor, parasite infection, and severe trauma models. In this study, we observe that splenic CD11b(+) cells markedly increase after experimental autoimmune encephalomyelitis (EAE) immunization, and they suppress T cell proliferation in vitro. Although >80% of CD11b(+) cells express varying levels of Gr-1, only a small population of CD11b(+)Ly-6C(high) inflammatory monocytes (IMC) can efficiently suppress T cell proliferation and induce T cell apoptosis through the production of NO. IFN-gamma produced by activated T cells is essential to induce IMC suppressive function. EAE immunization increases the frequencies of IMC in the bone marrow, spleen, and blood, but not in the lymph nodes. At the peak of EAE, IMC represent approximately 30% of inflammatory cells in the CNS. IMC express F4/80 and CD93 but not CD31, suggesting that they are immature monocytes. Furthermore, IMC have the plasticity to up-regulate NO synthase 2 or arginase 1 expression upon different cytokine treatments. These findings indicate that CD11b(+)Ly-6C(high) IMC induced during EAE priming are powerful suppressors of activated T cells. Further understanding of suppressive monocytes in autoimmune disease models may have important clinical implications for human autoimmune diseases.
Scutellaria baicalensis Georgi is one of the important medicinal herbs widely used for the treatment of various inflammatory diseases in Asia. Baicalin (BA) is a bioactive anti-inflammatory flavone found abundantly in Scutellaria baicalensis Georgi. To explore the therapeutic potential of BA, we examined the effects of systemic administration of the flavone (5 and 10 mg/kg, ip) on relapsing/remitting experimental autoimmune encephalomyelitis (EAE) induced by proteolipid protein 139-151 in SJL/J mice, an experimental model of multiple sclerosis. The mice treated with PBS or BA at day -1 and for 3 consecutive days were observed daily for clinical signs of disease up to 60 days after immunization. In the PBS-EAE group, neurological scores were: incidence (100%), mean day of onset (8.0 +/- 0.73), peak clinical score (3.0 +/- 0.4), and cumulative disease index (141.8 +/- 19.4). In the BA-EAE group (5 or 10 mg kg-1 day-1, respectively), incidence (95 or 90%), mean day of onset (9.0 +/- 0.80 or 9.2 +/- 0.75; P = 0.000), peak clinical score (2.2 +/- 0.3 or 2.0 +/- 0.3; P = 0.000), and cumulative disease index (75.9 +/- 10.1 or 62.9 +/- 8.4; P = 0.000) decreased, accompanied by the histopathological findings (decrease of dense mononuclear infiltration surrounding vascellum) for the spinal cord. Additionally, the in vitro effects of BA (5, 10, and 25 microM) on mononuclear cells collected from popliteal and inguinal lymph nodes of day-10 EAE mice were evaluated using an MTT reduction assay for cell proliferation, and ELISA to measure IFN-g and IL-4 cytokines. Compared with the control group, BA caused an increase in IL-4 (EAE-DMSO: 3.56 +/- 0.42 pg/mL vs EAE-BA (5, 10, and 25 microM): 6.03 +/- 1.1, 7.83 +/- 0.65, 10.54 +/- 1.13 pg/mL, respectively; P < 0.001); but inhibited IFN-g (EAE-DMSO: 485.76 +/- 25.13 pg/mL vs EAE-BA (5, 10, and 25 microM): 87.08 +/- 9.24, 36.27 +/- 5.44, 19.18 +/- 2.93 pg/mL, respectively; P < 0.001) and the proliferation of mononuclear cells (EAE-DMSO: 0.73 +/- 0.021 vs EAE-BA (5, 10, and 25 microM): 0.41 +/- 0.015, 0.31 +/- 0.018, 0.21 +/- 0.11, respectively; P < 0.001) in a concentration-dependent manner. The results suggest that BA might be effective in the treatment of multiple sclerosis.
Tali Garin,
Ariel Rubinstein,
Nikolaos Grigoriadis,
Shlomo Nedvetzki,
Oded Abramsky,
Rachel Mizrachi-Koll,
Carla Hand,
David Naor,
Dimitrios Karussis
Lautenberg Center for General and Tumor Immunology, Hebrew University-Hadassah Medical School, Jerusalem, Israel.
Standard CD44 (CD44s) and its alternatively spliced variants (CD44v) were found to be associated with the metastatic potential of tumor cells, and with cell migration of autoimmune inflammatory cells, including cells involved in experimental autoimmune encephalomyelitis (EAE). The aim of the present study was to evaluate whether induction of anti-CD44 immune reactivity, through cDNA vaccination could down-regulate EAE. Our vaccination technique involved the insertion of CD44s or CD44v cDNA into a silicone tube filled with 2.5 cm long segment of hydroxylated-polyvinyl acetate wound dressing sponge (forming a virtual lymph node) which was implanted under the skin of SJL/J mice immunized with myelin antigens for EAE induction. Animals vaccinated with CD44v cDNA developed significantly less severe EAE when compared with sham vaccinated animals or animals vaccinated with CD44s cDNA. The in vitro proliferation of lymphocytes was preserved regarding myelin antigens and mitogens. Histopathological examinations revealed a significant reduction of EAE lesions and enhanced apoptosis in central nervous system (CNS)-infiltrating cells of the successfully vaccinated animals. Such methods of cDNA vaccination with CD44 could be applicable in inflammatory CNS diseases, like multiple sclerosis.
AIM: To construct a novel eukaryotic expression plasmid including the recombinant immunotoxin DT390-mRantes and treat experimental autoimmune encephalomyelitis (EAE) in mice. METHODS: EAE in C57BL/6 mice were induced by the extracted MBP. The mRantes fragment was inserted into the eukaryotic expression plasmid SRalpha containing DT390. Then cationic liposome-embedded plasmid DNA was injected into the muscles of the hind-limbs in mice. The effect of DT390-mRantes was evaluated by observing clinical symptoms, pathological changes of brain, relative cytokine of peripheral blood, and the proportion of T cells and B cells. RESULTS: The recombinant immunotoxin DT390-mRantes was successfully constructed. Compared the mice in treated group with those in untreated group the clinical symptoms of EAE were alleviated, the infiltration of inflammatory cells were decreased, the IFN-gamma level was fallen, and the ratio of T/B cells was decreased. CONCLUSION: The recombinant immunotoxin DT390-mRantes has distinct effects on EAE in mice, which may be used for beneficial reference to the therapy of MS.


