Wistar大鼠实验性变态反应性脑脊髓炎的模型建立

目的:建立Wistar大鼠多病程实验性变态反应性脑脊髓炎(EAE)的动物模型,并进行病理学研究,为多发性硬化(MS)的研究提供实验依据。方法:以豚鼠全脊髓匀浆(GPSCH)为抗原免疫Wistar大鼠建立EAE的动物模型,并在光镜下观察不同发病类型EAE的病理改变。结果:根据病理和临床表现可将Wistar大鼠EAE模型分为5种发病形式:急性型、缓解-复发型、持续进展型、良性型和隐匿型。光镜下可见不同发病时期的EAE的病理改变有所不同,但都以血管"袖套"状改变、脑室周围及白质脱髓鞘改变为主,伴有神经元肿胀变性。结论:首次建立了Wistar大鼠多病程EAE,是研究多发性硬化的理想动物模型。     

Dendritic cells in experimental allergic encephalomyelitis and multiple sclerosis

The mechanisms by which autoimmune diseases are triggered and by which the activation of autoreactive T cells is initiated and maintained are not yet fully understood. As the most potent antigen presenting cells (APC), and also being responsible for antigen transport as well as primary sensitisation of T cells, dendritic cells (DC) are capable of breaking the state of self-ignorance and inducing aggressive autoreactive T cells. In the development of autoimmune diseases, different types of DC exhibit distinct properties for inducing Th1/Th2 cell responses. Appropriate cytokines can convert immunogenic DC to tolerogenic DC. Utilizing the possibility to promote the tolerogenic effects of DC, a new therapeutic tool might soon become available to treat multiple sclerosis and other autoimmune diseases.     

Chronic relapsing experimental allergic encephalomyelitis: its value as an experimental model for multiple sclerosis

Summary Comparison of the pathohistology of chronic relapsing experimental allergic encephalomyelitis (CR-EAE) and multiple sclerosis (MS) reveals a close similarity. Thus, CR-EAE appears to be a valuable model for the study of pathogenetic factors leading to the formation of MS lesions, although the induction of the disease may be different (active sensitization with CNS antigens and adjuvant in CR-EAE versus unknown etiology in MS). CR-EAE furthermore mimicks the pathohistological patterns of other related human inflammatory demyelinating diseases (i.e., acute perivenous leukoencephalomyelitis and acute hemorrhagic leukoencephalomyelitis). The expression of an acute, predominantly inflammatory versus chronic inflammatory demyelinating disease in this model depends upon the time interval between sensitization and sampling of the animals. Recent evidence is discussed that a cooperation between cellular and humoral immune mechanisms, directed against multiple CNS antigens, is responsible for the formation of large demyelinated plaques in EAE and MS.Supported by Austrian Science Research Fund, Project S25/07     

Autonomic involvement in multiple sclerosis: a pupillometric study

To study pupillary autonomic function in multiple sclerosis (MS), we examined 36 subjects with low disability, preserved visual acuity and no recent history (2 years) of optic neuritis or actual visual complaints. Compared to controls, MS patients showed a greater dilatator reaction with darkness and, for the light reflex, a lower amplitude and contraction rate and a greater recovery of pupillary diameter 5 s after the stimulus. Within the MS group, no difference was found comparing patients with or without the following characteristics: nuclear magnetic resonance imaging evidence of midbrain lesions; increased visual evoked potential P100 latency; and a previous history of optic neuritis. No correlation was found between P100 latency, duration of disease and pupillometric parameters. Our results indicate that in MS patients there is autonomic dysfunction with a reduction of parasympathetic tone and a relative increase in sympathetic dilatator tone to the pupils. We suggest that pupillary abnormalities could be due to non-specific impairment of the central pathways subserving pupil functions.     

Nonathymulin treatment of multiple sclerosis: double-blind pilot study

We carried out a randomized, double-blind, placebo-controlled trial of Nonathymulin (NT, synthetic serum thymic factor) in patients with evolutive multiple sclerosis (MS) and moderate disability. Forty matched patients were treated with subcutaneous NT or placebo for 6 months and followed for another 6 months. There was no significant difference in treatment and control groups in the Kurtzke. Disability scores, Ambulation Index and Functional Scale. No significant side effects were recorded. NT is not effective in treating evolutive and moderately disabled MS.     

调节性T细胞在实验性变态反应性脑脊髓炎和多发性硬化发病中的作用

调节性T细胞(regulatory T cells,Treg)是一类具有免疫调节功能的T细胞哑群.近年来,Treg细胞在实验性变态反应性脑脊髓炎(experimental allergical encephalomyelitis,EAE)、多发性硬化(multiple sclerosis,MS)发病中的作用越来越受到关注,小鼠Treg细胞缺失可导致特异性自身免疫性疾病,增加Treg细胞的功能可以减轻或抑制EAE.最近的研究结果表明,MS本身也伴随着成熟Treg细胞的受损或功能障碍.     

Prevention of experimental allergic encephalomyelitis by ganglioside GM4

Guinea pigs inoculated with a mixture of myelin basic protein and the myelin-specific ganglioside, sialosylgalactosylceramide (G_M4), do not develop the signs or neuropathology of experimental allergic encephalomyelitis. The results indicate that G_M4 cloaks the basic protein molecule so that it is no longer immunopathogenic in these animals. The interaction of basic protein with G_M4, previously shown in vitro, appears to be relevant to the pathogenesis of experimental allergic encephalomyelitis in guinea pigs.     

Evaluation of myocardial muscle functional parameters in patients with multiple sclerosis

Structural and functional parameters of myocardium were evaluated with 2D⁺ Doppler echocardiography in two similar age groups of MS patients: S₁: 12 subjects in 3–4° EDSS (Expanded Disability Status Scale), S₂: 12 subjects in 5–7° EDSS. The control group comprised 12 healthy subjects temporarily (at least 1 month) immobilized due to lower limb fractures. Investigations were performed in the supine position and 3 min after tilting to the erect position. Symptoms of organic myocardial injury which might have caused its insufficiency were not observed in any subjects. All structural parameters evaluated by this method did not differ significantly in the examined groups. Symptoms suggesting myocardial insufficiency were found in patients from group S₂. Statistically significant decrease of ejection fraction (EF) and cardiac output (CO) was observed in the supine position of S₂ patients as compared to S, and the controls. These symptoms intensified in the erect position in S₂ patients and they were accompanied by the decreased values of stroke volume (SV). The fact that in the majority of patients orthostatic hypotonia was not observed and that those disorders were not compensated by significant intensification of heart rate suggest to us that besides disorders resulting from autonomic nervous system dysfunction they may have been caused by secondary myocardial injury in the course of MS.     

Experimental allergic encephalomyelitis

Summary Previous studies have shown that Strain 13 guinea pigs sensitised for experimental allergic encephalomyelitis (EAE) as adults usually develop an acute, fatal form of disease while animals inoculated as juveniles usually display a chronic relapsing form. The present study reports that following repeated short-interval blood sampling by cardiac puncture for the estimation of lymphocyte populations, some adult Strain 13 guinea pigs sensitised for acute EAE unexpectedly survived and developed chronic EAE, while a group of juveniles sensitised for chronic EAE and bled under the same conditions, developed a more severe, acute form of EAE. It is suggested that this reversal of disease course was related to the depletion of circulating factors.     

Lesional accumulation of RhoA(+) cells in brains of experimental autoimmune encephalomyelitis and multiple sclerosis

Aim: Infiltration of autoantigen-specific T cells and monocytes into the central nervous system is essential for the development of both experimental autoimmune encephalomyelitis (EAE) and multiple sclerosis (MS). RhoA is one of the best-known members of Rho GTPases, and inhibition of RhoA has been shown to attenuate the progression of EAE. The aim of this study was to investigate the expression of RhoA in brains of EAE rats and MS tissue. Methods: EAE was induced by immunization with the synthetic peptide gpMBP68-84 in rats, and clinical severity was scored. RhoA expression pattern was investigated in brains of EAE rats at different time points and in different lesions of brain tissue specimens from six MS brains and five neuropathologically unaffected controls by immunohistochemistry. Methods: In EAE rat brains, accumulation of RhoA⁺ cells reached maximal levels around Day 13, correlating to the clinical severity of EAE, and up-regulation lasted until the recovery stage of the disease. Double-labelling experiments showed that the major cellular sources of RhoA were reactive macrophages/microglia. While RhoA⁺ cells in normal human brain parenchyma were rarely observed, RhoA expression was found to be spatially associated with MS lesions, showing a marked decrease from active lesions via chronic stages to its near absence in normal-appearing white matter. In addition, major RhoA⁺ cells in brain parenchyma of MS were identified to be activated macrophages/microglia. Conclusion: Our present data indicated that RhoA may play an important role during the effector phase of EAE and MS. Therefore, RhoA inhibitors might be a therapeutic option for MS patients.     

Experimental allergic encephalomyelitis: Modulation by intraventricular injection of myelin basic protein

Antigen-induced suppression and therapy of experimental allergic encephalomyelitis in Lewis rats was studied using guinea pig myelin basic protein administered either intravenously or intraventricularly. A small intraventricular dose of basic protein was effective when given shortly before the onset of clinical signs (suppression) as well as when given after the disease (therapy). In contrast, the same amount of basic protein administered intravenously was effective only in the therapy of disease.     

Sweating impairment in patients with multiple sclerosis

Objectives – To measure sweating in patients with multiple sclerosis (MS). Materials and methods – Sweating was measured by an evaporimeter after a heating stimulus in 29 MS patients and in 15 healthy control subjects. Results – The MS patients sweated markedly less than the controls. After 10 min of heating the sweating was significantly lower in the forehead (P = 0.034), feet (right, P = 0.033; left, P = 0.037) and legs (right, P = 0.043; left, P = 0.029) of the MS patients than in those of the controls. After 15 min of heating the difference was statistically significant only in the feet (right, P = 0.043; left, P = 0.029). The Expanded Disability Status Scale score correlated inversely with sweating at 15 min of heating in the left hand (r = 0.42, P < 0.05), and in the left (r = 0.36, P < 0.05) and right foot (r = 0.37, P < 0.05). Conclusions – MS is associated with an impairment in thermoregulatory sweating which seems to be related to the disease severity.     

雌激素对实验性变态反应性脑脊髓炎大鼠发病影响的研究

目的探讨雌激素对实验性变态反应性脑脊髓炎(EAE)的影响。方法将30只大鼠随机分为EAE组及大、小剂量雌激素干预组,每组10只,制作EAE模型,大、小剂量雌激素干预组分别给予皮下注射苯甲酸雌二醇1 mg/kg/d、250μg/kg/d,连续10 d,观察各组的发病情况并采用HE染色观察脑和脊髓组织病理变化。结果大、小剂量雌激素干预组的临床症状均较EAE组轻,表现为发病率减少、潜伏期延长、进展期缩短、高峰期神经功能损害较轻。病理切片提示雌激素干预组脑和脊髓炎症细胞浸润明显减少,其中以大剂量组更明显。结论雌激素对多发性硬化动物模型EAE具有保护作用,且与剂量相关。     

Suppression of relapsing experimental allergic encephalomyelitis by mizoribine: Clinical,histological and immunohistochemical studies

Experimental allergic encephalomyelitis (EAE) is an organspecific, cell-mediated inflammatory autoimmune disease and is regarded as a model of multiple sclerosis (MS). Relapsing EAE was induced in Lewis rats and the effect of mizoribine on the relapsing EAE was examined clinically, histologically and immunohistochemically. Mizoribine (4-carbamoyl-1-β-D-ribofuranosyl-imidazolium-5-olate), an immunosuppresive agent, is an imidazole nucleotide isolated from a culture infiltrate of Eupenicillium brefeldianum M-2166. Most control and treated rats suffered two attacks. Treated rats at a dose of 10mg/kg per day showed clinically significant delay of the disease attacks and histologically reduction of infiltrating cell number. Treated rats at a dose of 20 mg/kg per day showed a further delay in the attacks and attenuation of clinical signs, and a smaller number of inflammatory cells and Ia positive cells were revealed at the first attack. This study suggests that mizoribine suppresses the clinical severity and inflammation in relapsing EAE.     

Pentoxifylline inhibits experimental allergic encephalomyelitis

Pentoxifylline, a widely used methylxanthine, has been proven to inhibit the production and action of the cytokine TNF α. Since it has been suggested that TNF α is the major cytokine involved in the pathogenesis of multiple sclerosis, we tested pentoxifylline for its capacity to prevent experimental allergic encephalomyelitis (EAE). 26 Lewis rats with acute EAE were treated with either pentoxifylline or saline. The pentoxifylline treated rats showed a significantly lower incidence of clinical signs as well as significantly lower histological inflammation. The exact mechanism of this preventive effect remains to be clarified but it might be mainly related to inhibition of TNF α release from central nervous system macrophages.     

Focal brain damage enhances experimental allergic encephalomyelitis in brain and spinal cord

The immunological basis of multiple sclerosis (MS) is well recognized but the factors inducing MS lesions are unclear. In this study, we test the hypothesis that focal brain injury, inflicted during the pre-clinical stages of experimental allergic encephalomyelitis (EAE), will enhance the severity of immunological damage in the cerebral hemispheres and spinal cord. Acute EAE was induced in 30 Lewis rats by the injection of guinea pig spinal cord homogenate in complete Freund's adjuvant. A cryolesion to the surface of the left cerebral hemisphere was induced at 3 days (n=6) or 8 days (n=10) post-inoculation (pi) and animals were killed at 15 days pi. Control animals were EAE only (n = 9), cryolesion only (n=4), EAE and sham cryolesion (n=5) and normal animals (n=3). Brain and spinal cord were stained by immunocytochemistry using W3/13 (T-lymphocytes) OX6 (MHC Class II) and GFAP (astrocytes) antibodies. The results showed a 2-fold increase in the number of EAE lesions in the brain with significant and widespread increase of MHC Class II antigen expression by microglia, in the cryolesion EAE 8 days p.i when compared with EAE only animals. The pattern of enhancement suggests that it is due to (i) local spread of tissue or serum factors from the cryolesion; (ii) neural factors affecting remote regions of the CNS; (iii) stimulation of the immune system which may occur due to products of brain injury draining to regional cervical lymph nodes. Investigation of the mechanisms involved may prove fruitful in establishing factors which initiate, aggravate or ameliorate brain damage in multiple sclerosis.     

Heart rate variability in multiple sclerosis during a stable phase

Objectives – Multiple sclerosis (MS) frequently causes disturbances of autonomic functions. Cardiovascular dysautonomia has been studied by classic autonomic tests and, recently, by heart rate variability analysis in some isolated periods. Multiple authors recommended performing heart rate variability analysis with a 24 h ECG recording to increase its sensitivity. Material and methods – We analyzed the heart rate variability in time and frequency domains in 34 MS patients and 24 age and sex-matched healthy control subjects, in order to evaluate the effects of MS on sympathetic and parasympathetic cardiovascular regulatory functions measured from 24-h electrocardiogram. Results – Low frequency power (0.01) and low frequency/high frequency power (0.01) were significantly higher in multiple sclerosis patients independently, all together or in subgroups. Very low frequency (0.01) and high frequency (0,001) power were higher in less affected multiple sclerosis patients. Variability in time domain (0.05) were lower in most affected multiple sclerosis patients. Conclusions – These results suggest that multiple sclerosis causes cardiovascular autonomic dysregulation manifesting as impaired heart rate variability. This illness seems to cause an increase in sympathetic cardiovascular tone; the parasympathetic tone is most variable and depends on clinical and paraclinical findings, but the illness progression seems to provoke a decrease in it.     

Chronic relapsing experimental allergic encephalomyelitis (CREAE) in plasminogen activator inhibitor-1 knockout mice: the effect of fibrinolysis during neuroinflammation

During neuroinflammation in multiple sclerosis (MS) fibrinogen, not normally present in the brain or spinal cord, enters the central nervous system through a compromised blood–brain barrier. Fibrin deposited on axons is ineffectively removed by tissue plasminogen activator (tPA), a key contributory factor being the upregulation of plasminogen activator inhibitor-1 (PAI-1). Aims: This study investigated the role of PAI-1 during experimental neuroinflammatory disease. Methods: Chronic relapsing experimental allergic encephalomyelitis (CREAE), a model of MS, was induced with spinal cord homogenate in PAI-1 knockout (PAI-1^−/−) and wild type (WT) mice, backcrossed onto the Biozzi background. Results: Disease incidence and clinical severity were reduced in PAI-1^−/− mice, with animals developing clinical signs significantly later than WTs. Clinical relapses were absent in PAI-1^−/− mice and the subsequent reduction in neuroinflammation was coupled with a higher capacity for fibrinolysis in spinal cord samples from PAI-1^−/− mice, in association with increased tPA activity. Axonal damage was less apparent in PAI-1^−/− mice than in WTs, implicating fibrin in both inflammatory and degenerative events during CREAE. Conclusions: PAI-1 is a potential target for therapy in neuroinflammatory degenerative diseases, allowing effective fibrin removal and potentially reducing relapse rate and axonal damage.     

A new model for multiple sclerosis: Chronic experimental allergic encephalomyelitis induced by immunization with cerebral endothelial cell membrane

Summary Multiple sclerosis is considered to be an autoimmune demyelinating disease of the central nervous system. Damage to the blood-brain barrier, of which endothelial cells are the main constitutent, occurs in multiple sclerosis, probably due to immunological mechanisms. We report here the results of immune-mediated damage to these cells, produced by immunizing guinea pigs with an endothelial cell membrane fraction. The fraction was obtained from cerebral endothelial cells grown in vitro and was free from myelin basic protein. The immunized animals developed a chronic neurological illness with evidence of delayed hypersensitivity to the cell membrane fraction but not to myelin antigens. Histological examination of the brain in the acute stage showed mononuclear cell infiltrates aroud blood vessels, while in the chronic phase large areas of demyelination, especially in the periventricular region, were present. This bore a striking similarity to the brain in multiple sclerosis. This may prove to be a useful new animal model for the investigation of the human demyelinating disease.Supported by the Intractable Diseases Division, Public Health Bureau, Japanese Ministry of Health and Welfare, the grant (61570385) from Japanese Ministry of Education and the Multiple Sclerosis Society of Great Britain     

Variation in experimental autoimmune encephalomyelitis scores in a mouse model of multiple sclerosis

Multiple sclerosis (MS) is a common demyelinating central nervous system disease associated with progressive physical impairment. To study the mechanism underlying disease pathogenesis and develop potential treatments, experimental autoimmune encephalomyelitis (EAE) is often used as an animal model. EAE can be induced in various species by introducing specific antigens, which ultimately result in motor dysfunction. Although the severity of the paralysis is indicated using the EAE score, there is no standard scoring system for EAE signs, and there is variability between research groups with regard to the exact EAE scoring system utilized. Here, we describe the criteria used for EAE scoring systems in various laboratories and suggest combining EAE score with another quantitative index to evaluate paralysis, such as the traveled distance, with the goal of facilitating the study of the mechanisms and treatment of MS.