The adhesion molecule and cytokine profile of multiple sclerosis lesions

The expression of the adhesion molecules, vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1), and their respective receptors on leukocytes, very late activation antigen-4 (VLA-4) and lymphocyte function–associated antigen-1 (LFA-1), together with a selection of proinflammatory and immunomodulatory cytokines (interleukin [IL]-1, IL-2, IL-4, IL-10, tumor necrosis factor-α [TNF-α], transforming growth factor-β [TGF-β], and interferon-γ [IFN-γ]) was examined by immunocytochemistry in multiple sclerosis (MS) lesions of different ages and compared with central nervous system (CNS) tissue from other neurological diseases, both inflammatory and noninflammatory, and normal CNS tissue. These molecules play key roles in lymphocytic infiltration and interactions during tissue inflammation and are in large part normally not expressed by CNS cells. High levels of expression of all the molecules tested were found in MS, particularly in chronic active lesions. Positivity for all molecules was also seen in other neurological diseases, even in noninflammatory conditions. There was some suggestion that the VCAM-1/VLA-4 adhesion pathway was expressed at higher levels in chronic MS lesions, while ICAM-1/LFA-1 was used more uniformly in lesions of all ages. Of the cytokines examined, there was increased expression of TNF-α and IL-4 in MS; this was found to be statistically significant when compared with noninflammatory neurological diseases. The expression of most adhesion molecules and some cytokines was negligible in normal CNS tissue although low-level reactivity for ICAM-1 TGF-β, IL-4, TNF-α, and IL-10 was detected, perhaps indicative of immunoregulatory mechanisms. Microglial cells and astrocytes were the major CNS cell types expressing cytokines. The results indicate a potential in the CNS for widespread induced expression of molecules involved in the inflammatory cascade. No adhesion or cytokine molecule or pattern of expression unusual for MS was apparent.     

Transforming growth factor-β1 suppresses autoantigen-induced expression of pro-inflammatory cytokines but not of interleukin-10 in multiple sclerosis and myasthenia gravis

Multiple sclerosis (MS) is associated with high levels of circulating T lymphocytes that respond to the myelin antigens myelin basic protein (MBP) and proteolipid protein (PLP) by producing various cytokines including interferon-γ (IFN-γ) that makes MS worse and transforming growth factor-β (TGF-β), an endogenously produced immunosuppressant that might act beneficially. To further define the role of TGF-β in MS, we examined the effects of recombinant TGF-β1 (rTGF-β1) on autoantigen-mediated regulation of cytokines in MS and myasthenia gravis (MG). Blood mononuclear cells (MNC) were cultivated with or without rTGF-β1, and with or without autoantigen or the recall antigen PPD. MNC expressing cytokine mRNA were detected after in situ hybridization with radiolabeled cDNA oligonucleotide probes. Femtogram concentrations of rTGF-β1 suppressed MBP-, PLP- and PPD-induced upregulation of IFN-γ, IL-4, IL-6, tumor necrosis factor-α (TNF-α), TNF-α and perforin in MS, and acetylcholine receptor (AChR)-induced augmentation of these pro-inflammatory cytokines in MG, but had no effects on autoantigen- or PPD-induced expression of IL-10 or TGF-β itself. rTGF-β1 also suppressed numbers of myelin antigen-reactive IFN-γ- and IL-4-secreting cells in MS and AChR-reactive IFN-γ and IL-4 secreting cells in MG. The selective suppressive effects of TGF-β1 on autoantigen-induced upregulation of pro-inflammatory cytokines makes TGF-β1 attractive as a treatment alternative in MS and MG.     

Interleukin-6 mRNA expression by cortical neurons in culture: Evidence for neuronal sources of interleukin-6 production in the brain

In this study, we investigated the capacity of murine cortical neurons to express interleukin-6 (IL-6) mRNA and protein in culture. Using in situ hybridization techniques, IL-6 mRNA was localized to neuronal cells in these cultures. Moreover, IL-6 mRNA expression as measured by in situ and PCR was shown to be upregulated by the proinflammatory cytokines interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). This was consistent with the dose and time-dependent increases in IL-6 secreted protein observed from cultures stimulated with IL-1β and TNF-α. Taken together, the data suggest that neurons are capable of participating more directly in the CNS cytokine network than previously thought and may play an important role in the inflammatory response activities in the brain.     

Transforming growth factor–beta inhibition of cytokine-induced vascular cell adhesion molecule-1 expression in human astrocytes

Leukocyte transmigration across the blood-brain barrier (BBB) is a cardinal feature of central nervous system (CNS) inflammation. Astrocytes form an integral part, both structurally and functionally, of the BBB. Vascular cell adhesion molecule-1 (VCAM-1), a member of the immunoglobulin gene superfamily, is involved in extravasation into inflamed tissues and activation of T-lymphocytes. In this study, we investigated the role of TGF-β, an immunosuppressive cytokine, in regulating cytokine-induced VCAM-1 expression in astrocytes. Human astroglioma cell lines and primary human fetal astrocytes were examined for VCAM-1 gene expression after treatment with proinflammatory cytokines (TNF-α, IL-1β, IFN-γ) in the absence or presence of TGF-β. Astroglioma cell lines as well as primary human fetal astrocytes expressed low levels of VCAM-1 constitutively, and the proinflammatory cytokines induced marked increases in VCAM-1 expression, particularly TNF-α and IL-1β. The inclusion of TGF-β1 or TGF-β2 with the proinflammatory cytokines inhibited VCAM-1 gene expression to varying degrees (33–93%) in all the astroglioma cell lines and primary fetal cells. These results indicate that TGF-β is an important regulator of cytokine induced VCAM-1 expression on astrocytes and may prove useful clinically in controlling CNS inflammation. GLIA 22:171–179, 1998. © 1998 Wiley-Liss, Inc.     

Interleukin-1β (IL-1β)-induced modulation of the hypothalamic IL-1β system,tumor necrosis factor-α, and transforming growth factor-β1 mRNAs in obese (fa/fa) and lean (Fa/Fa) Zucker rats: Implications to IL-1β feedback systems and cytokine–cytokine interactions

Interleukin-1β (IL-1β) induces anorexia, fever, sleep changes, and neuroendocrine alterations when administered into the brain. Here, we investigated the regulation of the IL-1β system (ligand, receptors, receptor accessory protein, and receptor antagonist), tumor necrosis factor-α (TNF-α), transforming growth factor (TGF)-β1, and TGF-α mRNAs in the hypothalamus of obese (fa/fa) and lean (Fa/Fa) Zucker rats in response to the intracerebroventricular microinfusion of IL-1β (8.0 ng/24 hr for 72 hr, a dose that yields estimated pathophysiological concentrations in the cerebrospinal fluid). IL-1β increased IL-1β, IL-1 receptor types I and II (IL-1RI and IL-1RII), IL-1 receptor accessory protein soluble form (IL-1R AcP II), IL-1 receptor antagonist (IL-1Ra), TNF-α, and TGF-β1 mRNAs in the hypothalamus from obese and lean rats. IL-1β–induced IL-1β system and ligand (IL-1β, TNF-α, and TGF-β1) mRNA profiles were highly intercorrelated in the same samples. Levels of membrane-bound IL-1R AcP and TGF-α mRNAs did not change. Heat-inactivated IL-1β had no effect. The data suggest 1) the operation of an IL-1β feedback system (IL-1β/IL-1RI/IL-1R Acp II/IL-1RII/IL-1Ra) and 2) potential cytokine–cytokine interactions with positive (IL-1β ←→ TNF-α) and negative (TGF-β1 → IL-1β/TNF-α) feedback. Dysregulation of the IL-1β feedback system and the TGF-β1/IL-1β-TNF-α balance may have implications for neurological disorders associated with high levels of IL-1β in the brain. J. Neurosci. Res. 49:541–550, 1997. © 1997 Wiley-Liss, Inc.     

Correlation of matrix metalloproteinases-2 and -9 with proinflammatory cytokines in Guillain-Barré syndrome

The role of matrix metalloproteinases (MMPs) and cytokines in the pathogenesis of Guillain-Barré syndrome (GBS) largely remains unknown. We studied the role of MMP-2, MMP-9, tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) in disease progression and recovery of patients with GBS. Sixty-five patients with GBS and 68 healthy controls were enrolled in the study. Serum levels of MMP-2, MMP-9, TNF-α, and IL-1β were analyzed by ELISA, and activities of MMPs were measured by zymography. Expression of MMP-9, TNF-α, and IL-1β was higher in the progressive phase and lower in the recovery phase of GBS than in controls. A positive correlation of MMP-2 with IL-1β and MMP-9 with TNF-α and IL-1β was observed with progressive-phase GBS. The study shows that up-regulation of MMP-9 along with proinflammatory cytokines (TNF-α and IL-1β) in the early course appears to be associated with immune-mediated disease progression resulting from inflammation in the peripheral nervous system, whereas, during the later phase, down-regulation of MMP-9 and proinflammatory cytokines is implicated in recovery from the disease.     

Interleukin 1-β- and tumor necrosis factor-α-mediated regulation of ICAM-1 gene expression in astrocytes requires protein kinase C activity

Several adhesion molecules including intracellular adhesion molecule-1 (ICAM-1) are expressed by astrocytes, the predominant glial cell of the central nervous system (CNS). Such molecules are important in the trafficking of leukocytes to sites of inflammation, and in lymphocyte activation. ICAM-1 is constitutively expressed by neonatal rat astrocytes, and expression is enhanced by the proinflammatory cytokines interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ), with IL-1β and TNF-α being the strongest inducers. In this study, we have examined the nature of the second messengers involved in ICAM-1 gene expression induced by the cytokines IL-1β and TNF-α. Our results indicate that stimuli related to protein kinase C (PKC) such as the phorbol ester phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187 increase ICAM-1 mRNA expression, whereas cyclic nucleotide analogs and PKA agonists have no effect. Pharmacologic inhibitors of PKC such as H7, H8, and calphostin C inhibit ICAM-1 gene expression inducible by IL-1β and TNF-α. Prolonged treatment of astrocytes with PMA results in a time-dependent downregulating of the PKC isoforms α, δ, and ?, and a concomitant diminution of ICAM-1 mRNA expression induced by IL-1β, TNF-α, and PMA itself at specific time points post-PMA treatment. These data, collectively, demonstrate a role for various PKC isoforms in IL-1β and TNF-α enhancement of ICAM-1 gene expression in rat astrocytes. © 1995 Wiley-Liss, Inc.     

TNF-α and TGF-β act synergistically to kill Schwann cells

Interactions between cytokines and Schwann cells (SC) are important in development, repair, and disorders of the peripheral nervous system (PNS). Tumor necrosis factor-α (TNF-α) and transforming growth factor-β (TGF-β) are two prominent cytokines which may be involved in these processes and their gene products are upregulated in some experimental neuropathies. This study focuses on thein vitro effects of these cytokines, both singly and in combination, on cultured SC. Expression of both Type I and Type II TNF-α receptors was demonstrated on the SC surface by immunocytochemistry. Treatment of SC with a combination of TNF-α plus TGF-β causes significant detachment and cell death while treatment with each cytokine alone is not significantly cytotoxic. When compared with control cultures, SC treated with the combination of cytokines exhibit an increase in the number of cells with condensed nuclei and evidence of DNA fragmentation, characteristics consistent with cells undergoing programmed cell death. Thus, TNF-α plus TGF-β induce SC loss of adhesion which is predominantly due to cell death. Apoptotic mechanisms are likely to contribute to some extent to this cell death. These findings provide in vitro evidence to support the hypothesis that cytokines can directly damage SC in PNS disorders. J. Neurosci. Res. 53:747–756, 1998. © 1998 Wiley-Liss, Inc.     

Postinjury treatment with rolipram increases hemorrhage after traumatic brain injury

The pathology caused by traumatic brain injury (TBI) is exacerbated by the inflammatory response of the injured brain. Two proinflammatory cytokines that contribute to inflammation after TBI are tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). From previous studies using the parasagittal fluid-percussion brain injury model, we reported that the anti-inflammatory drug rolipram, a phosphodiesterase 4 inhibitor, reduced TNF-α and IL-1β levels and improved histopathological outcome when administered 30 min prior to injury. We now report that treatment with (±)-rolipram given 30 min after injury significantly reduced TNF-α levels in the cortex and hippocampus. However, postinjury administration of (±)-rolipram significantly increased cortical contusion volume and increased atrophy of the cortex compared with vehicle-treated animals at 10 days postinjury. Thus, despite the reduction in proinflammatory cytokine levels, histopathological outcome was worsened with post-TBI (±)-rolipram treatment. Further histological analysis of (±)-rolipram-treated TBI animals revealed significant hemorrhage in the contused brain. Given the well-known role of (±)-rolipram of increasing vasodilation, it is likely that (±)-rolipram worsened outcome after fluid-percussion brain injury by causing increased bleeding.     

Cytokine phenotype of human autoreactive T cell clones specific for the immunodominant myelin basic protein peptide (83–99)

Experimental allergic encephalomyelitis (EAE), an animal model resembling multiple sclerosis (MS), is mediated by myelin antigen-specific CD4+ T cells secreting cytokines such as interferon-γ (IFN-γ), tumor necrosis factor-β (TNF-β), and the proinflammatory cytokine TNF-α—all associated with the T-helper-1 (Th1) T cell subset. Based on numerous similarities between MS and EAE, it has been postulated that Th1-like T cells are involved in the pathogenesis of MS. Production of proinflammatory cytokines such as IFN-γ and, in particular, TNF-α/β by autoreactive T cells is considered crucial for the initiation and amplification of inflammatory brain lesions and possibly also for direct myelin damage. In contrast, regulatory cytokines such as interleukin-4 (IL-4), IL-10, and IL-13, which are associated with the Th2-like phenotype, may play a role in the resolution of relapses. Although the human T cell response to myelin basic protein (MBP) is well characterized in terms of antigen specificity, HLA restriction, and T cell-receptor (TCR) usage, little is known about the cytokine pattern of these autoreactive T cells. To gain such information, conditions for studying cytokine secretion by human autoreactive T cell clones (TCC) were established. The cytokine secretion profile of human autoreactive CD4+ TCC, specific for myelin basic protein peptide (83–89) [MBP(83–99)], a candidate autoantigen in MS, was investigated. Our results show that TCC cytokine production in long-term culture was stable. In addition, the correlation of various cytokines within specific TCC revealed differences compared to murine T cells. The comparison of 30 human MBP(83–99)-specific TCC demonstrated heterogeneity in cytokine secretion, with a continuum between Th1- and Th2-like cells rather than distinct Th1 or Th2 subsets. These data are important for further investigation of the potential role of cytokines in the inflammatory process of MS, and provide a powerful tool to investigate therapeutic interventions with respect to their influence on cytokine secretion of autoreactive T cells. © 1996 Wiley-Liss, Inc.     

Macrophage and microglial responses to cytokines in vitro: Phagocytic activity,proteolytic enzyme release,and free radical production

Certain cytokines are believed to play a key role in the development of autoimmune demyelinating diseases. Little is known, however, about the effects of these cytokines in the regulation of the key event in myelin destruction, the phagocytosis of myelin by phagocytic cells. We investigated the effects of certain cytokines and growth factors on cultured peritoneal macrophages and microglia in respect to their various functions, phagocytosis, secreted proteolytic activity, and oxidative activity. Interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), and lipopolysaccharide (LPS), all proinflammatory factors, actually decreased (IFN-γ and LPS), or had no effect (TNF-α) on myelin phagocytosis by macrophages, but substantially increased phagocytic activity by microglia. Surprisingly, interleukins 4 and 10 (IL-4 and IL-10), considered to be downregulating cytokines, increased phagocytic activity by macrophages, while with microglia, IL-4 had no effect, but IL-10 almost doubled myelin phagocytosis. Transforming growth factor-β (TGF-β) had no significant effect on either cell. These cytokines did not affect proteolytic secretion in microglia, while IFN-γ and LPS induced a doubling of the secreted proteases. This proteolytic activity was almost completely suppressed by calpain inhibitors, although some gelatinase appeared to be present. Microglia exerted much more oxidative activity on the membranes than macrophages, and granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin 1β (IL-1β) significantly increased microglial oxidative activity. The pattern of responses of macrophages and microglia to the cytokine types indicate that in cytokine-driven autoimmune demyelinating disease, microglia may be the more aggressive cell in causing tissue injury by phagocytosis and oxidative injury, while infiltrating macrophages may produce most of the proteolytic activity thought to contribute to myelin destruction. J. Neurosci. Res. 54:68–78, 1998. © 1998 Wiley-Liss, Inc. This article is a US Government work and, as such, is in the public domain in the United States of America.     

Multiple sclerosis: myelin basic protein induced mRNA expression of proinflammatory cytokines in mononuclear cells is suppressed by interferon-β 1b in vitro

Beta-interferon (IFN-β) is a promising treatment in multiple sclerosis (MS), reducing the exacerbation rate and MRI lesion burden, as well as the disease progression in relapsing-remitting MS. IFN-β was originally defined by its antiviral effects, but the interest has recently been focused on its immunomodulatory properties. Myelin basic protein (MBP) is one of several autoantigens considered to be the target for autoaggressive immune responses, which eventually might lead to the development of MS. To study in-vitro effects of IFN-β1b on MBP induced cytokine expression, mRNA for the Th1 cytokines IFN-γ and TNF-α, the Th2 related IL-4 and IL-6, the cytolytic perforin and the immune response downregulating TGF-β was measured with in situ hybridization after culture of blood mononuclear cells (MNC) in the presence and absence of MBP. Numbers of cells expressing IFN-γ, TNF-α, perforin and IL-4 mRNA were significantly suppressed after culture with 10 U/ml IFN-β1b. No such effect was seen on MBP induced IL-6 or TGF-β mRNA expression. These observations suggest that one of the major effects of IFN-β1b is the induction of a shift in the cytokine mRNA profile towards a more immunosuppressive pattern. In parallel in vitro tests, the control substance dexametasone (40 μg/ml) reduced the numbers of cells expressing mRNA for all cytokines under study with the exception of TGF-β, to an extent equal to or even more pronounced than IFN-β1b.     

Cytokine modulation of murine microglial cell superoxide production

Activated microglia may contribute to two opposite effects during inflammation within the central nervous system: host defense against microorganisms and neuronal injury. Each of these processes may be mediated by the generation of reactive oxygen intermediates by activated microglia. We investigated the effects of two proinflammatory cytokines, interferon (IFN)-β and tumor necrosis factor (TNF)-α, and of the anti-inflammatory cytokine, transforming growth factor (TGF)-β, on murine microglial cell superoxide (O₂) production upon stimulation with phorbol myristate acetate (PMA). Priming of microglia with IFN-β or TNF-α resulted in a dose-dependent enhancement of O₂ release in response to PMA. The priming effects of these two cytokines were additive, suggesting that they acted by independent mechanisms. We also found that IFN-β and TNF-β stimulated the release of bioactive TGF-β and that treatment of microglial cell cultures with TGF-β antagonized the priming effects of IFN-β and TNF-α on O₂ production. The results of this study have implications for understanding the mechanisms by which cytokines and microglia may contribute to host defense as well as to injury of the brain. © 1995 Wiley-Liss, Inc.     

辛伐他汀抑制大鼠实验性自身免疫性脑脊髓炎的实验研究

目的 探讨辛伐他汀(STATINS)对实验性自身免疫性脑脊髓炎IEAE)的作用及机理.方法 Wistar大鼠55只采用随机数字表法分为EAE组(15只)、STATINS组(15只)、雷公藤(TP)组(15只)、正常对照组(10只).使用STATINS干预EAE大鼠,以TP为阳性对照,观察大鼠P53蛋白、IL-6、TNF-α、TGF-β的表达变化.结果 与EAE组相比,STATINS组发病率降低、临床症状减轻、体质量下降减少、病灶数减少、潜伏期延长,而TP组临床症状减轻、病灶数减少,差异均有统计学意义(P＜0.05),TP组体质量变化、潜伏期、发病率无显变化,差异无统计学意义(P＞0.05);STATINS组IL-6和TNF-α的表达降低,P53蛋白和TGF-β的表达增高;TP组仅TNF-α的表达降低,差异均有统计学意义(P＜0.05).与TP组相比较,STATINS组P53蛋白与TGF-β的表达增加,差异有统计学意义(P＜0.05),而TNF-α及Ⅱ-6的表达差异无统计学意义(P＞0.05).结论 STATINS可以有效抑制EAE.其可能的机制是抑制IL-6和TNF-α等促炎症因子的表达,促进P53蛋白与TGF-β的表达,效果可能优于TP.     

白藜芦醇对蛛网膜下腔出血后神经炎症的作用和机制研究

目的 研究白藜芦醇对蛛网膜下腔出血（subarachnoid hemorrhage,SAH）后血肿区脑组织神经炎症的作用和机制。方法 将48只成年雄性SD大鼠随机分为三组：假手术组,SAH组和SAH+白藜芦醇处理组,每组16只。采用枕大池两次注血法构建SAH模型。SAH组和SAH+白藜芦醇组在构建模型前15 min和构建模型后5min分别给予生理盐水或白藜芦醇各一次。于构建模型后72小时利用NSS评分评估大鼠的神经功能,然后处死大鼠并获取保存脑组织。利用ELISA检测脑组织内促炎因子IL-1,IL-6、TNF-α和抗炎因子IL-4,IL-10、TGF-β的表达水平,利用RT-PCR检测小胶质细胞M1型特征性基因IL-1β、CD32和M2型特征性基因CD206、Arginase-1的表达水平。结果 与假手术组相比,SAH组大鼠神经功能下降（P<0.05）,脑组织中促炎因子IL-1,IL-6、TNF-α和抗炎因子IL-4,IL-10、TGF-β的表达水平升高（P<0.05）,小胶质细胞M1型特征性基因IL-1β、CD32和M2型特征性基因CD206、Arginase-1的表达水平也升高（P<0.05）。与生理盐水处理组相比,白藜芦醇处理组神经功能损伤程度下降（P<0.05）,脑组织中促炎因子IL-1,IL-6、TNF-α表达水平降低、抗炎因子IL-4,IL-10、TGF-β的表达水平升高（P<0.05）,小胶质细胞M1型特征性基因IL-1β、CD32表达水平降低、M2型特征性基因CD206、Arginase-1的表达水平升高（P<0.05）。结论 白藜芦醇通过促进SAH后小胶质细胞由M1型向M2型转换,从而减轻了神经炎症和神经功能损伤。     

Mesencephalic Astrocyte-Derived Neurotrophic Factor Inhibits Oxygen–Glucose Deprivation-Induced Cell Damage and Inflammation by Suppressing Endoplasmic Reticulum Stress in Rat Primary Astrocytes

Astrocyte inflammation plays important roles both in physiological and pathological processes in the central nervous system (CNS). Ischemic injury in the CNS causes damage to astrocytes and the release of proinflammatory cytokines, such as tumor necrosis factor-α, interleukin-1β, and interleukin-6. This current study investigates whether mesencephalic astrocyte-derived neurotrophic factor (MANF) inhibits oxygen–glucose deprivation (OGD)-induced cell damage and inflammatory cytokine secretion by suppressing endoplasmic reticulum stress in rat primary astrocytes. We found that MANF alleviated OGD-induced astrocyte damage and rescued the cell viability, and the upregulation of GRP78 (endoplasmic reticulum (ER) stress marker) and NF-κB p65 (one of the central mediators of proinflammatory pathways) induced by OGD were significantly reduced by preincubation of MANF. In addition, the increases of secretion and mRNA expression levels of the proinflammatory cytokines IL-1β, IL-6, and TNF-α in astrocytes induced by OGD were significantly suppressed by MANF. These findings demonstrate that MANF shows the potential to alleviate cell damage and inflammation in rat primary astrocytes by suppressing ER stress, indicating that MANF plays an important role in astrocyte inflammation and functioning and may suggest a promising strategy for neuroprotection in the CNS.     

Cytokine production in the central nervous system of Lewis rats with experimental autoimmune encephalomyelitis: dynamics of mRNA expression for interleukin-10, interleukin-12, cytolysin,tumor necrosis factor α and tumor necrosis factor β

The kinetics of mRNA expression in the central nervous system (CNS) for a series of putatively disease-promoting and disease-limiting cytokines during the course of experimental autoimmune encephalomyelitis (EAE) in Lewis rats were studied. Cytokine mRNA-expressing cells were detected in cryosections of spinal cords using in situ hybridization technique with synthetic oligonucleotide probes. Three stages of cytokine mRNA expression could be distinguished: (i) interleukin (IL)-12, tumor necrosis factor (TNF)-β (=lymphotoxin-α) and cytolysin appeared early and before onset of clinical signs of EAE; (ii) TNF-α peaked at height of clinical signs of EAE; (iii) IL-10 appeared increasingly at and after clinical recovery. The early expression of IL-12 prior to the expression of interferon-γ (IFN-γ) mRNA shown previously is consistent with a role of IL-12 in promoting proliferation and activation of T helper 1 (Th1) type cells producing IFN-γ. The TNF-β mRNA expression prior to onset of clinical signs favours a role for this cytokine in disease initiation. A pathogenic effector role of TNF-α was suggested from these observations that TNF-α mRNA expression roughly paralleled the clinical signs of EAE. This may be the case also for cytolysin. IL-10-expressing cells gradually increased to high levels in the recovery phase of EAE, consistent with a function in down-regulating the CNS inflammation. From these data we conclude that there is an ordered appearance of putative disease-promoting and -limiting cytokines in the CNS during acute monophasic EAE.     

The Effects of Mouse Recombinant Resistin on mRNA Expression of Proinflammatory and Anti-Inflammatory Cytokines and Heat Shock Protein-70 in Experimental Stroke Model

Background

Our recent research showed that resistin has a neuroprotective effect against stroke-induced injury through suppressing apoptosis and oxidative stress. However, the molecular mechanism of neuroprotection of resistin is unclear. This work was designed to examine the effect of mouse recombinant resistin on mRNA expression of Tumor necrosis factor-α (TNF-α), Interleukin-1β (IL-1β), Interleukin-10 (IL-10), Transforming growth factor-β1 (TGF- β1), and Heat shock protein-70 (HSP-70) in mouse model of stroke.

Interleukin-1β increases release of endothelin-1 and tumor necrosis factor as well as reactive oxygen species by peripheral leukocytes during experimental subarachnoid hemorrhage

In the subarachnoid hemorrhage (SAH) blood mixes with cerebrospinal fluid, what starts immunoinflammatory processes - increased synthesis of proinflammatory cytokines, and formation of reactive oxygen species (ROS), resulting in pre-activation of different populations of peripheral leukocytes. Migration of leukocytes to the brain parenchyma through broken blood brain barrier may produce extra brain tissue injury besides of that resulting from SAH. We examined in adult rats the effect of interleukin-1β (IL-1β) neutralization on secretion of cytokines as well as production of ROS in the course of SAH. SAH was produced by injection of 150 μL of autologous arterial blood into cisterna magna. In 50% of animals, IL-1beta activity was inhibited by intracerebroventricular administration of anti-rat IL-1β antibodies. Ninety minutes or 24 hrs following surgery, blood samples were drawn from the extraorbital plexus and centrifuged to obtain two leukocyte subpopulations - polymorphonuclear (PMN) and mononuclear (MN). The chemiluminescence, a hallmark of ROS synthesis, was measured in PMNs. In supernatants from MNs cultures, concentrations endothelin-1 (ET-1), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were assessed. SAH caused the increase ofn PMNs chemiluminescence as well as the increase of production of ET-1 and TNF-α by MNs but had no influence on IL-6 concentration. Neutralization of IL-1β resulted in significant decrease of chemiluminescence as well as concentration of both ET-1 and TNF-α, while IL-6 concentration was increased. These revealed an important role of IL-1β in the activation of peripheral leukocytes in the course of subarachnoid hemorrhage.