实验性自身免疫性脑脊髓炎大鼠小胶质细胞的变化

目的　观察活化的小胶质细胞 (表达主要组织相容性抗原 )在实验性自身免疫性脑脊髓炎 ( EAE)大鼠脊髓中的变化 ,探讨 EAE大鼠发病相关生物学机制。方法　采用免疫组化法观察豚鼠全脊髓匀浆诱导的 Wistar大鼠 EAE过程中脊髓内表达 MHC 、MHC 类抗原的小胶质细胞的变化情况。结果　对照组脊髓内未发现表达 MHC抗原细胞 ,实验组脊髓内表达 MHC 抗原细胞与表达 MHC 抗原细胞的分布和形态一致 ,小胶质细胞变化与 EAE大鼠的病程一致。动物临床症状评分 2分和 3分 EAE大鼠脊髓表达 MHC抗原的小胶质细胞比评分 1分大鼠明显增高 ( P <0 .0 1 ) ,恢复期 EAE大鼠表达 MHC抗原的小胶质细胞明显减少 ( P <0 .0 1 )。结论　活化小胶质细胞与 EAE大鼠的病情相关 ,提示其可能通过表达 MHC抗原在 EAE大鼠的发病机制中具有作用     

大鼠实验性变态反应性脑脊髓炎中一氧化氮的变化

目的　观察外周和中枢一氧化氮 (NO)在大鼠实验性变态反应性脑脊髓炎 (EAE)中的动态变化 ,探讨EAE大鼠发病的相关生物学机制。方法　 采用免疫组化法和硝酸还原酶法 ,观察豚鼠全脊髓匀浆诱导的Wistar大鼠EAE的过程中 ,脊髓内表达iNOS胶质细胞与外周NO代谢物NO 2 和NO 3的变化。 结果　 对照组脊髓内未发现表达iNOS阳性细胞 ,表达iNOS的CNS胶质细胞可能是小胶质细胞 ,而且它的变化与EAE大鼠的病情一致 ,评分 2分和 3分EAE大鼠脊髓表达iNOS的小胶质细胞比评分 1分大鼠明显增多 (P <0 .0 1) ,恢复期EAE大鼠表达iNOS的小胶质细胞明显减少 (P <0 .0 1)。EAE大鼠外周血清NO值随症状程度加重而升高 ,但在EAE恢复期时仍保持较高水平。未发病大鼠血清NO值明显增高 ,与对照组之间具有显著性差异 (P <0 .0 1)。 结论　 小胶质细胞产生的NO可能在急性期EAE大鼠的发病中起重要作用     

大鼠坐骨神经切断后腰脊髓腹角内胶质细胞和神经元的可塑性变化

目的:探讨大鼠单侧坐骨神经切断后腰脊髓腹角胶质细胞和运动神经元的反应及其相互关系.方法:用免疫组织化学技术、HE染色和Tunnel法,观察坐骨神经切断后1,6,12,24 h及3,7和14 d腰脊髓腹角胶质原纤维酸性蛋白(GFAP)标记的星形胶质细胞、OX-42标记的小胶质细胞及运动神经元的变化.结果:坐骨神经切断侧腰脊髓腹角可见星形胶质细胞和小胶质细胞活化,星形胶质细胞的活化早于小胶质细胞;后期运动神经元发生凋亡,HE染色显示凋亡细胞周围为反应性OX-42阳性小胶质细胞和GFAP阳性星形胶质细胞包绕.结论:研究结果提示,坐骨神经切断后切断侧腰脊髓腹角活化的胶质细胞与凋亡的运动神经元之间关系密切.     

大鼠坐骨神经切断后腰脊髓腹角内胶质细胞和神经元的可塑性变化

目的：探讨大鼠单侧坐骨神经切断后腰脊髓腹角胶质细胞和运动神经元的反应及其相互关系。方法：用免疫组织化学技术、HE染色和Tunnel法，观察坐骨神经切断后1，6，12，24h及3，7和14d腰脊髓腹角胶质原纤维酸性蛋白(GFAP)标记的星形胶质细胞、OX-42标记的小胶质细胞及运动神经元的变化。结果：坐骨神经切断侧腰脊髓腹角可见星形胶质细胞和小胶质细胞活化，星形胶质细胞的活化早于小胶质细胞；后期运动神经元发生凋亡，HE染色显示凋亡细胞周围为反应性OX-42阳性小胶质细胞和GFAP阳性星形胶质细胞包绕。结论：研究结果提示，坐骨神经切断后切断侧腰脊髓腹角活化的胶质细胞与凋亡的运动神经元之间关系密切。     

趋化因子MCP-1、MIP-1α在EAE小鼠脊髓中的表达

目的:研究单核细胞趋化蛋白(MCP)-1和巨噬细胞炎性蛋白(MIP)-1α与实验性自身免疫性脑脊髓炎(EAE)发病的关系。方法:用髓鞘少突胶质细胞糖蛋白_(35-55)多肽加福氏完全佐剂皮下注射免疫C57BL/6小鼠建立EAE模型,用免疫组织化学方法观察EAE小鼠发病后第0天(初期)、第7天(高峰期)及第30天(恢复期)脊髓中MCP-1、MIP-1α的表达的变化,并通过免疫组化染色标记星形胶质细胞及小胶质细胞,判断MCP-1、MIP-1α的细胞来源。结果: MCP-1、MIP-1α在EAE小鼠发病初期脊髓中有少量表达,发病高峰期表达增高,而恢复期无表达,MCP-1主要由星形胶质细胞产生,MIP-1α主要由小胶质细胞产生;对照组小鼠脊髓中则没有MCP-1、MIP-1α表达。结论:趋化因子MCP-1、MIP-1α在EAE小鼠CNS不同胶质细胞中表达,是EAE发病早期募集免疫反应细胞向CNS浸润的重要致炎性因子。     

Wistar大鼠实验性自身免疫性脑脊髓炎胶质纤维酸性蛋白变化的研究

目的通过建立实验性自身免疫性脑脊髓炎(EAE)模型研究Wistar大鼠脑内神经脱髓鞘后星形胶质细胞损伤随时间变化的规律。方法对Wistar大鼠经足垫注射豚鼠脊髓匀浆制作EAE模型,并于不同时间点将其处死,取脑组织进行免疫组化染色及图像分析检测脑组织中胶质纤维酸性蛋白(GFAP)水平并与健康对照组进行比较。结果GFAP阳性细胞随损伤时间呈先上升后下降的变化趋势,于发病后第7天表达最高,第21天恢复正常。其中发病后第7、14天GFAP阳性细胞突起增长、增粗,染色加深。结论EAE模型中星形胶质细胞可能参与了脑组织损伤后的修复过程,其标志性蛋白GFAP水平随损伤时间呈规律性改变。     

光基因技术选择性调控星形胶质细胞对其活化增殖的影响

目的 探讨光敏感通道蛋白Channelrhodopsin2(ChR2)选择性调控星形胶质细胞对其活化增殖的影响。方法 离体培养SD大鼠乳鼠皮层星形胶质细胞,采用慢病毒载体Lenti-GFAP-ChR2-YFP感染星形胶质细胞后以470 nm波长的蓝光特定模式进行光刺激激活ChR2通道,观察在光刺激0、3、6、12、24 h后星形胶质细胞细胞周期的变化。结果 成功将光敏感通道蛋白ChR2表达在星形胶质细胞中; 经光刺激3、6、12、24 h后星形胶质细胞均表现出S期细胞比例增加,且以12及24 h较为显著。结论 激活光敏感通道ChR2可促进星形胶质细胞增殖; 光基因技术可运用于星形胶质细胞活化增殖的研究,它时空精准的特性使星形胶质细胞作为神经系统疾病治疗靶点具有更高的应用前景     

人脐血干细胞移植治疗实验性自身免疫性脑脊髓炎的研究

目的研究人脐血干细胞(HUCBCs)移植治疗实验性自身免疫性脑脊髓炎(EAE)的效果以及HUCBCs在EAE大鼠脑和脊髓的状况。方法从新生儿脐带血分离出单个核细胞,体外培养并予5-溴脱氧嘧啶尿苷(Brdu)标记48h。用豚鼠全脊髓匀浆免疫Wistar大鼠制备EAE模型。在免疫后14d将3&#215;106HUCBCs经尾静脉注射移植入EAE大鼠(移植组)体内,观察大鼠移植后不同时间的神经功能缺损评分、脑和脊髓脱髓鞘病灶数的变化;用免疫组化技术观察移植后的HUCBCs在EAE大鼠脑和脊髓内存活、迁徙、分化的状况,并与对照组比较。结果移植组大鼠移植后21d、28d的神经功能缺损评分显著低于对照组(均P&lt;0.05);移植后7d、14d、21d、28d脑和脊髓中均可见Brdu染色阳性细胞,移植后21d、28d明显多于移植后7d、14d(均P&lt;0.05);植入的HUCBCs在大鼠脑和脊髓内能向损伤区域迁徙并能分化为星形胶质细胞、少突胶质细胞和神经元。移植后14d、21d、28d脑和脊髓内脱髓鞘病灶数明显少于对照组(均P&lt;0.05)。结论HUCBCs移植能显著改善EAE大鼠的神经功能,并能在其脑和脊髓内存活、迁徙和分化,减少脱髓鞘...     

小胶质细胞活化在实验性自身免疫性脑脊髓炎中的作用机制

目的探讨小胶质细胞活化在实验性自身免疫性脑脊髓炎(EAE)发病机制中的作用。方法利用同种脑脊髓匀浆诱导EAE模型。采用免疫组化法、免疫组织荧光染色观察小胶质细胞对EAE不同病期炎性脱髓鞘病灶的反应,采用免疫组化法、ELISA法观察脑组织及外周血肿瘤坏死因子α(TNF-α)的表达。结果EAE发病前小胶质细胞即开始激活并持续至高峰期,形态学上表现为从正常的细小分枝状逐渐演变为高度分枝状、阿米巴状。免疫组化染色显示TNF-α阳性细胞多为小胶质细胞。EAE大鼠发病前脑组织中小胶质细胞、TNF-α阳性细胞数及外周血TNF-α水平已升高并持续至高峰期。结论小胶质细胞活化伴随EAE发病的整个过程。活化后的小胶质细胞可能通过合成和释放多种炎症介导物及细胞因子如TNF-α,进一步扩大炎症反应,进而促使髓鞘病变。     

大鼠脑缺血再灌注后神经细胞的细胞周期特征的比较研究

目的比较观察大鼠局灶性脑缺血后星形胶质细胞和神经元细胞周期的变化特征。方法采用线栓法大鼠大脑中动脉栓塞模型,利用流式细胞技术检测假手术组和缺血再灌注后不同时间点各组大脑皮层和海马中星形胶质细胞和神经元细胞周期的异常激活和动态变化。结果缺血后大脑皮层中神经元24h时即发生明显细胞周期变化,而3d时进入细胞周期的星形胶质细胞才明显增加;海马中星形胶质细胞却先于神经元进入细胞周期,于24h时细胞周期即发生明显变化,与假手术组比较有显著差异(P<0.01)。结论在不同脑区星形胶质细胞和神经元两者对缺血性脑损伤的敏感性互不相同,并且不同脑区的星形胶质细胞对缺血性脑损伤的敏感性也有不同,脑缺血后2种细胞均出现细胞周期的异常激活。     

Gliosis in the spinal cords of rats with experimental allergic encephalomyelitis: immunostaining of carbonic anhydrase and vimentin in reactive astrocytes

Spinal cord sections from rats sensitized to develop experimental allergic encephalomyelitis (EAE) were immunostained with antibodies against glial fibrillary acidic protein (GFAP), carbonic anhydrase, and vimentin, to see whether the latter two antigens could be detected in GFAP-positive reactive astrocytes. Sixteen days after sensitization (16 dpi) there was intense carbonic anhydrase immunostaining in GFAP-positive cells in the spinal cords of EAE rats, particularly in the white matter. At 13 and 20 dpi carbonic anhydrase immunostaining in astrocytes was less intense, and in the spinal cord white matter of control animals carbonic anhydrase was not detected in the few GFAP-positive cells. In the spinal cords of EAE rats vimentin immunostaining was observed in inflammatory cells and astrocytes. In the latter, GFAP and carbonic anhydrase were colocalized with vimentin. The data suggest that carbonic anhydrase expression in astrocytes is an acute response to injury and that vimentin can be detected in astrocytes, as well as inflammatory cells, as early as 16 dpi.     

GFAP mRNA fluctuates in synchrony with chronic relapsing EAE symptoms in SJL/J mice

Activation of astrocytes and hypertrophy of their processes is a result of a number of pathological conditions in the central nervous system. Astrocytic gliosis is especially prominent in multiple sclerosis (MS), where astrocytic fibers form a dense matrix around demyelinated axons. Experimental allergic encephalomyelitis (EAE), a laboratory model for MS, is also accompanied by astrocytic hyperactivity. We have previously shown the formation of plaque-like structures which stain heavily for glial fibrillary acidic protein (GFAP) in the brains and spinal cords of SJL/J mice after several episodes of chronic relapsing EAE (Smith and Eng: J Neurosci Res 18:203, 1987). To further investigate the mechanisms of this phenomenon, we have measured the levels of mRNA for GFAP throughout the course of three episodes and recoveries of EAE in the SJL/J mouse. Mice were immunized with spinal cord homogenate and subsequently developed EAE. After recovery they were again immunized at appropriate intervals, resulting in successive episodes of EAE, with partial or complete recovery between the paralytic stages. At appropriate times in the course of the different stages of EAE, spinal cords were dissected and RNA was prepared from each spinal cord. RNA Was analyzed by Northern blots to determine the levels of mRNA for GFAP and, as a control, for the 70 kDa neurofilament (NF-L). With the onset of the first EAE episode GFAP mRNA in spinal cords from animals with mild symptoms increased to sixfold the control level (P < 0.02) and to 20-fold in those with paralysis (P < 0.01). With recovery, the GFAP mRNA level decreased to twice the control. With each subsequent episodes, a chronic but stable neurological deficit was established, with GFAP mRNA at about eightfold the control levels (P < 0.01). Over the course of several episodes, the GFAP rose to about 2.8 times the control, while vimentin increased by a factor of 3.6. Thus multiple episodes of EAE resulted in upregulation of GFAP mRNA and accumulation of GFAP, which are associated with astrocyte activation and hypertrophy. Similar events may occur in the human demyelinative disease MS, where multiple episodes of inflammatory cell invasion occur, resulting in a neurological deficit. © 1995 Wiley-Liss, Inc.     

实验性自身免疫性脑脊髓炎的小胶质细胞和星形胶质细胞反应

目的确定小胶质细胞和星形胶质细胞在实验性自身免疫性脑脊髓炎（ＥＡＥ）发病及病变发展中的作用。方法用牛脊髓髓鞘碱性蛋白（ＭＢＰ）免疫豚鼠发生ＥＡＥ,用免疫组化法观察ＥＡＥ不同病期小胶质细胞和星形胶质细胞对炎性脱髓鞘病灶的反应。结果发生ＥＡＥ的前３天,小胶质细胞即开始激活,在临床症状出现时其数量及激活程度达高峰,并持续至高峰期。恢复期数量逐渐减少,激活程度逐渐减弱。星形胶质细胞在症状高峰期开始激活并围绕在浸润细胞和病变血管周围,似有隔离小胶质细胞与病灶接触的作用,至恢复期激活明显。结论小胶质细胞激活在ＥＡＥ的发病及进展中起重要作用,而星形胶质细胞主要与疾病的恢复有关。     

Microglial and astroglial reactions to inflammatory lesions of experimental autoimmune encephalomyelitis in the rat central nervous system

Gliosis is a repair process of lesions appearing in the central nervous system (CNS). Although gliosis by astrocytes (astrocytic gliosis) has been well documented, that by microglia (microglial gliosis) remains poorly understood. In the present study we induced experimental autoimmune encephalomyelitis (EAE) in Lewis rats and examined microglial and astroglial reactions to EAE lesions at various stages of the disease by immunohistochemistry. For the demonstration of microglia and astrocytes, antibodies against complement receptor type 3 (OX42) and glial fibrillary acidic protein (GFAP) were used, respectively. It was revealed that the whole course of microglial and astroglial reactions to EAE lesions is divisible into three stages, i.e., initial, peak and recovery stages. Microglial and astroglial reactions to EAE lesions at each stage correspond well with the clinical and histological stages of EAE. At the initial stage, rats showed mild clinical signs and a few inflammatory foci were found in the CNS. Microglia were increased in number in close association with inflammatory cell aggregates, whereas astrocytes showed no significant reaction in spite of the presence of inflammatory cells. At the peak stage, rats showed full-blown EAE and the number of inflammatory cells reached maximum. The most characteristic finding at this stage was 'encasement' of inflammatory lesions by astrocytic fibers. Microglia were increased in number, but association of microglia with lesions was prevented by astrocytes. Interestingly, however, such characteristic distribution of microglia and astrocytes was not observed at the recovery stage. Residual inflammatory cell aggregates were intermingled with dense microglial and astrocytic gliosis, forming 'micro-astroglial scars'. Double immunofluorescence staining with anti-GFAP and anti-bromodeoxyuridine (BrdU), or with OX42 and anti-BrdU revealed that BrdU-incorporated microglia, but not astrocytes, were present mainly at the initial and peak stages, suggesting that microglia would proliferate by cell division to create gliosis, whereas astrocytic gliosis would be a result of migration of astrocytes and/or up-regulation of expression of GFAP molecule. Taken together with previous in vitro findings that microglia, but not astrocytes, stimulate encephalitogenic T cell proliferation, these in vivo findings suggest that microglia augment, whereas astrocytes suppress, inflammatory processes in the CNS.     

Expression of citrullinated proteins in murine experimental autoimmune encephalomyelitis

In this study, we demonstrate for the first time the immunohistochemical expression of citrullinated proteins in the central nervous system (CNS) of mice with myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE). By using an established monoclonal antibody (F95) against natural and synthetic citrullinated proteins (Nicholas and Whitaker [2002] Glia 37:328-336), numerous, small, previously unrecognized "patches" of citrullinated proteins were discovered throughout EAE brains, whereas EAE spinal cords showed similar but much larger lesions. On dual color immunofluorescence, these lesions were found to contain citrullinated myelin basic protein (MBP) and were surrounded by astrocytes immunoreactive for both glial fibrillary acidic protein (GFAP) and F95. These lesions became evident about the time when EAE mice became symptomatic and increased in size and number with increasing disease severity. In some sections of spinal cord but not brains of severely debilitated EAE mice, a widespread gliotic response was seen, with astrocytes containing citrullinated GFAP spread throughout the gray and white matter. Western blot analysis of acidic proteins from the brains and spinal cords of EAE mice had higher levels of multiple citrullinated GFAP isoforms compared with controls, with more F95-positive bands in the EAE brains vs. spinal cords. These results raise the possibility that citrullination of both GFAP and MBP may contribute to the pathophysiology of EAE and that the brains of EAE mice may contain more pathology than previously realized.     

Expression of caveolin-1, -2, and -3 in the spinal cords of Lewis rats with experimental autoimmune encephalomyelitis

The expression of caveolin-1, -2, and -3 in the spinal cords of Lewis rats with experimental autoimmune encephalomyelitis (EAE) was analyzed. Western blot analysis showed that three isotypes of caveolins including caveolin-1, -2 and -3 increased significantly in the spinal cords of rats during the early stage of EAE, as compared with the levels in control animals (p<0.05); the elevated level of each caveolin persisted during the peak and recovery stage of EAE. Immunohistochemistry demonstrated that caveolin-1 and -2 were expressed constitutively in the vascular endothelial cells and ependymal cells of the normal rat spinal cord, whereas caveolin-3 was almost exclusively localized in astrocytes. In EAE lesions, the immunoreactivity of caveolin-1 was increased in the ependymal cells, some astrocytes, and some inflammatory cells of the spinal cord, while that of caveolin-2 showed an intense immunoreactivity. Caveolin-3 was expressed constitutively in some astrocytes, but not in endothelial cells; its immunoreactivity was increased in reactive astrocytes in EAE lesions. The results of the Western blot analysis largely confirmed the observations obtained with immunohistochemistry. Taking all the findings into consideration, we postulate that the expression levels of each caveolin begin to increase when EAE is initiated, possibly contributing to the modulation of signal transduction pathways in the affected cells.     

Immunocytochemical staining for glial fibrillary acidic protein and the metabolism of cytoskeletal proteins in experimental allergic encephalomyelitis

Spinal cord sections from Lewis rats with acute experimental allergic encephalomyelitis (EAE) showed greatly increased staining of astrocytes when stained immunocytochemically for glial fibrillary acidicc protein (GFAP). Fibrous processes in white matter were heavily stained early in the course of the disease when paralysis was first evident (10–12 days after injection of guinea pig spinal cord myelin), then protoplasmic astrocytes were stained in the gray matter and became more heavily stained at 20 dats post-injection. The stained astrocytes were evenly distributed throughout the tissue, and did not correspond to the sites of the lesions. Spinal cord slices of control and EAE rats were incubated with [³H]amino acids, then cytoskeletal proteins were prepared in an enriched fraction, separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and the protein bands counted for radioactivity. In the EAE rat all cytoskeletal proteins, including the neurofilaments, vimentin, microtubules, GFAP and actin, showed increased uptake of radioactive amino acids. Immunoprecipitation of GFAP with specific antiserum showed increased radioactivity in the complex beginning at day 10 when cellular infiltration was beginning in the EAE animals. As the disease became acute, the radioactivity in the immunoprecipitated GFAP increased, in some cases to very high levels, then by day 18 when recovery was underway, the radioactivity had fallen to normal levels. Possible agents causing metabolic activation of protein synthesis in EAE animals include stimulating substances elaborated by infiltrating lymphoid scells, and the generalized edema accompanying the demyelinative condition. The activation of GFAP protein staining and metabolism in EAE might serve as a model for the activated growth of astrocyte processes which cause the severe gliosis seen in multiple sclerosis.     

[3H]Thymidine labeling of astrocytes in experimental allergic encephalomyelitis

In acute experimental allergic encephalomyelitis (EAE), astrocytes in spinal cord tissue hypertrophy and stain intensely with antibody to the glial fibrillary acidic protein (GFAP). We attempted to determine if this activation is a result solely of hypertrophy of existing astrocytes or if astrocyte division might also occur. Lewis rats in various stages of acute EAE were injected with [³H]thymidine, the spinal cord sections were prepared, immunostained for GFAP and processed for radioautography. In spinal cords from rats administered thymidine on days 11–15 after sensitization a large number of mononuclear cells showed radioactive label. Many of these labeled cells, most likely monocytes and lymphocytes, were associated with inflammatory lesions, but others were located in the CNS parenchyma at great distances from the lesions. Most cells staining for the GFAP were hypertrophied with greatly extended cell processes, and the nuclei of some of these cells identified as astrocytes were overlaid with silver grains, indicating uptake of [³H]thymidine. In addition a few ependymal cells appeared to be labeled. No GFAP-stained cells from the Freund's adjuvant controls contained radioactive label. Similar studies using SJL/J mice with chronic relapsing EAE yielded very few labeled inflammatory cells or astrocytes. This study indicates that division takes place in some astrocytes in acute EAE, but occurs much less frequently in chronic EAE. Probably most of the increase in GFAP-stained material is a result of hypertrophy of astrocytes rather than of massive cell division.     

[H]Thymidine labeling of astrocytes in experimental allergic encephalomyelitis

In acute experimental allergic encephalomyelitis (EAE), astrocytes in spinal cord tissue hypertrophy and stain intensely with antibody to the glial fibrillary acidic protein (GFAP). We attempted to determine if this activation is a result solely of hypertrophy of existing astrocytes or if astrocyte division might also occur. Lewis rats in various stages of acute EAE were injected with [³H]thymidine, the spinal cord sections were prepared, immunostained for GFAP and processed for radioautography. In spinal cords from rats administered thymidine on days 11–15 after sensitization a large number of mononuclear cells showed radioactive label. Many of these labeled cells, most likely monocytes and lymphocytes, were associated with inflammatory lesions, but others were located in the CNS parenchyma at great distances from the lesions. Most cells staining for the GFAP were hypertrophied with greatly extended cell processes, and the nuclei of some of these cells identified as astrocytes were overlaid with silver grains, indicating uptake of [³H]thymidine. In addition a few ependymal cells appeared to be labeled. No GFAP-stained cells from the Freund's adjuvant controls contained radioactive label. Similar studies using SJL/J mice with chronic relapsing EAE yielded very few labeled inflammatory cells or astrocytes. This study indicates that division takes place in some astrocytes in acute EAE, but occurs much less frequently in chronic EAE. Probably most of the increase in GFAP-stained material is a result of hypertrophy of astrocytes rather than of massive cell division.     

Expression of osteopontin and its ligand, CD44, in the spinal cords of Lewis rats with experimental autoimmune encephalomyelitis

The expression of osteopontin (OPN) and one of its ligands, CD44, was studied in the spinal cord of rats with experimental autoimmune encephalomyelitis (EAE). Western blot analysis showed that osteopontin significantly increased at the early and peak stage of EAE and slightly declined thereafter. Osteopontin was constitutively expressed in some astrocytes adjacent to pia mater and neurons in normal rats, and was shown to be increased in the same cells and also in some inflammatory cells including macrophages at the early and peak stage of EAE. CD44, a ligand for osteopontin, was constitutively expressed in astrocytes in normal and control spinal cords and was also expressed in inflammatory cells, as well as increased expression in astrocytes in EAE. These findings suggest that inflammatory cells as well as reactive astrocytes are major sources of osteopontin in rat EAE, and osteopontin may interact with its ligand CD44 on astrocytes and inflammatory cells in EAE, possibly mediating autoimmune central nervous system (CNS) diseases in rats.