小胶质细胞与NG2胶质细胞相互作用研究进展

小胶质细胞是大脑的固有免疫细胞,在中枢神经系统的发育和稳态中起着重要的作用。NG2胶质细胞被认为是少突胶质细胞的前体细胞。近年来的研究表明,NG2胶质细胞与其他神经胶质细胞也存在广泛的相互作用,参与大脑神经免疫反应。加强对小胶质细胞和NG2胶质细胞之间相互作用的认识将有助于发现大脑中免疫调节的新途径,有利于神经炎症和神经退行性疾病的治疗,本文将对这两种细胞之间的相互作用进行综述。     

NG2与中枢神经系统疾病研究新进展

<正>NG2是一种硫酸软骨素蛋白多糖(chondroitin sulphate peoteoglycan,CSPG),在发育及成熟哺乳动物中枢神经系统中广泛表达。表达NG2的细胞根据其密度、分布、独特的细胞标记和生理性能归为一类独特的神经胶质细胞。NG2细胞具有神经干细胞的部分特性和分化产生不同细胞系的潜     

星形胶质细胞在髓鞘形成与修复中作用的研究进展

星形胶质细胞(AST)是中枢神经系统(CNS)内最主要的胶质细胞类型,为神经元的代谢提供物质支持。中枢神经系统损伤后,星形胶质细胞经过复杂的变化形成反应性星形胶质细胞,反应性星形胶质细胞对中枢神经系统的修复有着支持和抑制的双重作用。随着星形胶质细胞在大脑中作用的深入研究,目前对星形胶质细胞在髓鞘形成与修复中的作用逐渐明确。本文就星形胶质细胞在髓鞘形成与修复中的作用进行综述。     

星形胶质细胞在中枢神经系统炎性疾病中作用的研究进展

星形胶质细胞应对多种中枢神经系统(CNS)损伤并活化为反应性星形胶质细胞,通过神经保护或神经毒性作用影响CNS的组织修复和神经炎性疾病的发生和发展。反应性星形胶质细胞的发生机制主要与其表型转化及下游炎性通路的激活相关。探索反应性星形胶质细胞的特征及其对CNS炎性疾病的调控机制可能为CNS炎性疾病的发病机制提供新见解和潜在干预靶点。     

中枢神经系统中星形胶质细胞作用的研究进展

星形胶质细胞是中枢神经系统中维持生理动态平衡的关键细胞,具有广泛功能,在正常生理和疾病状态中发挥多样的调节作用,包括提供信息传递和代谢支持、调控血脑屏障功能、调控突触形成、建立和维持适当的突触连接、调节神经保护及神经毒性作用等功能,在中枢神经系统的生长,各种生理、病理环境下均发挥重要作用。该文旨在阐明星形胶质细胞在中枢神经系统中的作用,总结其具体的调节过程和相关机制,为神经系统相关疾病的诊断和治疗提供新思路和方向。     

TREM2与脑内小胶质细胞作用对中枢神经系统的影响

小胶质细胞是中枢神经系统中的固有免疫细胞.在生理条件下,小胶质细胞起免疫监视作用,参与突触修饰、清除凋亡细胞.在病理条件下,小胶质细胞由静息状态转化为激活态,向病变部位迁移、增殖,吞噬清除异常物质、分泌细胞因子,参与氧化应激和神经修复.小胶质细胞在众多中枢神经系统疾病中被称为"双刃剑",以阿尔茨海默病(Alzheime...     

小胶质细胞在创伤性脑损伤中作用的研究进展

小胶质细胞(MG)是人体中枢神经系统(CNS)固有的免疫细胞成分,正常情况下处于静止状态,缺乏吞噬功能,仅具有一定的迁移能力和吞饮功能。但作为CNS的第一道防线,可在CNS病变时被激活发挥类似于巨噬细胞的吞噬保护功能;当功能发生紊乱时又会加重病变的发生发展,从而具有修复和损伤的"双刃剑"作用。创伤性脑损伤(TBI)是一个影响社会的重大健康和社会经济问题,包括突然加速或减速的间接损伤、冲击或撞击引起的脑挫伤和爆炸伤等。TBI发生时会激活MG,使其增生与聚集,同时常伴有免疫表型、细胞形态与功能等一系列的变化。本文旨在针对MG参与TBI病理生理过程进行综述。     

Neuregulins 1对中枢神经系统胶质细胞的作用

Neuregulins(NRGs)是一类作用于ErbB受体酪氨酸激酶家族的细胞-细胞间信号转导蛋白,有4个不同的基因编码。Neuregulin(NRG)的命名最早是由Mark Marchionni提出的,它代表了早期对神经系统中这类重要因子命名以及认识的总结[1-2]。NRG1对于心脏、乳腺,尤其是神经系统的发育起着极为重要的作用。虽然NRG1最初被认为是胶质细胞的有丝分裂原,但现在已经公认NRG1对于神经细胞及非神经细胞的存活、迁移和分化均起重要作用。有关NRG1对于周围神经系统发育的作用明确已久。NRG1能使神经嵴细胞定向分化为雪旺细胞,能促进雪旺细胞前体细胞的…     

小胶质细胞在中枢神经系统和胶质瘤中的免疫学作用及其相关研究进展

血脑屏障在正常情况下能够保证脑的内环境的高度稳定性,以利于中枢神经系统的机能活动。中枢神经系统内缺乏各种常见的抗原递呈细胞,但小胶质细胞可作为潜在的抗原递呈细胞将MHC分子结合的抗原肽与T细胞受体结合介导相应的免疫反应。而在胶质瘤组织中高度浸润的小胶质细胞可通过对肿瘤微环境的免疫抑制而促进肿瘤生长。一旦小胶质细胞被激活就能成为强大的免疫效应细胞,在中枢神经系统损伤和疾病中发挥多种生物学功能。     

小胶质细胞在中枢神经系统和胶质瘤中的免疫学作用及其相关研究进展

血脑屏障在正常情况下能够保证脑的内环境的高度稳定性,以利于中枢神经系统的机能活动.中枢神经系统内缺乏各种常见的抗原递呈细胞,但小胶质细胞可作为潜在的抗原递呈细胞将MHC分子结合的抗原肽与T细胞受体结合介导相应的免疫反应.而在胶质瘤组织中高度浸润的小胶质细胞可通过对肿瘤微环境的免疫抑制而促进肿瘤生长.一旦小胶质细胞被激活就能成为强大的免疫效应细胞,在中枢神经系统损伤和疾病中发挥多种生物学功能.     

硫酸软骨素蛋白多糖4细胞在成年大鼠中枢神经系统的定位分布及其异质性

目的:研究硫酸软骨素蛋白多糖4细胞(NG2细胞)在成年大鼠大脑与脊髓的定位分布及其异质性.方法:应用免疫组织化学、免疫荧光方法观察大脑与脊髓NG2阳性细胞分布及其形态特征.采用Image Pro Plus6.0图像分析软件对NG2阳性细胞胞体面积、突起个数、突起长度进行测量.应用SPSS17.0软件对结果进行统计学分析.结果:NG2细胞在成年大鼠中枢神经系统内广泛分布;在脑内NG2细胞突起数目较多,胞体较小;而在脊髓内NG2细胞突起较少,但其胞体却较大.结论:在脑和脊髓内NG2细胞的形态存在异质性,提示其在成年大鼠中枢神经系统两个部位具有不同的功能.     

NG2-expressing cells as oligodendrocyte progenitors in the normal and demyelinated adult central nervous system

The mammalian adult central nervous system (CNS) is known to respond rapidly to demyelinating insults by regenerating oligodendrocytes for remyelination from a dividing precursor population. A widespread population of cells exists within the adult CNS that is thought to belong to the oligodendrocyte lineage, but which do not express proteins characteristic of mature myelinating oligodendrocytes, such as myelin basic protein (MBP) and 2,3-cyclic nucleotide 3-phosphodiesterase (CNP). Instead, these cells have phenotypic characteristics of a more immature stage of the oligodendrocyte lineage. They express the NG2 chondroitin sulphate proteoglycan, in addition to O4 and the platelet-derived growth factor alpha-receptor, all widely accepted as markers for oligodendrocyte progenitor cells (OPCs) throughout development. However, NG2+ cells residing in the adult CNS do not resemble embryonic or neonatal NG2+ cells in terms of their morphology or proliferation characteristics, but instead represent a unique type of glial cell that has the ability to react rapidly to CNS damage. In this review, we present the evidence that adult NG2+ cells are part of the oligodendrocyte lineage and are capable of giving rise to new oligodendrocytes under both normal and demyelinating conditions. We also review the literature that these cells may have multiple functional roles within the adult CNS, notwithstanding their primary role as OPCs.     

NG2 and Olig2 expression provides evidence for phenotypic deregulation of cultured central nervous system and peripheral nervous system neural precursor cells

Neural stem cells cultured with fibroblast growth factor 2 (FGF2)/epidermal growth factor (EGF) generate clonal expansions called neurospheres (NS), which are widely used for therapy in animal models. However, their cellular composition is still poorly defined. Here, we report that NS derived from several embryonic and adult central nervous system (CNS) regions are composed mainly of remarkable cells coexpressing radial glia markers (BLBP, RC2, GLAST), oligodendrogenic/neurogenic factors (Mash1, Olig2, Nkx2.2), and markers that in vivo are typical of the oligodendrocyte lineage (NG2, A2B5, PDGFR-alpha). On NS differentiation, the latter remain mostly expressed in neurons, together with Olig2 and Mash1. Using cytometry, we show that in growing NS the small population of multipotential self-renewing NS-forming cells are A2B5(+) and NG2(+). Additionally, we demonstrate that these NS-forming cells in the embryonic spinal cord were initially NG2(-) and rapidly acquired NG2 in vitro. NG2 and Olig2 were found to be rapidly induced by cell culture conditions in spinal cord neural precursor cells. Olig2 expression was also induced in astrocytes and embryonic peripheral nervous system (PNS) cells in culture after EGF/FGF treatment. These data provide new evidence for profound phenotypic modifications in CNS and PNS neural precursor cells induced by culture conditions.     

Physiological characteristics of NG2-expressing glial cells

Antibodies against the chondroitin sulfate proteoglycan NG2 label a subpopulation of glial cells within the CNS, which have a small cell body and thin radiating processes. Physiological recordings from these small cells in acute brain slices have revealed that they possess unique properties, suggesting that they may comprise a class of glial cells distinct from astrocytes, oligodendrocytes, or microglia. NG2-expressing glial cells (abbreviated as NG2 cells here) have a moderate input resistance and are not dye- or tracer-coupled to adjacent cells. They express voltage-gated Na⁺, K⁺and Ca²⁺conductances, though they do not exhibit regenerative Na⁺or Ca²⁺action potentials due to the much larger K⁺conductances present. In addition to voltage-gated conductances, they express receptors for various neurotransmitters. In the hippocampus, AMPA and GABA_Areceptors on these cells are activated by release of transmitter from neurons at defined synaptic junctions that are formed with CA3 pyramidal neurons and GABAergic interneurons. These rapid forms of neuron-glial communication may regulate the proliferation rate of NG2 cells or their development into mature oligodendrocytes. These depolarizing inputs may also trigger the release of neuroactive substances from NG2 cells, providing feedback regulation of signaling at neuronal synapses. Although the presence of Ca²⁺permeable AMPA receptors provides a pathway to link neuronal activity to Ca²⁺dependent processes within the NG2 cells, these receptors also put these cells at risk for glutamate-associated excitotoxicity. This vulnerability to the sustained elevation of glutamate may underlie ischemic induced damage to white matter tracts and contribute to cerebral palsy in premature infants.     

周细胞在中枢神经系统中作用的研究进展

周细胞(pericyte)是位于血管内皮与基膜间的一种多功能细胞。目前认为周细胞对血管生成、免疫调节及多种组织器官的成熟和稳定均有重要意义。研究证实,周细胞在脑血管病、神经退行性疾病、脑损伤及脑肿瘤等多种神经系统疾病的发生发展中也具有重要作用。本文结合最新研究,对周细胞在中枢神经系统中的作用进行综述,以期为深入探明周细胞的作用机制及发现新的治疗靶向提供线索。     

Nestin in central nervous system cells

This literature review reflects current knowledge on the intermediate filament protein nestin, which most authors regard as a marker of “neural stem/progenitor cells.” The structural-functional characteristics of nestin and its presence in various central nervous system cells at different stages of ontogenesis in normal and pathological conditions are discussed. __________ Translated from Morfologiya, Vol. 131, No. 1, pp. 85–90, January–February, 2007. Director: Corresponding Member of the Russian Academy of Medical Sciences Professor V. A. Otellin     

Lipocortin-1 immunoreactivity in central and peripheral nervous system glial tumors

We examined the cellular distribution of lipocortin-1 (L-1), a major physiologic substrate for the epidermal growth factor receptor/kinase, in 122 central nervous system (CNS) and peripheral nervous system (PNS) neoplasms using the peroxidase-antiperoxidase technique with a polyclonal antibody specific for L-1. Extensive L-1 immunoreactivity was demonstrated in many CNS tumors; in 11 of 21 glioblastoma multiformes, in five of 12 anaplastic astrocytomas, and in five of 14 astrocytomas. Significant numbers of immunoreactive ependymocytes or astrocytes were also seen in six of 13 ependymomas. In contrast, no immunostaining was detected in the oligodendrocytes in any of ten oligodendrogliomas. PNS tumors, found in two of five malignant nerve sheath tumors, 13 of 15 schwannomas, 13 of 17 neurofibromas, and 14 of 15 traumatic neuromas, also contained considerable L-1 immunoreactivity in Schwann cells or mast cells. These findings raise the possibility that L-1 may participate in the proliferation or subsequent differentiation of neoplastic astrocytes, ependymocytes, and Schwann cells.