大鼠骨髓源性神经干细胞移植治疗颞叶癫痫实验研究

目的 探讨骨髓源性神经干细胞移植至KA大鼠海马后与宿主细胞的整合及其对损伤宿主的修复作用,从而为干细胞移植治疗颞叶癫痫提供理论依据.方法 首先分离大鼠骨髓基质细胞,并在特定的条件下培养使其诱导分化为神经干细胞,且使用Feridex对干细胞进行标记.然后建立大鼠颞叶癫痫模型,将Feridex标记的神经干细胞自体移植至KA大鼠的海马内,观察移植后1周、2周、4周、8周和16周大鼠海马的脑电图、病理学和MRI改变情况.结果 与KA未移植组相比,移植组大鼠海马脑电图的波幅明显降低,最高降低达40%以上;KA移植组海马CA3区锥体细胞数与未移植组相比有极显著性差异（P＜0.01）;KA移植组海马损伤侧的Timm染色与未移植组相比也有极显著性差异（P＜0.01）;MRI检查发现在神经干细胞移植后1周和2周时低信号改变区比较局限,但移植4周、8周和16周后低信号改变明显增大,且随着时间的推移低信号改变区逐渐增大.结论 骨髓源性神经干细胞移植至KA大鼠后能与宿主细胞进行整合,且对宿主海马具有显著的修复作用,但其具体的作用机制尚待进一步研究.     

海马干细胞移植对癫癎鼠脑电影响的初步研究

目的研究神经干细胞移植对癫癎鼠脑电的影响,为神经干细胞移植治疗癫癎提供理论依据.方法分离、培养新生鼠海马干细胞,将其移植至海人酸(KA)所致癫癎模型鼠的右侧海马,比较移植组及未移植组大鼠在移植前和移植后1周、4周、8周及24周海马及杏仁核的脑电变化.结果海马干细胞移植可减少癫癎动物脑电的痫性发放,并降低癫癎波幅约50%.结论神经干细胞移植对于KA诱发癫癎鼠的癫癎具有一定的抑制作用,但其具体作用机制还有待于进一步的研究.     

辛醇预处理对红藻氨酸诱导的癫(癎)大鼠海马神经元凋亡和胶质纤维酸性蛋白表达的影响

目的 观察缝隙连接阻断剂辛醇预处理对红藻氨酸(KA)诱导的癫(癎)大鼠海马神经元凋亡和胶质纤维酸性蛋白(GFAP)表达的影响.方法 160只雄性SD大鼠随机分为KA组、辛醇组、生理盐水(NS)组和二甲基亚砜(DMSO)组,应用KA右侧杏仁核注射制作癫(癎)大鼠模型;制模前30 min辛醇组腹腔注射辛醇溶液;制模后3h、6h、12 h、24 h和7d应用原位末端标记(TUNEL)法和免疫组化染色法分别检测各组大鼠海马CA3区TUNEL和GFAP阳性细胞数.结果 KA组制模后6h海马CA3区有TUNEL阳性细胞表达,并逐渐增多,7d达高峰;辛醇组制模后在6 h～7 d TUNEL阳性细胞数明显少于KA组(均P＜0.01);KA组海马CA3区GFAP阳性细胞数随时间而逐渐增多,各时间点明显多于辛醇组(均P＜0.01).结论 辛醇神经保护作用的机制可能与抑制细胞缝隙连接间通讯,切断凋亡信号传播,以减少神经元凋亡有关.     

发育期癫大鼠移植骨髓源性神经干细胞对海马BDNF和bFGF表达的影响

目的将骨髓源性神经干细胞(BMSCs)移植到发育期癫大鼠海马区,观察大鼠海马脑源性神经营养因子(BDNF)和碱性成纤维生长因子(bFGF)表达的变化。方法选择21日龄发育期大鼠,分离大鼠骨髓基质细胞,在特定条件下培养使其诱导分化为神经干细胞(NSC)。建立戊四氮(PTZ)点燃癫大鼠模型,将BMSCs经侧脑室注射移植至癫大鼠海马区;侧脑室注射磷酸缓冲液(PBS)作为对照。分为4组(均n=8):对照组(无癫发作),PTZ致组(癫造模,无治疗),假手术组(癫+PBS侧脑室注射),治疗组(癫+NSC侧脑室注射)。于3、7和14 d处理后用免疫组化法检测大鼠海马区BDNF和bFGF表达。结果致组大鼠海马区(齿状回、CA1区)BDNF和bFGF表达较对照组增加(P0.05),治疗组海马区(齿状回、CA1区)BDNF和bFGF表达较假手术组也有所增加(P0.05)。结论 BMSCs移植可以增加PTZ致大鼠海马BDNF和bFGF表达,从而发挥对癫后脑损伤的保护作用。     

Orexin受体拮抗剂对睡眠剥夺的戊四氮致(癎)大鼠癫(癎)发作及脑组织病理学变化的影响

目的 探讨orexin-1受体(OX1R)和orexin-2受体(OX2R)拮抗剂对睡眠剥夺(SD)的戊四氮(PTZ)致(癎)大鼠癫(癎)发作及脑组织病理学变化的影响.方法 雄性Wistar大鼠48只,随机分为正常对照(NC)组、PTZ组、SD+ PTZ( SD)组、SD+ PTZ+二甲基亚砜(DMSO)组、SD+ PTZ+ OX1R拮抗剂SB334867(SB)组和SD+ PTZ+ OX2R拮抗剂TCS OX229 (TCS)组.采用改良多平台SD法,SD前及SD 48 h分别给予相应组大鼠侧脑室注射DMSO、SB或TCS.SD 72 h给予各组腹腔注射PTZ 50 mg/kg诱导癫(癎)发作;观察各组大鼠癫(癎)发作的潜伏期、发作等级评分、发作持续时间及死亡率;应用常规染色法观察海马的病理学变化,免疫荧光法(BrdU标记)观察神经细胞增殖的变化.结果 (1)与PTZ组比较,SD组及DMSO组(癎)性发作的潜伏期明显缩短,发作等级评分、持续时间及死亡率明显增加(均P ＜0.001),海马CA3区神经元损害加重,海马齿状回门区和颗粒细胞下层BrdU阳性细胞数显著增多(P＜0.001);SD组与DMSO组间差异无统计学意义.(2)与SD组比较,SB组和TCS组大鼠(癎)性发作的潜伏期明显延长,发作等级评分、持续时间及死亡率明显下降(均P＜0.05),海马CA3区神经元损害明显减轻,齿状回门区和颗粒下层BrdU阳性细胞数减少(均P ＜0.05);TCS组的变化较SB组更显著(P＜0.05 ～0.01).结论 Orexin受体拮抗剂尤其是OX2R拮抗剂可通过减轻海马CA3区神经元的损害和抑制齿状回区细胞增殖减轻SD对PTZ诱导癫(癎)发作的不利影响.     

骨髓源性神经干细胞自体移植海藻酸致痫大鼠海马后脑电图的改变

目的探讨骨髓源性神经干细胞移植至海藻酸（KA）致痫大鼠海马后对宿主海马脑电图的影响，从而为神经干细胞移植治疗颞叶癫痫提供理论依据。方法无菌条件下分离大鼠骨髓基质细胞，在特定的条件下培养使其诱导分化为神经干细胞。建立大鼠颞叶癫痫模型，将诱导分化的神经干细胞自体移植至KA大鼠的右侧海马内，观察移植后1周、2周、4周、8周和16周大鼠海马的MRI和脑电图改变情况。结果MRI检查发现在神经干细胞移植后1周和2周时低信号改变区比较局限，但移植4周、8周和16周后低信号改变明显增大，且随着时间的推移低信号改变区逐渐增大。与未移植组相比，移植组大鼠海马脑电图的波幅明显降低，且随着时间的推移降低幅度也明显增加，最高至移植8周后脑电图波幅降低达40％以上。结论骨髓源性神经干细胞自体移植至KA大鼠后对宿主海马的癫痫样放电有一定的抑制作用。     

颞叶癫大鼠海马轴突导向分子Sema3F及其受体Np2表达的变化

目的 研究颞叶癫(癎)大鼠海马轴突导向分子Sema3F及其受体Np2表达的变化.方法 给SD大鼠腹腔注射匹罗卡品、氯化锂制作颞叶癫(癎)模型.用免疫组化法和原位杂交技术对致(癎)后不同时间点大鼠海马CA1区、CA3区、齿状回的Sema3F mRNA、Np2 mRNA和蛋白表达进行检测,并与正常对照组比较.结果 颞叶癫(癎)大鼠致(癎)后7 d、15 d,海马CA1区、CA3区Sema3F mRNA、Np2 mRNA和蛋白的表达明显低于正常对照组(P＜0.05～0.01), 致(癎)后30 d、60 d表达与正常对照组差异无统计学意义;而齿状回Sema3F mRNA、Np2 mRNA和蛋白的表达与正常对照组的差异无统计学意义.结论 颞叶癫(癎)大鼠海马CA1区、CA3区Sema3F、Np2表达在致(癎)后早期明显下调,而在慢性期恢复正常.     

颞叶癫癎大鼠海马TrkB mRNA及其蛋白表达的动态变化

目的探讨颞叶癫瘸发作大鼠海马TrkB mRNA及其蛋白表达的动态变化特征.方法建立匹罗卡品(PILO)颞叶癫癎大鼠模型,应用原位杂交及免疫组织化学方法分别检测致瘸大鼠海马齿状回、CA3区及CAi区TrkB mRNA及其蛋白质表达的变化.结果 PILO致瘸后3～6 h,海马齿状回颗粒细胞层、CA1、CA3区锥体细胞层TrkBmRNA表达显著增高(P＜0.01),稍后TrkB蛋白表达也随之增高.第7～30d,TrkBmRNA及其蛋白在齿状回、CA3区呈现第二次表达增强.结论在癫癎发作早期,TrkB表达增强,提示其可能参与急性癜癎状态的发生;后期表达增强则可能参与了海马的可塑性反应而与慢性自发性发作形成有关.     

核因子-κB活性抑制剂对癫(癎)大鼠的脑保护作用

目的 研究核因子-κB(NF-κB)活性抑制剂吡咯烷二硫代氨基甲酸盐(PDTC)对癫(癎)大鼠的脑保护作用.方法 将36只雄性SD大鼠随机分为癫(癎)组(14只)、PDTC干预组(PDTC组,14只)和假手术组(8只).采用海马注射海人酸(KA)方法制作癫(癎)大鼠模型,PDTC组大鼠造模前30 min给于腹腔注射PDTC150 mg,/kg;观察各组大鼠癫(癎)发作的潜伏期和初次至第6次≥Ⅳ级发作的时间(发作严重程度).应用HE染色和免疫组织化学染色,观察各组大鼠海马CA3区残存神经元数和NF-κB的表达.结果 PDTC组大鼠癫(癎)发作潜伏期[(89.6±39.3)min]长于癫(癎)组[(67.5±22.9)min],但差异无统计学意义;PDTC组初次至第6次≥Ⅳ级发作的时间[(29.2±20.4)min]较癫(癎)组[(12.1±4.0)min]显著延长(P＜0.05);与癫(癎)组相比,PDTC组大鼠海马CA3区残存神经元数显著增多(P＜0.05),NF-κB表达水平显著降低(P＜0.01),二者间呈负相关(r=-0.562,P=0.001).结论 NF-κB活性抑制剂能降低癫(癎)发作严重程度,减少海马神经元的变性死亡,具有脑保护作用.提示癫(癎)发作所致脑组织损伤可能与NF-κB活化有关.     

人骨髓间充质干细胞移植老年性痴呆大鼠认知能力和海马超微结构的变化

背景：因发病机制不明,目前尚无治愈老年性痴呆的有效方法。现临床上主要是采用药物治疗,而骨髓间充质干细胞的替代治疗尚处于基础研究阶段,其海马移植后对老年性痴呆认知能力的影响未见报道。 目的：探讨人骨髓间充质干细胞移植对老年性痴呆大鼠认知能力和海马超微结构的影响。 方法：老年雄性Wistar大鼠30只,制备自然衰老痴呆模型,造模后随机分为3组,选取双侧海马为移植区,分化细胞移植组注射定向神经细胞诱导分化的人骨髓间充质干细胞悬液4 μL(2×105个细胞),干细胞移植组注射等量常规培养的人骨髓间充质干细胞,模型组注射等量生理盐水。通过Y迷宫试验测定大鼠的学习、记忆能力,透射电镜观察海马区超微结构。 结果与结论：与移植前大鼠学习、记忆分数比较,移植后12周模型组均显著下降(P < 0.01),干细胞移植组均有所提高(P > 0.05),分化细胞移植组均显著提高(P < 0.01)。移植后12周与模型组比较,干细胞移植组、分化细胞移植组大鼠学习、记忆分数均显著提高(P < 0.01)。电镜观察模型组大鼠海马区神经细胞可见明显损伤,干细胞移植组损伤减轻,分化细胞移植组多数神经细胞结构正常。证实骨髓间充质干细胞移植可以提高老年性痴呆大鼠的认知能力,且定向神经诱导分化的骨髓间充质干细胞移植治疗效果优于未分化的骨髓间充质干细胞,提示骨髓间充质干细胞减少海马组织神经细胞变性坏死可能是其改善老年性痴呆大鼠认知功能障碍的作用机制之一。     

Immunocytochemical localization of three vesicular glutamate transporters in the cat retina

Vesicular transporters play an essential role in the packaging of glutamate for synaptic release and so are of particular importance in the retina, where glutamate serves as the neurotransmitter for photoreceptors, bipolar cells, and ganglion cells. In the present study, we have examined the distribution of the three known isoforms of vesicular glutamate transporter (VGLUT) in the cat retina. VGLUT1 was localized to all photoreceptor and bipolar cells, whereas VGLUT2 was found in ganglion cells. This basic pattern of complementary distribution for the two transporters among known populations of glutamatergic cells is similar to previous findings in the brain and spinal cord. However, the axon terminals of S-cone photoreceptors were found to express both VGLUT1 and VGLUT2 and some ganglion cells labeled for both VGLUT2 and VGLUT3. Such colocalizations suggest the existence of dual modes of regulation of vesicular glutamate transport in these neurons. Staining for VGLUT2 was also present in a small number of varicose processes, which were seen to ramify throughout the inner plexiform layer. These fibers may represent axon collaterals of ganglion cells. The most prominent site of VGLUT3 immunoreactivity was in a population of amacrine cells; the axon terminals of B-type horizontal cells were also labeled at their contacts with rod spherules. The presence of the VGLUT3 transporter at sites not otherwise implicated in glutamate release may indicate novel modes of glutamate signaling or additional roles for the transporter molecule.     

Distribution of monoamine-synthesizing neurons in the human medulla oblongata

We have employed immunohistochemical and morphometric procedures to study the distribution of monoamine-synthesizing neurons in the medulla oblongata of the adult human, utilizing antibodies to tyrosine hydroxylase (TH), phenylethanolamine N-methyltransferase (PNMT), and phenylalanine hydroxylase (PH8). In the human brain, the antigen with which PH8 reacts occurs within neurons that presumably synthesize serotonin (Haan et al., '87). Neurons containing these antigens were mapped and counted in successive coronal sections with the aid of a computer-assisted procedure. The results indicate that monoamine-synthesizing neurons are distributed in the human brain in patterns broadly similar to those described for other species. TH-immunoreactive cells extended caudorostrally for approximately 32 mm commencing at the spinomedullary junction and ending 8 mm caudal to the pontomedullary junction. In coronal sections these TH-immunoreactive neurons were seen in the lateral medulla dorsal to the inferior olive extending in a continuous band to the dorsomedial medulla. Above the obex the majority of these cells apparently synthesize adrenaline since many PNMT-immunoreactive cells were also found in this region. There were few or no PNMT-immunoreactive cells caudal to the obex, indicating that the TH-immunoreactive cells in this region synthesize either noradrenaline or dopamine. Approximately 65% of these TH-immunoreactive neurons contained melanin pigment, whereas few or no PNMT-immunoreactive cells contained melanin pigment. PH8-immunoreactive cells extended throughout the rostrocaudal extent of the medulla oblongata (approximately 40 mm). In coronal sections the majority were found in the medullary raphe nuclei. However, many cells throughout the rostrocaudal extent of the medulla were found laterally intermingled with catecholamine-synthesizing neurons. Occasional neurons in the lateral medulla appeared to contain both PH8- and TH-immunoreactivity.     

血管组织工程种子细胞在再生医学中的应用*☆◇

背景：小口径人工血管替代人体小动脉和静脉一直未获得满意的效果，因此研制出一种拥有较高远期通畅率的小口径人工血管成为了一个重要的研究课题。 目的：综述种子细胞在血管组织工程的研究进展。 方法：以 “Vascular tissue engineering, Seeding cells”为检索词，应用计算机检索Pubmed 数据库1960/2009有关文章。纳入有关血管组织工程种子细胞的文献。排除原始文献设计方法简单、结果可靠性差、非英文文献及结果重复的文献，保留35篇文献做进一步分析。 结果与结论：内皮细胞和平滑肌细胞是目前常用的种子细胞。内皮细胞和平滑肌细胞共同培养的体系，模拟体内环境，保持内皮细胞和平滑肌细胞具有正常的分泌功能和表型。骨髓间充质细胞可被有效的分离和扩增，在特定培养条件下可以诱导分化为多种血管细胞。在再生医学和生物组织工程方面有强大的潜力。     

Cellular and subcellular distribution of NMDA receptor subunit NR2B in the retina

Immunocytochemical studies showed the presence of staining for the N-methyl-D-aspartate (NMDA)-R2B glutamate receptor subunit at multiple sites in the cat retina. Reaction product in photoreceptor cells was localized at the inner/outer segment junction and in the axon terminals. Staining within the inner retina was limited to ganglion cells and their dendrites ramifying throughout the inner plexiform layer. These cells were seen to receive synaptic input from cone bipolar cells in both sublaminae. As with other glutamate receptor subunits, this immunoreactivity was typically confined to a single postsynaptic element at a cone bipolar dyad complex. Immunocytochemical localization of the NMDA-R1 subunit, considered to be an essential component of functional receptors, showed a widespread distribution across the retina including all the sites where NMDA-R2B staining was seen. Immunoprecipitation and Western blot analysis were used to confirm the presence of the NR2B receptor protein and its association with the NR1 subunit in both proximal and distal retinal layers. The findings suggest that NMDA-R2B subunits are positioned for multiple functions within the retina.     

周围神经组织工程中种子细胞的最新研究进展

典型的组织工程化人工神经主要包括种子细胞、支架材料以及有助于细胞生长、分化的细胞外基质，其中数量足够、不引起免疫排斥且有再生活力的种子细胞是其前提和基础。目前常用的种子细胞有雪旺氏细胞（SCs）、嗅球成鞘细胞（OECs）、骨髓基质细胞（BMSCs）和神经干细胞（NSCs）等。SCs一直是周围神经损伤修复研究领域的热点，OECs、BMSCs和NSCs修复周同神经损伤也在起步中。本从组织工程方面就上述四种细胞的最新研究进展进行综述，同时就存在的问题进行讨论。[第一段]     

Differential regulation of ciliary neurotrophic factor receptor-α expression in all major neuronal cell classes during development of the chick retina

Ciliary neurotrophic factor (CNTF) exerts a multiplicity of effects on a broad spectrum of target cells, including retinal neurons. To investigate how this functional complexity relates to the regulation of CNTF receptor α (CNTFRα) expression, we have studied the developmental expression of the receptor protein in chick retina by using immunocytochemistry. During the course of development, the receptor is expressed in all retinal layers, but three levels of specificity can be observed. First, the expression is regulated temporally with immunoreactivity observed in ganglion cells (embryonic day 8 [E8] to adult), photoreceptor precursors (E8–E12), amacrine cells (E10 to adult), bipolar cells (E12–E18), differentiated rods (E18 to adult), and horizontal cells (adult). Second, expression is restricted to distinct subpopulations of principal retinal neurons: preferentially, large ganglion cells; subpopulations of amacrine cells, including a particular type of cholinergic neuron; a distinctly located type of bipolar cell; and rod photoreceptors. Third, expression exhibits subcellular restriction: it is confined largely to dendrites in mature amacrine cells and is restricted entirely to outer segments in mature rods. These data correlate with CNTF effects on the survival of ganglion cells and mature photoreceptors, the in vitro differentiation of photoreceptor precursors and cholinergic amacrine cells, and the number of bipolar cells in culture described here or in previous studies. Thus, our results demonstrate an exceptional degree of complexity with respect to the regulation of neuronal CNTFRα expression in a defined model system. This suggests that the same signaling pathway is used to mediate a variety of regulatory influences, depending on the developmental stage and cell type. J. Comp. Neurol. 400:244–254, 1998. © 1998 Wiley-Liss, Inc.     

Distribution of neuropeptidelike immunoreactivities in the guinea pig olfactory bulb

The distribution of neuropeptidelike immunoreactivities in the adult guinea pig olfactory bulb was studied immunohistochemically with antisera raised against neurotensin (NT), substance P (SP), methionine-enkephalin-Arg6-Gly7-Leu8 (ENK), somatostatin (SOM), neuropeptide Y (NPY), and cholecystokinin-8 (CCK). In the main olfactory bulb, NT-like immunoreactive (NT-IR) neurons were found among periglomerular cells. In addition, a few periglomerular cells showed ENK-like immunoreactivity. Granule cells displaying SP- or ENK-like immunoreactivities and short axon cells with SOM- or NPY-like immunoreactivities were observed in the deeper half of the granule cell layer. SOM-IR short axon cells were also seen in the external plexiform layer. Dense NT- or NPY-IR fibers were distributed in superficial lamina of the granule cell layer, and sparse SP- or CCK-IR fibers were found in the glomerular layer. In the accessory olfactory bulb, some mitral, periglomerular, and granule cells showed NT-like immunoreactivity. SP- or ENK-IR granule cells were also observed. These results are discussed in relation to laminar organization of the olfactory bulb. The most characteristic features of peptide distribution in guinea pigs, as compared with that of rats in previous studies, were the relative abundance of NT-IR structures and the lack of SP- and CCK-IR juxtaglomerular and tufted cells.     

诱导性多潜能干细胞的应用前景

背景：通过基因转染的方式将已分化的体细胞重编程为诱导性多潜能干细胞,是近年来干细胞领域一项令人瞩目的新技术。由于诱导性多潜能干细胞摆脱了材料来源和伦理学的限制,因此其出现为特异的细胞治疗,特别是再生医学带来新的曙光。 目的：从诱导性多潜能干细胞的制备流程、产生的限制条件与机制、患者诱导性多潜能干细胞的获得及应用前景等方面做一评述。 方法：由第一作者检索PubMed数据库(www.ncbi.nlm.nih.gov/PubMed)2006-01/2010-03有关诱导性多潜能干细胞制备、产生机制的文章,检索词“induced pluripotent stem cells”,限定语言种类为English;同时手工检索部分文章。排除重复性研究,最终纳入34篇符合标准的文献。 结果与结论：诱导性多潜能干细胞系的建立主要包括以下几个步骤：①重组因子的选择。②目的细胞的选择。③重组因子的导入。④重组因子在目的细胞内的表达。⑤诱导性多潜能干细胞的产生。⑥重组细胞的鉴定。DNA甲基化、组蛋白的修饰作用和甲基化以及p53基因的表达在体细胞重编程为多潜能干细胞的过程中具有重要作用。虽然诱导性多潜能干细胞技术的研究仍然处于初级阶段,但是毫无疑问其具有广阔的应用前景。特别是患者特异性和疾病特异性诱导性多潜能干细胞的获得对于更好地理解疾病的发病机制及药物安全性评价提供了巨大的细胞种子资源。