乌司他丁对小鼠脑缺血-再灌注损伤的保护作用及对Nrf2/HO-1通路影响的研究

目的观察乌司他丁对小鼠脑缺血-再灌注后脑损伤的保护作用及对Nrf2/HO-1通路的影响。方法健康成年雄性CD1小鼠120只,随机分成4组(n=30):假手术组、脑缺血-再灌注组、乌司他丁小剂量组和乌司他丁大剂量组,采用改良线栓法制备大脑中动脉缺血-再灌注模型。缺血60min,再灌注24h后,采用Western blot和RT-q PCR来观察脑缺血后梗死侧皮质Nrf2和HO-1蛋白及基因表达变化,比较各组神经功能,脑梗死体积,脑组织含水量,梗死侧皮质丙二醛(MDA)和超氧化物歧化酶(SOD)含量。结果乌司他丁能够明显上调缺血脑皮质组织Nrf2、HO-1的表达,增加SOD活性,减少MDA的含量,改善神经功能缺失,减轻脑水肿,减小梗死体积。结论 Nrf2/HO-1通路参与了脑梗死后乌司他丁对缺血脑组织的保护作用。     

二烯丙基硫醚对大鼠脑缺血再灌注损伤后Nrf2、NQ01表达的影响

目的 探讨二烯丙基硫醚对大鼠局灶性脑缺血再灌注损伤后Nrf2、NQ01表达的影响.方法 实验动物随机分为假手术组、缺血再灌注组、200mg/kg二烯丙基硫醚预处理组.采用线栓法制备大鼠大脑中动脉缺血再灌注模型,缺血2h再灌注24h后进行神经行为学评分,测定脑梗死体积及脑组织中SOD、MDA活性,采用免疫荧光和Western Blot测定Nrf2、NQ01蛋白分子的表达.结果 与缺血再灌注组相比,大鼠经二烯丙基硫醚预处理后神经损害症状减轻,脑梗死体积缩小,SOD活性增强,同时MDA活性受到抑制,Nrf2、NQ01I蛋白分子表达上调.结论 二烯丙基硫醚对大鼠脑缺血再灌注损伤具有一定的神经保护作用,可能与其增强大鼠脑组织抗氧化酶活性和激活Nrf2/NQ01通路有关.     

TLR4对大鼠急性脑梗死体积与Nrf2、HO-1表达水平的影响

目的探讨Toll样受体4(TLR4)对大鼠急性脑梗死体积与核因子E2相关性因子2(Nrf2)、血红素加氧酶-1(HO-1)表达水平的影响。方法制备大鼠急性脑缺血模型后,比较模型组与TLR4特异性抑制剂-TAK-242组行为学及脑梗死体积、Nrf2、HO-1表达水平改变;通过Morris水迷宫实验比较不同组小鼠脑梗死后学习功能的恢复;TTC染色比较不同组脑梗死体积变化;免疫组织化学染色及Western Blot比较各组Nrf2、HO-1表达水平变化。结果与假手术组比较,模型组与TAK-242组潜伏期延长,穿越平台次数减少,同时TAK-242组潜伏期明显短于模型组(P0.05);TAK-242组穿越平台的次数明显多于模型组(P0.05)。TAK-242组脑梗死体积明显小于模型组(P0.05)。Nrf2、HO-1主要表达在神经元与星形胶质细胞中。另外,假手术组Nrf2、HO-1的表达水平明显低于模型组与TAK-242组,同时TAK-242组Nrf2、HO-1的表达水平明显高于模型组。3组大鼠Nrf2、HO-1表达水平有明显差异(P0.05),且TAK-242组Nrf2、HO-1的表达水平显著高于模型组(P0.05)。结论通过TLR4特异性抑制剂-TAK-242干预可以显著改善大鼠急性脑缺血的神经功能,减小脑梗死体积,促进神经元与星形胶质细胞Nrf2、HO-1的表达。     

实验性脑缺血损伤大鼠Nrf2/ARE信号通路相关基因NQO1、GCLC和GCLM表达的变化

目的从抗氧化应激角度观察大鼠脑缺血损伤后Nrf2/ARE信号通路相关基因NQO1、GCLC和GCLM mRNA及其蛋白表达的影响。方法将80只SD大鼠随机分为两组:假手术组(SO)和模型组(MCAO),采用线栓法制备局灶性脑缺血大鼠(MCAO)模型。每组大鼠40只,每组根据取材时间点12 h、1 d、2 d、3 d可以分为每组4个亚组,每个亚组10只大鼠。采用化学荧光法测定脑组织ROS水平,ELISA法检测GSH活性;分别采用qRT-PCR和Western blot法观察NQO1、GCLC和GCLM mRNA及其蛋白在缺血半暗带表达变化。结果 (1)与SO组比较,MCAO组脑组织中GSH活力显著降低,ROS活性显著升高(P 0. 05或P 0. 01);(2)与SO组比较,MCAO组各时间点NQO1、GCLC和GCLM mRNA及其蛋白表达均于缺血再灌注后12 h开始明显上升,24 h达高峰,随再灌注时间延长其表达逐渐下降,但仍保持较高表达水平(P 0. 05或P 0. 01)。结论大鼠脑缺血再灌注损伤后激活了Nrf2信号通路下游因子NQO1、GCLC和GCLM,从而发挥抗氧化应激作用。     

Nrf2-ARE信号通路对脑出血灶周神经保护作用的机制研究

目的研究大鼠脑出血后Nrf2-ARE通路HO-1对出血灶周神经保护作用及其相关机制探讨。方法采用SD大鼠基底节自体股动脉血注射法建立脑出血模型,分4组:单纯脑出血(ICH)组、莱菔硫烷(SFN)组、维甲酸(RA)组、对照组,观察不同时间点大鼠神经功能评分,取脑组织行免疫荧光检查、Western blot、RT-PCR检测Nrf2、HO-1、NF-κB、TNF-α表达。对所得数据进行统计分析,观察这些指标的变化。结果 SFN组与ICH组比较,神经功能障碍明显减轻,出血灶周Nrf2因子、HO-1抗氧化蛋白表达均升高,于3 d达高峰值,持续表达至7 d;SFN组NF-κB、TNF-α表达下降;RA组大鼠死亡率最高,神经功能障碍较ICH组及SFN组均严重,Nrf2因子、HO-1抗氧化蛋白表达均较SFN组和ICH组低,持续性抑制作用可能持续7 d左右,RA处理组NF-κB、TNF-α表达升高,炎性反应持续时间可能超过7 d。结论 RA抑制Nrf2解离及转入核,抑制Nrf2-ARE信号通路的抗炎性作用,SFN激活Nrf2-ARE信号通路可提高HO-1抗氧化酶表达,减轻脑出血后灶周炎性反应,具有神经保护作用,提示Nrf2-ARE信号通路将是治疗脑出血灶周炎性损伤的新方向。     

血红素加氧酶-1 在肢体缺血后处理对脑缺血再灌注损伤的保护作用

目的探讨血红素加氧酶-1(HO-1)在肢体缺血后处理(LPostC)对脑缺血再灌注损伤的保护作用及机制。方法 80只雄性SD大鼠随机分为假手术组(sham组)、缺血再灌注组(I/R组)、肢体缺血后处理组(LPostC组)和血红素加氧酶抑制剂锌原卟啉组(ZnPP组),每组20只。采用石蜡线栓法建立大脑中动脉缺血再灌注模型。夹闭双侧股动脉5 min,松开5 min,反复循环3次,制备LPostC模型。再灌注24 h后,采用2,3,5-氯化三苯基四氮唑(TTC)法测脑梗死体积;末端脱氧核苷酸转移酶介导的dUTP缺口末端标记测定(TUNEL)法检测神经细胞凋亡;用免疫组化和Western blotting方法测定HO-1的表达;分光光度计法测脑组织中丙二醛(MDA)和超氧化物歧化酶(SOD)的水平。结果与sham组相比,I/R组HO-1表达减少,SOD活性降低,MDA含量增加(均P0.05)。与I/R组相比,LpostC组脑梗死体积缩小,神经细胞凋亡数量显著减少,HO-1表达明显增加,SOD活性升高且MDA含量降低(均P0.05)。与LPostC组相比,ZnPP组脑梗死体积扩大,神经细胞凋亡数量增多,HO-1表达明显减少,SOD活性降低,MDA含量升高(均P0.05)。结论 LPostC对脑缺血再灌注损伤具有保护作用,其作用机制可能与HO-1的表达增加有关。     

糖尿病小鼠加重脑缺血后认知障碍的相关机制研究

目的探讨氧化应激损伤对糖尿病小鼠局灶性脑缺血后认知功能的影响。方法制备糖尿病模型,参照Longa等方法制成大鼠局灶性大脑中动脉阻断(MCAO)模型,采用Longa法进行神经功能缺失评分,苏木精-伊红染色测定梗死体积,Western blotting法检测Nrf2/HO-1及认知相关性蛋白p-Ca MKII/Ca MKII、p-Synapain/Synapain、p-Glu R1/Glu R1的蛋白表达。结果糖尿病小鼠局灶性脑缺血-再灌注后神经功能缺失评分、梗死体积较非糖尿病组明显严重(P0.05),同时伴有脑组织Nrf2/HO-1、p-Ca MKII/Ca MKII、p-Synapain/Synapain、p-Glu R1/Glu R1蛋白表达下调(P0.05)。结论糖尿病小鼠局灶性脑缺血—再灌注后Nrf2/HO-1表达降低,且与神经功能缺失及p-Ca MKII/Ca MKII、p-Synapain/Synapain、p-Glu R1/Glu R1表达下调一致,提示Nrf2/HO-1是糖尿病脑梗死后导致认知障碍的关键环节。     

大鼠短暂前脑缺血诱导IL-1β蛋白表达的时间规律

目的　探讨大鼠脑缺血模型脑内 IL-1 β蛋白表达情况。方法　采用左侧大脑中动脉插入丝线结扎(LMCAO)方法制造大鼠脑缺血模型。分别按照 1、2、4d不同缺血时间组和缺血再灌后 3 0 min～ 7d的不同再灌时间点取材 ,假手术大鼠作为对照组。应用免疫组化方法标记实验各组大鼠脑组织中 IL-1 β阳性神经元的数量。结果　在不同缺血时间组中 ,假手术组少见 IL-1β蛋白表达 ,模型组大鼠随着缺血时间的延长 ,IL-1β蛋白表达数量增多。在不同再灌时间组中 ,假手术大鼠脑内两侧半球少见散在的 IL-1 β免疫反应细胞 ,模型组 IL-1 β免疫活性细胞在线栓栓塞 (MCAO)缺血再灌后缺血半球从 1 h后开始表达 ,2 h后免疫反应继续增加并向未缺血半球侧表达 ,此时表达达到高峰 ,4h后表达开始减弱 ,至第 7天 IL-1 β免疫活性细胞在所检测脑区为最低水平表达。结论　本研究证明了大鼠大脑中动脉栓塞再灌后可诱发 IL-1 β表达增加 ,且 IL-1 β的表达具有明显的时间规律。     

脑缺血恢复期骨髓间充质干细胞移植对神经功能和促血管生成素-1、2及其受体表达的影响

目的 探讨腩缺血恢复期骨髓间充质干细胞(BMSCs)移植对神经功能和促血管生成素(Ang)-1、Ang-2及酪氨酸激酶受体-2(Tie-2)表达的影响.方法 42只SD大鼠随机分为脑缺血对照组(对照组,12只)、BMSC移植组(15只)及假手术组(15只),各组又分为缺血后28 d、35 d、42 d 3个亚组.用线栓法制作脑缺血大鼠模型,用改良黏附物移除试验(MST)评估大鼠神经功能.在脑缺血后21 d,给BMSCs移植组大鼠尾静脉注射BMSCs,对照组大鼠注射等体积PBS.在脑缺血后28 d、35 d、42 d(移植后7 d、14 d、21 d),用逆转录-聚合酶链反应(RT-PCR)及Western Blotting法检测大鼠缺血周围脑组织Ang-1、Ang-2及Tie-2 mRNA和蛋白的水平.结果 BMSCs移植组大鼠各时间点亚组的MST评分均显著高于对照组(均P<0.05);BMSCs移植组及对照组各时间点亚组脑组织的Ang-1、Tie-2 mRNA和蛋白水平明显高于假手术组(P<0.05～0.01),脑缺血后28 d、35 d,BMSCs移植组脑组织Ang-1、Tie-2 mRNA及蛋白水平均明显高于对照组(均P<0.01),而脑缺血后42 d两组之间的差异无统计学意义;3组各时间点亚组脑组织Ang-2 mRNA及蛋白水平的差异均无统计学意义.结论 脑缺血恢复期BMSCs移植能改善神经功能,并使缺血周围脑组织Ang-1、Tie-2的表达水平明显增高.而对Ang-2表达无明显影响.     

Nrf2-ARE在大鼠创伤性脑损伤模型中的表达及意义

目的 研究Nrf2-ARE在创伤性脑损伤后动态表达和分布情况,探讨其意义.方法 制作大鼠脑损伤模型,应用RT-PCR和Western blot方法检测大鼠脑损伤后1、6、12、24、48和72 h损伤侧脑皮层Nrf2-mRNA及蛋白的变化,应用免疫荧光观察Nrf2在损伤侧皮层中表达和分布情况.结果 TBI组术后各时间点mRNA水平无明显变化(P＞0.05);但其Nrf2的蛋白水平均高于假手术组(P＜0.01).免疫荧光显示:假手术组中,Nrf2在正常脑组织中神经元和胶质细胞的胞质中有少量表达;损伤后,Nrf2在损伤侧皮质中神经元和胶质细胞的胞核和胞质中表达明显升高.结论 Nrf2在TBI早期即可被激活,提示Nrf2-ARE通路可能参与了TBI后内源性应激防御机制.     

金属蛋白酶2、血管内皮生长因子和肿瘤抑制因子在人脑胶质瘤中的表达和临床意义

目的:探讨人脑胶质瘤中的金属蛋白酶2(MMP-2)、血管内皮生长因子(VEGF)和肿瘤抑制因子(P16)的表达。方法:应用免疫组化法检测55例胶质瘤组织中的MMP-2、VEGF和P16蛋白的表达,通过原位杂交检测MMP-2 mRNA的表达。结果:胶质瘤的恶性程度与MMP-2、VEGF表达和P16的缺失表达呈正相关,随着胶质瘤的恶性程度的增高而增加。结论:胶质瘤的恶性程度由多种因素决定。胶质瘤中MMP-2含量越高,肿瘤细胞在浸润的过程中突破血脑屏障的能力越强;VEGF的表达增加,肿瘤的血液供应越丰富,恶性程度越高。P16蛋白缺失率高,组织学分化程度低,在一定程度上反映了胶质瘤细胞的恶性生物学行为。     

慢性脑低灌注对大鼠皮层核因子E2相关因子2表达的影响

目的 研究慢性脑低灌注大鼠皮层核因子E2相关因子2(Nrf2)的表达.方法 用随机数字表法将大鼠分为双血管结扎术(2VO)-3周组、2VO-8周组和假手术组,2VO术式制备慢性脑低灌注大鼠模型并在相应时间点取材,采用免疫组化染色、实时定量PCR方法检测大鼠皮层Nrf2的表达,用硫代巴比妥酸法测定丙二醛(MDA)含量.结果 免疫组化染色结果显示,与假手术组(38.01%±4.51%)相比,2VO-3周组(50.18%±14.22%)、2VO-8周组(23.15%±7.42%)大鼠皮层Nrf2阳性细胞比例差异均无统计学意义(P＞0.05);与2VO-3周组相比,2VO-8周组大鼠皮层Nrf2阳性细胞比例明显降低,比较差异有统计学意义(P＜0.05).实时定量PCR结果提示,2VO-8周组大鼠皮层Nrf2 mRNA的表达(相对扩增倍数)较2VO-3周组降低,但差异无统计学意义(P＞0.05).生化检测发现,与假手术组[(3.894±0.512)nmol/mg]相比,2VO-8周组大鼠皮层MDA含量[(6.855±1.351)nmol/mg]明显升高,比较差异有统计学意义(P＜0.05).结论 慢性脑低灌注大鼠皮层MDA含量随时间延长而不断增加,除3周时蛋白表达上调外,Nrf2蛋白与mRNA水平均有不同程度减低,提示慢性脑低灌注状态时氧化性损伤持续加重,这可能与内源性抗氧化系统受到抑制有关.

Abstract：

Objective To examine the effect of chronic cerebral hypoperfusion (CCH) on the expression of nuclear factor E2-related factor 2 (Nrf2) in rat cortex. Methods Rats were randomly divided into 2 operated groups and a sham-operated group; rat models of chronic cerebral hypoperfusion in the 2 operated groups were established by occlusion of bilateral common carotid arteries (2VO) for 3 and 8 weeks, respectively. The RNA and protein contents of Nrf2 in the cortex were detected by immunohistochemistry and real-time quantitative PCR, respectively, and the content of malonaldehyde (MDA) was measured by thiobarbituric acid-reactive substance assay. Results A significantly lower percentage of Nrf2-positive cells in the cortex of 2VO-8w group (23.15%±7.42%) was noted as compared with that in the 2VO-3w group (50.18%±14.22%) (P＜0.05); no significant differences on the percentage of Nrf2-positive cells were noted between the sham-operated group (38.01%±4.51%) and the 2 operated groups (P＞0.05). Though the RNA content of Nrf2 in the cortex of 2VO-8w group (0.993 ±0.492)decreased as compared with that in the 2VO-3w group (1.536±0.493)(P＞0.05), no statistical difference was noted between the sham-operated group (1.690± 1.195) and both the 2VO-3w group and the 2VO-8w group (P＞0.05). And the content of MDA in the 2VO-8w group ([6.855±1.351] nmol/mg) was significantly increased as compared with that in the sham-operated group ([3.894±0.512] nmol/mg) (P＜0.05). Conclusion The content of MDA keeps increasing. Additionally, except the protein expression up-regulates 3 weeks after occlusion, the RNA and protein expressions of Nrf2 in rat cortex are down-regulated with the process of CCH, suggesting that oxidative damage become much severe with theprocess of CCH, which may be partly attributed to the dysfunction of endogenous antioxidative mechanisms.     

Effect of transforming growth factor-β1 and -β2 on Schwann cell proliferation on neurites

Mechanisms regulating Schwann cell proliferation during development are unclear. Schwann cell division is known to be driven by an unidentified mitogen present on the surface of axons, but it is not known whether other molecules play a role in regulating this proliferation. Transforming growth factor-beta (TGF-β) which is found in the developing peripheral nervous system (PNS) and is mitogenic for neuron-free Schwann cells in vitro could be involved. We have investigated the effects of TGF-β 1, TGF-β 2 and antibodies to TGF-β and TGF-β 2 on axon driven Schwann cell proliferation. Rat embryonic dorsal root ganglion neurons (DRG) neurons and Schwann cells from the sciatic nerve were isolated, purified and recombined in vitro. Confirming earlier reports by others, we observed that TGF-β 1 and TGF-β 2 added to the culture medium stimulated the proliferation of Schwann cells in the absence of neurons. However, when added to neuron-Schwann cell co-cultures, TGFβ caused a variable response ranging from no effect to moderate inhibition of Schwann cell proliferation in different experiments. A stimulation of Schwann cell proliferation by TGFβ was never observed in neuron-Schwann cell co-cultures. Antibodies to TGF-β and TGF-β 2 did not influence axon driven Schwann cell proliferation. To further determine the role of TGF-β in Schwann cell proliferation and myelination, we studied Schwann cell proliferation in cultures from mice in which the TGF-β 1 gene was delected by homologous recombination. Neuron-Schwann cell cultures from wild-type, heterozygous and homozygous mice were used. No differences were observed in either Schwann cell proliferation or myelination between cultures obtained from homozygous mutants and their heterozygous and wild-type controls. These findings suggest that TGF-β does not function as a part of the mitogenic mechanism presented by neurons to Schwann cells, but that the presence of active TGFβ in the cellular environment might regulate the degree of proliferation induced by neuronal contact. Copy 1995 Wiley-Liss, Inc.     

Activation of the Nrf2-ARE signal pathway after blast induced traumatic brain injury in mice

Background: Treatment of blast-induced traumatic brain injury (bTBI) has been hindered. Previous studies have demonstrated that oxidative stress may contribute to the pathophysiological process. The nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response element (ARE) signaling pathway exhibits a protective effect after traumatic brain injury (TBI). This study explored whether the Nrf2-ARE pathway was activated in a modified bTBI mouse model.

Method: Mice were randomly divided into six groups: the 6?h, 1 d, 3 d, 7 d and 14 d after bTBI groups and a sham group. The protein levels of nuclear Nrf2, heme oxygenase-1 (HO-1) and NAD(P)H: quinone oxidoreductase-1 (NQO1) were detected using western blot, and HO-1 and NQO1 mRNA levels were determined by real-time quantitative polymerase chain reaction. Moreover, HO-1 and Nrf2 were localized using histological staining.

Results: The protein level of the Nrf2-ARE pathway in the frontal lobe increased significantly in the 3 d after bTBI. The HO-1 and NQO1 mRNA levels also reached a peak in the frontal lobe 3 d after bTBI. The histological staining demonstrated higher expression of HO-1 in the frontal lobe and hippocampus 3 d after bTBI, when nuclear import of Nrf2 reached a peak in the frontal lobe.

Conclusions: bTBI activated the Nrf2-ARE signaling pathway in the brain. The peak activation time in the frontal lobe may be 3 d after injury, and activating the Nrf2 pathway could be a new direction for treatment.     

Regulation of astrocyte GFAP expression by TGF-β1 and FGF-2

Astrocytes play a critical role in the development of the CNS and its response to injury and disease. A key indicator of astrocyte activation is the increased accumulation of intermediate filaments composed of glial fibrillary acidic protein (GFAP). Treatment of astrocytes in vitro with transforming growth factor-β1 (TGF-β1) produced little morphological change, but resulted in a significant increase in GFAP mRNA and protein. Treatment with basic fibroblast growth factor (FGF-2) produced a dramatic change from a polygonal to a stellate morphology, and resulted in a significant decrease in GFAP mRNA and protein. FGF-2 also inhibited the TGF-β1-mediated increase in GFAP mRNA and protein. Cycloheximide did not block the effects of TGF-β1 or FGF-2 on GFAP mRNA levels, but blocked the inhibitory effects of FGF-2 on the TGF-β1-mediated increase in GFAP expression. All effects of FGF-2 were blocked by co-incubation with 5′-methylthioadenosine, a specific inhibitor of FGF-2-induced tyrosine kinase activity and FGF receptor (FGFR) autophosphorylation. We also examined astrocyte expression of FGFR, and demonstrate the presence of FGFR 1 and 2, and lower levels of FGFR 3. Our results demonstrate that TGF-β1 and FGF-2 cause differential effects on the astrocyte cytoskeleton and morphology, suggesting an uncoupling of process outgrowth from GFAP synthesis. GLIA 22:202–210, 1998. © 1998 Wiley-Liss, Inc.     

Microglial major histocompatibility complex glycoprotein-1 in the axotomized facial motor nucleus: regulation and role of tumor necrosis factor receptors 1 and 2

Presentation of antigen is key to the development of the immune response, mediated by association of antigen with major histocompatibility complex glycoproteins abbreviated as MHC1 and MHC2. In the current study, we examined the regulation of MHC1 in the brain after facial axotomy. The normal facial motor nucleus showed no immunoreactivity for MHC1 (MHC1-IR). Transection of the facial nerve led to a strong and selective up-regulation of MHC1-IR on the microglia in the affected nucleus, beginning at day 2 and reaching a maximum 14 days after axotomy, coinciding with a peak influx of the T lymphocytes that express CD8, the lymphocyte coreceptor for MHC1. Specificity of the MHC1 staining was confirmed in beta2-microglobulin-deficient mice, which lack normal cell surface MHC1-IR. MHC1-IR was particularly strong on phagocytic microglia, induced by delayed neuronal cell death, and correlated with the induction of mRNA for tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and interferon-gamma and the influx of T lymphocytes. Mice with severe combined immunodeficiency (scid), lacking T and B cells, showed an increase in the number of MHC1-positive nodules but no significant effect on overall MHC1-IR. Transgenic deletion of the IL1 receptor type I, or the interferon-gamma receptor type 1 subunit, did not affect the microglial MHC1-IR. However, a combined deletion of TNF receptors 1 and 2 (TNFR1&2-KO) led to a decrease in microglial MHC1-IR and to a striking absence of the phagocytic microglial nodules. Deletion of TNFR2 (p75) did not have an effect; deletion of TNFR1 (p55) reduced the diffuse microglial staining for MHC1-IR but did not abolish the MHC1(+) microglial nodules. In summary, neural injury leads to the induction of MHC1-IR on the activated, phagocytic microglia. This induction of MHC1 precedes the interaction with the immune system, at least in the facial motor nucleus model. Finally, the impaired induction of these molecules, up to now, only in the TNFR-deficient mice underscores the central role of TNF in the immune activation of the injured nervous system.     

神经妥乐平通过Nrf2/HO-1/NQO1通路发挥对帕金森病大鼠的神经保护作用

目的 探讨神经妥乐平对帕金森病(PD)大鼠的神经保护作用及其相关机制.方法 SD大鼠分为对照组、PD组(PD造模)、神经妥乐平低剂量组(PD造模+腹腔注射0.6 Nu·kg-1神经妥乐平溶液)、神经妥乐平高剂量组(PD造模+腹腔注射1.2 Nu·kg-1 神经妥乐平溶液)和通路抑制组(PD造模+腹腔注射1.2 Nu·k...     

The FGF-2/FGFRs neurotrophic system promotes neurogenesis in the adult brain

Neurogenesis occurs in two regions of the adult brain, namely, the subventricular zone (SVZ) throughout the wall of the lateral ventricle and the subgranular zone (SGZ) of the dentate gyrus (DG) in hippocampal formation. Adult neurogenesis requires several neurotrophic factors to sustain and regulate the proliferation and differentiation of the adult stem cell population. In the present review, we examine the cellular and functional aspects of a trophic system mediated by fibroblast growth factor-2 (FGF-2) and its receptors (FGFRs) related to neurogenesis in the SVZ and SGZ of the adult rat brain. In the SVZ, FGF-2 is expressed in GFAP-positive cells of SVZ but is not present in proliferating precursor cells, which instead express FGFR-1 and FGFR-2, but not FGFR-3 mRNA, although expressed in the SVZ, and FGFR-4. Therefore, it seems that in the SVZ FGF-2 may be released by GFAP-positive cells, different from the precursor cell lineage, and via volume transmission it reaches the proliferating precursor cells. FGFR-1 mRNA is also expressed in the SGZ and is localized in BrdU-labeled precursor cells, whereas FGFR-2 and FGFR-3 mRNA, although expressed in the SGZ, are not located within proliferating precursor cells. An aged-related decline of proliferating precursor cells in the SVZ and DG of old rats has been well documented, and there is the suggestion that in part it could be the consequence of alterations in growth factor expression levels. Thus, the old precursors may respond to growth factors, suggesting that during aging the basic components for neuronal precursor cell proliferation are retained and the capacity to increase neurogenesis after appropriate stimulation is still preserved. In conclusion, the trophic system mediated by FGF-2 and its receptors contributes to create an important micro-environmental niche that promotes neurogenesis in the adult and aged brain. This article is dedicated to the special issue Brain Plasticity: Aging and Neuropychiatric Disorders.     

选择性自噬接头蛋白p62与Keap1-Nrf2信号通路在神经退行性疾病中的研究进展

在自噬小体形成的过程中,选择性自噬接头蛋白p62作为连接自噬相关蛋白、LC3、聚泛素化蛋白之间的桥梁,通过泛素信号途径将受损的蛋白质、线粒体及入侵的细菌转运到自噬小体中并降解。p62作为一种自噬衔接蛋白将自噬和Keap1-Nrf2 通路相关联。p62可竞争性结合Keap1,通过自噬途径将其清除,促使Nrf2解离入核,Nrf2结合到下游抗氧化元件p62启动子区又可促进p62的生成,形成正性反馈环路。神经退行性疾病病因复杂、发病机制尚不清楚,自噬失调以p62调控的非经典途径激活Keap1-Nrf2信号通路成为该领域研究热点。