加兰他敏对APP/PS1转基因小鼠海马区星形胶质细活化及C/EBPβ表达的影响

目的研究加兰他敏对APP/PS1转基因小鼠海马区星形胶质细胞活化、C/EBPβ表达及行为学的影响。方法选取10月龄雄性APP/PS1转基因小鼠20只,随机分为模型对照组(10只)和治疗组(10只),同月龄、同背景的C57BL/6野生型雄性小鼠10只作为正常对照组。治疗组皮下注射加兰他敏溶液5mg/kg,2次/d,连续治疗8周,正常对照组和模型对照组给予皮下注射等量生理盐水。应用Morris水迷宫实验于干预治疗8周后开始测定各组小鼠空间学习记忆能力,连续7d,采用免疫组织化学、免疫荧光及Western-blot方法观察各组小鼠海马区星形胶质细胞活化及C/EBPβ表达水平。结果与正常对照组相比,模型对照组和治疗组小鼠Morris检测第5、6天平均逃避潜伏期延长,穿越平台次数减少(P0.05,P0.05),而治疗组其逃避潜伏期较模型对照组缩短(P0.05),穿越平台次数增多(P0.05);同时治疗组小鼠星形胶质细胞活化被明显抑制,胶质纤维酸性蛋白(GFAP)的阳性表达面积〔(5.003±0.823)%〕及C/EBPβ的表达量(87.711±14.622)较模型对照组〔(7.116±1.040)%,119.920±16.901〕明显减少(P0.05,P0.05)。结论加兰他敏改善APP/PS1转基因AD小鼠的学习记忆能力可能与其抑制星形胶质细胞的活化及C/EBPβ的表达有关。     

Estradiol prevents Aβ25 35-inhibited long-term potentiation induction through enhancing survival of newborn neurons in the dentate gyrus

Aim and Methods: Estradiol (E2) is reported to attenuate β-amyloid (Aβ) accumulation and slow the progression of Alzheimer's disease (AD). This study explored the beneficial effect of E2 in AD using histological examination and electrophysiological recording technique in AD model mice created by intracerebroventricular injection of β-amyloid 25–35 (Aβ_25–35). Results: Infusion of Aβ_25–35 reduced the number of newborn neurons in the 2nd week after birth, a critical period for neurite growth, and impaired high-frequency stimulation-dependent long-term potentiation (LTP) induction in perforant path-granular synapses of hippocampal dentate gyrus (DG). Administration of E2 from the 2nd to 4th week after cell birth in Aβ_25–35-mice ameliorated the impairment of newborn neurons and LTP induction in DG. Acute application of E2 failed to increase the newborn neurons and rescue LTP induction in the DG of Aβ_25–35-mice. Conclusions: The effect of E2 in Aβ_25–35-impaired LTP induction depends on its neuroprotection improvement.     

Nicotine contributes to the neural stem cells fate against toxicity of microglial-derived factors induced by Aβ via the Wnt/β-catenin pathway

Recent studies have demonstrated that the molecules secreted from microglias play important roles in the cell fate determination of neural stem cells (NSCs), and nicotinic acetylcholine receptor agonist treatment could reduce neuroinflammation in some neurodegenerative disease models, such as Alzheimer's disease (AD). However, it is not clear how nicotine plays a neuroprotective role in inflammation-mediated central nervous diseases, and its possible mechanisms in the process remain largely elusive. The aim of this study is to improve the survival microenvironment of NSCs co-cultured with microglias in vitro by weakening inflammation that mediated by accumulation of β-amyloid peptide (Aβ). The viability, proliferation, differentiation, apoptosis of NSCs and underlying mechanisms associated with Wnt signaling pathway were investigated. The results showed that Aβ could directly damage NSCs. Furthermore, concomitant to elevated levels of TNF-α, IL-1β derived from microglias, the NSCs had been damaged more severely with the upregulation of Axin 2, p-β-catenin and the downregulation of β-catenin, p-GSK-3β, microtubule-associated protein-2, choline acetyltransferase. However, addition of 10 μmol/L nicotine before microglias treated with Aβ was beneficial to protect the NSCs against neurotoxicity of microglial-derived factors induced by Aβ, which partially rescued proliferation, differentiation and inhibited apoptosis of NSCs via activation of Wnt/β-catenin pathway. Taken together, these data imply that low concentration nicotine attenuates NSCs injury induced by microglial-derived factors via Wnt signaling pathway. Thus, treatment with nicotinic acetylcholine receptor agonist provides a promising research field for neural stem cell fate and therapeutic intervention in neuroinflammation diseases.     

Temporal control of glucocorticoid neurodynamics and its relevance for brain homeostasis,neuropathology and glucocorticoid-based therapeutics

Glucocorticoids mediate plethora of actions throughout the human body. Within the brain, they modulate aspects of immune system and neuroinflammatory processes, interfere with cellular metabolism and viability, interact with systems of neurotransmission and regulate neural rhythms. The influence of glucocorticoids on memory and emotional behaviour is well known and there is increasing evidence for their involvement in many neuropsychiatric pathologies. These effects, which at times can be in opposing directions, depend not only on the concentration of glucocorticoids but also the duration of their presence, the temporal relationship between their fluctuations, the co-influence of other stimuli, and the overall state of brain activity. Moreover, they are region- and cell type-specific. The molecular basis of such diversity of effects lies on the orchestration of the spatiotemporal interplay between glucocorticoid- and mineralocorticoid receptors, and is achieved through complex dynamics, mainly mediated via the circadian and ultradian pattern of glucocorticoid secretion. More sophisticated methodologies are therefore required to better approach the study of these hormones and improve the effectiveness of glucocorticoid-based therapeutics.     

Evaluation of periodontitis in hospital outpatients with major depressive disorder. A focus on gingival and circulating cytokines

An imbalance in stimulated cytokine production is associated with the etiopathogenesis of numerous diseases such as major depressive disorder (MDD) and periodontal disease. Increased cytokine levels have been reported in the gingival crevicular fluid (GCF) of patients with MDD. Thirty-six outpatients with MDD participated in this study. Each outpatient was age-matched (±3 years) with a healthy control (n = 36). The patients were controlled for race and smoking habits. Unstimulated and stimulated interleukin 6 (IL-6), interleukin 1β (IL-1β), and interferon-γ (INF-γ) production in whole blood culture (WBC) and IL-6 and IL-1β levels in the GCF were evaluated. Circulating levels of IL-6 and IL-1β (unstimulated) as well as GCF IL-1β were modestly lower in MDD patients, compared to the levels in age-matched controls (Mann–Whitney, p = 0.002, 0.0075, ANCOVA, p = 0.025, respectively). In the unstimulated group, there was no correlation between the levels of circulating IL-6 and GCF IL-6 (r = 0.07, p = 0.67), and between the levels of circulating IL-1β and the IL-1β level in the CGF (r = −0.08, p = 0.63). In the LPS stimulation group, there was no correlation between the levels of circulating levels of IL-6 and GCF IL-6 (r = 0. 02, p = 0.91) or between the circulating IL-1β and GCF IL-1β (r = 0.13, p = 0.42). We observed modest immunosuppression in MDD patients (evaluated by no stimulation whole blood culture [WBC]), especially in patients with melancholic depression, chronic depression, and severe depression.     

丙戊酸对大鼠急性脊髓损伤后神经功能恢复的影响及作用机制

目的:探讨丙戊酸(VPA)对大鼠脊髓损伤(SCI)后运动功能恢复的影响及作用机制。方法:60只雄性SD大鼠随机均分为3组:假手术组(C组)、损伤组(SCI组)和丙戊酸保护组(VPA组)。SCI组和VPA组采用改良Allen法制作大鼠T10 SCI模型。VPA组术后即刻及其后每12h皮下注射VPA 300mg/kg,至取材;C组和SCI组在相应时间点注射等体积的生理盐水。伤后6h,每组取5只大鼠处死取材,其余大鼠在伤后24h、48h和72h每组取5只先行后肢运动功能BBB评分,随后处死取材。切片后分别行HE染色观察脊髓组织病理变化,免疫荧光双标法在激光共聚焦显微镜下观察核因子κB(NF-κB)途径的激活状态,免疫组化法检测白介素1β(IL-1β)的表达。结果:C组大鼠各时间点BBB评分均为21分,VPA组和SCI组各时间点的评分均低于C组(P<0.05),但VPA组各时间点的评分均高于同时间点SCI组,在伤后48h和72h两组差异有显著性(P<0.05)。病理检查显示C组脊髓组织形态正常,VPA组和SCI组伤后6h损伤中央区即可见明显出血灶,灰质中神经元肿胀坏死,白质中神经纤维肿胀;伤后24h、48h出血灶界限更明显,并可见空洞形成和炎症细胞浸润;伤后72h上述病理变化仍明显;VPA组各时间点的病理变化与SCI组相似,但炎症细胞浸润减少。C组偶见或未见NF-κB核阳性细胞和IL-1β表达,与C组相比,SCI组和VPA组NF-κB核阳性细胞百分比和IL-1β表达量从伤后6h即显著性增高,24h达高峰,以后逐渐减少,72h仍显著性高于C组(P<0.05);VPA组各时间点NF-κB核阳性细胞百分比和IL-1β表达量均低于同时间点SCI组(P<0.05)。结论:VPA可促进大鼠SCI后运动神经功能恢复,其机制可能与抑制炎症反应有关。     

抑制肝癌细胞β-catenin表达能降低缺氧诱导的侵袭转移潜能

目的 研究β-catenin表达对缺氧环境中肝癌细胞侵袭转移潜能的影响.方法 利用100 μmol/L氯化钴处理高转移性MHCC97肝癌细胞模拟体外缺氧;将红色荧光标记的上述细胞(MHCC97-R)行肝脏原位种植并肝动脉结扎,构建体内缺氧模型.在此基础上,以RNAi技术敲除上述细胞内β-catenin基因,观察其对缺氧环境中肝癌细胞侵袭、转移能力的影响.结果 缺氧抑制MHCC97肝癌细胞增殖及MHCC97-R移植瘤生长,但增加其体外侵袭及体内转移.敲除β-catenin不能进一步加强缺氧对细胞增殖的抑制效应,但可明显减少由缺氧诱导的侵袭、转移.结论 缺氧环境中,肝癌细胞增强的侵袭转移潜能与β-catenin功能相关.     

转录抑制因子Snail表达与胃癌Lauren分型的关系研究

目的探讨转录抑制因子Snail表达与胃癌Lauren分型的关系。方法Western印迹检测肠型胃癌细胞系（N87）和弥漫型胃癌细胞系（AGS）中Snail和上皮型E钙黏蛋白（E-cadherin）的表达。将糖原合酶激酶．3B（GSK-3B）质粒转染胃癌细胞系,检测Snail和E-cadherin的表达变化。收集2000年2月至2005年12月间在复旦大学附属中山医院行胃癌根治术的77例术后组织标本．采用免疫组织化学染色检测Snail在胃癌组织中表达．并分析其与胃癌Lauren分型之间的关系。结果Snail在N87中低表达,在AGS中高表达;E-cadherin表达与Snail相反。转染GSK-3B后,胃癌细胞Snail表达显著下调,E-cadherin表达显著上调（P〈0．01）。使用不同浓度的GSK-3B抑制剂氯化锂处理后．胃癌细胞Snail表达显著上调,且具有明显浓度依赖性（P〈0．01）。21例肠型胃癌中Snail低表达16例,高表达5例;56例弥漫型胃癌中Snail低表达21例,高表达35例;肠型胃癌中Snail表达明显弱于弥漫型,差异有统计学意义（P〈0．01）。结论Snail的表达与胃癌Lauren分型有关．是一种潜在的确定胃癌分型的分子标志物。