Bcl-2家族参与β-淀粉样蛋白对PC12细胞的致凋亡作用

目的:研究bcl-2家族(主要是bcl-xl和bax)基因及相关蛋白是否参与水溶性淀粉样蛋白对培养的大鼠嗜铬细胞瘤细胞的毒性作用.方法:应用电镜和DNA电泳判断细胞损伤途径,应用RT-PCR,免疫细胞化学和免疫印迹判断bcl-2家族及其相关蛋白是否参与淀粉样蛋白的损伤作用.结果:10 μmol/L Aβ25-35作用24 h后,电镜和DNA电泳均显示Aβ25-35可以导致PC12细胞凋亡;RT-PCR表明药物作用后6 h,bcl-xl mRNA表达量减少而bax mRNA表达量增加;免疫印迹和免疫细胞化学结果显示药物作用后24h,Bax蛋白增加而Bcl-xl无明显改变.结论:水溶性淀粉样蛋白可以导致神经细胞凋亡,bcl-2家族参与了作用环节,对阿尔茨海默病的发病起着重要的作用.     

β-淀粉样肽(25-35)对PC12细胞前列腺凋亡反应蛋白-4和bcl-2基因表达的影响

目的观察β-淀粉样肽（25-35）（β-amyloid peptide 25-35，Aβ-25-35）诱导PC12细胞凋亡及对前列腺凋亡反应蛋白-4（prostate apoptosis response-4，par-4）和bcl-2基因表达的影响。方法采用MTT比色法分析细胞存活率，Hoechst33258-PI荧光染色观察细胞核凋亡的形态学改变，RT-PCR检测par-4和bcl-2基因mRNA表达变化，Western blot检测Par-4和Bcl-2蛋白表达变化。结果 随Aβ23-35浓度的增加，PC12细胞存活率降低，荧光染色可见细胞核固缩、核碎裂，par-4 mRNA及蛋白表达增加，bcl-2 mRNA及蛋白表达降低。结论 在Aβ25-35诱导PC12细胞凋亡过程中Par-4和Bcl-2蛋白分子可能起重要作用。     

G422胶质瘤冷冻后细胞凋亡及相关基因表达的研究

目的：探讨冷冻杀伤肿瘤细胞的分子机制。方法；建立小鼠脑胶质瘤动物模型；用末端标记法（TUNEL）原位检测细胞凋亡，DNA琼脂糖电泳观察DNA梯形条带；用免疫组织化学ABC法检查bcl-2和bax表达。结果：不同冻融周期作用于G422胶质瘤后，在不同时间点、冷冻灶周边区的肿瘤细胞出现了形态学和DNA水平上的细胞凋亡变化，其峰值出现在冷冻后24-48h。重复冻融出现更多的凋亡细胞。不同冻融周期均引起冷冻灶周边区细胞bax上调，但对抑凋亡基因bcl-2表达无明显影响。结论：冷冻治疗可以诱导G422胶质瘤细胞凋亡，冷冻诱导的细胞凋亡由bax基因参与介导，而与bcl-2表达无关。诱导细胞凋亡可能 是冷冻杀伤肿瘤细胞的重要机制。     

水溶性β-淀粉样蛋白25-35片段诱致大鼠嗜铬细胞瘤细胞凋亡

目的　探讨β-淀粉样蛋白 ( Aβ)在形成淀粉样沉积前对体外培养的 PC1 2细胞的毒性作用。方法　应用流式细胞仪检测 Aβ的剂量依赖性毒性 ;应用 DNA琼脂糖凝胶电泳、DNA末端标记和电镜判断 Aβ损伤细胞的途径。结果　流式细胞仪检测发现随着 Aβ2 5 -35浓度的增加 ,PC1 2细胞的死亡率增加 ;加入 1 0 μmol/L Aβ2 5 -35 2 4 h后 ,经 TUNEL发现细胞核着色 ,并可见细胞核碎片 ;DNA琼脂糖凝胶电泳可见间隔 1 80～ 2 0 0 bp左右的梯度条带 ;电镜显示细胞核浓缩 ,胞浆内有空泡形成 ,胞浆内细胞器完好。结论　 Aβ在形成纤维状沉积前即对神经细胞有毒性作用 ,可促进神经细胞的凋亡。     

FoxM1抑制剂硫链丝菌素对髓母细胞瘤Daoy细胞增殖与凋亡的影响

目的 探讨FoxM1抑制剂硫链丝菌素对髓母细胞瘤Daoy细胞株增殖及凋亡的影响. 方法 体外常规培养髓母细胞瘤Daoy细胞株,CCK-8法检测0、1、1.5、2、3、5μmol/L硫链丝菌素作用24、48、72 h后细胞存活率的变化;实时定量聚合酶链反应(RT-PCR)、免疫印迹法分别检测0、1、1.5、2μmol/L硫链丝菌素作用48 h后细胞FxoMl mRNA和蛋白的表达,流式细胞仪检测细胞周期和凋亡,免疫印迹法检测凋亡相关蛋白Bcl-2、Bax的表达. 结果 CCK-8检测显示不同浓度硫链丝菌素作用后Doay细胞存活率下降,且呈浓度和时间依赖性,差异有统计学意义(P＜0.05).24、48、72 h的IC50分别为(2.1±0.15)、(1.69±0.11)、(1.39±0.1)μmol/L; RT-PCR和免疫印迹实验显示,与0 μmol/L硫链丝菌素组比较,1、1.5、2μmol/L硫链丝菌素组细胞FoxMl mRNA及蛋白水平下降,G2/M期细胞细胞比例和凋亡率升高,凋亡蛋白bax表达增加,抗凋亡蛋白bcl-2表达减少,且均呈浓度依赖性,差异有统计学意义(P＜0.05). 结论 FoxM1抑制剂硫链丝菌素可明显抑制Daoy细胞增殖,可能与阻滞细胞周期于G2/M期、改变bcl-2/bax表达诱发凋亡有关.     

壳寡糖对Hela细胞cyclin D1、bcl-xl和bcl-2 mRNA表达的影响

背景：研究表明壳寡糖具有抗肿瘤作用,但壳寡糖对cyclin D1、bcl-2和bcl-xl影响机制尚不清楚。 目的：观察壳寡糖抑制Hela细胞生长的作用,以及对细胞内cyclin D1、bcl-xl和 bcl-2 mRNA表达的影响。 方法：壳寡糖(0.1,0.5,1,2,5 g/L)刺激Hela细胞后,CCK8实验检测其对细胞生长的影响;运用实时荧光定量PCR方法在分子水平检测cyclin D1、bcl-xl和 bcl-2 mRNA在细胞中的表达情况。 结果与结论：壳寡糖可抑制Hela细胞的生长;随着壳寡糖的质量浓度由0.1 g/L增加至2 g/L,壳寡糖抑制cyclin D1,bcl-2,bcl-xl基因表达的作用也逐渐增强,在2 g/L时作用最强,但质量浓度过高时(5 g/L)抑制作用反而有所减弱。结果表明壳寡糖的抗肿瘤作用可能通过两方面进行：一方面壳寡糖可以抑制与细胞周期有关的cyclin D1 mRNA表达以抑制肿瘤细胞的增殖;另一方面壳寡糖可以抑制抗凋亡蛋白Bcl-2 和bcl-xl mRNA的表达以促进肿瘤细胞的凋亡;且对前者的作用强于后者。 关键词：荧光定量PCR;壳寡糖;Hela细胞;细胞周期蛋白 D1;bcl-xl;bcl-2 doi:10.3969/j.issn.1673-8225.2010.03.012     

重组pIRES-AD7c-NTP质粒的构建表达及其对PC12细胞凋亡的影响

目的构建重组pIRES-AD7c-NTP质粒,探究其对PC12细胞凋亡的影响。方法构建pIRESAD7c-NTP重组质粒,通过脂质体体外转染至PC12细胞内,RT-PCR检测凋亡相关蛋白bcl-2和bax的mRNA表达变化含量变化。结果成功构建pIRES-AD7c-NTP重组质粒并转染至PC12细胞内;重组质粒转染组出现了明显的细胞凋亡,流式细胞仪检测出典型凋亡峰;重组质粒转染组中bcl-2表达低于对照组,bax表达高于对照组。结论 AD7c-NTP重组质粒转染组PC12细胞内bcl-2/bax表达异常,说明AD7c-NTP增加凋亡促进蛋白的表达、同时减少凋亡抑制蛋白的表达,可见AD7c-NTP可导致神经细胞发生凋亡,为后续研究提供实验基础。     

骨骼肌细胞线粒体通透性转换孔及bcl-2和bax mRNA表达与运动

背景：运动影响骨骼肌细胞的凋亡,而线粒体途径是介导细胞凋亡的一个重要途径。 目的：研究运动对大鼠骨骼肌线粒体通透性转换孔、凋亡调控基因bcl-2和bax表达的影响。 方法：将24只成年雄性SD大鼠随机分为3组：对照组正常饲养,6周游泳训练组进行6周的游泳训练,每周6次,一次性游泳力竭组于第6周进行一次力竭性游泳运动。应用紫外分光光度仪检测各组大鼠骨骼肌线粒体通透性转换孔的开放情况,应用RT-PCR测定大鼠骨骼肌bcl-2和bax mRNA的表达。 结果与结论：与对照组比较,6周游泳训练组大鼠骨骼肌线粒体通透性转换孔的开放程度变化不明显,bcl-2 mRNA的表达显著增加,bax mRNA的表达显著减少,bcl-2/bax mRNA比值显著增大(P < 0.01)。与对照组比较,一次性游泳力竭组大鼠骨骼肌线粒体通透性转换孔开放程度明显增加(P < 0.01),bcl-2 mRNA的表达显著减少,bax mRNA的表达显著增加,bcl-2/bax mRNA比值显著减小(P < 0.01)。说明运动训练可通过改变线粒体通透性转换孔的开放、调节bcl-2/bax表达,调控骨骼肌细胞凋亡。     

2002/原花青素对β-淀粉样肽（25-35）诱导去血清培养PC12细胞细胞周期分布的影响

目的 探讨原花青素 (Procyanidins,PC) 对β-淀粉样肽（25-35）[βamyloid peptide -(25-35),Aβ25-35] 诱导去血清培养PC12细胞的凋亡及细胞周期分布的影响。方法 流式细胞仪检测细胞周期分布情况及细胞凋亡率;RT-PCR 检测 p53基因 mRNA 表达;Western blot检测 P53蛋白表达。 结果 30mg/L PC预处理 PC12 细胞 1 h ,可降低Aβ25-35引起的去血清培养PC12细胞凋亡率,逆转Aβ25-35引起的去血清培养PC12细胞的细胞周期S期阻滞,降低 p53 mRNA及P53蛋白表达。 结论 PC可对抗Aβ25-35 诱导的去血清培养 PC12 细胞的凋亡及细胞周期S期阻滞,其机制可能与下调p53基因表达有关。     

创伤性股骨头缺血坏死过程中凋亡调控基因bcl-2、bax的表达及意义

背景：由于骨细胞是股骨头的主要功能细胞,因此股骨头中骨细胞的凋亡及影响凋亡的因子已经成为目前探讨缺血性股骨头坏死发病机制的研究热点。 目的：观察兔股骨头缺血坏死过程中凋亡调控基因bcl-2、bax 的表达变化,探讨股骨头缺血坏死的发病机制。 设计、时间及地点：动物观察试验,于2007-12/2008-09在遵义医学院珠海校区中心实验室完成。 材料：35只新西兰白兔随机分为对照组和实验组(缺血后3,6,12,24,48,96 h)共7组,每组5只。 方法：实验组采用开放手术中断兔股骨头血供致股骨头缺血坏死;对照组动物仅进行皮肤切开和肌肉分离至关节囊的手术。在缺血的不同时间段对股骨头内骨细胞以及Bcl-2、Bax两种蛋白进行测试及比较。 主要观察指标：应用苏木精-伊红染色,免疫组织化学(ABC法)来观测股骨头缺血后3,6,12,24,48,96 h股骨头内骨细胞陷窝变化及Bcl-2、Bax蛋白表达的变化情况。 结果：缺血12 h内苏木精-伊红染色见骨细胞变化较少,48 h出现部分骨细胞和成骨细胞消失,96 h空骨陷窝出现百分比明显高于48 h和对照组的 (P < 0.01)。Bcl-2在缺血后3 h开始出现阳性表达,缺血后12 h出现高峰,然后缓慢下降;Bax在缺血后3 h开始出现阳性表达,高峰出现在缺血后24 h;bcl-2/bax在24 h最小,然后逐渐升高。 结论：创伤性股骨头缺血坏死过程中凋亡基因bcl-2、bax表达变化说明其参与了股骨头细胞凋亡及股骨头缺血坏死过程,结合bcl-2/bax比率变化显示bcl-2、bax在缺血性股骨头坏死中通过调控骨细胞凋亡起作用。     

Neuroimaging in epilepsy in tropics

Epilepsy is a major public health problem in many tropical countries. Also, some of the tropical diseases are major contributors to the higher prevalence of epilepsy in these countries. The etiologic factors responsible for epilepsy in these countries are quite different from those in the developed world. This article discusses the etiologic factors and neuroimaging of epilepsy in light of the conditions in these tropical countries.     

癫痫与抑郁关系的研究进展

抑郁是癫痫患者中常见的精神障碍,严重地影响了患者的生活质量。传统的观点认为癫痫患者因为存在着诸多社会学问题易出现抑郁倾向,癫痫和抑郁是单向的联系,但大量的研究已经证明癫痫和抑郁之间存在双向的联系,一种异常状态的存在可能易转化为另一种异常状态的发展。癫痫和抑郁存在着共同的发病机制。本文主要就癫痫和抑郁的双向联系以及抗抑郁药物在癫痫患者中的应用进行阐述。     

Sudanophilic lipid accumulation in astrocytes in periventricular leukomalacia in monkeys

Summary Sudanophilic lipid accumulation is a characteristic feature of periventricular leukomalacia (PVL) of infants. At least two types of lipid-containing cells have been identified, one being the macrophage, the other the pre-myelin glial cell. A third type of lipid-containing cell has been seen in two monkeys with spontaneous PVL. Electron microscopically this cell appears to be an astrocyte. This probably represents a reaction of the astrocyte to hypoxia and may be the equivalent of the hypertrophic astrocytes found in human infants.Supported in part by NIH grant HDO 8633 and the Regional Primate Research Center Grant RR-00166     

Increase in cathepsin D activity in rat brain in aging

Cathepsin D-like activity in homogenates of five brain areas of 3-month-old and 24-month-old Fischer 344 rats was measured. With hemoglobin as substrate at pH 3.2, more than 90% of the activity was inhibited by pepstatin. In each area studied, activity was more than twice as high in the old rat brain: 140-160% higher in the cortex, cerebellum, pons-medulla, and striatum and 90-100% higher in the hippocampus and spinal cord. The greatly increased metabolic capacity in the absence of an increase in protein turnover may have a role in age-related pathological degeneration in the brain.     

Characteristics of nociceptors in the periodontium--an in vitro study in rats

Recent studies have indicated that nociceptors can be classified into various types according to their physiological properties. These studies have clarified that the frequency distribution of various nociceptor types is different among body sites and animal species. In the present study, we investigated the physiological properties of rat's periodontal nociceptors in an in vitro jaw-nerve preparation. Responses were recorded from functional single filaments in the inferior alveolar nerve. To determine the nociceptor type, calibrated von Frey filaments, heat, and bradykinin (BK) stimuli were used. We found five subtypes of nociceptors in the periodontal ligaments of the lower incisor: Adelta-high threshold mechanonociceptors (Adelta-HTM, n=28), Adelta-mechanoheat nociceptors (Adelta-MH, n=6), Adelta-polymodal nociceptors (Adelta-POLY, n=26), C-high threshold mechanonociceptors (C-HTM, n=3) and C-polymodal nociceptors (C-POLY, n=4). Most nociceptors were Adelta-innervated, while only a small number of C-innervated nociceptors were found. The present results suggest that periodontal nociceptors transmit mainly fast pain, and may thus play a role in rapid detection of injure-related stimuli during mastication.     

Gender in Voice Perception in Autism

Deficits in the perception of social stimuli may contribute to the characteristic impairments in social interaction in high functioning autism (HFA). Although the cortical processing of voice is abnormal in HFA, it is unclear whether this gives rise to impairments in the perception of voice gender. About 20 children with HFA and 20 matched controls were presented with voice fragments that were parametrically morphed in gender. No differences were found in the perception of gender between the two groups of participants, but response times differed significantly. The results suggest that the perception of voice gender is not impaired in HFA, which is consistent with behavioral findings of an unimpaired voice-based identification of age and identity by individuals with autism. The differences in response times suggest that individuals with HFA use different perceptual approaches from those used by typically developing individuals.     

Defects in Bioenergetic Coupling in Schizophrenia

Synaptic neurotransmission relies on maintenance of the synapse and meeting the energy demands of neurons. Defects in excitatory and inhibitory synapses have been implicated in schizophrenia, likely contributing to positive and negative symptoms as well as impaired cognition. Recently, accumulating evidence has suggested that bioenergetic systems, important in both synaptic function and cognition, are abnormal in psychiatric illnesses such as schizophrenia. Animal models of synaptic dysfunction demonstrated endophenotypes of schizophrenia as well as bioenergetic abnormalities. We report findings on the bioenergetic interplay of astrocytes and neurons and discuss how dysregulation of these pathways may contribute to the pathogenesis of schizophrenia, highlighting metabolic systems as important therapeutic targets.     

Ethnic disparities in problem behaviour in adolescence contribute to ethnic disparities in social class in adulthood

BACKGROUND: It is important for prevention of social class disparities to know how ethnic disparities in social class arise among migrant children. We contribute to this understanding by examining the role of problem behaviour in adolescence. METHODS: Prospective observational study with 753 Dutch native and 217 Turkish migrant adolescents (11-18 year) followed for 10 years. Internalising and externalising problems were assessed in adolescence and employment status and occupational level were assessed in adulthood. The difference in odds ratios (OR) before and after adjustment for internalising and externalising problems was an indication of the predictive value of disparities in internalising and externalising problems for the development of social class disparities. RESULTS: A total of 135 (62%) of the Turkish and 602 (80%) of the Dutch adults were employed. Internalising and externalising problems were not associated with employment status. Of the employed, 65 (48%) Turkish and 179 (30%) Dutch adults worked in low-level occupations (p < 0.0001). Internalising and externalising problems were associated with both ethnicity and occupation. The OR for low-level occupation for Turkish adults was 1.78 (1.19-2.65), indicating ethnic disparities. Adjustment for internalising problems lowered the OR with 36% to 1.50 (0.97-2.31), and adjustment for externalising problems lowered it with 8% to 1.72 (1.15-2.57). Findings were similar for men and women and did not vary by age. CONCLUSIONS: Ethnic disparities in occupational level in adulthood could partly be attributed to disparities in mental health between Turkish migrants and Dutch natives in adolescence. Prevention of ethnic disparities in mental health at young age may therefore also contribute to the prevention of occupational differences in adulthood.     

Progress in neuroprotection in Parkinson's disease

Slowing or aborting the progress of neurodegeneration in Parkinson's disease (PD) remains the most important unmet need of this disorder. There are several recent developments in trial design and also in drugs under investigation for possible neuroprotective effect. Emphasis has been placed on clinical as opposed to imaging end-points and these include change in a clinical rating scale, e.g. United Parkinson's disease Rating Scale (UPDRS), or time to additional therapy. The introduction of the delayed-start, or wash-in, trial design adds an additional dimension to drug evaluation for neuroprotection. Compounds that have been recently tested in clinical trial include the monoamine oxidase-B inhibitor rasagiline, the anti-apoptotic agents TCH346 and CEP1347, and the promitochondrial agent creatine. The dopamine agonists have been evaluated for a neuroprotective effect using imaging end-points. Perhaps the most important and simplest concept for neuroprotection has been the theory that early dopaminergic support for the degenerating dopaminergic system per se provides significant long-term clinical benefit for PD patients.     

Changes in parasympathetic system in medulla oblongata in male pigs in the course of tachycardia-induced cardiomyopathy

Background

Autonomic imbalance constituting a fundamental feature of heart failure (HF) has been assessed mainly at the periphery. Changes in the functioning of autonomic centers in the brain remain unclear. We investigated the molecular elements of parasympathetic system, i.e. α7 nicotinic acetylcholine receptor (α7nAChR) and enzymes metabolizing acetylcholine (acetylcholinesterase, AChE, choline acetyltransferase, ChAT) in medulla oblongata (MO) of male pigs with chronic tachycardia-induced cardiomyopathy.

Methods

The mRNA levels of AChE, ChAT, α7nAChR and X-box binding protein 1 (spliced form, XBP1s) in MO were analyzed using qPCR, AChE and ChAT activities using spectrophotometry, proteasome activity using fluorometry, and the protein level of α7nAChR using Western blotting.

Results

The development of systolic HF was accompanied by an increase in circulating catecholamines, a decrease in the AChE and α7nAChR mRNA in MO, an increase in AChE activity (all p < 0.05), and no change in either the mRNA or activity of ChAT. Both circulating catecholamine levels and AChE activity were inversely related to systolic function of left myocardial ventricle (p < 0.05). The level of α7nAChR protein in MO and its cytoplasmatic fraction were higher in pigs with moderate and severe HF as compared to the other animals (p < 0.01). There was no difference in proteasome activity in MO between diseased and healthy animals, whereas the XBP1s mRNA decreased during HF progression (p < 0.05).

Conclusions

Molecular elements of parasympathetic system are changed within the medulla oblongata during the progression of systolic non-ischemic heart failure in male pigs, indicating a functional link between MO and heart in HF.