应激与海马神经元凋亡

自1936年加拿大学者Selye首次提出应激理论以来,随着医学模式的转变,探索应激对机体健康的影响成为研究的热点。目前研究病理性应激主要形成以下理论:(1)应激造成机体应激反应的主要特征是增强的神经内分泌反应,其中以下丘脑-垂体-肾上腺皮质(HPA)轴终端的肾上腺皮质分泌的应激     

十溴联苯醚致大鼠学习记忆及海马神经元氧化损伤和凋亡研究

目的 观察十溴联苯醚(BDE-209)对成年大鼠学习记忆及海马神经元氧化应激和凋亡的影响.方法 将96只SD雄性大鼠随机分为溶剂对照组、BDE-209低(250 mg/kg)、中(500 mg/kg)、高(1 000 mg/kg)剂量组,每天灌胃1次,持续30 d.用Morris水迷宫检测学习记忆功能,化学比色法测定大鼠海马组织总抗氧化能力(T-AOC)、谷胱甘肽转移酶( GST)、超氧化物歧化酶(SOD)、丙二醛(MDA)的水平,考马斯亮蓝法测定蛋白水平,末端标记(TUNEL)法检测海马CA1区神经元凋亡.结果 与对照组比较,BDE-209染毒组大鼠的平均逃避潜伏期明显增加、空间搜索有效策略百分比和穿越平台的次数明显减少(P＜0.05);且随染毒剂量的增加,BDE-209各组的平均逃避潜伏期明显增加、空间搜索有效策略百分比和穿越平台的次数明显减少(P＜0.05).BDE-209染毒组海马T-AOC、GST和SOD的活力明显低于对照组,MDA水平明显高于对照组(P＜0.05);并随染毒剂量的增加各染毒组T-AOC、GST和SOD的活力明显降低,MDA水平明显增加(P＜0.05).TUNEL法检测结果显示BDE-209染毒组较对照组染色深,凋亡细胞数明显增加(P＜0.05);BDE-209染毒组随染毒剂量的增加染色加深,凋亡细胞增加(P＜0.05).结论 BDE-209致成年大鼠学习记忆能力下降可能与海马神经元细胞氧化损伤和凋亡有关.     

芍药苷抑制醋酸铅诱导大鼠海马神经元凋亡的机制

目的:探讨芍药苷对醋酸铅诱导海马神经元凋亡的影响及潜在机制。方法:于2020年9月,从胎鼠中分离培养原代海马神经元细胞,并利用细胞免疫荧光法进行鉴定。MTT法测定细胞活力确定醋酸铅诱导海马神经元凋亡浓度及时间,芍药苷细胞毒性研究评价芍药苷浓度及其对醋酸铅诱导海马神经元凋亡的影响。依据结果选取不同浓度芍药苷干预海马神经元...     

十溴联苯醚对大鼠学习记忆及海马神经元影响

目的 探讨十溴联苯醚(BDE-209)对成年大鼠学习记忆及海马神经元的影响.方法 将48只SD成年大鼠随机分为溶剂对照组、BDE-209低、中、高(250,500,1 000 mg/kg)剂量组,每天灌胃1次,持续30 d;用Morris水迷宫测试学习记忆,电镜观察海马神经元结构.结果 对照组和BDE-209低、中、高剂量组穿越平台次数分别为(12.63±2.48)、(9.90±1.75)、(7.26±1.48)、(4.72±1.76)次,在平台象限停留时间分别为(52.92±7.78)、(31.89±5.97)、(24.82±6.65)、(18.25±5.23)s,差异具有统计学意义(P＜0.05),平均逃避潜伏期随染毒剂量的增加明显延长(P＜0.05);与对照组比较,BDE-209染毒组海马神经元均有不同程度损害,线粒体肿胀,粗面内质网和高尔基复合体扩张、细胞核染色质异常聚集及均匀化,神经元突触结构不清楚.结论:BDE-209可致成年大鼠海马神经元结构及其功能损伤,降低学习记忆能力.     

内质网应激诱导的细胞凋亡与心肌缺血再灌注损伤

缺血再灌注损伤是心血管疾病中常见的病理生理过程,在心血管疾病的发生、发展中起着重要的作用。缺血再灌注损伤确切的机制还不完全清楚,实验证实细胞凋亡在心肌缺血再灌注损伤的病理生理过程中发挥着重要的作用.     

内质网应激诱导的细胞凋亡与心肌缺血再灌注损伤

缺血再灌注损伤是心血管疾病中常见的病理生理过程,在心血管疾病的发生、发展中起着重要的作用。缺血再灌注损伤确切的机制还不完全清楚,实验证实细胞凋亡在心肌缺血再灌注损伤的病理生理过程中发挥着重要的作用.     

细胞内钙离子在高温诱导海马神经元凋亡中的作用机制

目的探讨Ca2+在高温诱导海马神经元凋亡中的作用,为丹曲林钠在热致脑损伤疾病中的应用提供实验依据。方法通过体外建立高温诱导原代培养的海马神经元凋亡模型,应用Ca2+特异性阻断剂丹曲林钠,观察其对神经元凋亡率、细胞内Ca2+荧光强度及其动态变化的影响。结果丹曲林钠能够明显降低高温处理后海马神经元的凋亡率;42℃处理并加入丹曲林钠组的扫描结果显示,Ca2+荧光强度为107.35±6.0,较正常培养的细胞内Ca2+荧光强度(159.12±33.8)明显降低,加入丹曲林钠20～25s后Ca2+浓度即开始下降,约50s后下降至最低值,然后稳定于低于原来基线的水平。结论丹曲林钠在高温诱导的海马神经细胞凋亡中具有重要的保护作用,在预防热致脑损伤疾病中具有一定的应用价值。     

内质网应激途径在天花粉蛋白诱导的Hela细胞凋亡中的作用

目的:探讨内质网应激在天花粉蛋白诱导人宫颈癌Hela细胞凋亡过程中的作用,进一步分析天花粉蛋白诱导凋亡的作用机制。方法:以不同浓度天花粉蛋白分别处理Hela细胞24、48、72 h后,采用MTT法检测细胞的活性,流式细胞术检测细胞凋亡,并用RT-PCR及实时荧光定量PCR分析天花粉蛋白对内质网应激标志分子GRP78和CALPAIN基因表达的影响。结果:天花粉蛋白对HeLa细胞的生长具有抑制作用,对照组Hela细胞体外生长活跃,实验组分别经20、40、80μg/ml TCS处理24、48、72 h后,细胞生长均不同程度地受到抑制,呈时间-浓度依赖性。流式细胞直方图上亦出现特征性的亚二倍体峰(sub-G1 peak),随着天花粉蛋白浓度的增加,内质网应激分子GRP78和CALPAIN的表达逐渐增强。结论:天花粉蛋白可诱导宫颈癌HeLa细胞发生凋亡,内质网应激作为细胞凋亡的重要途径参与了天花粉蛋白诱导的HeLa细胞凋亡。     

十溴联苯醚对小鼠学习记忆能力及海马NOS和NO的影响

目的探讨十溴联苯醚(PBDE-209)暴露对小鼠学习记忆能力的影响和可能机制。方法将18只4周龄雄性ICR小鼠随机分成3组,每组6只。分为溶剂对照组(DMSO组),低剂量染毒组(300 mg/kg),高剂量染毒组(500 mg/kg),每周染毒6次,连续染毒6周。染毒第6周利用Morris水迷宫测定小鼠学习记忆能力(期间继续给药),染毒6周结束后处死老鼠,取一侧海马进行HE染色观察海马组织形态学改变,另一侧海马测定组织NOS活性和NO含量。结果小鼠海马组织的病理切片结果显示:染毒组海马组织CA1区细胞排列紊乱,高剂量染毒组的细胞紊乱更明显。Morris水迷宫实验结果显示,高剂量染毒组和低剂量染毒组小鼠找到平台的平均潜伏期分别为(64.322±4.419)s和(50.912±4.419)s,长于对照组的(23.183±4.419)s(P<0.05)。探索实验结果显示,高剂量染毒组穿越平台次数为(1.83±0.753)次,明显少于对照组的(3.67±0.516)次(P<0.05)。高剂量染毒组和低剂量染毒组小鼠海马NOS活性分别是(1.209±0.241)U/mg prot和(2.198±0.192)U/mg prot,低于对照组的(3.551±0.347)U/mg prot;NO含量分别为(0.099±0.012)μmol/mg prot和(0.325±0.027)μmol/mg prot,低于对照组的(0.544±0.020)μmol/mg prot(P<0.05)。结论 PBDE-209暴露可能抑制海马中NOS活性及NO含量,并影响小鼠学习记忆能力,其间关系值得进一步探讨。     

砷对原代培养海马神经元凋亡及突触素和生长相关蛋白GAP-43表达的影响

目的观察砷对原代培养海马神经元的细胞活性、凋亡及突触素(SYN)和生长相关蛋白GAP-43表达的影响。方法将原代培养的新生SD大鼠海马神经元分别暴露于含0.00、0.05、0.10、0.20、0.40μg/ml亚砷酸钠的培养基中培养24 h。检测神经元形态变化、细胞凋亡及SYN和GAP-43蛋白的表达水平。结果与对照组比较,0.10、0.20、0.40μg/ml亚砷酸钠染毒组大鼠海马神经元中神经网络丰富型神经元的构成比降低,海马神经元的凋亡率较高,SYN蛋白表达水平降低,各浓度亚砷酸钠染毒组大鼠海马神经元中GAP-43蛋白表达水平均降低,差异均有统计学意义(P0.05,P0.01)。且随着亚砷酸钠染毒浓度的升高,大鼠海马神经元的凋亡率呈上升趋势,SYN和GAP-43蛋白表达水平呈下降趋势。结论砷可诱导原代培养海马神经元凋亡,通过降低SYN和GAP-43蛋白表达而损伤其突触可塑性。     

PBDE-209致小鼠肝脏病理学改变及其氧化应激机制研究

目的 通过对小鼠进行十溴联苯醚(decabrominated diphenyl ether,PBDE-209)染毒,研究该物质对小鼠肝脏的毒性作用及其可能的氧化应激机制.方法 将24只小鼠随机分3组,即生理盐水组、PBDE-209低剂量组和高剂量组,每组8只,将小鼠按10ml/kg体重剂量经口灌胃染毒连续6周,观察各组小鼠肝脏组织形态学和超微结构改变,并测定小鼠各项生化指标.结果 染毒组小鼠血清谷丙转氨酶和谷草转氨酶水平均升高,与生理盐水组比较,差异有统计学意义.高、低剂量组小鼠肝脏组织丙二醛含量均高于生理盐水组,差异有统计学意义;高剂量组小鼠肝脏谷胱甘肽含量低于生理盐水组和低剂量染毒组,差异有统计学意义;高、低剂量组总超氧化物歧化酶活性低于生理盐水组,差异有统计学意义.光镜下观察染毒组小鼠肝脏出现肝细胞浊肿,胞浆内有细小脂质空泡,肝索排列发生改变,部分肝细胞模糊,空泡化显著;电镜下观察染毒组小鼠肝脏出现染色质浓缩聚合,线粒体膨胀,内质网增大.结论 PBDE-209可以引起肝脏组织脂质过氧化指标和组织形态学以及超微结构的改变.     

多溴联苯醚对SH-SY5Y细胞氧化应激及凋亡的影响

目的观察2,2’,4,4’-四溴联苯醚(PBDE-47)对人神经母细胞瘤SH-SY5Y细胞株氧化应激和凋亡的影响及活性氧在细胞凋亡中的作用。方法实验共分4组,PDDE-47终浓度为0、2、4、8μg/ml,分别作为对照组,低、中、高剂量组。用2、4、8μg/ml PBDE-47对培养的SH-SY5Y细胞染毒,24 h后检测细胞存活率、活性氧(ROS)水平、丙二醛(MDA)含量及凋亡率。结果与对照组比较,低剂量组细胞存活率略有上升,中、高剂量组细胞存活率明显降低,差异有统计学意义(P相似文献   

对羟基苯甲酸丁酯通过氧化应激导致人精子活力降低和凋亡增加

目的探究对羟基苯甲酸丁酯(BP)对人精子活力、氧化应激和细胞凋亡的影响及其机制。方法选取人精液样本20份,随机分为4组:对照组及BP低、中、高浓度组,每组5个平行样。与BP体外共培养4 h,BP染毒浓度分别为0、200、400和800μmol/L。观察精子活动力、细胞毒性、活性氧阳性细胞率和细胞凋亡率。结果BP低、中、高浓度组精子总活力[(26.44±7.83)%、(32.79±2.90)%和(10.51±5.88)%]均低于对照组[(47.67±3.93)%],差异有统计学意义(P0.05)。与对照组相比,BP低、中、高浓度组精子存活率分别为(63.36±9.08)%、(49.72±7.15)%和(29.91±5.93)%。BP低、中、高浓度组活性氧阳性细胞率[(24.67±0.50)%、(54.50±3.40)%和(59.93±3.47)%]高于对照组[(8.63±0.57)%],差异有统计学意义(P0.05),晚期精子凋亡率[(11.8±1.74)%、(12.87±0.25)%和(14.60±0.87)%]高于对照组[(9.63±1.00)%],差异有统计学意义(P0.05)。精子活性氧的水平和晚期凋亡率均与精子的总活力呈负相关,r分别为-0.727和-0.688(P0.05)。结论对羟基苯甲酸丁酯具有细胞毒性,能够降低精子活动能力,促进精子活性氧的生成和细胞凋亡。     

氧化应激与细胞凋亡关系的研究进展

大量研究表明 ,氧化应激可导致细胞凋亡。目前对这一现象有四种解释 :ROS活化核转录因子KB并诱导核转录因子 -KB表达 ,导致细胞凋亡 ;线粒体介导的细胞凋亡 ;ROS导致DNA损伤 ,激活P5 3诱导细胞凋亡及ROS激活SAPK通路介导细胞凋亡。但从总体上看 ,其分子机制还不十分清楚 ,有待进一步研究     

Ultrafine particulate pollutants induce oxidative stress and mitochondrial damage

The objectives of this study were to determine whether differences in the size and composition of coarse (2.5-10 micro m), fine (< 2.5 microm), and ultrafine (< 0.1 microm) particulate matter (PM) are related to their uptake in macrophages and epithelial cells and their ability to induce oxidative stress. The premise for this study is the increasing awareness that various PM components induce pulmonary inflammation through the generation of oxidative stress. Coarse, fine, and ultrafine particles (UFPs) were collected by ambient particle concentrators in the Los Angeles basin in California and used to study their chemical composition in parallel with assays for generation of reactive oxygen species (ROS) and ability to induce oxidative stress in macrophages and epithelial cells. UFPs were most potent toward inducing cellular heme oxygenase-1 (HO-1) expression and depleting intracellular glutathione. HO-1 expression, a sensitive marker for oxidative stress, is directly correlated with the high organic carbon and polycyclic aromatic hydrocarbon (PAH) content of UFPs. The dithiothreitol (DTT) assay, a quantitative measure of in vitro ROS formation, was correlated with PAH content and HO-1 expression. UFPs also had the highest ROS activity in the DTT assay. Because the small size of UFPs allows better tissue penetration, we used electron microscopy to study subcellular localization. UFPs and, to a lesser extent, fine particles, localize in mitochondria, where they induce major structural damage. This may contribute to oxidative stress. Our studies demonstrate that the increased biological potency of UFPs is related to the content of redox cycling organic chemicals and their ability to damage mitochondria.     

Effects of decabrominated diphenyl ether (PBDE-209) in regulation of growth and apoptosis of breast, ovarian, and cervical cancer cells

Background: Polybrominated diphenyl ethers (PBDEs), commonly used in building materials, electronics, plastics, polyurethane foams, and textiles, are health hazards found in the environment.Objective: In this study we investigated the effects of PBDE-209, a deca-PBDE, on the regulation of growth and apoptosis of breast, ovarian, and cervical cancer cells as well as the underlying protein alterations.Methods: We used MCF-7 and MCF-7/ADR (multidrug-resistant MCF-7) breast cancer cell lines, the HeLa cervical cancer cell line, the OVCAR-3 ovarian cancer cell line, and the normal CHO (Chinese hamster ovary) cell line to assess the effects of PBDE-209 using cell viability, immunofluorescence, and flow cytometric assays. Western blot assays were used to detect changes in protein expression. To assess the effects of PBDE-209 on apoptosis, we used the protein kinase Cα (PKCα) inhibitor Gö 6976, the extracellular signal-regulated kinase (ERK) inhibitor PD98059, and tamoxifen.Results: Our data indicate that PBDE-209 increased viability and proliferation of the tumor cell lines and in CHO cells in a dose- and time-dependent manner. PBDE-209 also altered cell cycle distribution by inducing the S phase or G₂/M phase. Furthermore, PBDE-209 partially suppressed tamoxifen-induced cell apoptosis in the breast cancer cell lines (MCF-7 and MCF-7/ADR) but suppressed Gö 6976- and PD98059-induced apoptosis in all cell lines. At the molecular level, PBDE-209 enhanced PKCα and ERK1/2 phosphorylation in the cell lines.Conclusions: Our data demonstrate that PBDE-209 is able to promote proliferation of various cancer cells from the female reproductive system and normal ovarian CHO cells. Furthermore, it reduced tamoxifen, PKCα, and ERK inhibition-induced apoptosis. Finally, PBDE-209 up-regulated phosphorylation of PKCα and ERK1/2 proteins in tumor cells and in CHO cells.     

Evidence of oxidative stress in American kestrels exposed to electromagnetic fields.

Exposure to electromagnetic fields (EMFs) alters melatonin, behavior, growth, and reproduction of captive American kestrels (Falco sparverius), particularly of males. EMF exposure is a "possible" human carcinogen and associated with some neurodegenerative diseases. Oxidative stress contributes to cancer, neurodegenerative diseases, and immune disorders. We tested whether EMF exposure elicits an avian immune response and alters oxidative stress levels. Captive male kestrels were bred under control or EMF conditions equivalent to those experienced by wild kestrels. Short-term EMF exposure (one breeding season) suppressed plasma total proteins, hematocrits, and carotenoids in the first half of the breeding season. It also suppressed erythrocyte cells and lymphocyte proportions, but elevated granulosa proportions at the end of the breeding season. Long-term EMF exposure (two breeding seasons) suppressed hematocrits in the first half of the reproductive period too. Results indicate that only short-term EMF birds experience an immune response, particularly during the early half of the breeding season. The elevation of granulocytes, and the suppression of carotenoids, total proteins, and previously melatonin in the same kestrels, signifies that the short-term EMF male kestrels had higher levels of oxidative stress, due to an immune response and/or EMF exposure. Long-term EMF exposure may be linked to higher levels of oxidative stress through EMF exposure only.