JTE-522-induced apoptosis in human gastric adenocarinoma cell line AGS cells by caspase activation accompanying cytochrome C release,membrane translocation of Bax and loss of mitochondrial membrane potential

AIM: To investigate the role of the mitochondrial pathway in JTE-522-induced apoptosis and to investigate the relationship between cytochrome C release, caspase activity and loss of mitochondrial membrane potential (Deltapsim). METHODS: Cell culture, cell counting, ELISA assay, TUNEL, flow cytometry, Western blot and fluorometric assay were employed to investigate the effect of JTE-522 on cell proliferation and apoptosis in AGS cells and related molecular mechanism. RESULTS: JTE-522 inhibited the growth of AGS cells and induced the apoptosis. Caspases 8 and 9 were activated during apoptosis as judged by the appearance of cleavage products from procaspase and the caspase activities to cleave specific fluorogenic substrates. To elucidate whether the activation of caspases 8 and 9 was required for the apoptosis induction, we examined the effect of caspase-specific inhibitors on apoptosis. The results showed that caspase inhibitors significantly inhibited the apoptosis induced by JTE-522. In addition, the membrane translocation of Bax and cytosolic release of cytochrome C accompanying with the decrease of the uptake of Rhodamin 123, were detected at an early stage of apoptosis. Furthermore, Bax translocation, cytochrome C release, and caspase 9 activation were blocked by Z-VAD.fmk and Z-IETD-CHO. CONCLUSION: The present data indicate a crucial association between activation of caspases 8, 9, cytochrome C release, membrane translocation of Bax, loss of Deltapsim and JTE-522-induced apoptosis in AGS cells.

Mitochondrial membrane stabilization by Angelica sinensis polysaccharide in murine aplastic anemia

In order to investigate the mechanism of mitochondrial membrane stabilization by Angelica sinensis polysaccharide (ASP) in murine aplastic anemia (AA).ICR mice were randomly divided into control, AA and ASP-treated groups. The AA group mice were treated with 60Coγand intraperitoneal injections of cyclophosphamide and chloramphenicol. The control animals were treated with lead shielding irradiation and saline injection. The treated AA mice were fed with ASP for 2 wk. Mitochondrial ultrastructure of the bone marrow was observed by transmission electron microscopy, and the transmembrane potential of bone marrow-nucleated cells (BMNC)was examined by fluorescence spectrophotometry. The Cox and MDH contents of the medium were also studied in the three groups.The mitochondrial number and transmembrane potential of BMNC in the bone marrow decreased in the AA group as compared to the control group, but improved in the ASP-treated group as compared to the AA group. Complete mitochondrial cleavage in the ASP-treated group was significantly delayed (P<0.05) as compared to the AA group. We conclude that ASP might improve mitochondrial membrane stabilization, and suppress the downregulation of transmembrane potential and apoptosis of BMNC in AA.

黄连素通过诱导线粒体自噬干预呼吸道合胞病毒感染HEp-2细胞的作用机制

目的探讨黄连素(berberine,BE)对呼吸道合胞病毒(respiratory syncytial virus,RSV)感染HEp-2细胞的影响及相关机制。方法将HEp-2细胞感染RSV,并用BE处理。CCK-8实验检测HEp-2细胞存活率;Western blot检测HEp-2细胞NLRP3、ASC、caspase-1、PINK1、Parkin、Beclin1、p62、LC3Ⅰ、LC3Ⅱ、BNIP3蛋白表达;ELISA检测HEp-2细胞IL-1β分泌水平;流式细胞术检测HEp-2细胞的凋亡率和线粒体膜电位;MitoSOX染色检测HEp-2细胞线粒体ROS(mtROS);免疫荧光染色检测HEp-2细胞线粒体-自噬小体共定位;环孢素A进行验证实验。结果BE能提高RSV感染HEp-2细胞的活性、降低凋亡率(P<0.05),并降低NLRP3炎性小体活化水平和IL-1β水平(P<0.05);BE通过提高线粒体膜电位和ATP水平、降低mtROS改善线粒体功能;同时,BE促进RSV感染细胞中线粒体-自噬小体共定位,诱导PINK1/Parkin和BNIP3介导线粒体自噬;环孢素A加重了RSV的感染。结论BE对RSV感染的HEp-2细胞具有保护作用,其机制可能与BE通过诱导PINK1/Parkin和BNIP3介导的线粒体自噬,进而抑制mtROS产生改善线粒体功能,并抑制NLRP3炎性小体活化有关。

REEP5在川崎病中的表达及通过影响线粒体功能对血管内皮细胞早期凋亡的影响

目的探讨REEP5在川崎病患儿中的表达,以及其通过影响线粒体功能对血管内皮早期细胞凋亡的影响。方法选取2020年1月至2023年6月于唐山中心医院就诊的69例川崎病患儿为研究对象,根据是否发生冠状动脉损伤分为冠状动脉损伤组(33例)和非冠状动脉损伤组(36例),选取30例健康体检儿童为健康对照组。酶免疫吸附法检测血清REEP5表达,检测细胞凋亡、血管生成能力、线粒体功能及细胞增殖和蛋白表达。结果与健康对照组相比,REEP5在冠状动脉损伤组及非冠状动脉损伤组中表达显著偏低[(1.05±0.63)比(4.64±1.18)、(3.16±0.85)比(4.64±1.18),P<0.05],且冠状动脉损伤组低于非冠状动脉损伤组(P<0.05)。血小板、红细胞沉降率、白细胞、凝血酶原时间、活化部分凝血活酶时间、纤维蛋白原降解产物、纤维蛋白原与血清REEP5具有显著负相关(P<0.05)。体外细胞实验中:较于对照组,REEP5蛋白和miRNA在模型组中低表达[(1.33±0.15)比(0.34±0.05),(1.24±0.11)比(0.23±0.06),P<0.05],且血管形成数量及血管密度低于对照组(P<0.05)。较于对照组,空白组细胞活力和细胞增殖能力显著降低,LDH活性增加,线粒体膜电位下降,mPTP开放度升高(均P<0.05),细胞早期凋亡增加(P<0.05)。与空白组比较,si-REEP5组细胞活力和细胞增殖能力显著更低,LDH活性增加更显著,线粒体膜电位下降更显著,mPTP开放度显著升高(均P<0.05),细胞早期凋亡显著增加(P<0.05)。与对照组、空白组、si-REEP5组比较,REEP5过表达组细胞活力和细胞增殖能力显著升高,LDH活性显著降低,线粒体膜电位显著升高,mPTP开放度显著下降(均P<0.05),细胞早期凋亡显著降低(P<0.05)。结论在川崎病患儿中,REEP5呈显著低表达,REEP5可通过影响线粒体膜电位和mPTP开放度,影响细胞早期凋亡。

养心2号方对慢性心力衰竭大鼠心肌组织ATP及MMP的影响

目的研究养心2号方对慢性心力衰竭(CHF)大鼠心肌组织能量代谢的影响,探讨其治疗CHF的作用机制。方法将45只清洁级SD大鼠随机分为正常对照组(A组,n=6)及CHF组(n=39),CHF组采用连续28d皮下注射异丙肾上腺素(ISO)方法建立慢性心力衰竭模型。造模成功后,将存活的CHF组大鼠随机分为模型组(B组,n=6)、卡维地洛组(C组,n=6)及养心2号组(D组,n=6)。A组、B组大鼠予蒸馏水灌胃,C组、D组分别予卡维地洛、养心2号方灌胃。各组均连续灌胃28d后,水合氯醛麻醉下取心肌组织,分别测定组织中三磷酸腺苷(ATP)浓度及线粒体膜电位(MMP)水平。结果 1ATP浓度变化:B组ATP浓度下降,与A组比较差异有统计学意义(P<0.05);D组ATP浓度升高,与B组及C组比较,差异有显著统计学意义(P<0.01);2MMP水平变化:B组MMP水平显著下降,与A组比较差异有显著统计学意义(P<0.01);D组、C组MMP水平均明显升高,与B组比较差异有显著统计学意义(P<0.01)。结论养心2号方能升高慢性心衰模型大鼠心肌组织的ATP浓度,同时升高MMP水平,具有明显改善心肌组织能量代谢的作用,该作用可能是养心2号方治疗CHF的作用机制之一。

Gambogic acid induces mitochondria-dependent apoptosis by modulation of Bcl-2 and Bax in mantle cell lymphoma JeKo-1 cells

Objective： To study the mechanisms in gambogic acid （GA） -induced JeKo-1 human Mantle Cell Lymphoma cell apoptosis in vitro. Methods： The proliferation of GA-treated JeKo-1 cells was measured by CCK-8 assay and Ki-67 immunocytochemical detection. Apopt0sis, cell cycle and mitochondrial membrane potential were measured by flow cytometric analysis. Caspase-3, -8 and -9 were detected by colorimetric assay. Bcl-2 and Bax were analyzed by Western blotting. Results： GA inhibited cell growth in a time- and dose- dependent manner. GA induces apoptosis in JeKo- 1 cells but not in normal bone marrow cells, which was involved in reducing the membrane potential of mitochondria, activating caspases-3, -8 and -9 and decreasing the ratio of Bd-2 and Bax without cell cycle arresting. Conclusions： GA induced apoptosis in human MCL JeKo-1 cells by regulating Bcl-2/Bax and activating caspase-3, -8 and -9 via mitochondrial pathway without affecting cell cycle.

Polydatin prevents the induction of secondary brain injury after traumatic brain injury by protecting neuronal mitochondria

Polydatin is thought to protect mitochondria in different cell types in various diseases.Mitochondrial dysfunction is a major contributing factor in secondary brain injury resulting from traumatic brain injury.To investigate the protective effect of polydatin after traumatic brain injury,a rat brain injury model of lateral fluid percussion was established to mimic traumatic brain injury insults.Rat models were intraperitoneally injected with polydatin(30 mg/kg)or the SIRT1 activator SRT1720(20 mg/kg,as a positive control to polydatin).At 6 hours post-traumatic brain injury insults,western blot assay was used to detect the expression of SIRT1,endoplasmic reticulum stress related proteins and p38 phosphorylation in cerebral cortex on the injured side.Flow cytometry was used to analyze neuronal mitochondrial superoxide,mitochondrial membrane potential and mitochondrial permeability transition pore opened.Ultrastructural damage in neuronal mitochondria was measured by transmission electron microscopy.Our results showed that after treatment with polydatin,release of reactive oxygen species in neuronal mitochondria was markedly reduced;swelling of mitochondria was alleviated;mitochondrial membrane potential was maintained;mitochondrial permeability transition pore opened.Also endoplasmic reticulum stress related proteins were inhibited,including the activation of p-PERK,spliced XBP-1 and cleaved ATF6.SIRT1 expression and activity were increased;p38 phosphorylation and cleaved caspase-9/3 activation were inhibited.Neurological scores of treated rats were increased and the mortality was reduced compared with the rats only subjected to traumatic brain injury.These results indicated that polydatin protectrd rats from the consequences of traumatic brain injury and exerted a protective effect on neuronal mitochondria.The mechanisms may be linked to increased SIRT1 expression and activity,which inhibits the p38 phosphorylation-mediated mitochondrial apoptotic pathway.This study was approved by the Animal Care and Use Committee of the Southern Medical University,China(approval number:L2016113)on January 1,2016.

Phosphodiesterase-3 inhibitor （cilostazol） attenuates oxidative stress-induced mitochondrial dysfunction in the heart

Background Cilostazol is a type 3 phosphodiesterase inhibitor which has been previously demonstrated to prevent the occurrence of tachyarrhythmia and improve defibrillation efficacy. However, the mechanism for this beneficial effect is still unclear. Since cardiac mito-chondria have been shown to play a crucial role in fatal cardiac arrhythmias and that oxidative stress is one of the main contributors to arr-hythmia generation, we tested the effects of cilostazol on cardiac mitochondria under severe oxidative stress. Methods Mitochondria were isolated from rat hearts and treated with H2O2 to induce oxidative stress. Cilostazol, at various concentrations, was used to study its protective effects. Pharmacological interventions, including a mitochondrial permeability transition pore （mPTP） blocker, cyclosporine A （CsA）, and an inner membrane anion channel （IMAC） blocker, 4＇-chlorodiazepam （CDP）, were used to investigate the mechanistic role of cilostazol on cardiac mitochondria. Cardiac mitochondrial reactive oxygen species （ROS） production, mitochondrial membrane potential change and mi-tochondrial swelling were determined as indicators of cardiac mitochondrial function. Results Cilostazol preserved cardiac mitochondrial function when exposed to oxidative stress by preventing mitochondrial depolarization, mitochondrial swelling, and decreasing ROS produc-tion. Conclusions Our findings suggest that cardioprotective effects of cilostazol reported previously could be due to its prevention of car-diac mitochondrial dysfunction caused by severe oxidative stress.

Control mechanisms in mitochondrial oxidative phosphorylation

Distribution and activity of mitochondda are key factors in neuronal development, synaptic plasticity and axogenesis. The majority of energy sources, necessary for cellular functions, originate from oxidative phosphorylation located in the inner mitochondrial membrane. The adenosine-5＇- triphosphate production is regulated by many control mechanism-firstly by oxygen, substrate level, adenosine-5＇-diphosphate level, mitochondrial membrane potential, and rate of coupling and proton leak. Recently, these mechanisms have been implemented by ＂second control mechanisms,＂ such as reversible phosphorylation of the tricarboxylic acid cycle enzymes and electron transport chain complexes, aUosteric inhibition of cytochrome c oxidase, thyroid hormones, effects of fatty acids and uncoupling proteins. Impaired function of mitochondria is implicated in many diseases ranging from mitochondrial myopathies to bipolar disorder and schizophrenia. Mitochondrial dysfunctions are usually related to the ability of mitochondria to generate adenosine-5＇-triphosphate in response to energy demands. Large amounts of reactive oxygen species are released by defective mitochondria similarly, decline of antioxidative enzyme activities （e.g. in the elderly） enhances reactive oxygen species production. We reviewed data concerning neuroplasticity, physiology, and control of mitochondrial oxidative phosphorylation and reactive oxygen species production.

3′-Daidzein sulfonate sodium improves mitochondrial functions after cerebral ischemia/reperfusion injury

3′-Daidzein sulfonate sodium is a new synthetic water-soluble compound derived from daidzein（an active ingredient of the kudzu vine root）. It has been shown to have a protective effect on cerebral ischemia/reperfusion injury in rats. We plan to study the mechanism of its protective effect. 3′-Daidzein sulfonate sodium was injected in rats after cerebral ischemia/reperfusion injury. Results showed that 3′-daidzein sulfonate sodium significantly reduced mitochondrial swelling, significantly elevated the mitochondrial membrane potential, increased mitochondrial superoxide dismutase and glutathione peroxidase activities, and decreased mitochondrial malondialdehyde levels. 3′-Daidzein sulfonate sodium improved the structural integrity of the blood-brain barrier and reduced blood-brain barrier permeability. These findings confirmed that 3′-daidzein sulfonate sodium has a protective effect on mitochondrial functions after cerebral ischemia/reperfusion injury, improves brain energy metabolism, and provides protection against blood-brain barrier damage.

Arsenic trioxide induces multiple myeloma cell apoptosis via disruption of mitochondrial transmembrane potentials and activation of caspase-3

OBJECTIVE: To investigate the response of multiple myeloma (MM) cells to arsenic trioxide (As2O3) and their possible mechanisms. METHODS: Two MM-derived cell lines RPMI8226 and U266 cells were used as in vitro models. Cell apoptosis was assessed by morphology, flow cytometry, and DNA gel electrophoresis. Mitochondrial transmembrane potentials (delta psi m) were evaluated by measuring cellular Rhodamine 123 staining intensity. Protein expression was analyzed using Western blot. RESULTS: Zero point one to 0.5 mumol/L As2O3 inhibited cell proliferation and 2.0 mumol/L As2O3 induced cell apoptosis, while 1.0 mumol/L As2O3 inhibited proliferation with a weak degree of apoptosis induction in RPMI8226 and U266 cell lines. As2O3-induced apoptosis was accompanied by mitochondrial transmembrane potentials (delta psi m) collapse and caspase-3 activation in the presence of intact membrane. Glutathione depleter buthionine sulfoximine enhanced, while disulfide bond-reducing agent dithiothreitol partially antagonized As2O3-induced delta psi m collapse and apoptosis in MM cells. All-trans retinoic acid (ATRA) could also induce apoptosis in RPMI8226 cells, but it did not show any cooperative effects with As2O3. CONCLUSION: As2O3 exerts apoptosis-inducing and growth-inhibiting effects on MM cells, and mitochondrium is a pivotal and common target of As2O3 for apoptosis induction.

丁基苯酞对原代培养神经元线粒体功能的保护作用

目的：探讨丁基苯酞（butylphthalide,NBP）对原代培养神经元在低糖低氧损伤下的保护作用及线粒体作用机制。方法：采用Hoechst 33342和PI共染的方法,观察NBP对低糖低氧损伤造成神经细胞坏死和凋亡的影响,并用荧光探针标记以及分光光度法检测NBP对神经细胞线粒体膜电位、线粒体膜流动性及线粒体呼吸链复合酶IV活性的影响。结果：NBP（10-6-10-4mol/L）能显著减少低糖低氧引起的神经细胞坏死和凋亡;机制研究表明它能明显改善由损伤引起的神经细胞线粒体膜电位、线粒体膜流动性及线粒体呼吸链复合酶IV活性的降低。结论：NBP对低糖低氧损伤导致的神经细胞坏死和凋亡具有良好的保护作用,而线粒体保护可能是其作用机制之一。

丁基苯酞对局灶性脑缺血过程中线粒体损伤的保护作用

目的 探讨抗脑缺血新药丁基苯酞 (NBP)对缺血脑线粒体结构和功能的影响 ,以阐明其改善缺血脑损伤的作用机制。方法 用大鼠大脑中动脉阻断 (MCAO)和原代培养神经元的低糖低氧损伤模型 ,测定神经细胞线粒体的膜流动性、膜电位、总ATPase活性和超微结构的影响。结果 大鼠于MCAO后 1h线粒体膜流动性显著降低。经低糖低氧处理后神经细胞线粒体膜电位和总ATPase活性也明显降低。NBPip能逆转缺血期线粒体膜流动性降低 ;dl ,l 和d NBP能使线粒体膜电位和线粒体总ATPase活性恢复至正常水平。电镜结果显示NBP能明显改善脑缺血再灌引起的线粒体肿胀和空泡化。结论 NBP从形态和功能方面对线粒体发挥保护作用 。

丹参酮ⅡA对大鼠缺氧及正常心肌细胞内钙、膜电位和线粒体膜电位的影响

目的:探讨丹参酮ⅡA(Tan)抗心律失常的分子机理。方法:胰蛋白酶法分离培养心肌细胞,用不同荧光染料分别标记细胞,在激光共聚焦显微镜上测定Tan血清对心肌细胞内钙[Ca2+]i、膜电位(MP)和线粒体膜电位(MMP)的变化。结果:缺氧使心肌细胞[Ca2+]i升高,而使MP和MMP降低,Tan血清降低缺氧心肌细胞[Ca2+]i,升高了缺氧引起的MP和MMP降低,使缺氧状态下MP和MMP保持在基线水平。结论:Tan降低了缺氧引起的[Ca2+]i升高,升高了缺氧引起的MP和MMP降低,保护心肌细胞,防治心律失常。

JC-1单标法流式细胞术检测精子线粒体膜电位的研究

目的:探讨应用荧光染料JC-1单色标记法进行流式细胞术检测精子线粒体膜电位(MMP)的可行性及其临床意义。方法:收集63例男性精液标本,分为生育组(n=31)和不育组(n=32)。通过计算机辅助精液分析系统进行精液常规分析。精液标本洗涤处理后用JC-1染色后上流式细胞仪分析,用发橙红色荧光精子百分率(JC-1+%)表示MMP正常精子的比例。结果:生育组精子JC-1+%为(75.89±15.69)%,显著高于不育组[(54.04±22.21)%,P=0.000]。63例标本中,JC-1+%与精子活动率呈显著正相关(r=0.610,P=0.000),与(a+b)级精子百分率呈显著正相关(r=0.614,P=0.000),与d级精子百分率呈显著负相关(r=-0.504,P=0.000)。JC-1+%与已建立的罗丹明/碘化吡啶双染法检测结果(Rh123+/PI-%)呈显著正相关(r=0.938,P=0.000)。结论:应用流式细胞术JC-1单标法检测精子MMP具有可行性,精子JC-1+%可作为男性不育的辅助诊断指标。

锰染毒对老年大鼠心肌细胞线粒体功能的影响

[目的 ]通过观察染锰后老年大鼠心肌细胞线粒体的膜电位 (ΔψM)及酶复合体活性的变化 ,探讨二价锰对心肌的毒作用机制。 [方法 ] 18个月龄大鼠 ,断头处死 ,提取心肌细胞线粒体 ,经 5 0、10 0、2 0 0、40 0 μmol/L剂量染锰后 ,测定大鼠心肌细胞线粒体酶复合体 (Ⅰ +Ⅲ )和Ⅱ的活性变化 ;急性分离大鼠心肌细胞 ,不同剂量染锰后 ,以罗丹明 12 3孵育 ,用激光共聚焦显微镜观察 5min大鼠心肌细胞内荧光强度改变以反映线粒体膜电位的动态变化。 [结果 ]细胞内荧光强度变化 :5min时各染锰组荧光强度与 0min相比呈下降趋势且差异显著 (P <0 0 5 ) ,其中以 5 0、10 0 μmol/L组下降最为明显 ;5min时各染锰组荧光强度与对照组相比均有非常显著的差异 (P <0 0 1) ,2 0 0 μmol/L组与 40 0 μmol/L组荧光强度最低。线粒体酶复合体活性 :染锰后大鼠心肌细胞线粒体酶复合体 (Ⅰ +Ⅲ )、Ⅱ的活性明显受到抑制 ,染锰浓度与酶复合体的活性呈负相关 ,其相关系数分别为 :酶复合体 (Ⅰ +Ⅲ ) ,r =0 64 9,P <0 0 1;酶复合体Ⅱ ,r =0 60 9,P <0 0 1。 [结论 ]锰可对心肌细胞线粒体造成损伤 ,可能是由于其对心肌细胞线粒体呼吸链中各种酶复合体的活性产生抑制 ,引起质子泵功能下降 ,进而引起ΔψM下降 。

红景天甙对缺氧/缺糖损伤的SH-SY5Y细胞线粒体膜电位的影响

目的 :观察红景天甙对SH -SY5Y细胞缺氧 /缺糖损伤时细胞内 [Ca2 + ]i、细胞凋亡率、细胞线粒体膜电位和活性的变化 ,探讨其对神经细胞线粒体膜电位的影响。方法 :应用细胞培养 ,四唑盐比色实验 (MTT )检测细胞线粒体活性 ,流式细胞术检测细胞内 [Ca2 + ]i、细胞凋亡百分率和线粒体膜电位。结果 :SH -SY5Y细胞缺氧 /缺糖损伤 2、4、6、12h后 ,细胞内 [Ca2 + ]i和细胞凋亡百分率明显高于对照组 ,均有显著差异 (P <0 0 1) ;细胞经缺氧 /缺糖处理后 ,线粒体膜电位和活性明显低于对照组 ,2h时分别为 2 9 17% (P <0 0 1) ,38 80 % (P <0 0 1) ,12h时分别为5 6 72 % (P <0 0 1) ,6 3 5 8% (P <0 0 1) ;红景天甙能显著降低细胞内 [Ca2 + ]i,抑制细胞凋亡的发生 ,提高线粒体膜电位和活性 ,与缺氧 /缺糖损伤组相比均有显著差异 (P <0 0 5 ,P <0 0 1)。结论 :红景天甙可抑制缺氧 /缺糖损伤所致的线粒体膜电位和活性的降低 ,从而具有稳定线粒体膜电位的作用 ,抑制细胞凋亡的发生 。

红景天苷减轻叠氮钠诱导线粒体损伤的作用

目的观察红景天苷对呼吸链复合体IV抑制剂叠氮钠(NaN3)诱导的线粒体损伤的保护作用,探讨其在防治神经退行性疾病中可能的作用机制。方法将叠氮钠与人神经母细胞瘤细胞株SHSY5Y共同孵育,MTT法测定细胞存活力,JC1法检测线粒体膜电位变化。刃天青法检测大鼠脑线粒体功能。结果64mmol·L-1叠氮钠与SHSY5Y共同孵育4h后,细胞存活率明显下降,线粒体膜电位下降。预先加入红景天苷能明显提高细胞存活率,维持线粒体膜电位。650μmol·L-1叠氮钠能使大鼠脑线粒体功能下降,预先加入红景天苷能明显改善线粒体功能。结论红景天苷能够减轻叠氮钠(NaN3)诱导的线粒体损伤,能够改善线粒体功能,这可能是其抗老年痴呆的机制之一。

淀粉样肽Aβ导致线粒体功能紊乱的体内和体外研究

为探索阿尔茨海默症(AD)中β淀粉样肽(Aβ)对线粒体功能的影响,比较了稳定表达人野生型淀粉样前体蛋白(APP)的细胞和同时转入人Swedish突变APP及ΔE9突变PS1的双转细胞(swe.Δ9)的线粒体功能.结果发现,swe.Δ9细胞的线粒体膜电位、细胞色素c氧化酶活性、线粒体膜流动性、ATP含量均明显低于APP细胞,而APP细胞又明显低于对照的转入空质粒的细胞.在转基因小鼠上也得到类似结果:同时转入人Swedish突变APP和人PS1 M146V敲入的双转小鼠的细胞色素c氧化酶活性和ATP含量比只转入Swedish突变APP的Tg2576小鼠更低.结果证明了AD模型中线粒体功能损害程度与Aβ产量的正相关关系.

鱼藤酮对神经瘤细胞线粒体膜电位的影响

[目的 ]探讨农药鱼藤酮对神经细胞线粒体的毒性作用机制。 [方法 ]采用 0 5、0 75、1 0 0 μmol/L三种浓度的鱼藤酮对神经瘤细胞 (SH SY5Y)染毒 2 4h ,通过线粒体特异性染料罗丹明 1 2 3进行荧光标记 ,利用激光扫描共聚焦显微镜观察染毒细胞线粒体的膜电位变化 ,并与未染毒的细胞对照组进行比较。 [结果 ]经图象扫描每个细胞得到 1 6个荧光强度变化数值 ,并对其荧光变化值进行分析。表明鱼藤酮可引起线粒体膜电位的改变 ,高、中剂量组荧光强度变化值(1 2 4 84±0 2 4 0 5、1 2 4 86± 0 30 5 7)与低剂量组、溶剂对照组、空白对照组荧光强度变化值 (1 52 3 0± 0 442 0、1 770 1±0 391 9、1 72 5 4±0 2 70 5)差异均存在显著性 (P <0 0 5) ,且随剂量增高 ,有降低趋势。 [结论 ]提示线粒体膜电位的改变是鱼藤酮神经细胞毒性作用的重要环节之一。