Calcium Signaling Commands Phagosome Maturation Process

Phagosome–lysosome (P–L) fusion is one of the central immune-effector responses of host. It is known that phagosome maturation process is associated with numerous signaling cascades and among these, important role of calcium (Ca²⁺) signaling has been realized recently. Ca²⁺ plays key roles in actin rearrangement, activation of NADPH oxidase and protein kinase C (PKC). Involvement of Ca²⁺ in these cellular processes directs phagosomal maturation process. Some of the intracellular pathogens have acquired the strategies to modulate Ca²⁺ associated pathways to block P–L fusion process. In this review we have described the mechanism of Ca²⁺ signals that influence P–L fusion by controlling ROS, actin and PKC signaling cascades. We have also discussed the strategies implemented by the intracellular pathogens to manipulate Ca²⁺ signaling to consequently subvert P–L fusion. A detail study of factors associated in manipulating Ca²⁺ signaling may provide new insights for the development of therapeutic tools for more effective treatment options against infectious diseases.     

Hyperbaric oxygen modulates antioxidant enzyme activity in rat skeletal muscles

In skeletal muscle the activity of the enzymatic antioxidants superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) is regulated in response to generation of reactive oxygen species (ROS). Increased activity of these enzymes is observed after repeated bouts of aerobic exercise, a potent stimulus for intracellular ROS production. Hyperbaric oxygen (HBO) inhalation also stimulates intracellular ROS production although the effects of HBO on skeletal muscle SOD, GPx and CAT activity have not been studied. We tested the hypothesis that SOD, GPx and CAT activity is modulated in skeletal muscles in response to acute and repeated HBO administration. In adult male rats acute HBO inhalation (60 min at 3 atmospheres absolute) reduced catalase activity by approximately 51% in slow-twitch soleus muscles. Additionally, repeated HBO inhalation (twice daily for 28 days) increased Mn²⁺-superoxide dismutase activity by approximately 241% in fast-twitch extensor digitorum longus muscles. We conclude that both acute and repeated HBO inhalation can alter enzymatic antioxidant activity in skeletal muscles. Electronic Publication     

活性氧调控因子1在人退变椎间盘中的表达及意义

目的　探讨活性氧调控因子1（reactive oxygen species modulator 1,ROMO1）在退变椎间盘髓核中的表达。 方法　采用免疫组化和荧光探针DCFH-DA检测不同退变髓核组织中ROMO1的表达与(reactive oxygen species, ROS)含量,并分析ROMO1表达水平与ROS含量、椎间盘退变程度的相关性。 结果　各组ROMO1的平均光密度值依次为0.192±0.089、0.328±0.048、0.399±0.053、0.468±0.098;各组ROS结果分别为132.961±15.149、191.889±17.880、218.056±12.845、243.501±30.279。随着椎间盘退变程度的加重, ROMO1蛋白表达量与ROS含量逐渐升高,且差异具有显著性(P<0.05)。ROMO1的表达水平与ROS的含量及椎间盘退变程度均呈正相关关系（P＜0.05）。 结论　ROMO1的表达水平与椎间盘的退变程度呈正相关,这可能与其增加髓核组织内ROS含量而加重氧化应激损伤有关。     

天花粉蛋白诱导黑色素瘤凋亡机制的研究

目的：研究天花粉蛋白(TCS)对黑色素瘤B-16细胞的作用,探讨天花粉蛋白抗肿瘤的机制。方法：(1)应用单细胞电泳及Hoechst33258染核形态观察来研究TCS对黑色素瘤B-16细胞损伤作用。(2)应用激光共聚焦扫描显微术结合特异性荧光探针Fluo-3/AM、H2DCF-DA和DAF-FMdiacetate观察在TCS作用下,单个瘤细胞内钙离子（Ca2+）、一氧化氮（NO）和活性氧（ROS）的信号动态变化,并探讨细胞内ROS和NO的增加与钙离子的关系。结果：(1)终浓度50mg/LTCS孵育3h、6h后,单细胞电泳、Hoechst33258染色的核形态观察未发现与对照组有明显区别;孵育12h后单细胞电泳可见DNA损伤的特征性现象-彗星尾巴;Hoechst33258染色的核形态观察发现有明显的核浓缩和边集现象,出现特征性凋亡小体。(2)终浓度50mg/L的TCS可引起细胞内Ca2+、NO和ROS的生成量明显高于对照组（P＜0.01）。细胞内ROS和NO的增加与钙离子的增加密切相关。结论：天花粉蛋白对黑色素瘤B-16细胞DNA具有较强损伤作用,可诱导其发生凋亡;天花粉蛋白诱导凋亡可能与细胞内钙、ROS和NO的增加有关。     

Preventing HIV-1 Tat-induced neuronal apoptosis using antioxidant enzymes: mechanistic and therapeutic implications

HIV-1 proteins, especially gp120 and Tat, elicit reactive oxygen species (ROS) and cause neuron apoptosis. We used antioxidant enzymes, Cu/Zn superoxide dismutase (SOD1) and glutathione peroxidase (GPx1) to study signaling and neuroprotection from Tat-induced apoptosis. SOD1 converts superoxide to peroxide; GPx1 converts peroxide to water. Primary human neurons were transduced with SV40-derived vectors carrying SOD1 and GPx1, then HIV-1 Tat protein was added. Both SV(SOD1) and SV(GPx1) delivered substantial transgene expression. Tat decreased endogenous cellular, but not transduced, SOD1 and GPx1. Tat rapidly increased neuron [Ca(2+)](i), which effect was not altered by SV(SOD1) or SV(GPx1). However, both vectors together blocked Tat-induced [Ca(2+)](i) fluxes. Similarly, neither SV(SOD1) nor SV(GPx1) protected neurons from Tat-induced apoptosis, but both vectors together did. Tat therefore activates multiple signaling pathways, in one of which superoxide acts as an intermediate while the other utilizes peroxide. Gene delivery to protect neurons from Tat must therefore target both.     

G蛋白偶联受体75信号通路在20-羟二十烷四烯酸诱导乳鼠心肌细胞凋亡中的作用

目的:探讨G蛋白偶联受体75(G-protein-coupled receptor 75,GPR75)介导的PLC/PKC信号通路在20-羟二十烷四烯酸(20-hydroxyeicosatetraenoic acid,20-HETE)诱导的乳鼠心肌细胞凋亡中的作用.方法:采用慢病毒转染敲减乳鼠心肌细胞GPR75基因表达...     

Hydrogen peroxide-induced Ca2+ responses in CNS pericytes

A single nucleotide polymorphism (SNP) in the brain-derived neurotrophic factor (BDNF) gene Val66Met has been associated with depression. However, the relationship between this SNP and depression has been mixed, especially when comparing studies of child and adult depression. We examined whether Val66Met would predict depression differentially in mothers versus their daughters. We also examined whether rumination, the tendency to brood and repetitively think about negative information, might serve as a mediator in the path between genotype and depressive symptoms. Participants included 200 individuals (100 mother-daughter pairs) from a high-risk population. The BDNF Val66Met polymorphism was examined in DNA samples from the mothers and daughters, and measures of depressive symptoms and rumination were also obtained. Among the young adolescent girls (ages 10-14), the Val/Val genotype was associated with more depressive symptoms and higher rumination scores compared to the Val/Met genotype. Furthermore, rumination mediated the relationship between genotype and depressive symptoms. However, in the mothers with adult-onset depression the Val/Met genotype was associated with more depressive symptoms, and rumination again mediated the relationship between genotype and depression. Rumination may be an endophenotype in the pathway from the BDNF Val66Met polymorphism to depression. Future work should further explore this mechanism and pursue explanations for its effects at different times in development.     

Beyond ROS clearance: Peroxiredoxins in stress signaling and aging

Antioxidants were long predicted to have lifespan-promoting effects, but in general this prediction has not been well supported. While some antioxidants do seem to have a clear effect on longevity, this may not be primarily as a result of their role in the removal of reactive oxygen species, but rather mediated by other mechanisms such as the modulation of intracellular signaling. In this review we discuss peroxiredoxins, a class of proteinaceous antioxidants with redox signaling and chaperone functions, and their involvement in regulating longevity and stress resistance. Peroxiredoxins have a clear role in the regulation of lifespan and survival of many model organisms, including the mouse, Caenorhabditis elegans and Drosophila melanogaster. Recent research on peroxiredoxins − in these models and beyond − has revealed surprising new insights regarding the interplay between peroxiredoxins and longevity signaling, which will be discussed here in detail. As redox signaling is emerging as a potentially important player in the regulation of longevity and aging, increased knowledge of these fascinating antioxidants and their mode(s) of action is paramount.     

自噬在乙二醇诱导的大鼠肾内晶体形成中的调控作用

目的:探讨自噬在乙二醇诱导的大鼠肾内晶体形成中的调控作用。方法:健康雄性SPF级SD大鼠40只,分为正常对照组、结石模型组、N-乙酰半胱氨酸(NAC)处理组(0.75%乙二醇+NAC)、雷帕霉素处理组(0.75%乙二醇+雷帕霉素)和氯喹处理组(0.75%乙二醇+氯喹),每组8只。干预4周后,应用Western blot和免疫组化检测各组肾脏组织中自噬关键蛋白LC3-II的表达水平;透射电镜观察各组肾组织中自噬泡的数量;应用试剂盒检测各组24 h尿液中总超氧化物歧化酶(T-SOD)和谷胱甘肽过氧化物酶(GSH-Px)的水平;全自动生化仪检测各组血清肌酐及尿素氮的水平;ELISA法检测各组24 h尿液中的中性粒细胞明胶酶相关脂质运载蛋白(NGAL)和肾损伤分子1(Kim-1)的水平。钙盐染色法观测各组肾脏晶体的沉积情况,评价肾组织的病理学变化。结果:与结石模型组相比,雷帕霉素处理组和氯喹处理组中LC3-II的表达水平和自噬泡数量均增加,而在NAC处理组中LC3-II的表达水平和自噬泡数量均减少(P0.05)。与结石组相比,雷帕霉素处理组中T-SOD和GSH-Px水平降低,而氯喹处理组和NAC处理组中T-SOD和GSH-Px的活性增加(P0.05)。与正常组相比,结石组中血清肌酐、尿素氮、NGAL和Kim-1的水平及肾脏内晶体沉积增加(P0.05);在雷帕霉素处理组中肾脏损伤进一步加重,晶体沉积进一步增加,而在氯喹处理组和NAC处理组中肾脏损伤明显减轻,晶体的沉积明显减少。结论:乙二醇激活自噬后可以促进大鼠肾内晶体的形成。应用抗氧化剂和自噬抑制剂不仅可以降低肾脏内的自噬水平,还可以减轻肾脏损伤,减少晶体沉积,降低肾结石的形成率。     

高糖通过提高ROS水平和钙超载诱导小鼠MC3T3-E1成骨细胞凋亡

目的:探讨钙离子(Ca2+)超载在高糖诱导成骨细胞株MC3T3-E1凋亡中的作用以及活性氧簇(reactiveoxygenspecies,ROS)的影响。方法:培养小鼠颅骨源性成骨细胞株MC3T3-E1,给予高浓度D-葡萄糖诱导细胞凋亡。采用MTT法检测不同浓度D-葡萄糖处理24和48h后MC3T3-E1细胞的增殖情况;D-葡萄糖(35mmol/L)处理24h后,AnnexinV-FITC/PI检测细胞凋亡;Fura-2/AM荧光探针检测细胞内Ca2+浓度;DCFH-DA荧光探针检测ROS的生成。结果:MC3T3-E1高糖处理后,细胞增殖明显抑制呈剂量效应关系,早期凋亡率和总死亡率分别增加至(24.16±3.53)%和(63.74±4.32)%。高糖处理后细胞内ROS水平明显增加,抗氧化剂N-乙酰半胱氨酸可以在降低ROS水平的同时抑制高糖所引起的成骨细胞凋亡。细胞内游离Ca2+水平也明显增加,并且通过膜通透性Ca2+螯合剂BAPTA-AM处理后,细胞内Ca2+浓度明显降低,同时成骨细胞凋亡率也明显降低。加入镧离子(La3+)离子抑制储量操纵性钙通道(store-operatedCa2+channels,SOCC)可以降低细胞内Ca2+浓度,减低高糖所引起的成骨细胞凋亡。在高糖诱导成骨细胞凋亡中,细胞内ROS和Ca2+的增加呈相互促进的关系。结论:高糖可以通过增加细胞内ROS水平,引起钙离子通过SOCC通道释放,造成细胞内Ca2+超载,从而诱导成骨细胞凋亡。     

西红花酸对H_2O_2诱导PC12细胞损伤的保护作用

目的通过H2O2诱导PC12细胞损伤,建立氧化应激损伤的体外模型,以探讨西红花酸对细胞损伤的保护作用及其相关机制。方法观察不同浓度(0、50、100、200、300、400μmol/L)H2O2损伤PC12细胞12 h,用CCK-8检测细胞活力;不同浓度(0.1、1、5、10μmol/L)西红花酸预处理PC12细胞24 h,观察西红花酸对H2O2(200μmol/L)损伤细胞后的恢复作用,CCK-8检测细胞活力;罗丹明Rh123染色,流式检测线粒体膜电位(MMP);DCF-DA染色荧光照相术检测活性氧(ROS)水平;Western blot检测磷酸化ERK1/2的表达情况。结果 H2O2(0～400μmol/L)作用PC12细胞12 h后,细胞活力分别为(100±4.1)%、(102±1.9)%、(89±11.2)%、(52±2.6)%、(42±1.6)%、(8±0.4)%,细胞损伤呈明显的浓度依耐性;西红花酸预处理后,细胞活力由(45.12±3.15)%,分别上升为(51.88±4.24)%、(65.14±8.19)%、(57.66±5.58)%、(53.61±4.57)%;西红花酸(1μmol/L、5μmol/L)预处理组减少了线粒体膜电位(MMP)的下降,有效清除活性氧(ROS),激活磷酸化ERK1/2。结论上述实验表明西红花酸能对抗H2O2诱导的氧化应激损伤,表明西红花酸有抗氧化作用。     

Mitochondrial energy conversion disturbance with decrease in ATP production as a source of systemic arterial hypertension

Despite numerous efforts, including recent genetic and molecular biology studies, the immediate cause of stationary elevated blood pressure (BP) in any kind of hypertension has not been satisfactorily explained. This review deals with the cellular mechanisms underlying decreased energy status documented in different tissues from experimental rat models of primary and secondary hypertension as well as the involvement of these abnormalities in the pathogenesis of the disease. Such analyses allow us to hypothesize that dysfunction of mitochondrial energy conversion, caused by distinct stimuli, including generalized disturbances of intracellular Ca²⁺ handling and mitochondria calcium overload found in primary hypertension, leads to uncoupling of oxidation and phosphorylation and attenuated ATP synthesis. Examples of arterial hypertension accompanied by mitochondrial uncoupling and cell ATP depletion (hyperthyroidism, cold hypertension, cyclosporine A intake, etc.) may be considered as an additional argument supporting this opinion. It means also that despite of differences in triggering mechanisms of mitochondrial dysfunction in all these models, the final outcome, i.e. decreased mitochondrial ATP production, is similar. Attenuated intracellular ATP content, in turn, results in the long-term maintenance of elevated BP by increased sympathetic outflow, whereas augmented ROS production following mitochondrial dysfunction lowers the capacity of the NO-dependent vascular relaxation. In the light of these data the cause of stationary elevated BP in chronic arterial hypertension should be regarded as a compensatory response to decreased mitochondrial ATP synthesis.     

HSPgp96诱导巨噬细胞呼吸爆发与细胞内外游离钙关系的研究

目的：探讨从小鼠H22肝癌细胞中提纯的热休克蛋白gp96（HSPgp96）对小鼠腹腔巨噬细胞（PEMφ）呼吸爆发的影响及其与细胞内外游离钙的关系。方法：(1)用亲和层析和离子交换层析等方法从小鼠H22肝癌细胞中获得纯化的HSPgp96。(2)用细胞内过氧化物荧光探针H2DCF-DA监测HSPgp96作用于小鼠PEMφ过程中,单个细胞活性氧（ROS）信号的变化,反映PEMφ内呼吸爆发时的变化过程;用荧光探针Fluo-3/AM监测HSPgp96作用于小鼠PEMφ过程中,单个细胞内钙离子（［Ca2+］i）信号的变化。(3)使用细胞膜和细胞内钙通道抑制剂及钙离子载体后,再观察HSPgp96作用后ROS信号的变化。结果：(1)加入HSPgp96后PEMφ内Fluo-3荧光强度立即上升,70s时增幅达161.05%±50.99%;当分别阻断细胞外钙内流、抑制细胞内钙库释放功能后110s增幅分别为84.81%±29.52%和46.21%±17.24%。同时阻断胞内外钙作用,HSPgp96这一诱发功能明显被抑制。加入钙离子载体后可见细胞内荧光强度迅速增强,于110s时达156.98%±45.83%,随后迅速下降。(2)小鼠PEMφ受HSPgp96刺激后表征ROS的荧光强度立即上升,620s达基础荧光值的636.78%±82.02%,随后始终维持在高水平。当分别阻断细胞外钙内流、抑制细胞内钙库释放功能后,再加入HSPgp96后细胞内ROS荧光值上升幅度较小。同时阻断了胞内外钙作用后,HSPgp96刺激后ROS荧光值上升没有明显高峰出现。结论：HSPgp96作用于小鼠PEMφ后,促进了细胞外钙内流并使细胞内钙库释钙,这是HSPgp96诱发细胞内活性氧增加的基本机制。     

TRPMs and neuronal cell death

Death of CNS neurons during acute injury occurs as a result of a complex combination of excitotoxicity, necrosis, apoptosis, oedema and inflammatory reactions. Neuroprotection via glutamate receptor blockade or antioxidant or anti-inflammatory therapy have not proven effective in the clinical treatment of brain damage due to narrow therapeutic windows, poor pharmacokinetics or blockade of the signalling essential for normal excitatory neurotransmission and neuronal survival. Recent work in neuronal biochemistry, genomics and proteomics has increased understanding of the molecular organization of the excitatory synapse and the neuronal postsynaptic density. Transient receptor potential (TRP) channels are an exciting new family of cation channels that are highly expressed in the brain. Several members can be induced by oxidative stress and oxygen free radicals, both of which play important roles in neurodegeneration. Recent work has indicated that members of the melastatin subfamily (TRPM) of TRP proteins, particularly TRPM7 and TRPM2, may play key roles in neuronal death that is activated by oxidative stress and downstream from excitotoxic signal pathways. This discovery provides an exiting new avenue for research into the pathophysiology and treatment of acute neurodegeneration.     

维生素E对大鼠肾结石模型体内活性氧及成石的影响

目的：观测不同剂量维生素E（Vit E）对大鼠肾结石模型体内活性氧（ROS）的影响及Vit E、ROS与肾成石的关系。方法：给Wistar大鼠饮用含1%乙二醇及0.5%氯化铵的自来水产生肾草酸钙结石模型。分为正常组、成石组、不同剂量Vit E治疗组，喂养15 d，取血和右肾组织测定丙二醛（MDA）、过氧化氢酶（CAT）、超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）水平；左肾冰冻切片，偏光显微镜观察结晶情况。结果：成石组体内脂质过氧化产物显著高于正常组，而抗氧化酶显著低于正常组；Vit E治疗组体内脂质过氧化产物显著低于成石组，而抗氧化酶显著高于成石组。肾结晶沉积与Vit E剂量呈负相关。结论：高草酸尿可使机体活性氧产生增多；Vit E可减轻机体的过氧化损伤，降低形成肾结石的危险性；脂质过氧化导致的肾损伤或许是草酸钙结石形成的主要途径。     

枸橼酸铁铵通过提高ROS水平激活MAPK通路并诱导成骨细胞凋亡

目的：探讨铁超载提高人成骨细胞(hFOB1.19)活性氧（ROS）水平在激活丝裂原活化蛋白激酶（MAPK）通路和诱导细胞凋亡中的作用。方法：采用细胞贴壁法培养成骨细胞hFOB1.19,将不同浓度枸橼酸铁铵(100、300、500μmol/L)加入细胞培养基,用MTT法检测成骨细胞增殖活性;DCFH-DA荧光探针检测成骨细胞ROS水平;AnnexinV-FITC/PI法检测细胞凋亡;Westernblotting检测MAPK通路相关蛋白。结果：枸橼酸铁铵处理成骨细胞后,细胞增殖活性明显降低,早期凋亡和总死亡率显著增加;不同浓度的枸橼酸铁铵处理成骨细胞后,其ROS水平分别增高至(35.73±2.52)%、(62.89±4.24)%和(76.06±3.55)%,MAPK通路相关蛋白的表达也明显增加并呈剂量效应关系,抗氧化剂N-乙酰半胱氨酸可以在降低ROS水平及MAPK通路相关蛋白表达的同时抑制枸橼酸铁铵所致的细胞凋亡。结论：枸橼酸铁铵能使成骨细胞增殖受到抑制,并且通过增加细胞内ROS水平,激活MAPK通路,诱导成骨细胞凋亡。     

硫化氢对抗过氧化氢对PC12细胞的损伤作用

目的探讨硫化氢(hydrogen sulfide,H2S)对抗过氧化氢(hydrogen peroxide,H2O2)对PC12细胞的损伤作用及有关机制。方法应用H2O2在PC12细胞建立氧化应激损伤的实验模型;应用甲氮甲唑蓝(MTT)法检测细胞存活率,碘化丙啶(PI)染色流式细胞技术(FCM)检测细胞凋亡率,罗丹明123(Rhodamine 123,Rh123)染色FCM检测细胞线粒体膜电位(mitochondrial membrane potential,MMP),双氢罗丹明123染色FCM检测细胞内活性氧(reactive oxygen species,ROS)的含量。应用硫化氢钠(sodium hydrosulfide,NaHS)作为H2S的供体。结果200μmol和400μmolH2O2作用PC12细胞24h均使细胞的存活率明显降低及凋亡率显著增加,200μmolH2O2引起PC12细胞的MMP明显降低及ROS生成显著增多。当NaHS与H2O2(200或400μmol/L)共同作用于PC12细胞时,NaHS(100～400μmol/L)浓度依赖性的阻断H2O2引起PC12细胞的存活率降低及细胞凋亡率增加。400μmolNaHS明显地阻断200μmolH2O2引起PC12细胞的MMP降低及ROS增多。结论H2S能明显地保护PC12细胞对抗H2O2引起的损伤,阻断MMP降低及ROS生成可能是H2S的细胞保护机制之一。     

参麦注射液对大鼠急性心肌缺血再灌注损伤的影响

摘要目的:观察参麦注射液对大鼠急性心肌缺血再灌注损伤的影响,并探讨其作用机制。方法:结扎冠状动脉左前降支10min再灌15min复制大鼠急性心肌缺血再灌注损伤模型,描记标准肢体Ⅱ导联心电图,测定心肌组织匀浆中超氧化物歧化酶(SOD)、Na⁺,K⁺-ATP酶和Ca²⁺-ATP酶活性及丙二醛(MDA)含量,电镜观察心肌线粒体改变。结果:参麦注射液使再灌注性心律失常的发生率低于模型组、持续时间较短,心肌组织匀浆中SOD、Na⁺,K⁺-ATP酶和Ca²⁺-ATP酶的活性高于模型组,MDA的含量低于模型组,心肌线粒体损伤轻于模型组。结论:参麦注射液对大鼠急性心肌缺血再灌注损伤有明显的防治作用,其机制与减轻氧自由基及钙超载损伤有关。