鱼藤酮诱导SH-SY5Y细胞对过氧化氢损伤易感性增高与硫氧还蛋白下调有关(英文)

帕金森病(PD)的发病机制与线粒体呼吸链复合物I(complex I)活性降低以及氧化应激损伤密切相关.使用complex I特异性抑制物鱼藤酮,损伤人神经母细胞瘤SH-SY5Y细胞后,给予H2O2造成氧化应激损伤,以研究细胞抗氧化损伤能力变化的可能机制.结果表明,鱼藤酮处理后,细胞对H2O2所致氧化损伤的易感性增高,且细胞形态及细胞存活率的改变与鱼藤酮浓度呈量效关系.与此同时,细胞内抗氧化蛋白之一,硫氧还蛋白(thioredoxin)水平在细胞损伤时明显下降.以上结果表明,线粒体complex I抑制对细胞氧化应激易感性的影响可能与胞内硫氧还蛋白水平降低有关,提示硫氧还蛋白在诊断神经元损伤和神经保护中有一定的运用前景.

Protective Effects of Aqueous Extract of Eucommia ulmiodes Oliver Leaves on Liver Mitochondria

[Objective] This study aimed to investigate the protective effects of aqueous extract of Eucommia ulmiodes Oliver leaves （AEO） on liver mitochondrial injury induced by free radicals. [Method] MDA content was determined by thiobarbituric acid colorimetric method; mitochondrial swelling degree was determined by spectrophotometry; the superoxide anion radical scavenging ability was determined using reduced coenzyme I-tetrazolium-phenazine methosulfate as the superoxide anion generation system. Mice were hypodermically injected in the back and neck with D- galactose, after 50 d, the effects of AEO on the activities of superoxide dismutase （SOD）, glutathione peroxidase （GSH-Px） and anti-hydroxyl radicals in mouse liver were determined using kits. [Result] AEO can efficiently reduce the liver injury and inhibit mitochondrial swelling induced by Fe2＋-L-Cys, which can also scavenge superoxide anion and improve the activities of antioxidant enzymes. [Conclusion] This study provided scientific basis for the development and application of AEO resources.

Diurnal Changes of Rubisco and RCA Activities and Their Cellular Localization in Rice

The cellular localization of Rubisco and Rubisco activase (RCA) in rice (Oryza sativa subsp. indica cv. Zhenong 952) leaf was investigated with immunogold-labeled electron microscope techniques on the basis of determining the diurnal changes of photosynthetic rate (Pn), Rubisco and RCA activities, and quantifying two enzyme contents in the leaf with immuno-diffusion method in order to understand why RCA activity decreased in the midday when its contents was high. The results showed that Rubisco mainly was located in chloroplast, and RCA were found both in chloroplast and mitochondria. The lowering of Rubisco in chloroplast as well as Rubisco activity at noon could be one of good reasons to explain the photosynthetic midday depression in leaf. The density of RCA in chloroplast reached the maximum at 14:00 and a valley at 11:00. The result much coincided with the activity of RCA in leaf. In mitochondria, the density of RCA changed abruptly in one day with the highest at 13:00 and it can well elucidate why the activities of Rubisco declined at noon when its amount was increasing. Therefore the cellular localization and/or distribution of Rubisco and RCA during a day is more important for Pn, Rubisco and RCA activities.

Cloning,Sequencing and Molecular Phylogenetic Analysis of the Mitochondrial Cytochrome Oxidase Ⅰ Gene of Chilo suppressalis

[Objective] The research aimed at cloning and analyzing mitochondrial cytochrome oxidase I gene（cox 1）of C.suppressalis.[Method] The mitochondrial cox 1 gene of C.suppressalis was cloned with PCR method and sequenced.Then,cox1 sequences of other 21 Lepidopteran species were obtained by blasting the GenBank with cox 1 gene sequence of C.suppressalis.Finally,homology comparison and molecular phylogenitic analysis among the 22 Lepidopteran species were conducted.[Result] The open reading frame of cox 1 gene from C.suppressalis contained 1 531 nucleotides encoding a putative protein of 510 amino acids.The cox1 gene used a start codon CGA,and an incomplete termination codon composed of only T.Based on the amino acid sequences of cox 1,the molecular phylogenetic tree of Lepidoptera was reconstructed using the maximum likelihood（ML）method.The molecular phylogenetic tree was similar to the morphological phylogenetic tree mainly,but also showed some differences.[Conclusion] The result will provide reference for further research on expression and application of cox 1 gene.

Genetic Analysis of Cultured and Wild Populations of Mytilus coruscus Based on Mitochondrial DNA

DNA sequences from the mitochondrial gene cytochrome oxidase subunit I （mtDNA CO I） were used to estimate the genetic variability in two wild populations and two cultured populations of the hard shelled mussel, Mytilus coruscus. Thirty haplotypes were identified in the four populations. The cultured populations exhibited a lower number of haplotypes and genetic diversity than those of the wild populations, suggesting that a small number of effective founding breeders contributed to the genetic variation of the cultured populations. No significant differentiation was observed between the cultured population and local wild population, implying that persistent gene flow occurred in these populations. This genetic survey is intended as a baseline for future genetic monitoring of M. coruseus aquaculture stocks.

The Phylogenetic Relationships among Four Subspecies of the Genus Locusta Based on Sequences of Three Subunit of Cytochrome Oxidase

[Objective] The aim was to explore the phylogenetic relationships among four subspecies of the genus Locusta.[Method] The sequences of three subunits of cytochrome oxidase of Locusta migratoria tibetensis and Locusta migratoria manilensis were amplified and sequenced（COⅠ 1 539 bp,COⅡ 684 bp,CO Ⅲ 792 bp,with the total of 3 015 bp）.The corresponding sequenses of Locusta migratoria migratoria and Locusta migratoria migratorioides were obtained from GenBank and constructed a multiple alignment.Phylogenic trees of four subspecies of L.migratoria were constructed by Neighbor-Joining,Maximum-parsimony and Bayesian,respectively.[Result] The average content of A ＋ T in three subunits of four subspecies was 69.57%;the third site of codon showed the highest A ＋ T content,and the COⅠ had the highest A ＋ T content（87.6%）;The nucleotide substitution mainly occurred at the third site of codon,and the nucleotide replacement rate of CO Ⅱ was the highest.The second site of codon was conservative,so the replacement rate was in the range of 5.9%-15%.The start codon of COⅠ was CCG or ACG.Genetic distances among four subspecies were ranged from 0.001 to 0.076.The relationship between L.m.tibetensis and Locusta migratoria manilensis was the closest,followed by L.m.migratorioides and L.m.migratorioides,while the genetic distance between L.m.tibetensis and L.m.migratorioides was the largest.[Conclusion] The phylogenetic relationships among four subspecies of Locusta migratoria is L.m.tibetensis,L.m.manilensis,L.m.migratoria,L.m.migratorioides.

Identification of Macropterous Individual of Cixiopsis punctatus(Hemiptera:Fulgoroidea:Tropiduchidae) Based on Morphological and Molecular Data

The macropterous individual of Cixiopsis punctatus Matsumura is recognized based on morphological comparison and the mitochondrial COI gene sequences.The pairwise distances among the specimens examined ranged from 0 to 0.0228.Mean distance between macropterous female（Cixiopsis sp.） and 5 brachypterous specimens of Cixiopsis punctatus is 0.0161,which was close enough to consider the macropterous female and brachypterous specimens to be the same species.The external morphology of macropterous female of Cixiopsis punctatus is firstly illustrated and described.

Mechanisms of Inhibitory Effects of Breviscapine on Lipid Peroxidation in Rat Brain Mitochondria

The mechanisms by which breviscapine (Bre) inhibits the lipid preoxidation in rat brain mitochondria were investigated. The mitochondrial lipid peroxidation of rat brain induced by oxygen free radical was measured by thiobarbituric acid spectrophotometry. The chelating activities of Bre for Fe 2+ were tested by differential spectrum. Superoxide anion (O 2)from xanthine xanthine oxidase (Xan XO) system and hydroxyl radical (·OH) from FeSO 4 H 2O 2 system were determined with spectrophotometry. It was found that Bre could effectively inhibit the lipid peroxidation of brain mitochondria induced by free radicals driven from Xan XO and FeSO 4 H 2O 2 system. The IC 50 of Bre were 93 01 μmol·L -1 for Xan XO system and 62 18 μmol·L -1 for FeSO 4 H 2O 2 system. Bre also scavenged O 2 and ·OH produced by Xan XO and FeSO 4 H 2O 2 systems. The IC 50 of Bre were 32 63 μmol·L -1 for O - 2 and 20 22 μmol·L -1 for ·OH. Furthermore, the chelating Fe 2+ activity of Bre was shown. It may be concluded that Bre inhibited lipid peroxidation at different stages of the reaction of oxygen free redial with the mitochondria membrane: (1) the formation of ·OH; (2) the initiation of the lipid peroxidation, by chelating Fe 2+ and scavenging O 2 as well as ·OH. The scavenging oxygen free radicals and chelating iron are the mechanisms of inhibitory effect of Bre on lipid peroxidation.

Antioxidant dietary approach in treatment of fatty liver: New insights and updates

Non-alcoholic fatty liver disease(NAFLD) is a common clinicopathological condition, encompassing a range of conditions caused by lipid deposition within liver cells. To date, no approved drugs are available for the treatment of NAFLD, despite the fact that it represents a serious and growing clinical problem in the Western world. Identification of the molecular mechanisms leading to NAFLD-related fat accumulation, mitochondrial dysfunction and oxidative balance impairment facilitates the development of specific interventions aimed at preventing the progression of hepatic steatosis. In this review, we focus our attention on the role of dysfunctions in mitochondrial bioenergetics in the pathogenesis of fatty liver. Major data from the literature about the mitochondrial targeting of some antioxidant molecules as a potential treatment for hepatic steatosis are described and critically analysed. There is ample evidence of the positive effects of several classes of antioxidants, such as polyphenols(i.e., resveratrol, quercetin, coumestrol, anthocyanins, epigallocatechin gallate and curcumin), carotenoids(i.e., lycopene, astaxanthin and fucoxanthin) and glucosinolates(i.e., glucoraphanin, sulforaphane, sinigrin and allyl-isothiocyanate), on the reversion of fatty liver. Although the mechanism of action is not yet fully elucidated, in some cases an indirect interaction with mitochondrial metabolism is expected. We believe that such knowledge will eventually translate into the development of novel therapeutic approaches for fatty liver.

Modified particle swarm optimization-based antenna tilt angle adjusting scheme for LTE coverage optimization

In order to solve the challenging coverage problem that the long term evolution（ LTE） networks are facing, a coverage optimization scheme by adjusting the antenna tilt angle（ ATA） of evolved Node B（ e NB） is proposed based on the modified particle swarm optimization（ MPSO） algorithm.The number of mobile stations（ MSs） served by e NBs, which is obtained based on the reference signal received power（RSRP） measured from the MS, is used as the metric for coverage optimization, and the coverage problem is optimized by maximizing the number of served MSs. In the MPSO algorithm, a swarm of particles known as the set of ATAs is available; the fitness function is defined as the total number of the served MSs; and the evolution velocity corresponds to the ATAs adjustment scale for each iteration cycle. Simulation results showthat compared with the fixed ATA, the number of served MSs by e NBs is significantly increased by 7. 2%, the quality of the received signal is considerably improved by 20 d Bm, and, particularly, the system throughput is also effectively increased by 55 Mbit / s.

Sequence Comparison of Partial Cytochrome b Genes of Two Coilia species

Sequence variation of partial cytochrome b genes between two Coilia species, C. ectenes and C. mystus, was in- vestigated. Of the 402 nucleotides, twenty-seven (6.72%) are polymorphic and all are synonymous substitutions. At the third positions of genetic condon of cytochrome b gene, the two species show an extreme anti-G bias (<4%) and a pronounced bias towards A and C (>68%). There is no amino acid sequence divergence between the partial cytochrome b genes of the two species, indicating a close genetic relationship between them. The k-2p genetic distance of partial cytochrome b segment of the two species is 0.072, suggesting that the species were separated 3.6 Ma ago, in the middle Pliocene. Our result reveals that the cytochrome b gene is an appropriate marker for studies of population genetic structures and phylogeographic pat- terns of the two species.

Microstructure and Nonlinear Optical Properties of Very Small Size GaAs Nanogranulae Embedded in SiO_2 Matrix by Magnetron Co-Sputtering

Microstructure of GaAs/SiO 2 nanogranular thin films fabricated by radio frequency magnetron co sputtering technique and postannealing are investigated via atomic force microscope,X ray diffraction,and Rutherford backscattering spectroscopy.The results show that GaAs nanocrystals with average diameters from 1 5nm to 3 2nm (depending on the annealing temperature) are uniformly dispersed in the SiO 2 matrices.GaAs and SiO 2 are found in normal stoichiometry in the films.The nonlinear optical refraction and nonlinear optical absorption are studied by Z scan technique using a single Gaussian beam of pulse laser.The third order nonlinear optical refractive index and nonlinear absorption coefficient are enhanced due to the quantum confinement effects and estimated to be 4×10 -12 m 2/W and 2×10 -5 m/W respectively in nonresonant condition,while 2×10 -11 m 2/W and -1×10 -4 m/W respectively in quasi resonant condition.

Redox status of thioredoxin-1 （TRX1） determines the sensitivity of human liver carcinoma cells （HepG2） to arsenic trioxide-induced cell death

lntracellular redox homeostasis plays a critical role in determining tumor cells＇ sensitivity to drug-induced apoptosis. Here we investigated the role of thioredoxin-1 （TRX1）, a key component of redox regulation, in arsenic trioxide （AS2O3）-induced apoptosis. Over-expression of wild-type TRX1 in HepG2 cells led to the inhibition of As2O3-induced cytochrome c （cyto c） release, caspase activation and apoptosis, and down-regulation of TRX1 expression by RNAi sensitized HepG2 cells to As2O3-induced apoptosis. Interestingly, mutation of the active site of TRX1 from Cys^32/35 to Ser^32/35 converted this molecule from an apoptotic protector to an apoptotic promoter. In an effort to understand the mechanisms of this conversion, we used isolated mitochondria from mouse liver and found that recombinant wild-type TRX1 could protect mitochondria from the apoptotic changes. In contrast, the mutant form of TRX1 alone elicited mitochondria-related apoptotic changes, including the mitochondrial permeability transition pore （mPTP） opening, loss of mitochondrial membrane potential, and cyto c release from mitochondria. These apoptotic effects were inhibited by cyclosporine A （CsA）, indicating that mutant TRX1 targeted to mPTP. Alteration of TRX1 from its reduced form to oxidized form in vivo by 2,4-dinitrochlorobenzene （DNCB）, a specific inhibitor ofTRX reductase, also sensitized HepG2 cells to As203-induced apoptosis. These data suggest that TRX1 plays a central role in regulating apoptosis by blocking cyto c release, and inactivation of TRX1 by either mutation or oxidization of the active site cysteines may sensitize tumor cells to As2O3-induced apoptosis.

Role of MGST1 in reactive intermediate-induced injury

Microsomal glutathione transferase (MGST1, EC 2.5.1.18) is a membrane bound glutathione transferase extensively studied for its ability to detoxify reactive intermediates, including metabolic electrophile intermediates and lipophilic hydroperoxides through its glutathione dependent transferase and peroxidase activities. It is expressed in high amounts in the liver, located both in the endoplasmic reticulum and the inner and outer mitochondrial membranes. This enzyme is activated by oxidative stress. Binding of GSH and modification of cysteine 49 (the oxidative stress sensor) has been shown to increase activation and induce conformational changes in the enzyme. These changes have either been shown to enhance the protective effect ascribed to this enzyme or have been shown to contribute to cell death through mitochondrial permeability transition pore formation. The purpose of this review is to elucidate how one enzyme found in two places in the cell subjected to the same conditions of oxidative stress could both help protect against and contribute to reactive oxygen species-induced liver injury.

Nonalcoholic fatty liver disease and mitochondrial dysfunction

Nonalcoholic fatty liver disease (NAFLD) includes hepatic steatosis, nonalcoholic steatohepatitis (NASH), fibrosis, and cirrhosis. NAFLD is the most common liver disorder in the United States and worldwide. Due to the rapid rise of the metabolic syndrome, the prevalence of NAFLD has recently dramatically increased and will continue to increase. NAFLD has also the potential to progress to hepatocellular carcinoma (HCC) or liver failure. NAFLD is strongly linked to caloric overconsumption, physical inactivity, insulin resistance and genetic factors. Although significant progress in understanding the pathogenesis of NAFLD has been achieved in years, the primary metabolic abnormalities leading to lipid accumulation within hepatocytes has remained poorly understood. Mitochondria are critical metabolic organelles serving as "cellular power plants". Accumulating evidence indicate that hepatic mitochondrial dysfunction is crucial to the pathogenesis of NAFLD. This review is focused on the significant role of mitochondria in the development of NAFLD.

Novel interactions of mitochondria and reactive oxygen/nitrogen species in alcohol mediated liver disease

Mitochondrial dysfunction is known to be a contributing factor to a number of diseases including chronic alcohol induced liver injury. While there is a detailed understanding of the metabolic pathways and proteins of the liver mitochondrion, little is known regarding how changes in the mitochondrial proteome may contribute to the development of hepatic pathologies. Emerging evidence indicates that reactive oxygen and nitrogen species disrupt mitochondrial function through post-translational modifications to the mitochondrial proteome. Indeed, various new affinity labeling reagents are available to test the hypothesis that post-translational modification of proteins by reactive species contributes to mitochondrial dysfunction and alcoholic fatty liver disease. Specialized proteomic techniques are also now available, which allow for identification of defects in the assembly of multi-protein complexes in mitochondria and the resolution of the highly hydrophobic proteins of the inner membrane. In this review knowledge gained from the study of changes to the mitochondrial proteome in alcoholic hepatotoxicity will be described and placed into a mechanistic framework to increase understanding of the role of mitochondrial dysfunction in liver disease.

Swarm intelligence optimization and its application in geophysical data inversion

The inversions of complex geophysical data always solve multi-parameter, nonlinear, and multimodal optimization problems. Searching for the optimal inversion solutions is similar to the social behavior observed in swarms such as birds and ants when searching for food. In this article, first the particle swarm optimization algorithm was described in detail, and ant colony algorithm improved. Then the methods were applied to three different kinds of geophysical inversion problems： （1） a linear problem which is sensitive to noise, （2） a synchronous inversion of linear and nonlinear problems, and （3） a nonlinear problem. The results validate their feasibility and efficiency. Compared with the conventional genetic algorithm and simulated annealing, they have the advantages of higher convergence speed and accuracy. Compared with the quasi-Newton method and Levenberg-Marquardt method, they work better with the ability to overcome the locally optimal solutions.

Mitochondria and the aging heart

The average human life span has markedly increased in modem society largely attributed to advances in medical and therapeutic sciences that have successfully reduced important health risks. However, advanced age results in numerous alterations to cellular and subcellular components that can impact the overall health and function of an individual. Not surprisingly, advanced age is a major risk factor for the development of heart disease in which elderly populations observe increased morbidity and mortality. Even healthy individuals that appear to have normal heart function under resting conditions, actually have an increased susceptibility and vulnerability to stress. This is confounded by the impact that stress and disease can have over time to both the heart and vessels. Although, there is a rapidly growing body of literature investigating the effects of aging on the heart and how age-related alterations affect cardiac function, the biology of aging and underlying mechanisms remain unclear. In this review, we summarize effects of aging on the heart and discuss potential theories of cellular aging with special emphasis on mitoehondrial dysfunction.

Nitric oxide: orchestrating hypoxia regulation through mitochondrial respiration and the endoplasmic reticulum stress response

Mitochondria have long been considered to be the powerhouse of the living cell, generating energy in the form of the molecule ATP via the process of oxidative phosphorylation. In the past 20 years, it has been recognised that they also play an important role in the implementation of apoptosis, or programmed cell death. More recently it has become evident that mitochondria also participate in the orchestration of cellular defence responses.At physiological concentrations, the gaseous molecule nitric oxide (NO) inhibits the mitochondrial enzyme cytochrome c oxidase (complex IV) in competition with oxygen. This interaction underlies the mitochondrial actions of NO, which range from the physiologi- cal regulation of cell respiration, through mitochondrial signalling, to the development of “metabolic hypoxia” – a situation in which, although oxygen is available, the cell is unable to utilise it.

Development of a real-time PCR assay(SYBR Green I) for rapid identification and quantification of scyphomedusae Aurelia sp.1 planulae

The complicated life cycle ofAurelia spp., comprising benthic asexually-reproducing polyps and sexually-reproducing medusae, makes it hard for researchers to identify and track them, especially for early stage individuals, such as planulae. To solve this problem, we developed a real-time PCR assay （SYBR Green I） to identify planulae in both cultured and natural seawater samples. Species-specific primers targeting Aurelia sp.1 mitochondrial 16S rDNA （mr 16S rDNA） regions were designed. Using a calibration curve constructed with plasmids containing the Aurelia sp. 1 mt 16S rDNA fragment and a standard curve for planulae, the absolute number of mt 16S rDNA copies per planula was determined and from that the total number ofplanulae per sample was estimated. For the field samples, a 100-fold dilution of the sample DNA combined with a final concentration of 0.2 μg/μL BSA in the PCR reaction mixture was used to remove real- time PCR inhibitors. Samples collected in Jiaozhou Bay from July to September 2012 were subsequently analyzed using this assay. Peak Aurelia sp.1 planula abundance occurred in July 2012 at stations near Hongdao Island and Qingdao offshore; abundances were very low in August and September. The real-time PCR assay （SYBR Green I） developed here negates the need for traditional microscopic identification, which is laborious and time-consuming, and can detect and quantify jellyfish planulae in field plankton samples rapidly and specifically.