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991.
992.
Rongsong Li 《Biochemical and biophysical research communications》2009,388(2):406-356
Mitochondrial dysfunction is intimately involved in cardiovascular diseases. Mitochondrial membrane potential (ΔΨm) is coupled with oxidative phosphorylation to drive ATP synthesis. In this study, we examined the effect of physiological pulsatile shear stress (PSS) on ΔΨm and the role of Mn-SOD expression on ΔΨm. Confluent human aortic endothelial cells (HAEC) were exposed to PSS, and ΔΨm was monitored using tetramethylrhodamine methyl ester (TMRM+), a mitochondrial membrane potential probe. PSS significantly increased ΔΨm and the change in ΔΨm was a dynamic process. ΔΨm returned to baseline level after PSS for 2 h followed by static state for 4 h. Mitochondrial Mn-SOD expression and activities were also significantly up-regulated in response to PSS. Silencing Mn-SOD attenuated PSS-mediated ΔΨm increase while adding Mn-SOD mimetic, MnTMPyP, increased ΔΨm to the similar extent as induced by PSS. Our findings suggest that PSS-increased mitochondrial ΔΨm, in part, via Mn-SOD up-regulation. 相似文献
993.
Xiang Wang Li Yang Yao Liu Wei Gao Weiyan Peng K.-L. Paul Sung Lanping Amy Sung 《Journal of biomechanics》2009,42(14):2394-2399
The oxidized low-density lipoprotein (Ox-LDL) plays an important role in atherosclerosis, yet it remains unclear if it damages circulating erythrocytes. In this study, erythrocyte deformability and its membrane proteins after Ox-LDL incubations are investigated by micropipette aspiration, thiol radical measurement, and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Results show that Ox-LDL incubation reduces the erythrocyte deformability, decreases free thiol radical contents in erythrocytes, and induces the cross-linking among membrane proteins. SDS-PAGE analysis reveals a high molecular weight (HMW) complex as well as new bands between spectrins and band 3 and reduced ratios between band 3 and other major membrane skeletal proteins. Analyses indicate that Ox-LDL makes erythrocytes harder to deform through a molecular mechanism by which the oxidation of free thiol radicals forms disulfide bonds among membrane skeletal proteins. 相似文献
994.
Membrane fission is the last step of membrane carrier formation. As fusion, it is a very common process in eukaryotic cells, and participates in the integrity and specificity of organelles. Although many proteins have been isolated to participate in the various membrane fission reactions, we are far from understanding how membrane fission is mechanically triggered. Here we aim at reviewing the well-described examples of dynamin and lipid phase separation, and try to extract the essential requirements for fission. Then, we survey the recent knowledge obtained on other fission reactions, analyzing the similarities and differences with previous examples. 相似文献
995.
Insulin and muscle contraction increase fatty acid transport into muscle by inducing the translocation of FAT/CD36. We examined (a) whether these effects are additive, and (b) whether other fatty acid transporters (FABPpm, FATP1, FATP4, and FATP6) are also induced to translocate. Insulin and muscle contraction increased glucose transport and plasmalemmal GLUT4 independently and additively (positive control). Palmitate transport was also stimulated independently and additively by insulin and by muscle contraction. Insulin and muscle contraction increased plasmalemmal FAT/CD36, FABPpm, FATP1, and FATP4, but not FATP6. Only FAT/CD36 and FATP1 were stimulated in an additive manner by insulin and by muscle contraction. 相似文献
996.
Dabros M Dennewald D Currie DJ Lee MH Todd RW Marison IW von Stockar U 《Bioprocess and biosystems engineering》2009,32(2):161-173
This work evaluates three techniques of calibrating capacitance (dielectric) spectrometers used for on-line monitoring of
biomass: modeling of cell properties using the theoretical Cole–Cole equation, linear regression of dual-frequency capacitance
measurements on biomass concentration, and multivariate (PLS) modeling of scanning dielectric spectra. The performance and
robustness of each technique is assessed during a sequence of validation batches in two experimental settings of differing
signal noise. In more noisy conditions, the Cole–Cole model had significantly higher biomass concentration prediction errors
than the linear and multivariate models. The PLS model was the most robust in handling signal noise. In less noisy conditions,
the three models performed similarly. Estimates of the mean cell size were done additionally using the Cole–Cole and PLS models,
the latter technique giving more satisfactory results. 相似文献
997.
Atsushi Intoh Akira Kurisaki Dr. Yuko Yamanaka Hisashi Hirano Hiroyuki Fukuda Hiromu Sugino Makoto Asashima Professor 《Proteomics》2009,9(1):126-137
Embryonic stem cells (ESCs) are established from the inner cell mass of preimplantation embryos, are capable of self‐renewal, and exhibit pluripotency. Given these unique properties, ESCs are expected to have therapeutic potential in regenerative medicine and as a powerful tool for in vitro differentiation studies of stem cells. Various growth factors and extracellular matrix components regulate the pluripotency and differentiation of ESC progenies. Thus, the cell surface receptors that bind these regulatory factors are crucial for the precise regulation of stem cells. To identify membrane proteins that are involved in the regulation of pluripotent stem cells, the membrane proteins of murine ESCs cultured with or without leukemia inhibitory factor (LIF) were purified and analyzed by quantitative proteomics. 2‐D PAGE‐based analysis using fluorescently labeled proteins and shotgun‐based analysis with isotope‐labeled peptides identified 338 proteins, including transmembrane, membrane‐binding, and extracellular proteins, which were expressed specifically in pluripotent or differentiated murine ESCs. Functions of the identified proteins revealed cell adhesion molecules, channels, and receptors, which are expected to play important roles in the maintenance of murine ESC pluripotency. Membrane proteins that are expressed in pluripotent ESCs but not in differentiated cells such as Slc16a1 and Bsg could be useful for the selection of the stem cells in vitro. 相似文献
998.
999.
Jennifer A. Maynard Dr. Nathan C. Lindquist Jamie N. Sutherland Antoine Lesuffleur Arthur E. Warrington Moses Rodriguez Professor Sang-Hyun Oh Dr. 《Biotechnology journal》2009,4(11):1542-1558
Technologies based on surface plasmon resonance (SPR) have allowed rapid, label-free characterization of protein-protein and protein-small molecule interactions. SPR has become the gold standard in industrial and academic settings, in which the interaction between a pair of soluble binding partners is characterized in detail or a library of molecules is screened for binding against a single soluble protein. In spite of these successes, SPR is only beginning to be adapted to the needs of membrane-bound proteins which are difficult to study in situ but represent promising targets for drug and biomarker development. Existing technologies, such as BIAcoreTM, have been adapted for membrane protein analysis by building supported lipid layers or capturing lipid vesicles on existing chips. Newer technologies, still in development, will allow membrane proteins to be presented in native or near-native formats. These include SPR nanopore arrays, in which lipid bilayers containing membrane proteins stably span small pores that are addressable from both sides of the bilayer. Here, we discuss current SPR instrumentation and the potential for SPR nanopore arrays to enable quantitative, high-throughput screening of G protein coupled receptor ligands and applications in basic cellular biology. 相似文献
1000.
Janka Kubálková Vladimíra Tomečková Pál Perjési Juraj Guzy 《Central European Journal of Biology》2009,4(1):90-96
The cytotoxic and protective effects of selected synthetic chalcone analogues have been shown in previous studies. We studied
their cytotoxic effect on the modification of mitochondrial membrane potential and on DNA. The first spectral information
about the methoxy group as well as the dimethylamino substituent in E-2-arylmethylene-1-benzosuberones molecule was obtained
by absorption and emission spectra. The cytotoxic effect of both cyclic chalcone analogues on DNA were detected by alkaline
single-cell gel electrophoresis. Better fluorescent chalcone analogue E-2-(4′-dimethylamino-benzylidene)-1-benzosuberone was
studied further in fresh isolated mitochondria. The decrease of rat liver mitochondria membrane potential (Δψ) was observed
by fluorescence emission spectra. For the collapsing of mitochondrial potentials and as the negative control of mitochondrial
function the CCCP uncoupler was used. The absorption maximum of the methoxy group was found at a shorter wavelength (λ = 335
nm) than that of the dimethylamino group (λ = 406 nm). The excitation spectra were very similar to the absorption spectra
for both molecules but the emission spectra showed a better fluorescence for dimethylamino derivative. After the addition
of E-2-(4′-dimethylamino-benzylidene)-1-benzosuberone to the intact mitochondria the decrease of mitochondrial membrane potential
Δψ was observed by emisssion fluorescence spectra. Both cyclic chalcone analogues induced DNA damage, which was detected by
alkaline comet assay. Mainly the apoptotic cells were detected, but necrotic cells were also present. Similarities in the
percentages of DNA migration from the head were observed in both treatment groups. Both benzosuberones, with dimethylamino-
and methoxy- substituent, were very active biologically, as shown by DNA results of the comet assay. Due to its better fluorescence
properties, only the fluorophore with dimethylamino substituent was selected for further study of the function of rat liver
mitochondria. Decline of mitochondrial function as well as mitochondrial DNA damage were evident between experimental and
control groups. 相似文献