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11.
Miloslavina Y de Bianchi S Dall'Osto L Bassi R Holzwarth AR 《The Journal of biological chemistry》2011,286(42):36830-36840
The minor light-harvesting complexes CP24, CP26, and CP29 have been proposed to play a key role in the zeaxanthin (Zx)-dependent high light-induced regulation (NPQ) of excitation energy in higher plants. To characterize the detailed roles of these minor complexes in NPQ and to determine their specific quenching effects we have studied the ultrafast fluorescence kinetics in knockout (ko) mutants koCP26, koCP29, and the double mutant koCP24/CP26. The data provide detailed insight into the quenching processes and the reorganization of the Photosystem (PS) II supercomplex under quenching conditions. All genotypes showed two NPQ quenching sites. Quenching site Q1 is formed by a light-induced functional detachment of parts of the PSII supercomplex and a pronounced quenching of the detached antenna parts. The antenna remaining bound to the PSII core was also quenched substantially in all genotypes under NPQ conditions (quenching site Q2) as compared with the dark-adapted state. The latter quenching was about equally strong in koCP26 and the koCP24/CP26 mutants as in the WT. Q2 quenching was substantially reduced, however, in koCP29 mutants suggesting a key role for CP29 in the total NPQ. The observed quenching effects in the knockout mutants are complicated by the fact that other minor antenna complexes do compensate in part for the lack of the CP24 and/or CP29 complexes. Their lack also causes some LHCII dissociation already in the dark. 相似文献
12.
Matthias Oelze Swenja Kr?ller-Sch?n Philipp Welschof Thomas Jansen Michael Hausding Yuliya Mikhed Paul Stamm Michael Mader Elena Zin?ius Saule Agdauletova Anna Gottschlich Sebastian Steven Eberhard Schulz Serge P. Bottari Eric Mayoux Thomas Münzel Andreas Daiber 《PloS one》2014,9(11)
Objective
In diabetes, vascular dysfunction is characterized by impaired endothelial function due to increased oxidative stress. Empagliflozin, as a selective sodium-glucose co-transporter 2 inhibitor (SGLT2i), offers a novel approach for the treatment of type 2 diabetes by enhancing urinary glucose excretion. The aim of the present study was to test whether treatment with empagliflozin improves endothelial dysfunction in type I diabetic rats via reduction of glucotoxicity and associated vascular oxidative stress.Methods
Type I diabetes in Wistar rats was induced by an intravenous injection of streptozotocin (60 mg/kg). One week after injection empagliflozin (10 and 30 mg/kg/d) was administered via drinking water for 7 weeks. Vascular function was assessed by isometric tension recording, oxidative stress parameters by chemiluminescence and fluorescence techniques, protein expression by Western blot, mRNA expression by RT-PCR, and islet function by insulin ELISA in serum and immunohistochemical staining of pancreatic tissue. Advanced glycation end products (AGE) signaling was assessed by dot blot analysis and mRNA expression of the AGE-receptor (RAGE).Results
Treatment with empagliflozin reduced blood glucose levels, normalized endothelial function (aortic rings) and reduced oxidative stress in aortic vessels (dihydroethidium staining) and in blood (phorbol ester/zymosan A-stimulated chemiluminescence) of diabetic rats. Additionally, the pro-inflammatory phenotype and glucotoxicity (AGE/RAGE signaling) in diabetic animals was reversed by SGLT2i therapy.Conclusions
Empagliflozin improves hyperglycemia and prevents the development of endothelial dysfunction, reduces oxidative stress and improves the metabolic situation in type 1 diabetic rats. These preclinical observations illustrate the therapeutic potential of this new class of antidiabetic drugs. 相似文献13.
Ramziya Kiyamova Olga Kostianets Sergey Malyuchik Valeriy Filonenko Vasiliy Usenko Vadym Gurtovyy Yuliya Khozayenko Stepan Antonuk Lloyd Old Ivan Gout 《Molecular biotechnology》2010,46(2):105-112
Medullary breast carcinoma (MBC) is a relatively rare malignancy with heavy lymphocytic infiltration that despite cytologically
anaplastic features and high mitotic index has more favorable prognosis than other types of breast cancer. Lymphocytic infiltration
of tumors reflects ongoing immune response against tumor antigens which could represent a great interest as potential targets
for cancer immunotherapy. The search for MBC antigens by SEREX methodology has not been successful due to a very high titer
of false positive clones, representing immunoglobulin genes. Here, we describe a novel approach for generating cDNA expression
libraries from MBC tumor samples which are depleted of IgG cDNA clones and, therefore, are suitable for the identification
of novel tumor-associated antigens (TAA) by SEREX approach. Modified methodology allowed us to isolate a panel of known and
novel TAA which are currently under further investigation. 相似文献
14.
Acid-sensitive outwardly rectifying anion channels (ASOR) have been described in several mammalian cell types. The present
whole-cell patch-clamp study elucidated whether those channels are expressed in erythrocytes. To this end whole-cell recordings
were made in human erythrocytes from healthy donors treated with low pH and high osmotic pressure. When the pipette solution
had a reduced Cl− concentration, treatment of the cells with Cl−-containing normal and hyperosmotic (addition of sucrose and polyethelene glycol 1000 [PEG-1000] to the Ringer) media with
low pH significantly increased the conductance of the cells at positive voltages. Channel activity was highest in the PEG-1000
media (95 and 300 mM PEG-1000, pH 4.5 and 4.3, respectively) where the current–voltage curves demonstrated strong outward
rectification and reversed at −40 mV. Substitution of the Cl−-containing medium with Cl−-free medium resulted in a decrease of the conductance at hyperpolarizing voltages, a shift in reversal potential (to 0 mV) and loss of outward rectification. The chloride currents were inhibited by chloride channels blockers DIDS and NPPB (IC50 for both was ~1 mM) but not with niflumic acid and amiloride. The observations reveal expression of ASOR in erythrocytes. 相似文献
15.
Salmina Alla B. Komleva Yuliya K. Malinovskaya Nataliya A. Morgun Andrey V. Teplyashina Elena A. Lopatina Olga L. Gorina Yana V. Kharitonova Ekaterina V. Khilazheva Elena D. Shuvaev Anton N. 《Biochemistry. Biokhimii?a》2021,86(6):746-760
Biochemistry (Moscow) - Blood-brain barrier (BBB) is a structural and functional element of the neurovascular unit (NVU), which includes cells of neuronal, glial, and endothelial nature. The main... 相似文献
16.
PrepMS: TOF MS data graphical preprocessing tool 总被引:1,自引:0,他引:1
Karpievitch YV Hill EG Smolka AJ Morris JS Coombes KR Baggerly KA Almeida JS 《Bioinformatics (Oxford, England)》2007,23(2):264-265
We introduce a simple-to-use graphical tool that enables researchers to easily prepare time-of-flight mass spectrometry data for analysis. For ease of use, the graphical executable provides default parameter settings, experimentally determined to work well in most situations. These values, if desired, can be changed by the user. PrepMS is a stand-alone application made freely available (open source), and is under the General Public License (GPL). Its graphical user interface, default parameter settings, and display plots allow PrepMS to be used effectively for data preprocessing, peak detection and visual data quality assessment. AVAILABILITY: Stand-alone executable files and Matlab toolbox are available for download at: http://sourceforge.net/projects/prepms 相似文献
17.
18.
Dimerization of the major birch pollen allergen Bet v 1 is important for its in vivo IgE-cross-linking potential in mice 总被引:1,自引:0,他引:1
Schöll I Kalkura N Shedziankova Y Bergmann A Verdino P Knittelfelder R Kopp T Hantusch B Betzel C Dierks K Scheiner O Boltz-Nitulescu G Keller W Jensen-Jarolim E 《Journal of immunology (Baltimore, Md. : 1950)》2005,175(10):6645-6650
In type I allergy, the cross-linking of membrane IgE on B lymphocytes and of cytophilic IgE on effector cells by their respective allergens are key events. For cross-linking two IgE molecules, allergens need at least two epitopes. On large molecules, these could be different epitopes in a multivalent, or identical epitopes in a symmetrical, fashion. However, the availability of epitopes may be limited on small allergens such as Bet v 1, the major birch pollen allergen. The present work analyzes whether dimerization is required for the cross-linking capacity of this allergen. In immunoblots, murine monoclonal and polyclonal human Bet v 1-specific Abs detected, besides a Bet v 1 monomer of 17 kDa, a dimer of 34 kDa. In dynamic light scattering, Bet v 1 appeared as dimers and even multimers, but a single condition could be defined where it behaved exclusively monomerically. Small-angle x-ray scattering of the monomeric and dimeric samples resulted in diagrams agreeing with the calculated models. Circular dichroism measurements indicated that the structure of Bet v 1 was preserved under monomeric conditions. Skin tests in Bet v 1-allergic mice were positive with Bet v 1 dimer, but remained negative using the monomer. Furthermore, in contrast to dimeric Bet v 1, the monomer was less capable of activating murine memory B cells for IgE production in vivo. Our data indicate that the presentation of two identical epitopes by dimerized allergens is a precondition for cross-linking of IgE on mast cells and B lymphocytes. 相似文献
19.
Yuliya V. Kucherenko Shefalee K. Bhavsar Valentin I. Grischenko Uwe R. Fischer Stephan M. Huber Florian Lang 《The Journal of membrane biology》2010,235(3):177-189
Excessive glucose concentrations foster glycation and thus premature aging of erythrocytes. The present study explored whether
glycation-induced erythrocyte aging is paralleled by features of suicidal erythrocyte death or eryptosis, which is characterized
by cell membrane scrambling with subsequent phosphatidylserine exposure at the cell surface and cell shrinkage. Both are triggered
by increases of cytosolic Ca2+ concentration ([Ca2+]i), which may result from activation of Ca2+ permeable cation channels. Glycation was accomplished by exposure to high glucose concentrations (40 and 100 mM), phosphatidylserine
exposure estimated from annexin binding, cell shrinkage from decrease of forward scatter, and [Ca2+]i from Fluo3-fluorescence in analysis via fluorescence-activated cell sorter. Cation channel activity was determined by means
of whole-cell patch clamp. Glycation of total membrane proteins, immunoprecipitated TRPC3/6/7, and immunoprecipitated L-type
Ca2+ channel proteins was estimated by Western blot testing with polyclonal antibodies used against advanced glycation end products.
A 30–48-h exposure of the cells to 40 or 100 mM glucose in Ringer solution (at 37°C) significantly increased glycation of
membrane proteins, hemoglobin (HbA1c), TRPC3/6/7, and L-type Ca2+ channel proteins, enhanced amiloride-sensitive, voltage-independent cation conductance, [Ca2+]i, and phosphatidylserine exposure, and led to significant cell shrinkage. Ca2+ removal and addition of Ca2+ chelator EGTA prevented the glycation-induced phosphatidylserine exposure and cell shrinkage after glycation. Glycation-induced
erythrocyte aging leads to eryptosis, an effect requiring Ca2+ entry from extracellular space. 相似文献
20.
A new microsporidium, Liebermannia patagonica n. gen., n. sp., is described from midgut and gastric caecum epithelial cells of Tristira magellanica, an apterous grasshopper species of southern Patagonia, Argentina. L.patagonica is diplokaryotic, apansporoblastic, homosporous, and polysporoblastic. Transitional (from merogony to sporogony) stages and sporonts of L. patagonica were surrounded by host rough endoplasmic reticulum. The ovocylindrical spores measured 2.9 +/- 0.09 x 1.2 +/- 0.04 microm (fresh, n = 50), and they had an isofilar polar filament of only three coils and a cluster of tubules instead of a classical posterior vacuole. Prevalence was high (up to 80.6%) at the type locality for the four years sampled . Maximum likelihood , neighbor joining, maximum parismony analyses of the small submit rDNA all placed L.patagonica(Accession No. DQ 239917) in one with Orthosomella operophterae. 相似文献