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281.
Miriam Strosova Jana Karlovska Corinne M. Spickett Zuzana Orszagova Silvester Ponist Katarina Bauerova 《Free radical research》2013,47(9):852-864
Adjuvant arthritis (AA) is a condition that involves systemic oxidative stress. Unexpectedly, it was found that sarcoplasmic reticulum Ca2 +-ATPase (SERCA) activity was elevated in muscles of rats with AA compared to controls, suggesting possible conformational changes in the enzyme. There was no alteration in the nucleotide binding site but rather in the transmembrane domain according to the tryptophan polar/non-polar fluorescence ratio. Higher relative expression of SERCA, higher content of nitrotyrosine but no increase in phospholipid oxidation in AA SR was found. In vitro treatments of SR with HOCl showed that in AA animals SERCA activity was more susceptible to oxidative stress, but SR phospholipids were more resistant and SERCA could also be activated by phosphatidic acid. It was concluded that increased SERCA activity in AA was due to increased levels of SERCA protein and structural changes to the protein, probably induced by direct and specific oxidation involving reactive nitrogen species. 相似文献
282.
We compared three different anthraquinones, rhein (4,5-dihydroxy-anthraquinone-2-carboxylic acid), danthron (1,8-dihydroxy-anthraquinone) and chrysophanol (1,8-dihydroxy-3-methylanthraquinone), with respect to their toxicity and ability to induce apoptosis in primary cultures of rat hepatocytes. Rhein was the most effective in producing free radicals, and was the only one of the tested anthraquinones that could induce apoptosis. Addition of 50μM rhein to hepatocyte cultures led to depletion of intracellular reduced glutathione (GSH) and ATP and accumulation of lipid peroxidation products. The substances N,N′-diphenyl-p-phenylenediamine (DPPD), dithiothreitol (DTT), nifedipine and desferal all protected the hepatocytes, i.e. prevented viability loss and ATP depletion, and decreased the GSH depletion.Cultures exposed to rhein for 15min and subsequently rinsed and incubated for 16h under normal culture conditions (complete medium) exhibited apoptosis, as shown by DNA fragmentation, nuclear condensation and positive TUNEL reaction. Pretreatment with the antioxidant DPPD and the iron-chelator desferal gave complete protection against apoptosis.No signs of oxidative cell damage were detected when the cultures were exposed to danthron or chrysophanol. All three anthraquinones did, however, cause an immediate increase in the intracellular Ca2+ concentration.We conclude that rhein, which contains one carboxyl group, is a suitable substrate for one-electron-reducing enzymes and an effective redox cycler, which leads to the production of oxygen-derived free radicals that eventually induce apoptotic cell death. 相似文献
283.
Jelena Živković Milka Jadranin Zoran Pržić Nebojša Marković Danijel Sokolović Katarina Šavikin Nebojša Menković 《化学与生物多样性》2021,18(4):e2000858
In this study, we have analyzed the anthocyanin composition of skin extracts of three red grape varieties Prokupac, Evita and Čokot Zemun in order to distinguish these cultivars based on their anthocyanin profile. Also, mechanical analysis of grape bunches and berries was performed. According to our results, seventeen anthocyanins were identified using LC/MS technique and quantitative differences were recorded using HPLC-DAD method. The highest content of total anthocyanins was obtained for Evita variety and the lowest one was recorded in Prokupac. Also, clear differences were observed in anthocyanins ratios. In comparison to Prokupac and Evita varieties, Čokot Zemun was characterized with a high content of coumaroyl derivatives of anthocyanin compounds, while high levels of acetylated derivatives were recorded in Prokupac. Data reported in this study represent a certain contribution to a database of mechanical properties and chemical composition of grape varieties originating from Balkan. 相似文献
284.
Herrera Abreu MT Hughes WE Mele K Lyons RJ Rickwood D Browne BC Bennett HL Vallotton P Brummer T Daly RJ 《Molecular biology of the cell》2011,22(1):105-116
The docking protein Gab2 is overexpressed in several human malignancies, including breast cancer, and is associated with increased metastatic potential. Here we report that Gab2 overexpression in MCF-10A mammary epithelial cells led to delayed cell spreading, a decrease in stress fibers and mature focal adhesions, and enhanced cell migration. Expression of a Gab2 mutant uncoupled from 14-3-3-mediated negative feedback (Gab2(2xA)) led to a more mesenchymal morphology and acquisition of invasive potential. Expression of either Gab2 or Gab2(2xA) led to decreased activation of RhoA, but only the latter increased levels of Rac-GTP. Expression of constitutively active RhoA in MCF-10A/Gab2 cells restored stress fibers and focal adhesions, indicating that Gab2 signals upstream of RhoA to suppress these structures. Mutation of the two Shp2-binding sites to phenylalanine (Gab2(ΔShp2)) markedly reduced the effects of Gab2 on cellular phenotype and RhoA activation. Expression of Gab2 or Gab2(2xA), but not Gab2(ΔShp2), promoted Vav2 phosphorylation and plasma membrane recruitment of p190A RhoGAP. Knockdown of p190A RhoGAP reversed Gab2-mediated effects on stress fibers and focal adhesions. The identification of a novel pathway downstream of Gab2 involving negative regulation of RhoA by p190A RhoGAP sheds new light on the role of Gab2 in cancer progression. 相似文献
285.
Katarina Kindberg Charlotte Oom Neil B. Ingels Matts Karlsson 《Biomechanics and modeling in mechanobiology》2011,10(4):521-528
Left ventricular myofibers are connected by an extensive extracellular collagen matrix to form myolaminar sheets. Histological
cardiac tissue studies have previously observed a pleated transmural distribution of sheets in the ovine heart, alternating
sign of the sheet angle from epicardium to endocardium. The present study investigated temporal variations in myocardial fiber
and sheet architecture during the cardiac cycle. End-diastolic histological measurements made at subepicardium, midwall, and
subendocardium at an anterior-basal and a lateral-equatorial region of the ovine heart, combined with transmural myocardial
Lagrangian strains, showed that the sheet angle but not the fiber angle varied temporally throughout the cardiac cycle. The
magnitude of the sheet angle decreased during systole at all transmural depths at the anterior-basal site and at midwall and
subendocardium depths at the lateral-equatorial site, making the sheets more parallel to the radial axis. These results support
a previously suggested accordion-like wall-thickening mechanism of the myocardial sheets. 相似文献
286.
Microsatellite markers were developed as an identification tool and for analysis of the genetic variation in the pathogens Cronartium flaccidum and Peridermium pini, causing Scots pine blister rust in Pinus spp. Six reference aeciospore samples from Finland were used to examine genetic differences between the two pathogens. Genetic variation within and between 27 lesions on Scots pines from seven locations in Sweden was also investigated. Aeciospores were collected from single aecia within the lesions. Reference samples from P. pini were homozygous for all seven microsatellite loci investigated, while the three C.?flaccidum samples contained heterozygous loci. These results confirm previous studies, where homozygous aeciospores were indicated to be characteristic for P. pini. The majority of aeciospores had two nuclei in both heterozygotic and homozygotic samples. Five of the Swedish lesions contained only homozygotic aecia, while the aecia in the remaining 22 lesions were heterozygotic. All lesions with homozygotic aecia contained only one single multilocus genotype, while many of the lesions with heterozygotic aecia contained several genotypes. The latter indicates the occurrence of multiple matings within a lesion between the resident spermogonia and alien fertilizing spermatia. 相似文献
287.
Ines Cilenšek Amela Hercegovac Jovana Nikolajević Starčević Katarina Vukojević Mirna Saraga Babić Aleksandra Milutinović Živin 《Central European Journal of Biology》2011,6(4):558-564
In diabetic retinopathy (DR) and other angiogenesis-associated diseases, increased levels of cytokines, inflammatory cells,
and angiogenic factors are present. We investigated the hypothesis that rs2243250 polymorphism of the interleukin 4 (IL-4) gene or rs1800896 polymorphism of the interleukin 10 (IL-10) gene, and rs3212227 polymorphism of the 3’ untranslated region (3’ UTR) of the interleukin-12 p40 gene (IL12B) may be associated with the development of proliferative diabetic retinopathy (PDR) in Caucasians with type 2 diabetes (DM2).
This cross sectional case — control study included 189 patients with PDR and 187 patients with type 2 diabetes without PDR.
Polymorphisms rs1800896 of the IL-10 gene, rs2243250 of the IL-4 gene, and rs3212227 of IL12B gene were analyzed by ARMS -PCR and RFLP -PCR methods. Multivariate analysis demonstrated the GG genotype of the rs1800896
polymorphism of the IL-10 gene to be associated with increased risk for PDR (OR=1.99; 95% CI=1.11–3.57; P=0.02), whereas the TT genotype of the rs2243250
polymorphism of the IL-4 gene and the AA genotype of the rs3212227 polymorphism of the IL-12 gene were not independent risk factors for PDR. Our findings suggest that the genetic variations at the IL-10 promoter gene might be a genetic risk factor for PDR in Caucasians with type 2 diabetes. 相似文献
288.
Juuti-Uusitalo K Klunder LJ Sjollema KA Mackovicova K Ohgaki R Hoekstra D Dekker J van Ijzendoorn SC 《PloS one》2011,6(8):e22967
Background
The cytokines TNF (TNFSF2) and IFNγ are important mediators of inflammatory bowel diseases and contribute to enhanced intestinal epithelial permeability by stimulating apoptosis and/or disrupting tight junctions. Apoptosis and tight junctions are also important for epithelial tissue morphogenesis, but the effect of TNF and IFNγ on the process of intestinal epithelial morphogenesis is unknown.Methods/Principal Findings
We have employed a three-dimensional cell culture system, reproducing in vivo-like multicellular organization of intestinal epithelial cells, to study the effect of TNF on intestinal epithelial morphogenesis and permeability. We show that human intestinal epithelial cells in three-dimensional culture assembled into luminal spheres consisting of a single layer of cells with structural, internal, and planar cell polarity. Exposure of preformed luminal spheres to TNF or IFNγ enhanced paracellular permeability, but via distinctive mechanisms. Thus, while both TNF and IFNγ, albeit in a distinguishable manner, induced the displacement of selected tight junction proteins, only TNF increased paracellular permeability via caspase-driven apoptosis and cell shedding. Infliximab and adalumimab inhibited these effects of TNF. Moreover, we demonstrate that TNF via its stimulatory effect on apoptosis fundamentally alters the process of intestinal epithelial morphogenesis, which contributes to the de novo generation of intestinal epithelial monolayers with increased permeability. Also IFNγ contributes to the de novo formation of monolayers with increased permeability, but in a manner that does not involve apoptosis.Conclusions
Our study provides an optimized 3D model system for the integrated analysis of (real-time) intestinal epithelial paracellular permeability and morphogenesis, and reveals apoptosis as a pivotal mechanism underlying the enhanced permeability and altered morphogenesis in response to TNF, but not IFNγ. 相似文献289.
Ivan M��ller Jean T. Coulibaly Thomas F��rst Stefanie Knopp Jan Hattendorf Stefanie J. Krauth Katarina Stete Aur��lie A. Righetti Dominik Glinz Adrien K. Yao Uwe P��hse Eli��zer K. N'Goran J��rg Utzinger 《PLoS neglected tropical diseases》2011,5(7)