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991.
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993.
Marta H. G. Costa Joana Serra Todd C. McDevitt Joaquim M. S. Cabral Cláudia L. da Silva Frederico Castelo Ferreira 《Biotechnology journal》2021,16(5):2000389
Strategies aiming at increasing the survival and paracrine activity of human mesenchymal stromal cells (MSCs) are of utmost importance to achieve the full therapeutic potential of these cells. Herein, we propose both physical and biochemical strategies to enhance the survival, homing, angiogenic, and immunomodulatory properties of MSCs in vitro. To that purpose, we compared the effect of exposing either 2D monolayer or 3D spheroids of MSCs to (i) hypoxia (2% O2) or to (ii) a hypoxic-mimetic small molecule, dimethyloxalylglycine (DMOG), with cells cultured at 21% O2. 3D-cultured MSC spheroids evidenced higher survival upon exposure to oxidative stress and expressed higher levels of factors involved in tissue repair processes, namely tumor necrosis factor-stimulated gene-6, matrix metalloproteinase-2, and vascular endothelial growth factor. MSCs cultured as 3D spheroids and further exposed to hypoxia or hypoxic-mimetic conditions provided by DMOG synergistically favored the expression of the cell surface marker C-X-C chemokine receptor type-4, involved in homing processes to injured tissues, and adhesion to extracellular matrix components as fibronectin. These results highlight the role of ex vivo preconditioning approaches, presenting a novel strategy that combine biochemical stimuli with 3D spheroid organization of MSCs to maximize their tissue regeneration potential. 相似文献
994.
Paixão Magda F. Takahashi Tamara A. Sassaki Guilherme L. Foerster Luís A. 《BioControl》2021,66(6):753-764
BioControl - Successful long-term cryopreservation of lepidopteran eggs for the mass production of parasitoids of the genus Trichogramma Westwood (Hymenoptera: Trichogrammatidae) requires a more... 相似文献
995.
Mendes Ludmila Moura Moreira Souza Guilherme Antônio Ribeiro Santos Hersilia Andrade 《Hydrobiologia》2022,849(2):281-307
Hydrobiologia - This study identifies hydrodynamic alterations in flow downstream of a dam that are related to hydropower plant (HPP) operation and that might attract Neotropical potamodromous fish... 相似文献
996.
Corrêa-Ferreira Marília Locatelli do Rocio Andrade Pires Amanda Barbosa Igor Resendes Echevarria Aurea Pedrassoli Guilherme Henrique Winnischofer Sheila Maria Brochado Noleto Guilhermina Rodrigues Cadena Sílvia Maria Suter Correia 《Molecular and cellular biochemistry》2022,477(8):2033-2045
Molecular and Cellular Biochemistry - The mesoionic compound 4-phenyl-5-(4-nitro-cinnamoyl)-1,3,4-thiadiazolium-2-phenylamine chloride (MI-D) impairs mitochondrial oxidative phosphorylation and has... 相似文献
997.
Plant Ecology - Fluid-feeding herbivores directly affect host plants through sap consumption. Moreover, they establish mutualistic relationships with ants, which might generate additional... 相似文献
998.
Maria de Lourdes Barriviera Carlos Frederico L Fontes Aída Hassón-Voloch Sonia Renaux W Louro 《Nitric oxide》2005,13(1):10-20
Effects of the nitric oxide donors S-nitroso-glutathione (GSNO) and S-nitroso-N-acetylpenicillamine (SNAP) on Na+,K+-ATPase-rich membrane fragments purified from pig kidney outer medulla were studied using intrinsic fluorescence and ESR of spin-labeled membranes. These S-nitrosothiols differently affected the intrinsic fluorescence of Na+,K+-ATPase: GSNO induced a partial quenching, whereas SNAP produced no alteration. Quenching can be due to a direct modification of exposed tryptophan residues or to an indirect effect caused by reactions of nitrogen oxide reactive species with other residues or even with the membrane lipids. Pre-incubation of Na+,K+-ATPase with 0.4mM GSNO resulted in a modest inhibition of ATPase activity (about 24%) measured under optimal conditions. Stearic acid spin-labeled at the 14th carbon atom (14-SASL) was used to investigate membrane fluidity and the protein-lipid interface. SNAP slightly increased the mobility of bulk lipids from Na+,K+-ATPase-rich membranes, but did not change the fraction of bulk to protein-interacting lipids. Conversely, treatment with GSNO extinguished the ESR signals from 14-SASL, indicating generation of free radicals with high affinity for the lipid moiety. Our results demonstrated that membranes influence bioavailability of reactive nitrogen species and bias the activity of different S-nitrosothiols. 相似文献
999.
Frederico Lage-Pinto Jurandi G. Oliveira Maura Da Cunha Cristina M.M. Souza Carlos E. Rezende Ricardo A. Azevedo Angela P. Vitória 《Environmental and Experimental Botany》2008,64(3):307-313
Chlorophyll a fluorescence parameters and transmission electron microscopy (TEM) were used to assess the stress conditions in water hyacinth along the Paraíba do Sul River (PSR), an important River in southeastern Brazil. The data were obtained at the end of the dry season of 2005 and at the end of the wet season of 2006. Changes in F0 and Fm parameters were observed as differentiated responses, depending on the season. Non-photochemical dissipation (qN and NPQ) from plants was greater in the most industrialized region of the PSR in both seasons. However, Fv/Fm for all samples ranged between 0.77 and 0.81, showing that high maximum quantum yield was maintained. Although the Fv/Fm suggests that the plants were exhibiting normal photochemical activities, ultrastructural changes in chloroplasts showed thylakoids disorganization. Plants from the most industrialized region showed non-stacking grana thylakoids disposition. In spite of these alterations, the membrane integrity was maintained, suggesting an adaptation to adjustment to adverse environmental conditions. 相似文献
1000.
Liu Q Kriksunov IA Graeff R Munshi C Lee HC Hao Q 《The Journal of biological chemistry》2006,281(43):32861-32869
The enzymatic cleavage of the nicotinamide-glycosidic bond on nicotinamide adenine dinucleotide (NAD(+)) has been proposed to go through an oxocarbenium ion-like transition state. Because of the instability of the ionic intermediate, there has been no structural report on such a transient reactive species. Human CD38 is an ectoenzyme that can use NAD(+) to synthesize two calcium-mobilizing molecules. By using NAD(+) and a surrogate substrate, NGD(+), we captured and determined crystal structures of the enzyme complexed with an intermediate, a substrate, and a product along the reaction pathway. Our results showed that the intermediate is stabilized by polar interactions with the catalytic residue Glu(226) rather than by a covalent linkage. The polar interactions between Glu(226) and the substrate 2',3'-OH groups are essential for initiating catalysis. Ser(193) was demonstrated to have a regulative role during catalysis and is likely to be involved in intermediate stabilization. In addition, a product inhibition effect by ADP-ribose (through the reorientation of the product) or GDP-ribose (through the formation of a covalently linked GDP-ribose dimer) was observed. These structural data provide insights into the understanding of multiple catalysis and clues for drug design. 相似文献