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101.
Fressinaud Catherine Thomas Olivier Umerska Anita Monika Saulnier Patrick 《Neurochemical research》2020,45(11):2732-2748
Neurochemical Research - Promoting remyelination in multiple sclerosis is important to prevent axon degeneration, given the lack of curative treatment. Although some growth factors improve this... 相似文献
102.
Alice Ward Racca Michael J. Rynkiewicz Nicholas LaFave Anita Ghosh William Lehman Jeffrey R. Moore 《The Journal of biological chemistry》2020,295(50):17128
Dilated cardiomyopathy (DCM) is associated with mutations in cardiomyocyte sarcomeric proteins, including α-tropomyosin. In conjunction with troponin, tropomyosin shifts to regulate actomyosin interactions. Tropomyosin molecules overlap via tropomyosin–tropomyosin head-to-tail associations, forming a continuous strand along the thin filament. These associations are critical for propagation of tropomyosin''s reconfiguration along the thin filament and key for the cooperative switching between heart muscle contraction and relaxation. Here, we tested perturbations in tropomyosin structure, biochemistry, and function caused by the DCM-linked mutation, M8R, which is located at the overlap junction. Localized and nonlocalized structural effects of the mutation were found in tropomyosin that ultimately perturb its thin filament regulatory function. Comparison of mutant and WT α-tropomyosin was carried out using in vitro motility assays, CD, actin co-sedimentation, and molecular dynamics simulations. Regulated thin filament velocity measurements showed that the presence of M8R tropomyosin decreased calcium sensitivity and thin filament cooperativity. The co-sedimentation of actin and tropomyosin showed weakening of actin-mutant tropomyosin binding. The binding of troponin T''s N terminus to the actin-mutant tropomyosin complex was also weakened. CD and molecular dynamics indicate that the M8R mutation disrupts the four-helix bundle at the head-to-tail junction, leading to weaker tropomyosin–tropomyosin binding and weaker tropomyosin–actin binding. Molecular dynamics revealed that altered end-to-end bond formation has effects extending toward the central region of the tropomyosin molecule, which alter the azimuthal position of tropomyosin, likely disrupting the mutant thin filament response to calcium. These results demonstrate that mutation-induced alterations in tropomyosin–thin filament interactions underlie the altered regulatory phenotype and ultimately the pathogenesis of DCM. 相似文献
103.
104.
Christian T?tzke Tatiana Miranda Wilfried Konrad Julien Gout Nikolay Kardjilov Martin Dawson Ingo Manke Anita Roth-Nebelsick 《Annals of botany》2013,111(4):723-730
Background and Aims
Cold neutron radiography was applied to directly observe embolism in conduits of liana stems with the aim to evaluate the suitability of this method for studying embolism formation and repair. Potential advantages of this method are a principally non-invasive imaging approach with low energy dose compared with synchrotron X-ray radiation, a good spatial and temporal resolution, and the possibility to observe the entire volume of stem portions with a length of several centimetres at one time.Methods
Complete and cut stems of Adenia lobata, Aristolochia macrophylla and Parthenocissus tricuspidata were radiographed at the neutron imaging facility CONRAD at the Helmholtz-Zentrum Berlin für Materialien und Energie, with each measurement cycle lasting several hours. Low attenuation gas spaces were separated from the high attenuation (water-containing) plant tissue using image processing.Key results
Severe cuts into the stem were necessary to induce embolism. The formation and temporal course of an embolism event could then be successfully observed in individual conduits. It was found that complete emptying of a vessel with a diameter of 100 µm required a time interval of 4 min. Furthermore, dehydration of the whole stem section could be monitored via decreasing attenuation of the neutrons.Conclusions
The results suggest that cold neutron radiography represents a useful tool for studying water relations in plant stems that has the potential to complement other non-invasive methods. 相似文献105.
106.
Krzysztof Mędrek Piotr Magnowski Bartłomiej Masojć Anita Chudecka-Głaz Bogdan Torbe Janusz Menkiszak Marek Spaczyński Jacek Gronwald Jan Lubiński Bohdan Górski 《Molecular biology reports》2013,40(3):2145-2147
Among many alterations within the TP53 gene the rs1042522 (C72G, p.Pro72Arg) has been associated with numerous cancers , however the results differ between populations for opposite Pro or Arg alleles. Similar thus inconclusive results are observed in ovarian cancer, which may suggest that the rs1042522 does not influence ovarian carcinogensis directly, but might be linked to another pathogenic alteration. WRAP53 which overlaps the TP53 is required to maintain normal levels of p53 upon DNA damage, but also when altered may independently increase the risk of cancer. To evaluate the association between three SNPs located in WRAP53–TP53 region: rs1042522, rs2287497, rs2287498 and ovarian cancer risk in Polish population we genotyped 626 cases and 1,045 healthy controls. Our results provide the evidence for an association between studied SNPs and a risk of invasive ovarian cancer in Poland. We found that CC homozygotes in rs1042522 were more frequent in cancers when compared to controls (OR = 1.46, p = 0.03). Similarly in WRAP53 both TT homozygotes in rs2287497 (OR = 1.95, p = 0.03) and AA homozygotes in rs2287498 (OR = 2.65, p = 0,01) were more frequent among cases than healthy individuals. There is also a suggestive evidence that specific homozygosity of studied SNPs in TP53–WRAP53 region is significantly overrepresented in ovarian cancer patients. In conclusion SNPs in WRAP53 (rs2287497 and rs2287498) have stronger association with an ovarian cancer risk than rs1042522 in TP53. 相似文献
107.
Anita Tragler Lakshmi Srinivasan Olga Shenderova Melvin McClauren Donald W. Brenner 《Molecular simulation》2013,39(1-2):121-130
Abstract A novel simulation interface is being developed as an educational tool to help students better understand fundamentals of materials science. This interface makes use of virtual reality (VR) technology consisting of PC-based graphics and a force-feedback haptic device. Visualization of atomistic processes with simultaneous tactile sensation via the haptic provides a powerful method for understanding complex phenomena that are otherwise difficult to comprehend. Modules are described that allow students to interactively explore interatomic bonding and single-atom diffusion through materials. 相似文献
108.
Priyanka Jadhav Bhushan PetkarYogesh Pore Anita KulkarniKishorkumar Burade 《Carbohydrate polymers》2013
In an attempt to improve the physicochemical properties of cefixime (CEF), its supramolecular inclusion compounds were prepared with β-cyclodextrin (βCD) and hydroxypropyl-β-cyclodextrin (HPβCD) in presence and/or absence of ternary component l-arginine (ARG) using spray drying technique. Initially, the phase solubility studies revealed a stoichiometry of 1:1 molar ratio with an AL-type of phase solubility curve. The stability constants of binary systems were remarkably improved in presence of ARG, indicating positive effect of its addition. The inclusion complexes were characterized by FTIR, XRPD, DSC, SEM, particle size analysis, and dissolution studies. Further, molecular mechanic (MM) calculations were performed to investigate the possible orientations of CEF inside βCD cavity in presence and/or absence of ternary component. In case of physicochemical studies, the ternary systems performed well as a result of comprehensive effect of ternary complexation and particle size reduction achieved by a spray drying technology. 相似文献
109.
110.
Jeanine H. Heiser Anita M. Schuwald Giacomo Sillani Lian Ye Walter E. Müller Kristina Leuner 《Journal of neurochemistry》2013,127(3):303-313
The non‐selective cationic transient receptor canonical 6 (TRPC6) channels are involved in synaptic plasticity changes ranging from dendritic growth, spine morphology changes and increase in excitatory synapses. We previously showed that the TRPC6 activator hyperforin, the active antidepressant component of St. John's wort, induces neuritic outgrowth and spine morphology changes in PC12 cells and hippocampal CA1 neurons. However, the signaling cascade that transmits the hyperforin‐induced transient rise in intracellular calcium into neuritic outgrowth is not yet fully understood. Several signaling pathways are involved in calcium transient‐mediated changes in synaptic plasticity, ranging from calmodulin‐mediated Ras‐induced signaling cascades comprising the mitogen‐activated protein kinase, PI3K signal transduction pathways as well as Ca2+/calmodulin‐dependent protein kinase II (CAMKII) and CAMKIV. We show that several mechanisms are involved in TRPC6‐mediated synaptic plasticity changes in PC12 cells and primary hippocampal neurons. Influx of calcium via TRPC6 channels activates different pathways including Ras/mitogen‐activated protein kinase/extracellular signal‐regulated kinases, phosphatidylinositide 3‐kinase/protein kinase B, and CAMKIV in both cell types, leading to cAMP‐response element binding protein phosphorylation. These findings are interesting not only in terms of the downstream targets of TRPC6 channels but also because of their potential to facilitate further understanding of St. John's wort extract‐mediated antidepressant activity.