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11.
Kelsa E Gabehart Simon G Royce Diego J Maselli Shelley K Miyasato Elaine C Davis Mimi LK Tang Claude Jourdan Le Saux 《Respiratory research》2013,14(1):110
Background
Airway inflammation and airway remodeling are the key contributors to airway hyperresponsiveness (AHR), a characteristic feature of asthma. Both processes are regulated by Transforming Growth Factor (TGF)-β. Caveolin 1 (Cav1) is a membrane bound protein that binds to a variety of receptor and signaling proteins, including the TGF-β receptors. We hypothesized that caveolin-1 deficiency promotes structural alterations of the airways that develop with age will predispose to an increased response to allergen challenge.Methods
AHR was measured in Cav1-deficient and wild-type (WT) mice 1 to 12 months of age to examine the role of Cav1 in AHR and the relative contribution of inflammation and airway remodeling. AHR was then measured in Cav1-/- and WT mice after an ovalbumin-allergen challenge performed at either 2 months of age, when remodeling in Cav1-/- and WT mice was equivalent, and at 6 months of age, when the Cav1-/- mice had established airway remodeling.Results
Cav1-/- mice developed increased thickness of the subepithelial layer and a correspondingly increased AHR as they aged. In addition, allergen-challenged Cav1-/- mice had an increase in AHR greater than WT mice that was largely independent of inflammation. Cav1-/- mice challenged at 6 months of age have decreased AHR compared to those challenged at 2 months with correspondingly decreased BAL IL-4 and IL-5 levels, inflammatory cell counts and percentage of eosinophils. In addition, in response to OVA challenge, the number of goblet cells and α-SMA positive cells in the airways were reduced with age in response to OVA challenge in contrast to an increased collagen deposition further enhanced in absence of Cav1.Conclusion
A lack of Cav1 contributed to the thickness of the subepithelial layer in mice as they aged resulting in an increase in AHR independent of inflammation, demonstrating the important contribution of airway structural changes to AHR. In addition, age in the Cav1-/- mice is a contributing factor to airway remodeling in the response to allergen challenge. 相似文献12.
Chun-Chong Fu Chia-Hung Su Tien-Chieh Hung Chih-Hung Hsieh Devi Suryani Wen-Teng Wu 《Bioresource technology》2009,100(18):4183-4186
Microalgae Spirulina platensis were attached to the anode of a membrane-free and mediator-free microbial fuel cell (MFC) to produce electricity through the consumption of biochemical compounds inside the microalgae. An increase in open circuit voltage (OCV) was observed with decreasing light intensity and optimal biomass area density. The highest OCV observation for the MFC was 0.39 V in the dark with a biomass area density on the anode surface of 1.2 g cm−2. Additionally, it was observed that the MFC with 0.75 g cm−2 of biomass area density produced 1.64 mW m−2 of electrical power in the dark, which is superior to the 0.132 mW m−2 produced in the light. Which also means the MFC can be applied to generate electrical power under both day and night conditions. 相似文献
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Suryani Lukman Barry J. Grant Alemayehu A. Gorfe Guy H. Grant J. Andrew McCammon 《PLoS computational biology》2010,6(9)
Ras proteins regulate signaling cascades crucial for cell proliferation and differentiation by switching between GTP- and GDP-bound conformations. Distinct Ras isoforms have unique physiological functions with individual isoforms associated with different cancers and developmental diseases. Given the small structural differences among isoforms and mutants, it is currently unclear how these functional differences and aberrant properties arise. Here we investigate whether the subtle differences among isoforms and mutants are associated with detectable dynamical differences. Extensive molecular dynamics simulations reveal that wild-type K-Ras and mutant H-Ras A59G are intrinsically more dynamic than wild-type H-Ras. The crucial switch 1 and switch 2 regions along with loop 3, helix 3, and loop 7 contribute to this enhanced flexibility. Removing the gamma-phosphate of the bound GTP from the structure of A59G led to a spontaneous GTP-to-GDP conformational transition in a 20-ns unbiased simulation. The switch 1 and 2 regions exhibit enhanced flexibility and correlated motion when compared to non-transitioning wild-type H-Ras over a similar timeframe. Correlated motions between loop 3 and helix 5 of wild-type H-Ras are absent in the mutant A59G reflecting the enhanced dynamics of the loop 3 region. Taken together with earlier findings, these results suggest the existence of a lower energetic barrier between GTP and GDP states of the mutant. Molecular dynamics simulations combined with principal component analysis of available Ras crystallographic structures can be used to discriminate ligand- and sequence-based dynamic perturbations with potential functional implications. Furthermore, the identification of specific conformations associated with distinct Ras isoforms and mutants provides useful information for efforts that attempt to selectively interfere with the aberrant functions of these species. 相似文献
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Aberrant Ras activity is a hallmark of diverse cancers and developmental diseases. Unfortunately, conventional efforts to develop effective small molecule Ras inhibitors have met with limited success. We have developed a novel multi-level computational approach to discover potential inhibitors of previously uncharacterized allosteric sites. Our approach couples bioinformatics analysis, advanced molecular simulations, ensemble docking and initial experimental testing of potential inhibitors. Molecular dynamics simulation highlighted conserved allosteric coupling of the nucleotide-binding switch region with distal regions, including loop 7 and helix 5. Bioinformatics methods identified novel transient small molecule binding pockets close to these regions and in the vicinity of the conformationally responsive switch region. Candidate binders for these pockets were selected through ensemble docking of ZINC and NCI compound libraries. Finally, cell-based assays confirmed our hypothesis that the chosen binders can inhibit the downstream signaling activity of Ras. We thus propose that the predicted allosteric sites are viable targets for the development and optimization of new drugs. 相似文献
16.
The maltose transporter of Escherichia coli is a member of the ATP‐binding cassette (ABC) transporter superfamily. The crystal structures of maltose transporter MalK have been determined for distinct conformations in the presence and absence of the ligand ATP, and other interacting proteins. Using the distinct MalK structures, normal mode analysis was performed to understand the dynamics behavior of the system. A network of dynamically important residues was obtained from the normal mode analysis and the analysis of point mutation on the normal modes. Our results suggest that the intradomain rotation occurs earlier than the interdomain rotation during the maltose‐binding protein (MBP)‐driven conformational changes of MalK. We inquire if protein motion and functional‐driven evolutionary conservation are related. The sequence conservation of MalK was analyzed to derive a network of evolutionarily important residues. There are highly significant correlations between protein sequence and protein dynamics in many regions on the maltose transporter MalK, suggesting a link between the protein evolution and dynamics. The significant overlaps between the network of dynamically important residues and the network of evolutionarily important residues form a network of dynamically conserved residues. Proteins 2009. © 2009 Wiley‐Liss, Inc. 相似文献
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Background
The tolerability and efficacy of single dose albendazole (400 mg), diethylcarbamazine citrate (DEC) (6 mg/kg bodyweight) or co-administration of albendazole (400 mg) + DEC (6 mg/kg bodyweight) was studied in 54 asymptomatic Wuchereria bancrofti microfilaraemic volunteers in a double blind hospital-based clinical study. 相似文献18.
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Asis Azriah Shahriar Saleh Ahmed Naher Laila Saallah Suryani Fatihah Hasan Nudin Nur Kumar Vijay Siddiquee Shafiquzzaman 《Molecular biology reports》2021,48(4):3285-3301
Molecular Biology Reports - Trichoderma is a genus of soil-borne fungus with an abundance of reports of its economic importance in the agriculture industry. Thus, the correct identification of... 相似文献