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141.
Luong Huynh Do Nguyen Nguyen Hoai Nguyen Cuong Thach 《Molecular and cellular biochemistry》2021,476(9):3329-3340
Molecular and Cellular Biochemistry - Ginseng is commonly used as an herbal medicine for improvement of life quality. It is also used as a supplemental medication with anti-cancer drugs to enhance... 相似文献
142.
Huynh QK Wise SJ Koch KA Castonguay LA Reid BG Pagratis EE Koditek D Glascock CB Pitts KR Turner BA Liu X Hung M Han B Pagratis N 《Journal of biomolecular screening》2011,16(7):724-733
Transforming growth factor β (TGF-β) type I receptor (activin receptor-like kinase 5, ALK5) has been identified as a promising target for fibrotic diseases. To find a novel inhibitor of ALK5, the authors performed a high-throughput screen of a library of 420,000 compounds using dephosphorylated ALK5. From primary hits of 1521 compounds, 555 compounds were confirmed. In total, 124 compounds were then selected for follow-up based on their unique structures and other properties. Repeated concentration-response testing and final interference assays of the above compounds resulted in the discovery of a structurally novel ALK5 inhibitor (compound 8) (N-(thiophen 2-ylmethyl)-3-(3,4,5 trimethoxyphenyl)imidazo[1,2β]pyridazin 6-amine) with a low IC(50) value of 0.7 μM. Compound 8 also inhibited the TGF-β-induced nuclear translocation of SMAD with an EC(50) value of 0.8 μM. Kinetic analysis revealed that compound 8 inhibited ALK5 via mixed-type inhibition, suggesting that it may bind to ALK5 differently than other published adenosine triphosphate site inhibitors. 相似文献
143.
Background
Homeostatic erythropoiesis leads to the formation of mature red blood cells under non-stress conditions, and the production of new erythrocytes occurs as the need arises. In response to environmental stimuli, such as bone marrow transplantation, myelosuppression, or anemia, erythroid progenitors proliferate rapidly in a process referred to as stress erythropoiesis. We have previously demonstrated that heme oxygenase-1 (HO-1) deficiency leads to disrupted stress hematopoiesis. Here, we describe the specific effects of HO-1 deficiency on stress erythropoiesis.Methodology/Principal Findings
We used a transplant model to induce stress conditions. In irradiated recipients that received hmox +/− or hmox +/+ bone marrow cells, we evaluated (i) the erythrocyte parameters in the peripheral blood; (ii) the staining intensity of CD71-, Ter119-, and CD49d-specific surface markers during erythroblast differentiation; (iii) the patterns of histological iron staining; and (iv) the number of Mac-1+-cells expressing TNF-α. In the spleens of mice that received hmox +/− cells, we show (i) decreases in the proerythroblast, basophilic, and polychromatophilic erythroblast populations; (ii) increases in the insoluble iron levels and decreases in the soluble iron levels; (iii) increased numbers of Mac-1+-cells expressing TNF-α; and (iv) decreased levels of CD49d expression in the basophilic and polychromatophilic erythroblast populations.Conclusions/Significance
As reflected by effects on secreted and cell surface proteins, HO-1 deletion likely affects stress erythropoiesis through the retention of erythroblasts in the erythroblastic islands of the spleen. Thus, HO-1 may serve as a therapeutic target for controlling erythropoiesis, and the dysregulation of HO-1 may be a predisposing condition for hematologic diseases. 相似文献144.
Vigouroux Y Mariac C De Mita S Pham JL Gérard B Kapran I Sagnard F Deu M Chantereau J Ali A Ndjeunga J Luong V Thuillet AC Saïdou AA Bezançon G 《PloS one》2011,6(5):e19563
Climate changes will have an impact on food production and will require costly adaptive responses. Adapting to a changing environment will be particularly challenging in sub-Saharan Africa where climate change is expected to have a major impact. However, one important phenomenon that is often overlooked and is poorly documented is the ability of agro-systems to rapidly adapt to environmental variations. Such an adaptation could proceed by the adoption of new varieties or by the adaptation of varieties to a changing environment. In this study, we analyzed these two processes in one of the driest agro-ecosystems in Africa, the Sahel. We performed a detailed study in Niger where pearl millet is the main crop and covers 65% of the cultivated area. To assess how the agro-system is responding to recent recurrent drought, we analyzed samples of pearl millet landraces collected in the same villages in 1976 and 2003 throughout the entire cultivated area of Niger. We studied phenological and morphological differences in the 1976 and 2003 collections by comparing them over three cropping seasons in a common garden experiment. We found no major changes in the main cultivated varieties or in their genetic diversity. However, we observed a significant shift in adaptive traits. Compared to the 1976 samples, samples collected in 2003 displayed a shorter lifecycle, and a reduction in plant and spike size. We also found that an early flowering allele at the PHYC locus increased in frequency between 1976 and 2003. The increase exceeded the effect of drift and sampling, suggesting a direct effect of selection for earliness on this gene. We conclude that recurrent drought can lead to selection for earlier flowering in a major Sahelian crop. Surprisingly, these results suggest that diffusion of crop varieties is not the main driver of short term adaptation to climatic variation. 相似文献
145.
Paolo Zanotti-Fregonara Jeih-San Liow Masahiro Fujita Elodie Dusch Sami S. Zoghbi Elise Luong Ronald Boellaard Victor W. Pike Claude Comtat Robert B. Innis 《PloS one》2011,6(2)
Background
The aim of this study was to test seven previously published image-input methods in state-of-the-art high resolution PET brain images. Images were obtained with a High Resolution Research Tomograph plus a resolution-recovery reconstruction algorithm using two different radioligands with different radiometabolite fractions. Three of the methods required arterial blood samples to scale the image-input, and four were blood-free methods.Methods
All seven methods were tested on twelve scans with [11C](R)-rolipram, which has a low radiometabolite fraction, and on nineteen scans with [11C]PBR28 (high radiometabolite fraction). Logan V T values for both blood and image inputs were calculated using the metabolite-corrected input functions. The agreement of image-derived Logan V T values with the reference blood-derived Logan V T values was quantified using a scoring system. Using the image input methods that gave the most accurate results with Logan analysis, we also performed kinetic modelling with a two-tissue compartment model.Results
For both radioligands the highest scores were obtained with two blood-based methods, while the blood-free methods generally performed poorly. All methods gave higher scores with [11C](R)-rolipram, which has a lower metabolite fraction. Compartment modeling gave less reliable results, especially for the estimation of individual rate constants.Conclusion
Our study shows that: 1) Image input methods that are validated for a specific tracer and a specific machine may not perform equally well in a different setting; 2) despite the use of high resolution PET images, blood samples are still necessary to obtain a reliable image input function; 3) the accuracy of image input may also vary between radioligands depending on the magnitude of the radiometabolite fraction: the higher the metabolite fraction of a given tracer (e.g., [11C]PBR28), the more difficult it is to obtain a reliable image-derived input function; and 4) in association with image inputs, graphical analyses should be preferred over compartmental modelling. 相似文献146.
147.
Matthew L. Bendall Khai Luong Kelly M. Wetmore Matthew Blow Jonas Korlach Adam Deutschbauer Rex R. Malmstrom 《Journal of bacteriology》2013,195(21):4966-4974
We performed whole-genome analyses of DNA methylation in Shewanella oneidensis MR-1 to examine its possible role in regulating gene expression and other cellular processes. Single-molecule real-time (SMRT) sequencing revealed extensive methylation of adenine (N6mA) throughout the genome. These methylated bases were located in five sequence motifs, including three novel targets for type I restriction/modification enzymes. The sequence motifs targeted by putative methyltranferases were determined via SMRT sequencing of gene knockout mutants. In addition, we found that S. oneidensis MR-1 cultures grown under various culture conditions displayed different DNA methylation patterns. However, the small number of differentially methylated sites could not be directly linked to the much larger number of differentially expressed genes under these conditions, suggesting that DNA methylation is not a major regulator of gene expression in S. oneidensis MR-1. The enrichment of methylated GATC motifs in the origin of replication indicates that DNA methylation may regulate genome replication in a manner similar to that seen in Escherichia coli. Furthermore, comparative analyses suggest that many Gammaproteobacteria, including all members of the Shewanellaceae family, may also utilize DNA methylation to regulate genome replication. 相似文献
148.
Huynh QK 《Archives of biochemistry and biophysics》2011,(2):173-180
Signaling via pro-growth G protein coupled receptors triggers phosphorylation of HDAC5 on two serine residues (Ser259 and Ser498), resulting in nuclear export of HDAC5 and de-repression of downstream target genes. In the previous paper we reported the important role of PKD isozymes in the regulation of HDAC5 by phosphorylating Ser498 of HDAC5 [Q.K. Huynh, T.A. Mckinsey, Arch. Biochem. Biophys. 450 (2006) 141–148]. In the present paper, we provide evidence that PKCδ can directly phosphorylate Ser259 of HDAC5. The evidence is based on the following facts (a) isolated kinase fraction from human failing heart tissues contained PKCδ that phosphorylated HDAC5 Ser259 peptide and no significant activity was found for the unbound fraction after they were immunoprecipitated with PKCδ specific antibody; (b) specific inhibitors for PKCδ inhibited kinase activity from isolated fraction and recombinant human PKCδ with similar IC50 values; (c) recombinant human PKCδ can directly phosphorylate full length Ser259 HDAC5 protein and HDAC5 Ser259 peptide. The results suggest that in addition to activation of protein kinase D isozymes by phosphorylating Ser744 and Ser748 at their activation sites, PKCδ may also play a role in the regulation of HDAC5 by phosphorylation of Ser259. 相似文献
149.
Many of the cellular responses to Ca++ signaling are modulated by a family of multifunctional Ca++/calmodulin dependent protein kinases (CaMKs): CaMK I, CaMK II and CaMK IV. In order to further understand the role of CaMKs, we investigated the kinetic mechanism of CaMK II isozymes in comparison with those of CaMK I and CaMK IV by analyzing their steady state kinetics using phospholamban as a phosphoacceptor. The results indicated that (a) the CaMK family’s reaction mechanisms were of the sequential type in which all substrates must bind to enzyme before any product is released; (b) CaMK I and CaMK IV exhibited random sequential mechanism where either phospholamban or ATP can bind to the free enzyme; (c) the data of product inhibition for CaMK IIs best fit with an Ordered Bi Bi mechanism in which phospholamban is the first substrate to bind and ADP is the last product to be released; and (d) the constant α (ratio of apparent dissociation constants for binding peptide in the presence and absence of the second ligand) of all isozymes for ATP and peptide was higher than 1 indicating that the binding of phospholamban to CaMK decreased the enzyme’s affinity toward ATP. 相似文献
150.
Reuse of effluent water from a municipal wastewater treatment plant in microalgae cultivation for biofuel production 总被引:2,自引:0,他引:2
This study assessed the usability of effluent water discharged from a secondary municipal wastewater treatment plant for mass cultivation of microalgae for biofuel production. It was observed that bacteria and protozoa in the effluent water exerted a negative impact on the growth of Chlorella sp. 227. To reduce the effect, filtration or UV-radiation were applied on the effluent water as pre-treatment methods. Of all the pretreatment options tested, the filtration (by 0.2 μm) resulted in the highest biomass and lipid productivity. To be comparable with the growth in the autoclaved effluent water, the filtration with a proper pore size filter (less than 0.45 μm) or UV-B radiation of a proper dose (over 1620 mJ cm−2) are proposed. These findings led us to conclude that the utilization can be realized only when bacteria and other microorganisms are greatly reduced or eliminated from the effluent prior to its use. 相似文献