Entity

Time filter

Source Type


Jiang H.,Key Laboratory of Molecular Biophysics of Ministry of Education | Feng J.,Huazhong University of Science and Technology | Du Z.,Key Laboratory of Molecular Biophysics of Ministry of Education | Zhen H.,China Steel Corporation | And 6 more authors.
Journal of Nutritional Biochemistry | Year: 2014

Vglycin, a natural 37-residue polypeptide isolated from pea seeds in which six half-cysteine residues are embedded in three pairs of disulfide bonds, is resistant to digestive enzymes and has antidiabetic potential. To investigate the pharmacological activity of Vglycin in vivo and to examine the mechanisms involved, the therapeutic effect of Vglycin in diabetic rats was examined. Diabetes was induced in Wistar rats by high-fat diet and multiple streptozotocin intraperitoneal injections. Diabetic rats were treated daily with Vglycin for 4 weeks. Body weight, food intake, fasting plasma glucose and insulin levels were assayed weekly. Glucose and insulin tolerance tests were conducted on Day 29. Subsequently, levels of p-Akt in the liver and pancreas and cleaved PARP, Pdx-1 and insulin in the pancreas were detected by immunoblotting. The morphology of the pancreas and the insulin expression in the pancreas were analyzed by hematoxylin-eosin staining and immunohistochemistry, respectively. Furthermore, human liver-derived cell lines were used to explore the in vitro effects of Vglycin on insulin sensitivity and glucose uptake. Chronic treatment with Vglycin normalized fasting glucose levels in diabetic rats. The improvement in glucose homeostasis and the increased insulin sensitivity mediated by restored insulin signaling likely contributed to decreased food intake and reduced body weight. Vglycin protected pancreatic cells from damage by streptozotocin. Although insulin synthesis and secretion in impaired β-cell were not significantly elevated, islets morphology was improved in the Vglycin-treated groups. These results suggest that Vglycin could be useful in Type 2 diabetes for restoring impaired insulin signaling, glucose tolerance and pancreatic function. © 2014 Elsevier Inc. Source


Zhang C.-Y.,Huazhong University of Science and Technology | Zhang C.-Y.,Sinopharm Wuhan Pharmaceutical Industry Design Institute | Dong Y.-S.,Huazhong University of Science and Technology | Li Y.-L.,Huazhong University of Science and Technology | And 4 more authors.
Huaxue Gongcheng/Chemical Engineering (China) | Year: 2013

The volumetric oxygen transfer coefficient of plant cells suspension cultures in the bioreactor differs substantially from the values predicted from aqueous solution or sulfite oxidation. Therefore, there is a real need to have a reliable on-line method for measuring volumetric oxygen transfer coefficient during cultures. A new method for determination of the volumetric oxygen transfer coefficient was proposed based on the dissolved oxygen concentration-time during the aeration following nongassing. The volumetric oxygen transfer coefficient of Taxus media cells suspension cultures in a 10 L bioreactor was measured. The influence of the power input per unit volume and the superficial velocity on the volumetric oxygen transfer coefficient was investigated. An experiential correlation among the volumetric oxygen transfer coefficient KLa, the power input per unit volume N3D2, and the superficial velocity vS in the bioreactor were established. The changes of the volumetric oxygen transfer coefficient, the oxygen uptake rate and the specific oxygen consumption rate for suspension cultures of Taxus media cells in a 10 L bioreactor were researched, and the approaches of the determination of the oxygen uptake rate, the specific oxygen consumption rate and the oxygen saturation concentration in the broth were discussed. The result shows that the effect of aeration amount on the volumetric oxygen transfer coefficient is much higher than that of agitation speed; with the increase of cell biomass, the volumetric oxygen transfer coefficient decreases, the oxygen uptake rate increases, and the specific oxygen consumption rate first increases and then decreases. The results are helpful to the operation control, reactor design and amplification of Taxus media cell suspension cultures in the bioreactor. Source


Zhang C.-Y.,Huazhong University of Science and Technology | Zhang C.-Y.,Key Laboratory of Molecular Biophysics of Ministry of Education | Zhang C.-Y.,Sinopharm Wuhan Pharmaceutical Industry Design Institute | Dong Y.-S.,Huazhong University of Science and Technology | And 9 more authors.
Biochemical Engineering Journal | Year: 2013

For a better understanding of the simulation, optimization, and process control in cell cultures, good kinetic models are necessary for large scale plant cell culture. In this paper, the systematic kinetics of taxol production by Taxus media cell suspension cultures in a stirred 15-L bioreactor under substrate-sufficient conditions and the absence of inducer intervention were studied. A kinetic model of cell growth was established by logistic equation, and kinetic unstructured models of substrate consumption, product synthesis and rheological behavior were constituted, which incorporated energy spilling. These models were verified by comparing the simulation results with those obtained experimentally. These results showed that energy spilling was a key factor that must be considered in constructing unstructured kinetic models of Taxus media cell suspension cultures in a stirred bioreactor under substrate-sufficient conditions. Besides, an optimized operation measure of decreasing energy spilling was proposed. An increase of 17.64% in cell biomass and 14.88% in taxol concentration were obtained when the strategy of limiting added carbon several times was experimentally implemented in a 15-L bioreactor. Results demonstrated that these established models should be helpful in the process prediction and operation optimization to guide the production and amplification of Taxus media cell suspension cultures in a bioreactor. © 2012 Elsevier B.V. Source


Fu C.,Huazhong University of Science and Technology | Fu C.,Key Laboratory of Molecular Biophysics of Ministry of Education | Li L.,Huazhong University of Science and Technology | Li L.,Key Laboratory of Molecular Biophysics of Ministry of Education | And 9 more authors.
Plant Cell Reports | Year: 2012

Gradual loss of secondary metabolite production is a common obstacle in the development of a large-scale plant cell production system. In this study, cell morphology, paclitaxel (Taxol ®) biosynthetic ability, and genetic and epigenetic variations in the long-term culture of Taxus media cv Hicksii cells were assessed over a 5-year period to evaluate the mechanisms of the loss of secondary metabolites biosynthesis capacity in Taxus cell. The results revealed that morphological variations, gradual loss of paclitaxel yield and decreased transcriptional level of paclitaxel biosynthesis key genes occurred during long-term subculture. Genetic and epigenetic variations in these cultures were also studied at different times during culture using amplified fragment-length polymorphism (AFLP), methylation-sensitive amplified polymorphism (MSAP), and high-performance liquid chromatography (HPLC) analyses. A total of 32 primer combinations were used in AFLP amplification, and none of the AFLP loci were found to be polymorphic, thus no major genetic rearrangements were detected in any of the tested samples. However, results from both MSAP and HPLC indicated that there was a higher level of DNA methylation in the low-paclitaxel yielding cell line after long-term culture. Based on these results, we proposed that accumulation of paclitaxel in Taxus cell cultures might be regulated by DNA methylation. To our knowledge, this is the first report of increased methylation with the prolongation of culture time in Taxus cell culture. It provides substantial clues for exploring the gradual loss of the taxol biosynthesis capacity of Taxus cell lines during long-term subculture. Key message DNA methylation maybe involved in the regulation of paclitaxel biosynthesis in Taxus cell culture. © 2012 Springer-Verlag. Source


Li X.-L.,Huazhong University of Science and Technology | Yuan J.,Huazhong University of Science and Technology | Dong Y.-S.,Huazhong University of Science and Technology | Fu C.-H.,Huazhong University of Science and Technology | And 6 more authors.
Journal of Chromatographic Science | Year: 2016

An HPLC method for quantifying total DNA methylation in Taxus chinensis cells is described. Optimal conditions for the method were established as follows: DNA was hydrolyzed with DNA degradase at 37°C for 3 h. The mobile phase was a mixture of Solvent A [50 mM potassium dihydrogen phosphate/triethylamine (100:0.2, v/v)] and Solvent B (methanol); the gradient was 10% (v/v) solvent B. The calibration curves for deoxycytidine monophosphate (dCMP) and methylated dCMP were linear within 1.0-160.0 μg mL-1, with correlation coefficients of 0.9996 and 0.9998. The limits of detection for dCMP and 5-mdCMP were 0.482 and 0.301 ng mL-1, respectively, and the limits of quantification were 1.6 and 1.0 ng mL-1, respectively. The method has been validated according to the current International Conference Harmonization guidelines. The method was able to quantify the content of dCMP and methylated dCMP specifically, accurately and precisely. The global DNA methylation level in different Taxus cells was measured using as little as 3 μg of DNA according to the optimized procedure. In addition, degradation of 5-methylcytosine was prevented. © 2015 The Author 2015. Published by Oxford University Press. Source

Discover hidden collaborations