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991.
Haishan Tian Lu Tang Yi Wang Xiaojie Wang Lili Guan Jian Zhang Xiaoping Wu Xiaokun Li 《International journal of peptide research and therapeutics》2011,17(2):123-129
Recombinant human keratinocyte growth factor-2 (rhKGF-2) has previously been expressed in Escherichia coli using isopropyl-β-d-thiogalactopyranoside (IPTG), a non-metabolizable and expensive compound, as the inducer. In order to determine whether IPTG
could be replaced with the cheap and natural lactose to induce rhKGF-2 expression, we examined the expression of rhKGF-2 in
flask culture and 30-l fermentation using lactose as the inducer. The optimized fermentation induced with lactose resulted
in 1,382 g of cell mass, corresponding to a 84% enhancement in cell mass compared with IPTG induction. While the expression
level of rhKGF-2 induced with lactose was comparable to that induced with IPTG, the solubility of target protein was increased
by lactose induction than by IPTG induction. The recombinant protein was further purified by cation exchange and heparin-affinity
chromatography. 255 milligrams of pure rhKGF-2 was achieved per liter culture by lactose induction, 52% higher than that obtained
by IPTG induction. A preliminary biochemical characterization of purified rhKGF-2 was performed by Western blotting and mitogenic
activity analysis, and the results demonstrated that the purified lactose-induced rhKGF-2 could react with anti-human KGF-2
antibody and stimulate the proliferation of FGFR2-IIIb-transfected mouse BaF3 cells as IPTG-induced rhKGF-2 could do. 相似文献
992.
Karen F Chambers Joanna F Pearson Davide Pellacani Naveed Aziz Miodrag Gužvić Christoph A Klein Shona H Lang 《Journal of biomedical science》2011,18(1):45
Background
Stromal signalling increases the lateral cell adhesions of prostate epithelial cells grown in 3D culture. The aim of this study was to use microarray analysis to identify significant epithelial signalling pathways and genes in this process. 相似文献993.
Yeo Dae Yoon Eun Sook Lee Jong Pil Park Mee Ree Kim Jun Won Lee Tae Hoon Kim Min Kyun Na Jin Hee Kim 《Biotechnology and Bioprocess Engineering》2011,16(6):1099-1105
Hizikia fusiforme is a commonly used food that possesses potent anti-bacterial, anti-fungal, and anti-inflammatory activities. The immunostimulatory
activities of aqueous extract of Hizikia fusiforme (HFAE) in RAW 264.7 macrophages and whole spleen cells were investigated. HFAE activated RAW 264.7 macrophages to produce
cytokines such as nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) in
a dose-dependent manner. In addition, HFAE induced the mRNA expression of TNF-α, IL-1β, and IL-6 in RAW 264.7 macrophages.
Moreover, HFAE stimulated proliferation of whole spleen cells and reference mitogen. Taken together, the results demonstrate
that HFAE potently activates the immune function by regulating NO, TNF-α, IL-1β, and IL-6 in RAW 264.7 macrophage and promoting
spleen cell proliferation. 相似文献
994.
995.
Cytoglobin, generated using genetic engineering method, is a kind of recombinant human stellate cell activation-associated
protein. We speculate that it could influence the development of hepatic fibrosis like Sellate cell activation-associated
protein which was discovered by Kawada et al. Therefore, we investigated its anti-fibrosis effect on liver both in vivo and
in vitro. During our research, we found that cytoglobin showed obvious effect compared with the control group on Thioacetamide-induced
liver fibrosis in SD rats, including significantly decrease in aspartate aminotransferase, Hyaluronic acid, laminin and collagen
I(Col I) levels in serum and hydroxyproline in livers, which are the important indices reflecting the degree of hepatic fibrosis.
Meanwhile, the viability of rat hepatic stellate cell line T6 (HSC-T6) cells was inhibited by cytoglobin and the apoptosis
induced by cytoglobin in HSC-T6 cells was detected by Annexin V/PI double staining. Activation of the caspase cascade including
caspase-3 for the intrinsic pathways was demonstrated. The results also showed that the expression of Bcl-2 protein decreased
whereas that of Bax protein increased, leading to an increase of the Bax/Bcl-2 ratio. Our results demonstrated that cytoglobin
exhibited anti-fibrosis activity on livers in vivo and in vitro, involving apoptosis induction. 相似文献
996.
997.
Yao YW Shi Y Jia ZF Jiang YH Gu Z Wang J Aljofan M Sun ZG 《Histochemistry and cell biology》2011,136(2):205-215
To investigate the biological significance of ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) involvement in oocyte maturation,
we screened for proteins that bound to UCH-L1 in mouse ovaries, and we found that the prostate tumor overexpressed-1 (PTOV1)
protein was able to bind to UCH-L1. PTOV1 is highly expressed in prostate cancers and considered as a potential marker for
carcinogenesis and the progress of prostate cancer. It was reported that PTOV1 plays an important role in cell cycle regulation,
but its role in mammalian oocyte development and meiosis is still unclear. In this paper, it was found that the expression
levels of PTOV1 in mouse ovaries progressively increased from prepubescence to adulthood. And we found by immunohistochemistry
that PTOV1 spreaded in both the cytoplasm and nuclei of oocytes during prepuberty, but in normal adult mouse oocytes, it concentrated
not only in nuclei but also on the plasma membrane, though in some oocytes with abnormal shapes, PTOV1 did not display the
typical distribution patterns. In granulosa cells, however, it was found to locate in the cytoplasm at all the selected ages.
In postnatal mouse ovaries (28 days), estradiol treatment induced the adult-specific distribution pattern of PTOV1 in oocytes.
In addition, UCH-L1 was shown to be associated with CDK1, which participated in the regulation of cell cycle and oocyte maturation.
Therefore, we propose that the distribution changes of PTOV1 are age-dependent, and significant for mouse oocyte development
and maturation. Moreover, the discovery that PTOV1 is associated with UCH-L1 in mouse oocytes supports the explanations for
that UCH-L1 is involved in oocyte development and maturation, especially under the regulation of estrogen. 相似文献
998.
Mohamed A. Abdel-Naby Mona Y. Osman Ahmed F. Abdel-Fattah 《World journal of microbiology & biotechnology》2011,27(12):2903-2911
The production of extracellular pullulanase by Bacillus licheniformis NRC22 was investigated using different fermentation modes. In batch culture maximal enzyme activity of 18 U/ml was obtained
after 24 h of growth. In continuous fermentation by the free cells, maximal reactor productivity (4.15 KU/l/h) with enzyme
concentration of 14.8 U/ml and specific productivity of 334.9 U/g wet cells/h was attained at a dilution rate of 0.28/h, over
a period of 25 days. B. licheniformis NRC22 cells were immobilized on Ca-alginate. The immobilization conditions with respect to matrix concentration and cell
load was optimized for maximal enzyme production. In repeated batch operation, the activity of the immobilized cells was stable
during the 10 cycles and the activity remained between 9.8 and 7.7 U/ml. Continuous production of pullulanase by the immobilized
cells was investigated in a packed–bed reactor. Maximal reactor productivity (7.0 KU/h) with enzyme concentration of 16.8 U/ml
and specific productivity of 131.64 U/g wet cells/h was attained at dilution rate of 0.42/h. The enzyme activity in the effluent
started to decline gradually to the level of 8.7 U/ml after 25 days of the operation. 相似文献
999.
Liang Zhang Zhongyang Ding Peng Xu Yuhong Wang Zhenghua Gu Zhu Qian Guiyang Shi Kechang Zhang 《Biotechnology and Bioprocess Engineering》2011,16(3):457-461
Tyrosinase is a key enzyme in the biosynthesis of melanin, and the use of inhibitors against tyrosinase can prevent hyperpigmentation
by inhibiting enzymatic oxidation. However, the current use of tyrosine inhibitors is limited by their low activities and
high toxicities. The aim of the present research was to develop novel whitening agents, or tyrosinase-targeted medicine, from
a submerged culture of the fungus Ganoderma lucidum. Methyl lucidenate F was isolated from the ethanol-soluble-acidic components (ESACs) of G. lucidum, with the structure of ESACs elucidated via UV, LC-MS, and 13C-NMR spectral analysis. The tyrosinase inhibitory activity was measured using catechol as a substrate. Methyl lucidenate
F displayed uncompetitive inhibition of the potato tyrosinase activity, for which Lineweaver-Burk plots revealed a maximum
reaction rate (V
max) of 0.4367/min, Michaelis constant (K
m) of 6.765 mM and uncompetitive inhibition constant (K
i) of 19.22 μM. Meanwhile, methyl lucidenate F (tetra cyclic triterpenoid) exhibited high tyrosinase inhibitory activity, with
an IC50 of 32.23 μM. These results suggest that methyl lucidenate F may serve as a potential candidate for skin-whitening agents. 相似文献
1000.
Non-target organism effects tests on Vip3A and their application to the ecological risk assessment for cultivation of MIR162 maize 总被引:1,自引:0,他引:1
Transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt) provide economic, environmental and health benefits by maintaining or increasing crop yields with fewer applications of
insecticide. To sustain these benefits, it is important to delay the evolution of insect resistance to the proteins, and to
ensure that the proteins do not harm non-target organisms, particularly those that may control secondary pests that would
otherwise flourish because of reduced insecticide applications. Vip3A is a Bt vegetative insecticidal protein that is active against lepidopterous pests. It has a different mode of action from other
proteins for control of Lepidoptera in current Bt crops, and when combined with these proteins, it should help to delay the evolution of pest resistance to Bt crops. This paper presents data on the effects of Vip3A on non-target organisms, and an ecological risk assessment of MIR162
maize, which expresses Vip3Aa20. Laboratory studies indicate few adverse effects of Vip3A to non-target organisms: 11 of 12
species tested showed no adverse effects when exposed to high concentrations of Vip3A relative to estimated exposures resulting
from cultivation of MIR162 maize. Daphnia magna exposed to Vip3Aa20 were unaffected in terms of survival or fecundity, but grew slightly more slowly than unexposed controls.
The data indicate that cultivation of MIR162 maize poses negligible risk to non-target organisms, and that crops producing
Vip3A are unlikely to adversely affect biological control organisms such that benefits from reduced insecticide applications
are lost. 相似文献