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991.
Transduced human PEP-1-heat shock protein 27 efficiently protects against brain ischemic insult 总被引:1,自引:0,他引:1
An JJ Lee YP Kim SY Lee SH Lee MJ Jeong MS Kim DW Jang SH Yoo KY Won MH Kang TC Kwon OS Cho SW Lee KS Park J Eum WS Choi SY 《The FEBS journal》2008,275(6):1296-1308
Reactive oxygen species contribute to the development of various human diseases. Ischemia is characterized by both significant oxidative stress and characteristic changes in the antioxidant defense mechanism. Heat shock protein 27 (HSP27) has a potent ability to increase cell survival in response to oxidative stress. In the present study, we have investigated the protective effects of PEP-1-HSP27 against cell death and ischemic insults. When PEP-1-HSP27 fusion protein was added to the culture medium of astrocyte and primary neuronal cells, it rapidly entered the cells and protected them against cell death induced by oxidative stress. Immunohistochemical analysis revealed that, when PEP-1-HSP27 fusion protein was intraperitoneally injected into gerbils, it prevented neuronal cell death in the CA1 region of the hippocampus in response to transient forebrain ischemia. Our results demonstrate that transduced PEP-1-HSP27 protects against cell death in vitro and in vivo, and suggest that transduction of PEP-1-HSP27 fusion protein provides a potential strategy for therapeutic delivery in various human diseases in which reactive oxygen species are implicated, including stroke. 相似文献
992.
993.
A mouse with cataract, Kec, was generated from N-ethyl-N-nitrosourea (ENU) mutagenesis. Cataract in the Kec mouse was observable at about 5 weeks after birth and this gradually progressed to become completely opaque by 12 weeks. Dissection microscopy revealed that vacuoles with a radial or irregular shape were located primarily in the cortex of the posterior and equatorial regions of the lens. At the late stage, the lens structure was distorted, but not ruptured. This cataract phenotype was inherited in an autosomal recessive manner. We performed a genetic linkage analysis using 133 mutant and 67 normal mice produced by mating Kec mutant (BALB/c) and F1 (C57BL/6 x Kec) mice. The Kec locus was mapped to the 3 cM region encompassed by D14Mit34 and D14Mit69. In addition we excluded coding sequences of 9 genes including Rcbtb2, P2ry5, Itm2b, Med4, Nudt15, Esd, Lcp1, Slc25a30, and 2810032E02Rik as the candidate gene that causes cataract in the Kec mouse. 相似文献
994.
Lipase was purified from squid (Todarodes pacificus) liver in an attempt to investigate the possibility of applying the enzyme for biotechnological applications. Crude extract of squid liver was initially fractionated by the batch type ion exchange chromatography. The fraction containing lipase activity was further purified with an octyl-Sepharose column. Finally, lipase was purified by eluting active protein from a non-dissociating polyacrylamide gel after zymographic analysis. Molecular weight of the purified enzyme was determined to be 27 kDa by SDS-polyacrylamide gel electrophoresis. The enzyme showed the highest activity at a temperature range of 35-40 degrees C and at pH 8.0. The activity was almost completely inhibited at 1 mM concentration of Hg(2+) or Cu(2+) ion. Partial amino acid sequence of the enzyme was also determined. 相似文献
995.
The objective of the present study was to identify mitochondrial components associated with the damage caused by iron to the rat heart. Decreased cell viability was assessed by increased presence of lactate dehydrogenase (LDH) in serum. To assess the functional integrity of mitochondria, Reactive Oxygen Species (ROS), the Respiratory Control Ratio (RCR), ATP and chelatable iron content were measured in the heart. Chelatable iron increased 15-fold in the mitochondria and ROS increased by 59%. Deterioration of mitochondrial function in the presence of iron was demonstrated by low RCR (46% decrease) and low ATP content (96% decrease). Using two dimensional gel electrophoresis (2DE), we identified alterations in 21 mitochondrial proteins triggered by iron overload. Significantly, expression of the alpha, beta, and d subunits of F(1)F(o) ATP synthase increased along with the loss of ATP. This suggests that the F(1)F(o) ATP synthase participates in iron metabolism. 相似文献
996.
The altered amino acid (AA) levels as neurotransmitter closely correlate to neurodegenerative conditions including Alzheimer's disease (AD). Target profiling analysis of nineteen AAs in brain cortex samples from three Tg2576 mice as AD model and three littermate mice as control model was achieved as their N(O,S)-ethoxycarbonyl/tert-butyldimethylsilyl derivatives by gas chromatography. Subsequently, star pattern recognition analysis was performed on the brain AA levels of AD mice after normalization to the corresponding control median values. As compared to control mice, gamma-aminobutyric acid among ten AAs found in brain samples was significantly reduced (P 0.01) while leucine was significantly elevated (P 0.02) in AD mice. The normalized AA levels of the three AD mice were transformed into distorted star patterns which was different from the decagonal shape of control median. The present method allowed visual discrimination of the three AD mice from the controls based on the ten normalized AA levels. 相似文献
997.
Hwang JH Kim JY Cha MR Ryoo IJ Choo SJ Cho SM Tsukumo Y Tomida A Shin-Ya K Hwang YI Yoo ID Park HR 《Journal of cellular physiology》2008,215(1):243-250
Glucose deprivation, a pathophysiological cell condition, causes up-regulation of GRP78 and induction of etoposide resistance in human cancer cells. The induction of drug resistance can be partly explained by the fact that GRP78 can block activation of caspase-7 induced by treatment with etoposide. Therefore, downregulating GRP78 expression may be a novel strategy anticancer drug development. Based on that premise, we established a screening program for anticancer agents that exhibit preferential cytotoxic activity for etoposide-resistant cancer cells under glucose-deprived conditions. We recently isolated an active compound, AR-054, from the culture broth of Streptomyces sp., which prevents stress-induced etoposide resistance in vitro. AR-054 was identified as piericidin A, a prototypical compound, by ESI-MS analysis and various NMR spectroscopic methods. Here, we showed that piericidin A suppressed the accumulation of GRP78 protein and was also highly toxic to etoposide-resistant HT-29 cells, with IC50 values for colony formation of 6.4 and 7.7 nM under 2-deoxyglucose supplemented and glucose-deprived conditions, respectively. Interestingly, piericidin A had no effect under normal growth conditions. Therefore, we suggest that piericidin A prevents up-regulation of GRP78, and exhibits cytotoxicity in glucose-deprived HT-29 cells that are resistant to etoposide. 相似文献
998.
High-level expression of an antimicrobial peptide histonin as a natural form by multimerization and furin-mediated cleavage 总被引:2,自引:0,他引:2
Kim JM Jang SA Yu BJ Sung BH Cho JH Kim SC 《Applied microbiology and biotechnology》2008,78(1):123-130
Direct expression of an antimicrobial peptide (AMP) in Escherichia coli causes several problems such as the toxicity of AMP to the host cell, its susceptibility to proteolytic degradation, and
decreased antimicrobial activity due to the additional residue(s) introduced after cleavage of AMPs from fusion partners.
To overcome these problems and produce a large quantity of a potent AMP histonin (RAGLQFPVGKLLKKLLKRLKR) in E. coli, an efficient expression system was developed, in which the toxicity of histonin was neutralized by a fusion partner F4 (a
truncated fragment of PurF protein) and the productivity was increased by a multimeric expression of a histonin gene. The
expression level of the fusion proteins reached a maximum with a 12-mer of a histonin gene. In addition, because of the RLKR
residues present at the C terminus of histonin, furin cleavage of the multimeric histonin expressed produces an intact, natural
histonin. The AMP activity of the histonin produced in E. coli was identical to that of a synthetic histonin. With our expression system, 167 mg of histonin was obtained from 1 l of E. coli culture. These results may lead to a cost-effective solution for the mass production of AMPs that are toxic to a host. 相似文献
999.
Danuta Chołuj Romualda Karwowska Agnieszka Ciszewska Marta Jasińska 《Acta Physiologiae Plantarum》2008,30(5):679-687
Accumulation of various osmolytes was examined in plants of sugar beet cv. Janus grown under two soil water treatments: control
(60% of the field water capacity; FWC) and drought (30–35% FWC). The water shortage started on the 61st day after emergence
(DAE), at the stage of the beginning of tap-roots development and was imposed for 35 days. Osmotic potential of sugar beet
plant organs, particularly tap-roots, was decreased significantly as a consequence of a long-term drought. Water shortage
reduced univalent (K+, Na+) cations concentrations in the petioles and divalent (Ca2+, Mg2+) ions level in the mature and old leaves. Cation concentrations in the tap-roots were not affected by water shortage. The
ratio of univalent to divalent cations was significantly increased in young leaves and petioles as a consequence of drought.
Long-term water deficit caused a significant reduction of inorganic phosphorus (Pi) concentration in young and old leaves. Under the water stress condition, the concentration of proline was increased in all
individual plant organs, except proline concentration in the youngest leaves. Drought treatment caused a significant increase
of glycine betaine content in shoot without any change in tap-roots. Glucose concentrations were significantly increased only
in tap-roots as the effect of drought. In response to water shortage the accumulation of sucrose was observed in all the examined
leaves and tap-roots. Overall, a long-term drought activated an effective mechanism for osmotic adjustment both in the shoot
and in the root tissues which may be critical to survival rather than to maintain plant growth but sugar beet organs accumulate
different solutes as a response to water cessation. 相似文献
1000.
S. Y. Park Y. W. Kim H. K. Moon H. N. Murthy Y. H. Choi H. M. Cho 《Plant Cell, Tissue and Organ Culture》2008,93(3):341-346
The effect of phytohormones on the breaking of dormancy of axillary buds in Salix pseudolasiogyne and their subsequent proliferation from nodal explants were examined. Nodal explants obtained from a 20–year-old S. pseudolasiogyne tree were cultured either on woody plant basal medium (WPM) or WPM supplemented with benzyladenine (BA, 2.2/4.4 μM), zeatin
(1.1/2.2 μM), gibberillic acid (GA3, 2.9 and 14.5 μM), and GA3 + BA (2.9 + 4.4 μM). Although axillary shoots developed in all the media, a higher percentage bud break occurred on BA supplemented
media. To corroborate the results, endogenous levels of cytokinins [Cks, N
6-isopentenyladenine (iP), zeatin riboside (t-ZR), dihydrozeatinriboside (DHZR)] and abscisic acid (ABA) were determined. On BA supplemented media, the levels of zeatin
type (Z-type) of Cks were higher than those of isopentenyladenine type of Ck in the explants, while the ABA level was low.
Axillary shoots did not grow well and became necrotic upon subculture to fresh basal WPM. In order to improve shoot growth,
they were subcultured twice at a 4-week interval on to WPM supplemented with BA (2.2/4.4 μM), GA3 (1.4 μM), or GA3 + BA (1.4 + 4.4/2.9 + 4.4 μM). Maximal shoot growth (93%) was achieved on WPM supplemented with 2.2 μM BA. Comparative analyses
of endogenous Cks revealed that higher Cks (Z-type Cks) were present in actively growing shoots. Rooting was readily achieved
when the shoots were subcultured to WPM without phytohormones. The rooted plants were acclimatized well upon transplantation. 相似文献