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81.
Matsuki A Yamamoto S Nakagami H Aoki M Tamai K Matsumoto K Nakamura T Ogihara T Kaneda Y Morishita R 《Biochemical and biophysical research communications》2004,315(1):59-65
Recently, a novel therapeutic treatment for ischemic diseases using angiogenic growth factors to augment collateral artery development has been proposed. As intramuscular injection of naked human hepatocyte growth factor (HGF) plasmid DNA induced therapeutic angiogenesis in several animal test subjects, we have started a clinical trial to treat peripheral arterial disease. However, one might assume that over-expression of angiogenic growth factors could enhance tumor growth. To resolve this issue, we examined the over-expression of HGF in tumor bearing mice. Tumors on their backs were prepared with an intradermal inoculation of A431, human epidermoid cancer cells expressing c-Met. These mice were intramuscularly injected with human HGF plasmid or control plasmid into the femoral muscle. Human HGF concentration was increased only in the femoral muscle, but not in blood. Although recombinant HGF stimulated the growth of A431 cells in vitro, temporally and locally HGF elevation in hindlimb had no effect on tumor growth in mice. 相似文献
82.
Magnetic nanoparticles with surface modification enhanced gene delivery of HVJ-E vector 总被引:6,自引:0,他引:6
Morishita N Nakagami H Morishita R Takeda S Mishima F Terazono B Nishijima S Kaneda Y Tanaka N 《Biochemical and biophysical research communications》2005,334(4):1121-1126
To enter the realm of human gene therapy, a novel drug delivery system is required for efficient delivery of small molecules with high safety for clinical usage. We have developed a unique vector "HVJ-E (hemagglutinating virus of Japan-envelope)" that can rapidly transfer plasmid DNA, oligonucleotide, and protein into cells by cell-fusion. In this study, we associated HVJ-E with magnetic nanoparticles, which can potentially enhance its transfection efficiency in the presence of a magnetic force. Magnetic nanoparticles, such as maghemite, with an average size of 29 nm, can be regulated by a magnetic force and basically consist of oxidized Fe which is commonly used as a supplement for the treatment of anemia. A mixture of magnetite particles with protamine sulfate, which gives a cationic surface charge on the maghemite particles, significantly enhanced the transfection efficiency in an in vitro cell culture system based on HVJ-E technology, resulting in a reduction in the required titer of HVJ. Addition of magnetic nanoparticles would enhance the association of HVJ-E with the cell membrane with a magnetic force. However, maghemite particles surface-coated with heparin, but not protamine sulfate, enhanced the transfection efficiency in the analysis of direct injection into the mouse liver in an in vivo model. The size and surface chemistry of magnetic particles could be tailored accordingly to meet specific demands of physical and biological characteristics. Overall, magnetic nanoparticles with different surface modifications can enhance HVJ-E-based gene transfer by modification of the size or charge, which could potentially help to overcome fundamental limitations to gene therapy in vivo. 相似文献
83.
Wataru Saburi Hironori Hondoh Young-Min Kim Haruhide Mori Masayuki Okuyama Atsuo Kimura 《Biologia》2008,63(6):1000-1005
Dextran glucosidase from Streptococcus mutans (SMDG), an exo-type glucosidase of glycoside hydrolase (GH) family 13, specifically hydrolyzes an α-1,6-glucosidic linkage at the non-reducing ends of isomaltooligosaccharides and dextran. SMDG shows the highest sequence
similarity to oligo-1,6-glucosidases (O16Gs) among GH family 13 enzymes, but these enzymes are obviously different in terms
of substrate chain length specificity. SMDG efficiently hydrolyzes both short-and long-chain substrates, while O16G acts on
only short-chain substrates. We focused on this difference in substrate specificity between SMDG and O16G, and elucidated
the structure-function relationship of substrate chain length specificity in SMDG. Crystal structure analysis revealed that
SMDG consists of three domains, A, B, and C, which are commonly found in other GH family 13 enzymes. The structural comparison
between SMDG and O16G from Bacillus cereus indicated that Trp238, spanning subsites +1 and +2, and short β → α loop 4, are characteristic of SMDG, and these structural elements are predicted to be important for high activity toward
long-chain substrates. The substrate size preference of SMDG was kinetically analyzed using two mutants: (i) Trp238 was replaced
by a smaller amino acid, alanine, asparagine or proline; and (ii) short β → α loop 4 was exchanged with the corresponding loop of O16G. Mutant enzymes showed lower preference for long-chain substrates
than wild-type enzyme, indicating that these structural elements are essential for the high activity toward long-chain substrates,
as implied by structural analysis. 相似文献
84.
Birukawa N Ando H Goto M Kanda N Pastene LA Urano A 《Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology》2008,149(2):227-235
Urea transport in the kidney is important for the production of concentrated urine. This process is mediated by urea transporters (UTs) encoded by two genes, UT-A (Slc14a2) and UT-B (Slc14a1). Our previous study demonstrated that cetaceans produce highly concentrated urine than terrestrial mammals, and that baleen whales showed higher concentrations of urinary urea than sperm whales. Therefore, we hypothesized that cetaceans have unique actions of UTs to maintain fluid homeostasis in marine habitat. Kidney samples of common minke (Balaenoptera acutorostrata), sei (B. borealis), Bryde's (B. brydei) and sperm whales (Physeter macrocephalus) were obtained to determine the nucleotide sequences of mRNAs encoding UT. The sequences of 2.5-kb cDNAs encode 397-amino acid proteins, which are 90-94% identical to the mammalian UT-A2s. Two putative glycosylation sites are conserved between the whales and the terrestrial mammals, whereas consensus sites for protein kinases are not completely conserved; only a single protein kinase A consensus site was identified in the whale UT-A2s. Two protein kinase C consensus sites are present in the baleen whale UT-A2s, however, a single protein kinase C consensus site was identified in the sperm whale UT-A2. These different phosphorylation sites of whale UT-A2s may result in the high concentrations of urinary urea in whales, by reflecting their urea permeability. 相似文献
85.
Shigeki Kobayashi Takehisa Susa Hironori Ishiguchi Takeki Myoren Wakako Murakami Takayoshi Kato Masakazu Fukuda Akihiro Hino Takeshi Suetomi Makoto Ono Hitoshi Uchinoumi Hiroki Tateishi Mamoru Mochizuki Tetsuro Oda Shinichi Okuda Masahiro Doi Takeshi Yamamoto Masafumi Yano 《PloS one》2015,10(1)
Objectives
The purpose of this study was to investigate whether adding a low-dose β1-blocker to milrinone improves cardiac function in failing cardiomyocytes and the underlying cardioprotective mechanism.Background
The molecular mechanism underlying how the combination of low-dose β1-blocker and milrinone affects intracellular Ca2+ handling in heart failure remains unclear.Methods
We investigated the effect of milrinone plus landiolol on intracellular Ca2+ transient (CaT), cell shortening (CS), the frequency of diastolic Ca2+ sparks (CaSF), and sarcoplasmic reticulum Ca2+ concentration ({Ca2+}SR) in normal and failing canine cardiomyocytes and used immunoblotting to determine the phosphorylation level of ryanodine receptor (RyR2) and phospholamban (PLB).Results
In failing cardiomyocytes, CaSF significantly increased, and peak CaT and CS markedly decreased compared with normal myocytes. Administration of milrinone alone slightly increased peak CaT and CS, while CaSF greatly increased with a slight increase in {Ca2+}SR. Co-administration of β1-blocker landiolol to failing cardiomyocytes at a dose that does not inhibit cardiomyocyte function significantly decreased CaSF with a further increase in {Ca2+}SR, and peak CaT and CS improved compared with milrinone alone. Landiolol suppressed the hyperphosphorylation of RyR2 (Ser2808) in failing cardiomyocytes but had no effect on levels of phosphorylated PLB (Ser16 and Thr17). Low-dose landiolol significantly inhibited the alternans of CaT and CS under a fixed pacing rate (0.5 Hz) in failing cardiomyocytes.Conclusion
A low-dose β1-blocker in combination with milrinone improved cardiac function in failing cardiomyocytes, apparently by inhibiting the phosphorylation of RyR2, not PLB, and subsequent diastolic Ca2+ leak. 相似文献86.
Species of predatory Coleoptera have become abundant in new geographic regions recently, raising concerns for invaded ecosystems.
We address this topic by focusing on invasive alien ladybird beetles (Coccinellidae; known also as ladybugs). Humans appear
directly or indirectly responsible for all or most ladybird invasions. Factors hypothesized to have promoted ladybird invasions
include genetic diversity (e.g., for polymorphism), phenotypic plasticity, adaptation and genetic shift, generalized diet
and habitat preferences, flexible life history and reproduction, large body size, and release from enemies. Factors such as
climate, habitat and prey availability, and biotic resistance may sometimes prevent or slow ladybird invasions. Indigenous
species (e.g., herbivores) may suffer from invasions, and biological control programs may be affected. Species of indigenous
ladybirds throughout the world are reported to have declined in abundance following ladybird invasions, with increased competition
and/or intraguild predation most often hypothesized or inferred. Similar recent studies especially of ground beetles (Carabidae)
also make clear the potential of invasive alien predatory Coleoptera to disrupt invaded natural and agricultural ecosystems. 相似文献
87.
ATP-Activated Nonselective Cation Current in NG108-15 Cells 总被引:5,自引:0,他引:5
Hiromi Kaiho Junko Kimura Isao Matsuoka Tadanori Kumasaka Hironori Nakanishi 《Journal of neurochemistry》1996,67(1):398-406
Abstract: ATP (1 mM) induced a biphasic increase in intracellular Ca2+ concentration ([Ca2+]i), i.e., an initial transient increase decayed to a level of sustained increase, in NG108-15 cells. The transient increase was inhibited by a phospholipase C inhibitor, 1-[6-[[17β-3-methoxyestra-1,3,5(10)-trien-17-yl]amino]hexyl]-1H-pyrrole-2,5-dione (U73122), whereas the sustained increase was abolished by removal of external Ca2+. We examined the mechanism of the ATP-elicited sustained [Ca2+]i increase using the fura-2 fluorescent method and the whole-cell patch clamp technique. ATP (1 mM) induced a membrane current with the reversal potential of 12.5 ± 0.8 mV (n = 10) in Tyrode external solution. The EC50 of ATP was ~0.75 mM. The permeability ratio of various cations carrying this current was Na+ (defined as 1) > Li+ (0.92 ± 0.01; n = 5) > K+ (0.89 ± 0.03; n = 6) > Rb+ (0.55 ± 0.02; n = 6) > Cs+ (0.51 ± 0.01; n = 5) > Ca2+ (0.22 ± 0.03; n = 3) > N-methyl-d -glucamine (0.13 ± 0.01; n = 5), suggesting that ATP activated a nonselective cation current. The ATP-induced current was larger at lower concentrations of external Mg2+. ATP analogues that induced the current were 2-methylthio-ATP (2MeSATP), benzoylbenzoic-ATP, adenosine 5′-thiotriphosphate (ATPγS), and adenosine 5′-O-(2-thiodiphosphate), but not adenosine, ADP, α,β-methylene-ATP (AMPCPP), β,γ-methylene-ATP (AMPPCP), or UTP. Concomitant with the current data, 2MeSATP and ATPγS, but not AMPCPP or AMPPCP, increased the sustained [Ca2+]i increase. We conclude that ATP activates a class of Ca2+-permeable nonselective cation channels via the P2z receptor in NG108-15 cells. 相似文献
88.
Mohammed Abdel-Wahab Masahiro Miyashita Atsushi Kitanaka Hironori Juichi Moustafa Sarhan Maged Fouda 《Bioscience, biotechnology, and biochemistry》2016,80(10):1879-1882
Over 200 components with molecular mass ranging mainly from 400 to 4000 Da were characterized from the venom of the vermivorous cone snail Conus fulgetrum that inhabit Egyptian Red Sea. One major component having a molecular mass of 2946 Da was purified by HPLC, and its primary structure was determined by a combination of Edman degradation and MS/MS analysis. 相似文献
89.
90.
The production of higher alcohols by engineered bacteria has received significant attention. The budding yeast, Saccharomyces cerevisiae, has considerable potential as a producer of higher alcohols because of its capacity to naturally fabricate fusel alcohols, in addition to its robustness and tolerance to low pH. However, because its natural productivity is not significant, we considered a strategy of genetic engineering to increase production of the branched-chain higher alcohol isobutanol, which is involved in valine biosynthesis. Initially, we overexpressed 2-keto acid decarboxylase (KDC) and alcohol dehydrogenase (ADH) in S. cerevisiae to enhance the endogenous activity of the Ehrlich pathway. We then overexpressed Ilv2, which catalyzes the first step in the valine synthetic pathway, and deleted the PDC1 gene encoding a major pyruvate decarboxylase with the intent of altering the abundant ethanol flux via pyruvate. Through these engineering steps, along with modification of culture conditions, the isobutanol titer of S. cerevisiae was elevated 13-fold, from 11 mg/l to 143 mg/l, and the yield was 6.6 mg/g glucose, which is higher than any previously reported value for S. cerevisiae. 相似文献