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101.
102.
K.-T. Lee T. Suzuki T. Yamakawa T. Kodama Y. Igarashi K. Shimomura 《Plant cell reports》1999,18(7-8):567-571
A scale up of transformed root cultures of Atropa belladonna from a 300-ml flask to a 30-l tank was accomplished without any reduction in alkaloid productivity. Cutting treatment of
seed cultures showed no distinct effect on root growth, morphology, and alkaloid content in conical flasks during 1 month
of culture. Randomly cut roots thus grown were further cultivated in 3-l and 30-l modified stirred bioreactors for a scale-up
culture. After 1 month of culture, 1490 mg of tropane alkaloids was produced by a 30-l culture of A. belladonna transformed roots. These roots contained the same level of atropine (5.4 mg/ g dw) as the roots of this plant grown in the
field for 12 months and still contained a considerable amount of other alkaloids including 1.6 mg/g dw of 6-β-hydroxyhyoscyamine, 0.9 mg/g dw of scopolamine, and 2.0 mg/g dw of littorine.
Received: 12 June 1998 / Revision received: 31 August 1998 / Accepted: 27 October 1998 相似文献
103.
Satoko Isogai Kaori Touno Koichiro Shimomura 《In vitro cellular & developmental biology. Plant》2008,44(3):216-220
The internodes of Cephaelis ipecacuanha elongated when cultured on Gamborg B5 solid medium supplemented with 0.5 or 1 mg/L gibberellic acid (GA3). The size of the elongated internode doubled in length compared to the untreated shoots, and the adventitious shoots formed
on the elongated internodes. The shoots grew easily into plantlets without the use of auxin for rooting. The ex vitro regenerates cultivated in the greenhouse showed normal characteristics. Emetic alkaloids were detected in the leaves of in vitro shoots and the roots of regenerates cultivated in the greenhouse. This method using GA3 propagated numerous plants at a rate of more than 100 times compared to the method without GA3. 相似文献
104.
Takeshi Shimomura Tetsuji Itoh Touru Sumiya Fujio Mizukami Masatoshi Ono 《Enzyme and microbial technology》2009,45(6-7):443-448
Acetylcholine sensor is successfully prepared by using immobilized enzymes, i.e., acetylcholinesterase and choline oxidase within separate hybrid mesoporous silica membranes with 12 nm pore diameter (F127M). The measurement was based on the detection of hydrogen peroxide produced by two sequential enzyme reactions. The determination range and the response time are 6.0–800 μM and within approximately 3 min, respectively. The sensor is very stable compared to free enzymes and 80% of the initial response was maintained even after storage for 80 days. These results show that two enzymes are successfully immobilized and well stabilized, and at the same time, two sequential enzyme reactions efficiently proceed within the separate hybrid mesoporous membranes. Further, we studied the possible detection of organophosphorus pesticides in terms of the inhibition of acetylcholinesterase activity, i.e., the decrease of current response, and demonstrated that the nanomolar concentrations of pesticide (DZN-oxon) can be detected with our sensor. 相似文献
105.
Yasuhiko Nakagawa Shinji Kihara Tohru Funahashi Iichiro Shimomura 《Biochemical and biophysical research communications》2009,382(1):183-863
We have demonstrated that adiponectin has anti-atherosclerotic properties. We also reported hypoadiponectinemia and nocturnal reduction in circulating adiponectin concentrations in patients of severe obstructive sleep apnea-hypopnea syndrome (OSAS). OSAS is often complicated with pulmonary hypertension. In this study, we investigated the effect of adiponectin on chronic hypoxia-induced pulmonary arterial remodeling in mice. Exposure of mice to 3-weeks sustained hypoxia (10% O2) resulted in significant accumulation of adiponectin in pulmonary arteries. The percentage media wall thickness (%MT), representing pulmonary arterial remodeling, under hypoxic condition, was greater in adiponectin-knockout mice than wild-type mice. Overexpression of adiponectin significantly decreased hypoxia-induced pulmonary arterial wall thickening and right ventricular hypertrophy. These findings demonstrate for the first time that overexpression of adiponectin suppresses the development of hypoxic-induced pulmonary remodeling, and that adiponectin may combat a new strategy for pulmonary vascular changes that underlie pulmonary hypertension in OSAS. 相似文献
106.
Yuki Nakayama Akiko Yamamoto Masaki Tanaka Atsunori Fukuhara Iichiro Shimomura 《Biochemical and biophysical research communications》2009,379(2):288-292
Rho GTPase regulates actin cytoskeleton organization and assembly in many cell types, however, its significance in adipose tissue is not well characterized. Here, we demonstrate high RhoA activity in adipose tissues of C57BL/6J mice. To determine the effect of RhoA activation on 3T3-L1 cells, stable cell lines overexpressing G14VRhoA fused to destabilizing domain of FKBP12 (DD-G14VRhoA-L1) were generated. Treatment of DD-G14VRhoA-L1 cells with Shield1 following their differentiation into adipocytes, resulted in the appearance of thick cortical actin filaments, and increased the mRNA expression levels of plasminogen activator inhibitor type-1 (PAI-1) and monocyte chemoattractant protein-1 (MCP-1). The induction of PAI-1 and MCP-1 was inhibited by treatment with a Rho-associated kinase (ROCK) inhibitor, Y-27632. In 3T3-L1 adipocytes, tumor necrosis factor-α activated RhoA and increased mRNA expression of PAI-1 and MCP-1, and their treatment with Y-27632 partially inhibited these changes. The results indicate that RhoA-ROCK pathway induces inflammatory cytokine expression in adipocytes. 相似文献
107.
Ishiguro H Katano Y Nakano I Ishigami M Hayashi K Honda T Goto H Bajotto G Maeda K Shimomura Y 《Life sciences》2006,79(8):737-743
Leucine stimulates protein synthesis by modulating the mammalian target of rapamycin (mTOR) signaling pathway. We hypothesized that promotion of the branched-chain amino acid (BCAA) catabolism might influence the leucine-induced protein synthesis. Clofibric acid (an active metabolite of clofibrate) is known to promote the BCAA catabolism by activation of branched-chain alpha-keto acid dehydrogenase complex (BCKDC), the rate-limiting enzyme of the BCAA catabolism. In the present study, we examined the phosphorylation state of mTOR, eukaryotic initiation factor 4E-binding protein-1 (4E-BP1), and ribosomal protein S6 kinase 1 (S6K1) in liver of rats with or without activation of the BCKDC by clofibrate treatment. Clofibrate-treated rats were prepared by oral administration of clofibrate 5 h before sacrifice. In order to stimulate phosphorylation of components in the mTOR signaling pathway, rats were orally administered with leucine 1 h before sacrifice. Clofibrate treatment almost fully activated hepatic BCKDC and significantly decreased the plasma leucine concentration in rats without leucine administration, resulting in decreased mTOR and 4E-BP1 phosphorylation. Similarly, in rats administered with leucine, clofibrate treatment attenuated the predicted increase in plasma leucine concentration as well as the phosphorylation of mTOR, 4E-BP1, and S6K1. These results suggest that BCAA catabolism enhanced by clofibrate treatment has significant influences on the leucine-induced activation of translation initiation processes. 相似文献
108.
Helicobacter pylori is a unique bacterial species that assimilates various steroids as membrane lipid components. Our group has recently found, however, that certain steroids may impair the viability of H. pylori. In this study, we go on to reveal that estradiol, androstenedione, and progesterone (PS) all have the potential to inhibit the growth of H. pylori. Of these three steroid hormones, progesterone demonstrated the most effective anti-H. pylori action. 17α-hydroxyprogesterone caproate (17αPSCE), a synthetic progesterone derivative, had a much stronger anti-H. pylori action than progesterone, whereas 17α-hydroxyprogesterone, a natural progesterone derivative, completely failed to inhibit the growth of the organism. Progesterone and 17αPSCE were both found to kill H. pylori through their bacteriolytic action. Among five bacterial species investigated, H. pylori was the only species susceptible to the bactericidal action of progesterone and 17αPSCE. The other four species, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epiderimidis, all resisted this action. Progesterone and free-cholesterol (FC) obstructed each other's effects against the H. pylori cell. Taken in sum, these results suggest that progesterone and FC may bind to the identical region on the H. pylori cell surface. We expect these findings to contribute to the development of a novel anti-H. pylori steroidal agent. 相似文献
109.
Asano R Ikoma K Shimomura I Taki S Nakanishi T Umetsu M Kumagai I 《The Journal of biological chemistry》2011,286(3):1812-1818
Diabodies (Dbs) and tandem single-chain variable fragments (taFv) are the most widely used recombinant formats for constructing small bispecific antibodies. However, only a few studies have compared these formats, and none have discussed their binding kinetics and cross-linking ability. We previously reported the usefulness for cancer immunotherapy of a humanized bispecific Db (hEx3-Db) and its single-chain format (hEx3-scDb) that target epidermal growth factor receptor and CD3. Here, we converted hEx3-Db into a taFv format to investigate how format affects the function of a small bispecific antibody; our investigation included a cytotoxicity assay, surface plasmon resonance spectroscopy, thermodynamic analysis, and flow cytometry. The prepared taFv (hEx3-taFv) showed an enhanced cytotoxicity, which may be attributable to a structural superiority to the diabody format in cross-linking target cells but not to differences in the binding affinities of the formats. Comparable cross-linking ability for soluble antigens was observed among hEx3-Db, hEx3-scDb, and hEx3-taFv with surface plasmon resonance spectroscopy. Furthermore, drastic increases in cytotoxicity were found in the dimeric form of hEx3-taFv, especially when the two hEx3-taFv were covalently linked. Our results show that converting the format of small bispecific antibodies can improve their function. In particular, for small bispecific antibodies that target tumor and immune cells, a functional orientation that avoids steric hindrance in cross-linking two target cells may be important in enhancing the growth inhibition effect. 相似文献
110.