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971.
Mai Tsuchiya Yuka Nakajima Naoya Hirata Tamaki Morishita Hiroyuki Kishimoto Yasunari Kanda Keiji Kimura 《Biochemical and biophysical research communications》2014
Cancer stem cells (CSCs) have several distinctive characteristics, including high metastatic potential, tumor-initiating potential, and properties that resemble normal stem cells such as self-renewal, differentiation, and drug efflux. Because of these characteristics, CSC is regarded to be responsible for cancer progression and patient prognosis. In our previous study, we showed that a ubiquitin E3 ligase carboxyl terminus of Hsc70-interacting protein (CHIP) suppressed breast cancer malignancy. Moreover, a recent clinical study reported that CHIP expression levels were associated with favorable prognostic parameters of patients with breast cancer. Here we show that CHIP suppresses CSC properties in a population of breast cancer cells. CHIP depletion resulted in an increased proportion of CSCs among breast cancers when using several assays to assess CSC properties. From our results, we propose that inhibition of CSC properties may be one of the functions of CHIP as a suppressor of cancer progression. 相似文献
972.
Satoshi Inouye Jun-ichi Sato Yuiko Sahara-Miura Suguru Yoshida Takamitsu Hosoya 《Biochemical and biophysical research communications》2014
To characterize the luminescence properties of nanoKAZ, a 16 amino acid substituted mutant of the catalytic 19 kDa protein (KAZ) of Oplophorus luciferase, the effects of each mutated amino acid were investigated by site-specific mutagenesis. All 16 single substituted KAZ mutants were expressed in Escherichia coli cells and their secretory expressions in CHO-K1 cells were also examined using the signal peptide sequence of Gaussia luciferase. Luminescence activity of KAZ was significantly enhanced by single amino acid substitutions at V44I, A54I, or Y138I. Further, the triple mutant KAZ-V44I/A54I/Y138I, named eKAZ, was prepared and these substitutions synergistically enhanced luminescence activity, showing 66-fold higher activity than wild-KAZ and also 7-fold higher activity than nanoKAZ using coelenterazine as a substrate. Substrate specificity of eKAZ for C2- and/or C6-modified coelenterazine analogues was different from that of nanoKAZ, indicating that three amino acid substitutions may be responsible for the substrate recognition of coelenterazine to increase luminescence activity. In contrast, these substitutions did not stimulate protein secretion from CHO-K1 cells, suggesting that the folded-protein structure of KAZ might be different from that of nanoKAZ. 相似文献
973.
Fumiyuki Nakagawa Katsutaro Morino Satoshi Ugi Atsushi Ishikado Keiko Kondo Daisuke Sato Shiho Konno Ken-ichi Nemoto Chisato Kusunoki Osamu Sekine Akihiro Sunagawa Masanori Kawamura Noriko Inoue Yoshihiko Nishio Hiroshi Maegawa 《Biochemical and biophysical research communications》2014
It has recently been reported that expression of heme oxygenase-1 (HO-1) plays a protective role against many diseases. Furthermore, n-3 polyunsaturated fatty acids (PUFAs) were shown to induce HO-1 expression in several cells in vitro, and in a few cases also in vivo. However, very few reports have demonstrated that n-3 PUFAs induce HO-1 in vivo. 相似文献
974.
Masatomo So Yuto Kimura Keiichi Yamaguchi Toshihiko Sugiki Toshimichi Fujiwara Cesar Aguirre Kensuke Ikenaka Hideki Mochizuki Yasushi Kawata Yuji Goto 《Protein science : a publication of the Protein Society》2021,30(8):1701
Amyloid fibril formation is associated with various amyloidoses, including neurodegenerative diseases such as Alzheimer''s and Parkinson''s diseases. Amyloid fibrils form above the solubility of amyloidogenic proteins or peptides upon breaking supersaturation, followed by a nucleation and elongation mechanism, which is similar to the crystallization of solutes. Many additives, including salts, detergents, and natural compounds, promote or inhibit amyloid formation. However, the underlying mechanisms of the opposing effects are unclear. We examined the effects of two polyphenols, that is, epigallocatechin gallate (EGCG) and kaempferol‐7─O─glycoside (KG), with high and low solubilities, respectively, on the amyloid formation of α‐synuclein (αSN). EGCG and KG inhibited and promoted amyloid formation of αSN, respectively, when monitored by thioflavin T (ThT) fluorescence or transmission electron microscopy (TEM). Nuclear magnetic resonance (NMR) analysis revealed that, although interactions of αSN with soluble EGCG increased the solubility of αSN, thus inhibiting amyloid formation, interactions of αSN with insoluble KG reduced the solubility of αSN, thereby promoting amyloid formation. Our study suggests that opposing effects of polyphenols on amyloid formation of proteins and peptides can be interpreted based on the solubility of polyphenols. 相似文献
975.
Effects of nitrite inhibition on anaerobic ammonium oxidation 总被引:6,自引:0,他引:6
Yuya Kimura Kazuichi Isaka Futaba Kazama Tatsuo Sumino 《Applied microbiology and biotechnology》2010,86(1):359-365
In order to assess the stability of nitrogen removal systems utilizing anaerobic ammonium oxidation (anammox), it is necessary
to study the toxic effects of nitrite on these biochemical reactions. In this study, the effects of nitrite on anammox bacteria
entrapped in gel carriers were investigated using batch and continuous feeding tests. The results showed that the nitrite
concentration in a reactor must be less than 274-mg N/L in order to prevent a decrease in the anammox activity, which occurred
when the gel carriers were soaked in nitrite solutions with concentrations greater than 274-mg N/L in a batch test. In a continuous
feeding test, nitrite inhibition was not observed at low concentrations of nitrite. However, the anammox activity decreased
to 10% when the nitrite concentration increased to 750-mg N/L over a 7-day period in the reactor. In addition, it was shown
that the effects of nitrogen on the anammox reaction were reversible because the anammox activity completely recovered within
3 days when the influent nitrite concentration was decreased to less than 274-mg N/L. 相似文献
976.
Fujii S Maeda H Tomokiyo A Monnouchi S Hori K Wada N Akamine A 《Cell and tissue research》2010,342(2):233-242
Periodontal ligament (PDL) is a specialized connective tissue that influences the lifespan of the tooth. Transforming growth factor-β1 (TGF-β1) is a multifunctional cytokine, but little is known about the effects of TGF-β1 on PDL cells. Our aim has been to demonstrate the expression of TGF-β1 in rat PDL tissues and to evaluate its effects on the proliferation and gene expression in human PDL cells (HPLCs) and a human PDL stem/progenitor cell line, line 1-11, that we have recently developed. The expression of TGF-β1 in the entire PDL tissue was confirmed immunohistochemically, and both HPLCs and cell line 1-11 expressed mRNA from the TGF-β1, TGF-β type I receptor, and TGF-β type II receptor genes. Although exogenous TGF-β1 stimulated the proliferation of HPLCs, it did not upregulate the expression of alpha-smooth muscle actin (α-SMA), type I collagen (Col I), or fibrillin-1 (FBN1) mRNA or of α-SMA protein in HPLCs, whereas expression for these genes was attenuated by an anti-TGF-β1 neutralizing antibody. In contrast, exogenous TGF-β1 reduced the proliferation of cell line 1-11, although it upregulated the expression of α-SMA, Col I, and FBN1 mRNA and of α-SMA protein in this cell line. In addition, interleukin-1 beta stimulation significantly reduced the expression of TGF-β1 mRNA and protein in HPLCs. Thus, TGF-β1 seems to play an important role in inducing fibroblastic differentiation of PDL stem/progenitor cells and in maintaining the PDL apparatus under physiological conditions. 相似文献
977.
978.
Hermansyah Walter A. Laviña Minetaka Sugiyama Yoshinobu Kaneko Satoshi Harashima 《Archives of microbiology》2010,192(3):157-165
The double disruptant of the S. cerevisiae protein phosphatase (PPase) genes, PTP2 (phosphotyrosine-specific PPase) and MSG5 (phosphotyrosine and phosphothreonine/serine-PPase) causes calcium-sensitive growth (Cas). Previous study using Fluorescent-activated cell sorting (FACS) analysis showed that this growth defect with calcium occurs
at G1–S transition in the cell cycle. We discovered that six non-essential protein kinase (PKase) disruptions (Δbck1, Δmkk1, Δslt2/Δmpk1, Δmck1, Δssk2 and Δyak1) suppressed the Cas-phenotype of the Δptp2 Δmsg5 double disruptant. Bck1p, Mkk1p and Slt2p are components of the mitogen-activated protein kinase (MAPK) cascade of cell wall
integrity pathway (Slt2 pathway), and Mck1p is its down regulator. Ssk2p is the MAPK kinase kinase of the high-osmolarity
glycerol (HOG) pathway, while Yak1p is a negative regulator for the cAMP-dependent PKA pathway. FACS analysis revealed that
only the disruption of Δssk2 and Δyak1 but not Δbck1, Δmkk1, Δslt2 and Δmck1 was able to suppress the delayed G1–S transition, suggesting that suppression of the growth defect is not always accompanied
by suppression of the G1–S transition delay. The discovery of these PKases as suppressors revealed that in addition to the
previously anticipated Slt2 pathway, HOG, Yak1p and Mck1p regulatory pathways may also be involved in the calcium sensitivity of the Δptp2 Δmsg5 double disruptant. 相似文献
979.
Takehito Kemuriyama Hiroyuki Ohta Yoshiaki Sato Satoshi Maruyama Megumi Tandai-Hiruma Kazuo Kato Yasuhiro Nishida 《Bio Systems》2010,101(2):144-147
To assess sympathetic variability in chronic heart failure (CHF), we evaluated a distribution of inter-spike intervals (ISIs) in renal sympathetic nerve activity (RSNA) in salt-sensitive hypertension-induced CHF (DSSH-CHF) rats. Dahl salt-sensitive rats were fed an 8% NaCl diet for 9 weeks to induce salt-sensitive hypertension-induced CHF. ISIs in RSNA were obtained from chronically instrumented conscious rats, and counts (frequency) and ranks of ISIs in RSNA were plotted with a histogram. We found that ISIs in RSNA followed a power-law distribution in rats, and the power-law distribution of ISIs for RSNA in DSSH-CHF rats was significantly different from that in normal rats. These results indicated that sympathetic variability may be significantly different between salt-sensitive hypertension-induced CHF and healthy individuals, which suggests that sympathetic variability may be used to predict abnormality of the sympathetic regulatory system. 相似文献
980.