Language：English   Publishing type：Research paper (scientific journal)  

The increased incidence of obesity in the global population has increased the risk of several chronic inflammation-related diseases, including non-alcoholic steatohepatitis (NASH)-hepatocellular carcinoma (HCC). The progression from NASH to HCC involves a virus-independent liver carcinogenic mechanism; however, we currently lack effective treatment and prevention strategies. Several reports have suggested that fecal volatile organic compounds (VOCs) are strongly associated with NASH-HCC; therefore, we explored the biomarkers involved in its pathogenesis and progression. Fecal samples collected from control and NASH-HCC model STAM mice were subjected to headspace autosampler gas chromatography-electron ionization-mass spectrometry. Non-target profiling analysis identified diacetyl (2,3-butandione) as a fecal VOC that characterizes STAM mice. Although fecal diacetyl levels were correlated with the HCC in STAM mice, diacetyl is known as a cytotoxic/tissue-damaging compound rather than genotoxic or mutagenic; therefore, we examined the effect of bioactivity associated with NASH progression. We observed that diacetyl induced several pro-inflammatory molecules, including tumor necrosis factor-α, cyclooxygenase-2, monocyte chemoattractant protein-1, and transforming growth factor-β, in mouse macrophage RAW264.7 and Kupffer KPU5 cells. Additionally, we observed that diacetyl induced α-smooth muscle actin, one of the hallmarks of fibrosis, in an ex vivo cultured hepatic section, but not in in vitro hepatic stellate TWNT-1 cells. These results suggest that diacetyl would be a potential biomarker of fecal VOC in STAM mice, and its ability to trigger the macrophage-derived inflammation and fibrosis may partly contribute to NASH-HCC carcinogenesis.

DOI： 10.1038/s41598-023-36091-7

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Publishing type：Research paper (scientific journal)   Publisher：Frontiers Media SA  

Sterol regulatory element-binding proteins (SREBPs) are key transcription factors that control fatty acid and cholesterol metabolism. As the major SREBP isoform in macrophages, SREBP1a is also required for inflammatory and phagocytotic functions. However, it is insufficiently understood how SREBP1a is activated by the innate immune response in macrophages. Here, we show that mouse caspase-11 is a novel inflammatory activator of SREBP1a in macrophages. Upon LPS treatment, caspase-11 was found to promote the processing of site-1 protease (S1P), an enzyme that mediates the cleavage and activation of SREBP1. We also determined that caspase-11 directly associates with S1P and cleaves it at a specific site. Furthermore, deletion of the Casp4 gene, which encodes caspase-11, impaired the activation of S1P and SREBP1 as well as altered the expression of genes regulated by SREBP1 in macrophages. These results demonstrate that the caspase-11/S1P pathway activates SREBP1 in response to LPS, thus regulating subsequent macrophage activation.

DOI： 10.3389/fimmu.2023.1009973

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Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1002/2211-5463.13526

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/2211-5463.13526

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Growing evidence has been accumulated to show the anticancer effects of daily consumption of polyphenols. These dietary polyphenols include chlorogenic acid, curcumin, epigallocatechin-3-O-gallate, genistein, quercetin, and resveratrol. These polyphenols have similar chemical and biological properties in that they can act as antioxidants and exert the anticancer effects via cell signaling pathways involving their reactive oxygen species (ROS)-scavenging activity. These polyphenols may also act as pro-oxidants under certain conditions, especially at high concentrations. Epigenetic modifications, including dysregulation of noncoding RNAs (ncRNAs) such as microRNAs, long noncoding RNAs, and circular RNAs are now known to be involved in the anticancer effects of polyphenols. These polyphenols can modulate the expression/activity of the component molecules in ROS-scavenger-triggered anticancer pathways (RSTAPs) by increasing the expression of tumor-suppressive ncRNAs and decreasing the expression of oncogenic ncRNAs in general. Multiple ncRNAs are similarly modulated by multiple polyphenols. Many of the targets of ncRNAs affected by these polyphenols are components of RSTAPs. Therefore, ncRNA modulation may enhance the anticancer effects of polyphenols via RSTAPs in an additive or synergistic manner, although other mechanisms may be operating as well.

DOI： 10.3390/antiox11122352

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Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

Drug repositioning is a strategy for repurposing the approved or investigational drugs that are outside the scope of the original medical indication. Memantine is used as a non‑competitive N‑methyl‑D‑aspartate receptor antagonist to prevent glutamate‑mediated excitotoxicity in Alzheimer's disease, and is one of the promising agents which is utilized for the purpose of cancer therapy. However, the association between memantine and Golgi glycoprotein 1 (GLG1), an intracellular fibroblast growth factor receptor, in cancers has not yet been clarified. The present study analyzed the expression and location of GLG1 in tumor cells treated with memantine. Memantine was found to suppress the growth of malignant glioma and breast cancer cells in a concentration‑dependent manner. The mRNA expression of GLG1 was upregulated in a concentration‑dependent manner, and the splicing variant profiles were altered in all cell lines examined. The results of western blot analysis revealed an increase in the full‑length and truncated forms of GLG1. Moreover, GLG1 spread in the cytosol of memantine‑treated cells, whereas it localized in the Golgi apparatus in control cells. Since GLG1 functions as a decoy FGF receptor, the modulation of GLG1 may prove to be one of the mechanisms underlying the cancer‑suppressive effects of memantine.

DOI： 10.3892/ijo.2022.5370

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Language：English   Publishing type：Research paper (scientific journal)  

Epidemiological studies have shown that consumption of green tea, coffee, wine, and curry may contribute to a reduced risk of various cancers. However, there are some cancer site-specific differences in their effects; for example, the consumption of tea or wine may reduce bladder cancer risk, whereas coffee consumption may increase the risk. Animal and cell-based experiments have been used to elucidate the anticancer mechanisms of these compounds, with reactive oxygen species (ROS)-based mechanisms emerging as likely candidates. Chlorogenic acid (CGA), curcumin (CUR), epigallocatechin gallate (EGCG), and resveratrol (RSV) can act as antioxidants that activate AMP-activated protein kinase (AMPK) to downregulate ROS, and as prooxidants to generate ROS, leading to the downregulation of NF-κB. Polyphenols can modulate miRNA (miR) expression, with these dietary polyphenols shown to downregulate tumor-promoting miR-21. CUR, EGCG, and RSV can upregulate tumor-suppressing miR-16, 34a, 145, and 200c, but downregulate tumor-promoting miR-25a. CGA, EGCG, and RSV downregulate tumor-suppressing miR-20a, 93, and 106b. The effects of miRs may combine with ROS-mediated pathways, enhancing the anticancer effects of these polyphenols. More precise analysis is needed to determine how the different modulations of miRs by polyphenols relate to the cancer site-specific differences found in epidemiological studies related to the consumption of foods containing these polyphenols.

DOI： 10.1080/10408398.2022.2038540

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Tea and coffee are consumed worldwide and epidemiological and clinical studies have shown their health beneficial effects, including anti-cancer effects. Epigallocatechin gallate (EGCG) and chlorogenic acid (CGA) are the major components of green tea polyphenols and coffee polyphenols, respectively, and believed to be responsible for most of these effects. Although a large number of cell-based and animal experiments have provided convincing evidence to support the anti-cancer effects of green tea, coffee, EGCG, and CGA, human studies are still controversial and some studies have suggested even an increased risk for certain types of cancers such as esophageal and gynecological cancers with green tea consumption and bladder and lung cancers with coffee consumption. The reason for these inconsistent results may have been arisen from various confounding factors. Cell-based and animal studies have proposed several mechanisms whereby EGCG and CGA exert their anti-cancer effects. These components appear to share the common mechanisms, among which one related to reactive oxygen species is perhaps the most attractive. Meanwhile, EGCG and CGA have also different target molecules which might explain the site-specific differences of anti-cancer effects found in human studies. Further studies will be necessary to clarify what is the mechanism to cause such differences between green tea and coffee.

DOI： 10.3390/molecules25194553

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Authorship：Lead author   Language：English   Publishing type：Part of collection (book)   Publisher：Springer Science and Business Media B.V.  

A number of epidemiological studies and clinical trials have reported the beneficial effects of both green tea and coffee on human health, including anticancer, anti-obesity, antidiabetic, antihypertensive, and hepatoprotective effects. Furthermore, these findings in humans are supported by cell-based and animal experiments. These effects have been attributed to epigallocatechin gallate (EGCG) in green tea and chlorogenic acid (CGA) in coffee, which have been proposed to function via various mechanisms of action, the most important of which appears to implicate reactive oxygen species (ROS). Both EGCG and CGA can exert conflicting dual actions as an antioxidant and a prooxidant. Their antioxidative action can scavenge ROS, leading to downregulation of nuclear factor-κB to produce various favorable effects such as anti-inflammatory effects and cancer cell apoptosis. The prooxidant actions, however, can promote the generation of ROS leading to the activation of 5’AMP-dependent protein kinase, which modulates various enzymes and factors with beneficial roles. At present, it remains unclear how EGCG and CGA can be directed to act as either a prooxidant or an antioxidant, although their cellular concentrations, the presence of metal cations such as Cu+ and Fe++, and the redox state of the cells appear to be important factors. Notably, several human studies did not report the beneficial health effects of green tea and coffee. The inconsistent results may have been caused by various confounding factors including smoking, intestinal microbiota, and genetic factors. This chapter examines the current information on these properties of green tea and coffee with the aim of improving the understanding of a way to enjoy healthy longevity.

DOI： 10.1007/978-3-319-78030-6_14

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Language：English   Publisher：MDPI AG  

Green tea has been shown to have beneficial effects on many diseases such as cancer, obesity, inflammatory diseases, and neurodegenerative disorders. The major green tea component, epigallocatechin-3-O-gallate (EGCG), has been demonstrated to contribute to these effects through its anti-oxidative and pro-oxidative properties. Furthermore, several lines of evidence have indicated that the binding affinity of EGCG to specific proteins may explain its mechanism of action. This review article aims to reveal how EGCG-protein interactions can explain the mechanism by which green tea/EGCG can exhibit health beneficial effects. We conducted a literature search, using mainly the PubMed database. The results showed that several methods such as dot assays, affinity gel chromatography, surface plasmon resonance, computational docking analyses, and X-ray crystallography have been used for this purpose. These studies have provided evidence to show how EGCG can fit or occupy the position in or near functional sites and induce a conformational change, including a quaternary conformational change in some cases. Active site blocking, steric hindrance by binding of EGCG near an active site or induced conformational change appeared to cause inhibition of enzymatic activity and other biological activities of proteins, which are related to EGCG’s biological oligomer and formation of their toxic aggregates, leading to the prevention of neurodegenerative diseases and amyloidosis. In conclusion, these studies have provided useful information on the action of green tea/catechins and would lead to future studies that will provide further evidence for rational EGCG therapy and use EGCG as a lead compound for drug design.

DOI： 10.3390/molecules23061295

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：CELL PRESS  

Macrophages play pivotal roles in both the induction and resolution phases of inflammatory processes. Macrophages have been shown to synthesize anti-inflammatory fatty acids in an LXR-dependent manner, but whether the production of these species contributes to the resolution phase of inflammatory responses has not been established. Here, we identify a biphasic program of gene expression that drives production of anti-inflammatory fatty acids 12-24 hr following TLR4 activation and contributes to downregulation of mRNAs encoding pro-inflammatory mediators. Unexpectedly, rather than requiring LXRs, this late program of anti-inflammatory fatty acid biosynthesis is dependent on SREBP1 and results in the uncoupling of NF kappa B binding from gene activation. In contrast to previously identified roles of SREBP1 in promoting production of IL1 beta during the induction phase of inflammation, these studies provide evidence that SREBP1 also contributes to the resolution phase of TLR4-induced gene activation by reprogramming macrophage lipid metabolism.

DOI： 10.1016/j.cmet.2016.11.009

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

Tea derived from the leaves and buds of Camellia sinensis (Theaceae) is consumed worldwide. Green tea contains various components with specific health-promoting effects, and is believed to exert protective effects against diseases including cancer, diabetes and hepatitis, as well as obesity. Of the various tea components, the polyphenol catechins have been the subject of extensive investigation and among the catechins, (-)-epigallocatechin gallate has the strongest bioactivity in most cases. Our research group has postulated that hepatocyte nuclear factor-4α, sterol regulatory element-binding proteins, and tumor necrosis factor-α are targets of green tea constituents including (-)-epigallocatechin gallate for their anti-diabetes, anti-obesity, and anti-hepatitis effects, respectively. Published papers were reviewed to determine whether the observed changes in these factors can be correlated with anti-cancer effects of green tea. Two major action mechanisms of (-)-epigallocatechin gallate have been proposed; one associated with its anti-oxidative properties and the other with its pro-oxidative activity. When reactive oxygen species are assumed to be involved, our findings that (-)-epigallocatechin gallate down- regulated hepatocyte nuclear factor-4α, sterol regulatory element-binding proteins, and tumor necrosis factor-α may explain the anti-cancer effect of green tea as well. However, further studies are required to elucidate which determinant directs (-)-epigallocatechin gallate action as an anti-oxidant or a pro-oxidant for favorable activity.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PUBLIC LIBRARY SCIENCE  

A beta-glucan produced by Aureobasidium pullulans (AP-PG) is consisting of a beta-(1,3)-linked main chain with beta-(1,6)-linked glucose side residues. Various beta-glucans consisting of beta-(1,3)-linked main chain including AP-PG are believed to exhibit anti-tumor activities, and actually, anti-tumor activities of AP-PG in mice have been demonstrated. In this study, we demonstrate that stimulation with AP-PG induces TRAIL expression in mouse and human macrophage-like cell lines. TRAIL is known to be a cytokine which specifically induces apoptosis in transformed cells, but not in untransformed cells. The expression of TRAIL mRNA after stimulation with AP-PG was increased in RAW264.7 cells, Mono Mac 6 cells, and macrophage-differentiated THP-1 cells. The mRNA expression of TNF-alpha and FasL is only weakly increased after stimulation with AP-PG. The induction activity of TRAIL by curdlan, a bacterial beta-glucan, was very similar to that by AP-PG in RAW264.7 cells, but weaker in macrophage-differentiated THP-1 cells. Activation of caspases was found in HeLa cells after treatment with the supernatant of cultured medium from AP-PG-stimulated Mono Mac 6 cells, and was inhibited by the anti-TRAIL neutralizing antibody. These findings suggest that the stimulation with AP-PG effectively induces TRAIL in macrophages, and that it may be related to apoptosis induction of tumor cells.

DOI： 10.1371/journal.pone.0124809

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Authorship：Lead author   Publishing type：Research paper (scientific journal)   Publisher：Baishideng Publishing Group Inc.  

DOI： 10.5493/wjem.v3.i4.100

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE INC  

Pulmonary fibrosis is a devastating condition resulting from excess extracellular matrix deposition that leads to progressive lung destruction and scarring. In the pathogenesis of fibrotic diseases, activation of myofibroblasts by transforming growth factor-beta (TGF-beta) plays a crucial role. Since no effective therapy for pulmonary fibrosis is currently recognized, finding an effective antifibrotic agent is an important objective. One approach might be through identification of agents that inactivate myofibroblasts. In the current study we examined the potential of conditioned medium obtained from several types of cells to exhibit myofibroblast inactivating activity. Conditioned media from lung cancer cell lines A549 and PC9 were found to have this action, as shown by its ability to decrease alpha-smooth muscle actin expression in MRC-5 cells. Subsequently the inhibitory factor was purified from the medium and identified as 5'-deoxy-5'-methylthioadenosine (MTA), and its mechanism of action elucidated. Activation of protein kinase A and cAMP responsive element binding protein (CREB) were detected. MTA inhibited TGF-beta-induced mitogen-activated protein kinase activation. Furthermore, the gain-of-function mutant CREB caused inactivation of myofibroblasts. These results show that A549 and PC9 conditioned media have the ability to inactivate myofibroblasts, and that CREB-phosphorylation plays a central role in this process. (C) 2011 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.abb.2011.12.012

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS LTD  

Heparanase. the enzyme that degrades heparan sulfate, has been implicated to play important and characteristic roles ill organogenesis. tissue organization. cell mi,ration. and tumor metastasis. Clarification of its expression. its intracellular sorting,, and its secretion is. therefore. of Much importance to Understand its role ill cell biology. In addition to the 1.7 Kb transcript previously reported. we detected a 1.5 Kb transcript of human heparanase by RT-PCR. The smaller transcript was as shown to be ill alternatively spliced variant lacking exon 5, which contains the essential glutamic acid residue required tor enzyme activity. When expressed in COS-7 cells this variant did not show any heparanase activity. Full-length heparanase and the exon 5-deleted splice variant were expressed in COS-7 cells and examined by confocal laser scanning microscopy. Both proteins co-localized with calnexin. a marker protein for the endoplasmic reticulum and they co-immunoprecipitated with calnexin. Both proteins were postulated to be precursors based upon the results of SDS-PAGE analyses. Treatment with endoglycosidases revealed that all potential N-glycosylation sites in the proteins were glycosylated. Tunicamycin treatment of transfected COS-7 cells inhibited N-glycosylation hut did not change the subcellular localization. These results indicate that overexpressed heparanase and its splice variant localize to the endoplasmic reticulum independent of glycosylation in COS-7 cells. Copyright (c) 2008 John Wiley & Sons, Ltd.

DOI： 10.1002/cbf.1492

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：LIPPINCOTT WILLIAMS & WILKINS  

Animal serum used for tissue engineering approaches has unacceptable risk for contamination with infectious agents. In this study, a cytokine-rich autologous serum (CRAS) system was developed. Canine auricular chondrocytes were cultured in medium supplemented with either fetal bovine serum (FBS) or autologous canine serum, alone or supplemented with basic fibroblast growth factor (b-FGF). Cell proliferative capacity was higher in the CRAS cultures than in those cultured in FBS, with greater expression of aggrecan and type II collagen in the b-FGF-supplemented CRAS group. The chondrocytes were seeded onto an ear-shaped biodegradable polymer (poly-L-lactide:E-caprolactone, 50:50) and cultured in a Bioflow reactor for 1 week, using the 3 different culture media indicated above, and subsequently implanted into nude mice. The best outcome (cartilage gene expression and morphologic properties) was seen with tissue-engineered constructs precultured in the b-FGF-supplemented CRAS media. These findings indicate a clinically realizable approach for tissue engineering of cartilaginous structures.

DOI： 10.1097/SAP.0b013e31814b2cb5

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER  

Myofibroblasts are metabolically and morphologically distinctive fibroblasts expressing alpha-smooth muscle actin (alpha-SMA), and their activation plays a key role in development of the fibrotic response. In an activated state, myofibroblasts cease to proliferate and start to synthesize large amounts of extracellular component proteins. The expression of alpha-SMA correlates with the activation of myofibroblasts. Decorin, a member of the small leucine-rich proteoglycan gene family, has been implicated in the negative control of cell proliferation primarily by upregulating the expression of p21, a potent inhibitor of cyclin-dependent kinase. In order to examine the effect of decorin on myofibroblast cell growth, we rendered a human lung myofibroblast cell line, MRC-5, quiescent by either cell-cell contact or serum starvation, and examined the relationship between decorin and alpha-SMA expression in these cells. The expression of decorin in cells made quiescent by serum starvation was lower than that in cells made quiescent by cell-cell contact. In contrast, the expression of alpha-SMA in cells made quiescent by cell-cell contact was lower than that in cells made quiescent by serum starvation. Furthermore, forced expression of decorin was accompanied by a suppression of alpha-SMA expression, whereas knocking down of decorin expression by RNA interference increased the expression of alpha-SMA.

DOI： 10.1007/s11010-007-9629-9

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When the tumour suppressor p53 is activated by DNA damage, it stimulates the transcription of its target genes, which then induce cell cycle arrest or apoptosis. Here, we examined the role p53 plays in the antitumour effect of combination treatment with pegylated interferon (PEG-IFN)-α and 5-fluorouracil (5-FU), which has been shown to effectively treat advanced hepatocellular carcinoma (HCC). Nude mice were injected subcutaneously with cultured HepG2 cells, in which p53 is functional. They were treated a week later with PEG-IFN and/or 5-FU for 7 weeks, after which we measured and examined their tumours. Combination groups showed significantly lower tumour volumes and higher tumour cell apoptosis than the other groups. Combination treatment and PEG-IFN monotherapy also significantly elevated the p53 protein and mRNA levels in the tumour but only combination treatment increased the degree of p53 phosphorylation at serine46 and induced p53-regulated apoptosis-inducing protein 1 (p53AIP1) expression. The antitumour effects of combination treatment is due in part to the elevation by PEG-IFN of p53 protein and mRNA expression and in part to the DNA damage that is generated by 5-FU, which induces p53 serine46 phosphorylation, which in turn upregulates p53AIP1 expression. © 2007 Cancer Research.

DOI： 10.1038/sj.bjc.6604058

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ACADEMIC PRESS INC ELSEVIER SCIENCE  

It has been reported that vascular endothelial growth factor (VEGF) and its receptors play an important role in the destruction of articular cartilage in ostcoarthritis through increased production of matrix metalloproteinases. We investigated whether the oxidized low-density lipoprotein (ox-LDL) binding to lectin-like ox-LDL receptor-1 (LOX-1) upregulates VEGF expression in cultured bovine articular chondrocytes (BACs). Ox-LDL markedly increased VEGF mRNA expression and protein release in time- and dose-dependent manners, which was significantly suppressed by anti-LOX-1 antibody pretreatment. Activation of peroxisome proliferator-activated receptor (PPAR)-gamma was evident in BACs with ox-LDL addition and was attenuated by anti-LOX-1 antibody. The specific PPAR-gamma inhibitor GW9662 suppressed ox-LDL-induced VEGF expression. These results suggest that the ox-LDL/LOX-1 system upregulates VEGF expression in articular cartilage, at least in part, through activation of PPAR-gamma and supports the hypothesis that ox-LDL is involved in cartilage degradation via LOX-1. (c) 2006 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.bbrc.2006.07.133

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：BIOMEDICAL RESEARCH PRESS LTD  

Using a DNA microarray, we analyzed about 16,600 genes for changes in expression associated with the differentiation of human promyelocytic leukemia HL-60 cells induced by 1 alpha,25-dihydroxyvitamin D-3 (DVD). Many of the up-regulated genes could be correlated to differentiation-associated changes toward a monocyte/macrophage lineage, and many down-regulated genes could be correlated to repressed cell growth. The present study revealed the down-regulated gene expression of importins and exportins 1, 5, 7, and exportin-tRNA. Thus, the present results confirmed our previous findings of down-regulation of exportin 1and exportin-tRNA by DVD. Gene expression of exportin 6 is suggested to be regulated differently from that of exportins 1, 5, 7, and exportin-tRNA. The down-regulation of nuclear transport factors may be deeply associated with the differentiation of HL-60 cells induced by DVD.

DOI： 10.2220/biomedres.27.99

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：BIOMEDICAL RESEARCH PRESS LTD  

The active form of vitamin D-3, 1 alpha,25-dihydroxyvitamin D-3 (DVD), is a potent inducer of cell differentiation and inhibits proliferation of cells such as human promyelocytic leukemia HL-60 cells. In the present study, we examined the effects of DVD on the expression of exportin-1 and exportin-1, which play essential roles in the transport of mRNA and tRNA, respectively. The results of reverse transcription-polymerase chain reaction and quantitative real-time polymerase chain reaction indicated that DVD down-regulated the gene expression of these exportins. Western blotting revealed the decreased production of these proteins in DVD-treated cells. Thus, the present findings of decreased expression of exportin-1 and exportin-t induced by DVD can be correlated to inhibition of the proliferation of HL-60 cells.

DOI： 10.2220/biomedres.27.89

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：BIRKHAUSER VERLAG AG  

Objective: Articular cartilage is an avascular tissue in which chondrocytes are exposed to hypoxic conditions. We previously demonstrated that reactive oxygen species (ROS) induced apoptosis of chondrocytes. We also demonstrated that nitric oxide (NO) was induced when chondrocytes were exposed to hypoxia and that NO inhibited the ROS-induced apoptosis. Hyaluronan (HA) is a high molecular weight glycosaminoglycan whose antioxidative effects have been reported. The purpose of the present study was to determine whether HA synthesis was induced in chondrocytes exposed to hypoxia, and, if so, whether the hypoxia-induced HA synthesis is regulated by NO.
Methods: Bovine articular chondrocytes were used in this study. Levels of HA were determined by the sandwich enzyme-binding assay. Expression of HA synthase (HAS) was determined with reverse transcription-polymerase chain reaction. The production of NO was examined using the Griess reaction. We also determined inducible nitric oxide synthase (iNOS) enzyme synthesis using the histochemistry and Western blot analysis.
Results: Chondrocytes cultured under hypoxic conditions exhibited enhanced HA synthesis. When the NO inhibitors, L-NMMA and L-NAME, were added, the hypoxia-enhanced HA levels in the culture medium were significantly inhibited.
Conclusions: Endogenous NO synthesis plays an important role in hypoxia-enhanced HA synthesis.

DOI： 10.1007/s00011-005-0012-6

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JAPAN SOC CELL BIOLOGY  

The physiologically active metabolite of vitamin D-3, 1 alpha,25-dihydroxyvitamin D-3 (DVD), is a potent inducer of cell differentiation in human myeloid leukemia cells. In the present study, we examined changes in gene expression during DVD-induced cell differentiation of promyelocytic HL-60 cells employing a DNA microarray technique. The results identified 7 up-regulated and 9 down-regulated genes with a change greater than 1.5-fold after the DVD-treatment for both 2 and 6 days. Seven of these genes were further examined by reverse transcription-polymerase chain reaction (RT-PCR). The results showed that findings obtained from the DNA microarray analysis and RT-PCR are generally comparable with each other. Gene expression of the subunits of eukaryotic translation initiation factor 2 was then examined by methods including RT-PCR and real-time PCR. The results indicated the suppression of these genes, suggesting a linkage to differentiation-associated growth inhibition of these cells.

DOI： 10.1247/csf.30.1

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-LISS  

Basic fibroblast growth factor (b-FGF) may have a role in tissue-engineered chondrogenesis. However, when applied in solution, b-FGF rapidly diffuses from the implant site. In another approach for tissue engineering, poly-lactide-based copolymers have shown promise as scaffolds for chondrocytes used to tissue engineer auricular cartilage in the shape of an ear. This study evaluated the effectiveness of b-FGF impregnated in gelatin microspheres to achieve slow growth factor release for augmenting the in vivo chondrogenic response. Whereas I-125-labeled b-FGF injected in solution showed rapid in vivo clearance from the injection site (only 3% residual after 24 h), when incorporated into gelatin microspheres, 44% and 18% of the b-FGF remained at 3 and 14 days, respectively. Canine chondrocytes were isolated and grown in vitro onto ear-shaped poly-lactide/caprolactone copolymers for I week, then implanted into the dorsal subcutaneous tissue of nude mice; implants contained bFGF either in free solution or in gelatin microspheres. A third group underwent preinjection of b-FGF in gelatin microspheres 4 days before chondrocyte-copolymer implantation. The implants with b-FGF-incorporated microspheres showed the greatest chondrogenic characteristics at 5 and 10 weeks postoperatively: good shape and biomechanical trait retention, strong (histologic) metachromasia, rich vascularization of surrounding tissues, and increased gene expression for type II collagen (cartilage marker) and factor VIII-related antigen (vascular marker). In the case of implant site preadministration with b-FGF-impregnated microspheres, the implant architecture was not maintained as well, and reduced vascularization and metachromasia was also apparent. In conclusion, these findings indicate that a sustained release of b-FGF augments neovascularization and chondrogenesis in a tissue-engineered cartilage construct. (c) 2005 Wiley Periodicals, Inc.

DOI： 10.1002/jbm.a.30343

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Tea and tea constituents are known to induce apoptosis in a variety of cancerous cells, suggesting their beneficial effects as chemopreventive agents. Previous studies have shown that low molecular weight constituent catechins and high molecular weight fractions of tea have the apoptosis-inducing activity, but that their action mechanisms may be different. Since cell cycle arrest is known to be one of the underlying mechanisms of apoptosis, we examined the effects of these tea constituents on cell cycle progression of human leukemia U937 cells. The results showed that the high molecular weight fractions of green tea and black tea caused G2/M arrest associated with up-regulation of p21/Waf1, but that epigallocatechin gallate, a major component of green tea catechins, gave little effects of cell cycle progression and p21/Waf1 expression. Thus, the present results suggest the difference in the apoptosis-induction mechanism between the two types of tea constituents.

DOI： 10.2220/biomedres.26.1

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JAPANESE BIOCHEMICAL SOC  

5-Aminolevulinate synthase (ALAS) is a mitochondrial enzyme that catalyzes the first step of the heme biosynthetic pathway. The mitochondrial import, as well as the synthesis, of the nonspecific isoform of ALAS (ALAS1) is regulated by heme through a feedback mechanism. A short amino acid sequence, the heme regulatory motif (HRM), is known to be involved in the regulatory function of heme. To determine the role of the HRM in the heme-regulated transport of the nonspecific and erythroid forms of ALAS in vivo, we constructed a series of mutants of rat ALAS1, in which the cysteine residues in the three putative HRMs in the N-terminal region of the enzyme were converted to serine ones by site-directed mutagenesis. The wild-type and mutant enzymes were expressed in quail QT6 fibroblasts through transient transfection, and the mitochondrial import of these enzymes was examined in the presence of hemin. Hemin inhibited the mitochondrial import of wild-type ALAS1, but this inhibition was reversed on the mutation of all three HRMs in the enzyme, indicating that the HRMs are essential for the heme-mediated inhibition of ALAS1 transport in the cell. By contrast, exogenous hemin did not affect the mitochondrial import of the erythroid-specific ALAS isoform (AIAS2) under the same experimental conditions. These results may reflect the difference in the physiological functions of the two ALAS isoforms.

DOI： 10.1093/jb/mvh112

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：W B SAUNDERS CO LTD  

Objective: To examine the effect of oxidized low-density lipoprotein (ox-LDL) on the intracellular production of reactive oxygen species (ROS) in bovine articular chondrocytes (BACs) and to investigate whether this increase occurs through binding to the receptor lectin-like ox-LDL receptor-1 (LOX-1). Furthermore, to ascertain whether the binding of ox-LDL to LOX-1 results in NF-kappaB activation.
Design: BACs were preincubated with 2',7'-dichlorofluorescin diacetate (DCFH-DA), a dye that allows the monitoring of intracellular ROS production for DCF by spectrofluorometry. BACs were incubated with native LDL and ox-LDL (10, 50, and 100 mug/ml) for 5 min at 37degreesC and DCF formation was observed. BACs were also preincubated with anti-LOX-1 mAb (40 mug/ml) or ascorbic acid (10 t!V!). Nuclear extracts from BACs treated for the indicated periods with 50 mug/ml ox-LDL, and preincubated with anti-LOX-1 mAb or ascorbic acid, were prepared and analyzed by electrophoretic mobility shift assay (EMSA).
Results: ox-LDL induced a significant dose-dependent increase in ROS production after 5-min incubation with BACs (P<0.001). ROS formation was markedly reduced in BACs preincubated with anti-LOX-1 mAb and ascorbic acid (P<0.001). Activation in BACs of the transcription factor NF-κB was evident after 5-min incubation with ox-LDL and was attenuated by anti-LOX-1 mAb and ascorbic acid.
Conclusion: ox-LDL binding to LOX-1 in BACs increased the production of intracellular ROS and activated NF-κB. Reduction of NF-κB activation by ascorbic acid indicates that the activation, at least in part, is ROS-dependent. These observations support the hypothesis that hypercholesterolemia is one of several risk factors for arthritis, and that lipid peroxidation products such as ox-LDL are involved in cartilage matrix degradation. © 2004 OsteoArthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.joca.2004.04.005

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

The ethanol extract from Japanese horseradish wasabi was found to inhibit cell proliferation in human monoblastic leukemia U937 cells by inducing apoptotic cell death. Separation by methods including silica gel chromatography and preparative HPLC gave an active compound, which was identified as 6-methylsulfinylhexyl isothiocyanate (6-HITC). Several lines of evidence indicated that 6-HITC induced apoptosis in U937 cells and human stomach cancer MKN45 cells. Thus, 6-HITC is potentially useful as a natural anti-cancer agent. (C) 2003 Elsevier Science Ltd. All rights reserved.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

High molecular weight tea fractions TNDs (tea non-dialysates) were found to induce apoptosis in mouse JB6 cells, human leukemia U937 cells, stomach cancer MKN-45 cells, and colon cancer WiDr cells. Black tea non-dialysate caused the decrease in the expression of mRNAs for caspase I and TNF-alpha and the increase in mRNA expression for several cell surface proteins related to apoptosis in U937 cells. Peroral administration of green tea non-dialyzate (0.05% in water) resulted in the decrease in the polyp number in the stomach and colon of APC knockout mice and the increase in the apoptosis index in the small tumors. These data suggest that drinking of tea is beneficial for prevention of cancer of the digestive tract on the basis of apoptosis-inducing activities of its constituents.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS LTD  

A 15-kDa lectin was isolated from the edible mushroom Kurokawa by affinity chromatography using N,N'-diacetylehitobiose-Sepharose 4B. The results of microsequencing analysis indicated that the lectin has a partial amino acid sequence similar to the mushroom lectin, Agaricus bisporus agglutinin (ABA). We found that the Kurokawa lectin inhibited proliferation of human monoblastic leukemia U937 cells dose-dependently. Several lines of evidence indicated that this inhibition was due to its apoptosis induction. We observed that the lectin induced apoptotic bodies formation, chromatin condensation, and DNA ladder formation, features of apoptosis. The DNA ladder formation was inhibited by a general inhibitor of caspases, which are known to play essential roles in apoptosis. In contrast. ABA did not have cell growth-inhibiting or apoptosis-inducing activities. Thus, the Kurokawa lectin is the first mushroom lectin with apoptosis-inducing activity.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JAPANESE BIOCHEMICAL SOC  

Effects of rice bran agglutinin (RBA) on human monoblastic leukemia U937 cells were examined in comparison with those of wheat germ agglutinin (WGA) and Viscum album agglutinin (VAA). These lectins inhibit cell growth, and several lines of evidence indicate that the growth inhibition is caused by the induction of apoptosis. We observed that RBA induces chromatin condensation, externalization of membrane phosphatidylserine, and DNA ladder formation, features of apoptosis. DNA ladder formation was inhibited by a general inhibitor against caspases, which are known to play essential roles in apoptosis. Flow cytometric analysis revealed that RBA and WGA cause G2/M phase cell cycle arrest with increased expression of Waf1/p2l, while cell cycle arrest was not observed for VAA. These data indicate that RBA induces apoptosis associated with cell cycle arrest in U937 cells, and suggest that the induction mechanism for RBA is similar to that for WGA, but different from that for VAA.

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Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS LTD  

High molecular weight fractions of green tea, black tea, oolong tea, and pu-erh tea were found to induce apoptosis in human monoblastic leukemia U937 cells by examination of their ability to inhibit cell proliferation and to induce apoptotic body formation and DNA ladder formation. These tea fractions were also shown to induce apoptosis in stomach cancer MKN-45 cells. In addition to known antitumor-promoting activity of tea high molecular weight fractions, their apoptosis-inducing activity may contribute to canter chemopreventive effects of tea.

DOI： 10.1271/bbb.65.459

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PubMed

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：GEORG THIEME VERLAG KG  

Three galloyl monosaccharides contained in medicinal plants were examined for apoptosis-inducing activity in human histiocytic lymphoma U937 cells. Tetragalloyl glucose (TgG) induced apoptosis as found by chromatin condensation, DNA ladder formation, and inhibition by a caspase inhibitor. Digalloyl hamamelose had moderate activity, while monogalloyl glucose was only marginally active. These findings suggest that the number and disposition of their phenolic groups are important for apoptosis induction. TgG induced apoptosis in human colon and stomach cancer cell lines as well, indicating it is potentially useful as an anti-cancer agent.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Several catechin compounds were examined for their ability to induce apoptosis in human hystiocytic lymphoma U937 cells. Catechins with a pyrogallol-type structure in a B-ring induced apoptosis and a 3-O-gallate group in cis-relationship to the B ring enhanced the activity. Catechins without a pyrogallol-type structure in a molecule lacked activity. These data suggest the important role of the 5'(3')-hydroxyl group in the B-ring and that a pyrogallol-type structure in a molecule is a minimum requirement for apoptosis induction by catechin compounds. (C) 2000 Elsevier Science Ltd. All rights reserved.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IOS PRESS  

Epigallocatechin gallate (EGCg) and theaflavins, a major constituent of green tea infusion and the constituents of black tea, respectively, were found to inhibit matrix metalloproteinases (MMPs) which are intimately associated with tumor invasion and metastasis. EGCg and related polyphenols exhibited apoptosis-inducing activity for several cancer cell lines including human stomach and colon cancer cells. Comparison of the activity of these compounds revealed the importance of the number and the steric disposition of hydroxyl groups. A pyrogallol-type structure in a molecule is a minimum requirement for apoptosis induction of catechin compounds and that in the B ring has an important role in the activity. These data would provide useful information for designing anti-cancer agents on the basis of anti-inhibitory activity for MMPs and/or apoptosis-inducing activity.

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Authorship：Lead author   Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media)  

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Event date： 2024.9

Language：Japanese   Presentation type：Poster presentation  

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Event date： 2024.5

Presentation type：Oral presentation (general)  

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Event date： 2023.7

Language：Japanese   Presentation type：Poster presentation  

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Event date： 2023.3

Language：Japanese   Presentation type：Poster presentation  

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Event date： 2022.6

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