67 research outputs found
Cartoons and collaboration in wartime China: the mobilization of Chinese cartoonists under Japanese occupation
The work of Chinese cartoonists who published their illustrations in the popular press in occupied China from 1937 to 1945 has largely escaped the attention of scholars of both the occupation itself and the broader field of cartoon history. This article seeks to fill this gap in the literature by analyzing how the very nature of the occupation, together with efforts undertaken by collaborationist governments such as that of Wang Jingwei, created a context in which a particular body of artists could continue to draw. In so doing, the article raises questions about the place of “collaborationist” cartoonists in the broader development of art and propaganda in China and about the very nature of collaboration in the Chinese context
Leaf Extract of Eupatorium adenophorum negatively Regulates Growth of Alternanthera philoxeroides
Allelopathy is an important biological phenomenon in exotic plant invasions. Studies about this phenomenon can help us to understand how plant interactions influence plant colony and ecosystem functioning. Both alligator weed (Alternanthera philoxeroides, Ap) and crofton weed (Eupatorium adenophorum, Ea) are important destructive exotic species in China. Their allelopathic effects on native plant species are well documented. However, whether alligator weed and crofton weed antagonize each other regarding plant growth? There is largely unknown currently. Here we report that the leaf extract from crofton weed possesses the negative effect on the growth of alligator weed. The results showed that root growth of alligator weed could be seriously inhibited by aqueous extract from crofton weed, exhibited as no root or a few roots if only. Consistent with the inhibition of root growth, we observed changes of physiological and biochemical parameters in treated alligator weed. The chlorophyll content, the root activity and the acetolactate synthase (ALS) activity were significantly decreased; while the rate of superoxide anion (O2-), the malondialdehyde (MDA) content, the peroxidase (POD) activity, and the shikimic acid content were remarkably increased in the treated alligator weed plants. These physiological analyzes suggested that the main allelopathic effects of crofton weed were mainly through affecting the integrity of cell membrane and the activity of the key enzymes. Further, these data also imply that one exotic species has the potential value to be used in bio-control of the other exotic species
Transplanted adult human hepatic stem/progenitor cells prevent histogenesis of advanced hepatic fibrosis in mice induced by carbon tetrachloride
Transplantation of adult human hepatic stem/progenitor cells (hHSPCs) has been considered as an alternative therapy, replacing donor liver transplantation to treat liver cirrhosis. This study assessed the antifibrotic effects of hHSPCs in mice with fibrosis induced by carbon tetrachloride (CCl4) and examined the actions of hHSPCs on the fibrogenic activity of human hepatic stellate cells (HSCs) in a coculture system. Isolated hHSPCs expressed stem/progenitor cell phenotypic markers. Mice were given CCl4 (twice weekly for 7 weeks) and hHSPC transplantation weekly. CCl4 induced advanced fibrosis (bridging fibrosis and cirrhosis) in mice, which was prevented by hHSPC transplantation. The liver of hHSPC-transplanted mice showed only occasional short septa and focal parenchymal fibrosis, and a 50% reduction in hepatic collagen, assessed by Sirius red stain histomorphometry. Moreover, the proteins for α-smooth muscle actin (α-SMA) and collagen I were decreased. While α-SMA, collagen α1(I), and tissue inhibitor of metalloproproteinase-1 mRNAs were decreased, matrix metalloproteinase (MMP)-1 mRNA was increased, consistent with decreased fibrogenesis. MMP-2 and transforming growth factor-β were not affected. Alanine aminotransferase and aspartate aminotransferase were lower, suggesting improvement of liver function/damage. In coculture, hHSPCs elicited changes of α-SMA and fibrogenic molecules in HSCs similar to those observed in vivo, providing evidence for a functional link between hHSPCs and HSCs. A decreased HSC proliferation was noted. Thus, transplantation of hHSPCs prevents histogenesis of advanced liver fibrosis caused by CCl4. hHSPCs mediate downregulation of HSC activation coincident with modulation of fibrogenic molecule expression, leading to suppression of fibrogenesis both in vivo and in vitro
Inflammatory-mediated repression of the rat ileal sodium-dependent bile acid transporter by c-fos nuclear translocation
AbstractBackground & Aims: Ileal malabsorption of bile salts is observed in Crohn's ileitis. We define the transcriptional mechanisms involved in cytokine-mediated repression of the rat apical sodium-dependent bile acid transporter (ASBT). Methods: ASBT regulation was studied in IL-1β–treated IEC-6 and Caco-2 cells and in indomethacin-treated rats. Results: Indomethacin-induced ileitis in Lewis rats leads to specific reductions in ileal ASBT messenger RNA and protein levels, whereas c-jun and c-fos are induced. The proinflammatory cytokines interleukin-1β and tumor necrosis factor repress the activity of the ASBT promoter in Caco-2 and intestinal epithelial cell-6 cells. This effect is blocked by the proteasome inhibitor, MG-132, or by the phosphatidyl inositol 3-kinase inhibitor, wortmannin. Indomethacin (in vivo) or proinflammatory cytokine (in vitro) treatment leads to serine phosphorylation and nuclear translocation of c-fos. Mutation of a 5' activated protein (AP)-1 site inactivates the ASBT promoter, whereas mutation of the 3' site abrogates the proinflammatory cytokine–mediated repression. The 5' site binds a c-jun homodimer, whereas the 3' site binds a c-jun/c-fos heterodimer. c-Jun overexpression enhances ASBT promoter activity, whereas a dominant negative c-jun construct inactivates the promoter. c-Fos overexpression represses promoter activity. A 27 base pair cis-element from the 3' site in the ASBT promoter imparts cytokine-mediated down-regulation to a heterologous SV40 promoter construct. Conclusions: The ASBT promoter contains 2 distinct cis AP-1 elements; the 5' element binds homodimeric c-jun and mediates basal transcription. Inflammation is associated with up-regulation, phosphorylation, and nuclear translocation of c-fos, which then represses ASBT promoter activity via binding of the 3' AP-1 element by a c-fos/c-jun heterodimer.GASTROENTEROLOGY 2002;123:2005-201
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Transcription factor IRF8 directs a silencing programme for TH17 cell differentiation
TH17 cells are recognized as a unique subset of T helper cells that have critical roles in the pathogenesis of autoimmunity and tissue inflammation. Although RORγt is necessary for the generation of TH17 cells, the molecular mechanisms underlying the functional diversity of TH17 cells are not fully understood. Here we show that a member of interferon regulatory factor (IRF) family of transcription factors, IRF8, has a critical role in silencing TH17-cell differentiation. Mice with a conventional knockout, as well as a T cell-specific deletion, of the Irf8 gene exhibited more efficient TH17 cells. Indeed, studies of an experimental model of colitis showed that IRF8 deficiency resulted in more severe inflammation with an enhanced TH17 phenotype. IRF8 was induced steadily and inhibited TH17-cell differentiation during TH17 lineage commitment at least in part through its physical interaction with RORγt. These findings define IRF8 as a novel intrinsic transcriptional inhibitor of TH17-cell differentiation
5-Fluorouracil targets thymidylate synthase in the selective suppression of TH17 cell differentiation
While it is well established that treatment of cancer patients with 5-Fluorouracil (5-FU) can result in immune suppression, the exact function of 5-FU in the modulation of immune cells has not been fully established. We found that low dose 5-FU selectively suppresses TH17 and TH1 cell differentiation without apparent effect on Treg, TH2, and significantly suppresses thymidylate synthase (TS) expression in TH17 and TH1 cells but has a lesser effect in tumor cells and macrophages. Interestingly, the basal expression of TS varies significantly between T helper phenotypes and knockdown of TS significantly impairs TH17 and TH1 cell differentiation without affecting the differentiation of either Treg or TH2 cells. Finally, low dose 5-FU is effective in ameliorating colitis development by suppressing TH17 and TH1 cell development in a T cell transfer colitis model. Taken together, the results highlight the importance of the anti-inflammatory functions of low dose 5-FU by selectively suppressing TH17 and TH1 immune responses
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T cell–derived inducible nitric oxide synthase switches off TH17 cell differentiation
RORγt is necessary for the generation of TH17 cells but the molecular mechanisms for the regulation of TH17 cells are still not fully understood. We show that activation of CD4+ T cells results in the expression of inducible nitric oxide synthase (iNOS). iNOS-deficient mice displayed enhanced TH17 cell differentiation but without major effects on either TH1 or TH2 cell lineages, whereas endothelial NOS (eNOS) or neuronal NOS (nNOS) mutant mice showed comparable TH17 cell differentiation compared with wild-type control mice. The addition of N6-(1-iminoethyl)-l-lysine dihydrochloride (L-NIL), the iNOS inhibitor, significantly enhanced TH17 cell differentiation, and S-nitroso-N-acetylpenicillamine (SNAP), the NO donor, dose-dependently reduced the percentage of IL-17–producing CD4+ T cells. NO mediates nitration of tyrosine residues in RORγt, leading to the suppression of RORγt-induced IL-17 promoter activation, indicating that NO regulates IL-17 expression at the transcriptional level. Finally, studies of an experimental model of colitis showed that iNOS deficiency results in more severe inflammation with an enhanced TH17 phenotype. These results suggest that NO derived from iNOS in activated T cells plays a negative role in the regulation of TH17 cell differentiation and highlight the importance of intrinsic programs for the control of TH17 immune responses
Моделирование формирования структуры металломатричных композитов в процессе синтеза с оценкой эффективных свойств
Работа посвящена моделированию процесса кристаллизации композита с металлической матрицей и твердыми включениями с учетом условий синтеза (давление, скорость охлаждения), моделированию процесса формирования переходной зоны между частицами и матрицей и расчету эффективных свойств получаемых композитов.The work is devoted to modeling the crystallization process of metal matrix composite with solid inclusions, taking into account the synthesis conditions (pressure, cooling rate), to modeling the formation of the transition zone between particles and matrix, and calculating the effective properties of the resulting composites
Distinct Roles of Brd2 and Brd4 in Potentiating the Transcriptional Program for Th17 Cell Differentiation
The BET proteins are major transcriptional regulators and have emerged as new drug targets, but their functional distinction has remained elusive. In this study, we report that the BET family members Brd2 and Brd4 exert distinct genomic functions at genes whose transcription they co-regulate during mouse T-helper 17 (Th17) cell differentiation. Brd2 is associated with the chromatin insulator CTCF and the cohesin complex to support cis-regulatory enhancer assembly for gene transcriptional activation. In this context, Brd2 binds the transcription factor Stat3 in an acetylation-sensitive manner and facilitates Stat3 recruitment to active enhancers occupied with transcription factors Irf4 and Batf. In parallel, Brd4 temporally controls RNA polymerase II (Pol II) processivity during transcription elongation through cyclinT1/Cdk9 recruitment and Pol II Ser2 phosphorylation. Collectively, our study uncovers both separate and interdependent Brd2 and Brd4 functions in potentiating the genetic program required for Th17 cell development and adaptive immunity.,
, Cheung et al. uncover both separate and interdependent Brd2 and Brd4 genomic functions in potentiating the genetic program required for Th17 cell development and adaptive immunity. Brd2 interacts with transcription factor Stat3 and chromatin insulator CTCF/cohesin complex to support enhancer assembly, whereas Brd4 temporally controls RNA PolII for transcription elongation
Transplanted adult human hepatic stem/progenitor cells prevent histogenesis of advanced hepatic fibrosis in mice induced by carbon tetrachloride
Transplantation of adult human hepatic stem/progenitor cells (hHSPCs) has been considered as an alternative therapy, replacing donor liver transplantation to treat liver cirrhosis. This study assessed the antifibrotic effects of hHSPCs in mice with fibrosis induced by carbon tetrachloride (CCI4) and examined the actions of hHSPCs on the fibrogenic activity of human hepatic stellate cells (HSCs) in a coculture system. Isolated hHSPCs expressed stem/progenitor cell phenotypic markers. Mice were given CCl4 (twice weekly for 7 weeks) and hHSPC transplantation weekly. CCl4 induced advanced fibrosis (bridging fibrosis and cirrhosis) in mice, which was prevented by hHSPC transplantation. The liver of hHSPC-transplanted mice showed only occasional short septa and focal parenchymal fibrosis, and a 50% reduction in hepatic collagen, assessed by Sirius red stain histomorphometry. Moreover, the proteins for a-smooth muscle actin (alpha-SMA) and collagen I were decreased. While alpha-SMA, collagen alpha 1(I), and tissue inhibitor of metalloproproteinase-1 mRNAs were decreased, matrix metalloproteinase (MMP)-1 mRNA was increased, consistent with decreased fibrogenesis. MMP-2 and transforming growth factor-beta were not affected. Alanine aminotransferase and aspartate aminotransferase were lower, suggesting improvement of liver function/damage. In coculture, hHSPCs elicited changes of alpha-SMA and fibrogenic molecules in HSCs similar to those observed in vivo, providing evidence for a functional link between hHSPCs and HSCs. A decreased HSC proliferation was noted. Thus, transplantation of hHSPCs prevents histogenesis of advanced liver fibrosis caused by CCl4. hHSPCs mediate down-regulation of HSC activation coincident with modulation of fibrogenic molecule expression, leading to suppression of fibrogenesis both in vivo and in vitro
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