The ab initio generalized gradient approximation (GGA)+U study of multiferroic (La Bi )<sub>2</sub>FeCrO<sub>6</sub> in pnma structure and ferri-magnetic order, including Hubbard corrections ( ...The ab initio generalized gradient approximation (GGA)+U study of multiferroic (La Bi )<sub>2</sub>FeCrO<sub>6</sub> in pnma structure and ferri-magnetic order, including Hubbard corrections ( eV) for transition metal/rare earth d-electrons with 20 atoms cell, shows optimum local magnetic moments of (Cr , Fe equal to (?2.56, 4.14) μB and an ideal spin-down band gap of 1.54 eV. Tuned-band gap La-substituted double oxide perovskites BFCO should exhibit enhanced visible-light absorption and carrier mobility, thus could be convenient light absorbers and then efficient alternatives to wide-gap chalcopyrite absorber-based solar cells failing to achieve highest power conversion efficiencies, and even compete with their metal-organic halide perovskites counterparts.展开更多
We have studied the expression of a subset of genes encoding important tumor growth related factors in U87 glioma cells with IRE1 (inositol requiring enzyme-1) knockdown as well as their hypoxic regulation. It was sho...We have studied the expression of a subset of genes encoding important tumor growth related factors in U87 glioma cells with IRE1 (inositol requiring enzyme-1) knockdown as well as their hypoxic regulation. It was shown that the expression levels of activating transcription factor 6 (ATF6), clusterin (CLU), adhesion G protein-coupled receptor E5 (ADGRE5), transglutaminase?2, C polypeptide (TGM2), leukemia inhibitory factor (LIF), phosphoserine aminotransferase 1 (PSAT1), glyoxalase I (GLO1) and tetraspanin 13 (TSPAN13) are significantly down-regulated in glioma cells with the knockdown of IRE1 signaling enzyme. It was also shown that in glioma cells subjected to hypoxia, the expression levels of PSAT1, TSPAN13, EIF2AK3, and TGM2 genes were up-regulated, whereas the expression of ATF6 gene was down-regulated. At the same time, the expression levels of LIF, CLU, and ADGRE5 genes did not change in response to hypoxic treatment.?Furthermore, inhibition of IRE1, a key effector of an unfolded protein response pathway, modified the effect of hypoxia on the expression of most studied genes. Present study demonstrates that IRE1 knockdown down-regulated the expression of most studied genes and modified their hypoxic regulation and that these changes possibly contributed to the suppression of glioma growth in cells without IRE1 signaling enzyme function.展开更多
Background Periostin originally designated osteoblast-specific factor 2 （OSF-2） is frequently found to be highly expressed in various types of human cancer cell lines in vitro and human cancer tissues in vivo. We pr...Background Periostin originally designated osteoblast-specific factor 2 （OSF-2） is frequently found to be highly expressed in various types of human cancer cell lines in vitro and human cancer tissues in vivo. We proposed that periostin was a key factor during the process of proliferation and invasion in cancer cells. We investigated the effect of periostin on the function of human osteosarcoma cell line （U2OS）, such as proliferation, apoptosis, invasion and the associated signal pathway.Methods A human PGCsi/U6 promoter-driven DNA template was adopted to induce short hairpin RNA （shRNA）-triggered RNA interference （RNAi） to block periostin gene expression in the cell line U2OS. U2OS cells were divided into three groups： cells transfected with phosphate buffered saline as control group （the U2OS group）, cells transfected with pGCsi as negative control group （the NC group） and cells transfected with periostin/pGCsi as experimental group （the pGCsi-periostin group）. Then, transfection efficiency of cell was observed under fluorescent microscope. The expressions of periostin and the related genes in cells were detected by reverse transcription polymerase chain reaction and Western Blotting. Cell viability was determined using the methyl-thiazolyl tetrazolium bromide （MTT） quantitative colorimetric assay. The invasion and migration capability of cells were tested by transwell plates with or without extracellular matrix gel. Furthermore, the changes of cell cycle and apoptosis were analyzed by flow cytometry.Results The transfection efficiency of periostin/pGCsi to U2OS cells was about 70%-80%. When compared with the NC group, the levels of mRNA and protein of periostin in the pGCsi-periostin group decreased by 82% （F=564.71, P＜0.001） and 58% （F=341.51, P ＜0.001 ）, respectively. Meantime, the earlier apoptosis value increased by 417 （F=28.69,P ＜0.001）. The percentage of S phase pGCsi-periostin cells decreased by 21% （F=47.00, P ＜0.001）, however, that of G0-G1 phase cells increased by 12% （F=14.50, P ＜0.001）. The capability of migration and invasion reduced by 41%（F=17.79, P ＜0.001） and 72% （F=197.08, P ＜0.001）, respectively. The cell proliferation in the pGCsi-periostin group decreased by 59% and 72% at 48 and 120 hours after transfection, respectively. The mRNA expressions of transforming growth factor-β and vascular endothelial growth factor decreased by 17% （F=73.99, P ＜0.001） and 47% （F=30.25, P ＜0.001）, respectively. A tendency of lower focal adhesion kinase （FAK） was shown in pGCsi-periostin cells but without any statistically significant difference. Otherwise the expression of p-FAK in those cells had markedly decreased by 21%（F=16.81, P＜0.001）.Conclusions RNAi against periostin can effectively down-regulate periostin gene expression. Periostin increases the hyperplasia and invasion of cancer cells. Periostin might be involved in and served as a tumor promoter gene in the pathogenesis of osteosarcoma.展开更多
Severe influenza infections are often associated with the excessive induction of pro-inflammatory cytokines,which is also referred to as"cytokine storms".Several studies have shown that cytokine storms are d...Severe influenza infections are often associated with the excessive induction of pro-inflammatory cytokines,which is also referred to as"cytokine storms".Several studies have shown that cytokine storms are directly associated with influenzainduced fatal acute lung injury and acute respiratory distress syndrome.Due to the narrow administration window,current antiviral therapies are often inadequate.The efforts to use immunomodulatory agents alone or in combination with antiviral agents in the treatment of influenza in animal models have resulted in the achievement of protective effects accompanied with reduced cytokine production.Currently,there are no immunomodulatory drugs for influenza available for clinical use.Animal models,despite being ideal to study the anti-inflammatory responses to influenza virus infection,are very costly and time-consuming.Therefore,there is an urgent need to establish fast and economical screening methods using cellbased models to screen and develop novel immunomodulatory agents.In this study,we screened seven human cell lines and found that the human monocytic cell U937 supports the replication of different subtypes of influenza viruses as well as the production of the important pro-inflammatory cytokines and was selected to develop the cell-based model.The U937 cell model was validated by testing a panel of known antiviral and immunomodulatory agents and screening a drug library consisting of 1280 compounds comprised mostly of FDA-approved drugs.We demonstrated that the U937 cell model is robust and suitable for the high-throughput screening of immunomodulators and antivirals against influenza infection.展开更多
文摘The ab initio generalized gradient approximation (GGA)+U study of multiferroic (La Bi )<sub>2</sub>FeCrO<sub>6</sub> in pnma structure and ferri-magnetic order, including Hubbard corrections ( eV) for transition metal/rare earth d-electrons with 20 atoms cell, shows optimum local magnetic moments of (Cr , Fe equal to (?2.56, 4.14) μB and an ideal spin-down band gap of 1.54 eV. Tuned-band gap La-substituted double oxide perovskites BFCO should exhibit enhanced visible-light absorption and carrier mobility, thus could be convenient light absorbers and then efficient alternatives to wide-gap chalcopyrite absorber-based solar cells failing to achieve highest power conversion efficiencies, and even compete with their metal-organic halide perovskites counterparts.
文摘We have studied the expression of a subset of genes encoding important tumor growth related factors in U87 glioma cells with IRE1 (inositol requiring enzyme-1) knockdown as well as their hypoxic regulation. It was shown that the expression levels of activating transcription factor 6 (ATF6), clusterin (CLU), adhesion G protein-coupled receptor E5 (ADGRE5), transglutaminase?2, C polypeptide (TGM2), leukemia inhibitory factor (LIF), phosphoserine aminotransferase 1 (PSAT1), glyoxalase I (GLO1) and tetraspanin 13 (TSPAN13) are significantly down-regulated in glioma cells with the knockdown of IRE1 signaling enzyme. It was also shown that in glioma cells subjected to hypoxia, the expression levels of PSAT1, TSPAN13, EIF2AK3, and TGM2 genes were up-regulated, whereas the expression of ATF6 gene was down-regulated. At the same time, the expression levels of LIF, CLU, and ADGRE5 genes did not change in response to hypoxic treatment.?Furthermore, inhibition of IRE1, a key effector of an unfolded protein response pathway, modified the effect of hypoxia on the expression of most studied genes. Present study demonstrates that IRE1 knockdown down-regulated the expression of most studied genes and modified their hypoxic regulation and that these changes possibly contributed to the suppression of glioma growth in cells without IRE1 signaling enzyme function.
基金This study was supported by a grant from the National Natural Science Foundation of China （No. 0973126）.
文摘Background Periostin originally designated osteoblast-specific factor 2 （OSF-2） is frequently found to be highly expressed in various types of human cancer cell lines in vitro and human cancer tissues in vivo. We proposed that periostin was a key factor during the process of proliferation and invasion in cancer cells. We investigated the effect of periostin on the function of human osteosarcoma cell line （U2OS）, such as proliferation, apoptosis, invasion and the associated signal pathway.Methods A human PGCsi/U6 promoter-driven DNA template was adopted to induce short hairpin RNA （shRNA）-triggered RNA interference （RNAi） to block periostin gene expression in the cell line U2OS. U2OS cells were divided into three groups： cells transfected with phosphate buffered saline as control group （the U2OS group）, cells transfected with pGCsi as negative control group （the NC group） and cells transfected with periostin/pGCsi as experimental group （the pGCsi-periostin group）. Then, transfection efficiency of cell was observed under fluorescent microscope. The expressions of periostin and the related genes in cells were detected by reverse transcription polymerase chain reaction and Western Blotting. Cell viability was determined using the methyl-thiazolyl tetrazolium bromide （MTT） quantitative colorimetric assay. The invasion and migration capability of cells were tested by transwell plates with or without extracellular matrix gel. Furthermore, the changes of cell cycle and apoptosis were analyzed by flow cytometry.Results The transfection efficiency of periostin/pGCsi to U2OS cells was about 70%-80%. When compared with the NC group, the levels of mRNA and protein of periostin in the pGCsi-periostin group decreased by 82% （F=564.71, P＜0.001） and 58% （F=341.51, P ＜0.001 ）, respectively. Meantime, the earlier apoptosis value increased by 417 （F=28.69,P ＜0.001）. The percentage of S phase pGCsi-periostin cells decreased by 21% （F=47.00, P ＜0.001）, however, that of G0-G1 phase cells increased by 12% （F=14.50, P ＜0.001）. The capability of migration and invasion reduced by 41%（F=17.79, P ＜0.001） and 72% （F=197.08, P ＜0.001）, respectively. The cell proliferation in the pGCsi-periostin group decreased by 59% and 72% at 48 and 120 hours after transfection, respectively. The mRNA expressions of transforming growth factor-β and vascular endothelial growth factor decreased by 17% （F=73.99, P ＜0.001） and 47% （F=30.25, P ＜0.001）, respectively. A tendency of lower focal adhesion kinase （FAK） was shown in pGCsi-periostin cells but without any statistically significant difference. Otherwise the expression of p-FAK in those cells had markedly decreased by 21%（F=16.81, P＜0.001）.Conclusions RNAi against periostin can effectively down-regulate periostin gene expression. Periostin increases the hyperplasia and invasion of cancer cells. Periostin might be involved in and served as a tumor promoter gene in the pathogenesis of osteosarcoma.
基金supported by the Important Hubei Science and Technology Innovation Plan 2015ACA062 (to Xulin Chen)the Natural Science Foundation of Hubei Province (2018CFB244, to Jungang Chen)
文摘Severe influenza infections are often associated with the excessive induction of pro-inflammatory cytokines,which is also referred to as"cytokine storms".Several studies have shown that cytokine storms are directly associated with influenzainduced fatal acute lung injury and acute respiratory distress syndrome.Due to the narrow administration window,current antiviral therapies are often inadequate.The efforts to use immunomodulatory agents alone or in combination with antiviral agents in the treatment of influenza in animal models have resulted in the achievement of protective effects accompanied with reduced cytokine production.Currently,there are no immunomodulatory drugs for influenza available for clinical use.Animal models,despite being ideal to study the anti-inflammatory responses to influenza virus infection,are very costly and time-consuming.Therefore,there is an urgent need to establish fast and economical screening methods using cellbased models to screen and develop novel immunomodulatory agents.In this study,we screened seven human cell lines and found that the human monocytic cell U937 supports the replication of different subtypes of influenza viruses as well as the production of the important pro-inflammatory cytokines and was selected to develop the cell-based model.The U937 cell model was validated by testing a panel of known antiviral and immunomodulatory agents and screening a drug library consisting of 1280 compounds comprised mostly of FDA-approved drugs.We demonstrated that the U937 cell model is robust and suitable for the high-throughput screening of immunomodulators and antivirals against influenza infection.
