18 research outputs found
The Interactions Between Three Typical PPCPs and LDH
With a layered structure, layered double hydroxide (LDH) has potential applications in remediation of anionic contaminants, which has been a hot topic for recent years. In this study, a Cl type Mg-Al hydrotalcite (Cl-LDH) was prepared by a co-precipitation method. The adsorption process of three pharmaceuticals and personal care products (PPCPs) [tetracycline (TC), diclofenac sodium (DF), chloramphenicol (CAP)] by Cl-LDH was investigated by X-ray diffraction (XRD), Zeta potential, dynamic light scattering (DLS), BET, Fourier transform infrared (FTIR) spectroscopy, and molecular dynamics simulation. The results showed that the adsorption equilibrium of TC and DF could be reached in 120 min, and the maximum adsorption capacity of the TC and DF were 1.85 and 0.95 mmol/g, respectively. The isothermal adsorption model of TC was fitted with the Freundlich adsorption model, and the isothermal adsorption model of DF was fitted with the Langmuir adsorption model. The adsorption dynamics of TC and DF followed the pseudo-second-order model. The adsorption mechanisms of the three PPCPs into Cl-LDH were different based on the experimental results and molecular dynamics simulation. The TC adsorption on Cl-LDH was accompanied by the electrostatic interactions between the negative charge of TC and the positive charge of Cl-LDH. The uptake of DF was attributed to anion exchange and electrostatic interaction. Cl-LDH does not adsorb CAP due to no electrostatic interaction. The molecular dynamic simulation further confirmed different configurations of three selected PPCPs, which were ultimately responsible for the uptake of PPCPs on Cl-LDH
Direct syngas conversion to liquefied petroleum gas: Importance of a multifunctional metal-zeolite interface
It is challenging to fabricate a multifunctional catalyst for consecutively catalyzing multiple reactions. Herein, we report a well-defined metal-zeolite interface derived from a CuZnAl@H-Beta core@shell catalyst to realize one-step syngas conversion to liquefied petroleum gas (LPG). The multifunctional interface between CuZnAl core and H-Beta zeolite shell is composed of Cu and acid zeolite with a content gradient, through which synthesized methanol via syngas on the core will pass. The interface is able to catalyze the tandem dehydration of methanol to olefins on acid sites and olefin hydrogenation to C3-4 saturated hydrocarbons (LPG fraction) over exposed Cu sites on the interface instead of noble metals in conventional catalysts. The selectivity of LPG in hydrocarbons over the prepared capsule catalyst reaches as high as 77% accompanied by a record low methane and C-2 selectivity (< 2.0%)
The Immunological Regulation Roles of Porcine β-1, 4 Galactosyltransferase V (B4GALT5) in PRRSV Infection
B4GALT5, also known as β-1, 4 galactosyltransferase V, is one of the members of β-1, 4 galactosyltransferase gene (B4GALT) family, which was concerned with embryonic development, tumor generation, other malignant diseases. In this study, we firstly cloned porcine B4GALT (pB4GALT5) from porcine alveolar macrophages, and predicted the structural domain and function of seven porcine β-1, 4 galactosyltransferase (I–VII) based on transcriptome analysis of PRRSV infected cells. Additionally, the upregulated porcine B4GALT5 expression was detected from PRRSV infected porcine alveolar macrophage (PAM) cells. The PRRSV proliferation were slightly inhibited in overexpression of pB4GALT5 transfected cells, the interaction of B4GALT5 and GP5 of PRRSV was firstly be detected by Co-IP, and the co-location between B4GALT5 and GP5 were also observed in golgi membranes by confocal microscopy. A significant increasing mRNA transcription, including inflammatory cytokines (IFN-α, IL-6, IL-18, IL-1β, TNF-α) and some cell surface glycosylated protein involved in antigen present (MHC-I/II), cell adhesion and migration (chemokine MCP-1 and receptor CCR2; LFA-1, ICAM-1) were upregulated in B4GALT5 overexpressed PRRSV infected cells. Our results demonstrated that the regulation of pB4GALT5 plays an important roles in PRRSV proliferation and modification function in viral infection cells. And these results will make achievements by supporting the research of latent mechanisms of β-1, 4 galactosyltransferase V in antiviral immunity
Activation of EGFR-DNA-PKcs pathway by IGFBP2 protects esophageal adenocarcinoma cells from acidic bile salts-induced DNA damage
Abstract Background The incidence of esophageal adenocarcinoma (EAC) is rising rapidly in the US and Western countries. The development of Barrett’s esophagus (BE) and its progression to EAC have been linked to chronic gastroesophageal reflux disease (GERD). Exposure of BE and EAC cells to acidic bile salts (ABS) in GERD conditions induces high levels of oxidative stress and DNA damage. In this study, we investigated the role of insulin-like growth factor binding protein 2 (IGFBP2) in regulating ABS-induced DNA double-strand breaks. Methods Real-time RT-PCR, western blot, immunohistochemistry, immunofluorescence, co-immunoprecipitation, flow cytometry, and cycloheximide (CHX) chase assays were used in this study. To mimic GERD conditions, a cocktail of acidic bile salts (pH 4) was used in 2D and 3D organotypic culture models. Overexpression and knockdown of IGFBP2 in EAC cells were established to examine the functional and mechanistic roles of IGFBP2 in ABS-induced DNA damage. Results Our results demonstrated high levels of IGFBP2 mRNA and protein in EAC cell lines as compared to precancerous Barrett’s cell lines, and IGFBP2 is frequently overexpressed in EACs (31/57). Treatment of EAC cells with ABS, to mimic GERD conditions, induced high levels of IGFBP2 expression. Knocking down endogenous IGFBP2 in FLO1 cells (with constitutive high levels of IGFBP2) led to a significant increase in DNA double-strand breaks and apoptosis, following transient exposure to ABS. On the other hand, overexpression of exogenous IGFBP2 in OE33 cells (with low endogenous levels of IGFBP2) had a protective effect against ABS-induced double-strand breaks and apoptosis. We found that IGFBP2 is required for ABS-induced nuclear accumulation and phosphorylation of EGFR and DNA-PKcs, which are necessary for DNA damage repair activity. Using co-immunoprecipitation assay, we detected co-localization of IGFBP2 with EGFR and DNA-PKcs, following acidic bile salts treatment. We further demonstrated, using cycloheximide chase assay, that IGFBP2 promotes EGFR protein stability in response to ABS exposure. Conclusions IGFBP2 protects EAC cells against ABS-induced DNA damage and apoptosis through stabilization and activation of EGFR - DNA-PKcs signaling axis
Abstract 878: IGFBP2 is required to activate EGFR-DNA-PKcs pathway to protect esophageal adenocarcinoma cells from acidic bile salts-induced DNA damage
Abstract The incidence of esophageal adenocarcinoma (EAC) is rising rapidly in the US and Western countries. The development of Barrett’s esophagus (BE) and its progression to EAC have been linked to gastroesophageal reflux disease (GERD). Exposure of BE and EAC cells to acidic bile salts (ABS) in GERD conditions induces high levels of DNA damage. In this study, we investigated the role of insulin-like growth factor binding protein 2 (IGFBP2) in regulating ABS-induced DNA double-strand breaks (DSBs). Immunohistochemistry analysis demonstrated frequent overexpression of IGFBP2 in EACs (31/57). Treatment of EAC cells with ABS, to mimic GERD conditions, induced high levels of IGFBP2 expression. Knocking down endogenous IGFBP2 in FLO1 cells (with constitutive high levels of IGFBP2) led to a significant increase in DNA DSBs and apoptosis, following transient exposure (20 min) to ABS. On the other hand, overexpression of exogenous IGFBP2 in OE33 cells (with low endogenous levels of IGFBP2) had a protective effect against DSBs and apoptosis. Using western blotting and immunofluorescence assays, we found that IGFBP2 is required for ABS-induced nuclear accumulation and phosphorylation of EGFR and DNA-PKcs, which are required for DNA damage repair activity. Using co-immunoprecipitation assay, we detected IGFBP2 forms complex with EGFR and DNA-PKcs and co-localizes with EGFR and DNA-PKcs in nucleus, following acidic bile salts treatment. We also demonstrated, using cycloheximide (CHX) chase assay, that IGFBP2 promotes EGFR protein stability in response to ABS exposure. In summary, our data indicate that IGFBP2 protects EAC cells against ABS-induced DNA damage and apoptosis through stabilization and activation of EGFR - DNA-PKcs signaling axis. Citation Format: Zhangjian Zhou, Heng Lu, Shoumin Zhu, Ahmed Gomaa, Zheng Chen, Jin Yan, Wael El-Rifai, Chengxue Dang, Dunfa Peng. IGFBP2 is required to activate EGFR-DNA-PKcs pathway to protect esophageal adenocarcinoma cells from acidic bile salts-induced DNA damage [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 878
Presentation1.pdf
<p>With a layered structure, layered double hydroxide (LDH) has potential applications in remediation of anionic contaminants, which has been a hot topic for recent years. In this study, a Cl type Mg-Al hydrotalcite (Cl-LDH) was prepared by a co-precipitation method. The adsorption process of three pharmaceuticals and personal care products (PPCPs) [tetracycline (TC), diclofenac sodium (DF), chloramphenicol (CAP)] by Cl-LDH was investigated by X-ray diffraction (XRD), Zeta potential, dynamic light scattering (DLS), BET, Fourier transform infrared (FTIR) spectroscopy, and molecular dynamics simulation. The results showed that the adsorption equilibrium of TC and DF could be reached in 120 min, and the maximum adsorption capacity of the TC and DF were 1.85 and 0.95 mmol/g, respectively. The isothermal adsorption model of TC was fitted with the Freundlich adsorption model, and the isothermal adsorption model of DF was fitted with the Langmuir adsorption model. The adsorption dynamics of TC and DF followed the pseudo-second-order model. The adsorption mechanisms of the three PPCPs into Cl-LDH were different based on the experimental results and molecular dynamics simulation. The TC adsorption on Cl-LDH was accompanied by the electrostatic interactions between the negative charge of TC and the positive charge of Cl-LDH. The uptake of DF was attributed to anion exchange and electrostatic interaction. Cl-LDH does not adsorb CAP due to no electrostatic interaction. The molecular dynamic simulation further confirmed different configurations of three selected PPCPs, which were ultimately responsible for the uptake of PPCPs on Cl-LDH.</p
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From hydrophilic to hydrophobic: A promising approach to tackle high CO2 selectivity of Fe-based Fischer-Tropsch microcapsule catalysts
Zeolite supported Fischer-Tropsch (FT) catalysis has attracted extensive attentions in past few years. Capsule catalysts have unique characteristics of tuning product selectivity more precisely and enhancing stability of catalysts during reaction, which makes them to stand out of the crowed. Fe-based FT catalysts have been facing limitations for syngas conversion to hydrocarbons with their associated problems of high CO2 selectivity and rapid catalyst deactivation. A series of ZSM-5 supported Fe-based microcapsule catalysts, composed of Fe/ZSM-5 core and silicalite-1 shell, was prepared and employed for direct synthesis of gasoline range hydrocarbons from syngas. Tuning silicalite-1 shell thickness significantly affected water-gas shift reaction with increasing hydrophobicity of catalyst surface, and greatly decreased CO2 selectivity. The microcapsule catalysts significantly suppressed the CO2 selectivity as compared with supported Fe-based catalyst. Moreover, all zeolite supported Febased catalysts, showed significantly high gasoline range hydrocarbons selectivity (about 60%). The proposed catalyst design suggests a promising approach to overcome high CO2 selectivity challenge associated with Febased FT catalysts