94 research outputs found

    Intracellular Delivery of Recombinant alpha B-crystallin into Neonatal Rat Cardiomyocytes has a Protective Effect on the Cells

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    In order to deliver alpha B-crystallin (alpha B-C) into cardiomyocytes and study its cellular protection, the full-length cDNA fragment encoding human alpha B-C was cloned into the bacterial expression vector pGEX-MTS containing the base sequence of membrane-translocating sequence (MTS) which mediates intracellular delivery of peptides and expressed as a fusion protein coupled to glutathione S-transferase (GST).After glutathione affinity chromatography and cleaved from GST by factor Xa, the recombinant MTS- alpha B-C was separated from GST and factor Xa by anion exchange chromatography. Recombinant MTS- alpha B-C was characterized by SDS-PAGE and Western immunoblot analysis. The purified MTS- alpha B-C migrated on SDS-PAGE as a single band to an apparent molecular weight (Mr.23kD) that corresponded to total native alpha B-C plus MTS, and was recognized on Western immunoblot by anti-human alpha B-crystallin antibody. MTS- alpha B-C displayed chaperone-like function in an ATP-containing buffer at 37? by disaggregating the denatured and aggregated actin induced by hydrogen peroxide (H2O2 )treatment. It was observed under fluorescence microscope that FITC-labeled MTS- alpha B-C had gone into neonatal rat cardiomyocytes by MTS mediation after the cells were incubated with it for 6 hours while FITC-labeled alpha B-C and bovine serum albumin had not gone into the cells. Recombinant MTS- alpha B-C is not cytotoxic, and MTS- alpha B-C-treated cells displayed increased H2O2-tolerance compared with non-treated cells

    The effects of aB-crystallin on mitochondrial death pathway during hydrogen peroxide induced apoptosis

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    aB-crystallin, a major small heat shock protein, has recently been shown to exert inhibitory effects on apoptosis, while the responsible mechanisms remain largely unknown. In the present study, we discovered that aB-crystallin protected mouse myoblast C2C12 cells against oxidative stress-induced apoptosis. During hydrogen peroxide-induced apoptosis, aBcrystallin showed that it decreased the redistribution level of phosphatidylserine (PS), reduced the release of cytochrome C and Smac/Diablo from mitochondria into cytoplasm, and decreased the cleavage of Bid. Interestingly, immunoprecipitation experiments with anti-aBcrystallin and anti-myc-tag antibodies demonstrated respectively an interaction between aBcrystallin and p53 during hydrogen peroxide induced apoptosis. Both the NH2-terminal and COOH-terminal regions of aB-crystallin could interact with p53, suggesting two domains of aB-crystallin are necessary for the interaction. Electrophoresis mobility shift assay (EMSA) and luciferase assay further demonstrated that aB-crystallin inhibited the upregulation of the DNA-binding, as well as the transactivation activity of p53 induced by hydrogen peroxide. Our results show that aB-crystallin has a protective role in oxidative stress induced apoptosis by interference with the mitochondrial death pathway

    The Spatially Resolved Properties of the GW170817 Host Galaxy

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    GW170817 is the unique gravitational-wave (GW) event that is associated to the electromagnetic (EM) counterpart GRB 170817A. NGC 4993 is identified as the host galaxy of GW170817/GRB 170817A. In this paper, we particularly focus on the spatially resolved properties of NGC 4993. We present the photometric results from the comprehensive data analysis of the high spatial-resolution images in the different optical bands. The morphological analysis reveals that NGC 4993 is a typical early-type galaxy without significant remnants of major galaxy merger. The spatially resolved stellar population properties of NGC 4993 suggest that the galaxy center has passive evolution with the outskirt formed by gas accretion. We derive the merging rate of the compact object per galaxy by a co-evolution scenario of supermassive black hole and its host galaxy. If the galaxy formation is at redshift 1.0, the merging rate per galaxy is 3.2×1043.2\times 10^{-4} to 7.7×1057.7\times 10^{-5} within the merging decay time from 1.0 to 5.0 Gyr. The results provide the vital information for the ongoing GW EM counterpart detections. The HST data analysis presented in this paper can be also applied for the Chinese Space Station Telescope (CSST) research in the future.Comment: RAA accepte

    HSP70: a promising target for laryngeal carcinoma radiaotherapy by inhibiting cleavage and degradation of nucleolin

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    Previous studies have shown that heat shock proteins (HSPs) were upregulated in various types of tumors and were associated with histological grade, recurrence and metastasis of malignant tumors. In this study, we investigated whether heat shock protein 70 kDa (HSP70) was associated with histological grade of laryngeal squamous cell carcinomas (LSCC). We also determine the role of HSP70 in LSCC radiation resistance using a laryngeal carcinoma xenograft model by antisense HSP70 RNA technique. Immunohistochemistry data showed that HSP70 was detected in 96% of LSCC tissues (48 out of 50). The expression level of HSP70 was significantly lower in early stage of LSCC than that in late stage (P = 0.015). Radiation treatment result showed that the volumes and weights of implantation tumors in the group injected with antisense HSP70 oligos were significantly reduced comparing to the group injected with random oligos(p < 0.05). In addition, cleavage and degradation of tumor nucleolin in antisense HSP70 oligos injection group was significantly higher than that in random oligos injection group. Our result suggested that HSP70 may play a role in LSCC radiotherapy resistance by inhibiting cleavage and degradation of nucleolin

    Effect of acidification treatment on the extraction performance of coking coal

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    In order to study the influence mechanism of minerals removal from coal on solvent extraction behavior, different concentrations of tetrahydrofuran (THF) solvents were used to extract coking coal before and after acidification with hydrochloric acid (HCl) and hydrofluoric acid (HF). With the help of conventional coal quality analysis and GC-MS test methods, the differences of THF extraction rate and extract composition before and after demineralization of coal samples were analyzed, and the influence mechanism of solvent concentration, extraction time, temperature and minerals was discussed. The results show that: ①After acidification, the ash yield of coal sample reaches 97.3%, the content decreases significantly, the fixed carbon content increases by 21%, the volatile content increases relatively, but the moisture content remains basically unchanged; The contents of C and H decrease, while the contents of O, N and S increase, among which the contents of C and O change significantly. ②The extraction rate of coal samples after acidification increase significantly, but with the increase of THF concentration, the increase of extraction rate show a decreasing trend. The same extraction effect is achieved under the same conditions, and the extraction time of acidified coal is 1.25~5 times faster than that of raw coal; Acidification treatment enlarges the effect of temperature on extraction rate, which makes the extraction advantage at 35 ℃ more obvious. ③The relative content of heteroatom compounds in raw coal extracts is the highest, while aliphatic hydrocarbons are the main components in acidified coal extracts, among which the content of straight chain hydrocarbons increases with the increase of THF concentration, accounting for 91.92% of the total content. The number of carbon atoms is mainly concentrated in C15~C22, but the number of extracted species is significantly less than that of raw coal. Generally speaking, acidification treatment can effectively improve the extraction capacity of THF, greatly shorten the extraction time, and improve the extraction capacity of high carbon alkanes in coal. In addition, although water does not dominate the extraction process, it will also affect the extraction ability of THF to a certain extent, making the extraction ability of low concentration THF solvent better than that of pure THF solvent

    High-resolution grayscale image hidden in a laser beam

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    Images perceived by human eyes or recorded by cameras are usually optical patterns with spatially varying intensity or color profiles. In addition to the intensity and color, the information of an image can be encoded in a spatially varying distribution of phase or polarization state. Interestingly, such images might not be able to be directly viewed by human eyes or cameras because they may exhibit highly uniform intensity profiles. Here, we propose and experimentally demonstrate an approach to hide a high-resolution grayscale image in a square laser beam with a size of less than half a millimeter. An image with a pixel size of 300 × 300 nm is encoded into the spatially variant polarization states of the laser beam, which can be revealed after passing through a linear polarizer. This unique technology for hiding grayscale images and polarization manipulation provides new opportunities for various applications, including encryption, imaging, optical communications, quantum science and fundamental physics

    Expression of Mipu1 in Response to Myocardial Infarction in Rats

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    Myocardial ischemic preconditioning up-regulated protein 1 (Mipu1) was cloned in our laboratory. Male Wistar rats were subjected to left anterior coronary artery ligation and sham-operation and sacrificed at 1 h, 3 h, 6 h, 12 h, 24 h, 3 d or 5 d after ligation. Expression of Mipu1 mRNA and protein were assessed by Northern blotting, real-time quantitative RT-PCR, In Situ hybridization and Western blotting. Expression of Mipu1 was up-regulated at 3 h and lasted to 12 h with a peak at 6 h. Mipu1 mRNA and protein signals express in the endothelium and myocardium in normal and infarcted heart, mainly in infarcted zone. Fluorescent immunocytochemistry showed that Mipu1 protein was localized to the nuclei of H9c2 myogenic cells and was upregulated after the cells being exposed to H2O2. These observations indicates that Mipu1 may play a role in maintaining vascular homeostasis and protecting the myogenic cells from being injured by ischemia-reperfusion or oxidation stress
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