35 research outputs found

    Human Papillomavirus Type 18 E6 and E7 Genes Integrate into Human Hepatoma Derived Cell Line Hep G2

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    Background and Objectives: Human papillomaviruses have been linked causally to some human cancers such as cervical carcinoma, but there is very little research addressing the effect of HPV infection on human liver cells. We chose the human hepatoma derived cell line Hep G2 to investigate whether HPV gene integration took place in liver cells as well. Methods: We applied PCR to detect the possible integration of HPV genes in Hep G2 cells. We also investigated the expression of the integrated E6 and E7 genes by using RT-PCR and Western blotting. Then, we silenced E6 and E7 expression and checked the cell proliferation and apoptosis in Hep G2 cells. Furthermore, we analyzed the potential genes involved in cell cycle and apoptosis regulatory pathways. Finally, we used in situ hybridization to detect HPV 16/18 in hepatocellular carcinoma samples. Results: Hep G2 cell line contains integrated HPV 18 DNA, leading to the expression of the E6 and E7 oncogenic proteins. Knockdown of the E7 and E6 genes expression reduced cell proliferation, caused the cell cycle arrest at the S phase, and increased apoptosis. The human cell cycle and apoptosis real-time PCR arrays analysis demonstrated E6 and E7-mediated regulation of some genes such as Cyclin H, UBA1, E2F4, p53, p107, FASLG, NOL3 and CASP14. HPV16/18 was found in only 9% (9/100) of patients with hepatocellular carcinoma. Conclusion: Our investigations showed that HPV 18 E6 and E7 genes can be integrated into the Hep G2, and we observed a low prevalence of HPV 16/18 in hepatocellular carcinoma samples. However, the precise risk of HPV as causative agent of hepatocellular carcinoma needs further study

    The enormous repetitive Antarctic krill genome reveals environmental adaptations and population insights

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    Antarctic krill (Euphausia superba) is Earth’smost abundant wild animal, and its enormous biomass is vital to the Southern Ocean ecosystem. Here, we report a 48.01-Gb chromosome-level Antarctic krill genome, whose large genome size appears to have resulted from inter-genic transposable element expansions. Our assembly reveals the molecular architecture of the Antarctic krill circadian clock and uncovers expanded gene families associated with molting and energy metabolism, providing insights into adaptations to the cold and highly seasonal Antarctic environment. Population-level genome re-sequencing from four geographical sites around the Antarctic continent reveals no clear population structure but highlights natural selection associated with environmental variables. An apparent drastic reduction in krill population size 10 mya and a subsequent rebound 100 thousand years ago coincides with climate change events. Our findings uncover the genomic basis of Antarctic krill adaptations to the Southern Ocean and provide valuable resources for future Antarctic research

    Dynamic Phase Signal Control Method for Unstable Asymmetric Traffic Flow at Intersections

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    This paper addresses the limitations that the phases proposed in variable phase sequencing studies for stochastic traffic flow are all predetermined and that the variable phase sequencing is only suitable for low traffic volume environment. It presents a dynamic phase signal control method for unstable asymmetric traffic flow with two primary operational objectives: the realization of a dynamic phase scheme in each cycle and optimization of signal control parameters. First, an asymmetric state of traffic flow at signalized intersections is defined, rules governing the generation of the dynamic phase of each cycle based on asymmetric state are proposed, and the delay variations of intersections adopting dynamic phase schemes are modeled. Next, a signal control parameter adjustment algorithm for the dynamic phase is constructed to maximize the positive benefits of delay variation. Last, the operational performance of the proposed method is validated using data collected from an intersection in Harbin, China, by VISSIM simulation. Furthermore, it is found that a higher asymmetric coefficient leads to lower efficiency of a symmetrical release phase scheme at intersections, and the increase of average delay becomes significant when the asymmetric coefficient threshold is greater than 0.2

    The Involvement of Ubiquitination and SUMOylation in Retroviruses Infection and Latency

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    Retroviruses, especially the pathogenic human immunodeficiency virus type 1 (HIV-1), have severely threatened human health for decades. Retroviruses can form stable latent reservoirs via retroviral DNA integration into the host genome, and then be temporarily transcriptional silencing in infected cells, which makes retroviral infection incurable. Although many cellular restriction factors interfere with various steps of the life cycle of retroviruses and the formation of viral latency, viruses can utilize viral proteins or hijack cellular factors to evade intracellular immunity. Many post-translational modifications play key roles in the cross-talking between the cellular and viral proteins, which has greatly determined the fate of retroviral infection. Here, we reviewed recent advances in the regulation of ubiquitination and SUMOylation in the infection and latency of retroviruses, focusing on both host defense- and virus counterattack-related ubiquitination and SUMOylation system. We also summarized the development of ubiquitination- and SUMOylation-targeted anti-retroviral drugs and discussed their therapeutic potential. Manipulating ubiquitination or SUMOylation pathways by targeted drugs could be a promising strategy to achieve a “sterilizing cure” or “functional cure” of retroviral infection

    Non-coding RNAs and retroviruses

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    Abstract Retroviruses can cause severe diseases such as cancer and acquired immunodeficiency syndrome. A unique feature in the life cycle of retroviruses is that their RNA genome is reverse transcribed into double-stranded DNA, which then integrates into the host genome to exploit the host machinery for their benefits. The metazoan genome encodes numerous non-coding RNAs (ncRNA), which act as key regulators in essential cellular processes such as antiviral response. The development of next-generation sequencing technology has greatly accelerated the detection of ncRNAs from viruses and their hosts. ncRNAs have been shown to play important roles in the retroviral life cycle and virus–host interactions. Here, we review recent advances in ncRNA studies with special focus on those have changed our understanding of retroviruses or provided novel strategies to treat retrovirus-related diseases. Many ncRNAs such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are involved in the late phase of the retroviral life cycle. However, their roles in the early phase of viral replication merit further investigations

    Silencing of Tumor Necrosis Factor Receptor 1 by siRNA in EC109 Cells Affects Cell Proliferation and Apoptosis

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    Tumor necrosis factor receptor 1 (TNFR1) is a membrane receptor able to bind TNF-α or TNF-ÎČ. TNFR1 can suppress apoptosis by activating the NF-ÎșB or JNK/SAPK signal transduction pathway, or it can induce apoptosis through a series of caspase cascade reactions; the particular effect may depend on the cell line. In the present study, we first showed that TNFR1 is expressed at both the gene and protein levels in the esophageal carcinoma cell line EC109. Then, by applying a specific siRNA, we silenced the expression of TNFR1; this resulted in a significant time-dependent promotion of cell proliferation and downregulation of the apoptotic rate. These results suggest that TNFR1 is strongly expressed in the EC109 cell line and that it may play an apoptosis-mediating role, which may be suppressed by highly activated NF-ÎșB

    Predictive analysis on zigzag maneuverability of small saildrone

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    [Objectives] The maneuverability prediction of small saildrone plays a key role in achieving intelligent tracking and navigation. In order to study the relationship between rudder angle and hull motion, and to predict the maneuverability accurately,[Methods] in this paper, the numerical simulation method is used to systematically study the ship-rudder oblique viscous flow field model and hydrodynamic properties of saildrone. Before simulation of hydrodynamic properties of ship-rudder system, the numerical calculation results and theoretical method of the hull and open water rudder are preliminarily validated. Then the numerical calculation of ship-rudder oblique viscous flow field of saildrone is carried out. Finally,the MMG (ship manoeuvring mathematical model group) method is used to establish the maneuver motion model of the saildrone. The fourth-order Runge-Kutta method is used to solve the differential equation. The influence of the rudder on the maneuverability of the hull is analyzed by simulating the hull zigzag navigation.[Results] The results show that it is feasible to predict the maneuverability of the saildrone with CFD method.[Conclusions] The maneuverability of the hull is applicable for the safe navigation of saildrone in defined conditions

    Phenothiazines Inhibit SARS-CoV-2 Entry through Targeting Spike Protein

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    Novel coronavirus disease 2019 (COVID-19), a respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has brought an unprecedented public health crisis and continues to threaten humanity due to the persistent emergence of new variants. Therefore, developing more effective and broad-spectrum therapeutic and prophylactic drugs against infection by SARS-CoV-2 and its variants, as well as future emerging CoVs, is urgently needed. In this study, we screened several US FDA-approved drugs and identified phenothiazine derivatives with the ability to potently inhibit the infection of pseudotyped SARS-CoV-2 and distinct variants of concern (VOCs), including B.1.617.2 (Delta) and currently circulating Omicron sublineages XBB and BQ.1.1, as well as pseudotyped SARS-CoV and MERS-CoV. Mechanistic studies suggested that phenothiazines predominantly inhibited SARS-CoV-2 pseudovirus (PsV) infection at the early stage and potentially bound to the spike (S) protein of SARS-CoV-2, which may prevent the proteolytic cleavage of the S protein, thereby exhibiting inhibitory activity against SARS-CoV-2 infection. In summary, our findings suggest that phenothiazines can serve as a potential broad-spectrum therapeutic drug for the treatment of SARS-CoV-2 infection as well as the infection of future emerging human coronaviruses (HCoVs)

    Molecular and Functional Characterization of a Polygalacturonase-Inhibiting Protein from <i>Cynanchum komarovii</i> That Confers Fungal Resistance in Arabidopsis

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    <div><p>Compliance with ethical standards: This study did not involve human participants and animals, and the plant of interest is not an endangered species.</p><p>Polygalacturonase-inhibiting proteins (PGIPs) are leucine-rich repeat proteins that plants produce against polygalacturonase, a key virulence agent in pathogens. In this paper, we cloned and purified CkPGIP1, a gene product from <i>Cynanchum komarovii</i> that effectively inhibits polygalacturonases from <i>Botrytis cinerea</i> and <i>Rhizoctonia solani</i>. We found the expression of <i>CkPGIP1</i> to be induced in response to salicylic acid, wounding, and infection with <i>B</i>. <i>cinerea</i> and <i>R</i>. <i>solani</i>. In addition, transgenic overexpression in Arabidopsis enhanced resistance against <i>B</i>. <i>cinerea</i>. Furthermore, CkPGIP1 obtained from transgenic Arabidopsis inhibited the activity of <i>B</i>. <i>cinerea</i> and <i>R</i>. <i>solani</i> polygalacturonases by 62.7–66.4% and 56.5–60.2%, respectively. Docking studies indicated that the protein interacts strongly with the B1-sheet at the N-terminus of the <i>B</i>. <i>cinerea</i> polygalacturonase, and with the C-terminus of the polygalacturonase from <i>R</i>. <i>solani</i>. This study highlights the significance of CkPGIP1 in plant disease resistance, and its possible application to manage fungal pathogens.</p></div

    Inhibitory activity of crude protein extracts from wild type and transgenic Arabidopsis.

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    <p>Inhibitory activity was measured against <i>Botrytis cinerea</i> (<b>A</b>) and <i>Rhizoctonia solani</i> polygalacturonase (<b>B</b>). a-c, 15 ÎŒL crude enzyme + 15 ÎŒg crude protein extract from wild type and transgenic Arabidopsis lines 9 and 14; d-f, 15 ÎŒL crude enzyme + 15 ÎŒg heat-denatured crude protein extract from wild type and transgenic Arabidopsis lines 9 and 14; g, crude PGs. <b>C.</b> Inhibition rate of crude protein extracts from wild type and transgenic Arabidopsis. Error bars indicate standard error (n = 3). **, <i>P</i> < 0.01 by least significant difference against wild type.</p
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