1,450 research outputs found

    The P Protein of Spring Viremia of Carp Virus Negatively Regulates the Fish Interferon Response by Inhibiting the Kinase Activity of TANK-Binding Kinase 1

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    Spring viremia of carp virus (SVCV) is an efficient pathogen causing high mortality in the common carp. Fish interferon (IFN) is a powerful cytokine enabling host cells to establish an antiviral response; therefore, the strategies that SVCV uses to avoid the cellular IFN response were investigated. Here, we report that the SVCV P protein is phosphorylated by cellular TANK-binding kinase 1 (TBK1), which decreases IFN regulatory factor 3 (IRF3) phosphorylation and suppresses IFN production. First, overexpression of P protein inhibited the IFN promoter activation induced by SVCV and the IFN activity activated by the mitochondrial antiviral signaling protein (MAVS) although TBK1 activity was not blocked by P protein. Second, P protein colocalized and interacted with TBK1. Dominant negative experiments suggested that the TBK1 N-terminal kinase domain interacted with P protein and was essential for P protein and IRF3 phosphorylation. Finally, P protein overexpression reduced the IRF3 phosphorylation activated by TBK1 and reduced host cellular ifn transcription. Collectively, our data demonstrated that the SVCV P protein is a decoy substrate for the host phosphokinase TBK1, preventing IFN production and facilitating SVCV replication. IMPORTANCE TBK1 is a pivotal phosphokinase that activates host IFN production to defend against viral infection; thus, it is a potential target for viruses to negatively regulate IFN response and facilitate viral evasion. We report that the SVCV P protein functions as a decoy substrate for cellular TBK1, leading to the reduction of IRF3 phosphorylation and suppression of IFN expression. These findings reveal a novel immune evasion mechanism of SVCV.</p

    MicroRNA 506 regulates expression of PPAR alpha in hydroxycamptothecin-resistant human colon cancer cells

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    AbstractChemotherapeutic drug resistance remains a major obstacle to the successful treatment of colon cancer. Here, we show that 77 differentially expressed miRNAs were identified in SW1116/HCPT versus SW1116, and over-expressed miR-506 in SW1116/HCPT cells was validated. Then it was indicated that PPARα is a common target of miR-506 by using a luciferase reporter assay. Our results also demonstrated that cytotoxic ability of HCPT requires the concomitant presence of PPARα, and that loss of PPARα expression imparts resistance to HCPTs anti-tumor effects. All together, our studies indicate that miR-506 over-expression in established HCPT-resistant colon cancer cell line confers resistance to HCPT by inhibiting PPARα expression, then providing a rationale for the development of miRNA-based strategies for reversing resistance in HCPT-resistant colon cancer cells

    A Text-guided Protein Design Framework

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    Current AI-assisted protein design mainly utilizes protein sequential and structural information. Meanwhile, there exists tremendous knowledge curated by humans in the text format describing proteins' high-level functionalities. Yet, whether the incorporation of such text data can help protein design tasks has not been explored. To bridge this gap, we propose ProteinDT, a multi-modal framework that leverages textual descriptions for protein design. ProteinDT consists of three subsequent steps: ProteinCLAP which aligns the representation of two modalities, a facilitator that generates the protein representation from the text modality, and a decoder that creates the protein sequences from the representation. To train ProteinDT, we construct a large dataset, SwissProtCLAP, with 441K text and protein pairs. We quantitatively verify the effectiveness of ProteinDT on three challenging tasks: (1) over 90\% accuracy for text-guided protein generation; (2) best hit ratio on 10 zero-shot text-guided protein editing tasks; (3) superior performance on four out of six protein property prediction benchmarks

    A Leucine Aminopeptidase-Activated Theranostic Prodrug for Cancer Diagnosis and Chemotherapy

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    Currently, chemotherapy is a widely used and important treatment for cancer. However, almost all of the treatments have shortcomings associated with poor specificity and high toxicity, which results in severe side effects to normal cells and tissue. This is a very important problem, and yet, it currently remains unanswered. Therefore, the development of the method for the more effective delivery of anticancer drugs to their targets and real-time monitoring of the localization of the drugs are very important. Herein, we designed a theranostic prodrug: CPT-p-Leu, which was constructed using fluorescent camptothecin (CPT), a self-immolative linker and leucine (Leu) residue. Upon exposure to LAP (leucine aminopeptidase: LAP), the amide bond in CPT-p-Leu will be cleaved, followed by an intramolecular 1,6-elimination, which triggers the active anticancer drug (CPT) release and recovers the fluorescence of CPT. With our design, the anticancer drug, CPT, can be used as both a drug and a fluorescence reporter, making our system suitable to accurately and effectively track the released CPT distribution. Based on this strategy, CPT-p-Leu could achieve the chemoselective detection of LAP and monitoring of the anticancer drug release. Furthermore, it also provides a very convenient way to accurately determine the location of the released drug in living samples. In addition, CPT-p-Leu shows a good cell membrane permeability and enhanced cytotoxicity toward LAP overexpressing cancer cells. We anticipate that our research will facilitate the development of improved theranostic systems for cancer therapy.</p

    A Leucine Aminopeptidase-Activated Theranostic Prodrug for Cancer Diagnosis and Chemotherapy

    Get PDF
    Currently, chemotherapy is a widely used and important treatment for cancer. However, almost all of the treatments have shortcomings associated with poor specificity and high toxicity, which results in severe side effects to normal cells and tissue. This is a very important problem, and yet, it currently remains unanswered. Therefore, the development of the method for the more effective delivery of anticancer drugs to their targets and real-time monitoring of the localization of the drugs are very important. Herein, we designed a theranostic prodrug: CPT-p-Leu, which was constructed using fluorescent camptothecin (CPT), a self-immolative linker and leucine (Leu) residue. Upon exposure to LAP (leucine aminopeptidase: LAP), the amide bond in CPT-p-Leu will be cleaved, followed by an intramolecular 1,6-elimination, which triggers the active anticancer drug (CPT) release and recovers the fluorescence of CPT. With our design, the anticancer drug, CPT, can be used as both a drug and a fluorescence reporter, making our system suitable to accurately and effectively track the released CPT distribution. Based on this strategy, CPT-p-Leu could achieve the chemoselective detection of LAP and monitoring of the anticancer drug release. Furthermore, it also provides a very convenient way to accurately determine the location of the released drug in living samples. In addition, CPT-p-Leu shows a good cell membrane permeability and enhanced cytotoxicity toward LAP overexpressing cancer cells. We anticipate that our research will facilitate the development of improved theranostic systems for cancer therapy.</p

    Analysis of retinal vasculature changes in indirect traumatic optic neuropathy using optic coherence tomography angiography

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    AIM: To assess the retinal vasculature alterations in indirect traumatic optic neuropathy (ITON) patients following craniofacial trauma by optic coherence tomography angiography (OCTA). METHODS: Patients diagnosed of monocular ITON were recruited from August 2016 to May 2020. OCTA was performed using the AngioVue OCT-A system for two cube scans centered at the optic nerve head and fovea. OCTA data included thicknesses of peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell complex (GCC), as well as proportion of capillary perfusion and data were analyzed for correlation with post-injury timepoints: within 7, 8-30, 31-90, and 91-365d. RESULTS: A total of 73 ITON patients were studied. Significant thinning of RNFL and GCC layers and attenuation of microvascular perfusion were observed in ITON eyes as compared to contralateral unaffected eyes (for most of the analyzed sectors and quadrants, P<0.05). Without respect to surgical intervention and vision recovery, the decrease in retinal layer thicknesses and microvascular perfusion was time-dependent, and most significant within three months (P<0.001). CONCLUSION: ITON presents with time-dependent thinning of retinal layers and attenuation of microvasculature, indicating possible degeneration of retinal ganglion cells due to reduced retinal blood supply

    Effect of acute exposure of Hg on physiological parameters and transcriptome expression in silkworms (Bombyx mori)

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    Mercury (Hg) contamination poses a global threat to the environment, given its elevated ecotoxicity. Herein, we employed the lepidopteran model insect, silkworm (Bombyx mori), to systematically investigate the toxic effects of Hg-stress across its growth and development, histomorphology, antioxidant enzyme activities, and transcriptome responses. High doses of Hg exposure induced evident poisoning symptoms, markedly impeding the growth of silkworm larvae and escalating mortality in a dose-dependent manner. Under Hg exposure, the histomorphology of both the midgut and fat body exhibited impairments. Carboxylesterase (CarE) activity was increased in both midgut and fat body tissues responding to Hg treatment. Conversely, glutathione S-transferase (GST) levels increased in the fat body but decreased in the midgut. The transcriptomic analysis revealed that the response induced by Hg stress involved multiple metabolism processes. Significantly differently expressed genes (DEGs) exhibited strong associations with oxidative phosphorylation, nutrient metabolisms, insect hormone biosynthesis, lysosome, ribosome biogenesis in eukaryotes, and ribosome pathways in the midgut or the fat body. The findings implied that exposure to Hg might induce the oxidative stress response, attempting to compensate for impaired metabolism. Concurrently, disruptions in nutrient metabolism and insect hormone activity might hinder growth and development, leading to immune dysfunction in silkworms. These insights significantly advance our theoretical understanding of the potential mechanisms underlying Hg toxicity in invertebrate organisms
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