29 research outputs found

    Beauvericin counteracted multi-drug resistant Candida albicans by blocking ABC transporters

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    AbstractMulti-drug resistance of pathogenic microorganisms is becoming a serious threat, particularly to immunocompromised populations. The high mortality of systematic fungal infections necessitates novel antifungal drugs and therapies. Unfortunately, with traditional drug discovery approaches, only echinocandins was approved by FDA as a new class of antifungals in the past two decades. Drug efflux is one of the major contributors to multi-drug resistance, the modulator of drug efflux pumps is considered as one of the keys to conquer multi-drug resistance. In this study, we combined structure-based virtual screening and whole-cell based mechanism study, identified a natural product, beauvericin (BEA) as a drug efflux pump modulator, which can reverse the multi-drug resistant phenotype of Candida albicans by specifically blocking the ATP-binding cassette (ABC) transporters; meantime, BEA alone has fungicidal activity in vitro by elevating intracellular calcium and reactive oxygen species (ROS). It was further demonstrated by histopathological study that BEA synergizes with a sub-therapeutic dose of ketoconazole (KTC) and could cure the murine model of disseminated candidiasis. Toxicity evaluation of BEA, including acute toxicity test, Ames test, and hERG (human ether-à-go-go-related gene) test promised that BEA can be harnessed for treatment of candidiasis, especially the candidiasis caused by ABC overexpressed multi-drug resistant C. albicans

    Microfluidic Platform for Investigating Osteocyte Mechanoregulation of Breast Cancer Bone Metastasis

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    Bone metastasis is a severe complication that occurs in approximately 85% of patients with advanced breast cancer. Although the potential of exercise in attenuating metastatic tumor growth in bone had been shown in vivo, the role of mechanical loading on bone in preventing bone metastasis remains unknown. Osteocytes, as the major mechanosensory bone cells, are identified regulators in mediating loading inhibited bone metastasis in vitro. However, there is no ideal platform currently available for investigating the impact and mechanism underlying loading reduced bone metastasis. To bridge the gap between in vivo and in vitro experiments, this thesis develops a novel microfluidic cancer extravasation platform that integrates bone mechanical loading and real-time bi-directional signaling between multiple cell populations within the bone metastasis environment. Using our microfluidic extravasation platform, we observed the overall effect that mechanically-stimulated osteocytes regulate breast cancer transendothelial extravasation indeed, and the specific impact is breast cancer type dependent.M.A.S

    Forecasting the Volatility of European Union Allowance Futures with Climate Policy Uncertainty Using the EGARCH-MIDAS Model

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    We propose the EGARCH-MIDAS-CPU model, which incorporates the leverage effect and climate policy uncertainty (CPU) to model and forecast European Union allowance futures’ (EUAF) volatility. An empirical analysis based on the daily data of the EUAF price index and the monthly data of the CPU index using the EGARCH-MIDAS-CPU model shows that the EUAF’s volatility exhibits a leverage effect, and the CPU has a significantly negative impact on the EUAF’s volatility. Furthermore, out-of-sample analysis based on three loss functions and the Model Confidence Set (MCS) test suggests that EGARCH-MIDAS-CPU model yields more accurate out-of-sample volatility forecasting results than various competing models. There is room for further application of the model, such as this model could be applied to price carbon futures, so as to improve the liquidity of the carbon market and achieve carbon peak and carbon neutrality as soon as possible

    Population Structure and Selection Signatures Underlying Domestication Inferred from Genome-Wide Copy Number Variations in Chinese Indigenous Pigs

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    Single nucleotide polymorphism was widely used to perform genetic and evolution research in pigs. However, little is known about the effect of copy number variation (CNV) on characteristics in pigs. This study performed a genome-wide comparison of CNVs between Wannan black pigs (WBP) and Asian wild boars (AWB), using whole genome resequencing data. By using Manta, we detected in total 28,720 CNVs that covered approximately 1.98% of the pig genome length. We identified 288 selected CNVs (top 1%) by performing Fst statistics. Functional enrichment analyses for genes located in selected CNVs were found to be muscle related (NDN, TMOD4, SFRP1, and SMYD3), reproduction related (GJA1, CYP26B1, WNT5A, SRD5A2, PTPN11, SPEF2, and CCNB1), residual feed intake (RFI) related (MAP3K5), and ear size related (WIF1). This study provides essential information on selected CNVs in Wannan black pigs for further research on the genetic basis of the complex phenotypic and provides essential information for direction in the protection and utilization of Wannan black pig

    Interrogation of Streptomyces avermitilis for efficient production of avermectins

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    AbstractThe 2015 Nobel Prize in Physiology or Medicine has been awarded to avermectins and artemisinin, respectively. Avermectins produced by Streptomyces avermitilis are excellent anthelmintic and potential antibiotic agents. Because wild-type strains only produce low levels of avermectins, much research effort has focused on improvements in avermectin production to meet the ever increasing demand for such compounds. This review describes the strategies that have been widely employed and the future prospects of synthetic biology applications in avermectin yield improvement. With the help of genome sequencing of S. avermitilis and an understanding of the avermectin biosynthetic/regulatory pathways, synthetic and systems biotechnology approaches have been applied for precision engineering. We focus on the design and synthesis of biological chassis, parts, devices, and modules from diverse microbes to reconstruct and optimize their dynamic processes, as well as predict favorable effective overproduction of avermectins by a 4Ms strategy (Mine, Model, Manipulation, and Measurement)

    BTF3 sustains cancer stem-like phenotype of prostate cancer via stabilization of BMI1

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    Abstract Background Cancer stem-like traits contribute to prostate cancer (PCa) progression and metastasis. Deciphering the novel molecular mechanisms underlying stem-like traits may provide important insight for developing novel therapeutics. Methods Immunohistochemistry and immunofluorescence assays in prostatic tissues; gain- and loss-of-function analyses using ectopic overexpression and shRNAs in PCa cell lines; measurements of tumorigenic and stemness properties, and transcription in vitro and in vivo; transcriptional analysis in public databases. Results We identified that overexpression of BTF3 in PCa tissues and BTF3 expression highly correlates to stem-like traits. Cancer stem-like characteristics in PCa including self-renewal and metastatic potential were impaired by BTF3 loss and promoted by BTF3 overexpression. Mechanistically, BTF3 could stabilize BMI1, which is a crucial regulator of prostate stem cell self-renewal. More importantly, our data revealed that BTF3 is highly predictive of poor prognosis and may help in risk stratification of PCa patients. Conclusions BTF3 promotes PCa progression though modeling stem-like traits in PCa. BTF3 represents a stratification marker in PCa progression and outcomes

    MDP Up-Regulates the Gene Expression of Type I Interferons in Human Aortic Endothelial Cells

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    Muramyldipeptide (MDP), the minimum essential structure responsible for the immuno-adjuvant activity of peptidoglycan, is recognized by intracellular nuclear-binding oligomerization domain 2 (NOD2). Here, we obtained evidence that the treatment of human aortic endothelial cells (HAECs) with MDP up-regulated the gene expression of type I interferons in a dose- and time-dependent manner. MDP also up-regulated the expression of the receptor NOD2, suggesting that MDP may induce a positive feedback response. The up-regulation of interferons was not dependent on the TNFa signaling, as HAECs did not express TNFa with the stimulation of MDP, and TNFa neutralizing antibody did not decrease the induction of IFNs induced by MDP. RT-PCR results showed that HAECs expressed the gene transcripts of interferon regulatory factor (IRF) 1, 2, 3, 9. The western blot results showed that MDP induced the phosphorylation of IRF3. These results suggested that MDP induced the up-regulation of gene transcript of interferons through the activation of IRF3 signaling pathway. Meanwhile, MDP induced the gene expression of pro-inflammatory cytokines, including IL-1ß, IL-8, and MCP-1. Taken together, these results suggested that HAECs may play roles in the anti-infection immune response and in the induction of innate immunity
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