24 research outputs found

    Cytotoxic Polyketides with an Oxygen-Bridged Cyclooctadiene Core Skeleton from the Mangrove Endophytic Fungus \u3ci\u3ePhomosis\u3c/i\u3e sp. A818

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    Plant endophytic microorganisms represent a largely untapped resource for new bioactive natural products. Eight polyketide natural products were isolated from a mangrove endophytic fungus Phomosis sp. A818. The structural elucidation of these compounds revealed that they share a distinct feature in their chemical structures, an oxygen-bridged cyclooctadiene core skeleton. The study on their structure–activity relationship showed that the α,β-unsaturated δ-lactone moiety, as exemplified in compounds 1 and 2, was critical to the cytotoxic activity of these compounds. In addition, compound 4 might be a potential agonist of AMPK (5\u27-adenosine monophosphate-activated protein kinase)

    H2AX Deficiency is Associated with Erythroid Dysplasia and Compromised Haematopoietic Stem Cell Function

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    Myelodysplastic syndromes (MDS) are clonal disorders of haematopoiesis characterised by dysplastic changes of major myeloid cell lines. However, the mechanisms underlying these dysplastic changes are poorly understood. Here, we used a genetically modified mouse model and human patient data to examine the physiological roles of H2AX in haematopoiesis and how the loss of H2AX contributes to dyserythropoiesis in MDS. H2AX knockout mice showed cell-autonomous anaemia and erythroid dysplasia, mimicking dyserythropoiesis in MDS. Also, dyserythropoiesis was increased in MDS patients with the deletion of chromosome 11q23, where H2AX is located. Although loss of H2AX did not affect the early stage of terminal erythropoiesis, enucleation was decreased. H2AX deficiency also led to the loss of quiescence of hematopoietic stem and progenitor cells, which dramatically compromised their bone marrow engraftment. These results reveal important roles of H2AX in late-stage terminal erythropoiesis and hematopoietic stem cell function

    Inhibition of the m6A reader IGF2BP2 as a strategy against T-cell acute lymphoblastic leukemia

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    T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignant leukemia with extremely limited treatment for relapsed patients. N6‐methyladenosine (m6A) reader insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) participates in the initiation and growth of cancers by communicating with various targets. Here, we found IGF2BP2 was highly expressed in T-ALL. Gain and loss of IGF2BP2 demonstrated IGF2BP2 was essential for T-ALL cell proliferation in vitro and loss of IGF2BP2 prolonged animal survival in a human T-ALL xenograft model. Mechanistically, IGF2BP2 directly bound to T-ALL oncogene NOTCH1 via an m6A dependent manner. Furthermore, we identified a small-molecule IGF2BP2 inhibitor JX5 and treatment of T-ALL with JX5 showed similar functions as knockdown of IGF2BP2. These findings not only shed light on the role of IGF2BP2 in T-ALL, but also provide an alternative γ‑Secretase inhibitors (GSI) therapy to treat T-ALL.Inhibition of the m6A reader IGF2BP2 as a strategy against T-cell acute lymphoblastic leukemiapublishedVersio

    Molecular Packing Control Enables Excellent Performance and Mechanical Property of Blade-Cast All-Polymer Solar Cells

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    All-polymer solar cells (all-PSCs) are the most promising power generators for flexible and portable devices due to excellent morphology stability and outstanding mechanical property. Previous work indicates high crystallinity is beneficial to device performance but detrimental to mechanical property, therefore identifying the optimized ratio between crystalline and amorphous domains becomes important. In this work, we demonstrated highly efficient and mechanically robust all-PSCs by blade-coating technology in ambient environment based on PTzBI:N2200 system. By controlling the aggregation in solution state and ultrafast film formation process, a weakly ordered molecular packing morphology as well as small phase separation is obtained, which leads to not only the good photovoltaic performance (8.36%-one of the best blade-cast device in air) but also prominent mechanical characteristic. The controlled film shows a remarkable elongation with the crack onset strain of 15.6%, which is the highest result in organic solar cells without adding elastomers. These observations indicate the great promise of the developed all-PSCs for practical applications toward large-area processing technology

    Cytotoxic Polyketides with an Oxygen-Bridged Cyclooctadiene Core Skeleton from the Mangrove Endophytic Fungus \u3ci\u3ePhomosis\u3c/i\u3e sp. A818

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    Plant endophytic microorganisms represent a largely untapped resource for new bioactive natural products. Eight polyketide natural products were isolated from a mangrove endophytic fungus Phomosis sp. A818. The structural elucidation of these compounds revealed that they share a distinct feature in their chemical structures, an oxygen-bridged cyclooctadiene core skeleton. The study on their structure–activity relationship showed that the α,β-unsaturated δ-lactone moiety, as exemplified in compounds 1 and 2, was critical to the cytotoxic activity of these compounds. In addition, compound 4 might be a potential agonist of AMPK (5\u27-adenosine monophosphate-activated protein kinase)

    Cytotoxic Polyketides with an Oxygen-Bridged Cyclooctadiene Core Skeleton from the Mangrove Endophytic Fungus Phomosis sp. A818

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    Plant endophytic microorganisms represent a largely untapped resource for new bioactive natural products. Eight polyketide natural products were isolated from a mangrove endophytic fungus Phomosis sp. A818. The structural elucidation of these compounds revealed that they share a distinct feature in their chemical structures, an oxygen-bridged cyclooctadiene core skeleton. The study on their structure–activity relationship showed that the α,β-unsaturated δ-lactone moiety, as exemplified in compounds 1 and 2, was critical to the cytotoxic activity of these compounds. In addition, compound 4 might be a potential agonist of AMPK (5′-adenosine monophosphate-activated protein kinase)
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