17 research outputs found

    Overexpression of Tisochrysis lutea Akd1 identifies a key cold-induced alkenone desaturase enzyme

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    Alkenones are unusual long-chain neutral lipids that were first identified in oceanic sediments. Currently they are regarded as reliable palaeothermometers, since their unsaturation status changes depending on temperature. These molecules are synthesised by specific haptophyte algae and are stored in the lipid body as the main energy storage molecules. However, the molecular mechanisms that regulate the alkenone biosynthetic pathway, especially the low temperature-dependent desaturation reaction, have not been elucidated. Here, using an alkenone-producing haptophyte alga, Tisochrysis lutea, we show that the alkenone desaturation reaction is catalysed by a newly identified desaturase. We first isolated two candidate desaturase genes and found that one of these genes was drastically upregulated in response to cold stress. Gas chromatographic analysis revealed that the overexpression of this gene, named as Akd1 finally, increased the conversion of di-unsaturated C37-alkenone to tri-unsaturated molecule by alkenone desaturation, even at a high temperature when endogenous desaturation is efficiently suppressed. We anticipate that the Akd1 gene will be of great help for elucidating more detailed mechanisms of temperature response of alkenone desaturation, and identification of active species contributing alkenone production in metagenomic and/or metatranscriptomic studies in the field of oceanic biogeochemistry

    Biomass production and nutrient removal by spontaneous grown green algae oedogonium sp. from a pond in University of Tsukuba

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    As one of the methods for nutrient removal from eutrophicated lakes and ponds affected by nonpoint nutrient pollution, the conversion of nutrients into aquatic plant biomass (APB) has drawn increasing attention. In this study, the acquisition and sequestration of nutrients by APB and the application of APB as a resource were discussed. The study site was an eutrophicated inland pond at the University of Tsukuba, Amano-Gawa, which is occasionally covered with the submerged macrophyte green alga Oedogonium sp. This species was found to produce 1048 kg of total biomass in dry weight and 13.1 kg of lipid per harvest

    Targeting miR-223 in neutrophils enhances the clearance of Staphylococcus aureus in infected wounds

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    Abstract Argonaute 2 bound mature microRNA (Ago2‐miRNA) complexes are key regulators of the wound inflammatory response and function in the translational processing of target mRNAs. In this study, we identified four wound inflammation‐related Ago2‐miRNAs (miR‐139‐5p, miR‐142‐3p, miR‐142‐5p, and miR‐223) and show that miR‐223 is critical for infection control. miR‐223Y/− mice exhibited delayed sterile healing with prolonged neutrophil activation and interleukin‐6 expression, and markedly improved repair of Staphylococcus aureus‐infected wounds. We also showed that the expression of miR‐223 was regulated by CCAAT/enhancer binding protein alpha in human neutrophils after exposure to S. aureus peptides. Treatment with miR‐223Y/−‐derived neutrophils, or miR‐223 antisense oligodeoxynucleotides in S. aureus‐infected wild‐type wounds markedly improved the healing of these otherwise chronic, slow healing wounds. This study reveals how miR‐223 regulates the bactericidal capacity of neutrophils at wound sites and indicates that targeting miR‐223 might be of therapeutic benefit for infected wounds in the clinic

    Publisher Correction: Genetic tool development in marine protists: emerging model organisms for experimental cell biology.

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    An amendment to this paper has been published and can be accessed via a link at the top of the paper

    Genetic tool development in marine protists: emerging model organisms for experimental cell biology

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    Abstract: Diverse microbial ecosystems underpin life in the sea. Among these microbes are many unicellular eukaryotes that span the diversity of the eukaryotic tree of life. However, genetic tractability has been limited to a few species, which do not represent eukaryotic diversity or environmentally relevant taxa. Here, we report on the development of genetic tools in a range of protists primarily from marine environments. We present evidence for foreign DNA delivery and expression in 13 species never before transformed and for advancement of tools for eight other species, as well as potential reasons for why transformation of yet another 17 species tested was not achieved. Our resource in genetic manipulation will provide insights into the ancestral eukaryotic lifeforms, general eukaryote cell biology, protein diversification and the evolution of cellular pathways

    Efficacy and safety of a novel pain management device, AT-04, for endometriosis-related pain: study protocol for a phase III randomized controlled trial

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    Abstract Background Endometriosis-related pain encompassing dysmenorrhea, dyspareunia, and chronic pelvic pain, reduces the quality of life in premenopausal women. Although treatment options for endometriosis alleviate this pain, approximately one-third of women still experience pain even after receiving treatment, indicating the need for novel approaches to pain relief in those women. The Angel Touch device (AT-04) is a portable magnetic fields irradiation device that incorporates a combination of mixed alternative magnetic fields at 2 kHz and 83.3 MHz. A phase III trial confirmed the efficacy and safety of AT-02, a prototype of AT-04, for pain relief in patients with fibromyalgia. Methods This is a phase III, multicenter, prospective, randomized, sham device-controlled, double-blind, parallel study. The participants will be premenopausal women aged > 18 years who have endometriosis-related pain with at least moderate severity. Considering dropouts, 50 participants have been deemed appropriate. Eligible women will be centrally registered, and the data center will randomly allocate them in a 1:1 ratio to the intervention and control groups. Women in the intervention group will receive electromagnetic wave irradiation generated by AT-04 and those who in the control group will wear a sham device for 16 weeks, and both groups will wear AT-04 for another 4 weeks. The primary outcome measure is the change in the Numeric Rating Scale score at 16 weeks compared with the baseline. Secondary outcome measures are efficacy for pelvic pain including dysmenorrhea and non-menstrual pain, and chronic pelvic pain not related to menstruation, dysmenorrhea, and dyspareunia, and improvement of quality of life during the study period. Safety will be evaluated by device defects and the frequency of adverse events. The study protocol has been approved by the Clinical Study Review Board of Chiba University Hospital, Chiba, Japan, and will be conducted in accordance with the principles of the Declaration of Helsinki and the Japanese Clinical Trials Act and relevant notifications. Discussion This study aims to develop a novel method of managing endometriosis-related pain. The AT-04 is an ultralow-invasive device that can be used without inhibiting ovulation, suggesting potential benefits to women of reproductive-age. Trial registration number Japan Registry of Clinical Trials (jRCTs032230278)
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