77 research outputs found

    SIRT2 regulates macrophage chemotaxis by de-modifying histone H4K8 lactylation

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    Objective·To explore the regulatory role of silent information regulator 2 (SIRT2) in modulating the immune phenotype of macrophages after infection by removing the lactylation at H4K8 site of histone and the corresponding mechanism.Methods·Human THP-1 leukemia cells were induced by phorbol 12-myristate 13-acetate (PMA) and stimulated by lipopolysaccharide (LPS) to establish a macrophage infection model. Macrophages without LPS treatment (pTHP-1) were set as the control (CTRL) group, and macrophages with LPS treatment were set as the infected (LPS) group. Western blotting was used to detect the level of histone modification and SIRT2 protein in macrophages. RT-qPCR was used to detect the expression level of glycolytic key enzymes [phosphofructokinase liver type (PFKL), lactate dehydrogenase A (LDHA)] and modulators genes hypoxia inducible factor 1α (HIF-1α), and the expression level of Sirtuin genes and HDAC genes between the two groups. Transwell was used to detect the ability of macrophage chemotaxis. Lentivirus packaging and cell infection were used to construct SIRT2 overexpression cell line. The interaction analysis method of RNA sequencing (RNA-seq) and chromatin immunoprecipitation sequencing (ChIP-seq) was used to analyze the difference and pathway enrichment of the genes specifically bound to H4K8 lactylation (H4K8la).Results·Compared to the CTRL group, macrophage glycolysis was upregulated and the level of H4K8la was significantly increased in the LPS group (P0.05). The interactive analysis of ChIP-seq and RNA-seq revealed that chemotaxis-related genes were regulated by H4K8la, and macrophage chemotaxis ability significantly decreased after the overexpression of SIRT2 and downregulation of H4K8la (P<0.05).Conclusion·SIRT2 can change the expression of target genes related to chemotaxis by removing H4K8la modification, thereby reducing the chemotaxis ability of macrophages. Targeting SIRT2 and H4K8la modification may help control inflammation mediated by macrophages

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Dark, Beyond Deep: A Paradigm Shift to Cognitive AI with Humanlike Common Sense

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    Recent progress in deep learning is essentially based on a "big data for small tasks" paradigm, under which massive amounts of data are used to train a classifier for a single narrow task. In this paper, we call for a shift that flips this paradigm upside down. Specifically, we propose a "small data for big tasks" paradigm, wherein a single artificial intelligence (AI) system is challenged to develop "common sense", enabling it to solve a wide range of tasks with little training data. We illustrate the potential power of this new paradigm by reviewing models of common sense that synthesize recent breakthroughs in both machine and human vision. We identify functionality, physics, intent, causality, and utility (FPICU) as the five core domains of cognitive AI with humanlike common sense. When taken as a unified concept, FPICU is concerned with the questions of "why" and "how", beyond the dominant "what" and "where" framework for understanding vision. They are invisible in terms of pixels but nevertheless drive the creation, maintenance, and development of visual scenes. We therefore coin them the "dark matter" of vision. Just as our universe cannot be understood by merely studying observable matter, we argue that vision cannot be understood without studying FPICU. We demonstrate the power of this perspective to develop cognitive AI systems with humanlike common sense by showing how to observe and apply FPICU with little training data to solve a wide range of challenging tasks, including tool use, planning, utility inference, and social learning. In summary, we argue that the next generation of AI must embrace "dark" humanlike common sense for solving novel tasks.Comment: For high quality figures, please refer to http://wellyzhang.github.io/attach/dark.pd

    Recent insights into targeting the IL-6 cytokine family in inflammatory diseases and cancer

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    The IL-6 family of cytokines consists of IL-6, IL-11, IL-27, IL-31, oncostatin M (OSM), leukaemia inhibitory factor (LIF), ciliary neurotrophic factor (CNTF), cardiotrophin 1 (CT-1) and cardiotrophin-like cytokine factor 1 (CLCF1). Membership of this cytokine family is defined by usage of common β-receptor signalling subunits, which activate various intracellular signalling pathways. Each IL-6 family member elicits responses essential to the physiological control of immune homeostasis, haematopoiesis, inflammation, development and metabolism. Accordingly, distortion of these cytokine activities often promotes chronic disease and cancer; the pathological importance of this is exemplified by the successful treatment of certain autoimmune conditions with drugs that target the IL-6 pathway. Here, we discuss the emerging roles for IL-6 family members in infection, chronic inflammation, autoimmunity and cancer and review therapeutic strategies designed to manipulate these cytokines in disease
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