17 research outputs found

    Absence of Appl2 sensitizes endotoxin shock through activation of PI3K/Akt pathway

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    BACKGROUND: The adapter proteins Appl1 (adaptor protein containing pleckstrin homology domain, phosphotyrosine domain, and leucine zipper motif 1) and Appl2 are highly homologous and involved in several signaling pathways. While previous studies have shown that Appl1 plays a pivotal role in adiponectin signaling and insulin secretion, the physiological functions of Appl2 are largely unknown. RESULTS: In the present study, the role of Appl2 in sepsis shock was investigated by using Appl2 knockout (KO) mice. When challenged with lipopolysaccharides (LPS), Appl2 KO mice exhibited more severe symptoms of endotoxin shock, accompanied by increased production of proinflammatory cytokines. In comparison with the wild-type control, deletion of Appl2 led to higher levels of TNF-α and IL-1β in primary macrophages. In addition, phosphorylation of Akt and its downstream effector NF-κB was significantly enhanced. By co-immunoprecipitation, we found that Appl2 and Appl1 interacted with each other and formed a complex with PI3K regulatory subunit p85α, which is an upstream regulator of Akt. Consistent with these results, deletion of Appl1 in macrophages exhibited characteristics of reduced Akt activation and decreased the production of TNFα and IL-1β when challenged by LPS. CONCLUSIONS: Results of the present study demonstrated that Appl2 is a critical negative regulator of innate immune response via inhibition of PI3K/Akt/NF-κB signaling pathway by forming a complex with Appl1 and PI3K.published_or_final_versio

    Harmine Induces Adipocyte Thermogenesis through RAC1-MEK-ERK-CHD4 Axis

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    © The Author(s) 2016.Harmine is a natural compound possessing insulin-sensitizing effect in db/db diabetic mice. However its effect on adipose tissue browning is unknown. Here we reveal that harmine antagonizes high fat diet-induced adiposity. Harmine-treated mice gained less weight on a high fat diet and displayed increased energy expenditure and adipose tissue thermogenesis. In vitro, harmine potently induced the expression of thermogenic genes in both brown and white adipocytes, which was largely abolished by inhibition of RAC1/MEK/ERK pathway. Post-transcriptional modification analysis revealed that chromodomain helicase DNA binding protein 4 (CHD4) is a potential downstream target of harmine-mediated ERK activation. CHD4 directly binds the proximal promoter region of Ucp1, which is displaced upon treatment of harmine, thereby serving as a negative modulator of Ucp1. Thus, here we reveal a new application of harmine in combating obesity via this off-target effect in adipocytes.published_or_final_versio

    GNER: A Generative Model for Geological Named Entity Recognition Without Labeled Data Using Deep Learning

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    Abstract A variety of detailed data about geological topics and geoscience knowledge are buried in the geoscience literature and rarely used. Named entity recognition (NER) provides both opportunities and challenges to leverage this wealth of data in the geoscience literature for data analysis and further information extraction. Existing NER models and techniques are mainly based on rule‐based and supervised approaches, and developing such systems requires a costly manual effort. In this paper, we first design a generic stepwise framework for domain‐specific NER. Following this framework, domain‐specific entities and domain‐general words are collected and selected as seed terms. Normalization and grouping processes are then applied to these seed terms for further analysis. A random extraction algorithm based on a unigram language model is used to generate a large‐scale training data set consisting of probabilistically labeled pseudosentences. Each generated sentence is then used as input to the self‐training and learning algorithm. Experimental results on two constructed data sets demonstrate that the proposed model effectively recognizes and identifies geological named entities

    Comparative Analysis of Protein Digestion Characteristics in Human, Cow, Goat, Sheep, Mare, and Camel Milk under Simulated Infant Condition

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    An infant in vitro digestion model was utilized to investigate protein digestion characteristics in human and diverse mammalian milk (i.e., cow, goat, sheep, mare, and camel milk) using electrophoresis and chromatography. Digestive differences among milks were mainly manifested in the infant gastric phase, as evidenced by varying degrees of protein digestion. Notably, proteins (i.e., lactoferrin, serum albumin, and immunoglobulin G-heavy chain) remained partially intact in human milk, whereas these proteins in animal milk were exclusively degraded after gastrointestinal digestion. The peptide spectra of human, mare, and camel milk were highly similar, with a predominant formation of low-intensity small peptides, whereas the other three milk showed the opposite phenomenon. Heatmap cluster analysis indicated that camel milk was the most comparable to human milk before digestion, yet sheep milk was the most similar to human milk regarding protein digestion behaviors following infant gastric digestion

    Conversion of non-adipogenic fibroblasts into adipocytes by a defined hormone mixture

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    © The Authors Journal compilation © 2015 Biochemical Society.Obesity is accompanied by an increase in the size and the number of adipocytes. As adipocytes are thought to differentiate from pre-adipocytes, we postulate that non-adipogenic fibroblasts contribute to adipocyte formation under certain conditions such as obesity. We report for the first time that NIH-3T3 fibroblasts, which are generally considered to be non-adipogenic, can be converted into mature adipocytes by treatment with a defined hormone mixture comprising EGF (epidermal growth factor), HGF (hepatocyte growth factor), Dex (dexamethasone) and insulin. Furthermore, NIH-3T3 cells transplanted into obese immunodeficient NOD/SCID (non-obese diabetic/severe combined immunodeficient) mice formed adipocytes in vivo. Interestingly, the mixture elicited conversion of NIH-3T3 cells directly into adipocytes without a preceding pre-adipocyte stage. Functional analysis revealed that each component of the mixture was necessary for the induction of adipogenesis, including Dex which inhibited the cell proliferation stimulated by EGF. Upon profiling the signalling pathways employed by EGF and HGF, we found STAT5 (signal transducer and activator of transcription 5) signalling to be activated, predominantly at the levels of both transcription and post-translational modification. Inhibition of the STAT5 pathway, either by genetic knockdown or a specific pharmacological agent, blocked adipogenesis in NIH-3T3 cells. Taken together, these data not only establish a newly recognized grouping of factors that can induce trans-differentiation of nonadipogenic fibroblasts into adipocytes, but also give us a greater understanding of obesity.Link_to_subscribed_fulltex

    Brown Adipogenic Reprogramming Induced by a Small Molecule

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    Brown adipose tissue (BAT) has attracted considerable research interest because of its therapeutic potential to treat obesity and associated metabolic diseases. Augmentation of brown fat mass and/or its function may represent an attractive strategy to enhance energy expenditure. Using high-throughput phenotypic screening to induce brown adipocyte reprogramming in committed myoblasts, we identified a retinoid X receptor (RXR) agonist, bexarotene (Bex), that efficiently converted myoblasts into brown adipocyte-like cells. Bex-treated mice exhibited enlarged BAT mass, enhanced BAT function, and a modest browning effect in subcutaneous white adipose tissue (WAT). Expression analysis showed that Bex initiated several “browning” pathways at an early stage during brown adipocyte reprogramming. Our findings suggest RXRs as new master regulators that control brown and beige fat development and activation, unlike the common adipogenic regulator PPARγ. Moreover, we demonstrated that selective RXR activation may potentially offer a therapeutic approach to manipulate brown/beige fat function in vivo

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    The natural compound, formononetin, extracted from Astragalus membranaceus increases adipocyte thermogenesis by modulating PPAR gamma activity

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    BACKGROUND AND PURPOSE Increasing energy expenditure through adipocyte thermogenesis is generally accepted as a promising strategy to mitigate obesity and its related diseases. However, few clinically effective and safe agents are known to promote adipocyte thermogenesis. In this study, 20 traditional Chinese herbal medicines were screened to examine whether they induced adipocyte thermogenesis. EXPERIMENTAL APPROACH The effects of Chinese herbal medicines or components isolated from extracts of A. membranaceus, on adipocyte thermogenesis were analysed by assessing expression of uncoupling protein 1 (UCP1) by qPCR. Eight-week-old C57BL6/J male mice were fed a high-fat diet for 8 weeks and then randomized to two groups treated with vehicle or formononetin for another 8 weeks. Glucose tolerance tests and staining of adipose tissue with haematoxylin and eosin were carried out. Whole-body oxygen consumption was measured with an open-circuit indirect calorimetry system. KEY RESULTS Extracts of A. membranaceus increased expression of Ucp1 in primary cultures of mouse adipocytes. Formononetin was the only known component of A. membranaceus extracts to increase adipocyte Ucp1 expression. Diet-induced obese mice treated with formononetin gained less weight and showed higher energy expenditure than untreated mice. In addition, formononetin binds directly with PPAR gamma. CONCLUSIONS AND IMPLICATION Taken together, our study demonstrates that the Chinese herbal medicine from A. membranaceus and its constituent formononetin have the potential to reduce obesity and associated metabolic disorders. Our results suggest that formononetin regulates adipocyte thermogenesis as a non-classical PPAR gamma agonist
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