45 research outputs found

    Myloid cell-specific lipin-1 deficiency stimulates endocrine adiponectin-FGF15 axis and ameliorates ethanol-induced liver injury in mice

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    Lipin-1 is a phosphatidate phosphohydrolase (PAP) required for the generation of diacylglycerol during glycerolipid synthesis, and exhibits dual functions in the regulation of lipid metabolism. Lipin-1 has been implicated in the pathogenesis of alcoholic liver disease (ALD). In the present study, we assessed lipin-1 function in myeloid cells in ALD using a myeloid cell-specific lipin-1 knockout (mLipin-1KO) mouse model. Utilizing the Gao-binge ethanol feeding protocol, matched mLipin-1KO mice and littermate loxP control (WT) mice were pair-fed with either an ethanol-containing diet or an ethanol-free diet (control). Surprisingly, deletion of lipin-1 in myeloid cells dramatically attenuated liver inflammatory responses and ameliorated liver injury that would normally occur following the ethanol feeding protocol, but slightly exacerbated the ethanol-induced steatosis in mice. Mechanistically, myeloid cell-specific lipin-1 deficiency concomitantly increased the fat-derived adiponectin and ileum-derived fibroblast growth factor (FGF) 15. In concordance with concerted elevation of circulating adiponectin and FGF15, myeloid cell-specific lipin-1 deficiency diminished hepatic nuclear factor kappa B (NF-κB) activity, limited liver inflammatory responses, normalized serum levels of bile acids, and protected mice from liver damage after ethanol challenge. Our novel data demonstrate that myeloid cell-specific deletion of lipin-1 ameliorated inflammation and alcoholic hepatitis in mice via activation of endocrine adiponectin-FGF15 signaling

    Integrative Brain Transcriptome Analysis Reveals Region-Specific and Broad Molecular Changes in Shank3-Overexpressing Mice

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    Variants of the SH3 and multiple ankyrin repeat domain 3 (SHANK3) gene, encoding excitatory postsynaptic core scaffolding proteins, are causally associated with numerous neurodevelopmental and neuropsychiatric disorders, including autism spectrum disorder (ASD), bipolar disorder, intellectual disability, and schizophrenia (SCZ). Although detailed synaptic changes of various Shank3 mutant mice have been well characterized, broader downstream molecular changes, including direct and indirect changes, remain largely unknown. To address this issue, we performed a transcriptome analysis of the medial prefrontal cortex (mPFC) of adult Shank3-overexpressing transgenic (TG) mice, using an RNA-sequencing approach. We also re-analyzed previously reported RNA-sequencing results of the striatum of adult Shank3 TG mice and of the prefrontal cortex of juvenile Shank3+/ΔC mice with a 50–70% reduction of Shank3 proteins. We found that several myelin-related genes were significantly downregulated specifically in the mPFC, but not in the striatum or hippocampus, of adult Shank3 TG mice by comparing the differentially expressed genes (DEGs) of the analyses side by side. Moreover, we also found nine common DEGs between the mPFC and striatum of Shank3 TG mice, among which we further characterized ASD- and SCZ-associated G protein-coupled receptor 85 (Gpr85), encoding an orphan Gpr interacting with PSD-95. Unlike the mPFC-specific decrease of myelin-related genes, we found that the mRNA levels of Gpr85 increased in multiple brain regions of adult Shank3 TG mice, whereas the mRNA levels of its family members, Gpr27 and Gpr173, decreased in the cortex and striatum. Intriguingly, in cultured neurons, the mRNA levels of Gpr27, Gpr85, and Gpr173 were modulated by the neuronal activity. Furthermore, exogenously expressed GPR85 was co-localized with PSD-95 and Shank3 in cultured neurons and negatively regulated the number of excitatory synapses, suggesting its potential role in homeostatic regulation of excitatory synapses in Shank3 TG neurons. Finally, we performed a gene set enrichment analysis of the RNA-sequencing results, which suggested that Shank3 could affect the directional expression pattern of numerous ribosome-related genes in a dosage-dependent manner. To sum up, these results reveal previously unidentified brain region-specific and broad molecular changes in Shank3-overexpressing mice, further elucidating the complexity of the molecular pathophysiology of SHANK3-associated brain disorders

    Integrated Rocket Simulation of Internal and External Flow Dynamics in an e-Science Environment

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    The internal and external flowfield variation of a launch vehicle has been simulated in an e-Science environment. To analyze the igniting process of a solid-rocket propellant, a fluid-structure interaction code has been developed using an ALE (arbitrary Lagrangian Eulerian) kinematical description and a staggered fluid-structure interaction algorithm. Also, unsteady motion of a detached rocket booster has been predicted by using an external flow analysis with an aerodynamic-dynamic coupled solver. A Korean e-Science environment designed for aerospace engineering, e-AIRS [15], supplies a user-friendly interface for such individual work and it can advance to an integrated rocket simulation of internal combustion and external flow variation by controlling the execution and data flow of two flow solvers. As a consequence, e-Science facilitates multi-disciplinary collaborative research, and makes individual work more convenient.The current work is a product of the Korea National e-Science project. The authors are grateful to the Korea Institute of Science and Technology Information for their financial support. Also, the authors appreciate the financial supports provided by NSL(National Space Lab.) program through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology (Grant 20090091724) and the authors are grateful to the Agency for Defence Development for financial support on solid-rocket propellant research.OAIID:oai:osos.snu.ac.kr:snu2009-01/102/0000004648/4SEQ:4PERF_CD:SNU2009-01EVAL_ITEM_CD:102USER_ID:0000004648ADJUST_YN:YEMP_ID:A001138DEPT_CD:446CITE_RATE:1.2FILENAME:article.pdfDEPT_NM:기계항공공학부EMAIL:[email protected]_YN:YCONFIRM:

    Striatal Transcriptome and Interactome Analysis of Shank3-overexpressing Mice Reveals the Connectivity between Shank3 and mTORC1 Signaling

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    Mania causes symptoms of hyperactivity, impulsivity, elevated mood, reduced anxiety and decreased need for sleep, which suggests that the dysfunction of the striatum, a critical component of the brain motor and reward system, can be causally associated with mania. However, detailed molecular pathophysiology underlying the striatal dysfunction in mania remains largely unknown. In this study, we aimed to identify the molecular pathways showing alterations in the striatum of SH3 and multiple ankyrin repeat domains 3 (Shank3)-overexpressing transgenic (TG) mice that display manic-like behaviors. The results of transcriptome analysis suggested that mammalian target of rapamycin complex 1 (mTORC1) signaling may be the primary molecular signature altered in the Shank3 TG striatum. Indeed, we found that striatal mTORC1 activity, as measured by mTOR S2448 phosphorylation, was significantly decreased in the Shank3 TG mice compared to wild-type (WT) mice. To elucidate the potential underlying mechanism, we re-analyzed previously reported protein interactomes, and detected a high connectivity between Shank3 and several upstream regulators of mTORC1, such as tuberous sclerosis 1 (TSC1), TSC2 and Ras homolog enriched in striatum (Rhes), via 94 common interactors that we denominated “Shank3-mTORC1 interactome”. We noticed that, among the 94 common interactors, 11 proteins were related to actin filaments, the level of which was increased in the dorsal striatum of Shank3 TG mice. Furthermore, we could co-immunoprecipitate Shank3, Rhes and Wiskott-Aldrich syndrome protein family verprolin-homologous protein 1 (WAVE1) proteins from the striatal lysate of Shank3 TG mice. By comparing with the gene sets of psychiatric disorders, we also observed that the 94 proteins of Shank3-mTORC1 interactome were significantly associated with bipolar disorder (BD). Altogether, our results suggest a protein interaction-mediated connectivity between Shank3 and certain upstream regulators of mTORC1 that might contribute to the abnormal striatal mTORC1 activity and to the manic-like behaviors of Shank3 TG mice

    Altered presynaptic function and number of mitochondria in the medial prefrontal cortex of adult Cyfip2 heterozygous mice

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    Variants of the cytoplasmic FMR1-interacting protein (CYFIP) gene family, CYFIP1 and CYFIP2, are associated with numerous neurodevelopmental and neuropsychiatric disorders. According to several studies, CYFIP1 regulates the development and function of both pre- and post-synapses in neurons. Furthermore, various studies have evaluated CYFIP2 functions in the postsynaptic compartment, such as regulating dendritic spine morphology; however, no study has evaluated whether and how CYFIP2 affects presynaptic functions. To address this issue, in this study, we have focused on the presynapses of layer 5 neurons of the medial prefrontal cortex (mPFC) in adult Cyfip2 heterozygous (Cyfip2+/−) mice. Electrophysiological analyses revealed an enhancement in the presynaptic short-term plasticity induced by high-frequency stimuli in Cyfip2+/− neurons compared with wild-type neurons. Since presynaptic mitochondria play an important role in buffering presynaptic Ca2+, which is directly associated with the short-term plasticity, we analyzed presynaptic mitochondria using electron microscopic images of the mPFC. Compared with wild-type mice, the number, but not the volume or cristae density, of mitochondria in both presynaptic boutons and axonal processes in the mPFC layer 5 of Cyfip2+/− mice was reduced. Consistent with an identification of mitochondrial proteins in a previously established CYFIP2 interactome, CYFIP2 was detected in a biochemically enriched mitochondrial fraction of the mouse mPFC. Collectively, these results suggest roles for CYFIP2 in regulating presynaptic functions, which may involve presynaptic mitochondrial changes.This work was supported by the National Research Foundation of Korea (NRF) grants funded by the Korea Government Ministry of Science and ICT (NRF-2018R1C1B6001235, NRF-2018M3C7A1024603, NRF-2017M3C7A1048086, and NRF-2020R1A2C3011464) and the KBRI Basic Research Programs (20-BR01-08 and 20-BR-04-01)

    The novel RAGE interactor PRAK is associated with autophagy signaling in Alzheimer’s disease pathogenesis

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    BACKGROUND: The receptor for advanced glycation end products (RAGE) has been found to interact with amyloid β (Aβ). Although RAGE does not have any kinase motifs in its cytosolic domain, the interaction between RAGE and Aβ triggers multiple cellular signaling involved in Alzheimer’s disease (AD). However, the mechanism of signal transduction by RAGE remains still unknown. Therefore, identifying binding proteins of RAGE may provide novel therapeutic targets for AD. RESULTS: In this study, we identified p38-regulated/activated protein kinase (PRAK) as a novel RAGE interacting molecule. To investigate the effect of Aβ on PRAK mediated RAGE signaling pathway, we treated SH-SY5Y cells with monomeric form of Aβ. We demonstrated that Aβ significantly increased the phosphorylation of PRAK as well as the interaction between PRAK and RAGE. We showed that knockdown of PRAK rescued mTORC1 inactivation induced by Aβ treatment and decreased the formation of Aβ-induced autophagosome. CONCLUSIONS: We provide evidence that PRAK plays a critical role in AD pathology as a key interactor of RAGE. Thus, our data suggest that PRAK might be a potential therapeutic target of AD involved in RAGE-mediated cell signaling induced by Aβ. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13024-016-0068-5) contains supplementary material, which is available to authorized users

    Hybrid Multithreaded Architecture with Symmetric Multiprocessors

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    Multithreading is effective to solve latency and synchronization problems which are fundamental issues in parallel processing. One of multithreaded computers, DAVRID has the computational model which is based on dataflow model together with advantages of von Neumann model. In this paper, we introduce some problems of DAVRID through performance evaluation and propose new architecture, MSA(Hybrid Multithreaded Symmetric Multiprocessor Architecture). DAVRID effectively solves latency and synchronization problem in the view of computational model, but has difficulty in exploiting locality in the view of architecture. MSA pursuits efficient parallel processing in the way it inherits the computational model of DAVRID and has symmetric multiprocessor architecture. Simulation result shows that the execution time of MSA is remarkably reduced compared with that of DAVRID, and also high variance of utilization among units is reduced and overall utilization is increased. Keywords: multithreading,..

    Quantization-Aware Pruning Criterion for Industrial Applications

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    In this study, we propose a simple and effective quantization-aware neural network pruning method to prune and quantize deep neural networks and then run them on lightweight and cost-effective embedded industrial devices. The proposed pruning method provides a suitable pruning strategy for a given bit precision before performing the subsequent quantization. In particular, the dropout rate is set to be bounded below by the maximum number of quantization levels, which enables the regulation of the tradeoff between sparsity and performance loss. The Kullback-Leibler divergence term of the evidence lower bound is also weighted for adjusting the performance loss. From learned dropout rates, efficient bit allocation is provided to maintain randomness even through the quantization step. In supervised and reinforcement learning applications, the proposed quantization-aware pruning method was proven to be successful in obtaining sparse and lightweight neural networks while maintaining their performance even after quantization. In particular, a real inverted pendulum system was used to determine whether the proposed method works well for actual physical control systems.11Nsciescopu
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