180 research outputs found

    AMPK-Dependent Metabolic Regulation by PPAR Agonists

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    Comprehensive studies support the notion that the peroxisome proliferator-activated receptors, (PPARs), PPARα, PPARβ/δ, and PPARγ, regulate cell growth, morphogenesis, differentiation, and homeostasis. Agonists of each PPAR subtype exert their effects similarly or distinctly in different tissues such as liver, muscle, fat, and vessels. It is noteworthy that PPARα or PPARγ agonists have pharmacological effects by modulating the activity of AMPK, which is a key cellular energy sensor. However, the role of AMPK in the metabolic effects of PPAR agonists has not been thoroughly focused. Moreover, AMPK activation by PPAR agonists seems to be independent of the receptor activation. This intriguing action of PPAR agonists may account in part for the mechanistic basis of the therapeutics in the treatment of metabolic disease. In this paper, the effects of PPAR agonists on metabolic functions were summarized with particular reference to their AMPK activity regulation

    Consecutive Junction-Induced Efficient Charge Separation Mechanisms for High-Performance MoS2/Quantum Dot Phototransistors.

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    Phototransistors that are based on a hybrid vertical heterojunction structure of two-dimensional (2D)/quantum dots (QDs) have recently attracted attention as a promising device architecture for enhancing the quantum efficiency of photodetectors. However, to optimize the device structure to allow for more efficient charge separation and transfer to the electrodes, a better understanding of the photophysical mechanisms that take place in these architectures is required. Here, we employ a novel concept involving the modulation of the built-in potential within the QD layers for creating a new hybrid MoS2/PbS QDs phototransistor with consecutive type II junctions. The effects of the built-in potential across the depletion region near the type II junction interface in the QD layers are found to improve the photoresponse as well as decrease the response times to 950 μs, which is the faster response time (by orders of magnitude) than that recorded for previously reported 2D/QD phototransistors. Also, by implementing an electric-field modulation of the MoS2 channel, our experimental results reveal that the detectivity can be as large as 1 × 1011 jones. This work demonstrates an important pathway toward designing hybrid phototransistors and mixed-dimensional van der Waals heterostructures.The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007−2013)/ERC Grant Agreement no. 340538. This work was also supported by the National Research Foundation of Korea (NRF) (2015M2A2A6A02045252) and Samsung Global Research Outreach (Samsung GRO) program. In addition, S.M.M. would like to thank The Royal Society for financial support

    Therapeutic genome editing for Charcot-marie-tooth disease type 1a

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    Charcot-Marie-Tooth 1A (CMT1A) is the most common inherited neuropathy without a known therapy, which is caused by a 1.4 Mb duplication on human chromosome 17, which includes the gene encoding the peripheral myelin protein of 22 kDa (PMP22). Overexpressed PMP22 protein from its gene duplication is thought to cause demyelination and subsequently axonal degeneration in the peripheral nervous system (PNS). Here, we targeted regulatory region of human PMP22 to normalize overexpressed PMP22 level in C22 mice, a mouse model of CMT1A harboring multi copies of human PMP22. Direct local intraneural delivery of CRISPR/Cas9 designed to target TATA-box of PMP22 before the onset of disease, downregulates gene expression of PMP22 and preserves both myelin and axons. Notably, the same approach was effective in partial rescue of demyelination even after the onset of disease. Collectively, our data present a potential therapeutic efficacy of CRISPR/Cas9-mediated targeting of regulatory region of PMP22 to treat CMT1A. Please click Additional Files below to see the full abstract

    LONP1 and ClpP cooperatively regulate mitochondrial proteostasis for cancer cell survival

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    Mitochondrial proteases are key components in mitochondrial stress responses that maintain proteostasis and mitochondrial integrity in harsh environmental conditions, which leads to the acquisition of aggressive phenotypes, including chemoresistance and metastasis. However, the molecular mechanisms and exact role of mitochondrial proteases in cancer remain largely unexplored. Here, we identified functional crosstalk between LONP1 and ClpP, which are two mitochondrial matrix proteases that cooperate to attenuate proteotoxic stress and protect mitochondrial functions for cancer cell survival. LONP1 and ClpP genes closely localized on chromosome 19 and were co-expressed at high levels in most human cancers. Depletion of both genes synergistically attenuated cancer cell growth and induced cell death due to impaired mitochondrial functions and increased oxidative stress. Using mitochondrial matrix proteomic analysis with an engineered peroxidase (APEX)-mediated proximity biotinylation method, we identified the specific target substrates of these proteases, which were crucial components of mitochondrial functions, including oxidative phosphorylation, the TCA cycle, and amino acid and lipid metabolism. Furthermore, we found that LONP1 and ClpP shared many substrates, including serine hydroxymethyltransferase 2 (SHMT2). Inhibition of both LONP1 and ClpP additively increased the amount of unfolded SHMT2 protein and enhanced sensitivity to SHMT2 inhibitor, resulting in significantly reduced cell growth and increased cell death under metabolic stress. Additionally, prostate cancer patients with higher LONP1 and ClpP expression exhibited poorer survival. These results suggest that interventions targeting the mitochondrial proteostasis network via LONP1 and ClpP could be potential therapeutic strategies for cancer

    Effect of heat treatment and drawing on high-manganese steel pipe welded by gas tungsten arc

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    This study investigated the effect of post-weld processes including annealing and drawing on the microstructure and mechanical properties of high-Mn steel pipes welded by gas tungsten arc welding. The weld metal showed a solidified microstructure having coarse and elongated grains due to coalescence of columnar dendrite into welding heat direction. After post-annealing, the solidified microstructure changed into equiaxed grains due to recrystallization and grain growth. Mn segregation occurred during welding solidification and caused lower stacking fault energy (SFE) in the Mn-depleted region. Although epsilon-martensite formation in the as-welded state and during deformation was expected due to decreased SFE of the Mn-depleted zone, all regions showed a fully austenitic phase. The annealing process decreased strength due to grain coarsening but increased ductility. The drawing process increased strength of weld metal through work hardening. All pipes showed decreasing strain rate sensitivity (SRS) with deformation and negative SRS after certain strain levels. It was confirmed that negative SRS is related to less formation of mechanical twinning at a higher strain rate. This work provides fundamental insights into manufacturing a high-Mn steel pipe and manipulating its properties with annealing and drawing processes

    Genomic profile analysis of diffuse-type gastric cancers

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    Background: Stomach cancer is the third deadliest among all cancers worldwide. Although incidence of the intestinal-type gastric cancer has decreased, the incidence of diffuse-type is still increasing and its progression is notoriously aggressive. There is insufficient information on genome variations of diffuse-type gastric cancer because its cells are usually mixed with normal cells, and this low cellularity has made it difficult to analyze the genome. Results: We analyze whole genomes and corresponding exomes of diffuse-type gastric cancer, using matched tumor and normal samples from 14 diffuse-type and five intestinal-type gastric cancer patients. Somatic variations found in the diffuse-type gastric cancer are compared to those of the intestinal-type and to previously reported variants. We determine the average exonic somatic mutation rate of the two types. We find associated candidate driver genes, and identify seven novel somatic mutations in CDH1, which is a well-known gastric cancer-associated gene. Three-dimensional structure analysis of the mutated E-cadherin protein suggests that these new somatic mutations could cause significant functional perturbations of critical calcium-binding sites in the EC1-2 junction. Chromosomal instability analysis shows that the MDM2 gene is amplified. After thorough structural analysis, a novel fusion gene TSC2-RNF216 is identified, which may simultaneously disrupt tumor-suppressive pathways and activate tumorigenesis. Conclusions: We report the genomic profile of diffuse-type gastric cancers including new somatic variations, a novel fusion gene, and amplification and deletion of certain chromosomal regions that contain oncogenes and tumor suppressors.open121

    Truly form-factor–free industrially scalable system integration for electronic textile architectures with multifunctional fiber devices

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    Funding Information: This work was supported by the European Commission (H2020, 1D-NEON, grant agreement ID: 685758). J.M.K. and L.G.O. acknowledge the support from the U.K. Research and Innovation (EPSRC, EP/P027628/1). We thank Y. Bernstein and J. Faulkner for helping with grammar check. Funding Information: Acknowledgments Funding:ThisworkwassupportedbytheEuropeanCommission(H2020,1D-NEON,grant agreementID:685758).J.M.K.andL.G.O.acknowledgethesupportfromtheU.K.Researchand Innovation(EPSRC,EP/P027628/1).W ethankY .BernsteinandJ.Faulknerforhelpingwith grammarcheck.Authorcontributions:S.L.andJ.M.K.conceivedtheproject.S.L.,L.G.O.,P .B., R.Martins,andJ.M.K.supervisedtheproject.S.L.andH.L.developedF-PD.S.L.,Y .-W .L., G.-H.A., D.-W .S., J.I.S.,andS.C.developedF-SC.C.L.F ., A.S.,R.I.,P .B., andR.Martinsdevelopedfiber transistor.S.L.,H.L.,andS.C.developedF-LED.ThefiberdeviceswereevaluatedbyS.L.,H.W .C., D.-W .S., H.L.,S.J.,S.D.H.,S.Y .B., S.Z.,W .H.-C., Y .-H.S., X.-B.F ., T .H.L., J.-W .J., andY .K. The developmentofweavingprocesswasconductedbyS.L.,H.W .C., F .M.M., P .J., andV .G.C. Thelaser interconnectionwasdevelopedbyS.L.,H.W .C., K.U.,M.E.,andM.S.Thetextiledemonstrations werecharacterizedbyS.L.,H.W .C., D.-W .S., J.Y ., S.S.,U.E.,S.N.,A.C.,A.M.,R.Momentè,J.G.,N.D., S.M.,C.-H.K.,M.L.,A.N.,D.J.,M.C.,andY .C. ThismanuscriptwaswrittenbyS.L.andJ.M.K.and reviewed by H.W .C., D.-W .S., M.C.,L.G.O., P .B., E.F ., and G.A.J.A. All authors discussed the results andcommentedonthemanuscript.Competinginterests:Theauthorsdeclarethattheyhave nocompetinginterests.Dataandmaterialsavailability:Alldataneededtoevaluatethe conclusionsinthepaperarepresentinthepaperand/ortheSupplementaryMaterials. Publisher Copyright: Copyright © 2023 The Authors, some rights reserved.An integrated textile electronic system is reported here, enabling a truly free form factor system via textile manufacturing integration of fiber-based electronic components. Intelligent and smart systems require freedom of form factor, unrestricted design, and unlimited scale. Initial attempts to develop conductive fibers and textile electronics failed to achieve reliable integration and performance required for industrial-scale manufacturing of technical textiles by standard weaving technologies. Here, we present a textile electronic system with functional one-dimensional devices, including fiber photodetectors (as an input device), fiber supercapacitors (as an energy storage device), fiber field-effect transistors (as an electronic driving device), and fiber quantum dot light-emitting diodes (as an output device). As a proof of concept applicable to smart homes, a textile electronic system composed of multiple functional fiber components is demonstrated, enabling luminance modulation and letter indication depending on sunlight intensity.publishersversionpublishe
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