8 research outputs found

    Possible Futures for Lean Construction: A Scenario Analysis for Germany

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    Lean construction is increasingly adopted due to low productivity, industry fragmentation, and adversarial relationships, enhancing stability and transparency. This paper outlines future scenarios for Germany, aiding construction companies in proactive preparation. Using the scenario technique, three Lean construction scenarios were developed and compared with AIgenerated results. A literature review examined Lean construction\u27s current state, followed by identifying crucial influencing factors through megatrend analysis and a PESTEL analysis. Sustainability, digitization, and collaboration emerged as key factors. Future projections for each were developed and linked to form scenarios: A sustainability scenario which is shaped by environmental regulations and green technology for sustainability, advancements in Building Information Modeling (BIM) are shaping the digitization scenario and integrated project delivery methods form the third scenario “collaboration”. The scenarios developed in this paper support those initially suggested by an AI tool. This analysis enables construction companies to adapt oneself to future scenarios and derive actions

    ATF4 links ER stress with reticulophagy in glioblastoma cells

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    Selective degradation of the endoplasmic reticulum (ER; reticulophagy) is a type of autophagy involved in the removal of ER fragments. So far, amino acid starvation as well as ER stress have been described as inducers of reticulophagy, which in turn restores cellular energy levels and ER homeostasis. Here, we explored the autophagy-inducing mechanisms that underlie the autophagic cell death (ACD)-triggering compound loperamide (LOP) in glioblastoma cells. Interestingly, LOP triggers upregulation of the transcription factor ATF4, which is accompanied by the induction of additional ER stress markers. Notably, knockout of ATF4 significantly attenuated LOP-induced autophagy and ACD. Functionally, LOP also specifically induces the engulfment of large ER fragments within autophagosomes and lysosomes as determined by electron and fluorescence microscopy. LOP-induced reticulophagy and cell death are predominantly mediated through the reticulophagy receptor RETREG1/FAM134B and, to a lesser extent, TEX264, confirming that reticulophagy receptors can promote ACD. Strikingly, apart from triggering LOP-induced autophagy and ACD, ATF4 is also required for LOP-induced reticulophagy. These observations highlight a key role for ATF4, RETREG1 and TEX264 in response to LOP-induced ER stress, reticulophagy and ACD, and establish a novel mechanistic link between ER stress and reticulophagy, with possible implications for additional models of drug-induced ER stress

    Loperamide, pimozide, and STF-62247 trigger autophagy-dependent cell death in glioblastoma cells

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    Autophagy is a well-described degradation mechanism that promotes cell survival upon nutrient starvation and other forms of cellular stresses. In addition, there is growing evidence showing that autophagy can exert a lethal function via autophagic cell death (ACD). As ACD has been implicated in apoptosis-resistant glioblastoma (GBM), there is a high medical need for identifying novel ACD-inducing drugs. Therefore, we screened a library containing 70 autophagy-inducing compounds to induce ATG5-dependent cell death in human MZ-54 GBM cells. Here, we identified three compounds, i.e. loperamide, pimozide, and STF-62247 that significantly induce cell death in several GBM cell lines compared to CRISPR/Cas9-generated ATG5- or ATG7-deficient cells, pointing to a death-promoting role of autophagy. Further cell death analyses conducted using pharmacological inhibitors revealed that apoptosis, ferroptosis, and necroptosis only play minor roles in loperamide-, pimozide- or STF-62247-induced cell death. Intriguingly, these three compounds induce massive lipidation of the autophagy marker protein LC3B as well as the formation of LC3B puncta, which are characteristic of autophagy. Furthermore, loperamide, pimozide, and STF-62247 enhance the autophagic flux in parental MZ-54 cells, but not in ATG5 or ATG7 knockout (KO) MZ-54 cells. In addition, loperamide- and pimozide-treated cells display a massive formation of autophagosomes and autolysosomes at the ultrastructural level. Finally, stimulation of autophagy by all three compounds is accompanied by dephosphorylation of mammalian target of rapamycin complex 1 (mTORC1), a well-known negative regulator of autophagy. In summary, our results indicate that loperamide, pimozide, and STF-62247 induce ATG5- and ATG7-dependent cell death in GBM cells, which is preceded by a massive induction of autophagy. These findings emphasize the lethal function and potential clinical relevance of hyperactivated autophagy in GBM

    STF-62247 and pimozide induce autophagy and autophagic cell death in mouse embryonic fibroblasts

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    Induction of autophagy can have beneficial effects in several human diseases, e.g. cancer and neurodegenerative diseases (ND). Here, we therefore evaluated the potential of two novel autophagy-inducing compounds, i.e. STF-62247 and pimozide, to stimulate autophagy as well as autophagic cell death (ACD) using mouse embryonic fibroblasts (MEFs) as a cellular model. Importantly, both STF-62247 and pimozide triggered several hallmarks of autophagy in MEFs, i.e. enhanced levels of LC3B-II protein, its accumulation at distinct cytosolic sites and increase of the autophagic flux. Intriguingly, autophagy induction by STF-62247 and pimozide resulted in cell death that was significantly reduced in ATG5- or ATG7-deficient MEFs. Consistent with ACD induction, pharmacological inhibitors of apoptosis, necroptosis or ferroptosis failed to protect MEFs from STF-62247- or pimozide-triggered cell death. Interestingly, at subtoxic concentrations, pimozide stimulated fragmentation of the mitochondrial network, degradation of mitochondrial proteins (i.e. mitofusin-2 and cytochrome c oxidase IV (COXIV)) as well as a decrease of the mitochondrial mass, indicative of autophagic degradation of mitochondria by pimozide. In conclusion, this study provides novel insights into the induction of selective autophagy as well as ACD by STF-62247 and pimozide in MEFs

    Comprehensive investigation of novel pore-graded gas diffusion layers for high-performance and costeffective proton exchange membrane electrolyzers

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    Hydrogen produced by water electrolysis is a promising storage medium for renewable energy. Reducing the capital cost of proton exchange membrane (PEM) electrolyzers without losing efficiency is one of its most pressing challenges. Gas diffusion layers (GDL), such as felts, foams, meshes and sintered plates, are key stack components, but these are either inefficient or expensive. This study presents a new type of GDL produced via vacuum plasma spraying (VPS), which offers a large potential for cost reduction. With this technology, it is possible to introduce a gradient in the pore-size distribution along the thickness of the GDL by varying the plasma parameters and titanium powder particle sizes. This feature was confirmed by cross-section scanning electron microscopy (SEM). X-ray computed tomography (CT) and mercury intrusion porosimetry allowed determining the porosity, pore radii distribution, and pore entry distribution. Pore radii of ca. 10 mm could be achieved in the layers of the GDL close to the bipolar plate, while those in contact with the electrodes were in the range of 5 mm. The thermally sprayed Ti-GDLs allowed achieving PEM electrolyzer performances comparable to those of the state-of-the-art sintered plates and far superior than those of meshes. Moreover, a numerical model showed that the reduced capillary pressure and tortuosity eliminates mass transport limitations at 2 A cm-2. The results presented herein demonstrate a promising solution to reduce the cost of one of the most expensive components of the stack

    Loperamide, pimozide, and STF-62247 trigger autophagy-dependent cell death in glioblastoma cells

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    Autophagy is a well-described degradation mechanism that promotes cell survival upon nutrient starvation and other forms of cellular stresses. In addition, there is growing evidence showing that autophagy can exert a lethal function via autophagic cell death (ACD). As ACD has been implicated in apoptosis-resistant glioblastoma (GBM), there is a high medical need for identifying novel ACD-inducing drugs. Therefore, we screened a library containing 70 autophagy-inducing compounds to induce ATG5-dependent cell death in human MZ-54 GBM cells. Here, we identified three compounds, i.e. loperamide, pimozide, and STF-62247 that significantly induce cell death in several GBM cell lines compared to CRISPR/Cas9-generated ATG5- or ATG7-deficient cells, pointing to a death-promoting role of autophagy. Further cell death analyses conducted using pharmacological inhibitors revealed that apoptosis, ferroptosis, and necroptosis only play minor roles in loperamide-, pimozide- or STF-62247-induced cell death. Intriguingly, these three compounds induce massive lipidation of the autophagy marker protein LC3B as well as the formation of LC3B puncta, which are characteristic of autophagy. Furthermore, loperamide, pimozide, and STF-62247 enhance the autophagic flux in parental MZ-54 cells, but not in ATG5 or ATG7 knockout (KO) MZ-54 cells. In addition, loperamide- and pimozide-treated cells display a massive formation of autophagosomes and autolysosomes at the ultrastructural level. Finally, stimulation of autophagy by all three compounds is accompanied by dephosphorylation of mammalian target of rapamycin complex 1 (mTORC1), a well-known negative regulator of autophagy. In summary, our results indicate that loperamide, pimozide, and STF-62247 induce ATG5- and ATG7-dependent cell death in GBM cells, which is preceded by a massive induction of autophagy. These findings emphasize the lethal function and potential clinical relevance of hyperactivated autophagy in GBM

    AT 101 induces early mitochondrial dysfunction and HMOX1 (heme oxygenase 1) to trigger mitophagic cell death in glioma cells

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    <p>In most cases, macroautophagy/autophagy serves to alleviate cellular stress and acts in a pro-survival manner. However, the effects of autophagy are highly contextual, and autophagic cell death (ACD) is emerging as an alternative paradigm of (stress- and drug-induced) cell demise. AT 101 ([-]-gossypol), a natural compound from cotton seeds, induces ACD in glioma cells as confirmed here by CRISPR/Cas9 knockout of <i>ATG5</i> that partially, but significantly rescued cell survival following AT 101 treatment. Global proteomic analysis of AT 101-treated U87MG and U343 glioma cells revealed a robust decrease in mitochondrial protein clusters, whereas HMOX1 (heme oxygenase 1) was strongly upregulated. AT 101 rapidly triggered mitochondrial membrane depolarization, engulfment of mitochondria within autophagosomes and a significant reduction of mitochondrial mass and proteins that did not depend on the presence of BAX and BAK1. Conversely, AT 101-induced reduction of mitochondrial mass could be reversed by inhibiting autophagy with wortmannin, bafilomycin A<sub>1</sub> and chloroquine. Silencing of HMOX1 and the mitophagy receptors BNIP3 (BCL2 interacting protein 3) and BNIP3L (BCL2 interacting protein 3 like) significantly attenuated AT 101-dependent mitophagy and cell death. Collectively, these data suggest that early mitochondrial dysfunction and HMOX1 overactivation synergize to trigger lethal mitophagy, which contributes to the cell killing effects of AT 101 in glioma cells.</p> <p><b>Abbreviations</b>: ACD, autophagic cell death; ACN, acetonitrile; AT 101, (-)-gossypol; BAF, bafilomycin A<sub>1</sub>; BAK1, BCL2-antagonist/killer 1; BAX, BCL2-associated X protein; BH3, BCL2 homology region 3; BNIP3, BCL2 interacting protein 3; BNIP3L, BCL2 interacting protein 3 like; BP, Biological Process; CCCP, carbonyl cyanide m-chlorophenyl hydrazone; CC, Cellular Component; Con, control; CQ, chloroquine; CRISPR, clustered regularly interspaced short palindromic repeats; DMEM, Dulbecco’s Modified Eagle Medium; DTT, 1,4-dithiothreitol; EM, electron microscopy; ER, endoplasmatic reticulum; FACS, fluorescence-activated cell sorting; FBS, fetal bovine serum; FCCP, carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone; GO, Gene Ontology; HAcO, acetic acid; HMOX1, heme oxygenase 1; DKO, double knockout; LC-MS/MS, liquid chromatography coupled to tandem mass spectrometry; LPL, lipoprotein lipase, MEFs, mouse embryonic fibroblasts; mPTP, mitochondrial permeability transition pore; MTG, MitoTracker Green FM; mt-mKeima, mito-mKeima; MT-ND1, mitochondrially encoded NADH:ubiquinone oxidoreductase core subunit 1; PBS, phosphate-buffered saline; PE, phosphatidylethanolamine; PI, propidium iodide; PRKN, parkin RBR E3 ubiquitin protein ligase; SDS, sodium dodecyl sulfate; SQSTM1/p62, sequestome 1; STS, staurosporine; sgRNA, single guide RNA; SILAC, stable isotope labeling with amino acids in cell culture; TFA, trifluoroacetic acid, TMRM, tetramethylrhodamine methyl ester perchlorate; WM, wortmannin; WT, wild-type</p
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