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- Corman, Alba, et al.
(author)
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A chemical screen for modulators of mRNA translation identifies a distinct mechanism of toxicity for sphingosine kinase inhibitors
- 2021
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In: PLoS biology. - : Public library of science. - 1544-9173 .- 1545-7885. ; 19:5
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Journal article (peer-reviewed)abstract
- We here conducted an image-based chemical screen to evaluate how medically approved drugs, as well as drugs that are currently under development, influence overall translation levels. None of the compounds up-regulated translation, which could be due to the screen being performed in cancer cells grown in full media where translation is already present at very high levels. Regarding translation down-regulators, and consistent with current knowledge, inhibitors of the mechanistic target of rapamycin (mTOR) signaling pathway were the most represented class. In addition, we identified that inhibitors of sphingosine kinases (SPHKs) also reduce mRNA translation levels independently of mTOR. Mechanistically, this is explained by an effect of the compounds on the membranes of the endoplasmic reticulum (ER), which activates the integrated stress response (ISR) and contributes to the toxicity of SPHK inhibitors. Surprisingly, the toxicity and activation of the ISR triggered by 2 independent SPHK inhibitors, SKI-II and ABC294640, the latter in clinical trials, are also observed in cells lacking SPHK1 and SPHK2. In summary, our study provides a useful resource on the effects of medically used drugs on translation, identified compounds capable of reducing translation independently of mTOR and has revealed that the cytotoxic properties of SPHK inhibitors being developed as anticancer agents are independent of SPHKs.
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| 2. |
- Engström-Ruud, Linda, et al.
(author)
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Activation of GFRAL+ neurons induces hypothermia and glucoregulatory responses associated with nausea and torpor.
- 2024
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In: Cell reports. - 2211-1247. ; 43:4
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Journal article (peer-reviewed)abstract
- GFRAL-expressing neurons actuate aversion and nausea, are targets for obesity treatment, and may mediate metformin effects by long-term GDF15-GFRAL agonism. Whether GFRAL+ neurons acutely regulate glucose and energy homeostasis is, however, underexplored. Here, we report that cell-specific activation of GFRAL+ neurons using a variety of techniques causes a torpor-like state, including hypothermia, the release of stress hormones, a shift from glucose to lipid oxidation, and impaired insulin sensitivity, glucose tolerance, and skeletal muscle glucose uptake but augmented glucose uptake in visceral fat. Metabolomic analysis of blood and transcriptomics of muscle and fat indicate alterations in ketogenesis, insulin signaling, adipose tissue differentiation and mitogenesis, and energy fluxes. Our findings indicate that acute GFRAL+ neuron activation induces endocrine and gluco- and thermoregulatory responses associated with nausea and torpor. While chronic activation of GFRAL signaling promotes weight loss in obesity, these results show that acute activation of GFRAL+ neurons causes hypothermia and hyperglycemia.
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| 3. |
- Koh, Ara, et al.
(author)
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Microbially Produced Imidazole Propionate Impairs Insulin Signaling through mTORC1
- 2018
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In: Cell. - : Elsevier BV. - 0092-8674. ; 175:4
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Journal article (peer-reviewed)abstract
- Interactions between the gut microbiota, diet, and the host potentially contribute to the development of metabolic diseases. Here, we identify imidazole propionate as a microbially produced histidine-derived metabolite that is present at higher concentrations in subjects with versus without type 2 diabetes. We show that imidazole propionate is produced from histidine in a gut simulator at higher concentrations when using fecal microbiota from subjects with versus without type 2 diabetes and that it impairs glucose tolerance when administered to mice. We further show that imidazole propionate impairs insulin signaling at the level of insulin receptor substrate through the activation of p38 gamma MAPK, which promotes p62 phosphorylation and, subsequently, activation of mechanistic target of rapamycin complex 1 (mTORC1). We also demonstrate increased activation of p62 and mTORC1 in liver from subjects with type 2 diabetes. Our findings indicate that the microbial metabolite imidazole propionate may contribute to the pathogenesis of type 2 diabetes.
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| 5. |
- Prats-Uribe, Albert, et al.
(author)
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High-density lipoprotein characteristics and coronary artery disease : a Mendelian randomization study
- 2020
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In: Metabolism. - : W B SAUNDERS CO-ELSEVIER INC. - 0026-0495 .- 1532-8600. ; 112
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Journal article (peer-reviewed)abstract
- Background: To assess whether genetically determined quantitative and qualitative HDL characteristics were independently associated with coronary artery disease (CAD). Methods: We designed a two-sample multivariate Mendelian randomization study with available genome-wide association summary data. We identified genetic variants associated with HDL cholesterol and apolipoprotein A-I levels, HDL size, particle levels, and lipid content to define our genetic instrumental variables in one sample (Kettunen et al. study, n = 24,925) and analyzed their association with CAD risk in a different study (CARDloGRAMplusC4D, n = 184,305). We validated these results by defining our genetic variables in another database (METSINI, n = 8372) and studied their relationship with CAD in the CARDloGRAMplusC4D dataset. To estimate the effect size of the associations of interest adjusted for other lipoprotein traits and minimize potential pleiotropy, we used the Multi-trait-based Conditional & Joint analysis. Results: Genetically determined HDL cholesterol and apolipoprotein A-I levels were not associated with CAD. HDL mean diameter (beta = 027 [95%CI = 0.19; 0.35]), cholesterol levels in very large HDLs (beta = 0.29 (95%CI = 0.17; 0.40]), and triglyceride content in very large HDIs (beta = 0.14 [95%CI = 0.040; 025]) were directly associated with CAD risk, whereas the cholesterol content in medium-sized HDLs (beta = -0.076 [95%CI = -0.10; -0.052]) was inversely related to this risk. These results were validated in the METSIM-CARDloGRAMplu5C4D data. Conclusions: Some qualitative HDL characteristics (related to size, particle distribution, and cholesterol and triglyceride content) are related to CAD risk while HDL cholesterol levels are not. (C) 2020 Elsevier Inc. All rights reserved.
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