bims-lymeca 2023-09-17 papers

bims-lymeca

Biomed News

on Lysosome metabolism in cancer

Issue of 2023–09–17
nine papers selected by
Harilaos Filippakis, University of New England

Codependencies of mTORC1 signaling and endolysosomal actin structures.
Continuous sensing of nutrients and growth factors by the mTORC1-TFEB axis.
TFEB.
TFEB and TFE3 control glucose homeostasis by regulating insulin gene expression.
β-Elemene induced ferroptosis via TFEB-mediated GPX4 degradation in EGFR wide-type non-small cell lung cancer.
Tau fibrils induce nanoscale membrane damage and nucleate cytosolic tau at lysosomes.
Alternative to lysosomal degradation: mitochondrial removal via EVs.
Light controlled self-escape capability of non-cationic carbon nitride-based nanosheets in lysosomes for hepatocellular carcinoma targeting stimulus-responsive gene delivery.
Ultralow background membrane editors for spatiotemporal control of lipid metabolism and signaling.

Sci Adv. 2023 Sep 15. 9(37): eadd9084

Codependencies of mTORC1 signaling and endolysosomal actin structures.

Amulya Priya, Sandra Antoine-Bally, Anne-Sophie Macé, Pedro Monteiro, Valentin Sabatet, David Remy, Florent Dingli, Damarys Loew, Constantinos Demetriades, Alexis M Gautreau, Philippe Chavrier.

The mechanistic target of rapamycin complex 1 (mTORC1) is part of the amino acid sensing machinery that becomes activated on the endolysosomal surface in response to nutrient cues. Branched actin generated by WASH and Arp2/3 complexes defines endolysosomal microdomains. Here, we find mTORC1 components in close proximity to endolysosomal actin microdomains. We investigated for interactors of the mTORC1 lysosomal tether, RAGC, by proteomics and identified multiple actin filament capping proteins and their modulators. Perturbation of RAGC function affected the size of endolysosomal actin, consistent with a regulation of actin filament capping by RAGC. Reciprocally, the pharmacological inhibition of actin polymerization or alteration of endolysosomal actin obtained upon silencing of WASH or Arp2/3 complexes impaired mTORC1 activity. Mechanistically, we show that actin is required for proper association of RAGC and mTOR with endolysosomes. This study reveals an unprecedented interplay between actin and mTORC1 signaling on the endolysosomal system.

DOI: https://doi.org/10.1126/sciadv.add9084
Elife. 2023 Sep 12. pii: e74903. [Epub ahead of print]12

Continuous sensing of nutrients and growth factors by the mTORC1-TFEB axis.

Breanne Sparta, Nont Kosaisawe, Michael Pargett, Madhura Patankar, Nicholaus DeCuzzi, John G Albeck.

  mTORC1 senses nutrients and growth factors and phosphorylates downstream targets, including the transcription factor TFEB, to coordinate metabolic supply and demand. These functions position mTORC1 as a central controller of cellular homeostasis, but the behavior of this system in individual cells has not been well characterized. Here, we provide measurements necessary to refine quantitative models for mTORC1 as a metabolic controller. We developed a series of fluorescent protein-TFEB fusions and a multiplexed immunofluorescence approach to investigate how combinations of stimuli jointly regulate mTORC1 signaling at the single-cell level. Live imaging of individual MCF10A cells confirmed that mTORC1-TFEB signaling responds continuously to individual, sequential, or simultaneous treatment with amino acids and the growth factor insulin. Under physiologically relevant concentrations of amino acids, we observe correlated fluctuations in TFEB, AMPK, and AKT signaling that indicate continuous activity adjustments to nutrient availability. Using partial least squares regression modeling, we show that these continuous gradations are connected to protein synthesis rate via a distributed network of mTORC1 effectors, providing quantitative support for the qualitative model of mTORC1 as a homeostatic controller and clarifying its functional behavior within individual cells.

Keywords:  cell biology; computational biology; human; systems biology

DOI:  https://doi.org/10.7554/eLife.74903
Curr Biol. 2023 Sep 11. pii: S0960-9822(23)00820-5. [Epub ahead of print]33(17): R886-R888

TFEB.

Pablo S Contreras, Rosa Puertollano.

Contreras and Puertollano introduce TFEB, a transcription factor that orchestrates cellular responses to stress via mechanisms including upregulation of lysosome biogenesis and autophagy.

DOI: https://doi.org/10.1016/j.cub.2023.06.035
EMBO J. 2023 Sep 15. e113928

TFEB and TFE3 control glucose homeostasis by regulating insulin gene expression.

Adrien Pasquier, Nunzia Pastore, Luca D'Orsi, Rita Colonna, Alessandra Esposito, Veronica Maffia, Rossella De Cegli, Margherita Mutarelli, Susanna Ambrosio, Gennaro Tufano, Antonio Grimaldi, Marcella Cesana, Davide Cacchiarelli, Nathalie Delalleau, Gennaro Napolitano, Andrea Ballabio.

  To fulfill their function, pancreatic beta cells require precise nutrient-sensing mechanisms that control insulin production. Transcription factor EB (TFEB) and its homolog TFE3 have emerged as crucial regulators of the adaptive response of cell metabolism to environmental cues. Here, we show that TFEB and TFE3 regulate beta-cell function and insulin gene expression in response to variations in nutrient availability. We found that nutrient deprivation in beta cells promoted TFEB/TFE3 activation, which resulted in suppression of insulin gene expression. TFEB overexpression was sufficient to inhibit insulin transcription, whereas beta cells depleted of both TFEB and TFE3 failed to suppress insulin gene expression in response to amino acid deprivation. Interestingly, ChIP-seq analysis showed binding of TFEB to super-enhancer regions that regulate insulin transcription. Conditional, beta-cell-specific, Tfeb-overexpressing, and Tfeb/Tfe3 double-KO mice showed severe alteration of insulin transcription, secretion, and glucose tolerance, indicating that TFEB and TFE3 are important physiological mediators of pancreatic function. Our findings reveal a nutrient-controlled transcriptional mechanism that regulates insulin production, thus playing a key role in glucose homeostasis at both cellular and organismal levels.

Keywords:  TFEB; beta cells; glucose homeostasis; insulin; mTORC1

DOI:  https://doi.org/10.15252/embj.2023113928
J Adv Res. 2023 Sep 07. pii: S2090-1232(23)00234-5. [Epub ahead of print]

β-Elemene induced ferroptosis via TFEB-mediated GPX4 degradation in EGFR wide-type non-small cell lung cancer.

Li-Ping Zhao, Hao-Jie Wang, Die Hu, Jun-Hu Hu, Zheng-Rong Guan, Li-Hua Yu, Ya-Ping Jiang, Xiao-Qi Tang, Zhao-Huang Zhou, Tian Xie, Jian-Shu Lou.

   INTRODUCTION: β-Elemene (β-ELE), derived from Curcuma wenyujin, has anticancer effect on non-small cell lung cancer (NSCLC). However, the potential target and detail mechanism were still not clear. TFEB is the master regulator of lysosome biogenesis. Ferroptosis, a promising strategy for cancer therapy could be triggered via suppression on glutathione peroxidase 4 (GPX4). Weather TFEB-mediated lysosome degradation contributes to GPX4 decline and how β-ELE modulates on this process are not clear.
OBJECTIVES: To observe the action of β-ELE on TFEB, and the role of TFEB-mediated GPX4 degradation in β-ELE induced ferroptosis.
METHODS: Surface plasmon resonance (SPR) and molecular docking were applied to observe the binding affinity of β-ELE on TFEB. Activation of TFEB and lysosome were observed by immunofluorescence, western blot, flow cytometry and qPCR. Ferroptosis induced by β-ELE was observed via lipid ROS, a labile iron pool (LIP) assay and western blot. A549TFEB KO cells were established via CRISPR/Cas9. The regulation of TFEB on GPX4 and ferroptosis was observed in β-ELE treated A549WT and A549TFEB KO cells, which was further studied in orthotopic NOD/SCID mouse model.
RESULTS: β-ELE can bind to TFEB, notably activate TFEB, lysosome and transcriptional increase on downstream gene GLA, MCOLN1, SLC26A11 involved in lysosome activity in EGFR wild-type NSCLC cells. β-ELE increased GPX4 ubiquitination and lysosomal localization, with the increase on lysosome degradation of GPX4. Furthermore, β-ELE induced ferroptosis, which could be promoted by TFEB overexpression or compromised by TFEB knockout. Genetic knockout or inactivation of TFEB compromised β-ELE induced lysosome degradation of GPX4, which was further demonstrated in orthotopic NOD/SCID NSCLC mice model.
CONCLUSION: This study firstly demonstrated that TFEB promoted GPX4 lysosome degradation contributes to β-ELE induced ferroptosis in EGFR wild-type NSCLC, which gives a clue that TFEB mediated GPX4 degradation would be a novel strategy for ferroptosis induction and NSCLC therapy.

Keywords:  TFEB; ferroptosis; lysosome; non-small cell lung cancer; β- Elemene

DOI:  https://doi.org/10.1016/j.jare.2023.08.018
bioRxiv. 2023 Aug 28. pii: 2023.08.28.555157. [Epub ahead of print]

Tau fibrils induce nanoscale membrane damage and nucleate cytosolic tau at lysosomes.

Kevin Rose, Tyler Jepson, Sankalp Shukla, Alex Maya-Romero, Martin Kampmann, Ke Xu, James H Hurley.

The prion-like spread of protein aggregates is a leading hypothesis for the propagation of neurofibrillary lesions in the brain, including the spread of tau inclusions associated with Alzheimer's disease. The mechanisms of cellular uptake of tau seeds and subsequent nucleated polymerization of cytosolic tau are major questions in the field, and the potential for coupling between the entry and nucleation mechanisms has been little explored. We found that in primary astrocytes, endocytosis of tau seeds leads to their accumulation in lysosomes. This in turn leads to lysosomal swelling, deacidification and recruitment of ESCRT proteins, but not Galectin-3, to the lysosomal membrane. These observations are consistent with nanoscale damage of the lysosomal membrane. Using live cell and STORM, imaging, nucleation of cytosolic tau occurs primarily at the lysosome membrane under these conditions. These data suggest that tau seeds escape from lysosomes via nanoscale damage rather than wholesale rupture, and that nucleation of cytosolic tau commences as soon as tau fibril ends emerge from the lysosomal membrane.

DOI: https://doi.org/10.1101/2023.08.28.555157
Nat Rev Mol Cell Biol. 2023 Sep 11.

Alternative to lysosomal degradation: mitochondrial removal via EVs.

Paulina Strzyz.

DOI: https://doi.org/10.1038/s41580-023-00660-5
Bioeng Transl Med. 2023 Sep;8(5): e10558

Light controlled self-escape capability of non-cationic carbon nitride-based nanosheets in lysosomes for hepatocellular carcinoma targeting stimulus-responsive gene delivery.

Ming-Xuan Liu, Li Xu, Jia-Yi Jiang, Hai-Chen Dong, Peng-Fei Zhu, Lei Cao, Jing Chen, Xiao-Ling Zhang.

  High positive charge-induced toxicity, easy lysosomal degradation of nucleic acid drugs, and poor lesion sites targeting are major problems faced in the development of gene carriers. Herein, we proposed the concept of self-escape non-cationic gene carriers for targeted delivery and treatment of photocontrolled hepatocellular carcinoma (HCC) with sufficient lysosome escape and multiple response capacities. Functional DNA was bound to the surface of biotin-PEG2000-modified graphitic carbon nitride (Bio-PEG-CN) nanosheets to form non-cationic nanocomplexes Bio-PEG-CN/DNA. These nanocomposites could actively target HCC tissue. Once these nanocomplexes were taken up by tumor cells, the accumulated reactive oxygen species (ROS) generated by Bio-PEG-CN under LED irradiation would disrupt the lysosome structure, thereby facilitating nanocomposites escape. Due to the acidic microenvironment and lipase in the HCC tissue, the reversible release of DNA could be promoted to complete the transfection process. Meanwhile, the fluorescence signal of Bio-PEG-CN could be monitored in real time by fluorescence imaging technology to investigate the transfection process and mechanism. In vitro and in vivo results further demonstrated that these nanocomplexes could remarkably upregulate the expression of tumor suppressor protein P53, increased tumor sensitivity to ROS generated by nanocarriers, and realized effective gene therapy for HCC via loading P53 gene.

Keywords:  CN‐based nanosheets; gene delivery; gene therapy; light controlled; non‐cationic carrier

DOI:  https://doi.org/10.1002/btm2.10558
bioRxiv. 2023 Aug 31. pii: 2023.08.31.555787. [Epub ahead of print]

Ultralow background membrane editors for spatiotemporal control of lipid metabolism and signaling.

Xiang-Ling Li, Reika Tei, Masaaki Uematsu, Jeremy M Baskin.

Phosphatidic acid (PA) is a multifunctional lipid with important metabolic and signaling functions, and efforts to dissect its pleiotropy demand strategies for perturbing its levels with spatiotemporal precision. Previous membrane editing approaches for generating local PA pools used light-mediated induced proximity to recruit a PA-synthesizing enzyme, phospholipase D (PLD), from the cytosol to the target organelle membrane. Whereas these optogenetic PLDs exhibited high activity, their residual activity in the dark led to undesired chronic lipid production. Here, we report ultralow background membrane editors for PA wherein light directly controls PLD catalytic activity, as opposed to localization and access to substrates, exploiting a LOV domain-based conformational photoswitch inserted into the PLD sequence and enabling their stable and non-perturbative targeting to multiple organelle membranes. By coupling organelle-targeted LOVPLD activation to lipidomics analysis, we discovered different rates of metabolism for PA and its downstream products depending on the subcellular location of PA production. We also elucidated signaling roles for PA pools on different membranes in conferring local activation of AMP-activated protein kinase signaling. This work illustrates how membrane editors featuring acute, optogenetic conformational switches can provide new insights into organelle-selective lipid metabolic and signaling pathways.
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DOI: https://doi.org/10.1101/2023.08.31.555787