Autophagy and lysosomal dysfunction in Tay Sachs disease are restored by mTOR modulation
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ABSTRACT:
PROVIDER: PRJNA767011 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Tay-Sachs disease (TSD) is a inherited lysosomal storage disease resulting from mutations in the α-subunits of the lysosomal enzyme, β-hexosaminidase A, and leads to excessive accumulation of GM2 ganglioside. This disease can be presented in infantil, juvenil and adult forms with rapid, progressive neurodegeneration. Although the link between mTOR and autophagy in Taysachs diseases has not been previously examined, it is reasonably to infer that reduced activity of HexA and the consequent intracellular accumulation of undegraded ganglyosides could lead accumulation of lysosomes, other substrates or dysfunctional organelles, similar to other defects detected in other LSD. In the present study, we show that skin fibroblasts derived from PLS patients presented increased p62/SQSTM1 expression levels and autophagosome accumulation suggesting an impaired autophagic flux.
2021-09-30 | GSE184906 | GEO
Project description:Lysosomal cathepsins regulate an exquisite range of biological functions, and their deregulation is associated with inflammatory, metabolic and degenerative disease in humans. Here, we identified a key cell-intrinsic role for cathepsin B as a negative feedback regulator of lysosomal biogenesis and autophagy. Mice and macrophages lacking cathepsin B activity had increased resistance to the cytosolic bacterial pathogen Francisella novicida. Genetic deletion or pharmacological inhibition of cathepsin B downregulated mTOR activity and prevented cleavage of the lysosomal calcium channel TRPML1. These events drove transcription of lysosomal and autophagy genes via the transcription factor TFEB, which increased lysosomal biogenesis and activation of autophagy-initiation kinase ULK1 for clearance of the bacteria. Our results identified a fundamental biological function of cathepsin B in providing a checkpoint for homeostatic maintenance of lysosome population and basic recycling functions in the cell. We used microarrays to explore the gene expression profiles differentially expressed in bone marrow-derived macrophages (BMDM) isolated from cathepsin B-/- and wild-type mice.
2016-08-04 | E-GEOD-79508 | biostudies-arrayexpress
Project description:The PI3K-PKB/c-akt-FOXO signalling network provides a major intracellular hub for regulation of cell proliferation, survival and stress resistance1. Here we report a novel function for FOXO transcription factors in regulating autophagy through modulation of intracellular glutamine levels. To identify novel transcriptional targets of this module we performed an unbiased microarray analysis after conditional activation of the key components PI3K, PKB, FOXO3 and FOXO4. Utilising this global pathway approach we identified glutamine synthetase (GS) as being transcriptionally regulated by PI3K-PKB-FOXO signalling. FOXO-mediated increase in GS expression specifically induced glutamine production independently of cell type, and this was evolutionary conserved. FOXO activation resulted in mTOR inhibition by preventing the translocation of mTOR to lysosomal membranes, which was dependent on GS activity. Increased GS activity resulted in increased autophagosome turnover as measured by LC3 lipidation, p62 degradation, and confocal imaging of LC3, p62, WIPI-1, ULK2 and Atg12. Inhibition of FOXO3-mediated autophagy resulted in increased apoptosis, suggesting that the induction of autophagy by FOXO3-mediated upregulation of GS is important for cellular survival. These findings reveal a novel signalling network that can directly modulate autophagy through regulation of glutamine metabolism. conditional activation of pkb and pi3k were followed in a timeseries. Each timepoint consists of 4 independent replicates, labeled with either cy3 or cy5 and put on array against time0.
2012-07-21 | E-GEOD-35701 | biostudies-arrayexpress
Project description:The PI3K-PKB/c-akt-FOXO signalling network provides a major intracellular hub for regulation of cell proliferation, survival and stress resistance1. Here we report a novel function for FOXO transcription factors in regulating autophagy through modulation of intracellular glutamine levels. To identify novel transcriptional targets of this module we performed an unbiased microarray analysis after conditional activation of the key components PI3K, PKB, FOXO3 and FOXO4. Utilising this global pathway approach we identified glutamine synthetase (GS) as being transcriptionally regulated by PI3K-PKB-FOXO signalling. FOXO-mediated increase in GS expression specifically induced glutamine production independently of cell type, and this was evolutionary conserved. FOXO activation resulted in mTOR inhibition by preventing the translocation of mTOR to lysosomal membranes, which was dependent on GS activity. Increased GS activity resulted in increased autophagosome turnover as measured by LC3 lipidation, p62 degradation, and confocal imaging of LC3, p62, WIPI-1, ULK2 and Atg12. Inhibition of FOXO3-mediated autophagy resulted in increased apoptosis, suggesting that the induction of autophagy by FOXO3-mediated upregulation of GS is important for cellular survival. These findings reveal a novel signalling network that can directly modulate autophagy through regulation of glutamine metabolism. conditional activation of foxo3 and foxo4 were followed in a timeseries. Each timepoint consists of 4 independent replicates, labeled with either cy3 or cy5 and put on array against time0 as reference.
2012-07-21 | E-GEOD-35703 | biostudies-arrayexpress
Project description:Stress granule formation is a part of cellular homeostatic responses, with prototypical inducers being viral infections, heat shock and oxidative damage. Here we show that lysosomal damage is a previously unappreciated robust inducer of stress granule formation interlinked with mTOR inactivation during lysosomal damage. We find the two processes to be coordinated by a non-autophagy function of mammalian Atg8 proteins (mAtg8s). Stress granules were induced in response to biochemical damage and diverse lysosome damaging biological agents including SARS-CoV-2 ORF3a, Mycobacterium tuberculosis and protopathic tau. Proteomic analyses of purified lysosomes subjected to biochemical damage revealed recruitment to lysosomes of a network of stress granule proteins, including G3BP1 and NUFIP2. G3BP1 and NUFIP2 contributed to inactivation of mTOR during lysosomal damage via the Ragulator-RagA/B system. Lysosomal damage recruited a subset of mAtg8s commonly related to autophagy but also known to associate with other stressed or remodeling membranes. The GABARAP subset of mAtg8s interacted with G3BP1 and NUFIP2 and were required for NUFIP2 and G3BP1 recruitment to the damaged lysosomes. GABARAPs acted as a switch between the utilization of G3BP1 and NUFIP2 in stress granule formation vs. their role in mTOR inactivation. We furthermore found that mAtg8s lipidation, referred herein as Atg8ylation to distinguish it from its conventional implication in autophagy, but not the canonical autophagy factors ATG13, FIP200, and ATG9A, favored mTOR inactivation during lysosomal damage vs. the stress granule formation. Thus, cells utilize Atg8ylation as a response to membrane stress for specific outcomes beyond the process of autophagy, which include the coordinated stress granule formation and mTOR inactivation during lysosomal damage
| MSV000088152 | MassIVE
Project description:The Ser/Thr protein kinase mTOR controls metabolic pathways, including the catabolic process of autophagy. Autophagy plays additional, catabolism-independent roles in homeostasis of cytoplasmic endomembranes and whole organelles. How signals from endomembrane damage are transmitted to mTOR to orchestrate autophagic responses is not known. Here we show that mTOR is inhibited by lysosomal damage. Lysosomal damage, recognized by galectins, leads to association of Gal8 with mTOR apparatus on the lysosome. Gal8 inhibits mTOR activity through its Ragulator-Rag signaling machinery. Thus, a novel galectin-based signal-transduction apparatus, termed here GALTOR, controls mTOR in response to lysosomal damage.
2017-12-07 | MSV000081788 | MassIVE
Project description:Protein synthesis and autophagic degradation are regulated in an opposite manner by mammalian target of rapamycin (mTOR), whereas under certain conditions it would be beneficial if they occured in unison to handle rapid protein turnover. We observed a distinct cellular compartment at the trans-side of the Golgi apparatus, the ‘TOR-autophagy spatial coupling compartment’ (TASCC), where (auto)lysosomes and mTOR accumulated during Ras-induced senescence. mTOR recruitment to the TASCC was amino acid- and Rag guanosine triphosphatase (GTPase)-dependent, and disruption of mTOR localization to the TASCC suppressed interleukin-6/8 synthesis. TASCC-formation was observed during macrophage differentiation and in glomerular podocytes; both displayed increased protein secretion. The spatial coupling of cells’ catabolic and anabolic machinery could augment their respective functions and facilitate the mass synthesis of secretory proteins. To compare gene expression profile between growing and oncogenic Ras induced senescence, 4OHT inducible ER:H-RasV12 was stably expressed in IMR90 human diploid fibroblasts. Total RNA was isolated from day 0 and day 4 after 4OHT addition. There were 3 biological replicates for each of day0 and day 4 timepoints.
2011-05-04 | E-GEOD-28464 | biostudies-arrayexpress
Project description:Lysosomal cathepsins regulate an exquisite range of biological functions, and their deregulation is associated with inflammatory, metabolic and degenerative disease in humans. Here, we identified a key cell-intrinsic role for cathepsin B as a negative feedback regulator of lysosomal biogenesis and autophagy. Mice and macrophages lacking cathepsin B activity had increased resistance to the cytosolic bacterial pathogen Francisella novicida. Genetic deletion or pharmacological inhibition of cathepsin B downregulated mTOR activity and prevented cleavage of the lysosomal calcium channel TRPML1. These events drove transcription of lysosomal and autophagy genes via the transcription factor TFEB, which increased lysosomal biogenesis and activation of autophagy-initiation kinase ULK1 for clearance of the bacteria. Our results identified a fundamental biological function of cathepsin B in providing a checkpoint for homeostatic maintenance of lysosome population and basic recycling functions in the cell.
2016-08-04 | GSE79508 | GEO
Project description:The mTOR-allosteric inhibitor, RAD001, in combination with a PI3K/mTOR ATP-site competitive inhibitor, BEZ235, causes gene reprogramming, autophagy and tumor regression, in a mouse model approximating human HCC with poor prognosis, leading to an investigator Phase 1B-2 clinical trial. Comparative study of total RNA obtained from normal and tumor liver tissue under RAD001, BEZ235, or RAD001 + BEZ235.
2012-07-11 | E-GEOD-37129 | biostudies-arrayexpress
Project description:The PI3K-PKB/c-akt-FOXO signalling network provides a major intracellular hub for regulation of cell proliferation, survival and stress resistance1. Here we report a novel function for FOXO transcription factors in regulating autophagy through modulation of intracellular glutamine levels. To identify novel transcriptional targets of this module we performed an unbiased microarray analysis after conditional activation of the key components PI3K, PKB, FOXO3 and FOXO4. Utilising this global pathway approach we identified glutamine synthetase (GS) as being transcriptionally regulated by PI3K-PKB-FOXO signalling. FOXO-mediated increase in GS expression specifically induced glutamine production independently of cell type, and this was evolutionary conserved. FOXO activation resulted in mTOR inhibition by preventing the translocation of mTOR to lysosomal membranes, which was dependent on GS activity. Increased GS activity resulted in increased autophagosome turnover as measured by LC3 lipidation, p62 degradation, and confocal imaging of LC3, p62, WIPI-1, ULK2 and Atg12. Inhibition of FOXO3-mediated autophagy resulted in increased apoptosis, suggesting that the induction of autophagy by FOXO3-mediated upregulation of GS is important for cellular survival. These findings reveal a novel signalling network that can directly modulate autophagy through regulation of glutamine metabolism.
2012-07-22 | GSE35701 | GEO