Cellular acidosis triggers MondoA transcriptional activity by driving mitochondrial ATP production
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PROVIDER: PRJNA482669 | ENA |
REPOSITORIES: ENA
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Project description:MondoA and its transcriptional target thioredoxin-interacting protein (TXNIP) constitute a regulatory loop that senses glycolytic flux and controls glucose availability. Cellular stress also triggers MondoA activity and TXNIP expression. To understand how MondoA integrates glucose and stress signals, we studied its activation by acidosis. We found that acidosis drives mitochondrial ATP (mtATP) synthesis. The subsequent export of mtATP from mitochondria via adenine-nucleotide transporter and voltage-dependent anion channel, and the enzymatic activity of mitochondria-bound hexokinase results in the production of glucose-6-phosphate (G6P), a known activator of MondoA transcriptional activity. MondoA localizes to the outer-mitochondrial membrane (OMM), and in response to G6P, shuttles to the nucleus and activates transcription. Our data suggests that MondoA is a required feature of a glucose- and mtATP-dependent, OMM-localized signaling center. We propose MondoA functions as a coincidence detector and its ability to sense glucose and cellular stress is coupled to the concerted production of G6P.
2019-01-23 | GSE117622 | GEO
Project description:[1] Lactic acidosis time course: MCF7 cells were exposed to lactic acidosis for different length of time. We used microarrays to examine the genomic programs of cells incubated under lactic acidosis for different length of time [2] Metabolic profiling: MCF7 cells were exposed to control condition, 25mM lactic acidosis, glucose deprivation (zero glucose) and hypoxia (1% oxygen level). [3] Mouse study: Lactic acidosis triggers starvation response with paradoxical induction of TXNIP through MondoA. Wild-type mouse embryo fibroblasts (MEFs) and TXNIP-null MEFs were exposed to Ctrl versus lactic acidosis conditions for 24hrs and the RNAs from cells were extracted with MiRVana kit (Ambion) and applied to Affymetrix 430A mouse chips We used microarrays to examine the genomic programs of cells incubated under different microenvironmental stresses. [1] Lactic acidosis time course: MCF7 cells were exposed to lactic acidosis for 1, 4, 12 and 24 hours. [2] Metabolic profiling: MCF7 cells were exposed to lactic acidosis, glucose deprivation and hypoxia for 4hours. [3] wild-type mouse embryo fibroblasts (MEFs) and TXNIP-null MEFs were exposed to Ctrl versus lactic acidosis conditions for 24hrs.
2010-09-27 | E-GEOD-19123 | biostudies-arrayexpress
Project description:[1] Lactic acidosis time course: MCF7 cells were exposed to lactic acidosis for different length of time. We used microarrays to examine the genomic programs of cells incubated under lactic acidosis for different length of time [2] Metabolic profiling: MCF7 cells were exposed to control condition, 25mM lactic acidosis, glucose deprivation (zero glucose) and hypoxia (1% oxygen level). [3] Mouse study: Lactic acidosis triggers starvation response with paradoxical induction of TXNIP through MondoA. Wild-type mouse embryo fibroblasts (MEFs) and TXNIP-null MEFs were exposed to Ctrl versus lactic acidosis conditions for 24hrs and the RNAs from cells were extracted with MiRVana kit (Ambion) and applied to Affymetrix 430A mouse chips We used microarrays to examine the genomic programs of cells incubated under different microenvironmental stresses.
2010-09-27 | GSE19123 | GEO
Project description: Not available
| S-EPMC6363388 | biostudies-literature
Project description:Human MondoA requires glucose as well as other modulatory signals to function in transcription. One such signal is acidosis, which increases MondoA activity and also drives a protective gene signature breast cancer. How low pH controls MondoA transcriptional activity is unknown. We found that low pH medium increases mitochondrial ATP (mtATP), which is subsequently exported from the mitochondrial matrix. Mitochondria-bound hexokinase transfers a phosphate from mtATP to cytoplasmic glucose to generate glucose-6-phosphate (G6P), which is an established MondoA activator. The outer mitochondrial membrane localization of MondoA suggests that it is positioned to coordinate the adaptive transcriptional response to a cell’s most abundant energy sources, cytoplasmic glucose and mtATP. In response to acidosis, MondoA shows preferential binding to just two targets, TXNIP and its paralog ARRDC4. Because these transcriptional targets are suppressors of glucose uptake we propose that MondoA is critical for restoring metabolic homeostasis in response to high energy charge.
2019-01-23 | GSE125089 | GEO
Project description:BACKGROUND: Protein synthesis is regulated by the availability of amino acids, the engagement of growth factor signaling pathways and ATP levels sufficient to support translation. Crosstalk between these inputs is extensive, yet other regulatory mechanisms remain to be characterized. For example, the translation initiation inhibitor Rocaglamide A (RocA) induces Thioredoxin Interacting Protein (TXNIP). TXNIP is a negative regulator of glucose uptake, thus its induction by RocA links translation to the availability of glucose. MondoA is the principal regulator of glucose-induced transcription and its activity is triggered by the glycolytic intermediate, glucose 6-phosphate (G6P). MondoA responds to G6P generated by cytoplasmic glucose and mitochondrial ATP (mtATP), suggesting a critical role in the cellular response to these energy sources. TXNIP expression is entirely dependent on MondoA, therefore, we investigated how protein synthesis inhibitors impact its transcriptional activity. METHODS: We investigated how translation regulates MondoA activity using cell line models and loss-of-function approaches. We examined how protein synthesis inhibitors effect gene expression and metabolism using RNA-sequencing and metabolomics, respectively. The biological impact of RocA was evaluated using both cell line models and Patient-Derived Xenograft Organoid models. RESULTS: We discovered that multiple protein synthesis inhibitors, including RocA, increase TXNIP expression in a manner that depends on MondoA, a functional electron transport chain and mtATP synthesis. Furthermore, RocA increases mtATP and G6P levels and TXNIP induction depends on interactions between the Voltage-Dependent Anion Channel (VDAC) and hexokinase, which generates G6P. RocA treatment impacts the regulation of ~1200 genes and ~250 of those genes are MondoA-dependent. RocA treatment is cytotoxic to Triple Negative Breast Cancer cell lines and shows preferential cytotoxicity against ER- patient-derived breast cancer models. Finally, RocA-driven cytotoxicity is partially-dependent on MondoA or TXNIP. CONCLUSION: Our data suggest that protein synthesis inhibitors rewire metabolism, resulting in an increase in mtATP and G6P, the latter driving MondoA-dependent transcriptional activity. Further, MondoA is a critical component of the cellular transcriptional response to RocA. Our functional assays suggest that RocA or similar translation inhibitors may show efficacy against ER- tumors and that the levels of MondoA and TXNIP should be considered when exploring these potential treatment options.
2020-12-07 | GSE153499 | GEO
Project description:Lactic acidosis triggers starvation response with distinct metabolic profiles
| PRJNA120737 | ENA
Project description: Not available
| S-EPMC2937306 | biostudies-literature
Project description:In order to investigate the effect of MondoA loss on the expression of Myc-dependent genes, we performed a microarray analysis from RNAs isolated from TET21N cells expressing either control (siControl) or MondoA (siMondoA) siRNAs either with (NT) or without (Doxy) induced N-Myc expression. TET21N cells were grown in medium with either Doxy (Myc-Off) or No Treatment (Myc-On), then transiently transfected with either non-specific siRNA or MondoA siRNA in replicates. Cells were then lysed and RNA isolated.
2015-01-01 | E-GEOD-55538 | biostudies-arrayexpress
Project description:Acute lymphoblastic leukemia (ALL) is the most common childhood cancer. To identify novel candidates for targeted treatment of childhood ALL, we performed a comprehensive transcriptome analysis yielding a set of genes specifically overexpressed in ALL. Among them we identified MondoA - a transcription factor regulating glycolysis in response to glucose availability. Here, we confirm that MondoA is highly overexpressed ALL, whereas the MondoA paralog, MondoB, is not expressed. Expression studies revealed that MondoA is not regulated by glucose availability in leukemia cells, but by the presence of lactate. An in silico MondoA promoter analysis identified two methylation-prone CpG-islands and four conserved binding sites for runt-related transcription factor 1 (RUNX1). In fact, MondoA and RUNX1 are significantly coexpressed in leukemia and experimental blockage of DNA methylation leads to a further induction of MondoA. In addition, using microarray profiling, gene-set enrichment analysis and RNA interference we provide for the first time evidence that MondoA expression not only increases glucose catabolism, but also maintains a more immature ALL phenotype, which is associated with enhanced survival and clonogenicity of leukemia cells. These data hint to an important contribution of MondoA to leukemia aggressiveness validating MondoA as an attractive candidate for targeted treatment of ALL. Two nonsense shRNA expressing control Nalm6 clones and three MondoA shRNA expressing Nalm6 clones were subjected to microarray analysis.
2012-07-31 | E-GEOD-33967 | biostudies-arrayexpress