Similar Datasets
Project description:Blocking pyrimidine de novo synthesis via inhibiting Dihydroorotate dehydrogenase (DHODH) is clinically used to treat autoimmunity and to prevent the growth of rapidly dividing cells including activated T-cells. We identified a previously unrecognized resistance of precursors of memory T-cells to pyrimidine starvation. While the treatment effectively blocks effector T-cells, numbers, function and transcriptional profiles of memory T-cells and their precursors remain completely unaltered. We pinpoint this effect to a narrow time-window in the early T-cell expansion phase, when developing effector, but not memory T-cells are selectively vulnerable to pyrimidine starvation. This stems from a higher proliferative pace of early effector T-cells paired with lower pyrimidine synthesis capacity compared to memory precursors. This differential sensitivity constitutes a novel, drug-targetable checkpoint that efficiently diminishes effector T-cells without harming the memory compartment. We envision that knowledge of this pyrimidine synthesis-based cell fate-determining particularity opens up new means to safely manipulate effector T-cell responses.
2023-01-10 | GSE200359 | GEO
Project description:Blocking pyrimidine de novo synthesis via inhibiting Dihydroorotate dehydrogenase (DHODH) is clinically used to treat autoimmunity and to prevent the growth of rapidly dividing cells including activated T-cells. We identified a previously unrecognized resistance of precursors of memory T-cells to pyrimidine starvation. While the treatment effectively blocks effector T-cells, numbers, function and transcriptional profiles of memory T-cells and their precursors remain completely unaltered. We pinpoint this effect to a narrow time-window in the early T-cell expansion phase, when developing effector, but not memory T-cells are selectively vulnerable to pyrimidine starvation. This stems from a higher proliferative pace of early effector T-cells paired with lower pyrimidine synthesis capacity compared to memory precursors. This differential sensitivity constitutes a novel, drug-targetable checkpoint that efficiently diminishes effector T-cells without harming the memory compartment. We envision that knowledge of this pyrimidine synthesis-based cell fate-determining particularity opens up new means to safely manipulate effector T-cell responses.
2023-01-10 | GSE200358 | GEO
Project description:Blocking pyrimidine de novo synthesis via inhibiting Dihydroorotate dehydrogenase (DHODH) is clinically used to treat autoimmunity and to prevent the growth of rapidly dividing cells including activated T-cells. We identified a previously unrecognized resistance of precursors of memory T-cells to pyrimidine starvation. While the treatment effectively blocks effector T-cells, numbers, function and transcriptional profiles of memory T-cells and their precursors remain completely unaltered. We pinpoint this effect to a narrow time-window in the early T-cell expansion phase, when developing effector, but not memory T-cells are selectively vulnerable to pyrimidine starvation. This stems from a higher proliferative pace of early effector T-cells paired with lower pyrimidine synthesis capacity compared to memory precursors. This differential sensitivity constitutes a novel, drug-targetable checkpoint that efficiently diminishes effector T-cells without harming the memory compartment. We envision that knowledge of this pyrimidine synthesis-based cell fate-determining particularity opens up new means to safely manipulate effector T-cell responses.
2023-01-10 | GSE200488 | GEO
Project description:Pyrimidine de novo synthesis inhibition selectively blocks effector but not memory T-cell development.
| PRJNA824308 | ENA
Project description:Pyrimidine de novo synthesis inhibition selectively blocks effector but not memory T-cell development [SCRB-seq]
| PRJNA824310 | ENA
Project description:Pyrimidine de novo synthesis inhibition selectively blocks effector but not memory T-cell development [bulk RNA-seq]
| PRJNA824311 | ENA
Project description:Pyrimidine de novo synthesis inhibition selectively blocks effector but not memory T-cell development [scRNA-Seq 10x]
| PRJNA824806 | ENA
Project description:The use of stable isotope labeling has revolutionized NMR studies of nucleic acids, and there is a need for methods of incorporation of specific isotope labels to facilitate specific NMR experiments and applications. Enzymatic synthesis offers an efficient and flexible means to synthesize nucleoside triphosphates from a variety of commercially available specifically labeled precursors, permitting isotope labeling of RNAs prepared by in vitro transcription. Here, we recapitulate de novo pyrimidine biosynthesis in vitro, using recombinantly expressed enzymes to perform efficient single-pot syntheses of UTP and CTP that bear a variety of stable isotope labeling patterns. Filtered NMR experiments on (13)C, (15)N, (2)H-labeled HIV-2 TAR RNA demonstrate the utility and value of this approach. This flexible enzymatic synthesis will make implementing detailed and informative RNA stable isotope labeling schemes substantially more cost-effective and efficient, providing advanced tools for the study of structure and dynamics of RNA molecules.
| S-EPMC3134529 | biostudies-literature
Project description:The zebrafish perplexed mutation disrupts cell proliferation and differentiation during retinal development. In addition, growth and morphogenesis of the tectum, jaw, and pectoral fins are also affected. Positional cloning was used to identify a mutation in the carbamoyl-phosphate synthetase2-aspartate transcarbamylase-dihydroorotase (cad) gene as possibly causative of the perplexed mutation and this was confirmed by gene knockdown and pyrimidine rescue experiments. CAD is required for de novo biosynthesis of pyrimidines that are required for DNA, RNA, and UDP-dependent protein glycosylation. Developmental studies of several vertebrate species showed high levels of cad expression in tissues where mutant phenotypes were observed. Confocal time-lapse analysis of perplexed retinal cells in vivo showed a near doubling of the cell cycle period length. We also compared the perplexed mutation with mutations that affect either DNA synthesis or UDP-dependent protein glycosylation. Cumulatively, our results suggest an essential role for CAD in facilitating proliferation and differentiation events in a tissue-specific manner during vertebrate development. Both de novo DNA synthesis and UDP-dependent protein glycosylation are important for the perplexed phenotypes.
| S-EPMC1449754 | biostudies-literature
Project description:Cancer cells hijack and remodel existing metabolic pathways for their benefit. Argininosuccinate synthase (ASS1) is a urea cycle enzyme that is essential in the conversion of nitrogen from ammonia and aspartate to urea. A decrease in nitrogen flux through ASS1 in the liver causes the urea cycle disorder citrullinaemia. In contrast to the well-studied consequences of loss of ASS1 activity on ureagenesis, the purpose of its somatic silencing in multiple cancers is largely unknown. Here we show that decreased activity of ASS1 in cancers supports proliferation by facilitating pyrimidine synthesis via CAD (carbamoyl-phosphate synthase 2, aspartate transcarbamylase, and dihydroorotase complex) activation. Our studies were initiated by delineating the consequences of loss of ASS1 activity in humans with two types of citrullinaemia. We find that in citrullinaemia type I (CTLN I), which is caused by deficiency of ASS1, there is increased pyrimidine synthesis and proliferation compared with citrullinaemia type II (CTLN II), in which there is decreased substrate availability for ASS1 caused by deficiency of the aspartate transporter citrin. Building on these results, we demonstrate that ASS1 deficiency in cancer increases cytosolic aspartate levels, which increases CAD activation by upregulating its substrate availability and by increasing its phosphorylation by S6K1 through the mammalian target of rapamycin (mTOR) pathway. Decreasing CAD activity by blocking citrin, the mTOR signalling, or pyrimidine synthesis decreases proliferation and thus may serve as a therapeutic strategy in multiple cancers where ASS1 is downregulated. Our results demonstrate that ASS1 downregulation is a novel mechanism supporting cancerous proliferation, and they provide a metabolic link between the urea cycle enzymes and pyrimidine synthesis.
| S-EPMC4655447 | biostudies-literature