Inhibiting neddylation modification alters mitochondrial morphology and reprograms energy metabolism in cancer cells.
Ontology highlight
ABSTRACT:
SUBMITTER: Zhou Q
PROVIDER: S-EPMC6478410 | biostudies-literature | 2019 Feb
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Dysfunctional mitochondria and generation of reactive oxygen species (ROS) promote chronic diseases, which have spurred interest in the molecular mechanisms underlying these conditions. Previously, we have demonstrated that disruption of post-translational modification of proteins with ?-linked N-acetylglucosamine (O-GlcNAcylation) via overexpression of the O-GlcNAc-regulating enzymes O-GlcNAc transferase (OGT) or O-GlcNAcase (OGA) impairs mitochondrial function. Here, we report that sustained alterations in O-GlcNAcylation either by pharmacological or genetic manipulation also alter metabolic function. Sustained O-GlcNAc elevation in SH-SY5Y neuroblastoma cells increased OGA expression and reduced cellular respiration and ROS generation. Cells with elevated O-GlcNAc levels had elongated mitochondria and increased mitochondrial membrane potential, and RNA-sequencing analysis indicated transcriptome reprogramming and down-regulation of the NRF2-mediated antioxidant response. Sustained O-GlcNAcylation in mouse brain and liver validated the metabolic phenotypes observed in the cells, and OGT knockdown in the liver elevated ROS levels, impaired respiration, and increased the NRF2 antioxidant response. Moreover, elevated O-GlcNAc levels promoted weight loss and lowered respiration in mice and skewed the mice toward carbohydrate-dependent metabolism as determined by indirect calorimetry. In summary, sustained elevation in O-GlcNAcylation coupled with increased OGA expression reprograms energy metabolism, a finding that has potential implications for the etiology, development, and management of metabolic diseases.
| S-EPMC5592672 | biostudies-literature
Project description:The bacterial effector protein cycle inhibiting factor (CIF) converts glutamine 40 of NEDD8 to glutamate (Q40E), causing cytopathic effects and inhibiting cell proliferation. Although these have been attributed to blocking the functions of cullin-RING ubiquitin ligases, how CIF modulates NEDD8-dependent signaling is unclear. Here we use conditional NEDD8-dependent yeast to explore the effects of CIF on cullin neddylation. Although CIF causes cullin deneddylation and the generation of free NEDD8 Q40E, inhibiting the COP9 signalosome (CSN) allows Q40E to form only on NEDD8 attached to cullins. In the presence of the CSN, NEDD8 Q40E is removed from cullins more rapidly than NEDD8, leading to a decrease in steady-state cullin neddylation. As NEDD8 Q40E is competent for cullin conjugation in the absence of functional CSN and with overexpression of the NEDD8 ligase Dcn1, our data are consistent with NEDD8 deamidation causing enhanced deneddylation of cullins by the CSN. This leads to a dramatic change in the extent of activated cullin-RING ubiquitin ligases.
| S-EPMC3663497 | biostudies-literature
Project description:Mitochondria, the major organelles that produce energy for cell survival and function, dynamically change their morphology via fusion and fission, a process called mitochondrial dynamics. The details of the underlying mechanism of mitochondrial dynamics have not yet been elucidated. Here, we aimed to investigate the function of mitochondrial fission genes in embryonic stem cells (ESCs). To this end, we generated homozygous knockout ESC lines, namely, Fis1-/-, Mff-/-, and Dnm1l-/- ESCs, using the CRISPR-Cas9 system. Interestingly, the Fis1-/-, Mff-/-, and Dnm1l-/- ESCs showed normal morphology, self-renewal, and the ability to differentiate into all three germ layers in vitro. However, transmission electron microscopy showed a significant increase in the cytoplasm to nucleus ratio and mitochondrial elongation in Dnm1l-/- ESCs, which was due to incomplete fission. To assess the change in metabolic energy, we analyzed oxidative phosphorylation (OXPHOS), glycolysis, and the intracellular ATP concentration. The ESC knockout lines showed an increase in OXPHOS, decrease in glycolysis, and an increase in intracellular ATP concentration, which was related to mitochondrial elongation. In particular, the Dnm1l knockout most significantly affected mitochondrial morphology, energy metabolism, and ATP production in ESCs. Furthermore, RNA sequencing and gene ontology analysis showed that the differentially expressed genes in Mff-/- ESCs were distinct from those in Dnm1l-/- or Fis1-/- ESCs. In total, five metabolism-related genes, namely, Aass, Cdo1, Cyp2b23, Nt5e, and Pck2, were expressed in all three knockout ESC lines, and three of them were associated with regulation of ATP generation.
| S-EPMC7286981 | biostudies-literature
Project description:Here we aimed to investigate the function of mitochondrial fission genes in embryonic stem cells (ESCs). Homozygous knockout ESC lines, namely, Fis1-/- , Mff-/- , and Dnm1l-/- ESCs, were generated using the CRISPR-Cas9 system. After then, we analyzed whole genome expression profile for characterizing cellular responses by incomplete mitochondrial fission.
2020-04-21 | GSE148959 | GEO
Project description:Fast-growing tumors satisfy their bioenergetic needs by supplementing glucose with alternative carbon sources. Cancer stem cells are the most versatile and robust cells within malignant tumors. They avoid potentially lethal metabolic and other types of stress through flexible reprogramming of relevant pathways, but it has remained unclear whether alternative carbon sources are important for the maintenance of their tumor-propagating ability. Here we assessed the ability of glycolytic and oxidative murine glioma stem cells (GSCs) to grow in an ultralow glucose medium. Sphere formation assays revealed that exogenous lactate and acetate reversed the growth impairment of oxidative GSCs in such medium. Extracellular flux analysis showed that lactate supported oxygen consumption in these cells, whereas metabolomics analysis revealed that it increased the intracellular levels of tricarboxylic acid cycle intermediates, ATP, and GTP as well as increased adenylate and guanylate charge. Lactate also reversed the depletion of choline apparent in the glucose-deprived cells as well as reprogrammed phospholipid and fatty acid biosynthesis. This metabolic reprogramming was associated with a more aggressive phenotype of intracranial tumors formed by lactate-treated GSCs. Our results thus suggest that lactate is an important alternative energetic and biosynthetic substrate for oxidative GSCs, and that it sustains their growth under conditions of glucose deprivation.
| S-EPMC8158503 | biostudies-literature
Project description:In 2020, lung cancer remains the most diagnosed entity among men and third most among women, causing approximately 1.8 million deaths worldwide with an estimated 31.5% of new cases in men and 14.6% in women, respectively (1). Moreover, metastasized non-small cell lung cancer (NSCLC) continues to be one of the cancer entities with the worst prognosis as well as disease-free and overall survival despite the recent introduction of immunotherapy, with the patients’ 5-year-survival rate ranging still only between 10-20% (1). The development of cancer and metastasis is considered a multi-step process in which many factors are the topic of ongoing investigation. Thus, the identification of novel markers and targets, which are involved in disease progression, is an essential step in improving the survival of lung cancer patients. Previously, we identified HECT and RLD domain containing E3 ubiquitin protein ligase 5 (HERC5) gene as the main target gene on 4q (6). Loss of 4q has been associated with advanced disease stage and worse prognosis in several cancer entities including lung, colorectal, pancreatic, and hepatocellular cancer (2–5). We showed that in NSCLC, HERC5 downregulation via promoter hypermethylation leads to an increase in disseminated tumor cells (DTCs) and occurrence of brain metastases in NSCLC as well as poorer overall survival (OS) (6). In hepatocellular cancer, low mRNA expression levels of HERC5 could similarly be correlated with shorter OS, which led to immune evasion by indirectly increasing infiltration by regulatory T-cells (5). It was thus postulated that HERC5 might serve as a novel metastasis suppressor gene. Originally described in the context of innate immune responses, HERC5 is known to serve as the cellular main E3 ligase of ubiquitin-like modifier interferon-stimulated gene 15 (ISG15) (7,8), thereby catalyzing the transfer of ISG15 onto target proteins – a process called ISGylation. ISGylation is not only an important primary defense mechanism against viruses and other pathogens (9,10), but also associated with various diseases such as immunodeficiencies, neurodegenerative disorders and different types of cancer (11–14). Lately, energy metabolism has been proven to have a strong influence on tumorigenesis and metastasization (15–17). Given the enhanced energy demand of highly proliferating cells, tumor cells can undergo a change in energy consumption mechanisms – such as the well-described Warburg-effect, leading to a switch between ATP production through glycolysis rather than oxidative phosphorylation (OXPHOS) (18). Despite the lower yield in ATP through glycolysis, malignant cells often prefer this pathway even in the presence of oxygen, leading to an increase in metabolic byproducts which are necessary for the elevated demand of metabolites required due to their high proliferation rates (15,16). Deregulation of ISG15 have been linked to dysfunctional mitochondria as well as altered OXPHOS activity (19–22). In this study, we aimed at further elucidating the potential metastasis suppressing role of HERC5 in NSCLC. We therefore assessed the malignant potential of HERC5 loss in in vitro and in vivo NSCLC models and could confirm its capacity to transform NSCLC cells both in vitro and in vivo into a more aggressive phenotype. We furthermore performed mass spectrometry analyses to identify the main pathways altered by differential HERC5 expression in modified NSCLC cell lines and could show that HERC5 has an influence on mitochondrial composition, and energy metabolism pathways such as OXPHOS, leading to better adaptation and survival under prolonged inhibition of oxidative phosphorylation.
2024-05-24 | PXD045563 | Pride
Project description:Introduced about a century ago, suramin remains a frontline drug for the management of early-stage East African trypanosomiasis (sleeping sickness). Cellular entry into the causative agent, the protozoan parasite Trypanosoma brucei, occurs through receptor-mediated endocytosis involving the parasite's invariant surface glycoprotein 75 (ISG75), followed by transport into the cytosol via a lysosomal transporter. The molecular basis of the trypanocidal activity of suramin remains unclear, but some evidence suggests broad, but specific, impacts on trypanosome metabolism (i.e. polypharmacology). Here we observed that suramin is rapidly accumulated in trypanosome cells proportionally to ISG75 abundance. Although we found little evidence that suramin disrupts glycolytic or glycosomal pathways, we noted increased mitochondrial ATP production, but a net decrease in cellular ATP levels. Metabolomics highlighted additional impacts on mitochondrial metabolism, including partial Krebs' cycle activation and significant accumulation of pyruvate, corroborated by increased expression of mitochondrial enzymes and transporters. Significantly, the vast majority of suramin-induced proteins were normally more abundant in the insect forms compared with the blood stage of the parasite, including several proteins associated with differentiation. We conclude that suramin has multiple and complex effects on trypanosomes, but unexpectedly partially activates mitochondrial ATP-generating activity. We propose that despite apparent compensatory mechanisms in drug-challenged cells, the suramin-induced collapse of cellular ATP ultimately leads to trypanosome cell death.
| S-EPMC7294092 | biostudies-literature
Project description:Endoparasitism by gall-forming insects dramatically alters the plant phenotype by altering growth patterns and modifying plant organs in ways that appear to directly benefit the gall former. Because these morphological and physiological changes are linked to the presence of the insect, the induced phenotype is said to function as an extension of the parasite, albeit by unknown mechanisms. Here we report the gall-forming aphid-like parasite phylloxera, Daktulosphaira vitifoliae, induces stomata on the adaxial surface of grape leaves where stomata typically do not occur. We characterized the function of the phylloxera-induced stomata by tracing transport of assimilated carbon. Because induction of stomata suggests a significant manipulation of primary metabolism, we also characterized the gall transcriptome to infer the level of global reconfiguration of primary metabolism and the subsequent changes in downstream secondary metabolism. Phylloxera feeding induced stomata formation in proximity to the insect and promoted the assimilation and importation of carbon into the gall. Gene expression related to water, nutrient, and mineral transport; glycolysis; and fermentation increased in leaf-gall tissues. This shift from an autotrophic to a heterotrophic profile occurred concurrently with decreased gene expression for nonmevalonate and terpenoid synthesis and increased gene expression in shikimate and phenylpropanoid biosynthesis, secondary metabolite systems that alter defense status in grapes. These functional insect-induced stomata thus comprise part of an extended phenotype, whereby D. vitifoliae globally reprograms grape leaf development to alter patterns of primary metabolism, nutrient mobilization, and defense investment in favor of the galling habit.
| S-EPMC3799386 | biostudies-literature
Project description:Metabolic reprogramming is implicated in macrophage activation, but the underlying mechanisms are poorly understood. Here, we demonstrate that the NOTCH1 pathway dictates activation of M1 phenotypes in isolated mouse hepatic macrophages (HMacs) and in a murine macrophage cell line by coupling transcriptional upregulation of M1 genes with metabolic upregulation of mitochondrial oxidative phosphorylation and ROS (mtROS) to augment induction of M1 genes. Enhanced mitochondrial glucose oxidation was achieved by increased recruitment of the NOTCH1 intracellular domain (NICD1) to nuclear and mitochondrial genes that encode respiratory chain components and by NOTCH-dependent induction of pyruvate dehydrogenase phosphatase 1 (Pdp1) expression, pyruvate dehydrogenase activity, and glucose flux to the TCA cycle. As such, inhibition of the NOTCH pathway or Pdp1 knockdown abrogated glucose oxidation, mtROS, and M1 gene expression. Conditional NOTCH1 deficiency in the myeloid lineage attenuated HMac M1 activation and inflammation in a murine model of alcoholic steatohepatitis and markedly reduced lethality following endotoxin-mediated fulminant hepatitis in mice. In vivo monocyte tracking further demonstrated the requirement of NOTCH1 for the migration of blood monocytes into the liver and subsequent M1 differentiation. Together, these results reveal that NOTCH1 promotes reprogramming of mitochondrial metabolism for M1 macrophage activation.
| S-EPMC4396469 | biostudies-literature
Project description:Beneficial associations between plants and microbes play an important role in both natural and agricultural ecosystems. For example, associations between fungi of the genus Epichloë, and cool-season grasses are known for their ability to increase resistance to insect pests, fungal pathogens and drought. However, little is known about the molecular changes induced by endophyte infection. To study the impact of endophyte infection, we compared the expression profiles, based on RNA sequencing, of perennial ryegrass infected with Epichloë festucae with noninfected plants. We show that infection causes dramatic changes in the expression of over one third of host genes. This is in stark contrast to mycorrhizal associations, where substantially fewer changes in host gene expression are observed, and is more similar to pathogenic interactions. We reveal that endophyte infection triggers reprogramming of host metabolism, favouring secondary metabolism at a cost to primary metabolism. Infection also induces changes in host development, particularly trichome formation and cell wall biogenesis. Importantly, this work sheds light on the mechanisms underlying enhanced resistance to drought and super-infection by fungal pathogens provided by fungal endophyte infection. Finally, our study reveals that not all beneficial plant-microbe associations behave the same in terms of their effects on the host.
| S-EPMC5049663 | biostudies-literature