Dataset Information

The CPT1a inhibitor, etomoxir induces severe oxidative stress at commonly used concentrations.

ABSTRACT: Etomoxir (ETO) is a widely used small-molecule inhibitor of fatty acid oxidation (FAO) through its irreversible inhibitory effects on the carnitine palmitoyl-transferase 1a (CPT1a). We used this compound to evaluate the role of fatty acid oxidation in rapidly proliferating T cells following costimulation through the CD28 receptor. We show that ETO has a moderate effect on T cell proliferation with no observable effect on memory differentiation, but a marked effect on oxidative metabolism. We show that this oxidative metabolism is primarily dependent upon glutamine rather than FAO. Using an shRNA approach to reduce CPT1a in T cells, we further demonstrate that the inhibition of oxidative metabolism in T cells by ETO is independent of its effects on FAO at concentrations exceeding 5??M. Concentrations of ETO above 5??M induce acute production of ROS with associated evidence of severe oxidative stress in proliferating T cells. In aggregate, these data indicate that ETO lacks specificity for CTP1a above 5??M, and caution should be used when employing this compound for studies in cells due to its non-specific effects on oxidative metabolism and cellular redox.

SUBMITTER: O'Connor RS

PROVIDER: S-EPMC5908836 | biostudies-other | 2018 Apr

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

The CPT1a inhibitor, etomoxir induces severe oxidative stress at commonly used concentrations.

O'Connor Roddy S RS Guo Lili L Ghassemi Saba S Snyder Nathaniel W NW Worth Andrew J AJ Weng Liwei L Kam Yoonseok Y Philipson Benjamin B Trefely Sophie S Nunez-Cruz Selene S Blair Ian A IA June Carl H CH Milone Michael C MC

Scientific reports 20180419 1

Etomoxir (ETO) is a widely used small-molecule inhibitor of fatty acid oxidation (FAO) through its irreversible inhibitory effects on the carnitine palmitoyl-transferase 1a (CPT1a). We used this compound to evaluate the role of fatty acid oxidation in rapidly proliferating T cells following costimulation through the CD28 receptor. We show that ETO has a moderate effect on T cell proliferation with no observable effect on memory differentiation, but a marked effect on oxidative metabolism. We sho ...[more]

PMID: 29674640

Similar Datasets

Project description:BACKGROUND:Hypernatraemia is common in inpatients and is associated with substantial morbidity. Its differential diagnosis is challenging, and delayed treatment may have devastating consequences. The most important hormone for the regulation of water homeostasis is arginine vasopressin, and copeptin, the C-terminal portion of the precursor peptide of arginine vasopressin, might be a reliable new parameter with which to assess the underlying cause of hypernatraemia. METHODS:In this prospective, multicentre, observational study conducted in two tertiary referral centres in Switzerland, 92 patients with severe hyperosmolar hypernatraemia (Na+?>?155 mmol/L) were included. After a standardised diagnostic evaluation, the underlying cause of hypernatraemia was identified and copeptin levels were measured. RESULTS:The most common aetiology of hypernatraemia was dehydration (DH) (n?=?65 [71%]), followed by salt overload (SO) (n?=?20 [22%]), central diabetes insipidus (CDI) (n?=?5 [5%]) and nephrogenic diabetes insipidus (NDI) (n?=?2 [2%]). Low urine osmolality was indicative for patients with CDI and NDI (P?<?0.01). Patients with CDI had lower copeptin levels than patients with DH or SO (both P?<?0.01) or those with NDI. Copeptin identified CDI with an AUC of 0.99 (95% CI 0.97-1.00), and a cut-off value???4.4pmol/L showed a sensitivity of 100% and a specificity of 99% to predict CDI. Similarly, urea values were lower in CDI than in DH or SO (P?<?0.05 and P?<?0.01, respectively) or NDI. The AUC for diagnosing CDI was 0.98 (95% CI 0.96-1.00), and a cut-off value?<?5.05 mmol/L showed high specificity and sensitivity for the diagnosis of CDI (98% and 100%, respectively). Copeptin and urea could not differentiate hypernatraemia induced by DH from that induced by SO (P?=?0.66 and P?=?0.30, respectively). CONCLUSIONS:Copeptin and urea reliably identify patients with CDI and are therefore helpful tools for therapeutic management in patients with severe hypernatraemia. TRIALS REGISTRATION:ClinicalTrials.gov, NCT01456533 . Registered on 20 October 2011.

Project description:Oxidative stress (OS) results from genetic defects or stressful environmental challenges that cause unchecked production of reactive oxygen species (ROS). OS has been implicated in many diseases due to its wide ranging damage to nucleic acids, proteins and lipids. Using Halobacterium salinarum NRC-1, an extremophile that thrives under conditions of excessive OS, we have constructed a systems model for oxidative stress response (OSR) by integrating transcriptional changes induced by treatments with H2O2 and paraquat, functional associations inferred through comparative genomics, and de novo discovered cis-regulatory motifs. Together with phenotypic analysis of mutant strains this has revealed a multi-tiered OS management program to transcriptionally coordinate three peroxidase/catalase enzymes, two superoxide dismutases, production of rhodopsins, carotenoids, and gas vesicles, metal trafficking, and various other aspects of metabolism. Remarkably, a significant fraction of this OSR was accurately recapitulated by a model that was previously constructed from cellular responses to diverse environmental perturbations –this constitutes the general stress response component. Notwithstanding this observation, comparison of the two models has identified the coordination of frontline defense and repair systems by regulatory mechanisms that are triggered uniquely by severe OS and not by other environmental stressors, including sub-inhibitory levels of redox-active metals, extreme changes in oxygen tension, and a sub-lethal dose of g rays. Mid-log phase cultures of H. salinarum NRC-1 (2 biological replicates) grown in flasks were treated with either sub-lethal concentrations of 25mM H2O2 or 4mM PQ and incubated with shaking for up to 240 min. For each treatment, two time courses were run to determine the transcriptional responses to (1) constant stress and (2) recovery of H. salinarum NRC-1 to H2O2 and PQ. During constant stress, culture aliquots (~4ml) were collected over a time course (-1, 5, 10, 20, 40, 80 and 160 minutes), centrifuged (16000g, 90 seconds) and flash frozen. For recovery, cells were first treated for 2-hours with either 25 mM H2O2 or 4mM PQ, recovered by centrifugation, washed and re-suspended in CM. Cultures were returned to the incubator with shaking and samples were taken at 0, 10, 20, 30, 40, 50, 60, 120, and 240 minutes and processed as described previously. Analysis of temporal transcriptional changes (-1, 0, 5, 10, 20, 40, 80, 160 and 320m) to sub-inhibitory concentrations of PQ (0.25mM) was also characterized. Total RNA was prepared and labeled with Alexa547 and Alexa647 dyes. Intensities were normalized between the Alexa 546 and Alexa 647 channels by scaling all intensities in one channel such that the 75th percentile in each channel was made equal.

Dataset Information

The CPT1a inhibitor, etomoxir induces severe oxidative stress at commonly used concentrations.

Publications

The CPT1a inhibitor, etomoxir induces severe oxidative stress at commonly used concentrations.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure