Dataset Information

Metabolic fate of endogenous molecular damage: Urinary glutathione conjugates of DNA-derived base propenals as markers of inflammation.

ABSTRACT: Although mechanistically linked to disease, cellular molecules damaged by endogenous processes have not emerged as significant biomarkers of inflammation and disease risk, due in part to poor understanding of their pharmacokinetic fate from tissue to excretion. Here, we use systematic metabolite profiling to define the fate of a common DNA oxidation product, base propenals, to discover such a biomarker. Based on known chemical reactivity and metabolism in liver cell extracts, 15 candidate metabolites were identified for liquid chromatography-coupled tandem mass spectrometry (LC-MS/MS) quantification in urine and bile of rats treated with thymine propenal (Tp). Analysis of urine revealed three metabolites (6% of Tp dose): thymine propenoate and two mercapturate derivatives of glutathione conjugates. Bile contained an additional four metabolites (22% of Tp dose): cysteinylglycine and cysteine derivatives of glutathione adducts. A bis-mercapturate was observed in urine of untreated rats and increased approximately three- to fourfold following CCl4-induced oxidative stress or treatment with the DNA-cleaving antitumor agent, bleomycin. Systematic metabolite profiling thus provides evidence for a metabolized DNA damage product as a candidate biomarker of inflammation and oxidative stress in humans.

SUBMITTER: Jumpathong W

PROVIDER: S-EPMC4568270 | biostudies-literature | 2015 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Metabolic fate of endogenous molecular damage: Urinary glutathione conjugates of DNA-derived base propenals as markers of inflammation.

Jumpathong Watthanachai W Chan Wan W Taghizadeh Koli K Babu I Ramesh IR Dedon Peter C PC

Proceedings of the National Academy of Sciences of the United States of America 20150817 35

Although mechanistically linked to disease, cellular molecules damaged by endogenous processes have not emerged as significant biomarkers of inflammation and disease risk, due in part to poor understanding of their pharmacokinetic fate from tissue to excretion. Here, we use systematic metabolite profiling to define the fate of a common DNA oxidation product, base propenals, to discover such a biomarker. Based on known chemical reactivity and metabolism in liver cell extracts, 15 candidate metabo ...[more]

PMID: 26283391

Similar Datasets

Project description:BackgroundRenal disease in canine leishmaniosis is of great importance owing to increased risk of mortality. In human visceral leishmaniosis, monocyte chemoattractant protein-1 (MCP-1) has been used as a marker of renal damage and inflammation. The purpose of this study was first to determine the serum MCP-1 and urinary MCP-1-to-creatinine ratio (uMCP-1/Cr) in healthy dogs and dogs with leishmaniosis at diagnosis, and second to determine whether these markers can differentiate disease severity at diagnosis.MethodsIn total, 19 healthy seronegative dogs and 38 dogs with leishmaniosis were included in the study. Dogs with leishmaniosis were classified as LeishVet clinical staging and as International Renal Interest Society (IRIS) staging. Serum and urinary MCP-1 concentrations were measured with an enzyme-linked immunosorbent assay. A receiver operating characteristic (ROC) curve determined disease severity at diagnosis between two LeishVet groups (Stage II versus stage III and IV).ResultsDogs in Leishvet stages IIb, III, and IV had a median serum MCP-1 and uMCP-1/Cr concentration higher than healthy dogs (P < 0.0001). No statistical differences were found in serum MCP-1 and uMCP-1/Cr between dogs in LeishVet stage IIa and healthy dogs. The dogs in LeishVet stage IV had significantly higher serum MCP-1 and uMCP-1/Cr compared with the dogs in LeishVet stage IIa (P < 0.0001). Serum MCP-1 and uMCP-1 were significantly higher in dogs in IRIS stage I and II + III + IV compared with healthy dogs. Dogs stage II + III + IV of IRIS had a significantly higher serum MCP-1 compared with dogs in IRIS stage I (P < 0.0001). The area under the ROC curve for serum MCP-1 was 0.78 [95% confidence interval (CI) 0.64-0.93] and for uMCP-1/Cr it was 0.86 (95% CI, 0.74-0.99). The optimal cutoff value for serum MCP-1 and uMCP-1/Cr was 336.85 pg/ml (sensitivity of 79% and specificity of 68%) and 6.89 × 10-7 (sensitivity of 84% and specificity of 79%), respectively.ConclusionsSerum MCP-1 and uMCP-1/Cr are increased in dogs with leishmaniosis compared with healthy dogs, suggesting the presence of inflammation and renal injury. Serum MCP-1 and uMCP-1/Cr were more elevated in the advanced stages of the disease compared with the moderate stages and, therefore, can be markers of the severity of the disease process.

Project description:Glutathione (GSH) is the archetypal antioxidant, and plays a central role in the protection of the ocular lens from cataract formation. High levels of GSH are maintained in the transparent lens, but with advancing age, GSH levels fall in the lens nucleus relative to outer cortical cells, thereby exposing the nucleus of the lens to the damaging effects of oxygen radicals, which ultimately leads to age-related nuclear (ARN) cataract. Under normal conditions, GSH also forms endogenous conjugates to detoxify the lens of reactive cellular metabolites and to maintain cell homeostasis. Due to the intrinsic gradient of lens fibre cell age, the lens contains distinct regions with different metabolic requirements for GSH. To investigate the impact of fibre cell and lens aging on the varied roles that GSH plays in the lens, we have utilised high mass resolution MALDI mass spectrometry profiling and imaging analysis of lens tissue sections. High Dynamic Range (HDR)-MALDI FTICR mass spectrometry was used as an initial screening method to detect regional differences in lens metabolites from normal bovine lenses and in those subjected to hyperbaric oxygen as a model of lens aging. Subsequent MALDI imaging analysis was used to spatially map GSH and its endogenous conjugates throughout all lenses. Accurate mass measurement by MALDI FTICR analysis and LC-MS/MS mass spectrometry of lens region homogenates were subsequently used to identify endogenous GSH conjugates. While the distribution and relative abundance of GSH-related metabolic intermediates involved in detoxification pathways remained relatively unchanged upon HBO treatment, those involved in its antioxidant function were altered under conditions of oxidative stress. For example, reduced glutathione levels were decreased in the lens cortex while oxidised glutathione levels were elevated in the lens outer cortex upon HBO treatment. Interestingly, cysteineglutathione disulfide, was detected in the inner cortex of the normal lens, but was greatly decreased in the HBO-treated lenses. These results contribute to our understanding of the multiple roles that GSH plays in maintenance of lens transparency and in the age-related metabolic changes that lead to lens cataract formation.

Project description:The safener fenclorim (4,6-dichloro-2-phenylpyrimidine) increases tolerance to chloroacetanilide herbicides in rice by enhancing the expression of detoxifying glutathione S-transferases (GSTs). Fenclorim also enhances GSTs in Arabidopsis thaliana, and while investigating the functional significance of this induction in suspension cultures, we determined that these enzymes glutathionylated the safener. The resulting S-(fenclorim)-glutathione conjugate was sequentially processed to S-(fenclorim)-gamma-glutamyl-cysteine and S-(fenclorim)-cysteine (FC), the latter accumulating in both the cells and the medium. FC was then either catabolized to 4-chloro-6-(methylthio)-phenylpyrimidine (CMTP) or N-acylated with malonic acid. These cysteine derivatives had distinct fates, with the enzymes responsible for their formation being induced by fenclorim and FC. Fenclorim-N-malonylcysteine was formed from FC by the action of a malonyl-CoA-dependent N-malonyltransferase. A small proportion of the fenclorim-N-malonylcysteine then underwent decarboxylation to yield a putative S-fenclorim-N-acetylcysteine intermediate, which underwent a second round of GST-mediated S-glutathionylation and subsequent proteolytic processing. The formation of CMTP was catalyzed by the concerted action of a cysteine conjugate beta-lyase and an S-methyltransferase, with the two activities being coordinately regulated. Although the fenclorim conjugates tested showed little GST-inducing activity in Arabidopsis, the formation of CMTP resulted in metabolic reactivation, with the product showing good enhancing activity. In addition, CMTP induced GSTs and herbicide-safening activity in rice. The bioactivated CMTP was in turn glutathione-conjugated and processed to a malonyl cysteine derivative. These results reveal the surprisingly complex set of competing catabolic reactions acting on xenobiotics entering the S-glutathionylation pathway in plants, which can result in both detoxification and bioactivation.

Project description:Spherical nucleic acid (SNA) nanoparticle conjugates are a class of bionanomaterials that are extremely potent in many biomedical applications. Their unique ability to enter multiple mammalian cell types as single-entity agents arises from their novel three-dimensional architecture, which consists of a dense shell of highly oriented oligonucleotides chemically attached typically to a gold nanoparticle core. This architecture allows SNAs to engage certain cell surface receptors to facilitate entry. Here, we report studies aimed at determining the intracellular fate of SNAs and the trafficking events that occur inside C166 mouse endothelial cells after cellular entry. We show that SNAs traffic through the endocytic pathway into late endosomes and reside there for up to 24 h after incubation. Disassembly of oligonucleotides from the nanoparticle core is observed 16 h after cellular entry, most likely due to degradation by enzymes such as DNase II localized in late endosomes. Our observations point to these events being likely independent of core composition and treatment conditions, and they do not seem to be particularly dependent upon oligonucleotide sequence. Significantly and surprisingly, the SNAs do not enter the lysosomes under the conditions studied. To independently track the fate of the particle core and the fluorophore-labeled oligonucleotides that comprise its shell, we synthesized a novel class of quantum dot SNAs to determine that as the SNA structures are broken down over the 24 h time course of the experiment, the oligonucleotide fragments are recycled out of the cell while the nanoparticle core is not. This mechanistic insight points to the importance of designing and synthesizing next-generation SNAs that can bypass the degradation bottleneck imposed by their residency in late endosomes, and it also suggests that such structures might be extremely useful for endosomal signaling pathways by engaging receptors that are localized within the endosome.

Dataset Information

Metabolic fate of endogenous molecular damage: Urinary glutathione conjugates of DNA-derived base propenals as markers of inflammation.

Publications

Metabolic fate of endogenous molecular damage: Urinary glutathione conjugates of DNA-derived base propenals as markers of inflammation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets