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BMC Nephrology Apr 2023Chronic kidney disease (CKD) is a global public health issue. The diagnosis of CKD would be considerably enhanced by discovering novel biomarkers used to determine the...
BACKGROUND
Chronic kidney disease (CKD) is a global public health issue. The diagnosis of CKD would be considerably enhanced by discovering novel biomarkers used to determine the glomerular filtration rate (GFR). Small molecule metabolites related to kidney filtration function that might be utilized as biomarkers to measure GFR more accurately could be found via a metabolomics analysis of blood samples taken from individuals with varied glomerular filtration rates.
METHODS
An untargeted metabolomics study of 145 plasma samples was performed using ultrahigh-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The 145 samples were divided into four groups based on the patient's measured glomerular filtration rates (mGFRs) determined by the iohexol plasma clearance rate. The data were analyzed using random forest analyses and six other unique statistical analyses. Principal component analysis (PCA) was conducted using R software.
RESULTS
A large number of metabolites involved in various metabolic pathways changed significantly between groups with different GFRs. These included metabolites involved in tryptophan or pyrimidine metabolism. The top 30 metabolites that best distinguished between the four groups in a random forest plot analysis included 13 amino acids, 9 nucleotides, and 3 carbohydrates. A panel of metabolites (including hydroxyaparagine, pseudouridine, C-glycosyltryptophan, erythronate, N-acetylalanine, and 7-methylguanidine) for estimating GFR was selected for future testing in targeted analyses by combining the candidate lists with the six other statistical analyses. Both hydroxyasparagine and N,N-dimethyl-proline-proline are unique biomarkers shown to be inversely associated with kidney function that have not been reported previously. In contrast, 1,5-anhydroglucitol (1,5-AG) decreases with impaired renal function.
CONCLUSIONS
This global untargeted metabolomics study of plasma samples from patients with different degrees of renal function identified potential metabolite biomarkers related to kidney filtration. These novel potential metabolites provide more insight into the underlying pathophysiologic processes that may contribute to the progression of CKD, lead to improvements in the estimation of GFR and provide potential therapeutic targets to improve kidney function.
Topics: Humans; Glomerular Filtration Rate; Chromatography, Liquid; Tandem Mass Spectrometry; Renal Insufficiency, Chronic; Biomarkers
PubMed: 37085754
DOI: 10.1186/s12882-023-03147-9 -
Frontiers in Public Health 2022Gemcitabine and cisplatin serve as appropriate treatments for patients with cholangiocarcinoma (CCA). Our previous study using histoculture drug response assay (HDRA),...
Gemcitabine and cisplatin serve as appropriate treatments for patients with cholangiocarcinoma (CCA). Our previous study using histoculture drug response assay (HDRA), demonstrated individual response patterns to gemcitabine and cisplatin. The current study aimed to identify predictive biomarkers for gemcitabine and cisplatin sensitivity in tissues and sera from patients with CCA using metabolomics. Metabolic signatures of patients with CCA were correlated with their HDRA response patterns. The tissue metabolic signatures of patients with CCA revealed the inversion of the TCA cycle that is evident with increased levels of citrate and amino acid backbones as TCA cycle intermediates, and glucose which corresponds to cancer stem cell (CSC) properties. The protein expression levels of CSC markers were examined on tissues and showed the significantly inverse association with the responses of patients to cisplatin. Moreover, the elevation of ethanol level was observed in gemcitabine- and cisplatin-sensitive group. In serum, a lower level of glucose but a higher level of methylguanidine was observed in the gemcitabine-responders as non-invasive predictive biomarker for gemcitabine sensitivity. Collectively, our findings indicate that these metabolites may serve as the predictive biomarkers in clinical practice which not only predict the chemotherapy response in patients with CCA but also minimize the adverse effect from chemotherapy.
Topics: Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Biomarkers; Cholangiocarcinoma; Cisplatin; Deoxycytidine; Glucose; Humans; Gemcitabine
PubMed: 35223723
DOI: 10.3389/fpubh.2022.766023 -
Clinical Journal of the American... Aug 2022Adsorption of uremic solutes to activated carbon provides a potential means to limit dialysate volumes required for new dialysis systems. The ability of activated carbon...
BACKGROUND AND OBJECTIVES
Adsorption of uremic solutes to activated carbon provides a potential means to limit dialysate volumes required for new dialysis systems. The ability of activated carbon to take up uremic solutes has, however, not been adequately assessed.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS
Graded volumes of waste dialysate collected from clinical hemodialysis treatments were passed through activated carbon blocks. Metabolomic analysis assessed the adsorption by activated carbon of a wide range of uremic solutes. Additional experiments tested the ability of the activated carbon to increase the clearance of selected solutes at low dialysate flow rates.
RESULTS
Activated carbon initially adsorbed the majority, but not all, of 264 uremic solutes examined. Solute adsorption fell, however, as increasing volumes of dialysate were processed. Moreover, activated carbon added some uremic solutes to the dialysate, including methylguanidine. Activated carbon was particularly effective in adsorbing uremic solutes that bind to plasma proteins. dialysis experiments showed that introduction of activated carbon into the dialysate stream increased the clearance of the protein-bound solutes indoxyl sulfate and p-cresol sulfate by 77%±12% (mean±SD) and 73%±12%, respectively, at a dialysate flow rate of 200 ml/min, but had a much lesser effect on the clearance of the unbound solute phenylacetylglutamine.
CONCLUSIONS
Activated carbon adsorbs many but not all uremic solutes. Introduction of activated carbon into the dialysate stream increased the clearance of those solutes that it does adsorb.
Topics: Charcoal; Dialysis Solutions; Humans; Indican; Protein Binding; Renal Dialysis; Uremia
PubMed: 35835518
DOI: 10.2215/CJN.01610222 -
Neuropharmacology Dec 2019Poly(ADP-ribose) polymerase-1 (PARP1) is a ubiquitous nuclear enzyme that regulates DNA repair and genomic stability. In oxidative genotoxic conditions, PARP1 activity...
Poly(ADP-ribose) polymerase-1 (PARP1) is a ubiquitous nuclear enzyme that regulates DNA repair and genomic stability. In oxidative genotoxic conditions, PARP1 activity is enhanced significantly, leading to excessive depletion of nicotinamide adenine dinucleotide (NAD) and mitochondrial dysfunction. We hypothesized that PARP1-induced NAD depletion inhibits NAD-dependent sirtuin deacetylase activity, thereby interfering with the mitochondrial regulator, peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α). The DNA alkylator, N'-Nitro-N-nitroso-N-methylguanidine (MNNG), induced NAD depletion, inhibited sirtuin deacetylase activity and enhanced acetylation of PGC-1α. This was associated with reduced interaction between PGC-1α and nuclear respiratory factor 1 (NRF-1), which is a nuclear transcription factor that drives mitochondrial replication by regulating mitochondrial transcription factor A (TFAM). MNNG also reduced binding of NRF-1 to the tfam upstream promoter region and reduced TFAM mRNA, mitochondrial DNA copy number and respiratory function. MNNG effects were mitigated by PARP1 inhibition and genetic loss of function, by enhancing intracellular NAD levels, and with sirtuin (SIRT1) gain of function, supporting a mechanism dependent on PARP1 activity, NAD-depletion and SIRT1 inhibition. This and other work from our group supports a destructive sequelae of events related to PARP1-induced sirtuin inhibition and sirtuin-mediated regulation of transcription.
Topics: Acetylation; Animals; Cell Respiration; DNA, Mitochondrial; DNA-Binding Proteins; High Mobility Group Proteins; Methylnitronitrosoguanidine; Mice; Mitochondria; NAD; Neurons; Nuclear Respiratory Factor 1; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Poly (ADP-Ribose) Polymerase-1; Sirtuin 1; Transcription Factors; Transcription, Genetic
PubMed: 31487495
DOI: 10.1016/j.neuropharm.2019.107755 -
Beilstein Journal of Organic Chemistry 2021Chemical modifications have been extensively used for therapeutic oligonucleotides because they strongly enhance the stability against nucleases, binding affinity to the...
Chemical modifications have been extensively used for therapeutic oligonucleotides because they strongly enhance the stability against nucleases, binding affinity to the targets, and efficacy. We previously reported that oligonucleotides modified with an -methylguanidine-bridged nucleic acid (GuNA[Me]) bearing the thymine (T) nucleobase show excellent biophysical properties for applications in antisense technology. In this paper, we describe the synthesis of GuNA[Me] phosphoramidites bearing other typical nucleobases including adenine (A), guanine (G), and 5-methylcytosine (C). The phosphoramidites were successfully incorporated into oligonucleotides following the method previously developed for the GuNA[Me]-T-modified oligonucleotides. The binding affinity of the oligonucleotides modified with GuNA[Me]-A, -G, or -C toward the complementary single-stranded DNAs or RNAs was systematically evaluated. All of the GuNA[Me]-modified oligonucleotides were found to have a strong affinity for RNAs. These data indicate that GuNA[Me] could be a useful modification for therapeutic antisense oligonucleotides.
PubMed: 33747234
DOI: 10.3762/bjoc.17.54 -
Metabolites Nov 2020Autism spectrum disorder is a heterogeneous neurodevelopmental disease. Currently, no biomarker of this disease is known. Diagnosis is performed through observation,...
Autism spectrum disorder is a heterogeneous neurodevelopmental disease. Currently, no biomarker of this disease is known. Diagnosis is performed through observation, standardized behavioral scales, and interviews with parents. In practice, diagnosis is often delayed to the average age of four years or even more which adversely affects a child's perspective. A laboratory method allowing to detect the disorder at earlier stages is of a great need, as this could help the patients to start with treatment at a younger age, even prior to the clinical diagnosis. Recent evidence indicates that metabolomic markers should be considered as diagnostic markers, also serving for further differentiation and characterization of different subgroups of the autism spectrum. In this study, we developed an ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometry method for the simultaneous determination of six metabolites in human urine. These metabolites, namely methylguanidine, N-acetyl arginine, inosine, indole-3-acetic acid, indoxyl sulfate and xanthurenic acid were selected as potential biomarkers according to prior metabolomic studies. The analysis was carried out by means of reversed-phase liquid chromatography with gradient elution. Separation of the metabolites was performed on a Phenomenex Luna Omega Polar C18 (100 × 1.0 mm, 1.6 µm) column at a flow rate of 0.15 mL/min with acetonitrile/water 0.1% formic acid aqueous as the mobile phase. The analysis was performed on a group of children with autism spectrum disorder and age-matched controls. In school children, we have detected disturbances in the levels of oxidative stress markers connected to arginine and purine metabolism, namely methylguanidine and N-acetylargine. Also, products of gut bacteria metabolism, namely indoxyl sulfate and indole-3-acetic acid, were found to be elevated in the patients' group. We can conclude that this newly developed method is fast, sensitive, reliable, and well suited for the quantification of proposed markers.
PubMed: 33147863
DOI: 10.3390/metabo10110443 -
Heliyon Apr 2021Methylguanidine, an originator of carcinogenic methylnitrosourea, has been found in many animal meats and processed stored food often in high concentration. The present...
Methylguanidine, an originator of carcinogenic methylnitrosourea, has been found in many animal meats and processed stored food often in high concentration. The present study was designed to understand the multiple dose effect of N-methyl-N-nitrosourea (MNU), an end product of methylguanidine, in Swiss albino mice fertility as well as cancer induction. Accordingly, a total of five experimental groups of animal (female Swiss albino mice) were taken, considering group-I as vehicle control and group-II-V as treatment groups (whereas group-II-Vwere treated with single to quadruple doses of 50 mg/kg of MNU respectively in a three weeks interval). After accomplishment of MNU injection, each female mice was mated with male mice to check the fertility efficiency. The results of the study indicated that, mice treated with highest number of MNU doses were 42.85% less efficient in getting pregnant than the control mice. There were noted changes in body weight, food and water intake upon MNU-exposure compared to control group. A significant increase in cumulative weight of vital female organs like uterus and ovary were also observed in mice injected with quadruple doses of MNU (50 mg/kg) compared to control mice. The findings of the study suggest the direct effect of MNU in pregnancy, without any cancer incidence in the vital female organs of Swiss albino mice.
PubMed: 33912714
DOI: 10.1016/j.heliyon.2021.e06738 -
Cells Nov 2022This paper describes an untargeted NMR metabolomics study to identify potential intracellular donor-dependent and donor-independent metabolic markers of proliferation...
This paper describes an untargeted NMR metabolomics study to identify potential intracellular donor-dependent and donor-independent metabolic markers of proliferation and osteogenic differentiation of human adipose mesenchymal stem cells (hAMSCs). The hAMSCs of two donors with distinct proliferating/osteogenic characteristics were fully characterized regarding their polar endometabolome during proliferation and osteogenesis. An 18-metabolites signature (including changes in alanine, aspartate, proline, tyrosine, ATP, and ADP, among others) was suggested to be potentially descriptive of cell proliferation, independently of the donor. In addition, a set of 11 metabolites was proposed to compose a possible donor-independent signature of osteogenesis, mostly involving changes in taurine, glutathione, methylguanidine, adenosine, inosine, uridine, and creatine/phosphocreatine, choline/phosphocholine and ethanolamine/phosphocholine ratios. The proposed signatures were validated for a third donor, although they require further validation in a larger donor cohort. We believe that this proof of concept paves the way to exploit metabolic markers to monitor (and potentially predict) cell proliferation and the osteogenic ability of different donors.
Topics: Humans; Osteogenesis; Phosphorylcholine; Mesenchymal Stem Cells; Cell Differentiation; Adipose Tissue
PubMed: 36497004
DOI: 10.3390/cells11233745 -
Nucleic Acids Research Aug 2023Antisense oligonucleotides (ASOs) are becoming a promising class of drugs for treating various diseases. Over the past few decades, many modified nucleic acids have been...
Antisense oligonucleotides (ASOs) are becoming a promising class of drugs for treating various diseases. Over the past few decades, many modified nucleic acids have been developed for application to ASOs, aiming to enhance their duplex-forming ability toward cognate mRNA and improve their stability against enzymatic degradations. Modulating the sugar conformation of nucleic acids by substituting an electron-withdrawing group at the 2'-position or incorporating a 2',4'-bridging structure is a common approach for enhancing duplex-forming ability. Here, we report on incorporating an N-tert-butylguanidinium group at the 2',4'-bridging structure, which greatly enhances duplex-forming ability because of its interactions with the minor groove. Our results indicated that hydrophobic substituents fitting the grooves of duplexes also have great potential to increase duplex-forming ability.
Topics: Methylguanidine; Nucleic Acid Conformation; Oligonucleotides; Oligonucleotides, Antisense; RNA, Messenger; Guanidines
PubMed: 37462081
DOI: 10.1093/nar/gkad608 -
Biomedicine & Pharmacotherapy =... Nov 2021Hepatitis C virus (HCV) infection induces a long-term inflammatory response and oxidative-stress in the liver microenvironment, leading to hepatic fibrosis and metabolic...
Hepatitis C virus (HCV) infection induces a long-term inflammatory response and oxidative-stress in the liver microenvironment, leading to hepatic fibrosis and metabolic alterations. Direct-acting-antiviral-agents (DAAs) induce HCV-clearance, even though liver damage is only partially restored. In this context, understanding the impact of viral-eradication on liver metabolic activities could allow optimizing the metabolic care of the patient. The present prospective longitudinal study aims at characterizing the urinary metabolic profile of HCV-induced severe liver fibrosis and the metabolic changes induced by DAAs and HCV-clearance by nuclear magnetic resonance-based metabolomics. The urinary metabolic profile of 23 HCV males with severe liver fibrosis and 20 age-matched healthy-controls was analyzed by NMR-based-metabolomics before starting DAAs, at the end-of-therapy, after one and three months of follow-up. The urinary metabolic profile of patients with severe liver fibrosis was associated to pseudouridine, hypoxanthine, methylguanidine and dimethylamine, highlighting a profile related to oxidative damage, and to tyrosine and glutamine, related to a decreased breakdown of aromatic aminoacids and ammonia detoxification, respectively. 1-methylnicotinamide, a catabolic intermediate of nicotinamide-adenine-dinucleotide, was significantly increased in HCV-patients and restored after HCV-clearance, probably due to the reduced hepatic inflammation. 3-hydroxy-3-methylbutyrate, an intermediate of leucine-catabolism which was permanently restored after HCV-clearance, suggested an improvement of skeletal muscle protein synthesis. Finally, 3-hydroxyisobutyrate and 2,3-dihydroxy-2-methylbutyrate, intermediates of valine-catabolism, glycine and choline increased temporarily during therapy, resulting as potential biomarkers of DAAs systemic effects.
Topics: Aged; Antiviral Agents; Biomarkers; Hepatitis C; Humans; Hydroxybutyrates; Liver Cirrhosis; Male; Metabolome; Metabolomics; Middle Aged; Niacinamide; Predictive Value of Tests; Proton Magnetic Resonance Spectroscopy; Severity of Illness Index; Sustained Virologic Response; Time Factors; Treatment Outcome; Urinalysis
PubMed: 34560544
DOI: 10.1016/j.biopha.2021.112217