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Anderson GM. Determination of Indolepropionic Acid and Related Indoles in Plasma, Plasma Ultrafiltrate, and Saliva. Metabolites 2023; 13:metabo13050602. [PMID: 37233643 DOI: 10.3390/metabo13050602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 04/19/2023] [Accepted: 04/24/2023] [Indexed: 05/27/2023] Open
Abstract
The microbial metabolite indolepropionic acid (IPA) and related indolic metabolites, including indolecarboxylic acid (ICA), indolelactic acid (ILA), indoleacetic acid (IAA), indolebutyric acid (IBA), indoxylsulfate (ISO4), and indole, were determined in human plasma, plasma ultrafiltrate (UF), and saliva. The compounds were separated on a 150 × 3 mm column of 3 μm Hypersil C18 eluted with a mobile phase of 80% pH 5 0.01 M sodium acetate containing 1.0 g/L of tert-butylammonium chloride/20% acetonitrile and then detected fluorometrically. Levels of IPA in human plasma UF and of ILA in saliva are reported for the first time. The determination of IPA in plasma UF enables the first report of free plasma IPA, the presumed physiologically active pool of this important microbial metabolite of tryptophan. Plasma and salivary ICA and IBA were not detected, consistent with the absence of any prior reported values. Observed levels or limits of detection for other indolic metabolites usefully supplement limited prior reports.
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Affiliation(s)
- George M Anderson
- Department of Laboratory Medicine, The Child Study Center, Yale University School of Medicine, 230 S. Frontage Rd., New Haven, CT 06519, USA
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2
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Dehghan Niestanak V, Unsworth LD. Detailing Protein-Bound Uremic Toxin Interaction Mechanisms with Human Serum Albumin in the Pursuit of Designing Competitive Binders. Int J Mol Sci 2023; 24:ijms24087452. [PMID: 37108613 PMCID: PMC10139063 DOI: 10.3390/ijms24087452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 04/12/2023] [Accepted: 04/15/2023] [Indexed: 04/29/2023] Open
Abstract
Chronic kidney disease is the gradual progression of kidney dysfunction and involves numerous co-morbidities, one of the leading causes of mortality. One of the primary complications of kidney dysfunction is the accumulation of toxins in the bloodstream, particularly protein-bound uremic toxins (PBUTs), which have a high affinity for plasma proteins. The buildup of PBUTs in the blood reduces the effectiveness of conventional treatments, such as hemodialysis. Moreover, PBUTs can bind to blood plasma proteins, such as human serum albumin, alter their conformational structure, block binding sites for other valuable endogenous or exogenous substances, and exacerbate the co-existing medical conditions associated with kidney disease. The inadequacy of hemodialysis in clearing PBUTs underscores the significance of researching the binding mechanisms of these toxins with blood proteins, with a critical analysis of the methods used to obtain this information. Here, we gathered the available data on the binding of indoxyl sulfate, p-cresyl sulfate, indole 3-acetic acid, hippuric acid, 3-carboxyl-4-methyl-5-propyl-2-furan propanoic acid, and phenylacetic acid to human serum albumin and reviewed the common techniques used to investigate the thermodynamics and structure of the PBUT-albumin interaction. These findings can be critical in investigating molecules that can displace toxins on HSA and improve their clearance by standard dialysis or designing adsorbents with greater affinity for PBUTs than HSA.
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Affiliation(s)
- Vida Dehghan Niestanak
- Department of Biomedical Engineering, University of Alberta, Edmonton, AB T6G 2G4, Canada
| | - Larry D Unsworth
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada
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3
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Employing biochemical biomarkers for building decision tree models to predict bipolar disorder from major depressive disorder. J Affect Disord 2022; 308:190-198. [PMID: 35439462 DOI: 10.1016/j.jad.2022.03.080] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 03/08/2022] [Accepted: 03/18/2022] [Indexed: 12/20/2022]
Abstract
BACKGROUND Conventional biochemical parameters may have predictive values for use in clinical identification between bipolar disorder (BD) and major depressive disorder (MDD). METHODS This study enrolled 2470 hospitalized patients with BD (n = 1333) or MDD (n = 1137) at reproductive age from 2009 to 2018 in China. We extracted 8 parameters, uric acid (UA), direct bilirubin (DBIL), indirect bilirubin (IDBIL), lactic dehydrogenase (LDH), free triiodothyronine (FT3), thyroid-stimulating hormone (TSH), high-density lipoprotein (HDL) and prealbumin of male, patients and 12 parameters, UA, DBIL, IBIL, LDH, FT3, TSH, glutamic-pyruvic transaminase (GPT), white blood cell (WBC), alkaline phosphatase (ALP), fasting blood glucose (FBG), triglyceride and low-density lipoprotein (LDL) of female patients. Backward stepwise multivariate regression analysis and the Chi-Square Automatic Interaction Detection (CHAID) segmentation analysis via SPSS Decision Tree were implemented to define the discrimination of BD and MDD. RESULTS DBIL was extracted as the first splitting variable, with LDH and IBIL as the second, TSH and prealbumin as the third in the model of male patients (p-value < .05). For the model of female patients, DBIL was also extracted as the first splitting variable, with UA, LDH, and IBIL as the second, triglyceride and FT3 as the third (p-value < .05). The predictive accuracies of the Decision Tree and multiple logistic regression models were similar (74.9% vs 76.9% in males; 74.4% vs 79.5% in females). CONCLUSIONS This study suggests the value of the Decision Tree models, which employ biochemical parameters as diagnostic predictors for BD and MDD. The CHAID Decision Tree identified that patients with concomitantly increased LDH, IBIL, and decreased DBIL could be in the group that showed the highest risk of being diagnosed as BD.
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Mo Y, Jie X, Wang L, Ji C, Gu Y, Lu Z, Liu X. Bupi Yishen formula attenuates kidney injury in 5/6 nephrectomized rats via the tryptophan-kynurenic acid-aryl hydrocarbon receptor pathway. BMC Complement Med Ther 2021; 21:207. [PMID: 34376166 PMCID: PMC8353787 DOI: 10.1186/s12906-021-03376-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Accepted: 07/06/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Bupi Yishen Formula (BYF), a patent traditional Chinese medicine (TCM) formulation, has been used in the clinical treatment of chronic kidney disease (CKD). However, the mechanism of action of BYF has not been fully elucidated. METHOD To investigate the variation in the metabolic profile in response to BYF treatment in a rat model of 5/6 nephrectomy (Nx), rats in the treatment groups received low- or high-dose BYF. At the end of the study, serum and kidney samples were collected for biochemical, pathological, and western blotting analysis. Metabolic changes in serum were analyzed by liquid chromatography-tandem mass spectrometry. RESULTS The results showed that BYF treatment could reduce kidney injury, inhibit inflammation and improve renal function in a dose-dependent manner. In total, 405 and 195 metabolites were identified in negative and positive ion modes, respectively. Metabolic pathway enrichment analysis of differential metabolites based on the Kyoto Encyclopedia of Genes and Genomes database identified 35 metabolic pathways, 3 of which were related to tryptophan metabolism. High-dose BYF reduced the level of kynurenic acid (KA) by more than 50%, while increasing melatonin 25-fold and indole-3-acetic acid twofold. Expression levels of aryl hydrocarbon receptor (AhR), Cyp1A1, and CyP1B1 were significantly reduced in the kidney tissue of rats with high-dose BYF, compared to 5/6 Nx rats. CONCLUSION BYF has a reno-protective effect against 5/6 Nx-induced CKD, which may be mediated via inhibition of the tryptophan-KA-AhR pathway.
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Affiliation(s)
- Yenan Mo
- The Second Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, 520120, China
| | - Xina Jie
- The Second Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, 520120, China
| | - Lixin Wang
- Nephrology Department, the Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, 520120, China
| | - Chunlan Ji
- The Second Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, 520120, China
| | - Yueyu Gu
- Nephrology Department, the Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, 520120, China
| | - Zhaoyu Lu
- The Second Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, 520120, China. .,Nephrology Department, the Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, 520120, China.
| | - Xusheng Liu
- Nephrology Department, the Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, 520120, China.
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Protein-Bound Uremic Toxins in Hemodialysis Patients Relate to Residual Kidney Function, Are Not Influenced by Convective Transport, and Do Not Relate to Outcome. Toxins (Basel) 2020; 12:toxins12040234. [PMID: 32272776 PMCID: PMC7232478 DOI: 10.3390/toxins12040234] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 03/31/2020] [Accepted: 04/05/2020] [Indexed: 01/13/2023] Open
Abstract
Protein-bound uremic toxins (PBUTs) are predominantly excreted by renal tubular secretion and hardly removed by traditional hemodialysis (HD). Accumulation of PBUTs is proposed to contribute to the increased morbidity and mortality of patients with end-stage kidney disease (ESKD). Preserved PBUT excretion in patients with residual kidney function (RKF) and/or increased PBUT clearance with improved dialysis techniques might improve the prognosis of patients with ESKD. The aims of this study are to explore determinants of PBUTs in HD patients, and investigate whether hemodiafiltration (HDF) lowers PBUT plasma concentrations, and whether PBUTs are related to the outcome. Predialysis total plasma concentrations of kynurenine, kynurenic acid, indoxyl sulfate, indole-3-acetic acid, p-cresyl sulfate, p-cresyl glucuronide, and hippuric acid were measured by UHPLC-MS at baseline and after 6 months of follow-up in the first 80 patients participating in the CONvective TRAnsport Study (CONTRAST), a randomized controlled trial that compared the effects of online HDF versus low-flux HD on all-cause mortality and new cardiovascular events. RKF was inversely related to kynurenic acid (p < 0.001), indoxyl sulfate (p = 0.001), indole-3-acetic acid (p = 0.024), p-cresyl glucuronide (p = 0.004) and hippuric acid (p < 0.001) plasma concentrations. Only indoxyl sulfate decreased by 8.0% (−15.3 to 34.6) in patients treated with HDF and increased by 11.9% (−15.4 to 31.9) in HD patients after 6 months of follow-up (HDF vs. HD: p = 0.045). No independent associations were found between PBUT plasma concentrations and either risk of all-cause mortality or new cardiovascular events. In summary, in the current population, RKF is an important determinant of PBUT plasma concentrations in HD patients. The addition of convective transport did not consistently decrease PBUT plasma concentrations and no relation was found between PBUTs and cardiovascular endpoints.
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6
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Atherton JG, Hains DS, Bissler J, Pendley BD, Lindner E. Generation, clearance, toxicity, and monitoring possibilities of unaccounted uremic toxins for improved dialysis prescriptions. Am J Physiol Renal Physiol 2018. [PMID: 29537310 DOI: 10.1152/ajprenal.00106.2017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Current dialysis-dosing calculations provide an incomplete assessment of blood purification. They exclude clearances of protein-bound uremic toxins (PB-UTs), such as polyamines, p-cresol sulfate, and indoxyl sulfate, relying solely on the clearance of urea as a surrogate for all molecules accumulating in patients with end-stage renal disease (ESRD). PB-UTs clear differently in dialysis but also during normal renal function. The kidney clears PB toxins via the process of secretion, whereas it clears urea through filtration. Herein, we review the clearance, accumulation, and toxicity of various UTs. We also suggest possible methods for their monitoring toward the ultimate goal of a more comprehensive dialysis prescription. A more inclusive dialysis prescription would retain the kidney-filtration surrogate, urea, and consider at least one PB toxin as a surrogate for UTs cleared through cellular secretion. A more comprehensive assessment of UTs that includes both secretion and filtration is expected to result in a better understanding of ESRD toxicity and consequently, to reduce ESRD mortality.
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Affiliation(s)
- James G Atherton
- Department of Biomedical Engineering, University of Memphis , Memphis, Tennessee.,Le Bonheur Children's Hospital , Memphis, Tennessee
| | | | - John Bissler
- Le Bonheur Children's Hospital , Memphis, Tennessee
| | - Bradford D Pendley
- Department of Biomedical Engineering, University of Memphis , Memphis, Tennessee
| | - Ernő Lindner
- Department of Biomedical Engineering, University of Memphis , Memphis, Tennessee
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7
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Ellis RJ, Small DM, Ng KL, Vesey DA, Vitetta L, Francis RS, Gobe GC, Morais C. Indoxyl Sulfate Induces Apoptosis and Hypertrophy in Human Kidney Proximal Tubular Cells. Toxicol Pathol 2018; 46:449-459. [PMID: 29683083 DOI: 10.1177/0192623318768171] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Indoxyl sulfate (IS) is a protein-bound uremic toxin that accumulates in patients with declining kidney function. Although generally thought of as a consequence of declining kidney function, emerging evidence demonstrates direct cytotoxic role of IS on endothelial cells and cardiomyocytes, largely through the expression of pro-inflammatory and pro-fibrotic factors. The direct toxicity of IS on human kidney proximal tubular epithelial cells (PTECs) remains a matter of debate. The current study explored the effect of IS on primary cultures of human PTECs and HK-2, an immortalized human PTEC line. Pathologically relevant concentrations of IS induced apoptosis and increased the expression of the proapoptotic molecule Bax in both cell types. IS impaired mitochondrial metabolic activity and induced cellular hypertrophy. Furthermore, statistically significant upregulation of pro-fibrotic (transforming growth factor-β, fibronectin) and pro-inflammatory molecules (interleukin-6, interleukin-8, and tumor necrosis factor-α) in response to IS was observed. Albumin had no influence on the toxicity of IS. The results of this study suggest that IS directly induced a pro-inflammatory and pro-fibrotic phenotype in proximal tubular cells. In light of the associated apoptosis, hypertrophy, and metabolic dysfunction, this study demonstrates that IS may play a role in the progression of chronic kidney disease.
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Affiliation(s)
- Robert J Ellis
- 1 Centre for Kidney Disease Research, Translational Research Institute, University of Queensland, Brisbane, Australia.,2 Department of Urology, Princess Alexandra Hospital, Brisbane, Australia
| | - David M Small
- 1 Centre for Kidney Disease Research, Translational Research Institute, University of Queensland, Brisbane, Australia.,3 Department of Biomedical Engineering, Cornell University, Ithaca, New York, USA
| | - Keng Lim Ng
- 1 Centre for Kidney Disease Research, Translational Research Institute, University of Queensland, Brisbane, Australia.,2 Department of Urology, Princess Alexandra Hospital, Brisbane, Australia
| | - David A Vesey
- 1 Centre for Kidney Disease Research, Translational Research Institute, University of Queensland, Brisbane, Australia.,4 Department of Nephrology, Princess Alexandra Hospital, Brisbane, Australia
| | - Luis Vitetta
- 5 Sydney Medical School, University of Sydney, Sydney, Australia.,6 Medlab Clinical, Sydney, Australia
| | - Ross S Francis
- 1 Centre for Kidney Disease Research, Translational Research Institute, University of Queensland, Brisbane, Australia.,4 Department of Nephrology, Princess Alexandra Hospital, Brisbane, Australia
| | - Glenda C Gobe
- 1 Centre for Kidney Disease Research, Translational Research Institute, University of Queensland, Brisbane, Australia
| | - Christudas Morais
- 1 Centre for Kidney Disease Research, Translational Research Institute, University of Queensland, Brisbane, Australia
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Otterbein LE, Foresti R, Motterlini R. Heme Oxygenase-1 and Carbon Monoxide in the Heart: The Balancing Act Between Danger Signaling and Pro-Survival. Circ Res 2017; 118:1940-1959. [PMID: 27283533 DOI: 10.1161/circresaha.116.306588] [Citation(s) in RCA: 145] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 05/02/2016] [Indexed: 12/22/2022]
Abstract
Understanding the processes governing the ability of the heart to repair and regenerate after injury is crucial for developing translational medical solutions. New avenues of exploration include cardiac cell therapy and cellular reprogramming targeting cell death and regeneration. An attractive possibility is the exploitation of cytoprotective genes that exist solely for self-preservation processes and serve to promote and support cell survival. Although the antioxidant and heat-shock proteins are included in this category, one enzyme that has received a great deal of attention as a master protective sentinel is heme oxygenase-1 (HO-1), the rate-limiting step in the catabolism of heme into the bioactive signaling molecules carbon monoxide, biliverdin, and iron. The remarkable cardioprotective effects ascribed to heme oxygenase-1 are best evidenced by its ability to regulate inflammatory processes, cellular signaling, and mitochondrial function ultimately mitigating myocardial tissue injury and the progression of vascular-proliferative disease. We discuss here new insights into the role of heme oxygenase-1 and heme on cardiovascular health, and importantly, how they might be leveraged to promote heart repair after injury.
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Affiliation(s)
- Leo E Otterbein
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215
| | - Roberta Foresti
- Inserm, U955, Equipe 12, Créteil, 94000, France.,University Paris Est, Faculty of Medicine, Créteil, 94000, France
| | - Roberto Motterlini
- Inserm, U955, Equipe 12, Créteil, 94000, France.,University Paris Est, Faculty of Medicine, Créteil, 94000, France
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9
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Pan L, Ye X, Ding J, Zhou Y. Antiproliferation effect of the uremic toxin para‑cresol on endothelial progenitor cells is related to its antioxidant activity. Mol Med Rep 2017; 15:2308-2312. [PMID: 28260040 PMCID: PMC5364822 DOI: 10.3892/mmr.2017.6230] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 01/10/2017] [Indexed: 01/14/2023] Open
Abstract
Endothelial dysfunction and impaired endothelial regenerative capacity are key contributors to the high incidence of cardiovascular disease in patients with chronic kidney disease (CKD). Uremic toxins are associated with this pathogenesis. Previous studies have revealed that a uremic toxin, para-cresol (p-cresol), exerts an antiproliferation effect on human endothelial progenitor cells (EPCs), but the mechanism remains unclear. In the present study, reactive oxygen species (ROS) were confirmed to function as signaling molecules that regulate growth factor-dependent EPC proliferation. EPCs were treated with p-cresol for 72 h, using a concentration range typically found in CKD patients. ROS production was analyzed by fluorescence microscopy and flow cytometry, and protein expression levels of nicotinamide adenine dinucleotide phosphate oxidase, a major source of ROS, were analyzed by western blot analysis. mRNA expression levels of antioxidant genes were assessed by reverse transcription-quantitative polymerase chain reaction analysis. The results revealed that p-cresol partially inhibits ROS production, and this effect may be associated with a significant reduction in cytochrome b-245 alpha and beta chain expression in EPCs. An increase of glutathione peroxidase 4 mRNA expression was also detected. In conclusion, the present study revealed that the antiproliferation effect of p-cresol on EPCs might act via its antioxidant activity. The results of the present study may facilitate understanding of uremic toxin toxicity on the cardiovascular system.
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Affiliation(s)
- Limin Pan
- Department of Anesthesiology, The Third Affiliated Hospital to Wenzhou Medical College, Rui'an, Zhejiang 325200, P.R. China
| | - Xiaoting Ye
- Department of Anesthesiology, The Third Affiliated Hospital to Wenzhou Medical College, Rui'an, Zhejiang 325200, P.R. China
| | - Jiguang Ding
- Department of Infectious Diseases, The Third Affiliated Hospital to Wenzhou Medical College, Rui'an, Zhejiang 325200, P.R. China
| | - Yu Zhou
- Department of Infectious Diseases, The Third Affiliated Hospital to Wenzhou Medical College, Rui'an, Zhejiang 325200, P.R. China
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Individual variability in human blood metabolites identifies age-related differences. Proc Natl Acad Sci U S A 2016; 113:4252-9. [PMID: 27036001 DOI: 10.1073/pnas.1603023113] [Citation(s) in RCA: 249] [Impact Index Per Article: 31.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Metabolites present in human blood document individual physiological states influenced by genetic, epigenetic, and lifestyle factors. Using high-resolution liquid chromatography-mass spectrometry (LC-MS), we performed nontargeted, quantitative metabolomics analysis in blood of 15 young (29 ± 4 y of age) and 15 elderly (81 ± 7 y of age) individuals. Coefficients of variation (CV = SD/mean) were obtained for 126 blood metabolites of all 30 donors. Fifty-five RBC-enriched metabolites, for which metabolomics studies have been scarce, are highlighted here. We found 14 blood compounds that show remarkable age-related increases or decreases; they include 1,5-anhydroglucitol, dimethyl-guanosine, acetyl-carnosine, carnosine, ophthalmic acid, UDP-acetyl-glucosamine,N-acetyl-arginine,N6-acetyl-lysine, pantothenate, citrulline, leucine, isoleucine, NAD(+), and NADP(+) Six of them are RBC-enriched, suggesting that RBC metabolomics is highly valuable for human aging research. Age differences are partly explained by a decrease in antioxidant production or increasing inefficiency of urea metabolism among the elderly. Pearson's coefficients demonstrated that some age-related compounds are correlated, suggesting that aging affects them concomitantly. Although our CV values are mostly consistent with those CVs previously published, we here report previously unidentified CVs of 51 blood compounds. Compounds having moderate to high CV values (0.4-2.5) are often modified. Compounds having low CV values, such as ATP and glutathione, may be related to various diseases because their concentrations are strictly controlled, and changes in them would compromise health. Thus, human blood is a rich source of information about individual metabolic differences.
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Assis RP, Castro JFA, Gutierres VO, Arcaro CA, Brotto RS, Oliveira OMMF, Baviera AM, Brunetti IL. Effects of uremic solutes on reactive oxygen species in vitro model systems as a possibility of support the renal function management. BMC Nephrol 2015; 16:50. [PMID: 25886160 PMCID: PMC4399422 DOI: 10.1186/s12882-015-0029-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 03/06/2015] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND In view of the prevalence of oxidative stress in chronic kidney disease (CKD) patients, the loss of low-molecular-weight biomolecules by hemodialysis and the antioxidant potential of some uremic solutes that accumulate in CKD, we used in vitro model systems to test the antioxidant potential of the following uremic solutes: uric acid, hippuric acid, p-cresol, phenol, methylguanidine, L-arginine, L-tyrosine, creatinine and urea. METHODS The in vitro antioxidant efficiencies of the uremic solutes, isolated or in mixtures, were tested with the following assays: i) ABTS radical cation decolorization assay; ii) hypochlorous acid (HOCl/OCl(-)) scavenging activity; iii) superoxide anion radical (O2(•-)) scavenging activity; iv) crocin bleaching assay (capture of peroxyl radical, ROO(•)); v) hydrogen peroxide (H2O2) scavenging activity. RESULTS Four of the tested uremic solutes (p-cresol, phenol, L-tyrosine, uric acid) were effective antioxidants and their IC50 were found in three model systems: ABTS(•+), HOCl/OCl(-) and crocin bleaching assay. In the 4-solutes mixtures, each one of the solute captured 12.5% for the IC50 of the mixture to ABTS(•+) or HOCl/OCl(-), exhibiting a virtually exact additive effect. In the 2-solutes mixtures, for ROO(•) capture, it was observed the need of more mass of uremic solutes to reach an IC50 value that was higher than the projected IC50, obtained from the IC50 of single solutes (25% of each, in the binary mixtures) in the same assay. In model systems for O2(•-) and H2O2, none of the uremic solutes showed scavenging activity. CONCLUSIONS The use of the IC50 as an analytical tool to prepare and analyze mixtures allows the determination of their scavenging capacities and may be useful for the assessment of the antioxidant status of biological samples under conditions of altered levels of the endogenous antioxidant network and/or in the employment and monitoring of exogenous antioxidant therapy.
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Affiliation(s)
- Renata P Assis
- Department of Clinical Analysis, School of Pharmaceutical Sciences, São Paulo State University - UNESP, Rua Expedicionários do Brasil 1621, Araraquara, CEP 14801-902, São Paulo, Brazil.
| | - Juliana F A Castro
- Department of Biochemistry and Technological Chemistry, Institute of Chemistry, São Paulo State University - UNESP, Rua Prof. Francisco Degni 55, Araraquara, CEP 14800-900, São Paulo, Brazil.
| | - Vânia O Gutierres
- Department of Clinical Analysis, School of Pharmaceutical Sciences, São Paulo State University - UNESP, Rua Expedicionários do Brasil 1621, Araraquara, CEP 14801-902, São Paulo, Brazil.
| | - Carlos A Arcaro
- Department of Clinical Analysis, School of Pharmaceutical Sciences, São Paulo State University - UNESP, Rua Expedicionários do Brasil 1621, Araraquara, CEP 14801-902, São Paulo, Brazil.
| | - Renata S Brotto
- Department of Clinical Analysis, School of Pharmaceutical Sciences, São Paulo State University - UNESP, Rua Expedicionários do Brasil 1621, Araraquara, CEP 14801-902, São Paulo, Brazil.
| | - Olga M M F Oliveira
- Department of Biochemistry and Technological Chemistry, Institute of Chemistry, São Paulo State University - UNESP, Rua Prof. Francisco Degni 55, Araraquara, CEP 14800-900, São Paulo, Brazil.
| | - Amanda M Baviera
- Department of Clinical Analysis, School of Pharmaceutical Sciences, São Paulo State University - UNESP, Rua Expedicionários do Brasil 1621, Araraquara, CEP 14801-902, São Paulo, Brazil.
| | - Iguatemy L Brunetti
- Department of Clinical Analysis, School of Pharmaceutical Sciences, São Paulo State University - UNESP, Rua Expedicionários do Brasil 1621, Araraquara, CEP 14801-902, São Paulo, Brazil.
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Corredor Z, Stoyanova E, Rodríguez-Ribera L, Coll E, Silva I, Diaz JM, Ballarin J, Marcos R, Pastor S. Genomic damage as a biomarker of chronic kidney disease status. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2015; 56:301-312. [PMID: 25234591 DOI: 10.1002/em.21911] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 09/03/2014] [Accepted: 09/04/2014] [Indexed: 06/03/2023]
Abstract
Patients suffering from chronic kidney disease (CKD) exhibit a high incidence of cancer and cardiovascular diseases, as well as high levels of genomic damage. To confirm the association of CKD with genomic damage we have carried out the largest study to date addressing this issue, using a total of 602 subjects (187 controls, 206 pre-dialysis CKD patients and 209 CKD patients in hemodialysis). DNA oxidative damage was measured in all individuals using the comet assay. Our results indicate that CKD patients have significantly higher levels of DNA damage than controls, but no significant differences were observed between pre-hemodialysis (pre-HD) and hemodialysis (HD) patients. When oxidative damage was measured, no differences were observed between patients and controls, although HD patients showed significantly higher levels of oxidative damage than pre-HD patients. In addition, a positive relationship was demonstrated between genomic damage and all-cause mortality. Our study confirms that genomic damage can be predictive of prognosis in CKD patients, with high levels of DNA damage indicating a poor prognosis in HD patients.
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Affiliation(s)
- Zuray Corredor
- Grup de Mutagènesi, Departament de Genètica i de Microbiologia, Edifici C, Universitat Autònoma de Barcelona, 08193, Bellaterra, Cerdanyola del Vallès, Spain
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13
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Teng J, Tian J, Lv WL, Zhang XY, Zou JZ, Fang Y, Yu J, Shen B, Liu ZH, Ding XQ. Inappropriately elevated endothelin-1 plays a role in the pathogenesis of intradialytic hypertension. Hemodial Int 2014; 19:279-86. [PMID: 25345870 DOI: 10.1111/hdi.12238] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 09/19/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Jie Teng
- Department of Nephrology; Zhongshan Hospital; Shanghai Medical College; Fudan University; No 180 Fenglin Road Shanghai 200032 China
- Kidney and Dialysis Institute of Shanghai; No 180 Fenglin Road Shanghai 200032 China
- Kidney and Blood Purification Laboratory of Shanghai; No 180 Fenglin Road Shanghai 200032 China
| | - Jie Tian
- Department of Nephrology; Zhongshan Hospital; Shanghai Medical College; Fudan University; No 180 Fenglin Road Shanghai 200032 China
- Department of Blood Purification; Fujian Provincial Hospital; No 134 Dong Street Fuzhou 350001 China
| | - Wen-Lv Lv
- Department of Nephrology; Zhongshan Hospital; Shanghai Medical College; Fudan University; No 180 Fenglin Road Shanghai 200032 China
- Kidney and Dialysis Institute of Shanghai; No 180 Fenglin Road Shanghai 200032 China
| | - Xiao-Yan Zhang
- Department of Nephrology; Zhongshan Hospital; Shanghai Medical College; Fudan University; No 180 Fenglin Road Shanghai 200032 China
- Kidney and Dialysis Institute of Shanghai; No 180 Fenglin Road Shanghai 200032 China
| | - Jian-Zhou Zou
- Department of Nephrology; Zhongshan Hospital; Shanghai Medical College; Fudan University; No 180 Fenglin Road Shanghai 200032 China
- Kidney and Dialysis Institute of Shanghai; No 180 Fenglin Road Shanghai 200032 China
| | - Yi Fang
- Department of Nephrology; Zhongshan Hospital; Shanghai Medical College; Fudan University; No 180 Fenglin Road Shanghai 200032 China
- Kidney and Dialysis Institute of Shanghai; No 180 Fenglin Road Shanghai 200032 China
- Kidney and Blood Purification Laboratory of Shanghai; No 180 Fenglin Road Shanghai 200032 China
| | - Jinbo Yu
- Department of Nephrology; Zhongshan Hospital; Shanghai Medical College; Fudan University; No 180 Fenglin Road Shanghai 200032 China
- Kidney and Dialysis Institute of Shanghai; No 180 Fenglin Road Shanghai 200032 China
| | - Bo Shen
- Department of Nephrology; Zhongshan Hospital; Shanghai Medical College; Fudan University; No 180 Fenglin Road Shanghai 200032 China
- Kidney and Dialysis Institute of Shanghai; No 180 Fenglin Road Shanghai 200032 China
| | - Zhong-Hua Liu
- Department of Nephrology; Zhongshan Hospital; Shanghai Medical College; Fudan University; No 180 Fenglin Road Shanghai 200032 China
- Kidney and Dialysis Institute of Shanghai; No 180 Fenglin Road Shanghai 200032 China
| | - Xiao-Qiang Ding
- Department of Nephrology; Zhongshan Hospital; Shanghai Medical College; Fudan University; No 180 Fenglin Road Shanghai 200032 China
- Kidney and Dialysis Institute of Shanghai; No 180 Fenglin Road Shanghai 200032 China
- Kidney and Blood Purification Laboratory of Shanghai; No 180 Fenglin Road Shanghai 200032 China
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Schulz AM, Terne C, Jankowski V, Cohen G, Schaefer M, Boehringer F, Tepel M, Kunkel D, Zidek W, Jankowski J. Modulation of NADPH oxidase activity by known uraemic retention solutes. Eur J Clin Invest 2014; 44:802-11. [PMID: 25041433 DOI: 10.1111/eci.12297] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2013] [Accepted: 06/24/2014] [Indexed: 12/18/2022]
Abstract
BACKGROUND Uraemia and cardiovascular disease appear to be associated with an increased oxidative burden. One of the key players in the genesis of reactive oxygen species (ROS) is nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. Based on initial experiments demonstrating a decreased inhibitory effect on NADPH oxidase activity in the presence of plasma from patients with CKD-5D after dialysis compared with before dialysis, we investigated the effect of 48 known and commercially available uraemic retention solutes on the enzymatic activity of NADPH oxidase. METHODS Mononuclear leucocytes isolated from buffy coats of healthy volunteers were isolated, lysed and incubated with NADH in the presence of plasma from healthy controls and patients with CKD-5D. Furthermore, the leucocytes were lysed and incubated in the presence of uraemic retention solute of interest and diphenyleneiodonium chloride (DPI), an inhibitor of NADPH oxidase. The effect on enzymatic activity of NADPH oxidase was quantified within an incubation time of 120 min. RESULTS Thirty-nine of the 48 uraemic retention solutes tested had a significant decreasing effect on NADPH oxidase activity. Oxalate has been characterized as the strongest inhibitor of NADPH oxidase (90% of DPI inhibition). Surprisingly, none of the uraemic retention solutes we investigated was found to increase NADPH oxidase activity. Furthermore, plasma from patients with CKD-5D before dialysis caused significantly higher inhibitory effect on NADPH oxidase activity compared with plasma from healthy subjects. However, this effect was significantly decreased in plasma from patients with CKD-5D after dialysis. CONCLUSIONS The results of this study show that uraemic retention solutes modulated the activity of the NADPH oxidase. The results of this study might be the basis for the development of inhibitors applicable as drug in the situation of increased oxidative stress.
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Affiliation(s)
- Anna Marta Schulz
- Charité-Universitätsmedizin Berlin (CBF), Medizinische Klinik IV, Berlin, Germany
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15
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Praschberger M, Hermann M, Wanner J, Jirovetz L, Exner M, Kapiotis S, Gmeiner BMK, Laggner H. The uremic toxin indoxyl sulfate acts as a pro- or antioxidant on LDL oxidation. Free Radic Res 2014; 48:641-8. [PMID: 24568219 DOI: 10.3109/10715762.2014.898294] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Uremic toxins have been shown to play a role in chronic kidney disease (CKD) associated oxidative stress. Oxidative stress and inflammation have been associated with increased risk of cardiovascular disease in uraemia. The oxidative modification of LDL may play a role in early atherogenesis. Enhanced LDL oxidation has been found in uremic patients which may account for accelerated atherosclerosis observed in CKD. The uremic toxin indoxyl sulfate (IS) has been reported to exert oxidative and antioxidative activity. Thus, in the present study we have investigated the influence of IS on the atherogenic modifications of LDL exposed in vitro to different oxidising systems. The transition metal ion (Cu(2+)) and hemin/H2O2 induced lipid oxidation reactions monitored by conjugated diene formation, were inhibited by the presence of IS, which points to possible antioxidant effects by this uremic toxin. A protective effect of IS on LDL apoprotein modification by the exposure to the product of the myeloperoxidase/H2O2/Cl(-) system HOCl, was also observed as estimated by protein carbonyl formation. In contrast, a marked increase in conjugated dienes and lipid hydroperoxides was observed when lipid oxidation was initiated by the free radical generator AAPH in presence of IS. The GC-MS analysis revealed the formation of indole-2,3-dione and 6,12-dihydro-6,12-dioxo-indolo[2,1-b]quinazoline (tryptanthrin) in IS/AAPH reaction. A scheme for the generation of tryptanthrin from IS via indoxyl radicals is proposed, which may facilitate LDL lipid oxidation. Our observations add further insight in the Janus-faced properties of this important uremic toxin.
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Affiliation(s)
- M Praschberger
- Department of Medical Chemistry and Pathobiochemistry, Center of Pathobiochemistry and Genetics, Medical University of Vienna , Vienna , Austria
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16
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Duranton F, Cohen G, De Smet R, Rodriguez M, Jankowski J, Vanholder R, Argiles A. Normal and pathologic concentrations of uremic toxins. J Am Soc Nephrol 2012; 23:1258-70. [PMID: 22626821 DOI: 10.1681/asn.2011121175] [Citation(s) in RCA: 700] [Impact Index Per Article: 58.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
An updated review of the existing knowledge regarding uremic toxins facilitates the design of experimental studies. We performed a literature search and found 621 articles about uremic toxicity published after a 2003 review of this topic. Eighty-seven records provided serum or blood measurements of one or more solutes in patients with CKD. These records described 32 previously known uremic toxins and 56 newly reported solutes. The articles most frequently reported concentrations of β2-microglobulin, indoxyl sulfate, homocysteine, uric acid, and parathyroid hormone. We found most solutes (59%) in only one report. Compared with previous results, more recent articles reported higher uremic concentrations of many solutes, including carboxymethyllysine, cystatin C, and parathyroid hormone. However, five solutes had uremic concentrations less than 10% of the originally reported values. Furthermore, the uremic concentrations of four solutes did not exceed their respective normal concentrations, although they had been previously described as uremic retention solutes. In summary, this review extends the classification of uremic retention solutes and their normal and uremic concentrations, and it should aid the design of experiments to study the biologic effects of these solutes in CKD.
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Abstract
Abstract
The mechanisms of oxidation of low-density lipoproteins (LDLs) are not well defined, but epidemiological and experimental studies suggest that iron-catalyzed processes may contribute to atherogenesis. The aim of this study was to test the hypothesis that iron-catalyzed oxidations of LDLs in vitro produce diagnostic biomarkers of oxidation of the apolipoprotein that could be applied to studies in vivo. LDLs were oxidized in the presence of Fe2+, EDTA, and ascorbic acid for up to 40 h. Following delipidation and trypsin digestion, the peptides were separated by HPLC, with four peaks detected at 365 nm, whereas none were observed in peptides from unoxidized LDLs. The peptides were identified by MALDI-QTOF mass spectrometry as IVQILP(W+4) EQNEQVK, IYSL(W+4)EHSTK, FEGLQE(W+4)EGK, and YH(W+4)EHTGLTLR, with (W+4) rather than the W residues of the unoxidized protein. The mass gains (+4 increase in m/z in tryptophan, W) and absorbance at 365 nm indicate kynurenines, which were trypsin-releasable peptides that are on the surface of LDL particles. All four peptides thus characterized share the sequence of WE. The preferential oxidation of W residues in WE sequences suggest contributions from the C-proximate glutamate residues in chelation of the iron species, thereby influencing site selectivities of oxidation. These kynurenine-containing peptides might serve as biomarkers of iron-mediated oxidations in vivo.
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Balla J, Vercellotti GM, Jeney V, Yachie A, Varga Z, Jacob HS, Eaton JW, Balla G. Heme, heme oxygenase, and ferritin: how the vascular endothelium survives (and dies) in an iron-rich environment. Antioxid Redox Signal 2007; 9:2119-37. [PMID: 17767398 DOI: 10.1089/ars.2007.1787] [Citation(s) in RCA: 148] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Iron-derived reactive oxygen species are involved in the pathogenesis of numerous vascular disorders. One abundant source of redox active iron is heme, which is inherently dangerous when it escapes from its physiologic sites. Here, we present a review of the nature of heme-mediated cytotoxicity and of the strategies by which endothelium manages to protect itself from this clear and present danger. Of all sites in the body, the endothelium may be at greatest risk of exposure to heme. Heme greatly potentiates endothelial cell killing mediated by leukocytes and other sources of reactive oxygen. Heme also promotes the conversion of low-density lipoprotein to cytotoxic oxidized products. Hemoglobin in plasma, when oxidized, transfers heme to endothelium and lipoprotein, thereby enhancing susceptibility to oxidant-mediated injury. As a defense against such stress, endothelial cells upregulate heme oxygenase-1 and ferritin. Heme oxygenase opens the porphyrin ring, producing biliverdin, carbon monoxide, and a most dangerous product-redox active iron. The latter can be effectively controlled by ferritin via sequestration and ferroxidase activity. These homeostatic adjustments have been shown to be effective in the protection of endothelium against the damaging effects of heme and oxidants; lack of adaptation in an iron-rich environment led to extensive endothelial damage in humans.
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Affiliation(s)
- József Balla
- Department of Medicine, University of Debrecen, Debrecen, Hungary.
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19
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Tsirpanlis G, Chatzipanagiotou S, Boufidou F, Kordinas V, Zoga M, Alevyzaki F, Stamatelou K, Frangou E, Savva L, Nicolaou C. Serum oxidized low-density lipoprotein is inversely correlated to telomerase activity in peripheral blood mononuclear cells of haemodialysis patients. Nephrology (Carlton) 2006; 11:506-9. [PMID: 17199788 DOI: 10.1111/j.1440-1797.2006.00697.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Telomerase preserves telomeres' function and structure preventing cellular senescence. Its activity is reduced in peripheral blood mononuclear cells (PBMC) of haemodialysis (HD) patients. The purpose of this study is to investigate the potential correlation between increased oxidative stress/inflammation and telomerase activity in PBMC of HD patients. METHODS Telomerase activity was measured by PCR-ELISA in PBMC isolated from a group of 42 HD patients and 39 subjects with estimated glomerular filtration rate >or=80 mL/min (control group). Serum oxidized low-density lipoprotein (ox-LDL), tumour necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) were also measured in both groups by ELISA. RESULTS Ox-LDL was negatively correlated to percentage telomerase activity in PBMC (r = -0.506, P = 0.000 in the whole group of 81 HD and normal subjects and r = -0.559, P < 0.001 in HD patients). TNF was also inversely associated with percentage telomerase activity in the whole group studied (r = -0.492, P = 0.000) while IL-10 was not. In stepwise multiple linear regression, taking into consideration the most important characteristics of the HD patients and control group, the only significant predictors for percentage telomerase activity in PBMC were ox-LDL and TNF (beta = -0.421, t = -4.083, P = 0.000 and beta = -0.381, t = -3.691, P = 0.000, respectively) while examining separately HD patients, the predictors for the same parameter were ox-LDL and HD duration (beta = -0.671, t = -4.709, P = 0.000 and beta = -0.349, t = -2.447, P = 0.023, respectively). CONCLUSION Ox-LDL serum level is inversely correlated to telomerase activity in PBMC of HD patients. Our study proposes a new consequence of increased oxidative stress in HD patients: the premature cellular senescence potentially related to atherosclerosis through LDL oxidation.
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Meijers BKI, de Loor H, Verbeke K, Evenepoel P. p-Cresol for better or worse: But what are we measuring? Kidney Int 2006; 70:232; author reply 232-3. [PMID: 16810293 DOI: 10.1038/sj.ki.5001530] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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