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Deng LE, Guo M, Deng Y, Pan Y, Wang X, Maduraiveeran G, Liu J, Lu C. MOF-Based Platform for Kidney Diseases: Advances, Challenges, and Prospects. Pharmaceutics 2024; 16:793. [PMID: 38931914 PMCID: PMC11207304 DOI: 10.3390/pharmaceutics16060793] [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: 04/30/2024] [Revised: 06/03/2024] [Accepted: 06/04/2024] [Indexed: 06/28/2024] Open
Abstract
Kidney diseases are important diseases that affect human health worldwide. According to the 2020 World Health Organization (WHO) report, kidney diseases have become the top 10 causes of death. Strengthening the prevention, primary diagnosis, and action of kidney-related diseases is of great significance in maintaining human health and improving the quality of life. It is increasingly challenging to address clinical needs with the present technologies for diagnosing and treating renal illness. Fortunately, metal-organic frameworks (MOFs) have shown great promise in the diagnosis and treatment of kidney diseases. This review summarizes the research progress of MOFs in the diagnosis and treatment of renal disease in recent years. Firstly, we introduce the basic structure and properties of MOFs. Secondly, we focus on the utilization of MOFs in the diagnosis and treatment of kidney diseases. In the diagnosis of kidney disease, MOFs are usually designed as biosensors to detect biomarkers related to kidney disease. In the treatment of kidney disease, MOFs can not only be used as an effective adsorbent for uremic toxins during hemodialysis but also as a precise treatment of intelligent drug delivery carriers. They can also be combined with nano-chelation technology to solve the problem of the imbalance of trace elements in kidney disease. Finally, we describe the current challenges and prospects of MOFs in the diagnosis and treatment of kidney diseases.
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Affiliation(s)
- Li-Er Deng
- Department of Nephrology, Dongguan Traditional Chinese Medicine Hospital, Dongguan 523000, China
| | - Manli Guo
- Dongguan Key Laboratory of Drug Design and Formulation Technology, Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, Guangdong Medical University, Dongguan 523808, China
| | - Yijun Deng
- Dongguan Key Laboratory of Drug Design and Formulation Technology, Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, Guangdong Medical University, Dongguan 523808, China
| | - Ying Pan
- Dongguan Key Laboratory of Drug Design and Formulation Technology, Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, Guangdong Medical University, Dongguan 523808, China
| | - Xiaoxiong Wang
- School of Materials and Environmental Engineering, Shenzhen Polytechnic University, Shenzhen 518055, China
| | - Govindhan Maduraiveeran
- Materials Electrochemistry Laboratory, Department of Chemistry, SRM Institute of Science and Technology, Kattankulathur 603 203, Tamil Nadu, India;
| | - Jianqiang Liu
- Dongguan Key Laboratory of Drug Design and Formulation Technology, Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, Guangdong Medical University, Dongguan 523808, China
| | - Chengyu Lu
- Dongguan Key Laboratory of Drug Design and Formulation Technology, Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, Guangdong Medical University, Dongguan 523808, China
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2
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Meijers B, Zadora W, Lowenstein J. A Historical Perspective on Uremia and Uremic Toxins. Toxins (Basel) 2024; 16:227. [PMID: 38787079 PMCID: PMC11126090 DOI: 10.3390/toxins16050227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 05/12/2024] [Accepted: 05/14/2024] [Indexed: 05/25/2024] Open
Abstract
Uremia, also known as uremic syndrome, refers to the clinical symptoms in the final stage of renal failure. The definition of the term has changed over time due to an improved comprehension of the kidney's function and the advancement of dialysis technology. Here, we aim to present an overview of the various concepts that have developed regarding uremia throughout the years. We provide a comprehensive review of the historical progression starting from the early days of Kolff and his predecessors, continuing with the initial research conducted by Niwa et al., and culminating in the remote sensing hypothesis of Nigam. Additionally, we explore the subsequent investigation into the function of these toxins as signaling molecules in various somatic cells.
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Affiliation(s)
- Björn Meijers
- Nephrology and Transplantation Unit, University Hospitals Leuven, 30000 Leuven, Belgium; (B.M.); (W.Z.)
- Laboratory of Nephrology, Katholieke Universiteit Leuven, 30000 Leuven, Belgium
| | - Ward Zadora
- Nephrology and Transplantation Unit, University Hospitals Leuven, 30000 Leuven, Belgium; (B.M.); (W.Z.)
- Laboratory of Nephrology, Katholieke Universiteit Leuven, 30000 Leuven, Belgium
| | - Jerome Lowenstein
- Nephrology Division, NYU Langone Medical Center, New York, NY 10016, USA
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3
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Teng RD, Yang CH, Chung CL, Sheu JR, Hsieh CY. Attenuation of indoxyl sulfate-induced cell damage by cinchonidine-a Cinchona alkaloid-through the downregulation of p53 signaling pathway by promoting MDM2 cytoplasmic-nuclear shuttling in endothelial cells. Life Sci 2023; 318:121477. [PMID: 36796718 DOI: 10.1016/j.lfs.2023.121477] [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: 12/14/2022] [Revised: 01/28/2023] [Accepted: 02/02/2023] [Indexed: 02/16/2023]
Abstract
Renocardiac syndromes are a critical concern among patients with chronic kidney disease (CKD). High level of indoxyl sulfate (IS), a protein-bound uremic toxin, in plasma is known to promote the pathogenesis of cardiovascular diseases by impairing endothelial function. However, the therapeutic effects of the adsorbent of indole, a precursor of IS, on renocardiac syndromes is still debated. Therefore, novel therapeutic approaches should be developed to treat IS-associated endothelial dysfunction. In the present study, we have found that cinchonidine, a major Cinchona alkaloid, exhibited superior cell-protective effects among the 131 test compounds in IS-stimulated human umbilical vein endothelial cells (HUVECs). IS-induced cell death, cellular senescence, and impairment of tube formation in HUVECs were substantially reversed after treatment with cinchonidine. Despite the cinchonidine did not alter reactive oxygen species formation, cellular uptake of IS and OAT3 activity, RNA-Seq analysis showed that the cinchonidine treatment downregulated p53-modulated gene expression and substantially reversed IS-caused G0/G1 cell cycle arrest. Although the mRNA levels of p53 were not considerably downregulated by cinchonidine in IS-treated HUVECs, the treatment of cinchonidine promoted the degradation of p53 and the cytoplasmic-nuclear shuttling of MDM2. Cinchonidine exhibited cell-protective effects against the IS-induced cell death, cellular senescence, and impairment of vasculogenic activity in HUVECs through the downregulation of p53 signaling pathway. Collectively, cinchonidine may be a potential cell-protective agent to rescue IS-induced endothelial cell damage.
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Affiliation(s)
- Ruei-Dun Teng
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Chih-Hao Yang
- Department of Pharmacology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Chi-Li Chung
- Division of Pulmonary Medicine, Department of Internal Medicine, Taipei Medical University Hospital, Taipei, Taiwan; Division of Pulmonary Medicine, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; School of Respiratory Therapy, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Joen-Rong Sheu
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Pharmacology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Cheng-Ying Hsieh
- Department of Pharmacology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
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4
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Liu Y, Li G, Han Q, Lin H, Deng G, Li Q, Liu F. Designing adsorptive membranes for removing protein-bound uremic toxins via π-π and cation-π interaction. J Memb Sci 2023. [DOI: 10.1016/j.memsci.2023.121584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/15/2023]
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5
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Lidgard B, Bansal N, Zelnick LR, Hoofnagle A, Chen J, Colaizzo D, Dobre M, Mills KT, Porter AC, Rosas SE, Sarnak MJ, Seliger S, Sondheimer J, Tamura MK, Yaffe K, Kestenbaum B. Association of Proximal Tubular Secretory Clearance with Long-Term Decline in Cognitive Function. J Am Soc Nephrol 2022; 33:1391-1401. [PMID: 35444055 PMCID: PMC9257801 DOI: 10.1681/asn.2021111435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 04/05/2022] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND People with chronic kidney disease (CKD) are at high risk for cognitive impairment and progressive cognitive decline. Retention of protein-bound organic solutes that are normally removed by tubular secretion is hypothesized to contribute to cognitive impairment in CKD. METHODS We followed 2362 participants who were initially free of cognitive impairment and stroke in the prospective Chronic Renal Insufficiency Cohort (CRIC) Study. We estimated tubular secretory clearance by the 24-hour kidney clearances of eight endogenous solutes that are primarily eliminated by tubular secretion. CRIC study investigators assessed participants' cognitive function annually using the Modified Mini-Mental State (3MS) Examination. Cognitive decline was defined as a sustained decrease of more than five points in the 3MS score from baseline. Using Cox regression models adjusted for potential confounders, we analyzed associations between secretory solute clearances, serum solute concentrations, and cognitive decline. RESULTS The median number of follow-up 3MS examinations was six per participant. There were 247 incident cognitive decline events over a median of 9.1 years of follow-up. Lower kidney clearances of five of the eight secretory solutes (cinnamoylglycine, isovalerylglycine, kynurenic acid, pyridoxic acid, and tiglylglycine) were associated with cognitive decline after adjustment for baseline eGFR, proteinuria, and other confounding variables. Effect sizes ranged from a 17% to a 34% higher risk of cognitive decline per 50% lower clearance. In contrast, serum concentrations of the solutes were not associated with cognitive decline. CONCLUSIONS Lower kidney clearances of secreted solutes are associated with incident global cognitive decline in a prospective study of CKD, independent of eGFR. Further work is needed to determine the domains of cognition most affected by decreased secretory clearance and the mechanisms of these associations.
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Affiliation(s)
- Benjamin Lidgard
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington
| | - Nisha Bansal
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington
| | - Leila R. Zelnick
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington
| | - Andrew Hoofnagle
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington
| | - Jing Chen
- Department of Medicine, Tulane University, New Orleans, Louisiana
| | | | - Mirela Dobre
- Case Western Reserve University, University Hospitals Cleveland Medical Center, Cleveland, Ohio
| | | | - Anna C. Porter
- Department of Medicine, Section of Nephrology, University of Illinois at Chicago, Chicago, Illinois
| | - Sylvia E. Rosas
- Kidney and Hypertension Unit, Joslin Diabetes Center, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
| | - Mark J. Sarnak
- Department of Medicine, Tufts Medical Center, Boston, Massachusetts
| | - Stephen Seliger
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
| | - James Sondheimer
- Department of Medicine, Division of Nephrology, Wayne State University, Detroit, Michigan
| | - Manjula Kurella Tamura
- Department of Medicine, Stanford University and VA Palo Alto Health Care System, Palo Alto, California
| | - Kristine Yaffe
- Departments of Psychiatry, Neurology, Epidemiology and Biostatistics, School of Medicine, University of California, San Francisco, California
| | - Bryan Kestenbaum
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington
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6
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Järvinen E, Deng F, Kiander W, Sinokki A, Kidron H, Sjöstedt N. The Role of Uptake and Efflux Transporters in the Disposition of Glucuronide and Sulfate Conjugates. Front Pharmacol 2022; 12:802539. [PMID: 35095509 PMCID: PMC8793843 DOI: 10.3389/fphar.2021.802539] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 12/06/2021] [Indexed: 12/11/2022] Open
Abstract
Glucuronidation and sulfation are the most typical phase II metabolic reactions of drugs. The resulting glucuronide and sulfate conjugates are generally considered inactive and safe. They may, however, be the most prominent drug-related material in the circulation and excreta of humans. The glucuronide and sulfate metabolites of drugs typically have limited cell membrane permeability and subsequently, their distribution and excretion from the human body requires transport proteins. Uptake transporters, such as organic anion transporters (OATs and OATPs), mediate the uptake of conjugates into the liver and kidney, while efflux transporters, such as multidrug resistance proteins (MRPs) and breast cancer resistance protein (BCRP), mediate expulsion of conjugates into bile, urine and the intestinal lumen. Understanding the active transport of conjugated drug metabolites is important for predicting the fate of a drug in the body and its safety and efficacy. The aim of this review is to compile the understanding of transporter-mediated disposition of phase II conjugates. We review the literature on hepatic, intestinal and renal uptake transporters participating in the transport of glucuronide and sulfate metabolites of drugs, other xenobiotics and endobiotics. In addition, we provide an update on the involvement of efflux transporters in the disposition of glucuronide and sulfate metabolites. Finally, we discuss the interplay between uptake and efflux transport in the intestine, liver and kidneys as well as the role of transporters in glucuronide and sulfate conjugate toxicity, drug interactions, pharmacogenetics and species differences.
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Affiliation(s)
- Erkka Järvinen
- Clinical Pharmacology, Pharmacy, and Environmental Medicine, Department of Public Health, University of Southern Denmark, Odense, Denmark
| | - Feng Deng
- Department of Clinical Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Wilma Kiander
- Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Alli Sinokki
- Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Heidi Kidron
- Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Noora Sjöstedt
- Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
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7
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Cheung A, Ahmed A. Nonalcoholic Fatty Liver Disease and Chronic Kidney Disease: A Review of Links and Risks. Clin Exp Gastroenterol 2021; 14:457-465. [PMID: 34819740 PMCID: PMC8607580 DOI: 10.2147/ceg.s226130] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 10/21/2021] [Indexed: 12/13/2022] Open
Abstract
Nonalcoholic fatty liver disease and chronic kidney disease are both chronic conditions with rapidly increasing prevalence and incidence worldwide that have led to a significant burden on health-care systems. The association between these two disease entities is partly attributed to shared cardiometabolic comorbidities including diabetes, hypertension, obesity, and metabolic syndrome. However, independent of these overlapping risks, there are increased rates and more severe CKD in NAFLD patients. Conversely, more progressive NAFLD is seen with advanced stages of kidney injury. In addition to overlapping risk factors, shared pathogenic mechanisms suggest these two disease entities may resemble different manifestations of a single underlying disease process.
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Affiliation(s)
- Amanda Cheung
- Division of Gastroenterology and Hepatology, Stanford University School of Medicine, Stanford, CA, USA
| | - Aijaz Ahmed
- Division of Gastroenterology and Hepatology, Stanford University School of Medicine, Stanford, CA, USA
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8
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Maheshwari V, Tao X, Thijssen S, Kotanko P. Removal of Protein-Bound Uremic Toxins Using Binding Competitors in Hemodialysis: A Narrative Review. Toxins (Basel) 2021; 13:toxins13090622. [PMID: 34564626 PMCID: PMC8473190 DOI: 10.3390/toxins13090622] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 08/28/2021] [Accepted: 08/31/2021] [Indexed: 11/16/2022] Open
Abstract
Removal of protein-bound uremic toxins (PBUTs) during conventional dialysis is insufficient. PBUTs are associated with comorbidities and mortality in dialysis patients. Albumin is the primary carrier for PBUTs and only a small free fraction of PBUTs are dialyzable. In the past, we proposed a novel method where a binding competitor is infused upstream of a dialyzer into an extracorporeal circuit. The competitor competes with PBUTs for their binding sites on albumin and increases the free PBUT fraction. Essentially, binding competitor-augmented hemodialysis is a reactive membrane separation technique and is a paradigm shift from conventional dialysis therapies. The proposed method has been tested in silico, ex vivo, and in vivo, and has proven to be very effective in all scenarios. In an ex vivo study and a proof-of-concept clinical study with 18 patients, ibuprofen was used as a binding competitor; however, chronic ibuprofen infusion may affect residual kidney function. Binding competition with free fatty acids significantly improved PBUT removal in pre-clinical rat models. Based on in silico analysis, tryptophan can also be used as a binding competitor; importantly, fatty acids or tryptophan may have salutary effects in HD patients. More chemoinformatics research, pre-clinical, and clinical studies are required to identify ideal binding competitors before routine clinical use.
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Affiliation(s)
- Vaibhav Maheshwari
- Renal Research Institute, New York, NY 10065, USA; (X.T.); (S.T.); (P.K.)
- Correspondence:
| | - Xia Tao
- Renal Research Institute, New York, NY 10065, USA; (X.T.); (S.T.); (P.K.)
| | - Stephan Thijssen
- Renal Research Institute, New York, NY 10065, USA; (X.T.); (S.T.); (P.K.)
| | - Peter Kotanko
- Renal Research Institute, New York, NY 10065, USA; (X.T.); (S.T.); (P.K.)
- Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
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9
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Chronic Kidney Disease-Associated Itch (CKD-aI) in Children-A Narrative Review. Toxins (Basel) 2021; 13:toxins13070450. [PMID: 34209560 PMCID: PMC8309841 DOI: 10.3390/toxins13070450] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 06/26/2021] [Accepted: 06/28/2021] [Indexed: 01/08/2023] Open
Abstract
Chronic kidney disease (CKD) is a condition of widespread epidemiology and serious consequences affecting all organs of the organism and associated with significant mortality. The knowledge on CKD is rapidly evolving, especially concerning adults. Recently, more data is also appearing regarding CKD in children. Chronic itch (CI) is a common symptom appearing due to various underlying dermatological and systemic conditions. CI may also appear in association with CKD and is termed chronic kidney disease-associated itch (CKD-aI). CKD-aI is relatively well-described in the literature concerning adults, yet it also affects children. Unfortunately, the data on paediatric CKD-aI is particularly scarce. This narrative review aims to describe various aspects of CKD-aI with an emphasis on children, based on the available data in this population and the data extrapolated from adults. Its pathogenesis is described in details, focusing on the growing role of uraemic toxins (UTs), as well as immune dysfunction, altered opioid transmission, infectious agents, xerosis, neuropathy and dialysis-associated aspects. Moreover, epidemiological and clinical aspects are reviewed based on the few data on CKD-aI in children, whereas treatment recommendations are proposed as well, based on the literature on CKD-aI in adults and own experience in managing CI in children.
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10
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Chaves LD, Abyad S, Honan AM, Bryniarski MA, McSkimming DI, Stahura CM, Wells SC, Ruszaj DM, Morris ME, Quigg RJ, Yacoub R. Unconjugated p-cresol activates macrophage macropinocytosis leading to increased LDL uptake. JCI Insight 2021; 6:144410. [PMID: 33914709 PMCID: PMC8262368 DOI: 10.1172/jci.insight.144410] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 04/28/2021] [Indexed: 01/03/2023] Open
Abstract
Patients with chronic kidney disease (CKD) and end-stage renal disease suffer from increased cardiovascular events and cardiac mortality. Prior studies have demonstrated that a portion of this enhanced risk can be attributed to the accumulation of microbiota-derived toxic metabolites, with most studies focusing on the sulfonated form of p-cresol (PCS). However, unconjugated p-cresol (uPC) itself was never assessed due to rapid and extensive first-pass metabolism that results in negligible serum concentrations of uPC. These reports thus failed to consider the host exposure to uPC prior to hepatic metabolism. In the current study, not only did we measure the effect of altering the intestinal microbiota on lipid accumulation in coronary arteries, but we also examined macrophage lipid uptake and handling pathways in response to uPC. We found that atherosclerosis-prone mice fed a high-fat diet exhibited significantly higher coronary artery lipid deposits upon receiving fecal material from CKD mice. Furthermore, treatment with uPC increased total cholesterol, triglycerides, and hepatic and aortic fatty deposits in non-CKD mice. Studies employing an in vitro macrophage model demonstrated that uPC exposure increased apoptosis whereas PCS did not. Additionally, uPC exhibited higher potency than PCS to stimulate LDL uptake and only uPC induced endocytosis- and pinocytosis-related genes. Pharmacological inhibition of varying cholesterol influx and efflux systems indicated that uPC increased macrophage LDL uptake by activating macropinocytosis. Overall, these findings indicate that uPC itself had a distinct effect on macrophage biology that might have contributed to increased cardiovascular risk in patients with CKD.
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Affiliation(s)
- Lee D Chaves
- Department of Medicine, Division of Nephrology, Jacobs School of Medicine and Biomedical Sciences, and.,Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, University at Buffalo, Buffalo, New York, USA
| | - Sham Abyad
- Department of Medicine, Division of Nephrology, Jacobs School of Medicine and Biomedical Sciences, and
| | - Amanda M Honan
- Department of Medicine, Division of Nephrology, Jacobs School of Medicine and Biomedical Sciences, and
| | - Mark A Bryniarski
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, University at Buffalo, Buffalo, New York, USA
| | - Daniel I McSkimming
- Department of Medicine, Bioinformatics and Computational Biology Core, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Corrine M Stahura
- Department of Medicine, Division of Nephrology, Jacobs School of Medicine and Biomedical Sciences, and
| | - Steven C Wells
- Department of Medicine, Division of Nephrology, Jacobs School of Medicine and Biomedical Sciences, and
| | - Donna M Ruszaj
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, University at Buffalo, Buffalo, New York, USA
| | - Marilyn E Morris
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, University at Buffalo, Buffalo, New York, USA
| | - Richard J Quigg
- Department of Medicine, Division of Nephrology, Jacobs School of Medicine and Biomedical Sciences, and
| | - Rabi Yacoub
- Department of Medicine, Division of Nephrology, Jacobs School of Medicine and Biomedical Sciences, and
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11
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Cheng BC, Lai YR, Huang CC, Lu CH. Improved cardiovascular autonomic function and decreased protein-bound uremic toxins in patients with end-stage renal disease after peritoneal dialysis. J Int Med Res 2021; 48:300060520933797. [PMID: 32692275 PMCID: PMC7375729 DOI: 10.1177/0300060520933797] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Objective Cardiovascular autonomic neuropathy is highly prevalent in patients with end-stage renal disease (ESRD), and it has a high fatality rate. This study aimed to determine whether peritoneal dialysis (PD) improves cardiovascular autonomic function (CAF) and decreases protein-bound uremic toxin (indoxyl sulfate [IS], p-cresyl sulfate [PCS]) levels. Methods IS and PCS levels, and parameters of CAF (heart rate response to deep breathing [HR_DB], the Valsalva ratio, baroreflex sensitivity, and the frequency domain) were prospectively evaluated in 26 patients with ESRD undergoing PD at two time points (pre-PD and 6 months post-PD). For comparison, 19 consecutive patients with pre-dialysis chronic kidney disease and 30 age- and sex-matched healthy volunteers were included as the disease and control groups, respectively. Results Baroreflex sensitivity, HR_DB, and the Valsalva ratio were significantly lower in the ESRD and disease groups than in the control group. IS and PCS levels were significantly higher in the ESRD group than in the control group. Sympathetic/parasympathetic activity was improved after PD. IS levels were significantly decreased after PD and IS level changes were correlated with the frequency domain. Conclusions IS may play a role in cardiovascular autonomic neuropathy, and decreased IS levels after dialysis are associated with sympathetic/parasympathetic activity imbalance.
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Affiliation(s)
- Ben-Chung Cheng
- Department of Biological Science, National Sun Yat-Sen University, Kaohsiung.,Division of Nephrology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung
| | - Yun-Ru Lai
- Department of Biological Science, National Sun Yat-Sen University, Kaohsiung.,Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung
| | - Chih-Cheng Huang
- Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung
| | - Cheng-Hsien Lu
- Department of Biological Science, National Sun Yat-Sen University, Kaohsiung.,Division of Nephrology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung.,Center for Shockwave Medicine and Tissue Engineering, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung.,Department of Neurology, Xiamen Chang Gung Memorial Hospital, Xiamen, Fujian, China
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12
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Ludwig J, Smith J, Pfaendtner J. Analyzing the Long Time-Scale Dynamics of Uremic Toxins Bound to Sudlow Site II in Human Serum Albumin. J Phys Chem B 2021; 125:2910-2920. [PMID: 33715376 DOI: 10.1021/acs.jpcb.1c00221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Protein bound uremic toxins (PBUTs), a series of chemicals that remain a challenge for removal strategies used on patients suffering with chronic kidney disease, could be strong candidates for MD study in order to better understand the interactions and time scales associated with binding mode transitions. Currently, traditional dialysis methods cannot satisfactorily remove PBUTs from the bloodstream. This is at least partly due to these toxin's high level of affinity for protein binding sites, particularly the prominent human serum albumin (HSA) and two of its drug binding sites (Sudlow site I and II). We investigate the dynamics of binding site transitions and interactions by MD simulations targeting four well-known toxins: indoxyl sulfate (IS), p-cresyl sulfate (PCS), indole-3-acetic acid (IAA), and hippurate acid (HIP). Long-time scale dynamics are obtained by the use of time-structure independent component analysis (tICA) for dimensionality reduction followed by spectral analysis of a Markov state model (MSM) scored using the generalized matrix Rayleigh quotient (GMRQ). Our results add new insights to prior findings related to the key role of charge-pairing in governing toxin-protein interactions. We find that IAA, the bulkiest hydrophobic toxin studied, observes the slowest process of at least 3 times slower than the smaller, less hydrophobic toxins. In general, we find that the processes slower than 15 ns are correlated with a transition from dominantly hydrophobic interactions deep in the binding pocket to a gain in hydrogen bonding partners near the mouth of the pocket. Our results indicate that aromatic residues such as PHE play a part in a type of toxin stabilization akin to π-stacking. In conclusion, this work presents mechanistic descriptions of interactions/transitions for a set of important PBUTs that bind Sudlow site II on time scales relevant to the underlying binding kinetics of most interest.
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Affiliation(s)
- James Ludwig
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Josh Smith
- Department of Chemical Engineering, University of Washington, Seattle, Washington 98195-1750, United States
| | - Jim Pfaendtner
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States.,Department of Chemical Engineering, University of Washington, Seattle, Washington 98195-1750, United States
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13
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Daneshamouz S, Eduok U, Abdelrasoul A, Shoker A. Protein-bound uremic toxins (PBUTs) in chronic kidney disease (CKD) patients: Production pathway, challenges and recent advances in renal PBUTs clearance. NANOIMPACT 2021; 21:100299. [PMID: 35559786 DOI: 10.1016/j.impact.2021.100299] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 01/13/2021] [Accepted: 01/20/2021] [Indexed: 06/15/2023]
Abstract
Uremic toxins, a group of uremic retention solutes with high concentration which their accumulation on the body makes several biological problems, have recently gained a large interest. The importance of this issue more targets patients with compromised kidney function since the presence of these toxins in their bodies contributes to serious illness and death. It is reported that around 14% of people are subjected of CKD's problems. Among different classifications of uremic toxins, protein bound uremic toxins are poorly removed from the body as they tightly bind to proteins like serum albumin. A deeper and closer understanding of methods for removing protein bound uremic toxins and their efficiency is of paramount importance. This article discussed the most critical protein bound uremic toxins from different points of view including their chemistry, binding sites, interactions, and their biological impacts. Concerning the toxicity and high concentration, p-cresyl sulfate (PCS), Indoxyl sulfate (IS), 3-Carboxy-4-methyl-5-propyl-2-furanpropionic acid (CMPF), and Indole- 3-acetic acid (IAA) was chosen to study in this article. Results offered that the functional groups of mentioned PBUTs and the way that they interact with the adsorbent play an important role in finding substances for removal of them. Furthermore, the development of nanoparticle (NPs) for promising biomedical purposes has been explored. However, there is still a need for further investigation to find biocompatible substances focusing on the removal of PBUTs. PBUTs are a unique class of uremic toxins whose renal clearance mechanisms and role in uremic pathophysiology are still unclear. This review outlines the biochemical aspects of PBUT/protein binding in a view to explaining their renal formation to elimination mechanisms; some examples are drawn from routes involving albumin-binding with indoxyl sulphate, p-cresyl sulfate, p-cresyl glucuronide and hippuric acid. We have also highlighted the kinetic behaviors during dialytic removal of PBUTs to address future concerns regarding dialytic therapy.
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Affiliation(s)
- Sana Daneshamouz
- Department of Chemical and Biological Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, Saskatchewan S7N 5A9, Canada
| | - Ubong Eduok
- Department of Chemical and Biological Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, Saskatchewan S7N 5A9, Canada
| | - Amira Abdelrasoul
- Department of Chemical and Biological Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, Saskatchewan S7N 5A9, Canada; Department of Biomedical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, Saskatchewan S7N 5A9, Canada.
| | - Ahmed Shoker
- Nephrology Division, College of Medicine, University of Saskatchewan, 107 Wiggins Rd, Saskatoon, SK S7N 5E5, Canada; Saskatchewan Transplant Program, St. Paul's Hospital, 1702 20th Street West Saskatoon Saskatchewan S7M 0Z9, Canada
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14
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Ma YR, Xin MY, Li K, Wang H, Rao Z, Liu TX, Wu XA. An LC-MS/MS analytical method for the determination of uremic toxins in patients with end-stage renal disease. J Pharm Biomed Anal 2020; 191:113551. [PMID: 32889350 DOI: 10.1016/j.jpba.2020.113551] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 08/09/2020] [Accepted: 08/10/2020] [Indexed: 12/18/2022]
Abstract
End-stage renal disease (ESRD) is the last stage of chronic kidney disease, characterized by the progressive accumulation of uremic toxins (UTs). Hemodialysis is the standard approach to remove UTs from the body. Creatinine and urea levels are important indices of hemodialysis effectiveness, but the utility of those markers to estimate the removal of UTs, especially protein-binding UTs is limited. We developed an LC-MS/MS method for the quantification of UTs and to provide markers for evaluating hemodialysis effectiveness. These substances were extracted from serum samples after acetonitrile precipitation of protein and then separated on a HILIC column. The flow rate was 0.6 mL/min with a run time of 8.0 min for the negative ion mode and positive ion mode each. In this study 26 UTs were determined in normal subjects and in patients with ESRD before and after hemodialysis; serum levels were significantly higher in patients with ESRD than in subjects with normal renal function. A significant decrease in a variety of serum UTs were observed in patients after dialysis treatment, but no change in the levels of orotic acid, CMPF, kynurenic acid, p-cresol sulfate, phenyl-β-d-glucuronide, 4-ethylphenyl sulfate and 3-indolyl-β-d-glucopyranoside was found. These results show that some UTs could not be completely removed by hemodialysis. In addition, some biomarkers of different types of UTs are proposed for evaluating hemodialysis effectiveness.
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Affiliation(s)
- Yan-Rong Ma
- School of Pharmacy, Lanzhou University, Lanzhou 730000, China; Department of Pharmacy, the First Hospital of Lanzhou University, Lanzhou 730000 China
| | - Ming-Yan Xin
- School of Pharmacy, Lanzhou University, Lanzhou 730000, China
| | - Kan Li
- Department of Nephrology, the First Hospital of Lanzhou University, Lanzhou 730000 China
| | - Huan Wang
- School of Pharmacy, Lanzhou University, Lanzhou 730000, China
| | - Zhi Rao
- Department of Pharmacy, the First Hospital of Lanzhou University, Lanzhou 730000 China
| | - Tian-Xi Liu
- Department of Nephrology, the First Hospital of Lanzhou University, Lanzhou 730000 China.
| | - Xin-An Wu
- School of Pharmacy, Lanzhou University, Lanzhou 730000, China; Department of Pharmacy, the First Hospital of Lanzhou University, Lanzhou 730000 China.
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15
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Abe T, Onoda M, Matsuura T, Sugimura J, Obara W, Sasaki N, Kato T, Tatsumi K, Maruyama T. Evaluation of a new measurement method of indoxyl sulfate in hemodialysis patients. Ther Apher Dial 2020; 25:44-49. [PMID: 32281288 DOI: 10.1111/1744-9987.13500] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 04/05/2020] [Accepted: 04/10/2020] [Indexed: 11/29/2022]
Abstract
Indoxyl sulfate (IS) is related to the development of cardiovascular disease and total mortality in dialysis patients. High-performance liquid chromatography (HPLC) is the conventional measurement approach. However, the HPLC method is difficult to perform in real time. Recently, the IS Assay Kit "NIPRO", which enables the measuring of total IS by the enzyme method, was developed. This new reagent allows the easy and quick measurement of many samples using the automatic biochemical analyzer. Moreover, it was reported that it demonstrated satisfactory analytical performance. If this enzyme method is useful for measuring IS in hemodialysis, we can expect that the mechanism in which the IS effects adversely on a body as uremic toxins will be clarified. However, the enzyme method is more easily influenced by other coexisting substances. In this study, we have assessed on how the uremic toxins and anticoagulation effect on this new reagent and evaluate whether it can be put into practice effectively for hemodialysis patients. For the enzyme method, accuracy, simultaneous repeatability, linearity, limit of detection, influence of coexisting materials, and correlation with the HPLC method were examined. Accuracy and simultaneous repeatability were satisfactory, and linearity was good. The limit of detection was acceptable, and there was no influence of coexisting materials. With regard to the correlation, the regression equation was y = 0.947X + 7.987 and the correlation coefficient (r) was 0.972. This new reagent showed sufficient fundamental performance and had a good correlation with the conventional HPLC method for assessing the plasma of dialysis patients.
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Affiliation(s)
- Takaya Abe
- Department of Urology, Iwate Medical University, School of Medicine, Morioka, Japan
| | - Mitsutaka Onoda
- Department of Urology, Iwate Medical University, School of Medicine, Morioka, Japan
| | - Tomohiko Matsuura
- Department of Urology, Iwate Medical University, School of Medicine, Morioka, Japan
| | - Jun Sugimura
- Department of Urology, Iwate Medical University, School of Medicine, Morioka, Japan
| | - Wataru Obara
- Department of Urology, Iwate Medical University, School of Medicine, Morioka, Japan
| | - Nariyuki Sasaki
- Dialysis Center, Seitetsu Memorial Hospital, Kamaishi, Japan
| | - Tetsuo Kato
- Dialysis Center, Seitetsu Memorial Hospital, Kamaishi, Japan
| | - Kenta Tatsumi
- Department III, Research & Development Laboratory, Medical Technology for Planning, Development & Marketing, Nipro Corporation, Kusatsushi, Japan
| | - Toru Maruyama
- Department of Biopharmaceutics, Kumamoto University, Graduate School of Pharmaceutical Sciences, School of Pharmacy, Kumamoto, Japan
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16
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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: 31] [Impact Index Per Article: 7.8] [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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17
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Wang K, Nguyen M, Chen Y, Hoofnagle AN, Becker JO, Zelnick LR, Kundzins J, Goodling A, Himmelfarb J, Kestenbaum B. Association of Tubular Solute Clearance with Symptom Burden in Incident Peritoneal Dialysis. Clin J Am Soc Nephrol 2020; 15:530-538. [PMID: 32152064 PMCID: PMC7133131 DOI: 10.2215/cjn.11120919] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Accepted: 02/07/2020] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Residual kidney function is important to the health and wellbeing of patients with ESKD. We tested whether the kidney clearances of proximal tubular secretory solutes are associated with burden of uremic and heart failure symptoms among patients on peritoneal dialysis with residual kidney function. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We enrolled 29 patients on incident peritoneal dialysis with residual urine output >250 ml daily. We used targeted liquid chromatography-mass spectrometry to quantify plasma, 24-hour urine, and peritoneal dialysate concentrations of ten tubular secretory solutes. We calculated the kidney and peritoneal dialysis clearances of each secretory solute, creatinine, and urea, and we estimated a composite kidney and peritoneal secretion score. We assessed for uremic symptoms using the Dialysis Symptom Index and heart failure-related symptoms using the Kansas City Cardiomyopathy Questionnaire. We used linear regression to determine associations of composite secretory solute clearances and GFRurea+Cr with Dialysis Symptom Index symptom score and Kansas City Cardiomyopathy Questionnaire summary score. RESULTS Mean residual kidney clearances of creatinine and urea were 8±5 and 9±6 ml/min per 1.73 m2, respectively, and mean GFRurea+Cr was 8±5 ml/min per 1.73 m2. The residual kidney clearances of most secretory solutes were considerably higher than creatinine and urea clearance, and also, they were higher than their respective peritoneal dialysis clearances. After adjustments for age and sex, each SD higher composite kidney secretion score was associated with an 11-point lower Dialysis Symptom Index score (95% confidence interval, -20 to -1; P=0.03) and a 12-point higher Kansas City Cardiomyopathy Questionnaire score (95% confidence interval, 0.5- to 23-point higher score; P=0.04). Composite peritoneal dialysis secretion score was not associated with either symptom assessment. CONCLUSIONS Residual kidney clearances of secretory solutes are higher than peritoneal dialysis clearances. Kidney clearances of secretory solutes are associated with patient-reported uremic and heart failure-related symptoms.
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Affiliation(s)
- Ke Wang
- Division of Nephrology, Department of Medicine, University of Washington, Seattle Washington; .,Division of Nephrology, Department of Medicine, University of Washington, Kidney Research Institute, Seattle, Washington
| | - Michelle Nguyen
- Division of Nephrology, Department of Medicine, University of Washington, Kidney Research Institute, Seattle, Washington
| | - Yan Chen
- Division of Nephrology, Department of Medicine, University of Washington, Kidney Research Institute, Seattle, Washington.,Department of Epidemiology, University of Washington, Seattle Washington; and
| | - Andrew N Hoofnagle
- Division of Nephrology, Department of Medicine, University of Washington, Kidney Research Institute, Seattle, Washington.,Department of Laboratory Medicine, University of Washington, Seattle, Washington
| | - Jessica O Becker
- Department of Laboratory Medicine, University of Washington, Seattle, Washington
| | - Leila R Zelnick
- Division of Nephrology, Department of Medicine, University of Washington, Seattle Washington.,Division of Nephrology, Department of Medicine, University of Washington, Kidney Research Institute, Seattle, Washington
| | - John Kundzins
- Division of Nephrology, Department of Medicine, University of Washington, Kidney Research Institute, Seattle, Washington.,Department of Epidemiology, University of Washington, Seattle Washington; and
| | - Anne Goodling
- Division of Nephrology, Department of Medicine, University of Washington, Kidney Research Institute, Seattle, Washington
| | - Jonathan Himmelfarb
- Division of Nephrology, Department of Medicine, University of Washington, Seattle Washington.,Division of Nephrology, Department of Medicine, University of Washington, Kidney Research Institute, Seattle, Washington
| | - Bryan Kestenbaum
- Division of Nephrology, Department of Medicine, University of Washington, Seattle Washington.,Division of Nephrology, Department of Medicine, University of Washington, Kidney Research Institute, Seattle, Washington
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18
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Carracedo J, Alique M, Vida C, Bodega G, Ceprián N, Morales E, Praga M, de Sequera P, Ramírez R. Mechanisms of Cardiovascular Disorders in Patients With Chronic Kidney Disease: A Process Related to Accelerated Senescence. Front Cell Dev Biol 2020; 8:185. [PMID: 32266265 PMCID: PMC7099607 DOI: 10.3389/fcell.2020.00185] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 03/05/2020] [Indexed: 01/08/2023] Open
Abstract
Cardiovascular diseases (CVDs), especially those involving a systemic inflammatory process such as atherosclerosis, remain the leading cause of morbidity and mortality in patients with chronic kidney disease (CKD). CKD is a systemic condition affecting approximately 10% of the general population. The prevalence of CKD has increased over the past decades because of the aging of the population worldwide. Indeed, CVDs in patients with CKD constitute a premature form of CVD observed in the general population. Multiple studies indicate that patients with renal disease undergo accelerated aging, which precipitates the appearance of pathologies, including CVDs, usually associated with advanced age. In this review, we discuss several aspects that characterize CKD-associated CVDs, such as etiopathogenic elements that CKD patients share with the general population, changes in the cellular balance of reactive oxygen species (ROS), and the associated process of cellular senescence. Uremia-associated aging is linked with numerous changes at the cellular and molecular level. These changes are similar to those observed in the normal process of physiologic aging. We also discuss new perspectives in the study of CKD-associated CVDs and epigenetic alterations in intercellular signaling, mediated by microRNAs and/or extracellular vesicles (EVs), which promote vascular damage and subsequent development of CVD. Understanding the processes and factors involved in accelerated senescence and other abnormal intercellular signaling will identify new therapeutic targets and lead to improved methods of diagnosis and monitoring for patients with CKD-associated CVDs.
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Affiliation(s)
- Julia Carracedo
- Departamento de Genética, Fisiología y Microbiología, Universidad Complutense/Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), Madrid, Spain
| | - Matilde Alique
- Departamento Biología de Sistemas, Facultad de Medicina y Ciencias de la Salud (IRYCIS), Universidad de Alcalá, Alcalá de Henares, Madrid, Spain
| | - Carmen Vida
- Departamento Biología de Sistemas, Facultad de Medicina y Ciencias de la Salud (IRYCIS), Universidad de Alcalá, Alcalá de Henares, Madrid, Spain
| | - Guillermo Bodega
- Departamento de Biomedicina y Biotecnología, Facultad de Biología, Química y Ciencias Ambientales, Universidad de Alcalá, Alcalá de Henares, Spain
| | - Noemí Ceprián
- Departamento de Genética, Fisiología y Microbiología, Universidad Complutense/Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), Madrid, Spain
| | - Enrique Morales
- Departamento de Nefrología, Hospital Universitario 12 de Octubre/Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), Madrid, Spain.,Departamento de Medicina, Universidad Complutense de Madrid, Madrid, Spain
| | - Manuel Praga
- Departamento de Nefrología, Hospital Universitario 12 de Octubre/Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), Madrid, Spain.,Departamento de Medicina, Universidad Complutense de Madrid, Madrid, Spain
| | - Patricia de Sequera
- Departamento de Medicina, Universidad Complutense de Madrid, Madrid, Spain.,Sección de Nefrología, Hospital Universitario Infanta Leonor, Madrid, Spain
| | - Rafael Ramírez
- Departamento Biología de Sistemas, Facultad de Medicina y Ciencias de la Salud (IRYCIS), Universidad de Alcalá, Alcalá de Henares, Madrid, Spain
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19
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Novel dietary and pharmacologic approaches for acid–base modulation to preserve kidney function and manage uremia. Curr Opin Nephrol Hypertens 2020; 29:39-48. [DOI: 10.1097/mnh.0000000000000568] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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20
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Abstract
The gut microbiota has been implicated in the pathogenesis and progression of kidney disease. However, little is known about the gut microbiota in hemodialysis (HD) patients. We assessed the gut microbiota and its relationship with clinical variables in ten HD patients. We found that the Firmicutes-to-Bacteroidetes ratio was positively associated with traditional risk factors for cardiovascular disease. Furthermore, Faecalibacterium was positively associated with carbohydrate intake and negatively associated with arterial stiffness. Finally, endotoxemia was inversely associated with butyrate producers. Future studies should assess if targeting the gut microbiota result in a lower burden for cardiovascular disease in HD patients.
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21
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Bryniarski MA, Hamarneh F, Yacoub R. The role of chronic kidney disease-associated dysbiosis in cardiovascular disease. Exp Biol Med (Maywood) 2019; 244:514-525. [PMID: 30682892 PMCID: PMC6547008 DOI: 10.1177/1535370219826526] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
IMPACT STATEMENT Negative alterations, or dysbiosis, in the intestinal microbial community balance in response to chronic kidney disease is emerging as a substantial and important factor in inducing and exacerbating multiple comorbid conditions. Patients with renal insufficiency experience a substantial increase in cardiovascular risk, and recent evidence is shedding light on the close interaction between microbiome dysbiosis and increased cardiovascular events in this population. Previous association and recent causality studies utilizing experimental animal models have enriched our understanding and confirmed the impact of microbial community imbalance on cardiac health in both the general population and in patients with renal impairment.
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Affiliation(s)
- Mark A Bryniarski
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, University at Buffalo, Buffalo, NY 14214, USA
| | - Fares Hamarneh
- University College Dublin School of Medicine and Medical Science, Dublin, Ireland
- Department of Internal Medicine, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14203, USA
| | - Rabi Yacoub
- Department of Internal Medicine, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14203, USA
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22
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Madero M, Cano KB, Campos I, Tao X, Maheshwari V, Brown J, Cornejo B, Handelman G, Thijssen S, Kotanko P. Removal of Protein-Bound Uremic Toxins during Hemodialysis Using a Binding Competitor. Clin J Am Soc Nephrol 2019; 14:394-402. [PMID: 30755453 PMCID: PMC6419294 DOI: 10.2215/cjn.05240418] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 01/03/2019] [Indexed: 12/21/2022]
Abstract
BACKGROUND AND OBJECTIVES Current hemodialysis techniques fail to efficiently remove the protein-bound uremic toxins p-cresyl sulfate and indoxyl sulfate due to their high degree of albumin binding. Ibuprofen, which shares the same primary albumin binding site with p-cresyl sulfate and indoxyl sulfate, can be infused during hemodialysis to displace these toxins, thereby augmenting their removal. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We infused 800 mg ibuprofen into the arterial bloodline between minutes 21 and 40 of a conventional 4-hour high-flux hemodialysis treatment. We measured arterial, venous, and dialysate outlet concentrations of indoxyl sulfate, p-cresyl sulfate, tryptophan, ibuprofen, urea, and creatinine before, during, and after the ibuprofen infusion. We report clearances of p-cresyl sulfate and indoxyl sulfate before and during ibuprofen infusion and dialysate concentrations of protein-bound uremic toxins normalized to each patient's average preinfusion concentrations. RESULTS We studied 18 patients on maintenance hemodialysis: age 36±11 years old, ten women, and mean vintage of 37±37 months. Compared with during the preinfusion period, the median (interquartile range) clearances of indoxyl sulfate and p-cresyl sulfate increased during ibuprofen infusion from 6.0 (6.5) to 20.2 (27.1) ml/min and from 4.4 (6.7) to 14.9 (27.1) ml/min (each P<0.001), respectively. Relative median (interquartile range) protein-bound uremic toxin dialysate outlet levels increased from preinfusion 1.0 (reference) to 2.4 (1.2) for indoxyl sulfate and to 2.4 (1.0) for p-cresyl sulfate (each P<0.001). Although median serum post- and predialyzer levels in the preinfusion period were similar, infusion led to a marked drop in serum postdialyzer levels for both indoxyl sulfate and p-cresyl sulfate (-1.0 and -0.3 mg/dl, respectively; each P<0.001). The removal of the nonprotein-bound solutes creatinine and urea was not increased by the ibuprofen infusion. CONCLUSIONS Infusion of ibuprofen into the arterial bloodline during hemodialysis significantly increases the dialytic removal of indoxyl sulfate and p-cresyl sulfate and thereby, leads to greater reduction in their serum levels.
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Affiliation(s)
- Magdalena Madero
- Division of Nephrology, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad de Mexico, Mexico
| | - Karla B. Cano
- Division of Nephrology, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad de Mexico, Mexico
| | - Israel Campos
- Renal Research Institute, Research Division, New York, New York
| | - Xia Tao
- Renal Research Institute, Research Division, New York, New York
| | | | - Jillian Brown
- Biomedical and Nutritional Sciences, University of Massachusetts, Lowell, Massachusetts; and
| | - Beatriz Cornejo
- Division of Nephrology, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad de Mexico, Mexico
| | - Garry Handelman
- Biomedical and Nutritional Sciences, University of Massachusetts, Lowell, Massachusetts; and
| | | | - Peter Kotanko
- Renal Research Institute, Research Division, New York, New York
- Department of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York
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23
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In silico comparison of protein-bound uremic toxin removal by hemodialysis, hemodiafiltration, membrane adsorption, and binding competition. Sci Rep 2019; 9:909. [PMID: 30696874 PMCID: PMC6351554 DOI: 10.1038/s41598-018-37195-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 12/04/2018] [Indexed: 11/19/2022] Open
Abstract
Protein-bound uremic toxins (PBUTs) are poorly removed during hemodialysis (HD) due to their low free (dialyzable) plasma concentration. We compared PBUT removal between HD, hemodiafiltration (HDF), membrane adsorption, and PBUT displacement in HD. The latter involves infusing a binding competitor pre-dialyzer, which competes with PBUTs for their albumin binding sites and increases their free fraction. We used a mathematical model of PBUT/displacer kinetics in dialysis comprising a three-compartment patient model, an arterial/venous tube segment model, and a dialyzer model. Compared to HD, improvements in removal of prototypical PBUTs indoxyl sulfate (initial concentration 100 µM, 7% free) and p-cresyl sulfate (150 µM, 5% free) were: 5.5% and 6.4%, respectively, for pre-dilution HDF with 20 L replacement fluid; 8.1% and 9.1% for post-dilution HDF 20 L; 15.6% and 18.3% for pre-dilution HDF 60 L; 19.4% and 22.2% for complete membrane adsorption; 35.0% and 41.9% for displacement with tryptophan (2000 mg in 500 mL saline); 26.7% and 32.4% for displacement with ibuprofen (800 mg in 200 mL saline). Prolonged (one-month) use of tryptophan reduces the IS and pCS time-averaged concentration by 28.1% and 29.9%, respectively, compared to conventional HD. We conclude that competitive binding can be a pragmatic approach for improving PBUT removal.
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24
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Hou YC, Lu CL, Zheng CM, Chen RM, Lin YF, Liu WC, Yen TH, Chen R, Lu KC. Emerging Role of Vitamins D and K in Modulating Uremic Vascular Calcification: The Aspect of Passive Calcification. Nutrients 2019; 11:E152. [PMID: 30642029 PMCID: PMC6356797 DOI: 10.3390/nu11010152] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 12/19/2018] [Accepted: 01/08/2019] [Indexed: 01/06/2023] Open
Abstract
Vascular calcification is a critical complication in patients with chronic kidney disease (CKD) because it is predictive of cardiovascular events and mortality. In addition to the traditional mechanisms associated with endothelial dysfunction and the osteoblastic transformation of vascular smooth muscle cells (VSMCs), the regulation of calcification inhibitors, such as calciprotein particles (CPPs) and matrix vesicles plays a vital role in uremic vascular calcification in CKD patients because of the high prevalence of vitamin K deficiency. Vitamin K governs the gamma-carboxylation of matrix Gla protein (MGP) for inhibiting vascular calcification, and the vitamin D binding protein receptor is related to vitamin K gene expression. For patients with chronic kidney disease, adequate use of vitamin D supplements may play a role in vascular calcification through modulation of the calciprotein particles and matrix vesicles (MVs).
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Affiliation(s)
- Yi-Chou Hou
- Department of Internal Medicine, Cardinal Tien Hospital, School of Medicine, Fu-Jen Catholic University, New Taipei City 23148, Taiwan.
- College of Medicine, Fu-Jen Catholic University, New Taipei City 24205, Taiwan.
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.
| | - Chien-Lin Lu
- College of Medicine, Fu-Jen Catholic University, New Taipei City 24205, Taiwan.
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.
- Division of Nephrology, Department of Medicine, Fu Jen Catholic University Hospital, School of Medicine, Fu Jen Catholic University, New Taipei City 24205, Taiwan.
| | - Cai-Mei Zheng
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.
- Division of Nephrology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City 23561, Taiwan.
| | - Ruei-Ming Chen
- Graduate Institute of Medical Sciences, College of Medicine, Research Center of Cancer Translational Medicine, Taipei Medical University, Taipei 11031, Taiwan.
- Anesthesiology and Health Policy Research Center, Taipei Medical University Hospital, Taipei 11031, Taiwan.
- Brain Disease Research Center, Wan-Fang Hospital, Taipei Medical University, Taipei 11031, Taiwan.
| | - Yuh-Feng Lin
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.
- Division of Nephrology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City 23561, Taiwan.
- Division of Nephrology, Department of Internal Medicine, Tri-Service General Hospital, Taipei 11490, Taiwan.
| | - Wen-Chih Liu
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.
- Division of Nephrology, Department of Internal Medicine, Tungs' Taichung MetroHarbor Hospital, Taichung City 435, Taiwan.
| | - Tzung-Hai Yen
- Department of Nephrology, Chang Gung Memorial Hospital and College of Medicine, Chang Gung University, Taoyuan City 33305, Taiwan.
- Kidney Research Center, Chang Gung Memorial Hospital, Taoyuan City 33305, Taiwan.
- Center for Tissue Engineering, Chang Gung Memorial Hospital, Taoyuan City 33305, Taiwan.
| | - Remy Chen
- Kidney Dialysis Center, Kamifukuoka General Hospital, Saitama 356, Japan.
| | - Kuo-Cheng Lu
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.
- Division of Nephrology, Department of Medicine, Fu Jen Catholic University Hospital, School of Medicine, Fu Jen Catholic University, New Taipei City 24205, Taiwan.
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25
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Shen-Shuai-Ning granule decreased serum concentrations of indoxyl sulphate in uremic patients undergoing peritoneal dialysis. Biosci Rep 2018; 38:BSR20171694. [PMID: 29921575 PMCID: PMC6137246 DOI: 10.1042/bsr20171694] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 04/23/2018] [Accepted: 06/19/2018] [Indexed: 12/02/2022] Open
Abstract
Clearance of protein-bound uremic toxins (PBUTs) by dialysis is a challenge in the treatment of uremic patients. Shen-Shuai-Ning (SSN), a traditional Chinese medicine formulation, has been used commonly in China to retard kidney disease progression and decrease uremic toxins in chronic kidney disease (CKD) patients, but the effects of SSN on serum PBUTs in dialysis patients were not investigated. We conducted a randomized controlled trial in patients on peritoneal dialysis (PD) at dialysis center of Changzheng Hospital to evaluate the effects of SSN on serum PBUTs. Participants with SSN intervention took 5 g SSN granule three times daily for 12 weeks, while the baseline medications and dialysis prescriptions remained during the study in all patients. The serum concentrations of indoxyl sulphate (IS) and p-cresol sulphate (PCS) were determined by HPLC/MS/MS and biochemical parameters were assessed during the study. Sixty PD patients were enrolled and randomly allocated into SSN group and control group. Total IS level was significantly lower in SSN group than in control group at week 4, 8, and 12 (27.28 ± 18.19, 29.73 ± 19.10, and 29.41 ± 17.61 mg/l compared with 39.25 ± 20.23, 44.86 ± 23.91, and 45.34 ± 33.52 mg/l, respectively). However, there were no statistical difference of total PCS, free forms of IS and PCS concentrations between SSN group and control group during 12 weeks follow-up. Administration of SSN granule orally decreased serum total IS level effectively in uremic patients on PD with good tolerance. Benefits of PD patients’ outcomes from IS reduction by SSN awaits further large size and long duration clinical trials to verify.
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Abstract
Patients with CKD exhibit a disproportionate burden of cardiovascular mortality, which likely stems from the presence of unique, nontraditional risk factors that accompany deteriorating kidney function. Mounting evidence suggests that alterations to the intestinal microbiome in CKD may serve as one such risk factor. The human intestinal tract is home to >100 trillion micro-organisms made up of a collection of commensal, symbiotic, and pathogenic species. These species along with their local environment constitute the intestinal microbiome. Patients with CKD show intestinal dysbiosis, an alteration of the gut micro-organism composition and function. Recent evidence links byproducts of intestinal dysbiosis to vascular calcification, atherosclerosis formation, and adverse cardiovascular outcomes in CKD. CKD-associated intestinal dysbiosis may also be accompanied by defects in intestinal barrier function, which could further enhance the negative effects of pathogenic intestinal bacteria in the human host. Thus, intestinal dysbiosis, defective intestinal barrier function, and a reduced capacity for clearance by the kidney of absorbed bacterial byproducts may all potentiate the development of cardiovascular disease in CKD. This narrative review focuses on microbiome-mediated mechanisms associated with CKD that may promote atherosclerosis formation and cardiovascular disease. It includes (1) new data supporting the hypothesis that intestinal barrier dysfunction leads to bacterial translocation and endotoxemia that potentiate systemic inflammation, (2) information on the accumulation of dietary-derived bacterial byproducts that stimulate pathways promoting atheromatous changes in arteries and cardiovascular disease, and (3) potential interventions. Despite great scientific interest in and a rapidly growing body of literature on the relationship between the microbiome and cardiovascular disease in CKD, many important questions remain unanswered.
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Affiliation(s)
- Anna Jovanovich
- Renal Section, Veterans Affairs Eastern Colorado Health Care System, Denver, Colorado
- Division of Renal Diseases and Hypertension, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Tamara Isakova
- Division of Nephrology and Hypertension, Department of Medicine and Center for Translational Metabolism and Health, Institute for Public Health and Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois; and
| | - Jason Stubbs
- The Jared Grantham Kidney Institute, Department of Medicine, University of Kansas Medical Center, Kansas City, Kansas
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Franco ÁDO, Starosta RT, Roriz-Cruz M. The specific impact of uremic toxins upon cognitive domains: a review. ACTA ACUST UNITED AC 2018; 41:103-111. [PMID: 30095142 PMCID: PMC6534037 DOI: 10.1590/2175-8239-jbn-2018-0033] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 05/14/2018] [Indexed: 12/13/2022]
Abstract
One of the mechanisms proposed for chronic kidney disease (CKD)-related cognitive impairment is the accumulation of uremic toxins due to the deterioration of the renal clearance function. Cognition can be categorized into five major domains according to its information processing functions: memory, attention, language, visual-spatial, and executive. We performed a review using the terms 'uric acid', 'indoxyl sulfate', 'p-cresyl sulfate', 'homocysteine', 'interleukins' and 'parathyroid hormone'. These are the compounds that were found to be strongly associated with cognitive impairment in CKD in the literature. The 26 selected articles point towards an association between higher levels of uric acid, homocysteine, and interleukin 6 with lower cognitive performance in executive, attentional, and memory domains. We also reviewed the hemodialysis effects on cognition. Hemodialysis seems to contribute to an amelioration of CKD-related encephalopathic dysfunction, although this improvement occurs more in some cognitive domains than in others.
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Affiliation(s)
| | - Rodrigo Tzovenos Starosta
- Universidade Federal do Rio Grande do Sul, Faculdade de Medicina, Porto Alegre, RS, Brasil.,Universidade Federal do Rio Grande do Sul, Programa de Pós-Graduação em Genética e Biologia Molecular, Porto Alegre, RS, Brasil
| | - Matheus Roriz-Cruz
- Universidade Federal do Rio Grande do Sul, Departamento de Medicina Interna, Porto Alegre, RS, Brasil.,Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brasil
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28
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Davenport A. Measuring residual renal function for hemodialysis adequacy: Is there an easier option? Hemodial Int 2018; 21 Suppl 2:S41-S46. [PMID: 29064172 DOI: 10.1111/hdi.12592] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 08/01/2017] [Indexed: 02/04/2023]
Abstract
Most patients starting hemodialysis (HD) have residual renal function. As such, there has been increased interest in starting patients with less frequent and shorter dialysis session times. However, for this incremental approach to be successful, patients require regular monitoring of residual renal function, so that as residual renal function declines, the amount of HD is appropriately increased. Currently most dialysis centers rely on interdialytic urine collections. However, many patients find these inconvenient and there may be marked intrapatient variability due to compliance issues. Thus, alternative markers of residual renal function are required for routine clinical practice. Currently three middle sized molecules; cystatin C, β2 microglobulin, and βtrace protein have been investigated as potential endogenous markers of glomerular filtration. Although none is ideal, combinations of these markers have been proposed to provide a more accurate estimation of glomerular clearance, and in particular cut offs for minimal residual renal function. However, in patients with low levels of residual renal function it remains unclear as to whether the benefits of residual renal function equally apply to glomerular filtration or tubular function.
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Affiliation(s)
- Andrew Davenport
- UCL Centre for Nephrology, Royal Free Hospital, University College London, Rowland Hill Street, London, NW3 2PF
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29
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Saum K, Campos B, Celdran-Bonafonte D, Nayak L, Sangwung P, Thakar C, Roy-Chaudhury P, Owens AP. Uremic Advanced Glycation End Products and Protein-Bound Solutes Induce Endothelial Dysfunction Through Suppression of Krüppel-Like Factor 2. J Am Heart Assoc 2018; 7:e007566. [PMID: 29301761 PMCID: PMC5778969 DOI: 10.1161/jaha.117.007566] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 11/22/2017] [Indexed: 01/01/2023]
Abstract
BACKGROUND Cardiovascular disease is the leading cause of morbidity and mortality in patients with end-stage renal disease. The accumulation of uremic solutes in this patient population is associated with endothelial dysfunction and accelerated cardiovascular disease. In this study, we examined the impact of the uremic milieu on the endothelial transcription factor, Krüppel-like factor 2 (KLF2), a key regulator of endothelial function and activation. METHODS AND RESULTS Using serum from uremic pigs with chronic renal insufficiency, our results show that KLF2 expression is suppressed by the uremic milieu and individual uremic solutes in vitro. Specifically, KLF2 expression is significantly decreased in human umbilical vein endothelial cells after treatment with uremic porcine serum or carboxymethyllysine-modified albumin, an advanced glycation end product (AGE) known to induce endothelial dysfunction. AGE-mediated suppression of KLF2 is dependent on activation of the receptor for AGE, as measured by small interfering RNA knockdown of the receptor for AGE. Furthermore, KLF2 suppression promotes endothelial dysfunction, because adenoviral overexpression of KLF2 inhibits reactive oxygen species production and leukocyte adhesion in human umbilical vein endothelial cells. In addition, the application of hemodynamic shear stress, prolonged serum dialysis, or treatment with the receptor for AGE antagonist azeliragon (TTP488) is sufficient to prevent KLF2 suppression in vitro. To decipher the mechanism by which uremic AGEs suppress KLF2 expression, we assessed the role of the receptor for AGE in activation of nuclear factor-κB signaling, a hallmark of endothelial cell activation. Using a constitutively active form of IκBα, we show that translocation of p65 to the nucleus is necessary for KLF2 suppression after treatment with uremic AGEs. CONCLUSIONS These data identify KLF2 suppression as a consequence of the uremic milieu, which may exacerbate endothelial dysfunction and resultant cardiovascular disease.
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Affiliation(s)
- Keith Saum
- University of Cincinnati Medical Scientist Training Program, The University of Cincinnati College of Medicine, Cincinnati, OH
- Division of Nephrology and Hypertension, The University of Cincinnati College of Medicine, Cincinnati, OH
| | - Begoña Campos
- Division of Nephrology and Hypertension, The University of Cincinnati College of Medicine, Cincinnati, OH
| | - Diego Celdran-Bonafonte
- Division of Nephrology, University of Arizona College of Medicine and Banner University Medical Centers-Tucson and South and Southern Arizona Veterans Affairs Healthcare System, Tucson, AZ
| | - Lalitha Nayak
- Division of Hematology and Oncology, University Hospitals Cleveland Medical Center, Case Western Reserve University School of Medicine, Cleveland, OH
| | - Panjamaporn Sangwung
- Department of Physiology and Biophysics, Department of Medicine, Cardiovascular Research Institute, Case Western Reserve University School of Medicine, Cleveland, OH
| | - Charuhas Thakar
- Division of Nephrology and Hypertension, The University of Cincinnati College of Medicine, Cincinnati, OH
| | - Prabir Roy-Chaudhury
- Division of Nephrology and Hypertension, The University of Cincinnati College of Medicine, Cincinnati, OH
- Division of Nephrology, University of Arizona College of Medicine and Banner University Medical Centers-Tucson and South and Southern Arizona Veterans Affairs Healthcare System, Tucson, AZ
| | - A Phillip Owens
- Division of Cardiovascular Health and Disease, The University of Cincinnati College of Medicine, Cincinnati, OH
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30
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Shafi T, Levey AS. Measurement and Estimation of Residual Kidney Function in Patients on Dialysis. Adv Chronic Kidney Dis 2018; 25:93-104. [PMID: 29499893 PMCID: PMC5841591 DOI: 10.1053/j.ackd.2017.09.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 09/11/2017] [Indexed: 12/17/2022]
Abstract
Residual kidney function (RKF) in patients on dialysis is strongly associated with survival and better quality of life. Assessment of kidney function underlies the management of patients with chronic kidney disease before dialysis initiation. However, methods to assess RKF after dialysis initiation are just now being refined. In this review, we discuss the definition of RKF and methods for measurement and estimation of RKF, highlighting the unique aspects of dialysis that impact these assessments.
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Affiliation(s)
- Tariq Shafi
- Division of Nephrology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD; Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins University, Baltimore, MD; Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD; and Division of Nephrology, Department of Medicine, Tufts Medical Center, Boston, MA.
| | - Andrew S Levey
- Division of Nephrology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD; Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins University, Baltimore, MD; Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD; and Division of Nephrology, Department of Medicine, Tufts Medical Center, Boston, MA
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31
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Guida B, Cataldi M, Memoli A, Trio R, di Maro M, Grumetto L, Capuano I, Federico S, Pisani A, Sabbatini M. Effect of a Short-Course Treatment with Synbiotics on Plasma p-Cresol Concentration in Kidney Transplant Recipients. J Am Coll Nutr 2017; 36:586-591. [PMID: 28895794 DOI: 10.1080/07315724.2017.1334602] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVE We evaluated whether a short-term course with synbiotics may lower plasma p-Cresol concentrations in kidney transplant patients (KTRs) who accumulate this uremic toxin both because of increased production by their dysbiotic gut microbiome and because of reduced elimination by the transplanted kidneys. METHODS Thirty-six KTRs (29 males, mean age 49.6 ± 9.1 years) with transplant vintage > 12 months, stable graft function, and no episode of acute rejection or infection in the last 3 months were enrolled in this single-center, parallel-group, double-blinded, randomized (2:1 synbiotic to placebo) study. Synbiotic (Probinul Neutro, CadiGroup, Rome, Italy) or placebo was taken at home for 30 days, as 5 g powder packets dissolved in water three times a day far from meals. The main outcome measure was the decrease in total plasma p-Cresol measured by high-performance liquid chromatography at baseline and after 15 and 30 days of placebo or synbiotic treatment. RESULTS After 15 and 30 days of treatment, plasma p-Cresol decreased by 40% and 33% from baseline (both p < 0.05), respectively, in the synbiotic group, whereas it remained stable in the placebo group. After 30 days of treatment, no significant change was observed in either group in renal function, glycemia, plasma lipids, or albumin concentration. Treatment was well tolerated and did not induce any change in stool characteristics. CONCLUSION The results of this pilot study suggest that treatment with synbiotics may be effective to lower plasma p-Cresol concentrations in KTRs. Prospective larger scale, longer term studies are needed to establish whether cardiovascular prognosis could also be improved with this nutritional intervention.
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Affiliation(s)
- Bruna Guida
- a Department of Clinical Medicine and Surgery, Physiology Nutrition Unit , Federico II University of Naples , Naples , Italy.,b Federico II University Hospital , Naples , Italy
| | - Mauro Cataldi
- b Federico II University Hospital , Naples , Italy.,c Department of Neuroscience, Reproductive Sciences and Dentistry, Division of Pharmacology , Federico II University of Naples , Naples , Italy
| | - Andrea Memoli
- b Federico II University Hospital , Naples , Italy.,d Department of Public Health, Nephrology Section , Federico II University of Naples , Naples , Italy
| | | | - Martina di Maro
- a Department of Clinical Medicine and Surgery, Physiology Nutrition Unit , Federico II University of Naples , Naples , Italy.,b Federico II University Hospital , Naples , Italy
| | - Lucia Grumetto
- e Department of Pharmaceutical and Toxicological Chemistry , Federico II University of Naples , Naples , Italy
| | - Ivana Capuano
- b Federico II University Hospital , Naples , Italy.,d Department of Public Health, Nephrology Section , Federico II University of Naples , Naples , Italy
| | - Stefano Federico
- b Federico II University Hospital , Naples , Italy.,d Department of Public Health, Nephrology Section , Federico II University of Naples , Naples , Italy
| | - Antonio Pisani
- b Federico II University Hospital , Naples , Italy.,d Department of Public Health, Nephrology Section , Federico II University of Naples , Naples , Italy
| | - Massimo Sabbatini
- b Federico II University Hospital , Naples , Italy.,d Department of Public Health, Nephrology Section , Federico II University of Naples , Naples , Italy
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32
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Maheshwari V, Thijssen S, Tao X, Fuertinger D, Kappel F, Kotanko P. A novel mathematical model of protein-bound uremic toxin kinetics during hemodialysis. Sci Rep 2017; 7:10371. [PMID: 28871178 PMCID: PMC5583320 DOI: 10.1038/s41598-017-10981-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 08/10/2017] [Indexed: 11/17/2022] Open
Abstract
Protein-bound uremic toxins (PBUTs) are difficult to remove by conventional hemodialysis; a high degree of protein binding reduces the free fraction of toxins and decreases their diffusion across dialyzer membranes. Mechanistic understanding of PBUT kinetics can open new avenues to improve their dialytic removal. We developed a comprehensive model of PBUT kinetics that comprises: (1) a three-compartment patient model, (2) a dialyzer model. The model accounts for dynamic equilibrium between protein, toxin, and the protein-toxin complex. Calibrated and validated using clinical and experimental data from the literature, the model predicts key aspects of PBUT kinetics, including the free and bound concentration profiles for PBUTs and the effects of dialysate flow rate and dialyzer size on PBUT removal. Model simulations suggest that an increase in dialysate flow rate improves the reduction ratio (and removal) of strongly protein-bound toxins, namely, indoxyl sulfate and p-cresyl sulfate, while for weakly bound toxins, namely, indole-3-acetic acid and p-cresyl glucuronide, an increase in blood flow rate is advantageous. With improved dialyzer performance, removal of strongly bound PBUTs improves gradually, but marginally. The proposed model can be used for optimizing the dialysis regimen and for in silico testing of novel approaches to enhance removal of PBUTs.
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Affiliation(s)
| | | | - Xia Tao
- Renal Research Institute, New York, USA
| | | | - Franz Kappel
- Institute for Mathematics and Scientific Computing, University of Graz, Graz, Austria
| | - Peter Kotanko
- Renal Research Institute, New York, USA.,Icahn School of Medicine at Mount Sinai, New York, USA
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Tangvoraphonkchai K, Davenport A. Increasing Haemodialytic Clearances as Residual Renal Function Declines: An Incremental Approach. Blood Purif 2017; 44:217-226. [DOI: 10.1159/000475458] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 04/02/2017] [Indexed: 11/19/2022]
Abstract
Many patients with chronic kidney disease start undergoing thrice-weekly haemodialysis (HD), aiming for an HD sessional dialyzer urea clearance target, irrespective of whether they have residual renal function (RRF). While increasing sessional dialyzer urea clearance above a target of 1.2 has not been shown to improve patient survival, it has been shown that the preservation of RRF improves patient self-reported outcomes and survival. Observational studies have suggested that initiating twice-weekly HD schedules leads to greater preservation of RRF. This has led to the concept of following an incremental approach to initiating HD, steadily increasing the amount of weekly dialyzer clearance as RRF decreases. Incremental dialysis practice requires the regular assessment of RRF to prevent inadequate delivery of dialysis treatment. Once RRF is lost, then the dialysis schedule and modality need to be adjusted to try to increase the middle-sized solute clearance and protein-bound toxins.
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34
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Deltombe O, de Loor H, Glorieux G, Dhondt A, Van Biesen W, Meijers B, Eloot S. Exploring binding characteristics and the related competition of different protein-bound uremic toxins. Biochimie 2017; 139:20-26. [DOI: 10.1016/j.biochi.2017.05.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 05/16/2017] [Indexed: 11/25/2022]
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35
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Disposition and clinical implications of protein-bound uremic toxins. Clin Sci (Lond) 2017; 131:1631-1647. [DOI: 10.1042/cs20160191] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 04/10/2017] [Accepted: 04/11/2017] [Indexed: 12/11/2022]
Abstract
In patients with chronic kidney disease (CKD), adequate renal clearance is compromised, resulting in the accumulation of a plethora of uremic solutes. These uremic retention solutes, also named uremic toxins, are a heterogeneous group of organic compounds with intrinsic biological activities, many of which are too large to be filtered and/or are protein bound. The renal excretion of protein-bound toxins depends largely on active tubular secretion, which shifts the binding and allows for active secretion of the free fraction. To facilitate this process, renal proximal tubule cells are equipped with a range of transporters that co-operate in basolateral uptake and luminal excretion. Many of these transporters have been characterized as mediators of drug disposition, but have recently been recognized for their importance in the proximal renal tubular transport of uremic toxins as well. This also indicates that during uremia, drug disposition may be severely affected as a result of drug–uremic toxin interaction. In addition, CKD patients receive various drugs to treat their complications potentially resulting in drug–drug interactions (DDIs), also for drugs that are non-renally excreted. This review discusses the current knowledge on formation, disposition and removal of protein-bound uremic toxins. Furthermore, implications associated with drug treatment in kidney failure, as well as innovative renal replacement therapies targetting the protein-bound uremic toxins are being discussed. It will become clear that the complex problems associated with uremia warrant a transdisciplinary approach that unites research experts in the area of fundamental biomedical research with their colleagues in clinical nephrology.
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36
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Sandeman SR, Zheng Y, Ingavle GC, Howell CA, Mikhalovsky SV, Basnayake K, Boyd O, Davenport A, Beaton N, Davies N. A haemocompatible and scalable nanoporous adsorbent monolith synthesised using a novel lignin binder route to augment the adsorption of poorly removed uraemic toxins in haemodialysis. Biomed Mater 2017; 12:035001. [DOI: 10.1088/1748-605x/aa6546] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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37
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Tangvoraphonkchai K, Davenport A. Incremental Hemodialysis - A European Perspective. Semin Dial 2017; 30:270-276. [PMID: 28185299 DOI: 10.1111/sdi.12583] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Most patients initiating hemodialysis have residual renal function (RRF). Whereas RRF is monitored prior to commencing hemodialysis, once dialysis is started most centres simply rely on dialyzer urea clearance to determine adequate uremic toxin clearance and disregard the effect of RRF. However sustaining RRF is important for the dialysis patient, as RRF reduces inter-dialytic weight gains, increases middle molecule and protein bound toxin clearances and is associated with better quality of life assessments. Paradoxically, more frequent dialysis and longer dialysis sessions appear to be associated with more rapid loss of RRF. As such, starting patients with less frequent or shorter dialysis sessions, depending upon individual patient comorbidity, may lead to better preservation of RRF. However to prevent inadequate uremic toxin clearance or volume overload, RRF needs to be regularly monitored. Unfortunately, the 24-hour urine collection for urea and creatinine clearance remains the mainstay for RRF assessment. This measurement chiefly represents glomerular clearance rather than tubular function, but the latter may be also important for the dialysis patients. Incremental dialysis with less initial dialysis treatment may lower costs and will allow others to dialyze more frequently. The key to start a successful incremental hemodialysis approach is the regular monitoring of the patient, so that as RRF is lost an appropriate decision can be made regarding increasing dialysis session duration and frequency on an individual patient basis or consider switching modalities to hemodiafiltration.
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Affiliation(s)
| | - Andrew Davenport
- UCL Centre for Nephrology, Royal Free Hospital, University College London Medical School, London, United Kingdom
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38
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p-Cresyl sulfate is associated with carotid arteriosclerosis in hemodialysis patients and promotes atherogenesis in apoE-/- mice. Kidney Int 2017; 89:439-49. [PMID: 26466319 DOI: 10.1038/ki.2015.287] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 07/06/2015] [Accepted: 07/24/2015] [Indexed: 01/22/2023]
Abstract
p-Cresyl sulfate (PCS) is a risk factor of cardiovascular disease in patients with chronic kidney disease. Here we tested whether serum PCS levels were related to the rate and evolution of carotid atherosclerosis in hemodialysis patients and identified a potential mechanism. A total of 200 hemodialysis patients were categorized as with or without carotid atherosclerotic plaque and followed for 5 years. Serum PCS levels were found to be higher in patients with than without carotid atherosclerotic plaque and positively correlated with increased total plaque area during follow-up. Multiple logistic regression and mixed effects model analyses showed that serum PCS levels were independently associated with the incidence and progression of carotid atherosclerotic plaque. PCS induced inflammatory factor and adhesion molecule expression in endothelial cells and macrophages. In addition, PCS triggered monocyte-endothelial cell interaction in vitro and in vivo through increased production of reactive oxygen species. Compared with controls, increase of PCS levels produced by gavage promoted atherogenesis in 5/6-nephrectomized apoE-/- mice; a process attenuated by NADPH oxidase inhibitors. Thus, increased serum PCS levels are associated with the occurrence and progression of carotid atherosclerosis in hemodialysis patients and promote atherogenesis through increased reactive oxygen species production.
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39
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Han H, Chen Y, Zhu Z, Su X, Ni J, Du R, Zhang R, Jin W. p-Cresyl sulfate promotes the formation of atherosclerotic lesions and induces plaque instability by targeting vascular smooth muscle cells. Front Med 2016; 10:320-9. [PMID: 27527366 DOI: 10.1007/s11684-016-0463-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 06/12/2016] [Indexed: 12/17/2022]
Abstract
Coronary atherosclerosis is a major complication of chronic kidney disease. This condition contributes to the increased mortality in dialysis patients. p-Cresyl sulfate (PCS) is a prototype of protein-bound uremic toxins that cannot be efficiently removed through routine dialysis procedures. In the present study, ApoE(-/-) mice that underwent 5/6 nephrectomy were randomly divided into two groups, namely, vehicle-treated group (n = 20) and PCS-treated group (n = 20). Mice were sacrificed for en face and immunohistological analyses after 8 or 24 weeks of high-fat diet. Rat aortic vascular smooth muscle cells (VSMCs) were treated with phosphate buffer solution or 500 μmol/L PCS for in vitro evaluation. PCS-treated mice were observed to suffer increased atherosclerotic lesions after eight weeks of PCS administration. Moreover, 24 weeks of PCS administration also markedly increased the vulnerability index of aortic plaques. PCS was also observed to facilitate the migration and proliferation of VSMCs during the progression of the disease. Moreover, PCS disturbed the balance between matrix metalloproteinases and tissue inhibitor of metalloproteinases within the plaques. Thus, PCS played a vital role in promoting atherogenesis and disturbing the stability of formed plaques probably by targeting VSMCs.
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Affiliation(s)
- Hui Han
- Department of Cardiology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.,Institute of Cardiovascular Diseases, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Yanjia Chen
- Department of Cardiology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.,Institute of Cardiovascular Diseases, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Zhengbin Zhu
- Department of Cardiology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Xiuxiu Su
- Department of Cardiology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Jingwei Ni
- Department of Cardiology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Run Du
- Department of Cardiology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Ruiyan Zhang
- Department of Cardiology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China. .,Institute of Cardiovascular Diseases, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
| | - Wei Jin
- Department of Cardiology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
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Poesen R, Evenepoel P, de Loor H, Kuypers D, Augustijns P, Meijers B. Metabolism, Protein Binding, and Renal Clearance of Microbiota-Derived p-Cresol in Patients with CKD. Clin J Am Soc Nephrol 2016; 11:1136-1144. [PMID: 27084876 PMCID: PMC4934829 DOI: 10.2215/cjn.00160116] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 03/25/2016] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Colonic microbial metabolism substantially contributes to uremic retention solutes in CKD. p-Cresyl sulfate is the main representative of this group of solutes, relating to adverse outcomes. Other than sulfate conjugation, p-cresol is subjected to endogenous glucuronide conjugation. Whether the balance between sulfate and glucuronide conjugation is relevant in CKD is unexplored. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We prospectively followed 488 patients with CKD stages 1-5 (enrollment between November of 2005 and September of 2006; follow-up until December of 2010). Serum and urine levels of p-cresyl sulfate and p-cresyl glucuronide were measured using liquid chromatography-mass spectrometry. Total amount of microbial p-cresol was calculated by the sum of serum p-cresyl sulfate and p-cresyl glucuronide. Outcome analysis was performed for mortality and cardiovascular disease. RESULTS Serum p-cresyl sulfate was a median of 193.0-fold (interquartile range, 121.1-296.6) higher than serum p-cresyl glucuronide, with a significant correlation between eGFR and proportion of serum p-cresyl sulfate to glucuronide (rho=0.23; P=0.001). There was also a significant correlation between eGFR and proportion of 24-hour urinary excretion of p-cresyl sulfate to glucuronide (rho=0.32; P<0.001). Higher serum p-cresol and lower proportion of serum p-cresyl sulfate to glucuronide were jointly and significantly associated with mortality (hazard ratio per SD higher, 1.58; 95% confidence interval, 1.10 to 2.29; P=0.01 and hazard ratio, 0.65; 95% confidence interval, 0.47 to 0.89; P<0.01, respectively) and cardiovascular disease (hazard ratio, 1.68; 95% confidence interval, 1.27 to 2.22; P<0.001 and hazard ratio, 0.55; 95% confidence interval, 0.42 to 0.72; P<0.001, respectively) after adjustment for eGFR, Framingham risk factors, mineral bone metabolism markers, C-reactive protein, and albumin. CONCLUSIONS p-Cresol shows a preponderance of sulfate conjugation, although a relatively diminished sulfotransferase activity can be suggested in patients with advanced CKD. Along with total p-cresol burden, a relative shift from sulfate to glucuronide conjugation is independently associated with mortality and cardiovascular disease, warranting increased focus to the dynamic interplay between microbial and endogenous metabolism.
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Affiliation(s)
- Ruben Poesen
- Department of Microbiology and Immunology, Division of Nephrology, University Hospitals Leuven, Leuven, Belgium; and
| | - Pieter Evenepoel
- Department of Microbiology and Immunology, Division of Nephrology, University Hospitals Leuven, Leuven, Belgium; and
| | - Henriette de Loor
- Department of Microbiology and Immunology, Division of Nephrology, University Hospitals Leuven, Leuven, Belgium; and
| | - Dirk Kuypers
- Department of Microbiology and Immunology, Division of Nephrology, University Hospitals Leuven, Leuven, Belgium; and
| | - Patrick Augustijns
- Department of Pharmaceutical and Pharmacological Sciences, Drug Delivery and Disposition, University of Leuven, Leuven, Belgium
| | - Björn Meijers
- Department of Microbiology and Immunology, Division of Nephrology, University Hospitals Leuven, Leuven, Belgium; and
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Bioengineered kidney tubules efficiently excrete uremic toxins. Sci Rep 2016; 6:26715. [PMID: 27242131 PMCID: PMC4886219 DOI: 10.1038/srep26715] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 05/09/2016] [Indexed: 12/12/2022] Open
Abstract
The development of a biotechnological platform for the removal of waste products (e.g. uremic toxins), often bound to proteins in plasma, is a prerequisite to improve current treatment modalities for patients suffering from end stage renal disease (ESRD). Here, we present a newly designed bioengineered renal tubule capable of active uremic toxin secretion through the concerted action of essential renal transporters, viz. organic anion transporter-1 (OAT1), breast cancer resistance protein (BCRP) and multidrug resistance protein-4 (MRP4). Three-dimensional cell monolayer formation of human conditionally immortalized proximal tubule epithelial cells (ciPTEC) on biofunctionalized hollow fibers with maintained barrier function was demonstrated. Using a tailor made flow system, the secretory clearance of human serum albumin-bound uremic toxins, indoxyl sulfate and kynurenic acid, as well as albumin reabsorption across the renal tubule was confirmed. These functional bioengineered renal tubules are promising entities in renal replacement therapies and regenerative medicine, as well as in drug development programs.
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Poesen R, Claes K, Evenepoel P, de Loor H, Augustijns P, Kuypers D, Meijers B. Microbiota-Derived Phenylacetylglutamine Associates with Overall Mortality and Cardiovascular Disease in Patients with CKD. J Am Soc Nephrol 2016; 27:3479-3487. [PMID: 27230658 DOI: 10.1681/asn.2015121302] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 02/21/2016] [Indexed: 11/03/2022] Open
Abstract
Colonic microbial metabolism substantially contributes to uremic solute production. p-Cresyl sulfate and indoxyl sulfate are the main representatives of solutes of microbial origin and also, protein-bound solutes, exhibiting high protein-binding affinity and dependence on tubular secretion. Phenylacetylglutamine is another microbial metabolite with high dependence on tubular secretion but low protein-binding affinity. The relevance of such solutes is unknown. Therefore, we prospectively followed 488 patients with CKD stages 1-5 and a measurement of serum phenylacetylglutamine by liquid chromatography-mass spectrometry. In a subgroup, we determined 24-hour urinary excretion as a surrogate of intestinal uptake as well as renal clearance of phenylacetylglutamine. We performed outcome analysis for mortality (51 events) and cardiovascular disease (75 events). Serum phenylacetylglutamine level correlated with 24-hour urinary excretion (rho=0.55; P<0.001) and clearance of phenylacetylglutamine (rho=-0.76; P<0.001). Phenylacetylglutamine clearance also correlated with eGFR (rho=0.84; P<0.001). Furthermore, serum phenylacetylglutamine level associated with mortality (hazard ratio per 1-SD increase, 1.77; 95% confidence interval, 1.22 to 2.57; P=0.003) and cardiovascular disease (hazard ratio, 1.79; 95% confidence interval, 1.32 to 2.41; P<0.001) after adjustment for age, sex, presence of diabetes mellitus, prior cardiovascular disease, and eGFR. Thus, serum phenylacetylglutamine level is elevated in patients with more advanced CKD and determined by intestinal uptake and renal clearance, and it is not fully accounted for by differences in eGFR. High serum phenylacetylglutamine level is a strong and independent risk factor for mortality and cardiovascular disease, suggesting the relevance of microbial metabolism and/or tubular dysfunction in CKD, irrespective of protein binding.
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Affiliation(s)
- Ruben Poesen
- Department of Microbiology and Immunology, Division of Nephrology, University Hospitals Leuven, Leuven, Belgium; and
| | - Kathleen Claes
- Department of Microbiology and Immunology, Division of Nephrology, University Hospitals Leuven, Leuven, Belgium; and
| | - Pieter Evenepoel
- Department of Microbiology and Immunology, Division of Nephrology, University Hospitals Leuven, Leuven, Belgium; and
| | - Henriette de Loor
- Department of Microbiology and Immunology, Division of Nephrology, University Hospitals Leuven, Leuven, Belgium; and
| | - Patrick Augustijns
- Department of Pharmaceutical and Pharmacological Sciences, Drug Delivery and Disposition, University of Leuven, Leuven, Belgium
| | - Dirk Kuypers
- Department of Microbiology and Immunology, Division of Nephrology, University Hospitals Leuven, Leuven, Belgium; and
| | - Björn Meijers
- Department of Microbiology and Immunology, Division of Nephrology, University Hospitals Leuven, Leuven, Belgium; and
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Exploring Protein Binding of Uremic Toxins in Patients with Different Stages of Chronic Kidney Disease and during Hemodialysis. Toxins (Basel) 2015; 7:3933-46. [PMID: 26426048 PMCID: PMC4626712 DOI: 10.3390/toxins7103933] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 09/16/2015] [Accepted: 09/22/2015] [Indexed: 12/12/2022] Open
Abstract
As protein binding of uremic toxins is not well understood, neither in chronic kidney disease (CKD) progression, nor during a hemodialysis (HD) session, we studied protein binding in two cross-sectional studies. Ninety-five CKD 2 to 5 patients and ten stable hemodialysis patients were included. Blood samples were taken either during the routine ambulatory visit (CKD patients) or from blood inlet and outlet line during dialysis (HD patients). Total (CT) and free concentrations were determined of p-cresylglucuronide (pCG), hippuric acid (HA), indole-3-acetic acid (IAA), indoxyl sulfate (IS) and p-cresylsulfate (pCS), and their percentage protein binding (%PB) was calculated. In CKD patients, %PB/CT resulted in a positive correlation (all p < 0.001) with renal function for all five uremic toxins. In HD patients, %PB was increased after 120 min of dialysis for HA and at the dialysis end for the stronger (IAA) and the highly-bound (IS and pCS) solutes. During one passage through the dialyzer at 120 min, %PB was increased for HA (borderline), IAA, IS and pCS. These findings explain why protein-bound solutes are difficult to remove by dialysis: a combination of the fact that (i) only the free fraction can pass the filter and (ii) the equilibrium, as it was pre-dialysis, cannot be restored during the dialysis session, as it is continuously disturbed.
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Glorieux G, Tattersall J. Uraemic toxins and new methods to control their accumulation: game changers for the concept of dialysis adequacy. Clin Kidney J 2015; 8:353-62. [PMID: 26251699 PMCID: PMC4515890 DOI: 10.1093/ckj/sfv034] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Revised: 04/21/2015] [Accepted: 04/22/2015] [Indexed: 02/07/2023] Open
Abstract
The current concept of an adequate dialysis based only on the dialysis process itself is rather limited. We now have considerable knowledge of uraemic toxicity and improved tools for limiting uraemic toxin accumulation. It is time to make use of these. A broader concept of adequacy that focusses on uraemic toxicity is required. As discussed in the present review, adequacy could be achieved by many different methods in combination with, or instead of, dialysis. These include preservation of renal function, dietary intake, reducing uraemic toxin generation rate and intestinal absorption, isolated ultrafiltration and extracorporeal adsorption of key uraemic toxins. A better measure of the quality of dialysis treatment would quantify the uraemic state in the patient using levels of a panel of key uraemic toxins. Treatment would focus on controlling uraemic toxicity while reducing harm or inconvenience to the patient. Delivering more dialysis might not be the best way to achieve this.
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Affiliation(s)
- Griet Glorieux
- Department of Internal Medicine, Nephrology Division , Ghent University Hospital , Gent , Belgium
| | - James Tattersall
- Department of Renal Medicine , Leeds Teaching Hospitals , Leeds LS2 7EF , UK
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Carding S, Verbeke K, Vipond DT, Corfe BM, Owen LJ. Dysbiosis of the gut microbiota in disease. MICROBIAL ECOLOGY IN HEALTH AND DISEASE 2015; 26:26191. [PMID: 25651997 PMCID: PMC4315779 DOI: 10.3402/mehd.v26.26191] [Citation(s) in RCA: 714] [Impact Index Per Article: 79.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
There is growing evidence that dysbiosis of the gut microbiota is associated with the pathogenesis of both intestinal and extra-intestinal disorders. Intestinal disorders include inflammatory bowel disease, irritable bowel syndrome (IBS), and coeliac disease, while extra-intestinal disorders include allergy, asthma, metabolic syndrome, cardiovascular disease, and obesity. In many of these conditions, the mechanisms leading to disease development involves the pivotal mutualistic relationship between the colonic microbiota, their metabolic products, and the host immune system. The establishment of a ‘healthy’ relationship early in life appears to be critical to maintaining intestinal homeostasis. Whilst we do not yet have a clear understanding of what constitutes a ‘healthy’ colonic microbiota, a picture is emerging from many recent studies identifying particular bacterial species associated with a healthy microbiota. In particular, the bacterial species residing within the mucus layer of the colon, either through direct contact with host cells, or through indirect communication via bacterial metabolites, may influence whether host cellular homeostasis is maintained or whether inflammatory mechanisms are triggered. In addition to inflammation, there is some evidence that perturbations in the gut microbiota is involved with the development of colorectal cancer. In this case, dysbiosis may not be the most important factor, rather the products of interaction between diet and the microbiome. High-protein diets are thought to result in the production of carcinogenic metabolites from the colonic microbiota that may result in the induction of neoplasia in the colonic epithelium. Ever more sensitive metabolomics methodologies reveal a suite of small molecules produced in the microbiome which mimic or act as neurosignallers or neurotransmitters. Coupled with evidence that probiotic interventions may alter psychological endpoints in both humans and in rodent models, these data suggest that CNS-related co-morbidities frequently associated with GI disease may originate in the intestine as a result of microbial dysbiosis. This review outlines the current evidence showing the extent to which the gut microbiota contributes to the development of disease. Based on evidence to date, we can assess the potential to positively modulate the composition of the colonic microbiota and ameliorate disease activity through bacterial intervention.
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Affiliation(s)
- Simon Carding
- Institute of Food Research, Norwich, UK.,Norwich Medical School, University of East Anglia, Norwich, UK
| | - Kristin Verbeke
- Translational Research in GastroIntestinal Disorders, KU Leuven, Leuven, Belgium
| | - Daniel T Vipond
- Institute of Food Research, Norwich, UK.,Norwich Medical School, University of East Anglia, Norwich, UK
| | - Bernard M Corfe
- Molecular Gastroenterology Research Group, Department of Oncology, University of Sheffield, Sheffield, UK.,Insigneo Institute for in silico Medicine, University of Sheffield, Sheffield, UK;
| | - Lauren J Owen
- Human Nutrition Unit, Department of Oncology, University of Sheffield, Sheffield, UK
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Abstract
The development of dialysis was a dramatic step forward in medicine, allowing people who would soon have died because of lack of kidney function to remain alive for years. We have since found, however, that the "artificial kidney" does not live up fully to its name. Dialysis keeps patients alive but not well. Part of the residual illness that dialysis patients experience is caused by retained waste solutes that dialysis does not remove as well as native kidney function does. New means are available to identify these toxic solutes, about which we currently know remarkably little, and knowledge of these solutes would help us to improve therapy. This review summarizes our current knowledge of toxic solutes and highlights methods being explored to identify additional toxic solutes and to enhance the clearance of these solutes to improve patient outcomes.
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Affiliation(s)
- Timothy W Meyer
- Department of Medicine, Veterans Affairs Palo Alto Healthcare System, Palo Alto, California; Department of Medicine, Stanford University, Palo Alto, California; and
| | - Thomas H Hostetter
- Department of Medicine, Case Western Reserve University, Cleveland, Ohio
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48
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Nonextracorporeal Methods for Decreasing Uremic Solute Concentration: A Future Way To Go? Semin Nephrol 2014; 34:228-43. [DOI: 10.1016/j.semnephrol.2014.02.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Mullen W, Saigusa D, Abe T, Adamski J, Mischak H. Proteomics and Metabolomics as Tools to Unravel Novel Culprits and Mechanisms of Uremic Toxicity: Instrument or Hype? Semin Nephrol 2014; 34:180-90. [DOI: 10.1016/j.semnephrol.2014.02.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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50
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Eloot S, Ledebo I, Ward RA. Extracorporeal Removal of Uremic Toxins: Can We Still Do Better? Semin Nephrol 2014; 34:209-27. [DOI: 10.1016/j.semnephrol.2014.02.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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