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Wang L, Xu A, Wang J, Fan G, Liu R, Wei L, Pei M. The effect and mechanism of Fushen Granule on gut microbiome in the prevention and treatment of chronic renal failure. Front Cell Infect Microbiol 2024; 13:1334213. [PMID: 38274729 PMCID: PMC10808756 DOI: 10.3389/fcimb.2023.1334213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 12/14/2023] [Indexed: 01/27/2024] Open
Abstract
Background Fushen Granule is an improved granule based on the classic formula Fushen Formula, which is used for the treatment of peritoneal dialysis-related intestinal dysfunction in patients with end-stage renal disease. However, the effect and mechanism of this granule on the prevention and treatment of chronic renal failure have not been fully elucidated. Methods A 5/6 nephrectomy model of CRF was induced and Fushen Granule was administered at low and high doses to observe its effects on renal function, D-lactate, serum endotoxin, and intestinal-derived metabolic toxins. The 16SrRNA sequencing method was used to analyze the abundance and structure of the intestinal flora of CRF rats. A FMT assay was also used to evaluate the effects of transplantation of Fushen Granule fecal bacteria on renal-related functional parameters and metabolic toxins in CRF rats. Results Gavage administration of Fushen Granule at low and high doses down-regulated creatinine, urea nitrogen, 24-h urine microalbumin, D-lactate, endotoxin, and the intestinal-derived toxins indophenol sulphateand p-cresol sulphate in CRF rats. Compared with the sham-operated group in the same period, CRF rats had a decreased abundance of the firmicutes phylum and an increased abundance of the bacteroidetes phylum at the phylum level, and a decreasing trend of the lactobacillus genus at the genus level. Fushen Granule intervention increased the abundance of the firmicutes phylum, decreased the abundance of the bacteroidetes phylum, and increased the abundance of the lactobacillus genus. The transplantation of Fushen Granule fecal bacteria significantly reduced creatinine(Cr), blood urea nitrogen(Bun), uric acid(UA), 24-h urinary microalbumin, D-lactate, serum endotoxin, and enterogenic metabolic toxins in CRF rats. Compared with the sham-operated group, the transplantation of Fushen Granule fecal bacteria modulated the Firmicutes and Bacteroidetes phyla and the Lactobacillus genus. Conclusion Fushen Granule improved renal function and intestinal barrier function by regulating intestinal flora, inhibiting renal fibrosis, and delaying the progression of chronic renal failure.
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Affiliation(s)
- Lin Wang
- Nephrology Department, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
- Graduate School, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Ao Xu
- Nephrology Department, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
- Graduate School, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Jinxiang Wang
- Guangdong Provincial Key Laboratory of Digestive Cancer Research, Precision Medicine Center, Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, China
| | - Guorong Fan
- Nephrology Department, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
- Graduate School, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Ruiqi Liu
- Nephrology Department, Tianjin Academy of Traditional Chinese Medicine Affiliated Hospital, Tianjin, China
| | - Lijuan Wei
- Nephrology Department, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
- Graduate School, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Ming Pei
- Nephrology Department, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
- Graduate School, Tianjin University of Traditional Chinese Medicine, Tianjin, China
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Day F, O’Sullivan J, Pook C. 4-Ethylphenol-fluxes, metabolism and excretion of a gut microbiome derived neuromodulator implicated in autism. Front Mol Biosci 2023; 10:1267754. [PMID: 37900921 PMCID: PMC10602680 DOI: 10.3389/fmolb.2023.1267754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 09/26/2023] [Indexed: 10/31/2023] Open
Abstract
Gut-microbiome-derived metabolites, such as 4-Ethylphenol [4EP], have been shown to modulate neurological health and function. Although the source of such metabolites is becoming better understood, knowledge gaps remain as to the mechanisms by which they enter host circulation, how they are transported in the body, how they are metabolised and excreted, and the way they exert their effects. High blood concentrations of host-modified 4EP, 4-ethylphenol sulfate [4EPS], are associated with an anxiety phenotype in autistic individuals. We have reviewed the existing literature and discuss mechanisms that are proposed to contribute influx from the gut microbiome, metabolism, and excretion of 4EP. We note that increased intestinal permeability is common in autistic individuals, potentially explaining increased flux of 4EP and/or 4EPS across the gut epithelium and the Blood Brain Barrier [BBB]. Similarly, kidney dysfunction, another complication observed in autistic individuals, impacts clearance of 4EP and its derivatives from circulation. Evidence indicates that accumulation of 4EPS in the brain of mice affects connectivity between subregions, particularly those linked to anxiety. However, we found no data on the presence or quantity of 4EP and/or 4EPS in human brains, irrespective of neurological status, likely due to challenges sampling this organ. We argue that the penetrative ability of 4EP is dependent on its form at the BBB and its physicochemical similarity to endogenous metabolites with dedicated active transport mechanisms across the BBB. We conclude that future research should focus on physical (e.g., ingestion of sorbents) or metabolic mechanisms (e.g., conversion to 4EP-glucuronide) that are capable of being used as interventions to reduce the flux of 4EP from the gut into the body, increase the efflux of 4EP and/or 4EPS from the brain, or increase excretion from the kidneys as a means of addressing the neurological impacts of 4EP.
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Affiliation(s)
- Francesca Day
- Liggins Institute, Waipapa Taumata Rau—The University of Auckland, Auckland, New Zealand
| | - Justin O’Sullivan
- Liggins Institute, Waipapa Taumata Rau—The University of Auckland, Auckland, New Zealand
- The Maurice Wilkins Centre, The University of Auckland, Auckland, New Zealand
- MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, United Kingdom
- Australian Parkinson’s Mission, Garvan Institute of Medical Research, Sydney, NSW, Australia
- A*STAR Singapore Institute for Clinical Sciences, Singapore, Singapore
| | - Chris Pook
- Liggins Institute, Waipapa Taumata Rau—The University of Auckland, Auckland, New Zealand
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Ahmed S, de Vries JC, Lu J, Stuart MHV, Mihăilă SM, Vernooij RWM, Masereeuw R, Gerritsen KGF. Animal Models for Studying Protein-Bound Uremic Toxin Removal-A Systematic Review. Int J Mol Sci 2023; 24:13197. [PMID: 37686004 PMCID: PMC10487432 DOI: 10.3390/ijms241713197] [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: 07/25/2023] [Revised: 08/18/2023] [Accepted: 08/23/2023] [Indexed: 09/10/2023] Open
Abstract
Protein-bound uremic toxins (PBUTs) are associated with the progression of chronic kidney disease (CKD) and its associated morbidity and mortality. The conventional dialysis techniques are unable to efficiently remove PBUTs due to their plasma protein binding. Therefore, novel approaches are being developed, but these require validation in animals before clinical trials can begin. We conducted a systematic review to document PBUT concentrations in various models and species. The search strategy returned 1163 results for which abstracts were screened, resulting in 65 full-text papers for data extraction (rats (n = 41), mice (n = 17), dogs (n = 3), cats (n = 4), goats (n = 1), and pigs (n = 1)). We performed descriptive and comparative analyses on indoxyl sulfate (IS) concentrations in rats and mice. The data on large animals and on other PBUTs were too heterogeneous for pooled analysis. Most rodent studies reported mean uremic concentrations of plasma IS close to or within the range of those during kidney failure in humans, with the highest in tubular injury models in rats. Compared to nephron loss models in rats, a greater rise in plasma IS compared to creatinine was found in tubular injury models, suggesting tubular secretion was more affected than glomerular filtration. In summary, tubular injury rat models may be most relevant for the in vivo validation of novel PBUT-lowering strategies for kidney failure in humans.
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Affiliation(s)
- Sabbir Ahmed
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands; (S.A.); (J.L.); (S.M.M.); (R.M.)
| | - Joost C. de Vries
- Department of Nephrology and Hypertension, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands; (J.C.d.V.); (M.H.V.S.); (R.W.M.V.)
| | - Jingyi Lu
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands; (S.A.); (J.L.); (S.M.M.); (R.M.)
| | - Milan H. Verrijn Stuart
- Department of Nephrology and Hypertension, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands; (J.C.d.V.); (M.H.V.S.); (R.W.M.V.)
| | - Silvia M. Mihăilă
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands; (S.A.); (J.L.); (S.M.M.); (R.M.)
| | - Robin W. M. Vernooij
- Department of Nephrology and Hypertension, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands; (J.C.d.V.); (M.H.V.S.); (R.W.M.V.)
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, 3584 CX Utrecht, The Netherlands
| | - Rosalinde Masereeuw
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands; (S.A.); (J.L.); (S.M.M.); (R.M.)
| | - Karin G. F. Gerritsen
- Department of Nephrology and Hypertension, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands; (J.C.d.V.); (M.H.V.S.); (R.W.M.V.)
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Matsui A, Yoshifuji A, Irie J, Tajima T, Uchiyama K, Itoh T, Wakino S, Itoh H. Canagliflozin protects the cardiovascular system through effects on the gut environment in non-diabetic nephrectomized rats. Clin Exp Nephrol 2023; 27:295-308. [PMID: 36611128 DOI: 10.1007/s10157-022-02312-y] [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: 09/09/2021] [Accepted: 11/30/2022] [Indexed: 01/09/2023]
Abstract
BACKGROUND The gut produces toxins that contribute to the cardiovascular complications of chronic kidney disease. Canagliflozin, a sodium glucose cotransporter (SGLT) 2 inhibitor that is used as an anti-diabetic drug, has a weak inhibitory effect against SGLT1 and may affect the gut glucose concentration and environment. METHODS Here, we determined the effect of canagliflozin on the gut microbiota and the serum gut-derived uremic toxin concentrations in 5/6th nephrectomized (Nx) rats. RESULTS Canagliflozin increased the colonic glucose concentration and restored the number of Lactobacillus bacteria, which was low in Nx rats. In addition, the expression of tight junction proteins in the ascending colon was low in Nx rats, and this was partially restored by canagliflozin. Furthermore, the serum concentrations of gut-derived uremic toxins were significantly increased by Nx and reduced by canagliflozin. Finally, the wall of the thoracic aorta was thicker and there was more cardiac interstitial fibrosis in Nx rats, and these defects were ameliorated by canagliflozin. CONCLUSIONS The increases in colonic glucose concentration, Lactobacillus numbers and tight junction protein expression, and the decreases in serum uremic toxin concentrations and cardiac interstitial fibrosis may have been caused by the inhibition of SGLT1 by canagliflozin because similar effects were not identified in tofogliflozin-treated rats.
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Affiliation(s)
- Ayumi Matsui
- Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjyuku-Ku, Tokyo, 160-8584, Japan
| | - Ayumi Yoshifuji
- Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjyuku-Ku, Tokyo, 160-8584, Japan
| | - Junichiro Irie
- Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjyuku-Ku, Tokyo, 160-8584, Japan
- AMED-CREST, Japan Agency for Medical Research and Development, Tokyo, Japan
| | - Takaya Tajima
- Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjyuku-Ku, Tokyo, 160-8584, Japan
| | - Kiyotaka Uchiyama
- Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjyuku-Ku, Tokyo, 160-8584, Japan
| | - Tomoaki Itoh
- Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjyuku-Ku, Tokyo, 160-8584, Japan
| | - Shu Wakino
- Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjyuku-Ku, Tokyo, 160-8584, Japan.
| | - Hiroshi Itoh
- Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjyuku-Ku, Tokyo, 160-8584, Japan
- AMED-CREST, Japan Agency for Medical Research and Development, Tokyo, Japan
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Ragi N, Pallerla P, Babi Reddy Gari AR, Lingampelly SS, Ketavarapu V, Addipilli R, Chirra N, Kantevari S, Yadla M, Sripadi P. Assessment of uremic toxins in advanced chronic kidney disease patients on maintenance hemodialysis by LC-ESI-MS/MS. Metabolomics 2023; 19:14. [PMID: 36826619 DOI: 10.1007/s11306-023-01978-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 01/23/2023] [Indexed: 02/25/2023]
Abstract
INTRODUCTION In the advanced stage of chronic kidney disease (CKD), electrolytes, fluids, and metabolic wastes including various uremic toxins, accumulate at high concentrations in the patients' blood. Hemodialysis (HD) is the conventional procedure used worldwide to remove metabolic wastes. The creatinine and urea levels have been routinely monitored to estimate kidney function and effectiveness of the HD process. This study, first from in Indian perspective, aimed at the identification and quantification of major uremic toxins in CKD patients on maintenance HD (PRE-HD), and compared with the healthy controls (HC) as well as after HD (POST-HD). OBJECTIVES The study mainly focused on the identification of major uremic toxins in Indian perspective and the quantitative analysis of indoxyl sulfate and p-cresol sulfate (routinely targeted uremic toxins), and phenyl sulfate, catechol sulfate, and guaiacol sulfate (targeted for the first time), apart from creatinine and urea in PRE-HD, POST-HD, and HC groups. METHODS Blood samples were collected from 90 HD patients (both PRE-HD and POST-HD), and 74 HCs. The plasma samples were subjected to direct ESI-HRMS and LC/HRMS for untargeted metabolomics and LC-MS/MS for quantitative analysis. RESULTS Various known uremic toxins, and a few new and unknown peaks were detected in PRE-HD patients. The p-cresol sulfate and indoxyl sulfate were dominant in PRE-HD, the concentrations of phenyl sulfate, catechol sulfate, and guaiacol sulfate were about 50% of that of indoxyl sulfate. Statistical evaluation on the levels of targeted uremic toxins in PRE-HD, POST-HD, and HC groups showed a significant difference among the three groups. The dialytic clearance of indoxyl sulfate and p-cresol sulfate was found to be < 35%, while that of the other three sulfates was 50-58%. CONCLUSION LC-MS/MS method was developed and validated to evaluate five major uremic toxins in CKD patients on HD. The levels of the targeted uremic toxins could be used to assess kidney function and the effectiveness of HD.
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Affiliation(s)
- Nagarjunachary Ragi
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh, 201002, India
- Centre for Mass Spectrometry, Department of Analytical & Structural Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad, Telangana, 500007, India
| | - Pavankumar Pallerla
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh, 201002, India
- Centre for Mass Spectrometry, Department of Analytical & Structural Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad, Telangana, 500007, India
| | | | - Sai Sachin Lingampelly
- Centre for Mass Spectrometry, Department of Analytical & Structural Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad, Telangana, 500007, India
| | | | - Ramunaidu Addipilli
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh, 201002, India
- Centre for Mass Spectrometry, Department of Analytical & Structural Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad, Telangana, 500007, India
| | - Nagaraju Chirra
- Department of Fluoro & Agrochemicals, CSIR-Indian Institute of Chemical Technology, Hyderabad, Telangana, 500007, India
| | - Srinivas Kantevari
- Department of Fluoro & Agrochemicals, CSIR-Indian Institute of Chemical Technology, Hyderabad, Telangana, 500007, India
| | - Manjusha Yadla
- Department of Nephrology, Gandhi Medical College, Gandhi Hospitals, Hyderabad, Telangana, 500025, India.
| | - Prabhakar Sripadi
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh, 201002, India.
- Centre for Mass Spectrometry, Department of Analytical & Structural Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad, Telangana, 500007, India.
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Sivertsson E, Ceder S, Nangaku M, Hansell P, Nordquist L, Palm F. AST-120 to Target Protein-Bound Uremic Toxins Improves Cardiac Output and Kidney Oxygenation in Experimental Chronic Kidney Disease. Kidney Blood Press Res 2023; 48:114-123. [PMID: 36791683 DOI: 10.1159/000529272] [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: 06/02/2022] [Accepted: 01/11/2023] [Indexed: 02/17/2023] Open
Abstract
INTRODUCTION Chronic kidney disease (CKD) is a global health problem with increasing incidence which is closely associated with cardiac dysfunction. In CKD, uremic toxins accumulate as kidney function declines. Additionally, high salt intake is a growing health issue worldwide which can exacerbate kidney disease. In this study, we investigated the effect of reducing plasma levels of protein-bound uremic toxins in a rat model of CKD, challenged with high salt intake and compared the effects to those of conventional treatment using an angiotensin-converting enzyme inhibitor (ACEI). METHODS In rats, the right kidney and 2/3 of the left kidney were surgically removed (5/6 nephrectomy). Animals were fed a normal-salt diet and randomized to either no treatment (control) or chronic treatment with either the oral absorbent AST-120 to reduce plasma levels of protein-bound uremic toxins or the ACEI enalapril to inhibit angiotensin II signaling for 5 weeks. Following treatment, kidney function was measured before and after a week of high salt intake. Cardiac output and markers of oxidative stress were measured at the end of the study period. RESULTS Treatment with AST-120 resulted in decreased levels of the uremic toxin indoxyl sulfate, improved cardiac output (mL/min: AST-120 44.9 ± 5.4 compared to control 26.6 ± 2.0; p < 0.05), and decreased urinary oxidative stress. ACEI reduced oxidative stress in kidney tissue and improved the glomerular filtration rate in response to high salt intake (mL/min: ACEI 1.5 ± 0.1; compared to control 1.1 ± 0.1; p < 0.05). Both interventions improved intrarenal oxygen availability (mm Hg: AST-120 42.8 ± 0.8; ACEI 43.2 ± 1.9; compared to control 33.4 ± 1.3; p < 0.05). CONCLUSION AST-120 administered to reduce plasma levels of uremic toxins, such as indoxyl sulfate, has potential beneficial effects on both cardiac and kidney function. Targeting uremic toxins and angiotensin II signaling simultaneously could be an efficient strategy to target both cardiac and kidney dysfunction in CKD, to further slow progression of disease in patients with CKD.
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Affiliation(s)
- Ebba Sivertsson
- Division of Integrative Physiology, Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Sara Ceder
- Division of Integrative Physiology, Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Masaomi Nangaku
- Division of Nephrology and Endocrinology, University of Tokyo School of Medicine, Tokyo, Japan
| | - Peter Hansell
- Division of Integrative Physiology, Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Lina Nordquist
- Division of Integrative Physiology, Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Fredrik Palm
- Division of Integrative Physiology, Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
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Zhang M, Cui R, Zhou Y, Ma Y, Jin Y, Gou X, Yang J, Wu X. Uric acid accumulation in the kidney triggers mast cell degranulation and aggravates renal oxidative stress. Toxicology 2023; 483:153387. [PMID: 36464070 DOI: 10.1016/j.tox.2022.153387] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 11/17/2022] [Accepted: 11/27/2022] [Indexed: 12/02/2022]
Abstract
The accumulation of uric acid (UA) in the body can lead to the occurrence of hyperuricemia or uric acid nephropathy. Mast cells (MCs) increase oxidative stress and release renin to promote the production of Ang II. The aim of this study was to investigate the effect of UA on MCs in rat kidneys and the association between MCs and renal injury. Our results show that UA accumulation in the kidney stimulated the degranulation of MCs and the release of renin to promote Ang II production, resulting in renal oxidative stress, mitochondrial structural damage, and microvascular system damage. The expression of urate-related transporters was regulated by the UA level and serum urinary toxins levels were substantially elevated in hyperuricemia. Administration of the MCs membrane stabilizer sodium cromoglycate (SCG) or the angiotensin receptor antagonist Valsartan decreased the production of renin and Ang II and relieved renal oxidative stress, mitigated mitochondrial structural damage and microvascular system damage, and promoted the excretion of UA and urinary toxins by increasing the expression of urate-related transporters. These results demonstrate that the accumulation of UA in the kidney can trigger the degranulation of MCs and promote the development of renal oxidative stress. Administration of SCG and Valsartan ameliorated UA-induced renal injury by inhibiting MCs degranulation and reducing renal oxidative stress by inhibiting renin and Ang II production and accelerating renal clearance of UA and uremic toxins.
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Affiliation(s)
- Mingkang Zhang
- School of Pharmacy, Lanzhou University, Lanzhou 730000, China; Engineering Research Centre of Prevention and Control for Clinical Medication Risk, Gansu Province, China
| | - Ruirui Cui
- School of Pharmacy, Lanzhou University, Lanzhou 730000, China; Engineering Research Centre of Prevention and Control for Clinical Medication Risk, Gansu Province, China
| | - Yan Zhou
- Department of Pharmacy, The First Hospital of Lanzhou University, Lanzhou 730000, China; Engineering Research Centre of Prevention and Control for Clinical Medication Risk, Gansu Province, China
| | - Yanrong Ma
- School of Pharmacy, Lanzhou University, Lanzhou 730000, China; Department of Pharmacy, The First Hospital of Lanzhou University, Lanzhou 730000, China; Engineering Research Centre of Prevention and Control for Clinical Medication Risk, Gansu Province, China
| | - Yongwen Jin
- School of Pharmacy, Lanzhou University, Lanzhou 730000, China; Department of Pharmacy, The First Hospital of Lanzhou University, Lanzhou 730000, China; Engineering Research Centre of Prevention and Control for Clinical Medication Risk, Gansu Province, China
| | - Xueyan Gou
- School of Pharmacy, Lanzhou University, Lanzhou 730000, China; Engineering Research Centre of Prevention and Control for Clinical Medication Risk, Gansu Province, China
| | - Jinru Yang
- Department of Pharmacy, The First Hospital of Lanzhou University, Lanzhou 730000, China; Engineering Research Centre of Prevention and Control for Clinical Medication Risk, Gansu Province, China
| | - Xin'an Wu
- School of Pharmacy, Lanzhou University, Lanzhou 730000, China; Department of Pharmacy, The First Hospital of Lanzhou University, Lanzhou 730000, China; Engineering Research Centre of Prevention and Control for Clinical Medication Risk, Gansu Province, China.
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Oe Y, Takahashi N. Tissue Factor, Thrombosis, and Chronic Kidney Disease. Biomedicines 2022; 10:2737. [PMID: 36359257 PMCID: PMC9687479 DOI: 10.3390/biomedicines10112737] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 10/20/2022] [Accepted: 10/24/2022] [Indexed: 11/14/2023] Open
Abstract
Coagulation abnormalities are common in chronic kidney disease (CKD). Tissue factor (TF, factor III) is a master regulator of the extrinsic coagulation system, activating downstream coagulation proteases, such as factor Xa and thrombin, and promoting fibrin formation. TF and coagulation proteases also activate protease-activated receptors (PARs) and are implicated in various organ injuries. Recent studies have shown the mechanisms by which thrombotic tendency is increased under CKD-specific conditions. Uremic toxins, such as indoxyl sulfate and kynurenine, are accumulated in CKD and activate TF and coagulation; in addition, the TF-coagulation protease-PAR pathway enhances inflammation and fibrosis, thereby exacerbating renal injury. Herein, we review the recent research studies to understand the role of TF in increasing the thrombotic risk and CKD progression.
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Affiliation(s)
- Yuji Oe
- Division of Nephrology, Rheumatology, and Endocrinology, Tohoku University Graduate School of Medicine, Sendai 980-8574, Japan
- Division of Nephrology and Hypertension, Department of Medicine, University of California San Diego, La Jolla, CA 92161, USA
- VA San Diego Healthcare System, San Diego, CA 92161, USA
| | - Nobuyuki Takahashi
- Division of Clinical Pharmacology and Therapeutics, Tohoku University Graduate School of Pharmaceutical Sciences & Faculty of Pharmaceutical Sciences, Sendai 980-8578, Japan
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Liu WS, Lin CH, Li SY, Lin CC, Liu TY, Tan AC, Tsou HH, Chan HL, Lai YT. Perfluorooctanesulfonate Can Cause Negative Bias in Creatinine Measurement in Hemodialysis Patients Using Polysulfone Dialysis Membranes. MEMBRANES 2022; 12:778. [PMID: 36005693 PMCID: PMC9413667 DOI: 10.3390/membranes12080778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 08/03/2022] [Accepted: 08/09/2022] [Indexed: 06/15/2023]
Abstract
Serum creatinine is an important clinical marker for renal clearance. However, two conventional methods (Jaffe and enzymatic) are prone to interferences with organic compounds as compared to the standard method (isotope dilution-liquid chromatography-mass spectrometry) and can cause a significant negative bias. Perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA) are two common perfluorochemicals (PFCs) that can easily be accumulated in humans. We aimed to verify whether this bias is the result of an accumulation of PFCs. The serum creatinine values of 124 hemodialysis patients were analyzed using the three methods. We also aimed to evaluate which biochemical parameters will influence the difference between the conventional methods and the standard method. We found that a significant underestimation occurred when using the conventional methods. Albumin is an independent factor associated with negative bias, but it loses this correlation after dialysis, likely due to the removal of protein-bound uremic toxins. PFOS can cause negative bias when using the enzymatic method. Furthermore, this linear correlation is more significant in patients who used polysulfone-based dialysis membranes, possibly due to the better clearance of other uremic toxins. The serum creatinine of uremic patients can be significantly underestimated when using conventional methods. PFCs, as well the type of dialysis membrane being used, can be influencing factors.
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Affiliation(s)
- Wen-Sheng Liu
- Division of Nephrology, Department of Medicine, Taipei City Hospital Zhongxing Branch, Taipei 103, Taiwan
- School of Medicine, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
- College of Science and Engineering, Fu Jen Catholic University, New Taipei City 242, Taiwan
- Institute of Food Safety and Health Risk Assessment, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
- Department of Special Education, University of Taipei, Taipei 100, Taiwan
| | - Chien-Hung Lin
- School of Medicine, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
- College of Science and Engineering, Fu Jen Catholic University, New Taipei City 242, Taiwan
- Department of Pediatrics, Taipei Veterans General Hospital, Taipei 112, Taiwan
| | - Szu-Yuan Li
- School of Medicine, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
- Division of Nephrology, Department of Medicine, Taipei Veterans General Hospital, Taipei 112, Taiwan
| | - Chih-Ching Lin
- School of Medicine, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
- Division of Nephrology, Department of Medicine, Taipei Veterans General Hospital, Taipei 112, Taiwan
| | - Tsung-Yun Liu
- Institute of Food Safety and Health Risk Assessment, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
| | - Ann Charis Tan
- Division of Nephrology, Department of Medicine, Taipei Veterans General Hospital, Taipei 112, Taiwan
| | - Han-Hsing Tsou
- Institute of Food Safety and Health Risk Assessment, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
- Kim Forest Enterprise Co., Ltd., New Taipei City 221, Taiwan
| | - Hsiang-Lin Chan
- Department of Child Psychiatry, Chang Gung Memorial Hospital and University, Taoyuan 333, Taiwan
| | - Yen-Ting Lai
- College of Medicine, National Taiwan University, Taipei 100, Taiwan
- Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital Hsin-Chu Branch, Hsinchu 300, Taiwan
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10
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Ephraim E, Brockman JA, Jewell DE. A Diet Supplemented with Polyphenols, Prebiotics and Omega-3 Fatty Acids Modulates the Intestinal Microbiota and Improves the Profile of Metabolites Linked with Anxiety in Dogs. BIOLOGY 2022; 11:biology11070976. [PMID: 36101356 PMCID: PMC9312346 DOI: 10.3390/biology11070976] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/20/2022] [Accepted: 06/27/2022] [Indexed: 11/23/2022]
Abstract
Simple Summary This study used a nutrition-based approach to examine the effects of foods supplemented with fish oil and a polyphenol blend (citrus pulp, carrot, and spinach) with or without added tomato pomace on anxiety-related biomarkers in dogs. First, all dogs consumed the same initial food, then either the control or test (with tomato pomace) foods, then the washout food, then switched over to the test or control foods, each for 30-day periods. Many more changes in plasma and fecal metabolites were observed when comparing the washout food with the control or test foods than when the control and test foods were compared. Plasma levels of several metabolites that were previously associated with anxiety disorders, including 4-ethylphenyl sulfate, were decreased with the control or test foods compared with the washout food. In addition, bacterial genera that are decreased in the feces of those with anxiety-like disorders were increased following the consumption of the control or test foods. Overall, these data indicate that foods supplemented with omega-3 fatty acids and selected fiber and polyphenol sources lead to beneficial changes in anxiety-related metabolites and gut bacteria. Abstract A nutrition-based approach was utilized to examine the effects of fish oil and a polyphenol blend (with or without tomato pomace) on the fecal microbiota and plasma/fecal metabolomes. Forty dogs, aged 5–14 years, were fed a washout food, then randomized to consume a control (fish oil and polyphenol blend without tomato pomace) or test (fish oil and polyphenol blend with tomato pomace) food, then the washout food, and crossed over to consume the test or control food; each for 30 days. Several metabolites differed when comparing consumption of the washout with either the control or test foods, but few changed significantly between the test and control foods. Plasma levels of 4-ethylphenyl sulfate (4-EPS), a metabolite associated with anxiety disorders, demonstrated the largest decrease between the washout food and the control/test foods. Plasma 4-EPS levels were also significantly lower after dogs ate the test food compared with the control food. Other plasma metabolites linked with anxiety disorders were decreased following consumption of the control/test foods. Significant increases in Blautia, Parabacteroides, and Odoribacter in the fecal microbiota correlated with decreases in 4-EPS when dogs ate the control/test foods. These data indicate that foods supplemented with polyphenols and omega-3 fatty acids can modulate the gut microbiota to improve the profile of anxiety-linked metabolites.
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Affiliation(s)
- Eden Ephraim
- Pet Nutrition Center, Hill’s Pet Nutrition, Topeka, KS 66617, USA;
- Correspondence:
| | | | - Dennis E. Jewell
- Department of Grain Science and Industry, Kansas State University, Manhattan, KS 66506, USA;
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11
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Ahmed S, Sparidans RW, Lu J, Mihaila SM, Gerritsen KGF, Masereeuw R. A robust, accurate, sensitive LC-MS/MS method to measure indoxyl sulfate, validated for plasma and kidney cells. Biomed Chromatogr 2022; 36:e5307. [PMID: 34978088 PMCID: PMC9285569 DOI: 10.1002/bmc.5307] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/07/2021] [Accepted: 12/09/2021] [Indexed: 11/26/2022]
Abstract
Proximal tubular damage is an important prognostic determinant in various chronic kidney diseases (CKDs). Currently available diagnostic methods do not allow for early disease detection and are neither efficient. Indoxyl sulfate (IS) is an endogenous metabolite and protein-bound uremic toxin that is eliminated via renal secretion, but accumulates in plasma during tubular dysfunction. Therefore, it may be suitable as a tubular function marker. To evaluate this, a fast bioanalytical method was developed and validated for IS in various species and a kidney cell line using LC-MS/MS. An isotope-labeled IS potassium salt as an internal standard and acetonitrile (ACN) as a protein precipitant were used for sample pretreatment. The analyte was separated on a Polaris 3 C18-A column by gradient elution using 0.1% formic acid in water and ACN, and detected by negative electrospray ionization in selected reaction monitoring mode. The within-day (≤ 4.0%) and between-day (≤ 4.3%) precisions and accuracies (97.7 to 107.3%) were within the acceptable range. The analyte showed sufficient stability at all conditions investigated. Finally, applying this assay, significantly higher plasma and lower urine concentrations of IS were observed in mice with diabetic nephropathy with tubular damage, which encourages validation toward its use as a biomarker.
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Affiliation(s)
- Sabbir Ahmed
- Division of Pharmacology, Department of Pharmaceutical Sciences, Utrecht Institute for Pharmaceutical SciencesUtrecht UniversityUtrechtThe Netherlands
| | - Rolf W. Sparidans
- Division of Pharmacology, Department of Pharmaceutical Sciences, Utrecht Institute for Pharmaceutical SciencesUtrecht UniversityUtrechtThe Netherlands
| | - Jingyi Lu
- Division of Pharmacology, Department of Pharmaceutical Sciences, Utrecht Institute for Pharmaceutical SciencesUtrecht UniversityUtrechtThe Netherlands
| | - Silvia M. Mihaila
- Division of Pharmacology, Department of Pharmaceutical Sciences, Utrecht Institute for Pharmaceutical SciencesUtrecht UniversityUtrechtThe Netherlands
- Department of Nephrology and HypertensionUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Karin G. F. Gerritsen
- Department of Nephrology and HypertensionUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Rosalinde Masereeuw
- Division of Pharmacology, Department of Pharmaceutical Sciences, Utrecht Institute for Pharmaceutical SciencesUtrecht UniversityUtrechtThe Netherlands
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12
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Sudo N. Possible role of the gut microbiota in the pathogenesis of anorexia nervosa. Biopsychosoc Med 2021; 15:25. [PMID: 34844634 PMCID: PMC8630889 DOI: 10.1186/s13030-021-00228-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Accepted: 11/17/2021] [Indexed: 12/12/2022] Open
Abstract
Anorexia nervosa (AN), an eating disorder, is characterized by extreme weight loss and fear of weight gain. Psychosocial factors are thought to play important roles in the development and progression of AN; however, biological factors also presumably contribute to eating disorders. Recent evidence has shown that the gut microbiota plays an important role in pathogenesis of neuropsychiatric disorders including AN. In this article, we describe the possible role of the gut microbiota in the development and persistence of AN, based on the latest research works, including those of our group.
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Affiliation(s)
- Nobuyuki Sudo
- Department of Psychosomatic Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
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13
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Zheng Y, Bek MK, Prince NZ, Peralta Marzal LN, Garssen J, Perez Pardo P, Kraneveld AD. The Role of Bacterial-Derived Aromatic Amino Acids Metabolites Relevant in Autism Spectrum Disorders: A Comprehensive Review. Front Neurosci 2021; 15:738220. [PMID: 34744609 PMCID: PMC8568365 DOI: 10.3389/fnins.2021.738220] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 09/30/2021] [Indexed: 12/27/2022] Open
Abstract
In recent years, the idea of the gut microbiota being involved in the pathogenesis of autism spectrum disorders (ASD) has attracted attention through numerous studies. Many of these studies report microbial dysregulation in the gut and feces of autistic patients and in ASD animal models. The host microbiota plays a large role in metabolism of ingested foods, and through the production of a range of metabolites it may be involved in neurodevelopmental disorders such as ASD. Two specific microbiota-derived host metabolites, p-cresol sulfate and 4-ethylphenyl sulfate, have been associated with ASD in both patients and animal models. These metabolites originate from bacterially produced p-cresol and 4-ethylphenol, respectively. p-Cresol and 4-ethylphenol are produced through aromatic amino acid fermentation by a range of commensal bacteria, most notably bacteria from the Clostridioides genus, which are among the dysregulated bacteria frequently detected in ASD patients. Once produced, these metabolites are suggested to enter the bloodstream, pass the blood–brain-barrier and affect microglial cells in the central nervous system, possibly affecting processes like neuroinflammation and microglial phagocytosis. This review describes the current knowledge of microbial dysbiosis in ASD and elaborates on the relevance and synthesis pathways of two specific ASD-associated metabolites that may form a link between the microbiota and the brain in autism. While the two discussed metabolites are promising candidates for biomarkers and (nutritional) intervention targets, more research into the role of these metabolites in ASD is required to causally connect these metabolites to ASD pathophysiology.
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Affiliation(s)
- Yuanpeng Zheng
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Utrecht, Netherlands
| | - Marie K Bek
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Utrecht, Netherlands
| | - Naika Z Prince
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Utrecht, Netherlands
| | - Lucia N Peralta Marzal
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Utrecht, Netherlands
| | - Johan Garssen
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Utrecht, Netherlands.,Global Centre of Excellence Immunology, Danone Nutricia Research, Utrecht, Netherlands
| | - Paula Perez Pardo
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Utrecht, Netherlands
| | - Aletta D Kraneveld
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Utrecht, Netherlands
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14
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Wang LC, Tapia LM, Tao X, Chao JE, Thwin O, Zhang H, Thijssen S, Kotanko P, Grobe N. Gut Microbiome-Derived Uremic Toxin Levels in Hemodialysis Patients on Different Phosphate Binder Therapies. Blood Purif 2021; 51:639-648. [PMID: 34375976 PMCID: PMC9393811 DOI: 10.1159/000517470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 05/27/2021] [Indexed: 11/21/2022]
Abstract
Introduction Constipation is prevalent in patients with kidney failure partly due to the use of medication, such as phosphate binders. We hypothesized that serum levels of gut microbiome-derived uremic toxins (UTOX) may be affected by the choice of phosphate binder putatively through its impact on colonic transit time. We investigated two commonly prescribed phosphate binders, sevelamer carbonate (SEV) and sucroferric oxyhydroxide (SFO), and their association with gut microbiome-derived UTOX levels in hemodialysis (HD) patients. Methods Weekly blood samples were collected from 16 anuric HD participants during the 5-week observational period. All participants were on active phosphate binder monotherapy with either SFO or SEV for at least 4 weeks prior to enrollment. Eight UTOX (7 gut microbiome-derived) and tryptophan were quantified using liquid chromatography-mass spectrometry. Serum phosphorus, nutritional, and liver function markers were also measured. For each substance, weekly individual levels, the median concentration per participant, and differences between SFO and SEV groups were reported. Patient-reported bowel movements, by the Bristol Stool Scale (BSS), and pill usage were assessed weekly. Results The SEV group reported a 3.3-fold higher frequency of BSS stool types 1 and 2 (more likely constipated, p < 0.05), whereas the SFO group reported a 1.5-fold higher frequency of BSS stool types 5–7 (more likely loose stool and diarrhea, not significant). Participants in the SFO group showed a trend toward better adherence to phosphate binder therapy (SFO: 87.6% vs. SEV: 66.6%, not significant). UTOX, serum phosphorus, nutritional and liver function markers, and tryptophan were not different between the two groups. Conclusion There was no difference in the gut microbiome-derived UTOX levels between phosphate binders (SFO vs. SEV), despite SFO therapy resulting in fewer constipated participants. This pilot study may inform study design of future clinical trials and highlights the importance of including factors beyond bowel habits and their association with UTOX levels.
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Affiliation(s)
| | | | - Xia Tao
- Renal Research Institute, New York, New York, USA
| | | | - Ohnmar Thwin
- Renal Research Institute, New York, New York, USA
| | - Hanjie Zhang
- Renal Research Institute, New York, New York, USA
| | | | - Peter Kotanko
- Renal Research Institute, New York, New York, USA.,Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Nadja Grobe
- Renal Research Institute, New York, New York, USA
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15
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Gao X, Zhang Y, Mu JQ, Chen KX, Zhang HF, Bi KS. A Metabonomics Study of Guan-Xin-Shu-Tong Capsule against Diet-Induced Hyperlipidemia in Rats. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2021. [DOI: 10.1134/s1068162021020138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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16
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Continuous-flow microfluidic device for synthesis of cationic porous polystyrene microspheres as sorbents of p-xylene from physiological saline. J Flow Chem 2021. [DOI: 10.1007/s41981-021-00142-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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17
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Miyata N, Hata T, Takakura S, Yoshihara K, Morita C, Mikami K, Nomoto K, Miyazaki K, Tsuji H, Sudo N. Metabolomics profile of Japanese female patients with restricting-type anorexia nervosa. Physiol Behav 2021; 228:113204. [PMID: 33053407 DOI: 10.1016/j.physbeh.2020.113204] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 10/07/2020] [Accepted: 10/09/2020] [Indexed: 01/21/2023]
Abstract
In this study, the serum metabolic profiles of 10 female patients with restricting type anorexia nervosa (ANR) were compared to those of 10 age-matched healthy female controls. While the levels of amino acids were lower among the patients than among the controls, the levels of uremic toxins, including p-cresyl sulfate (PCS), indole-3-acetic acid, and phenyl sulfate, were higher in ANR patients. The serum PCS levels correlated positively with the abundance of the Clostridium coccoides group or the C. leptum subgroup in the feces of patients, but not in those of controls. Collectively, these results indicate that the serum metabolic profiles of patients with ANR differ from those of healthy women in terms of both decreased amino acid levels and increased uremic toxins. Gut microbes including C. coccoides or C. leptum may be involved in such an increase in uremic toxins.
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Affiliation(s)
- Noriyuki Miyata
- Department of Psychosomatic Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Tomokazu Hata
- Department of Psychosomatic Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Shu Takakura
- Department of Psychosomatic Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Kazufumi Yoshihara
- Department of Psychosomatic Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Chihiro Morita
- Department of Psychosomatic Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Katsunaka Mikami
- Department of Psychiatry, Tokai University School of Medicine, Isehara, Japan
| | - Koji Nomoto
- Tokyo University of Agriculture, Faculty of Life Sciences, Department of Molecular Microbiology, Japan
| | | | | | - Nobuyuki Sudo
- Department of Psychosomatic Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
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18
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Targeting Uremic Toxins to Prevent Peripheral Vascular Complications in Chronic Kidney Disease. Toxins (Basel) 2020; 12:toxins12120808. [PMID: 33419312 PMCID: PMC7765928 DOI: 10.3390/toxins12120808] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/14/2020] [Accepted: 12/16/2020] [Indexed: 12/24/2022] Open
Abstract
Chronic kidney disease (CKD) exhibits progressive kidney dysfunction and leads to disturbed homeostasis, including accumulation of uremic toxins, activated renin-angiotensin system, and increased oxidative stress and proinflammatory cytokines. Patients with CKD are prone to developing the peripheral vascular disease (PVD), leading to poorer outcomes than those without CKD. Cumulative evidence has showed that the synergy of uremic milieu and PVD could exaggerate vascular complications such as limb ischemia, amputation, stenosis, or thrombosis of a dialysis vascular access, and increase mortality risk. The role of uremic toxins in the pathogenesis of vascular dysfunction in CKD has been investigated. Moreover, growing evidence has shown the promising role of uremic toxins as a therapeutic target for PVD in CKD. This review focused on uremic toxins in the pathophysiology, in vitro and animal models, and current novel clinical approaches in reducing the uremic toxin to prevent peripheral vascular complications in CKD patients.
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19
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Roth-Stefanski CT, Dolenga C, Nakao LS, Pecoits-Filho R, de Moraes TP, Moreno-Amaral AN. Pilot Study of Probiotic Supplementation on Uremic Toxicity and Inflammatory Cytokines in Chronic Kidney Patients. CURRENT NUTRITION & FOOD SCIENCE 2020. [DOI: 10.2174/1573401315666190215111402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Background:
Bacterial metabolism contributes to the generation of uremic toxins in patients
with chronic kidney disease (CKD). It has been investigated the use of probiotics in the reduction
of uremic toxins intestinal production.
Objective:
The aim of this pilot study was to evaluate the effect of probiotic supplementation on reducing
the production of uremic toxins and the inflammatory profile of CKD patients.
Methods:
We performed a randomized, blind, placebo-controlled, crossover study on patients with
CKD stages 3 and 4. The intervention was a probiotic formulation composed of Lactobacillus
acidophilus strains given orally three times a day for 3 months. Changes in uremic toxins
(p-Cresylsulfate and Indoxyl Sulfate) and serum inflammatory cytokines were the primary endpoints.
Results:
Of the 44 patients randomized, 25 completed the study (mean age 51 ± 9.34, 64% female,
mean eGFR 36 ± 14.26 mL/min/1.73m², mean BMI 28.5 ± 5.75 kg/m²). At 3 months, there were no
significant changes in any of the studied biomarkers including p-cresylsulfate (p = 0.57), Indoxyl sulfate
(p = 0.08) and interleukin-6 (p = 0.55).
Conclusion:
Lactobacillus acidophilus strains given as probiotic were not able to reduce serum levels
of uremic toxins and biomarkers of inflammation in CKD patients in stage 3 and 4.
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Affiliation(s)
- Cristina T. Roth-Stefanski
- Department of Postgraduate in Health Science (PPGCS), Medical School, Pontifical Catholic University of Parana, Rua Imaculada Conceicao, 1155, Curitiba, Brazil
| | - Carla Dolenga
- Basic Pathology Department, UFPR, Curitiba/PR, Brazil
| | - Lia S. Nakao
- Basic Pathology Department, UFPR, Curitiba/PR, Brazil
| | - Roberto Pecoits-Filho
- Department of Postgraduate in Health Science (PPGCS), Medical School, Pontifical Catholic University of Parana, Rua Imaculada Conceicao, 1155, Curitiba, Brazil
| | - Thyago P. de Moraes
- Department of Postgraduate in Health Science (PPGCS), Medical School, Pontifical Catholic University of Parana, Rua Imaculada Conceicao, 1155, Curitiba, Brazil
| | - Andrea N. Moreno-Amaral
- Department of Postgraduate in Health Science (PPGCS), Medical School, Pontifical Catholic University of Parana, Rua Imaculada Conceicao, 1155, Curitiba, Brazil
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20
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Wernimont SM, Radosevich J, Jackson MI, Ephraim E, Badri DV, MacLeay JM, Jewell DE, Suchodolski JS. The Effects of Nutrition on the Gastrointestinal Microbiome of Cats and Dogs: Impact on Health and Disease. Front Microbiol 2020; 11:1266. [PMID: 32670224 PMCID: PMC7329990 DOI: 10.3389/fmicb.2020.01266] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 05/18/2020] [Indexed: 12/12/2022] Open
Abstract
The gastrointestinal (GI) microbiome of cats and dogs is increasingly recognized as a metabolically active organ inextricably linked to pet health. Food serves as a substrate for the GI microbiome of cats and dogs and plays a significant role in defining the composition and metabolism of the GI microbiome. The microbiome, in turn, facilitates the host's nutrient digestion and the production of postbiotics, which are bacterially derived compounds that can influence pet health. Consequently, pet owners have a role in shaping the microbiome of cats and dogs through the food they choose to provide. Yet, a clear understanding of the impact these food choices have on the microbiome, and thus on the overall health of the pet, is lacking. Pet foods are formulated to contain the typical nutritional building blocks of carbohydrates, proteins, and fats, but increasingly include microbiome-targeted ingredients, such as prebiotics and probiotics. Each of these categories, as well as their relative proportions in food, can affect the composition and/or function of the microbiome. Accumulating evidence suggests that dietary components may impact not only GI disease, but also allergies, oral health, weight management, diabetes, and kidney disease through changes in the GI microbiome. Until recently, the focus of microbiome research was to characterize alterations in microbiome composition in disease states, while less research effort has been devoted to understanding how changes in nutrition can influence pet health by modifying the microbiome function. This review summarizes the impact of pet food nutritional components on the composition and function of the microbiome and examines evidence for the role of nutrition in impacting host health through the microbiome in a variety of disease states. Understanding how nutrition can modulate GI microbiome composition and function may reveal new avenues for enhancing the health and resilience of cats and dogs.
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Affiliation(s)
| | | | | | - Eden Ephraim
- Hill’s Pet Nutrition, Inc., Topeka, KS, United States
| | | | | | - Dennis E. Jewell
- Department of Grain Science and Industry, Kansas State University, Manhattan, KS, United States
| | - Jan S. Suchodolski
- Texas A&M College of Veterinary Medicine & Biomedical Sciences, College Station, TX, United States
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21
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Bush KT, Singh P, Nigam SK. Gut-derived uremic toxin handling in vivo requires OAT-mediated tubular secretion in chronic kidney disease. JCI Insight 2020; 5:133817. [PMID: 32271169 DOI: 10.1172/jci.insight.133817] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 02/28/2020] [Indexed: 12/12/2022] Open
Abstract
The role of the renal organic anion transporters OAT1 (also known as SLC22A6, originally identified as NKT) and OAT3 (also known as SLC22A8) in chronic kidney disease (CKD) remains poorly understood. This is particularly so from the viewpoint of residual proximal tubular secretion, a key adaptive mechanism to deal with protein-bound uremic toxins in CKD. Using the subtotal nephrectomy (STN) model, plasma metabolites accumulating in STN rats treated with and without the OAT inhibitor, probenecid, were identified. Comparisons with metabolomics data from Oat1-KO and Oat3-KO mice support the centrality of the OATs in residual tubular secretion of uremic solutes, such as indoxyl sulfate, kynurenate, and anthranilate. Overlapping our data with those of published metabolomics data regarding gut microbiome-derived uremic solutes - which can have dual roles in signaling and toxicity - indicates that OATs play a critical role in determining their plasma levels in CKD. Thus, the OATs, along with other SLC and ABC drug transporters, are critical to the movement of uremic solutes across tissues and into various body fluids, consistent with the remote sensing and signaling theory. The data support a role for OATs in modulating remote interorganismal and interorgan communication (gut microbiota-blood-liver-kidney-urine). The results also have implications for understanding drug-metabolite interactions involving uremic toxins.
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Affiliation(s)
- Kevin T Bush
- Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
| | - Prabhleen Singh
- Division of Nephrology-Hypertension, University of California, San Diego and Veterans Affairs San Diego Healthcare System, San Diego, California, USA.,Department of Medicine, University of California, San Diego, La Jolla, California, USA
| | - Sanjay K Nigam
- Department of Pediatrics, University of California, San Diego, La Jolla, California, USA.,Department of Medicine, University of California, San Diego, La Jolla, California, USA
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22
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Higher cerebrospinal fluid to plasma ratio of p-cresol sulfate and indoxyl sulfate in patients with Parkinson's disease. Clin Chim Acta 2019; 501:165-173. [PMID: 31726035 DOI: 10.1016/j.cca.2019.10.038] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 10/24/2019] [Accepted: 10/24/2019] [Indexed: 12/11/2022]
Abstract
BACKGROUND In Parkinson's disease (PD), impairment of brain to blood barrier and/or blood-cerebrospinal fluid (CSF) barrier is described. It can increase the level of uremic toxins in CSF. So far, role of these compounds in neurological disorders has not been completely understood. However, a link has been observed between chronic kidney disease and neurological disorders. We measured the concentrations of uremic toxins (i.e. indoxyl sulfate (IS), p-cresol sulfate (pCS), symmetric dimethylarginine (SDMA), asymmetric dimethylarginine (ADMA), and trimethylamine N-oxide (TMAO)) in CSF and plasma, and correlated them with inflammation and oxidative stress biomarkers. METHODS Plasma and CSF samples were collected from 27 volunteers (18 with PD and 9 controls). The level of toxins was determined using liquid chromatography coupled with tandem mass spectrometry. RESULTS In PD, for IS and pCS, CSF-plasma ratio was higher. Concentration of pCS in CSF was higher in PD compared to controls. TMAO level was also higher in plasma of that group. Patients with motor fluctuations had higher level of uremic toxins in CSF, but not in plasma. CONCLUSIONS The level of pCS and IS in CSF of PD is higher than expected, based on their blood level. It can influence pathogenesis and progression of PD.
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23
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Development and validation of a UHPLC-MS/MS method for measurement of a gut-derived uremic toxin panel in human serum: An application in patients with kidney disease. J Pharm Biomed Anal 2019; 174:618-624. [PMID: 31276982 DOI: 10.1016/j.jpba.2019.06.033] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 06/16/2019] [Accepted: 06/22/2019] [Indexed: 12/30/2022]
Abstract
Gut-derived uremic toxins contribute to the uremic syndrome and are gaining attention as potentially modifiable cardiovascular disease risk factors in patients with underlying chronic kidney disease. A simple, rapid, robust, accurate and precise ultra-performance liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous determination of a panel of four gut-derived uremic toxins in human serum. The panel was comprised of kynurenic acid, hippuric acid, indoxyl sulfate, and p-cresol sulfate. Serum samples were protein precipitated with acetonitrile containing deuterated internal standards. Chromatographic separation of analytes was accomplished with an Acquity BEH C18 (2.1 × 100 mm, 1.7 μm) column by isocratic elution at a flow rate of 0.3 mL/min with a mobile phase composed of solvent A (10 mM ammonium formate; pH 4.3) and solvent B (acetonitrile) (85:15, v/v). Analytes were detected using heated electrospray ionization and selected reaction monitoring. The total run-time was 4 min. Standard curves were linear and correlation coefficients (r) were ≥0.997 for concentration ranges of 0.01-0.5 μg/mL for kynurenic acid, 0.25-80 μg/mL for p-cresol sulfate, and 0.2-80 μg/mL for hippuric acid and indoxyl sulfate. Intra- and inter-day accuracy and precision were within 19.3% for the LLOQs and ≤10.9% for all other quality controls. Matrix effect from serum was <15% and recovery was ≥81.3% for all analytes. The method utilizes a short run-time, simple/inexpensive sample processing, has passed FDA validation recommendations, and was successfully applied to study patients with kidney disease.
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Emerging Roles of Aryl Hydrocarbon Receptors in the Altered Clearance of Drugs during Chronic Kidney Disease. Toxins (Basel) 2019; 11:toxins11040209. [PMID: 30959953 PMCID: PMC6521271 DOI: 10.3390/toxins11040209] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 03/12/2019] [Accepted: 04/03/2019] [Indexed: 12/11/2022] Open
Abstract
Chronic kidney disease (CKD) is a major public health problem, since 300,000,000 people in the world display a glomerular filtration rate (GFR) below 60 mL/min/1.73m². Patients with CKD have high rates of complications and comorbidities. Thus, they require the prescription of numerous medications, making the management of patients very complex. The prescription of numerous drugs associated with an altered renal- and non-renal clearance makes dose adjustment challenging in these patients, with frequent drug-related adverse events. However, the mechanisms involved in this abnormal drug clearance during CKD are not still well identified. We propose here that the transcription factor, aryl hydrocarbon receptor, which is the cellular receptor for indolic uremic toxins, could worsen the metabolism and the excretion of drugs in CKD patients.
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AST-120, an Adsorbent of Uremic Toxins, Improves the Pathophysiology of Heart Failure in Conscious Dogs. Cardiovasc Drugs Ther 2019; 33:277-286. [PMID: 30903544 DOI: 10.1007/s10557-019-06875-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
PURPOSE Several lines of evidence suggest that renal dysfunction is associated with cardiovascular toxicity through the action of uremic toxins. The levels of those uremic toxins can be reportedly reduced by the spherical carbon adsorbent AST-120. Because heart failure (HF) causes renal dysfunction by low cardiac output and renal edema, the removal of uremic toxins could be cardioprotective. METHOD To determine whether blood levels of the uremic toxin indoxyl sulfate (IS) increase in HF and whether AST-120 can reduce those levels and improve HF. We induced HF in 12 beagle dogs by 6 weeks of rapid right ventricular pacing at 230 beats per min. We treated six dogs with a 1-g/kg/day oral dosage of AST-120 for 14 days from week 4 after the start of rapid ventricular pacing. The other six dogs did not receive any treatment (control group). RESULTS In the untreated dogs, IS levels increased as cardiac function deteriorated. In contrast, plasma IS levels in the treated dogs decreased to baseline levels, with both left ventricular fractional shortening and pulmonary capillary wedge pressure also improving when compared with untreated dogs. Finally, AST-120 treatment was shown to reduce both myocardial apoptosis and fibrosis along with decreases in extracellular signal-regulated kinase phosphorylation, the Bax/Bcl-2 ratio, and TGF-β1 expression and increases in AKT phosphorylation. CONCLUSIONS IS levels are increased in HF. AST-120 treatment reduces the levels of IS and improves the pathophysiology of HF in a canine model. AST-120 could be a novel candidate for the treatment of HF.
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Mair RD, Sirich TL, Plummer NS, Meyer TW. Characteristics of Colon-Derived Uremic Solutes. Clin J Am Soc Nephrol 2018; 13:1398-1404. [PMID: 30087103 PMCID: PMC6140561 DOI: 10.2215/cjn.03150318] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 06/13/2018] [Indexed: 12/14/2022]
Abstract
BACKGROUND AND OBJECTIVES Colon microbial metabolism produces solutes that are normally excreted in the urine and accumulate in the plasma when the kidneys fail. This study sought to further identify and characterize human colon-derived uremic solutes. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Colon-derived solutes normally excreted in the urine were identified by comparing urine from controls (n=17) and patients with total colectomies (n=12), using an established metabolomic platform. Colon-derived solutes that accumulate in kidney failure were then identified by comparing the plasma of the control patients with that of patients on dialysis (n=14). RESULTS Ninety-one urinary solutes were classified as colon-derived on the basis of the finding of a urine excretion rate at least four-fold higher in control patients than in patients with total colectomies. Forty-six were solutes with known chemical structure, 35 of which had not previously been identified as colon-derived. Sixty of the colon-derived solutes accumulated in the plasma of patients with ESKD to a degree greater than urea and were therefore classified as uremic. The estimated urinary clearance for 27 out of the 32 colon-derived solutes for which clearance could be calculated exceeded that of creatinine, consistent with tubular secretion. Sulfatase treatment revealed that 42 out of the 91 colon-derived solutes detected were likely conjugates. CONCLUSIONS Metabolomic analysis identified numerous colon-derived solutes that are normally excreted in human urine. Clearance by tubular secretion limits plasma levels of many colon-derived solutes.
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Affiliation(s)
- Robert D Mair
- Department of Medicine, Veterans Affairs Palo Alto Health Care System and Stanford University, Palo Alto, California
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Kanemitsu Y, Tsukamoto H, Matsumoto Y, Nozawa-Kumada K, Kondo Y, Abe T, Tomioka Y. Generation and Characterization of Anti-phenyl Sulfate Monoclonal Antibodies and a Potential Use for Phenyl Sulfate Analysis in Human Blood. Biol Pharm Bull 2018; 41:1170-1177. [PMID: 30068866 DOI: 10.1248/bpb.b17-00925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Patients with chronic kidney disease (CKD) have increased blood levels of phenyl sulfate (PS), a circulating uremic toxin. In this study, we produced anti-PS monoclonal antibodies (mAbs) and characterized their cross-reactivity to structural PS analogs. To induce PS-specific mAbs, we synthesized 4-mercaptophenyl sulfate with a sulfhydryl group at the para-position of PS and conjugated it to carrier proteins via bifunctional linkers. Using these PS conjugates as immunogens and as antigens for enzyme-linked immunosorbent assay (ELISA) screening, we produced by a hybridoma method two novel mAbs (YK33.1 and YKS19.2) that react with PS conjugates independent of carrier and linker structures. Although all of the PS analogs tested, with the exception of indoxyl sulfate, were cross-reactive to both mAbs in phosphate buffered saline (PBS), PS specificity for YKS19.2 was enhanced in human plasma and serum. YKS19.2 mAb was cross-reactive only with o-cresyl sulfate, which is absent in human blood. PS sensitivity for YKS19.2 mAb increased to an IC50 of 10.4 µg/mL when 0.1% Tween 20 was added in a primary competitive reaction. To explore potential clinical applications, we determined concentrations of PS in serum samples from 19 CKD patients by inhibition ELISA using YKS19.2 mAb and compared them to those found using an LC-MS/MS method. A good correlation was observed between each value (R2=0.825). Therefore, the unique antigen specificity of YKS19.2 mAb could be useful for prescreening of patients with accumulated PS or for comprehensive analysis of uremic toxins that have a PS-like structure.
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Affiliation(s)
- Yoshitomi Kanemitsu
- Laboratory of Oncology, Pharmacy Practice and Sciences, Graduate School of Pharmaceutical Sciences, Tohoku University
| | - Hiroki Tsukamoto
- Laboratory of Oncology, Pharmacy Practice and Sciences, Graduate School of Pharmaceutical Sciences, Tohoku University
| | - Yotaro Matsumoto
- Laboratory of Oncology, Pharmacy Practice and Sciences, Graduate School of Pharmaceutical Sciences, Tohoku University
| | - Kanako Nozawa-Kumada
- Laboratory of Molecular Transformation, Graduate School of Pharmaceutical Sciences, Tohoku University
| | - Yoshinori Kondo
- Laboratory of Molecular Transformation, Graduate School of Pharmaceutical Sciences, Tohoku University
| | - Takaaki Abe
- Department of Medical Science, Graduate School of Biomedical Engineering, Tohoku University.,Department of Clinical Biology and Hormonal Regulation, Graduate School of Medicine, Tohoku University
| | - Yoshihisa Tomioka
- Laboratory of Oncology, Pharmacy Practice and Sciences, Graduate School of Pharmaceutical Sciences, Tohoku University
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Vanholder R, Van Laecke S, Glorieux G, Verbeke F, Castillo-Rodriguez E, Ortiz A. Deleting Death and Dialysis: Conservative Care of Cardio-Vascular Risk and Kidney Function Loss in Chronic Kidney Disease (CKD). Toxins (Basel) 2018; 10:E237. [PMID: 29895722 PMCID: PMC6024824 DOI: 10.3390/toxins10060237] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 05/11/2018] [Indexed: 02/07/2023] Open
Abstract
The uremic syndrome, which is the clinical expression of chronic kidney disease (CKD), is a complex amalgam of accelerated aging and organ dysfunctions, whereby cardio-vascular disease plays a capital role. In this narrative review, we offer a summary of the current conservative (medical) treatment options for cardio-vascular and overall morbidity and mortality risk in CKD. Since the progression of CKD is also associated with a higher cardio-vascular risk, we summarize the interventions that may prevent the progression of CKD as well. We pay attention to established therapies, as well as to novel promising options. Approaches that have been considered are not limited to pharmacological approaches but take into account lifestyle measures and diet as well. We took as many randomized controlled hard endpoint outcome trials as possible into account, although observational studies and post hoc analyses were included where appropriate. We also considered health economic aspects. Based on this information, we constructed comprehensive tables summarizing the available therapeutic options and the number and kind of studies (controlled or not, contradictory outcomes or not) with regard to each approach. Our review underscores the scarcity of well-designed large controlled trials in CKD. Nevertheless, based on the controlled and observational data, a therapeutic algorithm can be developed for this complex and multifactorial condition. It is likely that interventions should be aimed at targeting several modifiable factors simultaneously.
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Affiliation(s)
- Raymond Vanholder
- Nephrology Section, Department of Internal Medicine, Ghent University Hospital, 9000 Ghent, Belgium.
| | - Steven Van Laecke
- Nephrology Section, Department of Internal Medicine, Ghent University Hospital, 9000 Ghent, Belgium.
| | - Griet Glorieux
- Nephrology Section, Department of Internal Medicine, Ghent University Hospital, 9000 Ghent, Belgium.
| | - Francis Verbeke
- Nephrology Section, Department of Internal Medicine, Ghent University Hospital, 9000 Ghent, Belgium.
| | | | - Alberto Ortiz
- Department of Nephrology and Hypertension, IIS-Fundacion Jimenez Diaz UAM, 28040 Madrid, Spain.
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Uremic Toxin Clearance and Cardiovascular Toxicities. Toxins (Basel) 2018; 10:toxins10060226. [PMID: 29865226 PMCID: PMC6024759 DOI: 10.3390/toxins10060226] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 05/25/2018] [Accepted: 05/31/2018] [Indexed: 12/31/2022] Open
Abstract
Uremic solutes contribute to cardiovascular disease in renal insufficiency. In this review we describe the clearance of selected uremic solutes, which have been associated with cardiovascular disease. These solutes—indoxyl sulfate (IS), p-cresol sulfate (PCS), phenylacetylglutamine (PAG), trimethylamine-n-oxide (TMAO), and kynurenine—exemplify different mechanisms of clearance. IS and PCS are protein-bound solutes efficiently cleared by the native kidney through tubular secretion. PAG and TMAO are not protein-bound but are also cleared by the native kidney through tubular secretion, while kynurenine is not normally cleared by the kidney. Increases in the plasma levels of the normally secreted solutes IS, PCS, TMAO, and PAG in chronic kidney disease (CKD) are attributable to a reduction in their renal clearances. Levels of each of these potential toxins are even higher in patients on dialysis than in those with advanced chronic kidney disease, which can be accounted for in part by a low ratio of dialytic to native kidney clearance. The rise in plasma kynurenine in CKD and dialysis patients, by contrast, remains to be explained. Our ability to detect lower levels of the potential uremic cardiovascular toxins with renal replacement therapy may be limited by the intermittency of treatment, by increases in solute production, and by the presence of non-renal clearance. Reduction in the levels of uremic cardiovascular toxins may in the future be achieved more effectively by inhibiting their production.
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Abstract
Uremic solutes contribute to cardiovascular disease in renal insufficiency. In this review we describe the clearance of selected uremic solutes, which have been associated with cardiovascular disease. These solutes-indoxyl sulfate (IS), p-cresol sulfate (PCS), phenylacetylglutamine (PAG), trimethylamine-n-oxide (TMAO), and kynurenine-exemplify different mechanisms of clearance. IS and PCS are protein-bound solutes efficiently cleared by the native kidney through tubular secretion. PAG and TMAO are not protein-bound but are also cleared by the native kidney through tubular secretion, while kynurenine is not normally cleared by the kidney. Increases in the plasma levels of the normally secreted solutes IS, PCS, TMAO, and PAG in chronic kidney disease (CKD) are attributable to a reduction in their renal clearances. Levels of each of these potential toxins are even higher in patients on dialysis than in those with advanced chronic kidney disease, which can be accounted for in part by a low ratio of dialytic to native kidney clearance. The rise in plasma kynurenine in CKD and dialysis patients, by contrast, remains to be explained. Our ability to detect lower levels of the potential uremic cardiovascular toxins with renal replacement therapy may be limited by the intermittency of treatment, by increases in solute production, and by the presence of non-renal clearance. Reduction in the levels of uremic cardiovascular toxins may in the future be achieved more effectively by inhibiting their production.
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Affiliation(s)
- Robert D Mair
- The Departments of Medicine, VA Palo Alto Healthcare System, 111R, 3801 Miranda Ave., Palo Alto, CA 94304, USA.
- Division of Nephrology, Stanford University, 777 Welch Road, Suite DE, Palo Alto, CA 94304, USA.
| | - Tammy L Sirich
- The Departments of Medicine, VA Palo Alto Healthcare System, 111R, 3801 Miranda Ave., Palo Alto, CA 94304, USA.
- Division of Nephrology, Stanford University, 777 Welch Road, Suite DE, Palo Alto, CA 94304, USA.
| | - Timothy W Meyer
- The Departments of Medicine, VA Palo Alto Healthcare System, 111R, 3801 Miranda Ave., Palo Alto, CA 94304, USA.
- Division of Nephrology, Stanford University, 777 Welch Road, Suite DE, Palo Alto, CA 94304, USA.
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Edamatsu T, Fujieda A, Itoh Y. Phenyl sulfate, indoxyl sulfate and p-cresyl sulfate decrease glutathione level to render cells vulnerable to oxidative stress in renal tubular cells. PLoS One 2018; 13:e0193342. [PMID: 29474405 PMCID: PMC5825083 DOI: 10.1371/journal.pone.0193342] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 02/08/2018] [Indexed: 12/30/2022] Open
Abstract
In chronic kidney disease patients, oxidative stress is generally associated with disease progression and pathogenesis of its comorbidities. Phenyl sulfate is a protein-bound uremic solute, which accumulates in chronic kidney disease patients, but little is known about its nature. Although many reports revealed that protein-bound uremic solutes induce reactive oxygen species production, the effects of these solutes on anti-oxidant level have not been well studied. Therefore, we examined the effects of protein-bound uremic solutes on glutathione levels. As a result, indoxyl sulfate, phenyl sulfate, and p-cresyl sulfate decreased glutathione levels in porcine renal tubular cells. Next we examined whether phenyl sulfate-treated cells becomes vulnerable to oxidative stress. In phenyl sulfate-treated cells, hydrogen peroxide induced higher rates of cell death than in control cells. Buthionine sulfoximine, which is known to decrease glutathione level, well mimicked the effect of phenyl sulfate. Finally, we evaluated a mixture of indoxyl sulfate, phenyl sulfate, and p-cresyl sulfate at concentrations comparable to the serum concentrations of hemodialysis patients, and we confirmed its decreasing effect on glutathione level. In conclusion, indoxyl sulfate, phenyl sulfate, and p-cresyl sulfate decrease glutathione levels, rendering the cells vulnerable to oxidative stress.
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Affiliation(s)
- Takeo Edamatsu
- Pharmaceuticals & Agrochemicals Division, Kureha Corporation, Tokyo, Japan
- * E-mail:
| | - Ayako Fujieda
- Pharmaceuticals & Agrochemicals Division, Kureha Corporation, Tokyo, Japan
| | - Yoshiharu Itoh
- Pharmaceuticals & Agrochemicals Division, Kureha Corporation, Tokyo, Japan
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Derkach A, Sampson J, Joseph J, Playdon MC, Stolzenberg-Solomon RZ. Effects of dietary sodium on metabolites: the Dietary Approaches to Stop Hypertension (DASH)-Sodium Feeding Study. Am J Clin Nutr 2017; 106:1131-1141. [PMID: 28855223 PMCID: PMC5611778 DOI: 10.3945/ajcn.116.150136] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 08/01/2017] [Indexed: 12/25/2022] Open
Abstract
Background: High sodium intake is known to increase blood pressure and is difficult to measure in epidemiologic studies.Objective: We examined the effect of sodium intake on metabolites within the DASH (Dietary Approaches to Stop Hypertension Trial)-Sodium Trial to further our understanding of the biological effects of sodium intake beyond blood pressure.Design: The DASH-Sodium Trial randomly assigned individuals to either the DASH diet (low in fat and high in protein, low-fat dairy, and fruits and vegetables) or a control diet for 12 wk. Participants within each diet arm received, in random order, diets containing high (150 nmol or 3450 mg), medium (100 nmol or 2300 mg), and low (50 nmol or 1150 mg) amounts of sodium for 30 d (crossover design). Fasting blood samples were collected at the end of each sodium intervention. We measured 531 identified plasma metabolites in 73 participants at the end of their high- and low-sodium interventions and in 46 participants at the end of their high- and medium-sodium interventions (N = 119). We used linear mixed-effects regression to model the relation between each log-transformed metabolite and sodium intake. We also combined the resulting P values with Fisher's method to estimate the association between sodium intake and 38 metabolic pathways or groups.Results: Six pathways were associated with sodium intake at a Bonferroni-corrected threshold of 0.0013 (e.g., fatty acid, food component or plant, benzoate, γ-glutamyl amino acid, methionine, and tryptophan). Although 82 metabolites were associated with sodium intake at a false discovery rate ≤0.10, only 4-ethylphenylsufate, a xenobiotic related to benzoate metabolism, was significant at a Bonferroni-corrected threshold (P < 10-5). Adjustment for coinciding change in blood pressure did not substantively alter the association for the top-ranked metabolites.Conclusion: Sodium intake is associated with changes in circulating metabolites, including gut microbial, tryptophan, plant component, and γ-glutamyl amino acid-related metabolites. This trial was registered at clinicaltrials.gov as NCT00000608.
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Affiliation(s)
- Andriy Derkach
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Rockville, MD; and
| | - Joshua Sampson
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Rockville, MD; and
| | - Justin Joseph
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Rockville, MD; and,Department of Chemistry, Virginia Commonwealth University, Richmond, VA
| | - Mary C Playdon
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Rockville, MD; and
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Gryp T, Vanholder R, Vaneechoutte M, Glorieux G. p-Cresyl Sulfate. Toxins (Basel) 2017; 9:toxins9020052. [PMID: 28146081 PMCID: PMC5331431 DOI: 10.3390/toxins9020052] [Citation(s) in RCA: 229] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 01/12/2017] [Accepted: 01/23/2017] [Indexed: 12/16/2022] Open
Abstract
If chronic kidney disease (CKD) is associated with an impairment of kidney function, several uremic solutes are retained. Some of these exert toxic effects, which are called uremic toxins. p-Cresyl sulfate (pCS) is a prototype protein-bound uremic toxin to which many biological and biochemical (toxic) effects have been attributed. In addition, increased levels of pCS have been associated with worsening outcomes in CKD patients. pCS finds its origin in the intestine where gut bacteria metabolize aromatic amino acids, such as tyrosine and phenylalanine, leading to phenolic end products, of which pCS is one of the components. In this review we summarize the biological effects of pCS and its metabolic origin in the intestine. It appears that, according to in vitro studies, the intestinal bacteria generating phenolic compounds mainly belong to the families Bacteroidaceae, Bifidobacteriaceae, Clostridiaceae, Enterobacteriaceae, Enterococcaceae, Eubacteriaceae, Fusobacteriaceae, Lachnospiraceae, Lactobacillaceae, Porphyromonadaceae, Staphylococcaceae, Ruminococcaceae, and Veillonellaceae. Since pCS remains difficult to remove by dialysis, the gut microbiota could be a future target to decrease pCS levels and its toxicity, even at earlier stages of CKD, aiming at slowing down the progression of the disease and decreasing the cardiovascular burden.
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Affiliation(s)
- Tessa Gryp
- Department of Internal Medicine, Nephrology Division, Ghent University Hospital, 9000 Ghent, Belgium.
- Laboratory for Bacteriology Research, Department of Clinical Chemistry, Microbiology & Immunology, Ghent University, 9000 Ghent, Belgium.
| | - Raymond Vanholder
- Department of Internal Medicine, Nephrology Division, Ghent University Hospital, 9000 Ghent, Belgium.
| | - Mario Vaneechoutte
- Laboratory for Bacteriology Research, Department of Clinical Chemistry, Microbiology & Immunology, Ghent University, 9000 Ghent, Belgium.
| | - Griet Glorieux
- Department of Internal Medicine, Nephrology Division, Ghent University Hospital, 9000 Ghent, Belgium.
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Lustgarten MS, Price LL, Phillips EM, Kirn DR, Mills J, Fielding RA. Serum Predictors of Percent Lean Mass in Young Adults. J Strength Cond Res 2016; 30:2194-201. [PMID: 23774283 DOI: 10.1519/jsc.0b013e31829eef24] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Lustgarten, MS, Price, LL, Phillips, EM, Kirn, DR, Mills, J, and Fielding, RA. Serum predictors of percent lean mass in young adults. J Strength Cond Res 30(8): 2194-2201, 2016-Elevated lean (skeletal muscle) mass is associated with increased muscle strength and anaerobic exercise performance, whereas low levels of lean mass are associated with insulin resistance and sarcopenia. Therefore, studies aimed at obtaining an improved understanding of mechanisms related to the quantity of lean mass are of interest. Percent lean mass (total lean mass/body weight × 100) in 77 young subjects (18-35 years) was measured with dual-energy x-ray absorptiometry. Twenty analytes and 296 metabolites were evaluated with the use of the standard chemistry screen and mass spectrometry-based metabolomic profiling, respectively. Sex-adjusted multivariable linear regression was used to determine serum analytes and metabolites significantly (p ≤ 0.05 and q ≤ 0.30) associated with the percent lean mass. Two enzymes (alkaline phosphatase and serum glutamate oxaloacetate aminotransferase) and 29 metabolites were found to be significantly associated with the percent lean mass, including metabolites related to microbial metabolism, uremia, inflammation, oxidative stress, branched-chain amino acid metabolism, insulin sensitivity, glycerolipid metabolism, and xenobiotics. Use of sex-adjusted stepwise regression to obtain a final covariate predictor model identified the combination of 5 analytes and metabolites as overall predictors of the percent lean mass (model R = 82.5%). Collectively, these data suggest that a complex interplay of various metabolic processes underlies the maintenance of lean mass in young healthy adults.
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Affiliation(s)
- Michael S Lustgarten
- 1Nutrition, Exercise Physiology, and Sarcopenia Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts; and 2Biostatistics Research Center, Institute for Clinical Research and Health Policy Studies, Tufts Medical Center, Boston, Massachusetts
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Kikuchi M, Ueno M, Itoh Y, Suda W, Hattori M. Uremic Toxin-Producing Gut Microbiota in Rats with Chronic Kidney Disease. Nephron Clin Pract 2016; 135:51-60. [PMID: 27701177 DOI: 10.1159/000450619] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 08/31/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND In patients with chronic kidney disease (CKD), many metabolites of gut microbiota retain in the body as uremic toxins (UTs). However, the kinds of bacteria producing UTs are rarely discussed. METHODS We analyzed UT production and the composition of gut microbiota in CKD rats and cecectomized rats. AST-120, a spherical carbon adsorbent, was administrated to evaluate how the precursors of UT affect gut microbiota. Serum and urine levels of UTs were quantified by liquid chromatography/electrospray ionization-tandem mass spectrometry. Gut microbiota were analyzed using 454-pyrosequencing of the 16S rRNA gene. Operational taxonomic unit (OTU) clustering and UniFrac analysis were performed to compare gut microbiota among the groups. RESULTS Serum and urine levels of indoxyl sulfate and phenyl sulfate were higher in CKD versus control rats (p < 0.05). AST-120 administration decreased UT production (p < 0.01) and changed overall gut microbiota composition in CKD rats. UT urinary excretion and gut microbiota composition changed in cecectomized rats, with the relative abundance of Clostridia- and Bacteroidia-affiliated species being significantly reduced (p < 0.01). We identified candidate indole- and phenol-producing intestinal microbiota, 3 Clostridia, and 2 Bacteroidia. These OTUs have a tryptophanase/tyrosine phenol-lyase gene in the closest sequenced genome out of the OTUs declined following cecectomy. CONCLUSION Our data suggest that UT production is correlated with a subset of indigenous gut microbiota. However, UT may be induced by other non-symbiotic microbiota that are influenced by factors other than microbiota populations. The relationship between specific microbiota and UTs in patients requires further clarification.
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Affiliation(s)
- Mami Kikuchi
- Department of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Tokyo, Japan
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Zhang LS, Davies SS. Microbial metabolism of dietary components to bioactive metabolites: opportunities for new therapeutic interventions. Genome Med 2016; 8:46. [PMID: 27102537 PMCID: PMC4840492 DOI: 10.1186/s13073-016-0296-x] [Citation(s) in RCA: 345] [Impact Index Per Article: 43.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Mass spectrometry- and nuclear magnetic resonance-based metabolomic studies comparing diseased versus healthy individuals have shown that microbial metabolites are often the compounds most markedly altered in the disease state. Recent studies suggest that several of these metabolites that derive from microbial transformation of dietary components have significant effects on physiological processes such as gut and immune homeostasis, energy metabolism, vascular function, and neurological behavior. Here, we review several of the most intriguing diet-dependent metabolites that may impact host physiology and may therefore be appropriate targets for therapeutic interventions, such as short-chain fatty acids, trimethylamine N-oxide, tryptophan and tyrosine derivatives, and oxidized fatty acids. Such interventions will require modulating either bacterial species or the bacterial biosynthetic enzymes required to produce these metabolites, so we briefly describe the current understanding of the bacterial and enzymatic pathways involved in their biosynthesis and summarize their molecular mechanisms of action. We then discuss in more detail the impact of these metabolites on health and disease, and review current strategies to modulate levels of these metabolites to promote human health. We also suggest future studies that are needed to realize the full therapeutic potential of targeting the gut microbiota.
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Affiliation(s)
- Linda S Zhang
- Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA
| | - Sean S Davies
- Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA. .,Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA. .,Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, 37232, USA.
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Velenosi TJ, Hennop A, Feere DA, Tieu A, Kucey AS, Kyriacou P, McCuaig LE, Nevison SE, Kerr MA, Urquhart BL. Untargeted plasma and tissue metabolomics in rats with chronic kidney disease given AST-120. Sci Rep 2016; 6:22526. [PMID: 26932318 PMCID: PMC4773761 DOI: 10.1038/srep22526] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 02/15/2016] [Indexed: 12/26/2022] Open
Abstract
Chronic kidney disease (CKD) results in the accumulation of metabolic waste products that are normally cleared by the kidney, known as uremia. Many of these waste products are from bacteria metabolites in the gut. Accumulation of uremic toxins in plasma and tissue, as well as the gut-plasma-tissue metabolic axis are important for understanding pathophysiological mechanisms of comorbidities in CKD. In this study, an untargeted metabolomics approach was used to determine uremic toxin accumulation in plasma, liver, heart and kidney tissue in rats with adenine-induced CKD. Rats with CKD were also given AST-120, a spherical carbon adsorbent, to assess metabolic changes in plasma and tissues with the removal of gut-derived uremic toxins. AST-120 decreased >55% of metabolites that were increased in plasma, liver and heart tissue of rats with CKD. CKD was primarily defined by 8 gut-derived uremic toxins, which were significantly increased in plasma and all tissues. These metabolites were derived from aromatic amino acids and soy protein including: indoxyl sulfate, p-cresyl sulfate, hippuric acid, phenyl sulfate, pyrocatechol sulfate, 4-ethylphenyl sulfate, p-cresol glucuronide and equol 7-glucuronide. Our results highlight the importance of diet and gut-derived metabolites in the accumulation of uremic toxins and define the gut-plasma-tissue metabolic axis in CKD.
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Affiliation(s)
- Thomas J Velenosi
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Anzel Hennop
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - David A Feere
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Alvin Tieu
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Andrew S Kucey
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Polydoros Kyriacou
- Department of Chemistry, The University of Western Ontario, London, ON, Canada
| | - Laura E McCuaig
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Stephanie E Nevison
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Michael A Kerr
- Department of Chemistry, The University of Western Ontario, London, ON, Canada
| | - Bradley L Urquhart
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.,Lawson Health Research Institute, London, Ontario, Canada.,Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
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Ito S, Osaka M, Edamatsu T, Itoh Y, Yoshida M. Crucial Role of the Aryl Hydrocarbon Receptor (AhR) in Indoxyl Sulfate-Induced Vascular Inflammation. J Atheroscler Thromb 2016; 23:960-75. [PMID: 26860885 DOI: 10.5551/jat.34462] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
AIM The aryl hydrocarbon receptor (AhR), a ligand-inducible transcription factor mediating toxic effects of dioxins and uremic toxins, has recently emerged as a pathophysiological regulator of immune-inflammatory conditions. Indoxyl sulfate, a uremic toxin, is associated with cardiovascular disease in patients with chronic kidney disease and has been shown to be a ligand for AhR. The aim of this study was to investigate the potential role of AhR in indoxyl sulfate-induced leukocyte-endothelial interactions. METHODS Endothelial cell-specific AhR knockout (eAhR KO) mice were produced by crossing AhR floxed mice with Tie2 Cre mice. Indoxyl sulfate was administered for 2 weeks, followed by injection of TNF-α. Leukocyte recruitment to the femoral artery was assessed by intravital microscopy. Vascular endothelial cells were transfected with siRNA specific to AhR (siAhR) and treated with indoxyl sulfate, followed by stimulation with TNF-α. RESULTS Indoxyl sulfate dramatically enhanced TNF-α-induced leukocyte recruitment to the vascular wall in control animals but not in eAhR KO mice. In endothelial cells, siAhR significantly reduced indoxyl sulfate-enhanced leukocyte adhesion as well as E-selectin expression, whereas the activation of JNK and nuclear factor-κB was not affected. A luciferase assay revealed that the region between -153 and -146 bps in the E-selectin promoter was responsible for indoxyl sulfate activity via AhR. Mutational analysis of this region revealed that activator protein-1 (AP-1) is responsible for indoxyl sulfate-triggered E-selectin expression via AhR. CONCLUSION AhR mediates indoxyl sulfate-enhanced leukocyte-endothelial interactions through AP-1 transcriptional activity, which may constitute a new mechanism of vascular inflammation in patients with renal disease.
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Affiliation(s)
- Shunsuke Ito
- Life Science and Bioethics, Department of International Health Development, Tokyo Medical and Dental University
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39
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Abstract
BACKGROUND Colon microbes produce a large number of organic compounds that are foreign to mammalian cell metabolism. SUMMARY Some of the compounds made by microbes are absorbed in the colon and then normally excreted by the kidneys. Accumulation of these compounds in the plasma as uremic solutes may contribute to illness in patients whose kidneys have failed. Mass spectrometry is expanding our knowledge of the chemical identity of the colon-derived uremic solutes, and DNA sequencing technologies are providing new knowledge of the microbes and metabolic pathways by which they are made. Because they are made in an isolated compartment by microbes, their production may prove simpler to suppress than the production of other uremic solutes. KEY MESSAGES To the extent that they are toxic, suppressing their production could improve the health of renal failure patients without the need for more intensive or prolonged dialysis.
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Affiliation(s)
- Hisae Tanaka
- Health Evaluation and Promotion Center, Tokai University Hospital, Isehara, Kanagawa, Japan
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40
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Asai H, Hirata J, Hirano A, Hirai K, Seki S, Watanabe-Akanuma M. Activation of aryl hydrocarbon receptor mediates suppression of hypoxia-inducible factor-dependent erythropoietin expression by indoxyl sulfate. Am J Physiol Cell Physiol 2015; 310:C142-50. [PMID: 26561638 DOI: 10.1152/ajpcell.00172.2015] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 11/09/2015] [Indexed: 01/01/2023]
Abstract
Indoxyl sulfate (IS) is a representative uremic toxin that accumulates in the blood of patients with chronic kidney disease (CKD). In addition to the involvement in the progression of CKD, a recent report indicates that IS suppresses hypoxia-inducible factor (HIF)-dependent erythropoietin (EPO) production, suggesting that IS may also contribute to the progression of renal anemia. In this report, we provide evidence that aryl hydrocarbon receptor (AhR) mediates IS-induced suppression of HIF activation and subsequent EPO production. In HepG2 cells, IS at concentrations similar to the blood levels in CKD patients suppressed hypoxia- or cobalt chloride-induced EPO mRNA expression and transcriptional activation of HIF. IS also induced AhR activation, and AhR blockade resulted in abolishment of IS-induced suppression of HIF activation. The HIF transcription factor is a heterodimeric complex composed of HIF-α subunits (HIF-1α and HIF-2α) and AhR nuclear translocator (ARNT). IS suppressed nuclear accumulation of the HIF-α-ARNT complex accompanied by an increase of the AhR-ARNT complex in the nucleus, implying the involvement of interactions among AhR, HIF-α, and ARNT in the suppression mechanism. In rats, oral administration of indole, a metabolic precursor of IS, inhibited bleeding-induced elevation of renal EPO mRNA expression and plasma EPO concentration and strongly induced AhR activation in the liver and renal cortex tissues. Collectively, this study is the first to elucidate the detailed mechanism by which AhR plays an indispensable role in the suppression of HIF activation by IS. Hence, IS-induced activation of AhR may be a potential therapeutic target for treating renal anemia.
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Affiliation(s)
- Hirobumi Asai
- Safety Research Center, Kureha Corporation, Tokyo, Japan
| | - Junya Hirata
- Safety Research Center, Kureha Corporation, Tokyo, Japan
| | - Ayumi Hirano
- Safety Research Center, Kureha Corporation, Tokyo, Japan
| | - Kazuya Hirai
- Safety Research Center, Kureha Corporation, Tokyo, Japan
| | - Sayaka Seki
- Safety Research Center, Kureha Corporation, Tokyo, Japan
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41
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Za'abi MA, Ali BH, ALOthman ZA, Ali I. Analyses of acute kidney injury biomarkers by ultra-high performance liquid chromatography with mass spectrometry. J Sep Sci 2015; 39:69-82. [DOI: 10.1002/jssc.201500982] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 09/17/2015] [Accepted: 09/18/2015] [Indexed: 12/21/2022]
Affiliation(s)
- Mohammed Al Za'abi
- Department of Pharmacology and Clinical Pharmacy, College of Medicine and Health, Sciences; Sultan Qaboos University; Muscat Sultanate of Oman
| | - Badreldin H. Ali
- Department of Pharmacology and Clinical Pharmacy, College of Medicine and Health, Sciences; Sultan Qaboos University; Muscat Sultanate of Oman
| | - Zeid A. ALOthman
- Department of Chemistry, College of Science; King Saud University; Riyadh Kingdom of Saudi Arabia
| | - Imran Ali
- Department of Chemistry; Jamia Millia Islamia (Central University); New Delhi India
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Vanholder RC, Eloot S, Glorieux GLRL. Future Avenues to Decrease Uremic Toxin Concentration. Am J Kidney Dis 2015; 67:664-76. [PMID: 26500179 DOI: 10.1053/j.ajkd.2015.08.029] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 08/19/2015] [Indexed: 01/13/2023]
Abstract
In this article, we review approaches for decreasing uremic solute concentrations in chronic kidney disease and in particular, in end-stage renal disease (ESRD). The rationale to do so is the straightforward relation between concentration and biological (toxic) effect for most toxins. The first section is devoted to extracorporeal strategies (kidney replacement therapy). In the context of high-flux hemodialysis and hemodiafiltration, we discuss increasing dialyzer blood and dialysate flows, frequent and/or extended dialysis, adsorption, bioartificial kidney, and changing physical conditions within the dialyzer (especially for protein-bound toxins). The next section focuses on the intestinal generation of uremic toxins, which in return is stimulated by uremic conditions. Therapeutic options are probiotics, prebiotics, synbiotics, and intestinal sorbents. Current data are conflicting, and these issues need further study before useful therapeutic concepts are developed. The following section is devoted to preservation of (residual) kidney function. Although many therapeutic options may overlap with therapies provided before ESRD, we focus on specific aspects of ESRD treatment, such as the risks of too-strict blood pressure and glycemic regulation and hemodynamic changes during dialysis. Finally, some recommendations are given on how research might be organized with regard to uremic toxins and their effects, removal, and impact on outcomes of uremic patients.
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Affiliation(s)
| | - Sunny Eloot
- Nephrology Department, University Hospital, Gent, Belgium
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43
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Hirata J, Hirai K, Asai H, Matsumoto C, Inada M, Miyaura C, Yamato H, Watanabe-Akanuma M. Indoxyl sulfate exacerbates low bone turnover induced by parathyroidectomy in young adult rats. Bone 2015; 79:252-8. [PMID: 26112820 DOI: 10.1016/j.bone.2015.06.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 05/29/2015] [Accepted: 06/16/2015] [Indexed: 11/17/2022]
Abstract
Low-turnover bone disease is one of the bone abnormalities observed in patients with chronic kidney disease (CKD) and is recognized to be associated with low serum parathyroid hormone (PTH) level and skeletal resistance to PTH. Indoxyl sulfate (IS) is a representative uremic toxin that accumulates in the blood as renal dysfunction progresses in CKD patients. A recent in vitro study using an osteoblastic cell culture system suggests that IS has an important role in the pathogenesis of low bone turnover through induction of skeletal resistance to PTH. However, the effects of IS on the progression of low bone turnover have not been elucidated. In the present study, we produced rats with low bone turnover by performing parathyroidectomy (PTX) and fed these rats a diet containing indole, a precursor of IS, to elevate blood IS level from indole metabolism. Bone metabolism was evaluated by measuring histomorphometric parameters of secondary spongiosa of the femur. Histomorphometric analyses revealed significant decreases in both bone formation-related parameters and bone resorption-related parameters in PTX rats. In indole-treated PTX rats, further decreases in bone formation-related parameters were observed. In addition, serum alkaline phosphatase activity, a bone formation marker, and bone mineral density of the tibia tended to decrease in indole-treated PTX rats. These findings strongly suggest that IS exacerbates low bone turnover through inhibition of bone formation by mechanisms unrelated to skeletal resistance to PTH.
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Affiliation(s)
- Junya Hirata
- Safety Research Center, Kureha Corporation, Tokyo 169-8503, Japan; Cooperative Major in Advanced Health Science, Tokyo University of Agriculture and Technology, Tokyo 184-8588, Japan.
| | - Kazuya Hirai
- Safety Research Center, Kureha Corporation, Tokyo 169-8503, Japan
| | - Hirobumi Asai
- Safety Research Center, Kureha Corporation, Tokyo 169-8503, Japan
| | - Chiho Matsumoto
- Cooperative Major in Advanced Health Science, Tokyo University of Agriculture and Technology, Tokyo 184-8588, Japan
| | - Masaki Inada
- Cooperative Major in Advanced Health Science, Tokyo University of Agriculture and Technology, Tokyo 184-8588, Japan
| | - Chisato Miyaura
- Cooperative Major in Advanced Health Science, Tokyo University of Agriculture and Technology, Tokyo 184-8588, Japan
| | - Hideyuki Yamato
- Safety Research Center, Kureha Corporation, Tokyo 169-8503, Japan
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Griffiths K, Hou R, Wang H, Zhang Z, Zhang L, Zhang T, Watson DG, Burchmore RJS, Loeffler IK, Kennedy MW. Prolonged transition time between colostrum and mature milk in a bear, the giant panda, Ailuropoda melanoleuca. ROYAL SOCIETY OPEN SCIENCE 2015; 2:150395. [PMID: 26587250 PMCID: PMC4632522 DOI: 10.1098/rsos.150395] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 09/21/2015] [Indexed: 06/05/2023]
Abstract
Bears produce the most altricial neonates of any placental mammal. We hypothesized that the transition from colostrum to mature milk in bears reflects a temporal and biochemical adaptation for altricial development and immune protection. Comparison of bear milks with milks of other eutherians yielded distinctive protein profiles. Proteomic and metabolomic analysis of serial milk samples collected from six giant pandas showed a prolonged transition from colostrum to main-phase lactation over approximately 30 days. Particularly striking are the persistence or sequential appearance of adaptive and innate immune factors. The endurance of immunoglobulin G suggests an unusual duration of trans-intestinal absorption of maternal antibodies, and is potentially relevant to the underdeveloped lymphoid system of giant panda neonates. Levels of certain milk oligosaccharides known to exert anti-microbial activities and/or that are conducive to the development of neonatal gut microbiomes underwent an almost complete changeover around days 20-30 postpartum, coincident with the maturation of the protein profile. A potential metabolic marker of starvation was detected, the prominence of which may reflect the natural postpartum period of anorexia in giant panda mothers. Early lactation in giant pandas, and possibly in other ursids, appears to be adapted for the unique requirements of unusually altricial eutherian neonates.
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Affiliation(s)
- Kate Griffiths
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Graham err Building, Glasgow, G12 8QQ, UK
| | - Rong Hou
- The Sichuan Key Laboratory for Conservation Biology on Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, 1375 Panda Road, Northern Suburb, Chengdu, Sichuan Province 610081, People’s Republic of China
| | - Hairui Wang
- The Sichuan Key Laboratory for Conservation Biology on Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, 1375 Panda Road, Northern Suburb, Chengdu, Sichuan Province 610081, People’s Republic of China
| | - Zhihe Zhang
- The Sichuan Key Laboratory for Conservation Biology on Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, 1375 Panda Road, Northern Suburb, Chengdu, Sichuan Province 610081, People’s Republic of China
| | - Liang Zhang
- The Sichuan Key Laboratory for Conservation Biology on Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, 1375 Panda Road, Northern Suburb, Chengdu, Sichuan Province 610081, People’s Republic of China
| | - Tong Zhang
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, UK
| | - David G. Watson
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, UK
| | - Richard J. S. Burchmore
- Institute of Infection, Immunity and Inflammation and Glasgow Polyomics, College of Medical, Veterinary and Life Sciences, University of Glasgow, Garscube Campus, Glasgow, G12 1QH, UK
| | - I. Kati Loeffler
- The Sichuan Key Laboratory for Conservation Biology on Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, 1375 Panda Road, Northern Suburb, Chengdu, Sichuan Province 610081, People’s Republic of China
| | - Malcolm W. Kennedy
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Graham err Building, Glasgow, G12 8QQ, UK
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Vaziri ND, Zhao YY, Pahl MV. Altered intestinal microbial flora and impaired epithelial barrier structure and function in CKD: the nature, mechanisms, consequences and potential treatment. Nephrol Dial Transplant 2015; 31:737-46. [PMID: 25883197 DOI: 10.1093/ndt/gfv095] [Citation(s) in RCA: 246] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 03/16/2015] [Indexed: 02/06/2023] Open
Abstract
Chronic kidney disease (CKD) results in systemic inflammation and oxidative stress which play a central role in CKD progression and its adverse consequences. Although many of the causes and consequences of oxidative stress and inflammation in CKD have been extensively explored, little attention had been paid to the intestine and its microbial flora as a potential source of these problems. Our recent studies have revealed significant disruption of the colonic, ileal, jejunal and gastric epithelial tight junction in different models of CKD in rats. Moreover, the disruption of the epithelial barrier structure and function found in uremic animals was replicated in cultured human colonocytes exposed to uremic human plasma in vitro We have further found significant changes in the composition and function of colonic bacterial flora in humans and animals with advanced CKD. Together, uremia-induced impairment of the intestinal epithelial barrier structure and function and changes in composition of the gut microbiome contribute to the systemic inflammation and uremic toxicity by accommodating the translocation of endotoxin, microbial fragments and other noxious luminal products in the circulation. In addition, colonic bacteria are the main source of several well-known pro-inflammatory uremic toxins such as indoxyl sulfate, p-cresol sulfate, trimethylamine-N-oxide and many as-yet unidentified retained compounds in end-stage renal disease patients. This review is intended to provide an overview of the effects of CKD on the gut microbiome and intestinal epithelial barrier structure and their role in the pathogenesis of systemic inflammation and uremic toxicity. In addition, potential interventions aimed at mitigating these abnormalities are briefly discussed.
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Affiliation(s)
- Nosratola D Vaziri
- Division of Nephrology and Hypertension, Department of Medicine, University of California, Irvine Medical Center, Orange, CA, USA
| | - Ying-Yong Zhao
- Division of Nephrology and Hypertension, Department of Medicine, University of California, Irvine Medical Center, Orange, CA, USA
| | - Madeleine V Pahl
- Division of Nephrology and Hypertension, Department of Medicine, University of California, Irvine Medical Center, Orange, CA, USA
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46
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Affiliation(s)
- Madeleine V. Pahl
- Division of Nephrology and Hypertension; Department of Medicine; University of California; Irvine Orange California
| | - Nosratola D. Vaziri
- Division of Nephrology and Hypertension; Department of Medicine; University of California; Irvine Orange California
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47
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Lekawanvijit S, Krum H. Cardiorenal Syndrome: Role of Protein-Bound Uremic Toxins. J Ren Nutr 2015; 25:149-54. [DOI: 10.1053/j.jrn.2014.10.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 10/29/2014] [Indexed: 12/21/2022] Open
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Vanholder R, Glorieux G. The intestine and the kidneys: a bad marriage can be hazardous. Clin Kidney J 2015; 8:168-79. [PMID: 25815173 PMCID: PMC4370304 DOI: 10.1093/ckj/sfv004] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 01/13/2015] [Indexed: 12/20/2022] Open
Abstract
The concept that the intestine and chronic kidney disease influence each other, emerged only recently. The problem is multifaceted and bidirectional. On one hand, the composition of the intestinal microbiota impacts uraemic retention solute production, resulting in the generation of essentially protein-bound uraemic toxins with strong biological impact such as vascular damage and progression of kidney failure. On the other hand, the uraemic status affects the composition of intestinal microbiota, the generation of uraemic retention solutes and their precursors and causes disturbances in the protective epithelial barrier of the intestine and the translocation of intestinal microbiota into the body. All these elements together contribute to the disruption of the metabolic equilibrium and homeostasis typical to uraemia. Several measures with putative impact on intestinal status have recently been tested for their influence on the generation or concentration of uraemic toxins. These include dietary measures, prebiotics, probiotics, synbiotics and intestinal sorbents. Unfortunately, the quality and the evidence base of many of these studies are debatable, especially in uraemia, and often results within one study or among studies are contradictory. Nevertheless, intestinal uraemic metabolite generation remains an interesting target to obtain in the future as an alternative or additive to dialysis to decrease uraemic toxin generation. In the present review, we aim to summarize (i) the role of the intestine in uraemia by producing uraemic toxins and by generating pathophysiologically relevant changes, (ii) the role of uraemia in modifying intestinal physiology and (iii) the therapeutic options that could help to modify these effects and the studies that have assessed the impact of these therapies.
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Affiliation(s)
- Raymond Vanholder
- Nephrology Section, 0K12 , University Hospital , Ghent B9000 , Belgium
| | - Griet Glorieux
- Nephrology Section, 0K12 , University Hospital , Ghent B9000 , Belgium
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A pharmaco-metabonomic study on chronic kidney disease and therapeutic effect of ergone by UPLC-QTOF/HDMS. PLoS One 2014; 9:e115467. [PMID: 25535749 PMCID: PMC4275224 DOI: 10.1371/journal.pone.0115467] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 11/23/2014] [Indexed: 11/25/2022] Open
Abstract
Chronic kidney disease (CKD) is an important public health problem. Ergone has been proved to prevent the progression of CKD. UPLC-QTOF/HDMS was employed for metabolic profiling of adenine-induced CKD and to investigate the nephroprotective effects of ergone. Pharmacology parameters including blood biochemistry, histopathological evaluation and Western blot analysis were performed concurrently. The UPLC-MS data were analyzed by partial least squares-discriminate analysis, correlation analysis, heatmap analysis and mapped to KEGG pathways. Blood and serum biochemistry were observed to be significantly different in the CKD group than in the control group. In conjunction with biochemistry, histopathology and protein expression results, identified metabolites indicated perturbations in fatty acid metabolism, purine metabolism and amino acid metabolism as changes associated with adenine-induced CKD and the interventions of ergone. Upregulated expression of TGF-β1, ED-1, CTGF, bFGF and collagen I was observed in the CKD group. However, downregulated expression of these proteins was observed after oral administration of ergone. These results suggest that expression changes in these proteins had implications for fatty acid metabolism, purine metabolism and amino acid metabolism in the development of CKD and that ergone treatment could delay the development of CKD by normalizing or blocking abnormal changes in biomarker metabolites and protein expression in the CKD group.
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50
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Vanholder R, Boelaert J, Glorieux G, Eloot S. New methods and technologies for measuring uremic toxins and quantifying dialysis adequacy. Semin Dial 2014; 28:114-24. [PMID: 25441338 DOI: 10.1111/sdi.12331] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
This publication reviews the currently available methods to identify uremic retention solutes, to determine their biological relevance and to quantify their removal. The analytical methods for the detection of uremic solutes have improved continuously, allowing the identification of several previously unknown solutes. Progress has been accelerated by the development of comprehensive strategies such as genomics, proteomics and the latest "omics" area, metabolomics. Those methodologies will be further refined in future. Once the concentration of solutes of interest is known based on targeted analysis, their biological relevance can be studied by means of in vitro, ex vivo, or animal models, provided those are representative for the key complications of the uremic syndrome. For this to come to pass, rigid protocols should be applied, e.g., aiming at free solute concentrations conform those found in uremia. Subsequently, the decrease in concentration of relevant solutes should be pursued by nondialysis (e.g., by influencing nutritional intake or intestinal generation, using sorbents, modifying metabolism, or preserving renal function) and dialysis methods. Optimal dialysis strategies can be sought by studying solute kinetics during dialysis. Clinical studies are necessary to assess the correct impact of those optimized strategies on outcomes. Although longitudinal studies of solute concentration and surrogate outcome studies are first steps in suggesting the usefulness of a given approach, ultimately hard outcome randomized controlled trials are needed to endorse evidence-based therapeutic choices. The nonspecificity of dialysis removal is however a handicap limiting the chances to provide proof of concept that a given solute or group of solutes has definite biological impact.
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Affiliation(s)
- Raymond Vanholder
- Nephrology Section, Department of Internal Medicine, Ghent University Hospital, Gent, Belgium
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