RESUMO
Indoxyl sulfate (IS) is involved in the progression of chronic kidney disease (CKD) and in its cardiovascular complications. One of the approaches proposed to decrease IS is the administration of synbiotics. This work aimed to search for a probiotic strain capable to decrease serum IS levels and mix it with two prebiotics (inulin and fructooligosaccharide (FOS)) to produce a putative synbiotic and test it in a rat CKD model. Two groups of Sprague-Dawley rats were nephrectomized. One group (Lac) received the mixture for 16 weeks in drinking water and the other no (Nef). A control group (C) included sham-nephrectomized rats. Serum creatinine and IS concentrations were measured using high-performance liquid chromatography with diode array detector (HPLC-DAD). Optical microscopy and two-photon excitation microscopy was used to study kidney and heart samples. The Lac group, which received the synbiotic, reduced IS by 0.8% while the Nef group increased it by 38.8%. Histological analysis of kidneys showed that the Lac group increased fibrotic areas by 12% and the Nef group did it by 25%. The synbiotic did not reduce cardiac fibrosis. Therefore, the putative synbiotic showed that function reducing IS and the progression of CKD in a rat model, but no heart protection was observed.
Assuntos
Cardiopatias/terapia , Indicã/sangue , Inulina/administração & dosagem , Rim/metabolismo , Lactobacillus delbrueckii/fisiologia , Oligossacarídeos/administração & dosagem , Insuficiência Renal Crônica/terapia , Simbióticos , Toxinas Biológicas/sangue , Animais , Creatinina/sangue , Modelos Animais de Doenças , Progressão da Doença , Feminino , Fibrose , Cardiopatias/sangue , Cardiopatias/microbiologia , Cardiopatias/patologia , Rim/patologia , Miocárdio/metabolismo , Miocárdio/patologia , Ratos Sprague-Dawley , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/microbiologia , Insuficiência Renal Crônica/patologiaRESUMO
BACKGROUND: Gut dysbiosis is common in patients with chronic kidney disease (CKD) and is closely related to inflammatory processes. Some nutritional strategies, such as bioactive compounds present in curcumin, have been proposed as an option to modulate the gut microbiota and decrease the production of uremic toxins such as indoxyl sulfate (IS), p-cresyl sulfate (pCS) and indole-3 acetic acid (IAA). OBJECTIVE: To evaluate the effects of curcumin supplementation on uremic toxins plasma levels produced by gut microbiota in patients with CKD on hemodialysis (HD). METHODS: Randomized, double-blind trial in 28 patients [53.6 ± 13.4 years, fourteen men, BMI 26.7 ± 3.7 kg/m2, dialysis vintage 37.5 (12-193) months]. Fourteen patients were randomly allocated to the curcumin group and received 100 mL of orange juice with 12 g carrot and 2.5 g of turmeric and 14 patients to the control group who received the same juice but without turmeric three times per week after HD sessions for three months. IS, pCS, IAA plasma levels were measured by reverse-phase high-performance liquid chromatography RESULTS: After three months of supplementation, the curcumin group showed a significant decrease in pCS plasma levels [from 32.4 (22.1-45.9) to 25.2 (17.9-37.9) mg/L, p = 0.009], which did not occur in the control group. No statistical difference was observed in IS and IAA levels in both groups. CONCLUSION: The oral supplementation of curcumin for three months seems to reduce p-CS plasma levels in HD patients, suggesting a gut microbiota modulation.
Assuntos
Cresóis/sangue , Curcumina/uso terapêutico , Suplementos Nutricionais , Microbioma Gastrointestinal , Indicã/sangue , Ácidos Indolacéticos/sangue , Diálise Renal , Ésteres do Ácido Sulfúrico/sangue , Toxinas Biológicas/sangue , Uremia/sangue , Adulto , Idoso , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos PilotoRESUMO
BACKGROUND: The aim of this study was to evaluate the effect of resistant starch (RS) enriched cookies supplementation on mRNA expression of nuclear transcription factors (nuclear erythroid 2-related factor, Nrf2; nuclear factor kappa-B, NF-κB), involved with inflammation and on uremic toxins levels produced by the gut microbiota in hemodialysis (HD) patients. METHODS: A randomized, double-blind, placebo-controlled crossover study with 26 HD patients was conducted. The patients were assigned to either resistant starch enriched cookies (16 g of RS per day) or placebo cookies supplementation during the first four weeks. After the washout period, patients were supplemented again, in the form of a crossover, for another 4 weeks. Nrf2, NF-κB, and antioxidant enzymes mRNA expression were measured by rt-PCR and protein expression by western blotting assay from isolated peripheral blood mononuclear cells (PBMC). Oxidative stress and inflammatory biomarkers, as well as uremic toxins, were evaluated. Intention-to-treat analysis was performed, using the proc mixed procedure in SAS. RESULTS: In RS group, post-treatment mean mRNA Nrf2 expression was market increased from baseline values, associated with a high expression of NQO1 protein. Besides, IS plasma levels were reduced in the RS group. No significant difference was observed in the placebo group. CONCLUSION: Our results suggested that resistant starch enriched cookies may be a good nutritional strategy to reduce indoxyl sulfate levels derived from the gut microbiota and also attenuate the inflammation in hemodialysis patients.
Assuntos
Inflamação/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Diálise Renal , Amido Resistente , Administração Oral , Biomarcadores/sangue , Estudos Cross-Over , Suplementos Nutricionais , Método Duplo-Cego , Microbioma Gastrointestinal/efeitos dos fármacos , Humanos , Indicã/sangue , Pessoa de Meia-Idade , Fator 2 Relacionado a NF-E2/metabolismo , NF-kappa B/metabolismo , Amido Resistente/administração & dosagem , Amido Resistente/farmacologiaRESUMO
OBJECTIVE: The aim of this study is to evaluate the association between bowel habits and microbial-derived uremic toxins p-cresyl sulfate (PCS) and indoxyl sulfate (IS) in patients with non-dialysis-dependent chronic kidney disease (NDD-CKD). DESIGN AND METHODS: This is a cross-sectional analysis including 43 nondiabetic NDD-CKD patients (58% men; 59.0 ± 13.5 years; estimated glomerular filtration rate, 21.3 ± 7.9 mL/min/1.73 m2). Bowel habit was assessed by the Bristol Stool Scale (BSS <3, characterized by hard consistency of stools and/or low frequency of evacuation and BSS ≥3, representing a more regular bowel habit) and by the Rome III criteria. PCS and IS (serum, free and total; urinary, total) were determined by high-performance liquid chromatography. Dietary intake was assessed by the 3-day food records. RESULTS: The frequency of constipation assessed by BSS and Rome III criteria was 33% (n = 14/43) and 35% (n = 15/43), respectively. The BSS <3 exhibited higher PCS, independent of renal function and dietary protein-fiber ratio (ß [95% confidence interval {CI}]: serum, total PCS = 1.54 [1.06-2.23], P = .02; serum free PCS = 1.40 [1.00-1.97], P = .05; urinary PCS = 1.78 [1.10-2.90], P < .02). According to the Rome III criteria, a tendency for a higher serum total PCS (ß [95% CI]: 1.39 [0.95-2.03 µmol/L], P = .09) and a significantly higher urinary PCS (ß [95% CI]: 1.80 [1.11-2.94 µmol/24 h], P = .02) was found in constipated participants. No effect of a compromised bowel habit (Rome III criteria or BSS) was found on IS. CONCLUSION: Constipation may lead to production of PCS in nondiabetic NDD-CKD patients.
Assuntos
Constipação Intestinal/complicações , Cresóis/sangue , Cresóis/urina , Indicã/sangue , Indicã/urina , Insuficiência Renal Crônica/complicações , Ésteres do Ácido Sulfúrico/sangue , Ésteres do Ácido Sulfúrico/urina , Constipação Intestinal/sangue , Constipação Intestinal/urina , Estudos Transversais , Defecação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/urinaRESUMO
ABSTRACT One of the mechanisms proposed for chronic kidney disease (CKD)-related cognitive impairment is the accumulation of uremic toxins due to the deterioration of the renal clearance function. Cognition can be categorized into five major domains according to its information processing functions: memory, attention, language, visual-spatial, and executive. We performed a review using the terms 'uric acid', 'indoxyl sulfate', 'p-cresyl sulfate', 'homocysteine', 'interleukins' and 'parathyroid hormone'. These are the compounds that were found to be strongly associated with cognitive impairment in CKD in the literature. The 26 selected articles point towards an association between higher levels of uric acid, homocysteine, and interleukin 6 with lower cognitive performance in executive, attentional, and memory domains. We also reviewed the hemodialysis effects on cognition. Hemodialysis seems to contribute to an amelioration of CKD-related encephalopathic dysfunction, although this improvement occurs more in some cognitive domains than in others.
RESUMO Um dos mecanismos propostos para explicar o comprometimento cognitivo relacionado à doença renal crônica (DRC) é o acúmulo de toxinas urêmicas devido à deterioração da função de depuração renal. A cognição pode ser categorizada em cinco domínios principais de acordo com suas funções de processamento de informações: memória, atenção, linguagem, visual-espacial e executiva. Realizamos uma revisão usando os termos "ácido úrico", "indoxil sulfato", "p-cresil sulfato", "homocisteína", "interleucinas" e "paratormônio". Estes são os compostos que se mostraram fortemente associados ao comprometimento cognitivo na DRC na literatura. Os 26 artigos selecionados apontam para uma associação entre níveis mais elevados de ácido úrico, homocisteína e interleucina-6 com menor desempenho cognitivo nos domínios executivo, atenção e de memória. Também revisamos os efeitos da hemodiálise na cognição. A hemodiálise parece contribuir para uma melhoria da disfunção encefalopática relacionada à DRC, embora essa melhora ocorra mais em alguns domínios cognitivos do que em outros.
Assuntos
Humanos , Toxinas Biológicas/efeitos adversos , Uremia/complicações , Insuficiência Renal Crônica/complicações , Disfunção Cognitiva/etiologia , Hormônio Paratireóideo/efeitos adversos , Ésteres do Ácido Sulfúrico/efeitos adversos , Ésteres do Ácido Sulfúrico/sangue , Ácido Úrico/efeitos adversos , Ácido Úrico/sangue , Diálise Renal/efeitos adversos , Interleucina-6/efeitos adversos , Cresóis/efeitos adversos , Cresóis/sangue , Interleucina-1beta/efeitos adversos , Interleucina-1beta/sangue , Homocisteína/efeitos adversos , Homocisteína/sangue , Indicã/efeitos adversos , Indicã/sangueRESUMO
BACKGROUND AND OBJECTIVES: Current hemodialysis techniques fail to efficiently remove the protein-bound uremic toxins p-cresyl sulfate and indoxyl sulfate due to their high degree of albumin binding. Ibuprofen, which shares the same primary albumin binding site with p-cresyl sulfate and indoxyl sulfate, can be infused during hemodialysis to displace these toxins, thereby augmenting their removal. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We infused 800 mg ibuprofen into the arterial bloodline between minutes 21 and 40 of a conventional 4-hour high-flux hemodialysis treatment. We measured arterial, venous, and dialysate outlet concentrations of indoxyl sulfate, p-cresyl sulfate, tryptophan, ibuprofen, urea, and creatinine before, during, and after the ibuprofen infusion. We report clearances of p-cresyl sulfate and indoxyl sulfate before and during ibuprofen infusion and dialysate concentrations of protein-bound uremic toxins normalized to each patient's average preinfusion concentrations. RESULTS: We studied 18 patients on maintenance hemodialysis: age 36±11 years old, ten women, and mean vintage of 37±37 months. Compared with during the preinfusion period, the median (interquartile range) clearances of indoxyl sulfate and p-cresyl sulfate increased during ibuprofen infusion from 6.0 (6.5) to 20.2 (27.1) ml/min and from 4.4 (6.7) to 14.9 (27.1) ml/min (each P<0.001), respectively. Relative median (interquartile range) protein-bound uremic toxin dialysate outlet levels increased from preinfusion 1.0 (reference) to 2.4 (1.2) for indoxyl sulfate and to 2.4 (1.0) for p-cresyl sulfate (each P<0.001). Although median serum post- and predialyzer levels in the preinfusion period were similar, infusion led to a marked drop in serum postdialyzer levels for both indoxyl sulfate and p-cresyl sulfate (-1.0 and -0.3 mg/dl, respectively; each P<0.001). The removal of the nonprotein-bound solutes creatinine and urea was not increased by the ibuprofen infusion. CONCLUSIONS: Infusion of ibuprofen into the arterial bloodline during hemodialysis significantly increases the dialytic removal of indoxyl sulfate and p-cresyl sulfate and thereby, leads to greater reduction in their serum levels.
Assuntos
Cresóis/sangue , Ibuprofeno/administração & dosagem , Indicã/sangue , Diálise Renal , Albumina Sérica Humana/metabolismo , Ésteres do Ácido Sulfúrico/sangue , Uremia/terapia , Adulto , Ligação Competitiva , Feminino , Humanos , Ibuprofeno/efeitos adversos , Ibuprofeno/sangue , Infusões Intra-Arteriais , Masculino , Pessoa de Meia-Idade , Ligação Proteica , Diálise Renal/efeitos adversos , Fatores de Tempo , Resultado do Tratamento , Uremia/sangue , Uremia/diagnósticoRESUMO
One of the mechanisms proposed for chronic kidney disease (CKD)-related cognitive impairment is the accumulation of uremic toxins due to the deterioration of the renal clearance function. Cognition can be categorized into five major domains according to its information processing functions: memory, attention, language, visual-spatial, and executive. We performed a review using the terms 'uric acid', 'indoxyl sulfate', 'p-cresyl sulfate', 'homocysteine', 'interleukins' and 'parathyroid hormone'. These are the compounds that were found to be strongly associated with cognitive impairment in CKD in the literature. The 26 selected articles point towards an association between higher levels of uric acid, homocysteine, and interleukin 6 with lower cognitive performance in executive, attentional, and memory domains. We also reviewed the hemodialysis effects on cognition. Hemodialysis seems to contribute to an amelioration of CKD-related encephalopathic dysfunction, although this improvement occurs more in some cognitive domains than in others.
Assuntos
Disfunção Cognitiva/etiologia , Insuficiência Renal Crônica/complicações , Toxinas Biológicas/efeitos adversos , Uremia/complicações , Cresóis/efeitos adversos , Cresóis/sangue , Homocisteína/efeitos adversos , Homocisteína/sangue , Humanos , Indicã/efeitos adversos , Indicã/sangue , Interleucina-1beta/efeitos adversos , Interleucina-1beta/sangue , Interleucina-6/efeitos adversos , Hormônio Paratireóideo/efeitos adversos , Diálise Renal/efeitos adversos , Ésteres do Ácido Sulfúrico/efeitos adversos , Ésteres do Ácido Sulfúrico/sangue , Ácido Úrico/efeitos adversos , Ácido Úrico/sangueRESUMO
Uremic toxin (UT) retention in chronic kidney disease (CKD) affects biological systems. We aimed to identify the associations between UT, inflammatory biomarkers and biomarkers of the uremic cardiovascular response (BUCVR) and their impact on cardiovascular status as well as their roles as predictors of outcome in CKD patients. CKD patients stages 3, 4 and 5 (n = 67) were recruited and UT (indoxyl sulfate/IS, p-cresil sulfate/pCS and indole-3-acetic acid/IAA); inflammatory biomarkers [Interleukin-6 (IL-6), high sensitivity C reactive protein (hsCRP), monocyte chemoattractant protein-1 (MCP-1), soluble vascular adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1 (sICAM-1) and soluble Fas (sFas)] and BUCVRs [soluble CD36 (sCD36), soluble receptor for advanced glycation end products (sRAGE), fractalkine] was measured. Patients were followed for 5.2 years and all causes of death was used as the primary outcome. Artery segments collected at the moment of transplantation were used for the immunohistochemistry analysis in a separate cohort. Estimated glomerular filtration rate (eGFR), circulating UT, plasma biomarkers of systemic and vascular inflammation and BUCVR were strongly interrelated. Patients with plaque presented higher signs of UT-induced inflammation and arteries from CKD patients presented higher fractalkine receptor (CX3CR1) tissue expression. Circulating IS (p = 0.03), pCS (p = 0.007), IL-6 (p = 0.026), sFas (p = 0.001), sCD36 (p = 0.01) and fractalkine (p = 0.02) were independent predictors of total mortality risk in CKD patients. Our results reinforce the important role of uremic toxicity in the pathogenesis of cardiovascular disease (CVD) in CKD patients through an inflammatory pathway.
Assuntos
Doenças Cardiovasculares/metabolismo , Cresóis/sangue , Indicã/sangue , Ácidos Indolacéticos/sangue , Inflamação/metabolismo , Insuficiência Renal Crônica/metabolismo , Ésteres do Ácido Sulfúrico/sangue , Toxinas Biológicas/sangue , Uremia/metabolismo , Adulto , Idoso , Biomarcadores/metabolismo , Antígenos CD36/metabolismo , Doenças Cardiovasculares/fisiopatologia , Citocinas/metabolismo , Feminino , Taxa de Filtração Glomerular , Humanos , Inflamação/fisiopatologia , Masculino , Pessoa de Meia-Idade , Artéria Renal/metabolismo , Insuficiência Renal Crônica/fisiopatologia , Uremia/fisiopatologiaRESUMO
In patients with CKD, not only renal but also, nonrenal clearance of drugs is altered. Uremic toxins could modify the expression and/or activity of drug transporters in the liver. We tested whether the uremic toxin indoxyl sulfate (IS), an endogenous ligand of the transcription factor aryl hydrocarbon receptor, could change the expression of the following liver transporters involved in drug clearance: SLC10A1, SLC22A1, SLC22A7, SLC47A1, SLCO1B1, SLCO1B3, SLCO2B1, ABCB1, ABCB11, ABCC2, ABCC3, ABCC4, ABCC6, and ABCG2 We showed that IS increases the expression and activity of the efflux transporter P-glycoprotein (P-gp) encoded by ABCB1 in human hepatoma cells (HepG2) without modifying the expression of the other transporters. This effect depended on the aryl hydrocarbon receptor pathway. Presence of human albumin at physiologic concentration in the culture medium did not abolish the effect of IS. In two mouse models of CKD, the decline in renal function associated with the accumulation of IS in serum and the specific upregulation of Abcb1a in the liver. Additionally, among 109 heart or kidney transplant recipients with CKD, those with higher serum levels of IS needed higher doses of cyclosporin, a P-gp substrate, to obtain the cyclosporin target blood concentration. This need associated with serum levels of IS independent of renal function. These findings suggest that increased activity of P-gp could be responsible for increased hepatic cyclosporin clearance. Altogether, these results suggest that uremic toxins, such as IS, through effects on drug transporters, may modify the nonrenal clearance of drugs in patients with CKD.
Assuntos
Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Indicã/sangue , Receptores de Hidrocarboneto Arílico/metabolismo , Insuficiência Renal Crônica/sangue , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Albuminas/farmacologia , Animais , Ciclosporina/sangue , Ciclosporina/farmacocinética , Modelos Animais de Doenças , Feminino , Expressão Gênica/efeitos dos fármacos , Transplante de Coração , Células Hep G2 , Humanos , Imunossupressores/sangue , Imunossupressores/farmacocinética , Indicã/farmacologia , Transplante de Rim , Fígado/metabolismo , Masculino , Camundongos , Pessoa de Meia-Idade , Proteína 2 Associada à Farmacorresistência Múltipla , RNA Mensageiro/metabolismo , Insuficiência Renal Crônica/fisiopatologia , Transdução de Sinais , Regulação para CimaRESUMO
Recently, the clinical and experimental evidences that support the toxic effects of indoxyl sulfate, a protein-bound uremic toxin in chronic kidney disease (CKD) patients, has been discussed. In this panorama, the authors described several in vitro and in vivo studies, suggesting that indoxyl sulfate may play a part in the pathogenesis of low turnover bone disease. However, the discussion claims the need for relevant clinical studies in CKD patients whose bone turnover biomarkers and bone histomorphometry were assessed in order to demonstrate the association between serum levels of indoxyl sulfate and bone turnover. We would like to underline the availability of this clinical data to support the concept that indoxyl sulfate may play a part in the pathogenesis of low turnover bone disease in CKD patients.