RESUMO
Diabetic kidney disease is a major cause of renal failure that urgently necessitates a breakthrough in disease management. Here we show using untargeted metabolomics that levels of phenyl sulfate, a gut microbiota-derived metabolite, increase with the progression of diabetes in rats overexpressing human uremic toxin transporter SLCO4C1 in the kidney, and are decreased in rats with limited proteinuria. In experimental models of diabetes, phenyl sulfate administration induces albuminuria and podocyte damage. In a diabetic patient cohort, phenyl sulfate levels significantly correlate with basal and predicted 2-year progression of albuminuria in patients with microalbuminuria. Inhibition of tyrosine phenol-lyase, a bacterial enzyme responsible for the synthesis of phenol from dietary tyrosine before it is metabolized into phenyl sulfate in the liver, reduces albuminuria in diabetic mice. Together, our results suggest that phenyl sulfate contributes to albuminuria and could be used as a disease marker and future therapeutic target in diabetic kidney disease.
Assuntos
Albuminúria/etiologia , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 2/complicações , Nefropatias Diabéticas/sangue , Microbioma Gastrointestinal/fisiologia , Ésteres do Ácido Sulfúrico/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Albuminúria/sangue , Albuminúria/tratamento farmacológico , Albuminúria/patologia , Animais , Animais Geneticamente Modificados , Estudos de Coortes , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/urina , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 2/sangue , Nefropatias Diabéticas/etiologia , Nefropatias Diabéticas/patologia , Cães , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Feminino , Humanos , Células Madin Darby de Rim Canino , Masculino , Metabolômica/métodos , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Transportadores de Ânions Orgânicos/genética , Podócitos/metabolismo , Podócitos/patologia , Ratos , Estreptozocina/toxicidade , Ésteres do Ácido Sulfúrico/sangue , Tirosina Fenol-Liase/antagonistas & inibidores , Tirosina Fenol-Liase/metabolismo , Adulto JovemRESUMO
Accumulation of uremic toxins, which exert deleterious effects in chronic kidney disease, is influenced by the intestinal environment; the microbiota contributes to the production of representative uremic toxins, including p-cresyl sulfate and indoxyl sulfate. Canagliflozin is a sodium-glucose cotransporter (SGLT) 2 inhibitor, and it also exerts a modest inhibitory effect on SGLT1. The inhibition of intestinal SGLT1 can influence the gastrointestinal environment. We examined the effect of canagliflozin on the accumulation of uremic toxins in chronic kidney disease using adenine-induced renal failure mice. Two-week canagliflozin (10 mg/kg po) treatment did not influence the impaired renal function; however, it significantly reduced the plasma levels of p-cresyl sulfate and indoxyl sulfate in renal failure mice (a 75% and 26% reduction, respectively, compared with the vehicle group). Additionally, canagliflozin significantly increased cecal short-chain fatty acids in the mice, suggesting the promotion of bacterial carbohydrate fermentation in the intestine. Analysis of the cecal microbiota showed that canagliflozin significantly altered microbiota composition in the renal failure mice. These results indicate that canagliflozin exerts intestinal effects that reduce the accumulation of uremic toxins including p-cresyl sulfate. Reduction of accumulated uremic toxins by canagliflozin could provide a potential therapeutic option in chronic kidney disease.
Assuntos
Canagliflozina/farmacologia , Microbioma Gastrointestinal/efeitos dos fármacos , Insuficiência Renal Crônica/tratamento farmacológico , Toxinas Biológicas/sangue , Animais , Modelos Animais de Doenças , Trato Gastrointestinal/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Insuficiência Renal Crônica/sangue , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia , Toxinas Biológicas/farmacologia , Uremia/sangue , Uremia/tratamento farmacológicoRESUMO
Gut microbiota is involved in the metabolism of uremic solutes. However, the precise influence of microbiota to the retention of uremic solutes in CKD is obscure. To clarify this, we compared adenine-induced renal failure and control mice under germ-free or specific pathogen-free (SPF) conditions, examining the metabolite profiles of plasma, feces, and urine using a capillary electrophoresis time-of-flight mass spectrometry-based approach. Mice with renal failure under germ-free conditions demonstrated significant changes in plasma metabolites. Among 183 detected solutes, plasma levels of 11 solutes, including major uremic toxins, were significantly lower in germ-free mice than in SPF mice with renal failure. These 11 solutes were considered microbiota-derived uremic solutes and included indoxyl sulfate, p-cresyl sulfate, phenyl sulfate, cholate, hippurate, dimethylglycine, γ-guanidinobutyrate, glutarate, 2-hydroxypentanoate, trimethylamine N-oxide, and phenaceturate. Metabolome profiling showed that these solutes were classified into three groups depending on their origins: completely derived from microbiota (indoxyl sulfate, p-cresyl sulfate), derived from both host and microbiota (dimethylglycine), and derived from both microbiota and dietary components (trimethylamine N-oxide). Additionally, germ-free renal failure conditions resulted in the disappearance of colonic short-chain fatty acids, decreased utilization of intestinal amino acids, and more severe renal damage compared with SPF mice with renal failure. Microbiota-derived short-chain fatty acids and efficient amino acid utilization may have a renoprotective effect, and loss of these factors may exacerbate renal damage in germ-free mice with renal failure. Thus, microbiota contributes substantially to the production of harmful uremic solutes, but conversely, growth without microbiota has harmful effects on CKD progression.
Assuntos
Injúria Renal Aguda/metabolismo , Microbioma Gastrointestinal/fisiologia , Metaboloma , Insuficiência Renal Crônica/metabolismo , Toxinas Biológicas/sangue , Uremia/metabolismo , Injúria Renal Aguda/sangue , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/urina , Adenina/toxicidade , Animais , Modelos Animais de Doenças , Progressão da Doença , Eletroforese Capilar , Ácidos Graxos Voláteis/análise , Ácidos Graxos Voláteis/metabolismo , Humanos , Rim/patologia , Espectrometria de Massas , Metabolômica/métodos , Camundongos , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/patologia , Insuficiência Renal Crônica/urina , Organismos Livres de Patógenos Específicos , Toxinas Biológicas/urina , Uremia/sangue , Uremia/urinaRESUMO
The accumulation of uremic toxins is involved in the progression of CKD. Various uremic toxins are derived from gut microbiota, and an imbalance of gut microbiota or dysbiosis is related to renal failure. However, the pathophysiologic mechanisms underlying the relationship between the gut microbiota and renal failure are still obscure. Using an adenine-induced renal failure mouse model, we evaluated the effects of the ClC-2 chloride channel activator lubiprostone (commonly used for the treatment of constipation) on CKD. Oral administration of lubiprostone (500 µg/kg per day) changed the fecal and intestinal properties in mice with renal failure. Additionally, lubiprostone treatment reduced the elevated BUN and protected against tubulointerstitial damage, renal fibrosis, and inflammation. Gut microbiome analysis of 16S rRNA genes in the renal failure mice showed that lubiprostone treatment altered their microbial composition, especially the recovery of the levels of the Lactobacillaceae family and Prevotella genus, which were significantly reduced in the renal failure mice. Furthermore, capillary electrophoresis-mass spectrometry-based metabolome analysis showed that lubiprostone treatment decreased the plasma level of uremic toxins, such as indoxyl sulfate and hippurate, which are derived from gut microbiota, and a more recently discovered uremic toxin, trans-aconitate. These results suggest that lubiprostone ameliorates the progression of CKD and the accumulation of uremic toxins by improving the gut microbiota and intestinal environment.
Assuntos
Alprostadil/análogos & derivados , Agonistas dos Canais de Cloreto/uso terapêutico , Trato Gastrointestinal/efeitos dos fármacos , Falência Renal Crônica/prevenção & controle , Microbiota/efeitos dos fármacos , Adenina , Alprostadil/farmacologia , Alprostadil/uso terapêutico , Animais , Agonistas dos Canais de Cloreto/farmacologia , Progressão da Doença , Avaliação Pré-Clínica de Medicamentos , Trato Gastrointestinal/microbiologia , Falência Renal Crônica/induzido quimicamente , Lubiprostona , Masculino , Camundongos Endogâmicos C57BL , Distribuição Aleatória , Uremia/prevenção & controleRESUMO
Gut commensal microbes shape the mucosal immune system by regulating the differentiation and expansion of several types of T cell. Clostridia, a dominant class of commensal microbe, can induce colonic regulatory T (Treg) cells, which have a central role in the suppression of inflammatory and allergic responses. However, the molecular mechanisms by which commensal microbes induce colonic Treg cells have been unclear. Here we show that a large bowel microbial fermentation product, butyrate, induces the differentiation of colonic Treg cells in mice. A comparative NMR-based metabolome analysis suggests that the luminal concentrations of short-chain fatty acids positively correlates with the number of Treg cells in the colon. Among short-chain fatty acids, butyrate induced the differentiation of Treg cells in vitro and in vivo, and ameliorated the development of colitis induced by adoptive transfer of CD4(+) CD45RB(hi) T cells in Rag1(-/-) mice. Treatment of naive T cells under the Treg-cell-polarizing conditions with butyrate enhanced histone H3 acetylation in the promoter and conserved non-coding sequence regions of the Foxp3 locus, suggesting a possible mechanism for how microbial-derived butyrate regulates the differentiation of Treg cells. Our findings provide new insight into the mechanisms by which host-microbe interactions establish immunological homeostasis in the gut.