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1.
Nat Commun ; 11(1): 4982, 2020 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-33020474

RESUMO

Nonalcoholic fatty liver disease (NAFLD) is associated with obesity but also found in non-obese individuals. Gut microbiome profiles of 171 Asians with biopsy-proven NAFLD and 31 non-NAFLD controls are analyzed using 16S rRNA sequencing; an independent Western cohort is used for external validation. Subjects are classified into three subgroups according to histological spectra of NAFLD or fibrosis severity. Significant alterations in microbiome diversity are observed according to fibrosis severity in non-obese, but not obese, subjects. Ruminococcaceae and Veillonellaceae are the main microbiota associated with fibrosis severity in non-obese subjects. Furthermore, stool bile acids and propionate are elevated, especially in non-obese subjects with significant fibrosis. Fibrosis-related Ruminococcaceae and Veillonellaceae species undergo metagenome sequencing, and four representative species are administered in three mouse NAFLD models to evaluate their effects on liver damage. This study provides the evidence for the role of the microbiome in the liver fibrosis pathogenesis, especially in non-obese subjects.


Assuntos
Bactérias/isolamento & purificação , Microbioma Gastrointestinal/fisiologia , Hepatopatia Gordurosa não Alcoólica/microbiologia , Hepatopatia Gordurosa não Alcoólica/patologia , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/metabolismo , Ácidos e Sais Biliares/análise , Ácidos e Sais Biliares/metabolismo , Biomarcadores , Fezes/química , Fezes/microbiologia , Fibrose , Microbioma Gastrointestinal/genética , Humanos , Cirrose Hepática/diagnóstico , Cirrose Hepática/metabolismo , Cirrose Hepática/microbiologia , Cirrose Hepática/patologia , Camundongos , Hepatopatia Gordurosa não Alcoólica/metabolismo , Obesidade/metabolismo , Obesidade/microbiologia , Obesidade/patologia , Propionatos/análise , Propionatos/metabolismo , RNA Ribossômico 16S/genética , Reprodutibilidade dos Testes
2.
PLoS One ; 15(9): e0232069, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32956351

RESUMO

Mouse models are frequently used to study mechanisms of human diseases. Recently, we observed a spontaneous bimodal variation in liver weight in C57BL/6JOlaHsd mice fed a semisynthetic diet. We now characterized the spontaneous variation in liver weight and its relationship with parameters of hepatic lipid and bile acid (BA) metabolism. In male C57BL/6JOlaHsd mice fed AIN-93G from birth to postnatal day (PN)70, we measured plasma BA, lipids, Very low-density lipoprotein (VLDL)-triglyceride (TG) secretion, and hepatic mRNA expression patterns. Mice were sacrificed at PN21, PN42, PN63 and PN70. Liver weight distribution was bimodal at PN70. Mice could be subdivided into two nonoverlapping groups based on liver weight: 0.6 SD 0.1 g (approximately one-third of mice, small liver; SL), and 1.0 SD 0.1 g (normal liver; NL; p<0.05). Liver histology showed a higher steatosis grade, inflammation score, more mitotic figures and more fibrosis in the SL versus the NL group. Plasma BA concentration was 14-fold higher in SL (p<0.001). VLDL-TG secretion rate was lower in SL mice, both absolutely (-66%, p<0.001) and upon correction for liver weight (-44%, p<0.001). Mice that would later have the SL-phenotype showed lower food efficiency ratios during PN21-28, suggesting the cause of the SL phenotype is present at weaning (PN21). Our data show that approximately one-third of C57BL/6JOlaHsd mice fed semisynthetic diet develop spontaneous liver disease with aberrant histology and parameters of hepatic lipid, bile acid and lipoprotein metabolism. Study designs involving this mouse strain on semisynthetic diets need to take the SL phenotype into account. Plasma lipids may serve as markers for the identification of the SL phenotype.


Assuntos
Ração Animal/efeitos adversos , Fígado Gorduroso/metabolismo , Fígado/patologia , Animais , Ácidos e Sais Biliares/sangue , Ácidos e Sais Biliares/metabolismo , Modelos Animais de Doenças , Ácidos Graxos/sangue , Ácidos Graxos/metabolismo , Fígado Gorduroso/sangue , Fígado Gorduroso/etiologia , Fígado Gorduroso/patologia , Feminino , Humanos , Metabolismo dos Lipídeos , Lipoproteínas VLDL/sangue , Lipoproteínas VLDL/metabolismo , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fatores Sexuais , Triglicerídeos/sangue , Triglicerídeos/metabolismo
3.
PLoS One ; 15(8): e0234750, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785220

RESUMO

The incidence of nonalcoholic steatohepatitis (NASH) is increasing worldwide, including in Asian countries. We reported that the hepatic expression of bile salt export pump (BSEP) was downregulated in patients with NASH, suggesting that BSEP is involved in the pathogenesis of NASH. To identify the underlying mechanism, we analyzed Bsep heterozygous knock-out (Bsep+/- mice) and wild-type (WT) C57BL/6J mice fed a high-fat diet (HFD) (32.0% animal fat) or normal diet. We examined histological changes, levels of hepatic lipids and hepatic bile acids, and expression of genes related to bile acid and cholesterol metabolism. HFD-fed Bsep+/- mice exhibited milder hepatic steatosis and less weight gain, compared to HFD-fed WT mice. The concentrations of total bile acid, triglycerides, and cholesterols were reduced in the liver of HFD-fed Bsep+/- mice. Regarding hepatic bile acid metabolism, the expression levels of Farnesoid X receptor (Fxr) and Multidrug resistance-associated protein 2 were significantly upregulated in HFD-fed Bsep+/- mice, compared to HFD-fed WT mice. Furthermore, several alterations were observed in upstream cholesterol metabolism in the liver. The expression levels of bile acid metabolism-related genes were also altered in the intestine of HFD-fed Bsep+/- mice. In conclusion, HFD-fed Bsep+/- mice exhibited significant alterations of the expression levels of genes related to bile acid and lipid metabolism in both the liver and ileum, resulting in alleviated steatosis and less weight gain. These results suggest the importance of BSEP for maintenance of bile acid and cholesterol metabolism. Further investigations of the involvement of BSEP in the pathogenesis of NASH will provide greater insight and facilitate the development of novel therapeutic modalities.


Assuntos
Membro 11 da Subfamília B de Transportadores de Cassetes de Ligação de ATP/deficiência , Dieta Hiperlipídica/efeitos adversos , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , Membro 11 da Subfamília B de Transportadores de Cassetes de Ligação de ATP/genética , Animais , Ácidos e Sais Biliares/metabolismo , Colesterol/metabolismo , Modelos Animais de Doenças , Heterozigoto , Íleo/metabolismo , Metabolismo dos Lipídeos , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Hepatopatia Gordurosa não Alcoólica/patologia
4.
Nat Commun ; 11(1): 3612, 2020 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-32681035

RESUMO

Bile acid synthesis plays a key role in regulating whole body cholesterol homeostasis. Transcriptional factor EB (TFEB) is a nutrient and stress-sensing transcriptional factor that promotes lysosomal biogenesis. Here we report a role of TFEB in regulating hepatic bile acid synthesis. We show that TFEB induces cholesterol 7α-hydroxylase (CYP7A1) in human hepatocytes and mouse livers and prevents hepatic cholesterol accumulation and hypercholesterolemia in Western diet-fed mice. Furthermore, we find that cholesterol-induced lysosomal stress feed-forward activates TFEB via promoting TFEB nuclear translocation, while bile acid-induced fibroblast growth factor 19 (FGF19), acting via mTOR/ERK signaling and TFEB phosphorylation, feedback inhibits TFEB nuclear translocation in hepatocytes. Consistently, blocking intestinal bile acid uptake by an apical sodium-bile acid transporter (ASBT) inhibitor decreases ileal FGF15, enhances hepatic TFEB nuclear localization and improves cholesterol homeostasis in Western diet-fed mice. This study has identified a TFEB-mediated gut-liver signaling axis that regulates hepatic cholesterol and bile acid homeostasis.


Assuntos
Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Ácidos e Sais Biliares/metabolismo , Colesterol/metabolismo , Fatores de Crescimento de Fibroblastos/metabolismo , Animais , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/antagonistas & inibidores , Linhagem Celular , Colesterol 7-alfa-Hidroxilase/metabolismo , Dieta Ocidental/efeitos adversos , Modelos Animais de Doenças , Células Hep G2 , Humanos , Hipercolesterolemia/etiologia , Hipercolesterolemia/metabolismo , Hipercolesterolemia/prevenção & controle , Íleo/efeitos dos fármacos , Íleo/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Transportadores de Ânions Orgânicos Dependentes de Sódio/antagonistas & inibidores , Simportadores/antagonistas & inibidores
5.
Nat Commun ; 11(1): 3692, 2020 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-32703946

RESUMO

Following birth, the neonatal intestine is exposed to maternal and environmental bacteria that successively form a dense and highly dynamic intestinal microbiota. Whereas the effect of exogenous factors has been extensively investigated, endogenous, host-mediated mechanisms have remained largely unexplored. Concomitantly with microbial colonization, the liver undergoes functional transition from a hematopoietic organ to a central organ of metabolic regulation and immune surveillance. The aim of the present study was to analyze the influence of the developing hepatic function and liver metabolism on the early intestinal microbiota. Here, we report on the characterization of the colonization dynamics and liver metabolism in the murine gastrointestinal tract (n = 6-10 per age group) using metabolomic and microbial profiling in combination with multivariate analysis. We observed major age-dependent microbial and metabolic changes and identified bile acids as potent drivers of the early intestinal microbiota maturation. Consistently, oral administration of tauro-cholic acid or ß-tauro-murocholic acid to newborn mice (n = 7-14 per group) accelerated postnatal microbiota maturation.


Assuntos
Ácidos e Sais Biliares/metabolismo , Microbioma Gastrointestinal , Administração Oral , Animais , Animais Recém-Nascidos , Ácidos e Sais Biliares/administração & dosagem , Absorção Intestinal , Cinética , Lactobacillus/fisiologia , Fígado/metabolismo , Metabolômica , Camundongos Endogâmicos C57BL , Filogenia , Análise de Componente Principal
6.
Am J Gastroenterol ; 115(7): 1094-1102, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32618660

RESUMO

INTRODUCTION: Bile acid (BA) diarrhea is the cause in ∼26% of chronic unexplained (nonbloody) diarrhea (CUD) based on SeHCAT testing. To assess fecal BA excretion and healthcare utilization in patients with CUD. METHODS: In a retrospective review of 1,071 consecutive patients with CUD who completed 48-hour fecal BA testing, we analyzed the symptoms, diagnostic tests performed, and final diagnoses. RESULTS: After 135 patients were excluded because of mucosal diseases, increased BA excretion was identified in 476 (51%) of the 936 patients with CUD: 29% with selective increase in primary BA and 22% with increased total BA excretion (35% with normal primary BA excretion). There were no differences in demographics, clinical symptoms, or history of cholecystectomy in patients with elevated total or selective primary fecal BA excretion compared with patients with normal excretion. Before the 48-hour fecal BA excretion test was performed, patients completed on average 1.2 transaxial imaging, 2.6 endoscopic procedures, and 1.6 miscellaneous tests/person. Less than 10% of these tests identified the etiology of CUD. Total fecal BAs >3,033 µmol/48 hour or primary BAs >25% had a 93% negative predictive value to exclude mucosal disease. Among patients with increased fecal BA excretion, >70% reported diarrhea improved with BA sequestrant compared with 26% with normal fecal BA excretion. Patients with selective elevation in primary fecal BAs were 3.1 times (95% confidence interval, 1.5-6.63) more likely to respond to BA sequestrant therapy compared with those with elevated total fecal BAs. DISCUSSION: Increased fecal BA excretion is frequent (51%) in patients with CUD. Early 48-hour fecal BA evaluation has the potential to decrease healthcare utilization in CUD.


Assuntos
Ácidos e Sais Biliares/metabolismo , Diarreia/diagnóstico , Diarreia/etiologia , Fezes/química , Adulto , Idoso , Doença Crônica , Diarreia/fisiopatologia , Feminino , Trânsito Gastrointestinal/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
7.
Proc Natl Acad Sci U S A ; 117(28): 16492-16499, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32601222

RESUMO

Metabolic stress causes activation of the cJun NH2-terminal kinase (JNK) signal transduction pathway. It is established that one consequence of JNK activation is the development of insulin resistance and hepatic steatosis through inhibition of the transcription factor PPARα. Indeed, JNK1/2 deficiency in hepatocytes protects against the development of steatosis, suggesting that JNK inhibition represents a possible treatment for this disease. However, the long-term consequences of JNK inhibition have not been evaluated. Here we demonstrate that hepatic JNK controls bile acid production. We found that hepatic JNK deficiency alters cholesterol metabolism and bile acid synthesis, conjugation, and transport, resulting in cholestasis, increased cholangiocyte proliferation, and intrahepatic cholangiocarcinoma. Gene ablation studies confirmed that PPARα mediated these effects of JNK in hepatocytes. This analysis highlights potential consequences of long-term use of JNK inhibitors for the treatment of metabolic syndrome.


Assuntos
Ácidos e Sais Biliares/metabolismo , Colangiocarcinoma/enzimologia , Proteína Quinase 8 Ativada por Mitógeno/metabolismo , Proteína Quinase 9 Ativada por Mitógeno/metabolismo , Animais , Colangiocarcinoma/genética , Colangiocarcinoma/metabolismo , Colangiocarcinoma/fisiopatologia , Homeostase , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína Quinase 8 Ativada por Mitógeno/genética , Proteína Quinase 9 Ativada por Mitógeno/genética , PPAR alfa/genética , PPAR alfa/metabolismo
8.
Toxicol Lett ; 331: 242-253, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32579994

RESUMO

Dysregulated bile acid (BA) homeostasis is an extremely significant pathological phenomenon of intrahepatic cholestasis, and the accumulated BA could further trigger hepatocyte injury. Here, we showed that the expression of sphingosine-1-phosphate receptor 1 (S1PR1) was down-regulated by α-naphthylisothiocyanate (ANIT) in vivo and in vitro. The up-regulated S1PR1 induced by SEW2871 (a specific agonist of S1PR1) could improve ANIT-induced deficiency of hepatocyte tight junctions (TJs), cholestatic liver injury and the disrupted BA homeostasis in mice. BA metabolic profiles showed that SEW2871 not only reversed the disruption of plasma BA homeostasis, but also alleviated BA accumulation in the liver of ANIT-treated mice. Further quantitative analysis of 19 BAs showed that ANIT increased almost all BAs in mice plasma and liver, all of which were restored by SEW2871. Our data demonstrated that the top performing BAs were taurine conjugated bile acids (T-), especially taurocholic acid (TCA). Molecular mechanism studies indicated that BA transporters, synthetase, and BAs nuclear receptors (NRs) might be the important factors that maintained BA homeostasis by SEW2871 in ANIT-induced cholestasis. In conclusion, these results demonstrated that S1PR1 selective agonists might be the novel and potential effective agents for the treatment of intrahepatic cholestasis by recovering dysregulated BA homeostasis.


Assuntos
1-Naftilisotiocianato/toxicidade , Ácidos e Sais Biliares/sangue , Colestase/prevenção & controle , Fígado/efeitos dos fármacos , Oxidiazóis/farmacologia , Receptores de Esfingosina-1-Fosfato/agonistas , Tiofenos/farmacologia , Animais , Ácidos e Sais Biliares/metabolismo , Colestase/induzido quimicamente , Colestase/metabolismo , Regulação para Baixo , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Hepatócitos/patologia , Homeostase , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos Endogâmicos C57BL , Receptores de Esfingosina-1-Fosfato/genética , Junções Íntimas/efeitos dos fármacos , Junções Íntimas/metabolismo , Junções Íntimas/patologia
9.
Am J Gastroenterol ; 115(10): 1596-1603, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32558690

RESUMO

Bile acids (BAs) are the central signals in enterohepatic communication, and they also integrate microbiota-derived signals into enterohepatic signaling. The tissue distribution and signaling pathways activated by BAs through natural receptors, farsenoid X receptor and G protein-coupled BA receptor 1 (GPBAR1, also known as Takeda G-coupled receptor 5), have led to a greater understanding of the mechanisms and potential therapeutic agents. BA diarrhea is most commonly encountered in ileal resection or disease, in idiopathic disorders (with presentation similar to functional diarrhea or irritable bowel syndrome with diarrhea), and in association with malabsorption such as chronic pancreatitis or celiac disease. Diagnosis of BA diarrhea is based on Se-homocholic acid taurine retention, 48-hour fecal BA excretion, or serum 7αC4; the latter being a marker of hepatic BA synthesis. BA diarrhea tends to be associated with higher body mass index, increased stool weight and stool fat, and acceleration of colonic transit. Biochemical markers of increased BA synthesis or excretion are available through reference laboratories. Current treatment of BA diarrhea is based on BA sequestrants, and, in the future, it is anticipated that farsenoid X receptor agonists may also be effective. The optimal conditions for an empiric trial with BA sequestrants as a diagnostic test are still unclear. However, such therapeutic trials are widely used in clinical practice. Some national guidelines recommend definitive diagnosis of BA diarrhea over empirical trial.


Assuntos
Ácidos e Sais Biliares/metabolismo , Diarreia/metabolismo , Diarreia/terapia , Dieta com Restrição de Gorduras , Sequestrantes/uso terapêutico , Benzotiazóis/uso terapêutico , Ácido Quenodesoxicólico/análogos & derivados , Ácido Quenodesoxicólico/uso terapêutico , Colestenonas/sangue , Resina de Colestiramina/uso terapêutico , Doença Crônica , Cloridrato de Colesevelam/uso terapêutico , Colestipol/uso terapêutico , Fezes/química , Humanos , Mucosa Intestinal/metabolismo , Síndrome do Intestino Irritável/metabolismo , Isoxazóis/uso terapêutico , Fígado/metabolismo , Síndromes de Malabsorção/diagnóstico , Síndromes de Malabsorção/tratamento farmacológico , Síndromes de Malabsorção/metabolismo , Receptores Citoplasmáticos e Nucleares/agonistas , Ácido Taurocólico/análogos & derivados
10.
J Nutr ; 150(8): 2031-2040, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32597983

RESUMO

BACKGROUND: The healthy human metabolome, including its physiological responses after meal consumption, remains incompletely understood. One major research gap is the limited literature assessing how human metabolomic profiles differ between fasting and postprandial states after physiological challenges. OBJECTIVES: Our study objective was to evaluate alterations in high-resolution metabolomic profiles following a standardized meal challenge, relative to fasting, in Guatemalan adults. METHODS: We studied 123 Guatemalan adults without obesity, hypertension, diabetes, metabolic syndrome, or comorbidities. Every participant received a standardized meal challenge (520 kcal, 67.4 g carbohydrates, 24.3 g fat, 8.0 g protein) and provided blood samples while fasting and at 2 h postprandial. Plasma samples were assayed by high-resolution metabolomics with dual-column LC [C18 (negative electrospray ionization), hydrophilic interaction LC (HILIC, positive electrospray ionization)] coupled to ultra-high-resolution MS. Associations between metabolomic features and the meal challenge timepoint were assessed in feature-by-feature multivariable linear mixed regression models. Two algorithms (mummichog, gene set enrichment analysis) were used for pathway analysis, and P values were combined by the Fisher method. RESULTS: Among participants (62.6% male, median age 43.0 y), 1130 features (C18: 777; HILIC: 353) differed between fasting and postprandial states (all false discovery rate-adjusted q < 0.05). Based on differing C18 features, top pathways included: tricarboxylic acid cycle (TCA), primary bile acid biosynthesis, and linoleic acid metabolism (all Pcombined < 0.05). Mass spectral features included: taurine and cholic acid in primary bile acid biosynthesis; and fumaric acid, malic acid, and citric acid in the TCA. HILIC features that differed in the meal challenge reflected linoleic acid metabolism (Pcombined < 0.05). CONCLUSIONS: Energy, macronutrient, and bile acid metabolism pathways were responsive to a standardized meal challenge in adults without cardiometabolic diseases. Our findings reflect metabolic flexibility in disease-free individuals.


Assuntos
Ácidos e Sais Biliares/metabolismo , Metabolismo Energético/fisiologia , Jejum , Refeições , Nutrientes/metabolismo , Adulto , Feminino , Guatemala , Humanos , Masculino , Pessoa de Meia-Idade
11.
Toxicol Lett ; 332: 97-106, 2020 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-32599024

RESUMO

As important members in steroids related signal pathways, bile acids are very important in regulating substance metabolism and immune homeostasis. However, bile acids are highly cytotoxic, and the excessive accumulation can induce several abnormalities such as cholestatic liver injury. It is known that the bile acid metabolism alters during pregnancy and mostly will not result in pathologies. However, the effect of dexamethasone exposure during pregnancy on bile acid metabolism is still unknown. In this study, pregnant Wistar rats were subcutaneously administered dexamethasone (0.2 mg/kg.d) or saline from gestation day 9-21, while virgin rats were given the same treatment for 13 days. We found that, physiological pregnancy or dexamethasone exposure during non-pregnancy did not affect maternal serum TBA level and liver function. Nevertheless, dexamethasone exposure during pregnancy increased serum TBA level and accompanied with liver injury. Furthermore, we discovered that the conservation of bile acid homeostasis under pregnancy or dexamethasone exposure was maintained through compensatory pathways. However, dexamethasone exposure during pregnancy tipped the balance of liver bile acid homeostasis by increasing classical synthesis and decreasing efflux and uptake. In addition, dexamethasone exposure during pregnancy also increased serum estrogen level and nuclear receptors mRNA expression levels. Finally, two-way ANOVA analysis showed that dexamethasone exposure during pregnancy could induce or facilitate maternal cholestasis and liver injury by up-regulating ERα and CYP7A1 expression. This study confirmed that dexamethasone exposure during pregnancy was related to maternal intrahepatic cholestasis of pregnancy and should be carefully monitored in clinical settings.


Assuntos
Ácidos e Sais Biliares/metabolismo , Dexametasona/toxicidade , Animais , Colestase Intra-Hepática , Colesterol 7-alfa-Hidroxilase/biossíntese , Estrogênios/sangue , Feminino , Hormônios Esteroides Gonadais/sangue , Homeostase/efeitos dos fármacos , Infusões Subcutâneas , Testes de Função Hepática , Gravidez , Ratos , Ratos Wistar , Receptores Estrogênicos/biossíntese
12.
J Toxicol Sci ; 45(6): 339-347, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32493876

RESUMO

The metabolomic profiles of rat primary hepatocytes following treatment with rotenone, FCCP, or (+)-usnic acid were determined using liquid chromatography-mass spectrometry/mass spectrometry and gas chromatography-mass spectrometry. Significant and similar changes in the levels of 283 biochemical metabolites were associated with the three treatments compared with solvent control samples. Overall, the three treatments generated similar global biochemical profiles, with some minor differences associated with rotenone treatment. All three treatments resulted in a shift in energy metabolism as demonstrated by decreased glycogen stores and glycolysis. A reduced antioxidant response was detected in cells following all treatments. In addition, bile acid biosynthesis decreased as a potential consequence of increased oxidative stress by all three treatments. Conversely, rotenone treatment induced a number of changes after 1 hr, which were not detected in FCCP- or (+)-usnic acid-treated samples; these changes were not sustained over time and included increased NAD+ salvage and lysine degradation. In conclusion, these biochemical profiles could provide new insights into the mechanism(s) of mitochondrial toxicity.


Assuntos
Benzofuranos/efeitos adversos , Carbonil Cianeto p-Trifluormetoxifenil Hidrazona/efeitos adversos , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Rotenona/efeitos adversos , Animais , Ácidos e Sais Biliares/metabolismo , Células Cultivadas , Cromatografia Líquida , Metabolismo Energético/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Glicogênio/metabolismo , Glicólise/efeitos dos fármacos , Metabolômica , Mitocôndrias Hepáticas/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Ratos Endogâmicos F344
13.
Am J Physiol Gastrointest Liver Physiol ; 319(2): G197-G211, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32597707

RESUMO

Intrahepatic cholestasis of pregnancy (ICP) is characterized by elevated maternal circulating bile acid levels and associated dyslipidemia. ICP leads to accumulation of bile acids in the fetal compartment, and the elevated bile acid concentrations are associated with an increased risk of adverse fetal outcomes. The farnesoid X receptor agonist obeticholic acid (OCA) is efficient in the treatment of cholestatic conditions such as primary biliary cholangitis. We hypothesized that OCA administration during hypercholanemic pregnancy will improve maternal and fetal bile acid and lipid profiles. Female C57BL/6J mice were fed either a normal chow diet, a 0.5% cholic acid (CA)-supplemented diet, a 0.03% OCA-supplemented diet, or a 0.5% CA + 0.03% OCA-supplemented diet for 1 wk before mating and throughout pregnancy until euthanization on day 18. The effects of CA and OCA feeding on maternal and fetal morphometry, bile acid and lipid levels, and cecal microbiota were investigated. OCA administration during gestation did not alter the maternal or fetal body weight or organ morphometry. OCA treatment during hypercholanemic pregnancy reduced bile acid levels in the fetal compartment. However, fetal dyslipidemia was not reversed, and OCA did not impact maternal bile acid levels or dyslipidemia. In conclusion, OCA administration during gestation had no apparent detrimental impact on maternal or fetal morphometry and improved fetal hypercholanemia. Because high serum bile acid concentrations in ICP are associated with increased rates of adverse fetal outcomes, further investigations into the potential use of OCA during cholestatic gestation are warranted.NEW & NOTEWORTHY We used a mouse model of gestational hypercholanemia to investigate the use of obeticholic acid (OCA), a potent FXR agonist, as a treatment for the hypercholanemia of intrahepatic cholestasis of pregnancy (ICP). The results demonstrate that OCA can improve the fetal bile acid profile. This is relevant not only to women with ICP but also for women who become pregnant while receiving OCA treatment for other conditions such as primary biliary cholangitis and nonalcoholic steatohepatitis.


Assuntos
Ácidos e Sais Biliares/sangue , Ácido Quenodesoxicólico/análogos & derivados , Colestase Intra-Hepática/tratamento farmacológico , Complicações na Gravidez/tratamento farmacológico , Animais , Ácidos e Sais Biliares/metabolismo , Ceco , Ácido Quenodesoxicólico/farmacologia , Colesterol 7-alfa-Hidroxilase/genética , Colesterol 7-alfa-Hidroxilase/metabolismo , Dislipidemias/tratamento farmacológico , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Gravidez , RNA Ribossômico 16S , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo
14.
Nature ; 582(7813): 566-570, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32555455

RESUMO

The gut microbiota synthesize hundreds of molecules, many of which influence host physiology. Among the most abundant metabolites are the secondary bile acids deoxycholic acid (DCA) and lithocholic acid (LCA), which accumulate at concentrations of around 500 µM and are known to block the growth of Clostridium difficile1, promote hepatocellular carcinoma2 and modulate host metabolism via the G-protein-coupled receptor TGR5 (ref. 3). More broadly, DCA, LCA and their derivatives are major components of the recirculating pool of bile acids4; the size and composition of this pool are a target of therapies for primary biliary cholangitis and nonalcoholic steatohepatitis. Nonetheless, despite the clear impact of DCA and LCA on host physiology, an incomplete knowledge of their biosynthetic genes and a lack of genetic tools to enable modification of their native microbial producers limit our ability to modulate secondary bile acid levels in the host. Here we complete the pathway to DCA and LCA by assigning and characterizing enzymes for each of the steps in its reductive arm, revealing a strategy in which the A-B rings of the steroid core are transiently converted into an electron acceptor for two reductive steps carried out by Fe-S flavoenzymes. Using anaerobic in vitro reconstitution, we establish that a set of six enzymes is necessary and sufficient for the eight-step conversion of cholic acid to DCA. We then engineer the pathway into Clostridium sporogenes, conferring production of DCA and LCA on a nonproducing commensal and demonstrating that a microbiome-derived pathway can be expressed and controlled heterologously. These data establish a complete pathway to two central components of the bile acid pool.


Assuntos
Ácidos e Sais Biliares/química , Ácidos e Sais Biliares/metabolismo , Microbioma Gastrointestinal/genética , Microbioma Gastrointestinal/fisiologia , Hidroxilação/genética , Redes e Vias Metabólicas/genética , Animais , Clostridium/enzimologia , Clostridium/genética , Clostridium/metabolismo , Ácido Desoxicólico/química , Ácido Desoxicólico/metabolismo , Ácido Litocólico/química , Ácido Litocólico/metabolismo , Masculino , Engenharia Metabólica , Camundongos , Óperon/genética , Simbiose
15.
Am J Physiol Gastrointest Liver Physiol ; 319(2): G227-G237, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32597706

RESUMO

Antibiotic treatment is a standard therapy for Clostridioides difficile infection, but dysbiosis of the gut microbiota due to antibiotic exposure is also a major risk factor for the disease. Following an initial episode of C. difficile infection, a relentless cycle of recurrence can occur, where persistent treatment-related dysbiosis predisposes the patient to subsequent relapse. This study uses a longitudinal study design to compare the effects of a narrow-spectrum (ridinilazole) or broad-spectrum antibiotic (vancomycin) on intestinal bile acid profiles and their associations with gut bacteria over the course of C. difficile infection treatment. At the end of treatment (day 10), subjects receiving vancomycin showed a nearly 100-fold increase in the ratio of conjugated to secondary bile acids in their stool compared with baseline, whereas subjects receiving ridinilazole maintained this ratio near baseline levels. Correlation analysis detected significant positive associations between secondary bile acids and several Bacteroidales and Clostridiales families. These families were depleted in the vancomycin group but preserved at near-baseline abundance in the ridinilazole group. Enterobacteriaceae, which expanded to a greater extent in the vancomycin group, correlated negatively and positively with secondary and conjugated primary bile acids, respectively. Bile acid ratios at the end of treatment were significantly different between those who recurred and those who did not. These results indicate that a narrow-spectrum antibiotic maintains an intestinal bile acid profile associated with a lowered risk of recurrence.NEW & NOTEWORTHY This is the first study to demonstrate in humans the relationships between Clostridioides difficile antibiotic treatment choice and bile acid metabolism both during therapy and after treatment cessation. The results show a microbiota- and metabolome-preserving property of a novel narrow-spectrum agent that correlates with the agent's favorable sustained clinical response rates compared with broad-spectrum antibiotic treatment.


Assuntos
Antibacterianos/farmacologia , Benzimidazóis/farmacologia , Ácidos e Sais Biliares/química , Clostridiales/efeitos dos fármacos , Microbioma Gastrointestinal/efeitos dos fármacos , Piridinas/farmacologia , Ácidos e Sais Biliares/metabolismo , Fezes/química , Microbioma Gastrointestinal/fisiologia , Humanos
16.
J Pharmacol Exp Ther ; 374(1): 175-183, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32366600

RESUMO

Besides diet therapy, hypolipidemic pharmacological therapy may be a crucial component of nonalcoholic fatty liver disease (NAFLD) treatment. Ezetimibe may be a promising drug for treatment of NAFLD. n-3 polyunsaturated fatty acids, which are abundant in fish oil, reduce serum and hepatic cholesterol and triglycerides in rodents. The aim of this study was to examine the combined effects of dietary fish oil and ezetimibe on lipid metabolism in rats. Seven-week-old male Sprague-Dawley rats were allocated to four different diets containing 1) 10% soybean oil (C), 2) 10% fish oil (F), 3) 10% soybean oil + 0.005% ezetimibe, and 4) 10% fish oil + 0.005% ezetimibe (F+E) for 4 weeks, when the liver, jejunum, blood, and fecal samples were collected. Compared with the C group, the F+E diet decreased hepatic triglycerides and cholesterol 84% and 86%, but it did not increase fecal cholesterol. In liver, the expression of lipogenic enzymes was decreased in the F+E diet, whereas ß-oxidation-related genes were not increased. Abcg5/g8 mRNA expression was increased 1380%/442% when ezetimibe was added to the F diet. These gene expression changes are related to the decrease in hepatic lipids. In jejunum, Abcg5/g8 mRNA was increased 244%/841% when ezetimibe was added to the F diet. Hepatic induction of Abcg5/8 rather than intestinal induction correlates with the marked decrease in liver cholesterol when ezetimibe was added to the F diet. These data suggest that fish oil diet and ezetimibe in combination may be a beneficial therapy for NAFLD by increasing hepatic Abcg5/g8 and decreasing lipogenic genes. SIGNIFICANCE STATEMENT: There is currently no single treatment for NAFLD. Thus, lifestyle modifications including dietary regulation and physical activity are also important options. In this study, ezetimibe, a cholesterol absorption inhibitor, was evaluated for the treatment of liver steatosis in rats fed on the different diets. We found that ezetimibe and fish oil in combination markedly improved fatty liver by increasing cholesterol efflux transporters. The combination therapy of fish oil agents and ezetimibe may be effective for NAFLD.


Assuntos
Colesterol/metabolismo , Ezetimiba/farmacologia , Óleos de Peixe/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Fígado/efeitos dos fármacos , Proteínas de Membrana Transportadoras/genética , Triglicerídeos/metabolismo , Animais , Ácidos e Sais Biliares/biossíntese , Ácidos e Sais Biliares/metabolismo , Transporte Biológico/efeitos dos fármacos , Homeostase/efeitos dos fármacos , Fígado/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley
17.
Neurobiol Aging ; 92: 114-134, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32417748

RESUMO

Evidence suggests that changes in intestinal microbiota may affect the central nervous system. However, it is unclear whether alteration of intestinal microbiota affects progression of Alzheimer's disease (AD). To understand this, wild-type control (C57BL/6) mice were compared with the AppNL-G-F model of disease. We used probiotic supplementation to manipulate the gut microbiota. Fecal samples were collected for microbiota profiling. To study brain and intestinal inflammation, biochemical and histological analyses were performed. Altered metabolic pathways were examined by quantifying eicosanoid and bile acid profiles in the brain and serum using ultraperformance liquid chromatography-tandem mass spectrometry. We observed that brain pathology was associated with intestinal dysbiosis and increased intestinal inflammation and leakiness in AppNL-G-F mice. Probiotic supplementation significantly decreased intestinal inflammation and gut permeability with minimal effect on amyloid-ß, cytokine, or gliosis levels in the brain. Concentrations of several bile acids and prostaglandins were altered in the serum and brain because of AD or probiotic supplementation. Our study characterizes intestinal dysfunction in an AD mouse model and the potential of probiotic intervention to ameliorate this condition.


Assuntos
Doença de Alzheimer/etiologia , Doença de Alzheimer/microbiologia , Encéfalo/metabolismo , Encéfalo/patologia , Microbioma Gastrointestinal/efeitos dos fármacos , Probióticos/administração & dosagem , Probióticos/farmacologia , Doença de Alzheimer/metabolismo , Doença de Alzheimer/prevenção & controle , Peptídeos beta-Amiloides/metabolismo , Animais , Ácidos e Sais Biliares/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Eicosanoides/metabolismo , Feminino , Gliose , Inflamação , Camundongos Endogâmicos C57BL , Camundongos Transgênicos
18.
Toxicol Lett ; 331: 11-21, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32439580

RESUMO

Cholestasis represents pathophysiologic syndromes defined as impaired bile flow from the liver. As an outcome, bile acids accumulate and promote hepatocyte injury, followed by liver cirrhosis and liver failure. Glycochenodeoxycholic acid (GCDCA) is relatively toxic and highly concentrated in bile and serum after cholestasis. However, the mechanism underlying GCDCA-induced hepatotoxicity remains unclear. In this study, we found that GCDCA inhibits autophagosome formation and impairs lysosomal function by inhibiting lysosomal proteolysis and increasing lysosomal pH, contributing to defects in autophagic clearance and subsequently leading to the death of L02 human hepatocyte cells. Notably, through tandem mass tag (TMT)-based quantitative proteomic analysis and database searches, 313 differentially expressed proteins were identified, of which 71 were increased and 242 were decreased in the GCDCA group compared with those in the control group. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that GCDCA suppressed the signaling pathway of transcription factor E3 (TFE3), which was the most closely associated with autophagic flux impairment. In contrast, GCDCA-inhibited lysosomal function and autophagic flux were efficiently attenuated by TFE3 overexpression. Specifically, the decreased expression of TFE3 was closely related to the disruption of reactive oxygen species (ROS) homeostasis, which could be prevented by inhibiting intracellular ROS with N-acetyl cysteine (NAC). In summary, our study is the first to demonstrate that manipulation of ROS/TFE3 signaling may be a therapeutic approach for antagonizing GCDCA-induced hepatotoxicity.


Assuntos
Autofagia/efeitos dos fármacos , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Ácido Glicoquenodesoxicólico/toxicidade , Hepatócitos/efeitos dos fármacos , Homeostase/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Ácidos e Sais Biliares/metabolismo , Linhagem Celular , Expressão Gênica/efeitos dos fármacos , Hepatócitos/metabolismo , Hepatócitos/patologia , Humanos , Lisossomos/efeitos dos fármacos , Proteômica
19.
Nature ; 581(7809): 475-479, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32461639

RESUMO

Intestinal health relies on the immunosuppressive activity of CD4+ regulatory T (Treg) cells1. Expression of the transcription factor Foxp3 defines this lineage, and can be induced extrathymically by dietary or commensal-derived antigens in a process assisted by a Foxp3 enhancer known as conserved non-coding sequence 1 (CNS1)2-4. Products of microbial fermentation including butyrate facilitate the generation of peripherally induced Treg (pTreg) cells5-7, indicating that metabolites shape the composition of the colonic immune cell population. In addition to dietary components, bacteria modify host-derived molecules, generating a number of biologically active substances. This is epitomized by the bacterial transformation of bile acids, which creates a complex pool of steroids8 with a range of physiological functions9. Here we screened the major species of deconjugated bile acids for their ability to potentiate the differentiation of pTreg cells. We found that the secondary bile acid 3ß-hydroxydeoxycholic acid (isoDCA) increased Foxp3 induction by acting on dendritic cells (DCs) to diminish their immunostimulatory properties. Ablating one receptor, the farnesoid X receptor, in DCs enhanced the generation of Treg cells and imposed a transcriptional profile similar to that induced by isoDCA, suggesting an interaction between this bile acid and nuclear receptor. To investigate isoDCA in vivo, we took a synthetic biology approach and designed minimal microbial consortia containing engineered Bacteroides strains. IsoDCA-producing consortia increased the number of colonic RORγt-expressing Treg cells in a CNS1-dependent manner, suggesting enhanced extrathymic differentiation.


Assuntos
Bactérias/metabolismo , Ácidos e Sais Biliares/química , Ácidos e Sais Biliares/metabolismo , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/imunologia , Sequência de Aminoácidos , Animais , Bacteroides/metabolismo , Colo/microbiologia , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Feminino , Fermentação , Microbioma Gastrointestinal , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Consórcios Microbianos , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo
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