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1.
Cell ; 176(5): 1098-1112.e18, 2019 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-30794774

RESUMO

Increased levels of intestinal bile acids (BAs) are a risk factor for colorectal cancer (CRC). Here, we show that the convergence of dietary factors (high-fat diet) and dysregulated WNT signaling (APC mutation) alters BA profiles to drive malignant transformations in Lgr5-expressing (Lgr5+) cancer stem cells and promote an adenoma-to-adenocarcinoma progression. Mechanistically, we show that BAs that antagonize intestinal farnesoid X receptor (FXR) function, including tauro-ß-muricholic acid (T-ßMCA) and deoxycholic acid (DCA), induce proliferation and DNA damage in Lgr5+ cells. Conversely, selective activation of intestinal FXR can restrict abnormal Lgr5+ cell growth and curtail CRC progression. This unexpected role for FXR in coordinating intestinal self-renewal with BA levels implicates FXR as a potential therapeutic target for CRC.


Assuntos
Neoplasias Intestinais/metabolismo , Células-Tronco Neoplásicas/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Animais , Ácidos e Sais Biliares/metabolismo , Linhagem Celular , Proliferação de Células/genética , Neoplasias Colorretais/metabolismo , Ácido Desoxicólico/metabolismo , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Neoplasias Intestinais/genética , Intestinos , Fígado , Camundongos , Camundongos Endogâmicos C57BL , Células-Tronco Neoplásicas/fisiologia , Organoides/metabolismo , Receptores Citoplasmáticos e Nucleares/genética , Fatores de Risco , Transdução de Sinais , Ácido Taurocólico/análogos & derivados , Ácido Taurocólico/metabolismo , Via de Sinalização Wnt/genética , Via de Sinalização Wnt/fisiologia
2.
Cell ; 153(3): 601-13, 2013 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-23622244

RESUMO

Liver fibrosis is a reversible wound-healing response involving TGFß1/SMAD activation of hepatic stellate cells (HSCs). It results from excessive deposition of extracellular matrix components and can lead to impairment of liver function. Here, we show that vitamin D receptor (VDR) ligands inhibit HSC activation by TGFß1 and abrogate liver fibrosis, whereas Vdr knockout mice spontaneously develop hepatic fibrosis. Mechanistically, we show that TGFß1 signaling causes a redistribution of genome-wide VDR-binding sites (VDR cistrome) in HSCs and facilitates VDR binding at SMAD3 profibrotic target genes via TGFß1-dependent chromatin remodeling. In the presence of VDR ligands, VDR binding to the coregulated genes reduces SMAD3 occupancy at these sites, inhibiting fibrosis. These results reveal an intersecting VDR/SMAD genomic circuit that regulates hepatic fibrogenesis and define a role for VDR as an endocrine checkpoint to modulate the wound-healing response in liver. Furthermore, the findings suggest VDR ligands as a potential therapy for liver fibrosis.


Assuntos
Redes Reguladoras de Genes , Fígado/metabolismo , Fígado/patologia , Receptores de Calcitriol/metabolismo , Transdução de Sinais , Animais , Calcitriol/análogos & derivados , Fibrose/prevenção & controle , Estudo de Associação Genômica Ampla , Células Estreladas do Fígado , Fígado/lesões , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ratos , Receptores de Calcitriol/agonistas , Proteína Smad3/metabolismo , Transcriptoma , Fator de Crescimento Transformador beta1/metabolismo
3.
Proc Natl Acad Sci U S A ; 119(51): e2213041119, 2022 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-36508655

RESUMO

The pleiotropic actions of the Farnesoid X Receptor (FXR) are required for gut health, and reciprocally, reduced intestinal FXR signaling is seen in inflammatory bowel diseases (IBDs). Here, we show that activation of FXR selectively in the intestine is protective in inflammation-driven models of IBD. Prophylactic activation of FXR restored homeostatic levels of pro-inflammatory cytokines, most notably IL17. Importantly, these changes were attributed to FXR regulation of innate lymphoid cells (ILCs), with both the inflammation-driven increases in ILCs, and ILC3s in particular, and the induction of Il17a and Il17f in ILC3s blocked by FXR activation. Moreover, a population of ILC precursor-like cells increased with treatment, implicating FXR in the maturation/differentiation of ILC precursors. These findings identify FXR as an intrinsic regulator of intestinal ILCs and a potential therapeutic target in inflammatory intestinal diseases.


Assuntos
Imunidade Inata , Doenças Inflamatórias Intestinais , Humanos , Linfócitos , Doenças Inflamatórias Intestinais/tratamento farmacológico , Citocinas , Inflamação
4.
Hepatology ; 71(4): 1213-1227, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31442319

RESUMO

BACKGROUND AND AIMS: Nonalcoholic fatty liver disease (NAFLD) affects a quarter of the adult population. A significant subset of patients are lean, but their underlying pathophysiology is not well understood. APPROACH AND RESULTS: We investigated the role of bile acids (BAs) and the gut microbiome in the pathogenesis of lean NAFLD. BA and fibroblast growth factor (FGF) 19 levels (a surrogate for intestinal farnesoid X receptor [FXR] activity), patatin-like phospholipase domain containing 3 (PNPLA3), and transmembrane 6 superfamily member 2 (TM6SF2) variants, and gut microbiota profiles in lean and nonlean NAFLD were investigated in a cohort of Caucasian patients with biopsy-proven NAFLD (n = 538), lean healthy controls (n = 30), and experimental murine models. Patients with lean NAFLD had a more favorable metabolic and histological profile compared with those with nonlean NAFLD (P < 0.05 for all). BA levels were significantly higher in NAFLD with advanced compared with earlier stages of liver fibrosis. Patients with lean NAFLD had higher serum secondary BA and FGF19 levels and reduced 7-alpha-hydroxy-4-cholesten-3-one (C4) levels (P < 0.05 for all). These differences were more profound in early compared with advanced stages of fibrosis (P < 0.05 for both). Lean patients demonstrated an altered gut microbiota profile. Similar findings were demonstrated in lean and nonlean murine models of NAFLD. Treating mice with an apical sodium-dependent BA transporter inhibitor (SC-435) resulted in marked increases in fgf15, a shift in the BA and microbiota profiles, and improved steatohepatitis in the lean model. CONCLUSIONS: Differences in metabolic adaptation between patients with lean and nonlean NAFLD, at least in part, explain the pathophysiology and provide options for therapy.


Assuntos
Ácidos e Sais Biliares/metabolismo , Microbioma Gastrointestinal , Hepatopatia Gordurosa não Alcoólica/metabolismo , Magreza/metabolismo , Adulto , Animais , Óxidos N-Cíclicos/uso terapêutico , Modelos Animais de Doenças , Feminino , Fatores de Crescimento de Fibroblastos/sangue , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/microbiologia , Fosfolipases A2 Independentes de Cálcio , Receptores Citoplasmáticos e Nucleares/metabolismo , Tropanos/uso terapêutico
5.
Liver Int ; 40(6): 1356-1365, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32243703

RESUMO

BACKGROUND: Bile acids (BAs) are synthesized by the liver and modified by gut bacteria, and may play an intermediary role between the gut microbiome and liver in promoting fibrosis in non-alcoholic fatty liver disease (NAFLD). We investigated the associations between serum and faecal BAs, gut microbiome and fibrosis in patients with and without NAFLD and examined the impact of diet and alcohol consumption on these relationships. METHODS: Adult patients (n = 122) underwent liver biopsy and BAs characterization by high-performance liquid chromatography/mass spectrometry. Gut microbiome composition was analysed using next-generation 16S rRNA sequencing. Diet and alcohol intake were determined by 3-day food diary. RESULTS: Serum and faecal BA concentrations increased progressively among non-NAFLD controls (n = 55), NAFLD patients with no/mild fibrosis (F0-2, n = 58) and NAFLD with advanced fibrosis (F3/4, n = 9). Progressive increases in serum BAs were driven by primary conjugated BAs including glycocholic acid [GCA] and secondary conjugated BAs. In contrast, faecal BA increase was driven by secondary unconjugated BAs (predominately deoxycholic acid [DCA]). Serum GCA levels and faecal DCA levels correlated with the abundance of Bacteroidaceae and Lachnospiraceae, and stool secondary BAs with an unclassifiable family of the order Bacteroidales (Bacteroidales;other). These bacterial taxa were also associated with advanced fibrosis. Modest alcohol consumption was positively correlated with faecal DCA levels and relative abundance of Lachnospiracaea and Bacteroidales;other. CONCLUSIONS: Higher serum and faecal BA levels are associated with advanced fibrosis in NAFLD. Specific gut bacteria link alterations in BA profiles and advanced fibrosis, and may be influenced by low-level alcohol consumption.


Assuntos
Microbioma Gastrointestinal , Hepatopatia Gordurosa não Alcoólica , Adulto , Consumo de Bebidas Alcoólicas/efeitos adversos , Ácidos e Sais Biliares , Humanos , Fígado , Cirrose Hepática , RNA Ribossômico 16S/genética
6.
Hepatology ; 67(6): 2150-2166, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29159825

RESUMO

Alcoholic liver disease (ALD) is associated with changes in the intestinal microbiota. Functional consequences of alcohol-associated dysbiosis are largely unknown. The aim of this study was to identify a mechanism of how changes in the intestinal microbiota contribute to ALD. Metagenomic sequencing of intestinal contents demonstrated that chronic ethanol feeding in mice is associated with an over-representation of bacterial genomic DNA encoding choloylglycine hydrolase, which deconjugates bile acids in the intestine. Bile acid analysis confirmed an increased amount of unconjugated bile acids in the small intestine after ethanol administration. Mediated by a lower farnesoid X receptor (FXR) activity in enterocytes, lower fibroblast growth factor (FGF)-15 protein secretion was associated with increased hepatic cytochrome P450 enzyme (Cyp)-7a1 protein expression and circulating bile acid levels. Depletion of the commensal microbiota with nonabsorbable antibiotics attenuated hepatic Cyp7a1 expression and reduced ALD in mice, suggesting that increased bile acid synthesis is dependent on gut bacteria. To restore intestinal FXR activity, we used a pharmacological intervention with the intestine-restricted FXR agonist fexaramine, which protected mice from ethanol-induced liver injury. Whereas bile acid metabolism was only minimally altered, fexaramine treatment stabilized the gut barrier and significantly modulated hepatic genes involved in lipid metabolism. To link the beneficial metabolic effect to FGF15, a nontumorigenic FGF19 variant-a human FGF15 ortholog-was overexpressed in mice using adeno-associated viruses. FGF19 treatment showed similarly beneficial metabolic effects and ameliorated alcoholic steatohepatitis. CONCLUSION: Taken together, alcohol-associated metagenomic changes result in alterations of bile acid profiles. Targeted interventions improve bile acid-FXR-FGF15 signaling by modulation of hepatic Cyp7a1 and lipid metabolism, and reduce ethanol-induced liver disease in mice. (Hepatology 2018;67:2150-2166).


Assuntos
Ácidos e Sais Biliares/fisiologia , Etanol/administração & dosagem , Fatores de Crescimento de Fibroblastos/fisiologia , Microbioma Gastrointestinal/fisiologia , Hepatopatias Alcoólicas/etiologia , Receptores Citoplasmáticos e Nucleares/fisiologia , Animais , Mucosa Intestinal/metabolismo , Intestinos/microbiologia , Camundongos , Camundongos Endogâmicos C57BL
7.
J Hepatol ; 69(2): 396-405, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29654817

RESUMO

BACKGROUND & AIMS: The degree of cholestasis is an important disease driver in alcoholic hepatitis, a severe clinical condition that needs new biomarkers and targeted therapies. We aimed to identify the largely unknown mechanisms and biomarkers linked to cholestasis in alcoholic hepatitis. METHODS: Herein, we analyzed a well characterized cohort of patients with alcoholic hepatitis and correlated clinical and histological parameters and outcomes with serum bile acids and fibroblast growth factor 19 (FGF19), a major regulator of bile acid synthesis. RESULTS: We found that total and conjugated bile acids were significantly increased in patients with alcoholic hepatitis compared with controls. Serum FGF19 levels were strongly increased and gene expression of FGF19 was induced in biliary epithelial cells and ductular cells of patients with alcoholic hepatitis. De novo bile acid synthesis (CYP7A1 gene expression and C4 serum levels) was significantly decreased in patients with alcoholic hepatitis. Importantly, total and conjugated bile acids correlated positively with FGF19 and with disease severity (model for end-stage liver disease score). FGF19 correlated best with conjugated cholic acid, and model for end-stage liver disease score best with taurine-conjugated chenodeoxycholic acid. Univariate analysis demonstrated significant associations between FGF19 and bilirubin as well as gamma glutamyl transferase, and negative correlations between FGF19 and fibrosis stage as well as polymorphonuclear leukocyte infiltration, in all patients with alcoholic hepatitis. CONCLUSION: Serum FGF19 and bile acids are significantly increased in patients with alcoholic hepatitis, while de novo bile acid synthesis is suppressed. Modulation of bile acid metabolism or signaling could represent a promising target for treatment of alcoholic hepatitis in humans. LAY SUMMARY: Understanding the underlying mechanisms that drive alcoholic hepatitis is important for the development of new biomarkers and targeted therapies. Herein, we describe a molecule that is increased in patients with alcoholic hepatitis. Modulating the molecular pathway of this molecule might lead to promising targets for the treatment of alcoholic hepatitis.


Assuntos
Ácidos e Sais Biliares , Colestase , Fatores de Crescimento de Fibroblastos/sangue , Hepatite Alcoólica , Neutrófilos/patologia , Ácidos e Sais Biliares/biossíntese , Ácidos e Sais Biliares/sangue , Ácidos e Sais Biliares/metabolismo , Biomarcadores/sangue , Colestase/etiologia , Colestase/metabolismo , Correlação de Dados , Feminino , Hepatite Alcoólica/sangue , Hepatite Alcoólica/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Infiltração de Neutrófilos , Índice de Gravidade de Doença , Transdução de Sinais/fisiologia
8.
Hepatology ; 60(1): 202-10, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24213952

RESUMO

UNLABELLED: Cholestatic liver dysfunction (CLD) and biliary sludge often occur during critical illness and are allegedly aggravated by parenteral nutrition (PN). Delaying initiation of PN beyond day 7 in the intensive care unit (ICU) (late PN) accelerated recovery as compared with early initiation of PN (early PN). However, the impact of nutritional strategy on biliary sludge and CLD has not been fully characterized. This was a preplanned subanalysis of a large randomized controlled trial of early PN versus late PN (n = 4,640). In all patients plasma bilirubin (daily) and liver enzymes (alanine aminotransferase [ALT], aspartate aminotransferase [AST], gamma-glutamyl transpeptidase [GGT], alkaline phosphatase [ALP], twice weekly; n = 3,216) were quantified. In a random predefined subset of patients, plasma bile acids (BAs) were also quantified at baseline and on days 3, 5, and last ICU-day (n = 280). Biliary sludge was ultrasonographically evaluated on ICU-day 5 (n = 776). From day 1 after randomization until the end of the 7-day intervention window, bilirubin was higher in the late PN than in the early PN group (P < 0.001). In the late PN group, as soon as PN was started on day 8 bilirubin fell and the two groups became comparable. Maximum levels of GGT, ALP, and ALT were lower in the late PN group (P < 0.01). Glycine/taurine-conjugated primary BAs increased over time in ICU (P < 0.01), similarly for the two groups. Fewer patients in the late PN than in the early PN group developed biliary sludge on day 5 (37% versus 45%; P = 0.04). CONCLUSION: Tolerating substantial caloric deficit by withholding PN until day 8 of critical illness increased plasma bilirubin but reduced the occurrence of biliary sludge and lowered GGT, ALP, and ALT. These results suggest that hyperbilirubinemia during critical illness does not necessarily reflect cholestasis and instead may be an adaptive response that is suppressed by early PN.


Assuntos
Bile , Bilirrubina/sangue , Colestase/prevenção & controle , Estado Terminal/terapia , Hiperbilirrubinemia/etiologia , Nutrição Parenteral/efeitos adversos , Idoso , Alanina Transaminase/sangue , Aspartato Aminotransferases/sangue , Ácidos e Sais Biliares/sangue , Colestase/sangue , Colestase/mortalidade , Estado Terminal/mortalidade , Feminino , Humanos , Hiperbilirrubinemia/sangue , Hiperbilirrubinemia/mortalidade , Incidência , Masculino , Pessoa de Meia-Idade , Nutrição Parenteral/métodos , Valor Preditivo dos Testes , Estudos Prospectivos , Fatores de Risco , gama-Glutamiltransferase/sangue
9.
Hepatology ; 57(6): 2180-8, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22996622

RESUMO

UNLABELLED: Advanced liver fibrosis in nonalcoholic steatohepatitis (NASH) is often accompanied by a reduction in hepatic fat to the point of complete fat loss (burnt-out NASH), but the mechanisms behind this phenomenon have not been elucidated. Adiponectin is raised in cirrhosis of any cause and has potent antisteatotic activity. In this study we examined 65 patients with advanced biopsy-proven NASH (fibrosis stage 3-4) and 54 with mild disease (fibrosis stage 0-1) to determine if disappearance of steatosis correlated with changes in serum adiponectin. All patents had fasting blood tests and anthropometric measures at the time of liver biopsy. Liver fat was accurately quantitated by morphometry. Serum adiponectin was measured by immunoassay. When compared to those with early disease, patients with advanced NASH were more insulin-resistant, viscerally obese, and older, but there was no difference in liver fat content or adiponectin levels. Adiponectin had a significant negative correlation with liver fat percentage in the whole cohort (r = -0.28, P < 0.01), driven by patients with advanced NASH (r = -0.40, P < 0.01). In advanced NASH, for each 4 µg/L increase in adiponectin there was an odds ratio OR of 2.0 (95% confidence interval [CI]: 1.3-3.0, P < 0.01) for a 5% reduction in hepatic fat. Adiponectin was highly and significantly associated with almost complete hepatic fat loss or burnt-out NASH (12.1 versus 7.4 µg/L, P = 0.001) on multivariate analysis. A relationship between adiponectin, bile acids, and adipocyte fexaramine activation was demonstrated in vivo and in vitro, suggestive of hepatocyte-adipocyte crosstalk. CONCLUSION: Serum adiponectin levels in advanced NASH are independently associated with hepatic fat loss. Adiponectin may in part be responsible for the paradox of burnt-out NASH. (HEPATOLOGY 2012).


Assuntos
Adiponectina/sangue , Fígado Gorduroso/sangue , Metabolismo dos Lipídeos , Fígado/metabolismo , Fígado/patologia , Adulto , Idoso , Ácidos e Sais Biliares/sangue , Biópsia , Estudos Transversais , Feminino , Fibrose , Humanos , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica
10.
JCI Insight ; 9(2)2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38258906

RESUMO

Bile acids (BAs) affect the intestinal environment by ensuring barrier integrity, maintaining microbiota balance, regulating epithelium turnover, and modulating the immune system. As a master regulator of BA homeostasis, farnesoid X receptor (FXR) is severely compromised in patients with inflammatory bowel disease (IBD) and colitis-associated colorectal cancer (CAC). At the front line, gut macrophages react to the microbiota and metabolites that breach the epithelium. We aim to study the role of the BA/FXR axis in macrophages. This study demonstrates that inflammation-induced epithelial abnormalities compromised FXR signaling and altered BAs' profile in a mouse CAC model. Further, gut macrophage-intrinsic FXR sensed aberrant BAs, leading to pro-inflammatory cytokines' secretion, which promoted intestinal stem cell proliferation. Mechanistically, activation of FXR ameliorated intestinal inflammation and inhibited colitis-associated tumor growth, by regulating gut macrophages' recruitment, polarization, and crosstalk with Th17 cells. However, deletion of FXR in bone marrow or gut macrophages escalated the intestinal inflammation. In summary, our study reveals a distinctive regulatory role of FXR in gut macrophages, suggesting its potential as a therapeutic target for addressing IBD and CAC.


Assuntos
Colite , Neoplasias do Colo , Receptores Citoplasmáticos e Nucleares , Animais , Camundongos , Ácidos e Sais Biliares , Colite/complicações , Neoplasias do Colo/etiologia , Modelos Animais de Doenças , Inflamação , Macrófagos , Receptores Citoplasmáticos e Nucleares/metabolismo
11.
Cell Rep ; 42(8): 112997, 2023 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-37611587

RESUMO

Colorectal cancer (CRC) is driven by genomic alterations in concert with dietary influences, with the gut microbiome implicated as an effector in disease development and progression. While meta-analyses have provided mechanistic insight into patients with CRC, study heterogeneity has limited causal associations. Using multi-omics studies on genetically controlled cohorts of mice, we identify diet as the major driver of microbial and metabolomic differences, with reductions in α diversity and widespread changes in cecal metabolites seen in high-fat diet (HFD)-fed mice. In addition, non-classic amino acid conjugation of the bile acid cholic acid (AA-CA) increased with HFD. We show that AA-CAs impact intestinal stem cell growth and demonstrate that Ileibacterium valens and Ruminococcus gnavus are able to synthesize these AA-CAs. This multi-omics dataset implicates diet-induced shifts in the microbiome and the metabolome in disease progression and has potential utility in future diagnostic and therapeutic developments.


Assuntos
Neoplasias Colorretais , Microbioma Gastrointestinal , Microbiota , Animais , Camundongos , Ácidos e Sais Biliares , Metaboloma
12.
Hepatology ; 54(5): 1741-52, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21800341

RESUMO

UNLABELLED: Hyperbilirubinemia is common during critical illness and is associated with adverse outcome. Whether hyperbilirubinemia reflects intensive care unit (ICU) cholestasis is unclear. Therefore, the aim of this study was to analyze hyperbilirubinemia in conjunction with serum bile acids (BAs) and the key steps in BA synthesis, transport, and regulation by nuclear receptors (NRs). Serum BA and bilirubin levels were determined in 130 ICU and 20 control patients. In liver biopsies messenger RNA (mRNA) expression of BA synthesis enzymes, BA transporters, and NRs was assessed. In a subset (40 ICU / 10 controls) immunohistochemical staining of the transporters and receptors together with a histological evaluation of cholestasis was performed. BA levels were much more elevated than bilirubin in ICU patients. Conjugated cholic acid (CA) and chenodeoxycholic acid (CDCA) were elevated, with an increased CA/CDCA ratio. Unconjugated BA did not differ between controls and patients. Despite elevated serum BA levels, CYP7A1 protein, the rate-limiting enzyme in BA synthesis, was not lowered in ICU patients. Also, protein expression of the apical bile salt export pump (BSEP) was decreased, whereas multidrug resistance-associated protein (MRP) 3 was strongly increased at the basolateral side. This reversal of BA transport toward the sinusoidal blood compartment is in line with the increased serum conjugated BA levels. Immunostaining showed marked down-regulation of nuclear farnesoid X receptor, retinoid X receptor alpha, constitutive androstane receptor, and pregnane X receptor nuclear protein levels. CONCLUSION: Failure to inhibit BA synthesis, up-regulate canalicular BA export, and localize pivotal NR in the hepatocytic nuclei may indicate dysfunctional feedback regulation by increased BA levels. Alternatively, critical illness may result in maintained BA synthesis (CYP7A1), reversal of normal BA transport (BSEP/MRP3), and inhibition of the BA sensor (FXR/RXRα) to increase serum BA levels.


Assuntos
Ácidos e Sais Biliares/sangue , Proteínas de Transporte/metabolismo , Colestase/metabolismo , Estado Terminal , Fígado/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Membro 11 da Subfamília B de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Idoso , Biópsia , Proteínas de Transporte/genética , Colestase/patologia , Colestase/fisiopatologia , Receptor Constitutivo de Androstano , Feminino , Humanos , Hiperbilirrubinemia/metabolismo , Hiperbilirrubinemia/patologia , Hiperbilirrubinemia/fisiopatologia , Fígado/patologia , Masculino , Proteína 2 Associada à Farmacorresistência Múltipla , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Transportadores de Ânions Orgânicos Dependentes de Sódio/genética , Transportadores de Ânions Orgânicos Dependentes de Sódio/metabolismo , Transportadores de Ânions Orgânicos Sódio-Independentes/genética , Transportadores de Ânions Orgânicos Sódio-Independentes/metabolismo , Receptor de Pregnano X , RNA Mensageiro/metabolismo , Receptores de Calcitriol/genética , Receptores de Calcitriol/metabolismo , Receptores Citoplasmáticos e Nucleares/genética , Receptores de Esteroides/genética , Receptores de Esteroides/metabolismo , Receptor X Retinoide alfa/genética , Receptor X Retinoide alfa/metabolismo , Simportadores/genética , Simportadores/metabolismo
13.
JHEP Rep ; 4(9): 100514, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35898957

RESUMO

Background & Aims: The chronicity of HBV (and resultant liver disease) is determined by intrahepatic persistence of the HBV covalently closed circular DNA (cccDNA), an episomal form that encodes all viral transcripts. Therefore, cccDNA is a key target for new treatments, with the ultimate therapeutic aim being its complete elimination. Although established cccDNA molecules are known to be stable in resting hepatocytes, we aimed to understand their fate in dividing cells using in vitro models. Methods: We infected HepG2-NTCP and HepaRG-NTCP cells with HBV and induced mitosis by passaging cells. We measured cccDNA copy number (by precise PCR assays) and HBV-expressing cells (by immunofluorescence) with wild-type HBV. We used reporter viruses expressing luciferase or RFP to track number of HBV-expressing cells over time after mitosis induction using luciferase assays and live imaging, respectively. Results: In all cases, we observed dramatic reductions in cccDNA levels, HBV-positive cell numbers, and cccDNA-dependent protein expression after each round of cell mitosis. The rates of reduction were highly consistent with mathematical models of a complete cccDNA loss in (as opposed to dilution into) daughter cells. Conclusions: Our results are concordant with previous animal models of HBV infection and show that HBV persistence can be efficiently overcome by inducing cell mitosis. These results support therapeutic approaches that induce liver turnover (e.g. immune modulators) in addition to direct-acting antiviral therapies to achieve hepatitis B cure. Lay summary: Chronic hepatitis B affects 300 million people (killing 884,000 per year) and is incurable. To cure it, we need to clear the HBV genome from the liver. In this study, we looked at how the virus behaves after a cell divides. We found that it completely clears the virus, making 2 new uninfected cells. Our work informs new approaches to develop cures for chronic hepatitis B infections.

14.
Breast ; 54: 229-234, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33161337

RESUMO

INTRODUCTION: CYP2D6 protein activity can be inferred from the ratio of N-desmethyl-tamoxifen (NDMT) to endoxifen (E). CYP2D6 polymorphisms are common and can affect CYP2D6 protein activity and E level. Some retrospective studies indicate that E < 16 nM may relate to worse outcome. MATERIALS AND METHODS: A target NDMT/E ratio was defined as associated with an E level of 15 nM in the 161 patient Test cohort of tamoxifen-treated patients, dichotomizing them into 'Normal' (NM) and 'Slow' (SM) CYP2D6 metabolizer groups. This ratio was then tested on a validation cohort of 52 patients. Patients were phenotyped based on the standard method (ultrarapid/extensive, intermediate or poor metabolizers; UM/EM, IM, PM) or a simplified system based on whether any variant allele (V) vs wildtype (wt) was present (wt/wt, wt/V, V/V). Comprehensive CYP2D6 genotyping was undertaken on germline DNA. RESULTS: A target NDMT/E ratio of 35 correlated with the 15 nM E level, dichotomizing patients into NM (<35; N = 117) and SM (>35; N = 44) groups. The ratio was independently validated by a validation cohort. The simplified system was better in predicting patients without slow metabolism, with specificity and sensitivity of 96% and 44% respectively, compared with the standard method - sensitivity 81% and specificity 83%. CONCLUSIONS: The simplified classification system based on whether any variant was present better identified patients who were truly not CYP2D6 slow metabolizers more accurately than the current system. However, as CYP2D6 genotype is not the only determinant of endoxifen level, we recommend that direct measurement of endoxifen should also be considered.


Assuntos
Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/genética , Citocromo P-450 CYP2D6/classificação , Tamoxifeno/análogos & derivados , Tamoxifeno/uso terapêutico , Adulto , Idoso , Alelos , Neoplasias da Mama/sangue , Neoplasias da Mama/tratamento farmacológico , Citocromo P-450 CYP2D6/genética , Monitoramento de Medicamentos/métodos , Feminino , Genótipo , Humanos , Pessoa de Meia-Idade , Fenótipo , Polimorfismo de Nucleotídeo Único , Estudos Prospectivos , Estudos Retrospectivos , Tamoxifeno/sangue
15.
Breast ; 46: 52-57, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31082762

RESUMO

OBJECTIVES: Severe hot flash (HF) toxicity due to tamoxifen can compromise compliance. We previously found that HFs did not correlate with endoxifen level or CYP2D6 genotype. In this study, we reduced tamoxifen dose in patients with severe HFs to determine whether HFs were ameliorated whilst maintaining a purported therapeutic endoxifen level of >15 nM. MATERIALS AND METHODS: Twenty patients with severe HFs on 20 mg TAM had CYP2D6genotype, trough level tamoxifen and metabolites measured with Loprinzi HF scores (HFS) derived before and after DR of tamoxifen to 10 mg. Other data collected included demographics, smoking, alcohol, menstrual and breast cancer history, previous chemotherapies, concurrent medications, BMI and other tamoxifen toxicities. RESULTS: At the 20 mg tamoxifen dose, endoxifen levels were 25.6, 0-91.9 nM (median, range) with HFS 131, 22-1482 (median, range). Upon DR to 10 mg, median endoxifen level fell to 14.1, 0.6-71.9 nM (difference in means p = 0.11, two-tailed T test) with HFS 47, 5-864 (difference in means p = 0.24, two-tailed T test). Despite lacking statistical significance, 85% of patients reported subjective improvement of HFs with DR. After DR, the proportion of patients with endoxifen level <15 nM increased from 20% to 50%. HFS did not correlate with any other parameter. CONCLUSION: DR of tamoxifen from 20 mg to 10 mg daily resulted in halving of endoxifen levels and subjective improvement of HF. While half the dose-reduced patients were below a potential therapeutic level of endoxifen, other recent studies suggest that low endoxifen levels may not indicate reduced effectiveness of tamoxifen.


Assuntos
Antineoplásicos Hormonais/efeitos adversos , Neoplasias da Mama/tratamento farmacológico , Fogachos/induzido quimicamente , Tamoxifeno/análogos & derivados , Tamoxifeno/efeitos adversos , Adulto , Antineoplásicos Hormonais/administração & dosagem , Neoplasias da Mama/genética , Citocromo P-450 CYP2D6 , Relação Dose-Resposta a Droga , Feminino , Genótipo , Humanos , Pessoa de Meia-Idade , Tamoxifeno/administração & dosagem , Tamoxifeno/sangue , Resultado do Tratamento
16.
Cancer Chemother Pharmacol ; 80(2): 385-393, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28667354

RESUMO

PURPOSE: Dose individualization of sunitinib has been proposed using therapeutic drug monitoring (TDM) or toxicity-adjusted dose (TAD). We prospectively studied aspects of TDM and TAD to inform future trials, namely (1) intrapatient variability (CV) of sunitinib and (2) feasibility of a TAD protocol. METHODS: Sunitinib dose was adjusted to ensure grade 1 or 2 toxicity on 10-20 days of each 42-day cycle. Total trough levels (TTL) C min of sunitinib and its active metabolite were measured every 6 weeks. RESULTS: In 45 patients with mRCC, 283 TTL samples were assayed over a median 30 weeks (6-108 weeks). Fifteen patients (33%) had an intrapatient CV of >25% in TTL. Ninety-one percent achieved target toxicity with a final sunitinib dose of 25 mg (18%), 37.5 mg (27%), 50 mg (50%), and 62.5 or 75 mg (7%). TTL C min was <50, 50-100, and >100 ng/mL in 7 (15%), 31 (69%), and 7 patients (15.5%), respectively. The median overall survival was 32 months. CONCLUSIONS: Sunitinib level has minimal variability in the majority of patients on stable dose. A subset of patients had a significant intrapatient variation, so we recommend two samples 4 to 6 months apart. TAD is feasible for dosing sunitinib and showed a favourable outcome.


Assuntos
Antineoplásicos/administração & dosagem , Carcinoma de Células Renais/tratamento farmacológico , Monitoramento de Medicamentos/métodos , Indóis/administração & dosagem , Neoplasias Renais/tratamento farmacológico , Pirróis/administração & dosagem , Adulto , Idoso , Antineoplásicos/efeitos adversos , Antineoplásicos/farmacocinética , Carcinoma de Células Renais/patologia , Relação Dose-Resposta a Droga , Feminino , Humanos , Indóis/efeitos adversos , Indóis/farmacocinética , Neoplasias Renais/patologia , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Estudos Prospectivos , Pirróis/efeitos adversos , Pirróis/farmacocinética , Sunitinibe , Taxa de Sobrevida , Fatores de Tempo
17.
Clin Cancer Res ; 22(13): 3164-71, 2016 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-26847054

RESUMO

PURPOSE: Endoxifen is the major mediator of tamoxifen effect and endoxifen levels <15 nmol/L may be associated with increased risk of breast cancer recurrence. We increased tamoxifen dose in breast cancer patients with low endoxifen levels and assessed the influence of various parameters on reaching 15 nmol/L and 30 nmol/L endoxifen levels. EXPERIMENTAL DESIGN: Tamoxifen dose was increased in those with endoxifen levels below 30 nmol/L. Toxicity, including hot flash score, was measured. CYP2D6 metabolizer status was classified as ultra-rapid (UM), extensive (EM), intermediate (IM), or poor (PM) based genotype of somatic DNA. RESULTS: Dosage was escalated in 68 of 122 participants. On 20 mg tamoxifen, 24% had endoxifen levels below 15 nmol/L and this reduced to 6% following dose escalation. In over 50% of cases, there was no identified cause for low endoxifen. Low baseline endoxifen level, and not CYP2D6 metabolizer status, independently predicted reaching threshold targets for both the 15 nmol/L and 30 nmol/L targets (P = 0.04 and 0.003 respectively). The 15 nmol/L target was reached in all UM/EM and IM patients, 63% of PM patients, and 58% of those with baseline endoxifen of <10 nmol/L. There was no correlation between hot flash score and genotype or any tamoxifen metabolite level including endoxifen (R = 0.07). CONCLUSIONS: Low endoxifen on standard dose tamoxifen was the only independent predictor of failure to achieve potentially therapeutic levels. Trials examining tamoxifen dose escalation and breast cancer outcome should be guided by endoxifen levels alone, without reference to CYP2D6 genotype or presence of hot flashes. Clin Cancer Res; 22(13); 3164-71. ©2016 AACRSee related commentary by Hertz and Rae, p. 3121.


Assuntos
Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Citocromo P-450 CYP2D6/metabolismo , Monitoramento de Medicamentos/métodos , Tamoxifeno/análogos & derivados , Tamoxifeno/uso terapêutico , Antineoplásicos Hormonais/administração & dosagem , Neoplasias da Mama/patologia , Citocromo P-450 CYP2D6/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/patologia , Tamoxifeno/administração & dosagem , Tamoxifeno/sangue
18.
Nat Med ; 21(2): 159-65, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25559344

RESUMO

The systemic expression of the bile acid (BA) sensor farnesoid X receptor (FXR) has led to promising new therapies targeting cholesterol metabolism, triglyceride production, hepatic steatosis and biliary cholestasis. In contrast to systemic therapy, bile acid release during a meal selectively activates intestinal FXR. By mimicking this tissue-selective effect, the gut-restricted FXR agonist fexaramine (Fex) robustly induces enteric fibroblast growth factor 15 (FGF15), leading to alterations in BA composition, but does so without activating FXR target genes in the liver. However, unlike systemic agonism, we find that Fex reduces diet-induced weight gain, body-wide inflammation and hepatic glucose production, while enhancing thermogenesis and browning of white adipose tissue (WAT). These pronounced metabolic improvements suggest tissue-restricted FXR activation as a new approach in the treatment of obesity and metabolic syndrome.


Assuntos
Tecido Adiposo Marrom/efeitos dos fármacos , Derivados de Benzeno/farmacologia , Ácidos e Sais Biliares/metabolismo , Fatores de Crescimento de Fibroblastos/efeitos dos fármacos , Resistência à Insulina , Mucosa Intestinal/metabolismo , Obesidade/metabolismo , Receptores Citoplasmáticos e Nucleares/agonistas , Aumento de Peso/efeitos dos fármacos , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/efeitos dos fármacos , Tecido Adiposo Branco/metabolismo , Animais , Fatores de Crescimento de Fibroblastos/metabolismo , Técnica Clamp de Glucose , Camundongos , Receptores Citoplasmáticos e Nucleares/metabolismo
19.
Endocrinology ; 144(9): 4008-17, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12933675

RESUMO

Treatment with high dose human GH, although an effective anabolic agent, has been associated with increased incidence of sepsis, inflammation, multiple organ failure, and death in critically ill patients. We hypothesized that GH might increase mortality by exacerbating cholestasis through modulation of bile acid transporter expression. High dose GH was continuously infused over 4 d into rats, and on the final day lipopolysaccharides were injected. Hepatic bile acid transporter expression was measured by Northern analysis and immunoblotting and compared with serum markers of cholestasis and endotoxinemia. Compared with non-GH-treated controls, GH increased endotoxin-induced markers of cholestasis and liver damage as well as augmented IL-6 induction. In endotoxinemia, GH treatment significantly induced multidrug resistance-associated protein 1 mRNA and protein and suppressed organic anion transporting polypeptides, Oatp1 and Oatp4, mRNA, suggesting impaired uptake of bilirubin and bile acids at the basolateral surface of the hepatocyte, which could contribute to the observed worsening of cholestasis by GH. This study of endotoxinemia may thus provide a mechanistic link between GH treatment and exacerbation of cholestasis through modulation of basolateral bile acid transporter expression in the rat hepatocyte.


Assuntos
Bile/metabolismo , Proteínas de Transporte/metabolismo , Colestase Intra-Hepática/metabolismo , Hormônio do Crescimento/farmacologia , Hidroxiesteroide Desidrogenases , Fígado/metabolismo , Glicoproteínas de Membrana , Proteínas de Membrana , Proteínas de Membrana Transportadoras , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Hidrocarboneto de Aril Hidroxilases/genética , Hidrocarboneto de Aril Hidroxilases/metabolismo , Biomarcadores , Proteínas de Transporte/genética , Colestase Intra-Hepática/induzido quimicamente , Citocromo P-450 CYP3A , Expressão Gênica , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Lipopolissacarídeos/farmacologia , Fígado/citologia , Fígado/efeitos dos fármacos , Masculino , Proteína 1 Transportadora de Ânions Orgânicos/genética , Proteína 1 Transportadora de Ânions Orgânicos/metabolismo , Transportadores de Ânions Orgânicos Dependentes de Sódio , Transportadores de Ânions Orgânicos Sódio-Independentes/genética , Transportadores de Ânions Orgânicos Sódio-Independentes/metabolismo , Ratos , Ratos Sprague-Dawley , Sepse/metabolismo , Sódio/metabolismo , Simportadores , Membro 4 da Subfamília B de Transportadores de Cassetes de Ligação de ATP
20.
Shock ; 41(1): 48-54, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24089008

RESUMO

BACKGROUND: Cholestatic liver dysfunction frequently occurs during critical illness. Administration of parenteral nutrition (PN) is thought to aggravate this. Underlying mechanisms are not clear. METHODS: In a burn model of prolonged critical illness, rabbits were randomized to a nutritional strategy either accepting caloric deficits (fasted, n = 11) or covering caloric needs by PN (fed, n = 10). At baseline and after 7 days of critical illness, markers of hepatotoxicity, circulating bile acids, and the hepatobiliary transport system were studied. RESULTS: Fasted animals had lower circulating alanine aminotransferase/aspartate aminotransferase levels than did the fed animals at day 7. Compared with baseline values, fed animals displayed lower serum unconjugated cholic acid (CA) and deoxycholic acid (DCA) levels. Unconjugated DCA remained unaltered in fasted animals. Unconjugated lithocholic acid was increased comparably in all animals, whereas hyodeoxycholic acid was not altered. In contrast, fasting induced a shift from unconjugated CA and DCA to glyco-CA and glyco-DCA. Total bile acids did not correlate with the bile acid-producing enzyme CYP7A1, but with the basolateral efflux transporter MRP3. Fasting increased protein expression of the basolateral (MRP3) and the canalicular (BSEP) transporter, whereas the canalicular efflux pump MRP2 was suppressed. Gene expression levels of the nuclear receptor farnesoid X receptor were lower with fasting and correlated inversely with MRP3. The heterodimer partner of farnesoid X receptor, retinoid X receptor α, was increased with fasting and correlated positively with MRP3. CONCLUSIONS: During prolonged critical illness, withholding PN improved markers for hepatocyte injury and accentuated bile acid transport toward the blood. This suggests that the latter is an adaptive rather than a dysfunctional feedback to illness.


Assuntos
Ácidos e Sais Biliares/biossíntese , Estado Terminal/terapia , Jejum/metabolismo , Fígado/metabolismo , Nutrição Parenteral , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Ácidos e Sais Biliares/sangue , Bilirrubina/metabolismo , Transporte Biológico/fisiologia , Biomarcadores/sangue , Colestase/etiologia , Colestase/metabolismo , Colestase/prevenção & controle , Modelos Animais de Doenças , Regulação da Expressão Gênica/fisiologia , Masculino , Proteínas Associadas à Resistência a Múltiplos Medicamentos/sangue , Nutrição Parenteral/efeitos adversos , Coelhos , Receptores Citoplasmáticos e Nucleares/biossíntese , Receptores Citoplasmáticos e Nucleares/genética , Receptor X Retinoide alfa/biossíntese , Receptor X Retinoide alfa/genética
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