RESUMEN
Oleanolic acid (OA) is a naturally occurring pentacyclic triterpene compound that has been reported to cause cholestatic liver injury. However, the regulation and pathogenic role of bile acids in OA-induced development of cholestatic liver injury remains largely unclear. Farnesoid X receptor (FXR) is a metabolic nuclear receptor that plays an important role in bile acid homeostasis in the liver by regulating efflux transporters bile salt export pump (BSEP) and multidrug resistance-associated protein 2 (MRP2). The aim of this study was to investigate the effect of OA on hepatocyte tight junction function and determine the role of FXR, BSEP, and MRP2 in the mechanism of impairment of transport of bile acids induced by OA. Both in vivo and in vitro models were used to characterize the OA-induced liver injury. The liquid chromatography-tandem mass spectrometry (LC-MS) was employed to characterize the efflux function of the transporters, and the results showed that OA caused a blockage of bile acids efflux. OA treatment resulted in decreased expression levels of the tight junction proteins zonula occludens-1 and occludin. Immunofluorescence results showed that OA treatment significantly reduced the number of bile ducts and the immunofluorescence intensity. Pretreatment with agonists of FXR and MRP2, respectively, in animal experiments attenuated OA-induced liver injury, while pretreatment with inhibitors of BSEP and MRP2 further aggravated OA-induced liver injury. These results suggest that OA inhibits FXR-mediated BSEP and MRP2, leading to impaired bile acid efflux and disruption of tight junctions between liver cells, resulting in liver damage.
Asunto(s)
Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP , Ácidos y Sales Biliares , Hepatocitos , Ácido Oleanólico , Receptores Citoplasmáticos y Nucleares , Uniones Estrechas , Ácido Oleanólico/farmacología , Ácido Oleanólico/análogos & derivados , Animales , Receptores Citoplasmáticos y Nucleares/metabolismo , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Uniones Estrechas/efectos de los fármacos , Uniones Estrechas/metabolismo , Ácidos y Sales Biliares/metabolismo , Masculino , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Humanos , Proteína 2 Asociada a Resistencia a Múltiples Medicamentos , Ratones , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/metabolismo , Hígado/efectos de los fármacos , Hígado/metabolismo , Ratones Endogámicos C57BLRESUMEN
Antituberculosis drugs induce pharmacologic cholestatic liver injury with long-term administration. Liver injury resulting from rifampicin is potentially related to the bile acid nuclear receptor Farnesoid X Receptor (FXR). To investigate this, cholestasis was induced in both wild-type (C57BL/6N) mice and FXR knockout (FXR-null) mice through administration of rifampicin (200 mg/kg) via gavage for 7 consecutive days. Compared with C57BL/6N mice, FXR-null mice exhibited more severe liver injury after rifampicin administration, characterized by enlarged liver size, elevated transaminases, and increased inflammation. Moreover, under rifampicin treatment, FXR knockout impairs lipid secretion and exacerbates hepatic steatosis. Significantly, the expression of metabolism molecules BSEP increased, while NTCP and CYP7A1 decreased following rifampicin administration in C57BL/6N mice, whereas these changes were absent in FXR knockout mice. Furthermore, rifampicin treatment in both C57BL/6N and FXR-null mice was associated with elevated c-Jun N-terminal kinase phosphorylation (p-JNK) levels, with a more pronounced elevation in FXR-null mice. Our study suggests that rifampicin-induced liver injury, steatosis, and cholestasis are associated with FXR dysfunction and altered bile acid metabolism, and that the JNK signaling pathway is partially implicated in this injury. Based on these results, we propose that FXR might be a novel therapeutic target for addressing drug-induced liver injury.
Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas , Hígado , Ratones Endogámicos C57BL , Ratones Noqueados , Receptores Citoplasmáticos y Nucleares , Rifampin , Animales , Rifampin/efectos adversos , Receptores Citoplasmáticos y Nucleares/metabolismo , Receptores Citoplasmáticos y Nucleares/genética , Enfermedad Hepática Inducida por Sustancias y Drogas/tratamiento farmacológico , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Hígado/patología , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Ratones , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/genética , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/metabolismo , Colesterol 7-alfa-Hidroxilasa/genética , Colesterol 7-alfa-Hidroxilasa/metabolismo , Simportadores/genética , Simportadores/metabolismo , Ácidos y Sales Biliares/metabolismo , Transportadores de Anión Orgánico Sodio-Dependiente/genética , Transportadores de Anión Orgánico Sodio-Dependiente/metabolismo , Colestasis/inducido químicamente , Colestasis/tratamiento farmacológico , Colestasis/metabolismo , Hígado Graso/tratamiento farmacológico , Hígado Graso/inducido químicamente , Hígado Graso/metabolismo , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismoRESUMEN
The BSEP/ABCB11 transmembrane protein translocates taurine- and glycine-conjugated bile salts across the hepatocyte bilayer driven by ATP-hydrolysis. Direct inhibition of BSEP/ABCB11 leads to idiosyncratic drug-induced liver injury. ABCB11 is localized within the cholesterol-enriched lipid raft, and membrane cholesterol depletion leads to impaired taurocholate transport. However, structural insight into the mechanism of the cholesterol-mediated regulation of ABCB11 activity remains elusive. We used extensive molecular dynamics simulation coupled with well-tempered metadynamics to elucidate the role of membrane cholesterol in the structure and dynamics of ABCB11. We identified specific high-residence binding sites for cholesterol within the transmembrane domain. The free-energy simulations have elucidated that the bound cholesterol stabilizes the "inward-open" conformation of the protein. Cholesterol-ABCB11 interactions trigger allosteric communications between the transmembrane and nucleotide-binding domains through the linker region. Cholesterol depletion destabilizes the allosteric network of the protein. As a result, it adopts a more collapsed form with a reduced volume of the taurocholate-binding pocket.
Asunto(s)
Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP , Colesterol , Ácido Taurocólico , Humanos , Regulación Alostérica , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/metabolismo , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/química , Transportadoras de Casetes de Unión a ATP/metabolismo , Transportadoras de Casetes de Unión a ATP/química , Sitios de Unión , Colesterol/química , Colesterol/metabolismo , Simulación de Dinámica Molecular , Ácido Taurocólico/química , Ácido Taurocólico/metabolismo , TermodinámicaRESUMEN
AIMS: Estradiol 17ß-d-glucuronide (E217G) induces cholestasis by triggering endocytosis and further intracellular retention of the canalicular transporters Bsep and Mrp2, in a cPKC- and PI3K-dependent manner, respectively. Pregnancy-induced cholestasis has been associated with E217G cholestatic effect, and is routinely treated with ursodeoxycholic acid (UDCA). Since protective mechanisms of UDCA in E217G-induced cholestasis are still unknown, we ascertained here whether its main metabolite, tauroursodeoxycholate (TUDC), can prevent endocytosis of canalicular transporters by counteracting cPKC and PI3K/Akt activation. MAIN METHODS: Activation of cPKC and PI3K/Akt was evaluated in isolated rat hepatocytes by immunoblotting (assessment of membrane-bound and phosphorylated forms, respectively). Bsep/Mrp2 function was quantified in isolated rat hepatocyte couplets (IRHCs) by assessing the apical accumulation of their fluorescent substrates, CLF and GS-MF, respectively. We also studied, in isolated, perfused rat livers (IPRLs), the status of Bsep and Mrp2 transport function, assessed by the biliary excretion of TC and DNP-SG, respectively, and Bsep/Mrp2 localization by immunofluorescence. KEY FINDINGS: E217G activated both cPKC- and PI3K/Akt-dependent signaling, and pretreatment with TUDC significantly attenuated these activations. In IRHCs, TUDC prevented the E217G-induced decrease in apical accumulation of CLF and GS-MF, and inhibitors of protein phosphatases failed to counteract this protection. In IPRLs, E217G induced an acute decrease in bile flow and in the biliary excretion of TC and DNP-SG, and this was prevented by TUDC. Immunofluorescence studies revealed that TUDC prevented E217G-induced Bsep/Mrp2 endocytosis. SIGNIFICANCE: TUDC restores function and localization of Bsep/Mrp2 impaired by E217G, by preventing both cPKC and PI3K/Akt activation in a protein-phosphatase-independent manner.
Asunto(s)
Colestasis , Endocitosis , Estradiol , Hepatocitos , Fosfatidilinositol 3-Quinasas , Transducción de Señal , Ácido Tauroquenodesoxicólico , Animales , Colestasis/metabolismo , Colestasis/inducido químicamente , Colestasis/prevención & control , Ratas , Transducción de Señal/efectos de los fármacos , Estradiol/metabolismo , Estradiol/farmacología , Estradiol/análogos & derivados , Hepatocitos/metabolismo , Hepatocitos/efectos de los fármacos , Endocitosis/efectos de los fármacos , Ácido Tauroquenodesoxicólico/farmacología , Ácido Tauroquenodesoxicólico/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas Wistar , Femenino , Masculino , Proteína Quinasa C/metabolismo , Transportadoras de Casetes de Unión a ATP/metabolismoRESUMEN
Obesity is associated with alterations in lipid metabolism and gut microbiota dysbiosis. This study investigated the effects of puerarin, a bioactive isoflavone, on lipid metabolism disorders and gut microbiota in high-fat diet (HFD)-induced obese mice. Supplementation with puerarin reduced plasma alanine aminotransferase, liver triglyceride, liver free fatty acid (FFA), and improved gut microbiota dysbiosis in obese mice. Puerarin's beneficial metabolic effects were attenuated when farnesoid X receptor (FXR) was antagonized, suggesting FXR-mediated mechanisms. In hepatocytes, puerarin ameliorated high FFA-induced sterol regulatory element-binding protein (SREBP) 1 signaling, inflammation, and mitochondrial dysfunction in an FXR-dependent manner. In obese mice, puerarin reduced liver damage, regulated hepatic lipogenesis, decreased inflammation, improved mitochondrial function, and modulated mitophagy and ubiquitin-proteasome pathways, but was less effective in FXR knockout mice. Puerarin upregulated hepatic expression of FXR, bile salt export pump (BSEP), and downregulated cytochrome P450 7A1 (CYP7A1) and sodium taurocholate transporter (NTCP), indicating modulation of bile acid synthesis and transport. Puerarin also restored gut microbial diversity, the Firmicutes/Bacteroidetes ratio, and the abundance of Clostridium celatum and Akkermansia muciniphila. This study demonstrates that puerarin effectively ameliorates metabolic disturbances and gut microbiota dysbiosis in obese mice, predominantly through FXR-dependent pathways. These findings underscore puerarin's potential as a therapeutic agent for managing obesity and enhancing gut health, highlighting its dual role in improving metabolic functions and modulating microbial communities.
Asunto(s)
Dieta Alta en Grasa , Microbioma Gastrointestinal , Isoflavonas , Hígado , Obesidad , Receptores Citoplasmáticos y Nucleares , Animales , Isoflavonas/farmacología , Microbioma Gastrointestinal/efectos de los fármacos , Dieta Alta en Grasa/efectos adversos , Receptores Citoplasmáticos y Nucleares/metabolismo , Ratones , Obesidad/metabolismo , Obesidad/tratamiento farmacológico , Hígado/metabolismo , Hígado/efectos de los fármacos , Masculino , Disbiosis , Ratones Obesos , Ratones Endogámicos C57BL , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/metabolismo , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/genética , Colesterol 7-alfa-Hidroxilasa/metabolismo , Colesterol 7-alfa-Hidroxilasa/genética , Ratones Noqueados , Transportadores de Anión Orgánico Sodio-Dependiente/metabolismo , Transportadores de Anión Orgánico Sodio-Dependiente/genética , Simportadores/metabolismo , Simportadores/genética , Metabolismo de los Lípidos/efectos de los fármacos , Hepatocitos/metabolismo , Hepatocitos/efectos de los fármacos , AkkermansiaRESUMEN
Cholestasis is characterized by hepatic accumulation of bile acids. Clinical manifestation of cholestasis only occurs in a small proportion of exposed individuals. The present study aims to develop a new approach methodology (NAM) to predict drug-induced cholestasis as a result of drug-induced hepatic bile acid efflux inhibition and the resulting bile acid accumulation. To this end, hepatic concentrations of a panel of drugs were predicted by a generic physiologically based kinetic (PBK) drug model. Their effects on hepatic bile acid efflux were incorporated in a PBK model for bile acids. The predicted bile acid accumulation was used as a measure for a drug's cholestatic potency. The selected drugs were known to inhibit hepatic bile acid efflux in an assay with primary suspension-cultured hepatocytes and classified as common, rare, or no for cholestasis incidence. Common cholestasis drugs included were atorvastatin, chlorpromazine, cyclosporine, glimepiride, ketoconazole, and ritonavir. The cholestasis incidence of the drugs appeared not to be adequately predicted by their Ki for inhibition of hepatic bile acid efflux, but rather by the AUC of the PBK model predicted internal hepatic drug concentration at therapeutic dose level above this Ki. People with slower drug clearance, a larger bile acid pool, reduced bile salt export pump (BSEP) abundance, or given higher than therapeutic dose levels were predicted to be at higher risk to develop drug-induced cholestasis. The results provide a proof-of-principle of using a PBK-based NAM for cholestasis risk prioritization as a result of transporter inhibition and identification of individual risk factors.
Asunto(s)
Ácidos y Sales Biliares , Colestasis , Hepatocitos , Modelos Biológicos , Colestasis/inducido químicamente , Colestasis/metabolismo , Humanos , Ácidos y Sales Biliares/metabolismo , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Medición de Riesgo , Hígado/metabolismo , Hígado/efectos de los fármacos , Células Cultivadas , Enfermedad Hepática Inducida por Sustancias y Drogas , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/metabolismo , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/antagonistas & inhibidoresRESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: Dan-shen Yin (DSY), a traditional prescription, has been demonstrated to be effective in decreasing hyperlipidemia and preventing atherosclerosis (AS), but its mechanism remains unknown. We hypothesized that DSY activates farnesoid X receptor (FXR) to promote bile acid metabolism and excretion, thereby alleviating AS. AIM OF THE STUDY: This study was designed to explore whether DSY reduces liver lipid accumulation and prevents AS by activating FXR and increasing cholesterol metabolism and bile acid excretion. MATERIALS AND METHODS: The comprehensive chemical characterization of DSY was analyzed by UHPLC-MS/MS. The AS models of ApoE-/- mice and SD rats was established by high-fat diet and high-fat diet combined with intraperitoneal injection of vitamin D3, respectively. The aortic plaque and pathological changes were used to evaluate AS. Lipid levels, H&E staining and oil red O staining were used to evaluate liver lipid accumulation. The cholesterol metabolism and bile acid excretion were evaluated by enzyme-linked immunosorbent assay, UPLC-QQQ/MS. In vitro, the lipid and FXR/bile salt export pump (BSEP) levels were evaluated by oil red O staining, real-time quantitative polymerase chain reaction (RT-qPCR) and western blotting. RESULTS: A total of 36 ingredients in DSY were identified by UPLC-MS/MS analysis. In vivo, high-dose DSY significantly inhibited aortic intimal thickening, improved arrangement disorder, tortuosity, and rupture of elastic fibers, decreased lipid levels, and reduced the number of fat vacuoles and lipid droplets in liver tissue in SD rats and ApoE-/- mice. Further studies found that high-dose DSY significantly reduced liver lipid and total bile acids levels, increased liver ursodeoxycholic acid (UDCA) and other non-conjugated bile acids levels, increased fecal total cholesterol (TC) levels, and augmented FXR, BSEP, cholesterol 7-alpha hydroxylase (CYP7A1), ATP binding cassette subfamily G5/G8 (ABCG5/8) expression levels, while decreasing ASBT expression levels. In vitro studies showed that DSY significantly reduced TC and TG levels, as well as lipid droplets, while also increasing the expression of ABCG5/8, FXR, and BSEP in both HepG2 and Nr1h4 knockdown HepG2 cells. CONCLUSION: This study demonstrated that DSY promotes bile acid metabolism and excretion to prevent AS by activating FXR. For the prevent of AS and drug discovery provided experimental basis.
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Aterosclerosis , Ácidos y Sales Biliares , Medicamentos Herbarios Chinos , Transducción de Señal , Animales , Humanos , Masculino , Ratones , Ratas , Aterosclerosis/prevención & control , Aterosclerosis/metabolismo , Aterosclerosis/tratamiento farmacológico , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/metabolismo , Ácidos y Sales Biliares/metabolismo , Dieta Alta en Grasa/efectos adversos , Medicamentos Herbarios Chinos/farmacología , Metabolismo de los Lípidos/efectos de los fármacos , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Ratones Endogámicos C57BL , Ratones Noqueados para ApoE , Ratas Sprague-Dawley , Receptores Citoplasmáticos y Nucleares/metabolismo , Transducción de Señal/efectos de los fármacosRESUMEN
The bile salt export pump (ABCB11/BSEP) is a hepatocyte plasma membrane-resident protein translocating bile salts into bile canaliculi. The sequence alignment of the four full-length transporters of the ABCB subfamily (ABCB1, ABCB4, ABCB5 and ABCB11) indicates that the NBD-NBD contact interface of ABCB11 differs from that of other members in only four residues. Notably, these are all located in the noncanonical nucleotide binding site 1 (NBS1). Substitution of all four deviant residues with canonical ones (quadruple mutant) significantly decreased the transport activity of the protein. In this study, we mutated two deviant residues in the signature sequence to generate a double mutant (R1221G/E1223Q). Furthermore, a triple mutant (E502S/R1221G/E1223Q) was generated, in which the deviant residues of the signature sequence and Q-loop were mutated concurrently to canonical residues. The double and triple mutants showed 80% and 60%, respectively, of the activity of wild-type BSEP. As expected, an increasing number of mutations gradually impair transport as an intricate network of interactions within the ABC proteins ensures proper functioning.
Asunto(s)
Transportadoras de Casetes de Unión a ATP , Nucleótidos , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/genética , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/metabolismo , Nucleótidos/metabolismo , Transportadoras de Casetes de Unión a ATP/genética , Transportadoras de Casetes de Unión a ATP/metabolismo , Mutación/genética , Sitios de UniónRESUMEN
BACKGROUND AND AIMS: The secretion of bile salts transported by the bile salt export pump (BSEP) is the primary driving force for the generation of bile flow; thus, it is closely related to the formation of cholesterol stones. Caveolin-1 (Cav-1), an essential player in cell signalling and endocytosis, is known to co-localize with cholesterol-rich membrane domains. This study illustrates the role of Cav-1 and BSEP in cholesterol stone formation. METHODS: Adult male C57BL/6 mice were used as an animal model. HepG2 cells were cultured under different cholesterol concentrations and BSEP, Cav-1, p-PKCα and Hax-1 expression levels were determined via Western blotting. Expression levels of BSEP and Cav-1 mRNA were detected using real-time PCR. Immunofluorescence and immunoprecipitation assays were performed to study BSEP and Hax-1 distribution. Finally, an ATPase activity assay was performed to detect BSEP transport activity under different cholesterol concentrations in cells. RESULTS: Under low-concentration stimulation with cholesterol, Cav-1 and BSEP protein and mRNA expression levels significantly increased, PKCα phosphorylation significantly decreased, BSEP binding capacity to Hax-1 weakened, and BSEP function increased. Under high-concentration stimulation with cholesterol, Cav-1 and BSEP protein and mRNA expression levels decreased, PKCα phosphorylation increased, BSEP binding capacity to Hax-1 rose, and BSEP function decreased. CONCLUSION: Cav-1 regulates the bile salt export pump on the canalicular membrane of hepatocytes via PKCα-associated signalling under cholesterol stimulation.
Asunto(s)
Caveolina 1 , Proteína Quinasa C-alfa , Animales , Masculino , Ratones , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/metabolismo , Transportadoras de Casetes de Unión a ATP/genética , Ácidos y Sales Biliares/metabolismo , Caveolina 1/metabolismo , Colesterol/metabolismo , Hepatocitos/metabolismo , Ratones Endogámicos C57BL , Proteína Quinasa C-alfa/metabolismo , ARN Mensajero/metabolismo , HumanosRESUMEN
Ursolic acid (UA), a pentacyclic triterpenoid, exhibits various pharmacological actions, such as anti-inflammation, anti-tumor, anti-diabetes, heart protection, and liver protection. However, the role of nuclear factor E2-related factor 2 (NRF2)-mediated regulation of uridine diphosphate glucuronosyltransferase (UGT2B7) and bile salt export pump (BSEP)/multidrug resistance-associated protein 2 (MRP2) in UA against cholestatic liver injury has not been cleared. The purpose of this study is to explore the effect of UA on cholestatic liver injury and its potential mechanism. The results of the liver pathology sections and blood biochemical indices demonstrated that UA significantly attenuated the cholestatic liver injury induced by alpha-naphthylisothiocyanate (ANIT) in a dose-dependent manner. The mRNA and protein levels of UGT2B7 and BSEP/MRP2 were remarkably increased in the liver of ANIT rats and HepG2 cells pretreated with UA, but this activation was suppressed with NRF2 silenced. In conclusion, our findings demonstrate that UA prevents cholestasis, which may be associated with NRF2-mediated regulation of UGT2B7, BSEP/MRP2.
Asunto(s)
Colestasis , Proteína 2 Asociada a Resistencia a Múltiples Medicamentos , Ratas , Animales , Ácido Ursólico , Factor 2 Relacionado con NF-E2/metabolismo , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/metabolismo , Colestasis/tratamiento farmacológico , HígadoRESUMEN
The abnormal increase of Oddi sphincter pressure and total bile duct pressure may play an important role in the formation of cholesterol stones, but the specific molecular mechanism is still unclear. This study aims to investigate it through in vitro and in vivo experiments. A mouse model of Oddi sphincter dysfunction was constructed by stone-inducing diet. We compared the two groups with PKC-α inhibitor GÖ6976 and PKC-α agonist thymeleatoxin. Oddi sphincter pressure and total bile duct pressure were measured. Biochemical analysis of total cholesterol, bile acid and bilirubin was then conducted. The histopathologic changes of bile duct were observed by HE staining and the ultrastructure of liver cells and surrounding tissues was observed by transmission electron microscopy. Through the above experiments, we found that the change of PKC-α expression may affect the formation process of gallstones. The relationship between PKC-α and ABCB11 was further verified by in vitro and in vivo experiments. Our results suggest that ABCB11 and PKC-α are co-expressed in the tubule membrane of hepatocytes and interact with each other in hepatocytes. The high cholesterol diet further enhances the activation of PKC-α and thus reduces the expression of ABCB11. The formation of cholesterol stones is associated with the down-regulation of ABCB11 expression in the tubule membrane of hepatocytes due to kinase signaling. This is the first study to demonstrate that sphincter of Oddi dysfunction induces gallstones through PKC-α inhibition of ABCB11 expression.
Asunto(s)
Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP , Cálculos Biliares , Proteína Quinasa C-alfa , Esfínter de la Ampolla Hepatopancreática , Animales , Ratones , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/metabolismo , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/genética , Colesterol/metabolismo , Cálculos Biliares/metabolismo , Hepatocitos/metabolismo , Hepatocitos/efectos de los fármacos , Ratones Endogámicos C57BL , Proteína Quinasa C-alfa/metabolismo , Esfínter de la Ampolla Hepatopancreática/metabolismo , FemeninoRESUMEN
The aim of this study was to determine the effect of tauroursodeoxycholic acid (TUDCA) on the alpha-naphthylisothiocyanate (ANIT)-induced model of cholestasis in mice. Wild-type and farnesoid X receptor (FXR)-deficient (Fxr-/- ) mice were used to generate cholestasis models by gavage with ANIT. Obeticholic acid (OCA) was used as a positive control. In wild-type mice, treatment with TUDCA for 7 days resulted in a dramatic increase in serum levels of alanine aminotransferase (ALT), with aggravation of bile infarcts and hepatocyte necrosis with ANIT-induction. TUDCA activated FXR to upregulate the expression of bile salt export pump (BSEP), increasing bile acids (BAs)-dependent bile flow, but aggravating cholestatic liver injury when bile ducts were obstructed resulting from ANIT. In contrast, TUDCA improved the liver pathology and decreased serum ALT and alkaline phosphatase (ALP) levels in ANIT-induced Fxr-/- mice. Furthermore, TUDCA inhibited the expression of cleaved caspase-3 and reduced the area of terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining in the model mice. TUDCA also upregulated anion exchanger 2 (AE2) protein expression, protecting cholangiocytes against excessive toxic BAs. Our results showed that TUDCA aggravated cholestatic liver injury via the FXR/BSEP pathway when bile ducts were obstructed, although TUDCA inhibited apoptotic activity and protected cholangiocytes against excessive toxic BAs.
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Colagogos y Coleréticos , Colestasis , Ratones , Animales , Colagogos y Coleréticos/efectos adversos , Colagogos y Coleréticos/metabolismo , 1-Naftilisotiocianato/toxicidad , 1-Naftilisotiocianato/metabolismo , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/metabolismo , Receptores Citoplasmáticos y Nucleares/genética , Receptores Citoplasmáticos y Nucleares/metabolismo , Hígado , Colestasis/inducido químicamente , Ácidos y Sales Biliares/metabolismoRESUMEN
This study focused on the preventive effects of the extracts of Rhus chinensis Mill. (RCM) fruits on cholestasis induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) in mice. The results showed that RCM extracts could significantly ameliorate DDC-induced cholestasis via multiple mechanisms, including (1) alleviating liver damage via enhancing antioxidant capacity, such as increasing the contents of glutathione, superoxide dismutase, and catalase and inhibiting the levels of malondialdehyde; (2) preventing liver inflammation by suppressing NF-κB pathway and reducing proinflammatory cytokines secretion (e.g., tumor necrosis factor-α, interleukin-1ß, and interleukin-6); (3) inhibiting liver fibrosis and collagen deposition by regulating the expression of transforming growth factor-ß and α-smooth muscle actin; (4) modulating abnormal bile acid metabolism through increasing the expression of bile salt export pump and multidrug resistance-associated protein 2. This study was the first to elucidate the potential preventive effect of RCM extracts on DDC-induced cholestasis in mice from multiple pathways, which suggested that RCM fruits could be considered as a potential dietary supplement to prevent cholestasis.
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Colestasis , Extractos Vegetales , Rhus , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/metabolismo , Actinas/metabolismo , Animales , Antioxidantes/metabolismo , Ácidos y Sales Biliares/metabolismo , Catalasa/metabolismo , Colestasis/inducido químicamente , Colestasis/prevención & control , Colágeno/metabolismo , Frutas/metabolismo , Glutatión/metabolismo , Inflamación/inducido químicamente , Inflamación/metabolismo , Inflamación/prevención & control , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Hígado/metabolismo , Malondialdehído/metabolismo , Ratones , FN-kappa B/metabolismo , Estrés Oxidativo , Extractos Vegetales/farmacología , Piridinas/efectos adversos , Superóxido Dismutasa/metabolismo , Factores de Crecimiento Transformadores/metabolismo , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
PURPOSE: IR injury is an unavoidable consequence in deceased donor liver transplantation. Cold preservation and warm reperfusion may change the expression and function of drug transporters in the liver due to vasoconstriction, infiltration of neutrophils and release of cytokines. We hypothesize that vasodilation, anti-platelet aggregation and proinflammatory downregulation activities of treprostinil will diminish the IR injury and its associated effects. METHODS: Livers obtained from male SD rats (n = 20) were divided into 1) Control, 2) IR, 3) Treprostinil-1 (preservation only), and 4) Treprostinil-2 (preservation and reperfusion) groups. Control livers were procured and immediately reperfused. Livers in the other groups underwent preservation for 24 h and were reperfused. All the livers were perfused using an Isolated Perfused Rat Liver (IPRL) system. Periodic perfusate, cumulative bile samples and liver tissue at the end of perfusion were collected. Liver injury markers, bile flow rates, m-RNA levels for uptake and efflux transporters (qRT-PCR) were measured. RESULTS: Cold preservation and warm reperfusion significantly increased the release of AST and ALT in untreated livers. Treprostinil supplementation substantially reduced liver injury. Bile flow rate was significantly improved in treprostinil-2 group. m-RNA levels of Slc10a1, Slc22a1, and Slc22a7 in liver were increased and m-RNA levels of Mdr1a were decreased by IR. Treprostinil treatment increased Abcb11 and Abcg2 m-RNA levels and maintained Slc22a1m-RNA similar to control livers. CONCLUSIONS: Treprostinil treatment significantly reduced liver injury. IR injury changed expression of both uptake and efflux transporters in rat livers. Treprostinil significantly altered the IR injury mediated changes in m-RNA expression of transporters.
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Trasplante de Hígado , Daño por Reperfusión , Animales , Masculino , Ratas , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/metabolismo , Suplementos Dietéticos , Hígado/metabolismo , Donadores Vivos , Preservación de Órganos , Ratas Sprague-Dawley , Daño por Reperfusión/tratamiento farmacológico , Daño por Reperfusión/prevención & control , Daño por Reperfusión/metabolismo , ARN/metabolismo , ARN/farmacologíaRESUMEN
Cholesterol gallstone (CGS) disease is characterized by an imbalance in bile acid (BA) metabolism and is closely associated with gut microbiota disorders. However, the role and mechanism by which probiotics targeting the gut microbiota attenuate cholesterol gallstones are still unknown. In this study, Limosilactobacillus reuteri strain CGMCC 17942 and Lactiplantibacillus plantarum strain CGMCC 14407 were individually administered to lithogenic-diet (LD)-fed mice for 8 weeks. Both Lactobacillus strains significantly reduced LD-induced gallstones, hepatic steatosis, and hyperlipidemia. These strains modulated BA profiles in the serum and liver, which may be responsible for the activation of farnesoid X receptor (FXR). At the molecular level, L. reuteri and L. plantarum increased ileal fibroblast growth factor 15 (FGF15) and hepatic fibroblast growth factor receptor 4 (FGFR4) and small heterodimer partner (SHP). Subsequently, hepatic cholesterol 7α-hydroxylase (CYP7A1) and oxysterol 7α-hydroxylase (CYP7B1) were inhibited. Moreover, the two strains enhanced BA transport by increasing the levels of hepatic multidrug resistance-associated protein homologs 3 and 4 (Mrp3/4), hepatic multidrug resistance protein 2 (Mdr2), and the bile salt export pump (BSEP). In addition, both L. reuteri and L. plantarum reduced LD-associated gut microbiota dysbiosis. L. reuteri increased the relative abundance of Muribaculaceae, while L. plantarum increased that of Akkermansia. The changed gut microbiota was significantly negatively correlated with the incidence of cholesterol gallstones and the FXR-antagonistic BAs in the liver and serum and with the FXR signaling pathways. Furthermore, the protective effects of the two strains were abolished by both global and intestine-specific FXR antagonists. These findings suggest that Lactobacillus might relieve CGS through the FXR signaling pathways. IMPORTANCE Cholesterol gallstone (CGS) disease is prevalent worldwide. None of the medical options for prevention and treatment of CGS disease are recommended, and surgical management has a high rate of recurrence. It has been reported that the factors involved in metabolic syndrome are highly connected with CGS formation. While remodeling of dysbiosis of the gut microbiome during improvement of metabolic syndrome has been well studied, less is known about prevention of CGS formation after regulating the gut microbiome. We used the lithogenic diet (LD) to induce an experimental CGS model in C57BL/6J mice to investigate protection against CGS formation by Limosilactobacillus reuteri strain CGMCC 17942 and Lactiplantibacillus plantarum strain CGMCC 14407. We found that these L. reuteri and L. plantarum strains altered the bile acid composition in mice and improved the dysbiosis of the gut microbiome. These two Lactobacillus strains prevented CGS formation by fully activating the hepatic and ileal FXR signaling pathways. They could be a promising therapeutic strategy for treating CGS or preventing its recurrence.
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Cálculos Biliares , Síndrome Metabólico , Oxiesteroles , Ratones , Animales , Colesterol 7-alfa-Hidroxilasa/metabolismo , Cálculos Biliares/metabolismo , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/metabolismo , Receptor Tipo 4 de Factor de Crecimiento de Fibroblastos/metabolismo , Lactobacillus/metabolismo , Disbiosis , Síndrome Metabólico/metabolismo , Ratones Endogámicos C57BL , Ácidos y Sales Biliares/metabolismo , Hígado/metabolismo , Factores de Crecimiento de Fibroblastos/metabolismo , Colesterol/metabolismo , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/metabolismo , Oxiesteroles/metabolismoRESUMEN
Objective: Rifampicin (RFP) induces cholestasis due to long-term tubercular therapy. Impairment of the canalicular bile acids efflux via the bile salt export pump (BSEP) is a well-recognized cause of cholestasis. Tanshinone IIA (TAN IIA) has a protective effect on the liver. However, there are limited studies on the effects of RFP and TAN IIA on BSEP. In present study, we aimed to elucidate the effects of RFP and TAN IIA on BSEP and provide evidence to support the treatment of RFP-induced cholestasis with TAN IIA. Methods: Firstly, liver histopathological examination and serum biochemical tests were evaluated in rats. Secondly, we evaluated BSEP expression by qRT-PCR and western blotting to explore whether RFP and TAN IIA influence liver function through BSEP. Thirdly, the accumulation of BSEP substrate taurocholic acid (TCA) in bile ducts was determined to investigate the effects of RFP and TAN IIA on BSEP function. Results: Apparent histopathological alterations and significantly increased serum biomarkers were observed in the RFP group (200 mg/kg), while these changes were attenuated in the combination groups. The mRNA and protein levels of BSEP were decreased by RFP. Whereas TAN IIA reversed the downward regulation of BSEP caused by RFP. And RFP primarily inhibited TCA excretion but co-administration of TAN IIA markedly induced TCA excretion mediated by BSEP. Conclusion: Our findings collectively demonstrated that RFP-induced cholestasis could be related to the inhibition of BSEP, and TAN IIA had the potential to prevent RFP-induced cholestasis by regulating BSEP.
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Abietanos , Colestasis , Rifampin , Animales , Ratas , Abietanos/farmacología , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/genética , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/metabolismo , Ácidos y Sales Biliares/metabolismo , Colestasis/inducido químicamente , Colestasis/tratamiento farmacológico , Hígado , Rifampin/toxicidad , Ácido Taurocólico/metabolismoRESUMEN
BACKGROUND: Non-alcoholic steatohepatitis (NASH) can develop into cirrhosis, liver failure, or hepatocellular carcinoma without effective treatment. However, there are currently no drugs for NASH treatment, and the development of new therapeutics has remained a major challenge in NASH research. Advances in traditional Chinese medicine to treat liver disease inspired us to search for new NASH candidates from Chi-Shao, a widely used traditional Chinese medicine. PURPOSE: In this research, we aimed to clarify the anti-NASH effect and the underlying mechanism of isopropylidenyl anemosapogenin (IA, 1), which was a new lead compound isolated from Chi-Shao. STUDY DESIGN AND METHODS: Isopropylidenyl anemosapogenin (IA, 1) was first discovered by collagen type I α 1 promoter luciferase bioassay-guided isolation and then characterized by single crystal X-ray diffraction analysis and enriched by semi-synthesis. Using various molecular biology techniques, the multiple anti-NASH efficacies and mechanisms of IA were clarified based on in vitro LX-2 and Huh7 cell models, along with the in vivo choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD)-induced mouse model and bile duct ligation (BDL)-induced rat model. The UPLC-MS/MS method was used to assess the plasma concentration of IA. RESULTS: A new lead compound IA was isolated from the traditional Chinese medicine Chi-Shao, which showed significant anti-liver fibrosis activity in TGF-ß1-treated LX-2 cells and anti-liver steatosis activity in oleic acid-treated Huh7 cells. Furthermore, IA could significantly ameliorate in vivo CDAHFD-induced liver injury by activating the farnesoid X receptor pathway, including its targets Nr0b2, Abcb11, and Slc10a2. Simultaneously, IA activated the autophagy pathway by activating the TFEB factor, thereby promoting lipid degradation. Its liver-protective and anti-fibrosis activities were verified by the BDL-induced rat model. Finally, with an oral administration of 100 mg/kg, IA achieved the maximum plasma concentration of 1.23 ± 0.18 µg/ml at 2.67 ± 0.58 h. CONCLUSION: IA, an unreported lupine-type triterpenoid isolated from Chi-shao, can significantly alleviate liver injury and fibrosis via farnesoid X receptor activation and TFEB-mediated autophagy, which indicates that IA could serve as a novel therapeutic candidate against NASH.
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Neoplasias Hepáticas , Enfermedad del Hígado Graso no Alcohólico , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/metabolismo , Animales , Autofagia , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/metabolismo , Cromatografía Liquida , Modelos Animales de Enfermedad , Fibrosis , Hígado , Cirrosis Hepática/metabolismo , Neoplasias Hepáticas/patología , Ratones , Ratones Endogámicos C57BL , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Ratas , Espectrometría de Masas en TándemRESUMEN
In this study, the inhibitory effect of components from Chinese Herb Medicine (CHMs) with potential hepatotoxicity was assessed by human bile salt export pump (hBSEP) vesicles with and without S9 metabolism. Sixty-three compounds from 22 hepatoxicity CHMs were selected as the test articles. In hBSEP vesicles, eighteen of them were found to have moderate or strong inhibitory effect towards BSEP. Further studies were performed to determine the IC50 values of strong inhibitors. For the compounds belong to CHMs reported to cause cholestasis and strong inhibitors defined in hBSEP vesicles, their relative transport activities of Taurocholic acid (TCA) were evaluated in hBSEP vesicles as well as hBSEP vesicles with S9 system (S9/hBSEP vesicles). The differences of their relative transport activities of TCA between the above two system were compared to reveal the net effect of metabolism on BSEP's activity. It was found that the inhibitory effect of Saikogenin A (SGA), Saikogenin D (SGD), Diosbulbin B (DB) and rhein were significantly increased; while the inhibitory effect of isobavachalcone, saikosaponin d and saikosaponin b2 were significantly decreased after S9 metabolizing. Identification of metabolic pathways suggested that CYP3A4 was responsible for aggravating inhibitory effect of SGA and SGD against BSEP.
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Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/antagonistas & inhibidores , Medicamentos Herbarios Chinos/toxicidad , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/genética , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/metabolismo , Colestasis/metabolismo , Humanos , Hígado/metabolismoRESUMEN
BACKGROUND AND AIMS: Lipopolysaccharide (LPS) clearance is delayed in cholestatic liver diseases. While compromised clearance by Kupffer cells (KCs) is involved, the role of LPS uptake into hepatocytes and canalicular excretion remains unclear. APPROACH AND RESULTS: Wild-type (WT) and bile salt export pump (Bsep) knockout (KO) mice were challenged i.p. with LPS. Liver injury was assessed by serum biochemistry, histology, molecular inflammation markers, and immune cell infiltration. LPS concentrations were determined in liver tissue and bile. Subcellular kinetics of fluorescently labeled LPS was visualized by intravital two-photon microscopy, and the findings in Bsep KO mice were compared to common bile duct-ligated (BDL) and multidrug resistance protein 2 (Mdr2) KO mice. Changes in gut microbiota composition were evaluated by 16S ribosomal RNA gene amplicon sequencing analysis. Bsep KO mice developed more pronounced LPS-induced liver injury and inflammatory signaling, with subsequently enhanced production of proinflammatory cytokines and aggravated hepatic immune cell infiltration. After LPS administration, its concentrations were higher in liver but lower in bile of Bsep KO compared to WT mice. Intravital imaging of LPS showed a delayed clearance from sinusoidal blood with a basolateral uptake block into hepatocytes and reduced canalicular secretion. Moreover, LPS uptake into KCs was reduced. Similar findings with respect to hepatic LPS clearance were obtained in BDL and Mdr2 KO mice. Pretreatment with the microtubule inhibitor colchicine inhibited biliary excretion of LPS in WT mice, indicating that LPS clearance is microtubule-dependent. Microbiota analysis showed no change of the gut microbiome between WT and Bsep KO mice at baseline but major changes upon LPS challenge in WT mice. CONCLUSIONS: Absence of Bsep and cholestasis in general impair LPS clearance by a basolateral uptake block into hepatocytes and consequently less secretion into canaliculi. Impaired LPS removal aggravates hepatic inflammation in cholestasis.
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Enfermedad Hepática Crónica Inducida por Sustancias y Drogas , Colestasis , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/metabolismo , Animales , Ácidos y Sales Biliares/metabolismo , Colestasis/patología , Endotoxinas , Inflamación/metabolismo , Cinética , Lipopolisacáridos/metabolismo , Hígado/patología , Ratones , Ratones NoqueadosRESUMEN
SCOPE: Aspergillus terreus is an industrial microorganism used in the brewing and sauce industries. It produces monacolin K, a natural statin. The study conducted an 8-week randomized controlled trial with hypercholesterolemic subjects to examine the hypocholesterolemic effects and mechanisms of supplementation with yellow yeast rice (YYR) prepared by growing Aspergillus fungi on steamed rice. METHODS AND RESULTS: YYR supplementation markedly reduced total cholesterol, LDL, and apolipoprotein B100 levels in plasma compared with the placebo. In addition, YYR induced a significantly increased ATP binding cassette subfamily B member 11 (ABCB11) gene expression compared with the placebo, indicating the role of YYR in lowering intrahepatic cholesterol availability by stimulating the bile salt export pump. Upregulation of LDL receptor (LDLR) and 3-methylglutaryl-CoA reductase (HMGCR) gene expressions provided additional evidence to support the role of YYR in reducing hepatic cholesterol availability. Plasma metabolomic profiling revealed the possibility of diminishing bile acid absorption. Finally, Spearman rank analysis showed correlations of plasma cholesterol profiles with HMGCR and LDLR gene expressions (negative) and plasma bile acids (positive). Plasma bile acids also correlated with ABCB11 (negative) and LDLR (positive) gene expressions. CONCLUSION: These findings suggest that daily YYR supplementation exerted hypocholesterolemic effects in mild-to-moderate hypercholesterolemic subjects by reducing intrahepatic cholesterol availability through stimulating bile salt export pumps and inhibiting cholesterol biosynthesis.