Background Farnesoid X receptor(FXR)has been identified as a therapeutic target for metabolic dysfunction-associated steatohepatitis(MASH).Hepatic FXR is especially critical in suppressing liver inflammation.FXR agoni...Background Farnesoid X receptor(FXR)has been identified as a therapeutic target for metabolic dysfunction-associated steatohepatitis(MASH).Hepatic FXR is especially critical in suppressing liver inflammation.FXR agonism and antagonism have both proven to be beneficial in the mitigation of MASH,leading to much controversy in the field,particularly regarding FXR signalling in the gut.The objective of this study was to determine the effects of ursodeoxycholic acid(UDCA),a postulated gut FXR antagonist with liver protective effects,on the mitigation and prevention of MASH development in mice with hepatic FXR deficiency.Methods For this experiment,six-week old to eight week-old male and female liver-specific FXR knockout(FXRhep-/-)and control(FXRhep flox/flox)mice were fed either a low-fat control diet(CTL)or a MASH‘Fast Food’diet(Western diet with 21%milk fat,1.25%cholesterol and 34%sucrose)both supplemented with or without 0.1%(weight/weight;w/w)UDCA for 16 weeks.Results UDCA feeding tended to reduce alanine aminotransferase levels and decrease liver lipids in the male mice.Supplementation of UDCA showed a trend towards increased UDCA and tauroursodeoxycholic acid(TUDCA)levels in serum,liver and intestine,although the male mice displayed more than twice the amount of these bile acids compared with the female mice.CTL-UDCA feeding resulted in a significant induction of Fxr and Fgf15 mRNA expression in the ileum of the male mice.Conclusion The data strongly suggest that UDCA seems to act as an FXR agonist,especially in the ileum,which contrasts with previous reports that UDCA acts as a gut FXR antagonist.In addition,UDCA seems to be exerting liver protective effects predominantly in the male mice.展开更多
Bile acids(BAs) are amphipathic molecules important for metabolism of cholesterol,absorption of lipids and lipid soluble vitamins,bile flow,and regulation of gut microbiome.There are over 30 different BA species known...Bile acids(BAs) are amphipathic molecules important for metabolism of cholesterol,absorption of lipids and lipid soluble vitamins,bile flow,and regulation of gut microbiome.There are over 30 different BA species known to exist in humans and mice,which are endogenous modulators of at least 6 different membrane or nuclear receptors.This diversity of ligands and receptors play important roles in health and disease;however,the full functions of each individual BA in vivo remain unclear.We generated a mouse model lacking the initiating enzymes,CYP7 A1 and CYP27 A1,in the two main pathways of BA synthesis.Because females are more susceptible to BA related diseases,such as intrahepatic cholestasis of pregnancy,we expanded this model into female mice.The null mice of Cyp7 a1 and Cyp27 a1 were crossbred to create double knockout(DKO) mice.BA concentrations in female DKO mice had reductions in serum(63%),liver(83%),gallbladder(94%),and small intestine(85%),as compared to WT mice.Despite low BA levels,DKO mice had a similar expression pattern to that of WT mice for genes involved in BA regulation,synthesis,conjugation,and transport.Additionally,through treatment with a synthetic FXR agonist,GW4064,female DKO mice responded to FXR activation similarly to WT mice.展开更多
Quaternary ammonium compounds(QACs)are a class of antimicrobial disinfectants whose use in cleaning products increased during the COVID-19 pandemic.Chemically,their low vapor pressure indicates a proclivity to persist...Quaternary ammonium compounds(QACs)are a class of antimicrobial disinfectants whose use in cleaning products increased during the COVID-19 pandemic.Chemically,their low vapor pressure indicates a proclivity to persist on surfaces,and their presence suggests a level of protection against microorganisms.The widespread application of QACs in response to the SARS CoV-2 virus created a need to evaluate their longevity on surfaces,for both efficacy and possible health risks.There are however,no standardized analytical methods for QAC surface sampling and analysis,and no published studies quantifying their concentrations on mass transportation vehicles-a high occupancy,close-contact microenvironment documented to facilitate the spread the SARS CoV-2 virus.Here,we describe a robust liquid chromatography mass spectrometry(LC-MS)method for the analysis of QACs and simultaneous development of a direct surface sampling and extraction protocol.We demonstrate the applicability of the method through the analysis of surface samples collected from in-service public transportation buses.The rapid,sensitive LC-MS method included 8 target QACs quantified on a Q-Exactive HF Hybrid Quadrupole-Orbitrap mass spectrometer using an electrospray ionization source and Dionex UltiMate 3000 UHPLC system for analyte separation.QAC standard mixtures at concentrations between 0.1 ng mL^(-1)and 2000 ng mL^(-1)were analyzed,and chromatographic separation of all analytes was achieved in less than 10 min.All correlation coefficients were reported at r>0.986,and LODs ranged from 0.007 to 2.103 ng mL^(-1)for all compounds,confirming the method's sensitivity.A previously reported surface sampling and extraction protocol was modified to further simplify the procedure and expand the number of target compounds.The new sampling protocol was optimized from 10 commercially available wipes and 4 solvent types by quantifying recovery from the surface.Band-Aid brand small gauze pads saturated with isopropanol had the highest recovery efficiencies,ranging from 61.5 to 102.9%across all analytes.To test the real-world applicability,wipe samples were collected from 4 in-circulation New Jersey Transit buses on 5 separate days over the course of a month to assess the occurrence and longevity of QACs on sanitized mass transportation vehicles.Concentrations of QACs were detected on every wipe sample taken,and at all sampled time points,confirming their persistence on hard surfaces.QACs have the potential to form polymers,and detection of the polymer might serve as a secondary indication of their effectiveness on surfaces.None of the polymers detected however,were unique to QACs from this study.The polymers detected were already present in the wipe and used as an internal standard to demonstrate the efficacy of extraction and analysis of polymeric QACs.展开更多
基金supported by the National Institutes of Health(Grants:DK137451,DK122725,ES007148,ES029258,ES020721,ES005022,GM135258)the Department of Veteran Affairs(BX002741)American Society for Pharmacology and Experimental Therapeutics(ASPET)Summer Intern Program and the Rutgers University Center for Lipid Research.
文摘Background Farnesoid X receptor(FXR)has been identified as a therapeutic target for metabolic dysfunction-associated steatohepatitis(MASH).Hepatic FXR is especially critical in suppressing liver inflammation.FXR agonism and antagonism have both proven to be beneficial in the mitigation of MASH,leading to much controversy in the field,particularly regarding FXR signalling in the gut.The objective of this study was to determine the effects of ursodeoxycholic acid(UDCA),a postulated gut FXR antagonist with liver protective effects,on the mitigation and prevention of MASH development in mice with hepatic FXR deficiency.Methods For this experiment,six-week old to eight week-old male and female liver-specific FXR knockout(FXRhep-/-)and control(FXRhep flox/flox)mice were fed either a low-fat control diet(CTL)or a MASH‘Fast Food’diet(Western diet with 21%milk fat,1.25%cholesterol and 34%sucrose)both supplemented with or without 0.1%(weight/weight;w/w)UDCA for 16 weeks.Results UDCA feeding tended to reduce alanine aminotransferase levels and decrease liver lipids in the male mice.Supplementation of UDCA showed a trend towards increased UDCA and tauroursodeoxycholic acid(TUDCA)levels in serum,liver and intestine,although the male mice displayed more than twice the amount of these bile acids compared with the female mice.CTL-UDCA feeding resulted in a significant induction of Fxr and Fgf15 mRNA expression in the ileum of the male mice.Conclusion The data strongly suggest that UDCA seems to act as an FXR agonist,especially in the ileum,which contrasts with previous reports that UDCA acts as a gut FXR antagonist.In addition,UDCA seems to be exerting liver protective effects predominantly in the male mice.
基金supported by the National Institutes of Health(NIHR01GM104037,NIH-R21ES029258,NIH-T32ES007148,VA-BX002741,NIH-F31DK122725,RCLR graduate student award fund,USA)。
文摘Bile acids(BAs) are amphipathic molecules important for metabolism of cholesterol,absorption of lipids and lipid soluble vitamins,bile flow,and regulation of gut microbiome.There are over 30 different BA species known to exist in humans and mice,which are endogenous modulators of at least 6 different membrane or nuclear receptors.This diversity of ligands and receptors play important roles in health and disease;however,the full functions of each individual BA in vivo remain unclear.We generated a mouse model lacking the initiating enzymes,CYP7 A1 and CYP27 A1,in the two main pathways of BA synthesis.Because females are more susceptible to BA related diseases,such as intrahepatic cholestasis of pregnancy,we expanded this model into female mice.The null mice of Cyp7 a1 and Cyp27 a1 were crossbred to create double knockout(DKO) mice.BA concentrations in female DKO mice had reductions in serum(63%),liver(83%),gallbladder(94%),and small intestine(85%),as compared to WT mice.Despite low BA levels,DKO mice had a similar expression pattern to that of WT mice for genes involved in BA regulation,synthesis,conjugation,and transport.Additionally,through treatment with a synthetic FXR agonist,GW4064,female DKO mice responded to FXR activation similarly to WT mice.
基金the support of the Center for Environmental Exposures and Disease(CEED)NIH-NIEHS Grant nos.P30 ES005022 and T32 ES019854This research was supported in part by Grant no.69A3551847102 from the U.S.Department of Transportation,Office of the Assistant Secretary for Research and Technology(OST-R).
文摘Quaternary ammonium compounds(QACs)are a class of antimicrobial disinfectants whose use in cleaning products increased during the COVID-19 pandemic.Chemically,their low vapor pressure indicates a proclivity to persist on surfaces,and their presence suggests a level of protection against microorganisms.The widespread application of QACs in response to the SARS CoV-2 virus created a need to evaluate their longevity on surfaces,for both efficacy and possible health risks.There are however,no standardized analytical methods for QAC surface sampling and analysis,and no published studies quantifying their concentrations on mass transportation vehicles-a high occupancy,close-contact microenvironment documented to facilitate the spread the SARS CoV-2 virus.Here,we describe a robust liquid chromatography mass spectrometry(LC-MS)method for the analysis of QACs and simultaneous development of a direct surface sampling and extraction protocol.We demonstrate the applicability of the method through the analysis of surface samples collected from in-service public transportation buses.The rapid,sensitive LC-MS method included 8 target QACs quantified on a Q-Exactive HF Hybrid Quadrupole-Orbitrap mass spectrometer using an electrospray ionization source and Dionex UltiMate 3000 UHPLC system for analyte separation.QAC standard mixtures at concentrations between 0.1 ng mL^(-1)and 2000 ng mL^(-1)were analyzed,and chromatographic separation of all analytes was achieved in less than 10 min.All correlation coefficients were reported at r>0.986,and LODs ranged from 0.007 to 2.103 ng mL^(-1)for all compounds,confirming the method's sensitivity.A previously reported surface sampling and extraction protocol was modified to further simplify the procedure and expand the number of target compounds.The new sampling protocol was optimized from 10 commercially available wipes and 4 solvent types by quantifying recovery from the surface.Band-Aid brand small gauze pads saturated with isopropanol had the highest recovery efficiencies,ranging from 61.5 to 102.9%across all analytes.To test the real-world applicability,wipe samples were collected from 4 in-circulation New Jersey Transit buses on 5 separate days over the course of a month to assess the occurrence and longevity of QACs on sanitized mass transportation vehicles.Concentrations of QACs were detected on every wipe sample taken,and at all sampled time points,confirming their persistence on hard surfaces.QACs have the potential to form polymers,and detection of the polymer might serve as a secondary indication of their effectiveness on surfaces.None of the polymers detected however,were unique to QACs from this study.The polymers detected were already present in the wipe and used as an internal standard to demonstrate the efficacy of extraction and analysis of polymeric QACs.
