A rapid and sensitive liquid chromatography–tandem mass spectrometry(LC–MS/MS) method was developed and validated for the simultaneous determination of H002 and its phosphorylated metabolite, H002-P and hydroxylated...A rapid and sensitive liquid chromatography–tandem mass spectrometry(LC–MS/MS) method was developed and validated for the simultaneous determination of H002 and its phosphorylated metabolite, H002-P and hydroxylated metabolite H002-M, in rat blood. H001, an analogue of H002, was used as the internal standard.Blood samples were prepared by simple protein precipitation. The analytes and internal standard were separated on a Zorbax SB-C18 column with a gradient mobile phase consisting of methanol and water containing 0.1% formic acid at a flow rate of 0.2 mL /min with an operating temperature of 20 1C. The detection was performed on a triple quadrupole tandem mass spectrometer with positive electrospray ionization in multiple-reaction monitoring mode.Linear detection responses were obtained from 0.2–100 ng/mL for H002 and H002-M, while 0.5–100 ng/mL for H002-P. The intra- and inter-day precision(RSD%) was within 11.76%, with the accuracy(RE%) ranging from –9.84% to 9.12%. The analytes were shown to be stable during sample storage, preparation and analytic procedures.The method was applied to determine the pharmacokinetics of H002 in rats, and a preliminary study showed that the pharmacokinetics of H002 correlated with its biological effect on peripheral blood lymphocytes.展开更多
The liver is the central organ involved in lipid metabolism and the gastrointestinal(GI)tract is responsible for nutrient absorption and partitioning.Obesity,dyslipidemia and metabolic disorders are of increasing publ...The liver is the central organ involved in lipid metabolism and the gastrointestinal(GI)tract is responsible for nutrient absorption and partitioning.Obesity,dyslipidemia and metabolic disorders are of increasing public health concern worldwide,and novel therapeutics that target both the liver and the GI tract(gut-liver axis)are much needed.In addition to aiding fat digestion,bile acids act as important signaling molecules that regulate lipid,glucose and energy metabolism via activating nuclear receptor,G protein-coupled receptors(GPCRs),Takeda G protein receptor 5(TGR5)and sphingosine-1-phosphate receptor 2(S1PR2).Sphingosine-1-phosphate(S1P)is synthesized by two sphingosine kinase isoforms and is a potent signaling molecule that plays a critical role in various diseases such as fatty liver,in-flammatory bowel disease(IBD)and colorectal cancer.In this review,we will focus on recent findings related to the role of S1P-mediated signaling pathways in the gut-liver axis.展开更多
Over 20%of mortality during acute liver failure is associated with the development of hepatic encephalopathy(HE).Thus,HE is a complication of acute liver failure with a broad spectrum of neuropsychiatric abnormalities...Over 20%of mortality during acute liver failure is associated with the development of hepatic encephalopathy(HE).Thus,HE is a complication of acute liver failure with a broad spectrum of neuropsychiatric abnormalities ranging from subclinical alterations to coma.HE is caused by the diversion of portal blood into systemic circulation through portosystemic collateral vessels.Thus,the brain is exposed to intestinal-derived toxic substances.Moreover,the strategies to prevent advancement and improve the prognosis of such a liver-brain disease rely on intestinal microbial modulation.This is supported by the findings that antibiotics such as rifaximin and laxative lactulose can alleviate hepatic cirrhosis and/or prevent HE.Together,the significance of the gut-liver-brain axis in human health warrants attention.This review paper focuses on the roles of bacteria metabolites,mainly ammonia and bile acids(BAs)as well as BA receptors in HE.The literature search conducted for this review included searches for phrases such as BA receptors,BAs,ammonia,farnesoid X receptor(FXR),G protein-coupled bile acid receptor 1(GPBAR1 or TGR5),sphingosine-1-phosphate receptor 2(S1PR2),and cirrhosis in conjunction with the phrase hepatic encephalopathy and portosystemic encephalopathy.PubMed,as well as Google Scholar,was the search engines used to find relevant publications.展开更多
Many receptors can be activated by bile acids(BAs)and their derivatives.These include nuclear receptors farnesoid X receptor(FXR),pregnane X receptor(PXR),and vitamin D receptor(VDR),as well as membrane receptors Take...Many receptors can be activated by bile acids(BAs)and their derivatives.These include nuclear receptors farnesoid X receptor(FXR),pregnane X receptor(PXR),and vitamin D receptor(VDR),as well as membrane receptors Takeda G protein receptor 5(TGR5),sphingosine-1-phosphate receptor 2(S1PR2),and cholinergic receptor muscarinic 2(CHRM2).All of them are implicated in the development of metabolic and immunological diseases in response to endobiotic and xenobiotic exposure.Because epigenetic regulation is critical for organisms to adapt to constant environmental changes,this review article summarizes epigenetic regulation as well as post-transcriptional modification of bile acid re-ceptors.In addition,the focus of this review is on the liver and digestive tract although these receptors may have effects on other organs.Those regulatory mechanisms are implicated in the disease process and critically important in uncovering innovative strategy for prevention and treatment of metabolic and immunological diseases.展开更多
基金supported by the National Science and Technology Major Project of China(Nos.2012ZX09301002-001-007 and2012ZX09301002-006)National Natural Science Foundation of China(NSFC,Nos.81202545,81302847 and 81473096)
文摘A rapid and sensitive liquid chromatography–tandem mass spectrometry(LC–MS/MS) method was developed and validated for the simultaneous determination of H002 and its phosphorylated metabolite, H002-P and hydroxylated metabolite H002-M, in rat blood. H001, an analogue of H002, was used as the internal standard.Blood samples were prepared by simple protein precipitation. The analytes and internal standard were separated on a Zorbax SB-C18 column with a gradient mobile phase consisting of methanol and water containing 0.1% formic acid at a flow rate of 0.2 mL /min with an operating temperature of 20 1C. The detection was performed on a triple quadrupole tandem mass spectrometer with positive electrospray ionization in multiple-reaction monitoring mode.Linear detection responses were obtained from 0.2–100 ng/mL for H002 and H002-M, while 0.5–100 ng/mL for H002-P. The intra- and inter-day precision(RSD%) was within 11.76%, with the accuracy(RE%) ranging from –9.84% to 9.12%. The analytes were shown to be stable during sample storage, preparation and analytic procedures.The method was applied to determine the pharmacokinetics of H002 in rats, and a preliminary study showed that the pharmacokinetics of H002 correlated with its biological effect on peripheral blood lymphocytes.
基金This work was supported by the USA National Institutes of Health(NIH)grants R01 DK104893 and R01DK-057543VA Merit Award I01BX004033 and 1I01BX001390Research Career Scientist Award(IK6BX004477)from the Department of Veterans Affairs.
文摘The liver is the central organ involved in lipid metabolism and the gastrointestinal(GI)tract is responsible for nutrient absorption and partitioning.Obesity,dyslipidemia and metabolic disorders are of increasing public health concern worldwide,and novel therapeutics that target both the liver and the GI tract(gut-liver axis)are much needed.In addition to aiding fat digestion,bile acids act as important signaling molecules that regulate lipid,glucose and energy metabolism via activating nuclear receptor,G protein-coupled receptors(GPCRs),Takeda G protein receptor 5(TGR5)and sphingosine-1-phosphate receptor 2(S1PR2).Sphingosine-1-phosphate(S1P)is synthesized by two sphingosine kinase isoforms and is a potent signaling molecule that plays a critical role in various diseases such as fatty liver,in-flammatory bowel disease(IBD)and colorectal cancer.In this review,we will focus on recent findings related to the role of S1P-mediated signaling pathways in the gut-liver axis.
基金the USA National Institutes of Health(NIH)R01CA222490.
文摘Over 20%of mortality during acute liver failure is associated with the development of hepatic encephalopathy(HE).Thus,HE is a complication of acute liver failure with a broad spectrum of neuropsychiatric abnormalities ranging from subclinical alterations to coma.HE is caused by the diversion of portal blood into systemic circulation through portosystemic collateral vessels.Thus,the brain is exposed to intestinal-derived toxic substances.Moreover,the strategies to prevent advancement and improve the prognosis of such a liver-brain disease rely on intestinal microbial modulation.This is supported by the findings that antibiotics such as rifaximin and laxative lactulose can alleviate hepatic cirrhosis and/or prevent HE.Together,the significance of the gut-liver-brain axis in human health warrants attention.This review paper focuses on the roles of bacteria metabolites,mainly ammonia and bile acids(BAs)as well as BA receptors in HE.The literature search conducted for this review included searches for phrases such as BA receptors,BAs,ammonia,farnesoid X receptor(FXR),G protein-coupled bile acid receptor 1(GPBAR1 or TGR5),sphingosine-1-phosphate receptor 2(S1PR2),and cirrhosis in conjunction with the phrase hepatic encephalopathy and portosystemic encephalopathy.PubMed,as well as Google Scholar,was the search engines used to find relevant publications.
基金This study was supported by grants funded by the USA National Institutes of Health(NIH)U01CA179582 and R01 CA222490.
文摘Many receptors can be activated by bile acids(BAs)and their derivatives.These include nuclear receptors farnesoid X receptor(FXR),pregnane X receptor(PXR),and vitamin D receptor(VDR),as well as membrane receptors Takeda G protein receptor 5(TGR5),sphingosine-1-phosphate receptor 2(S1PR2),and cholinergic receptor muscarinic 2(CHRM2).All of them are implicated in the development of metabolic and immunological diseases in response to endobiotic and xenobiotic exposure.Because epigenetic regulation is critical for organisms to adapt to constant environmental changes,this review article summarizes epigenetic regulation as well as post-transcriptional modification of bile acid re-ceptors.In addition,the focus of this review is on the liver and digestive tract although these receptors may have effects on other organs.Those regulatory mechanisms are implicated in the disease process and critically important in uncovering innovative strategy for prevention and treatment of metabolic and immunological diseases.