Hepatocyte nuclear factor 1 alpha(HNF1A),hepatocyte nuclear factor 4 alpha(HNF4A),and forkhead box protein A2(FOXA2)are key transcription factors that regulate a complex gene network in the liver,cre-ating a regulator...Hepatocyte nuclear factor 1 alpha(HNF1A),hepatocyte nuclear factor 4 alpha(HNF4A),and forkhead box protein A2(FOXA2)are key transcription factors that regulate a complex gene network in the liver,cre-ating a regulatory transcriptional loop.The Encode and ChIP-Atlas databases identify the recognition sites of these transcription factors in many glycosyltransferase genes.Our in silico analysis of HNF1A,HNF4A.and FOXA2 binding to the ten candidate glyco-genes studied in this work confirms a significant enrich-ment of these transcription factors specifically in the liver.Our previous studies identified HNF1A as a master regulator of fucosylation,glycan branching,and galactosylation of plasma glycoproteins.Here,we aimed to functionally validate the role of the three transcription factors on downstream glyco-gene transcriptional expression and the possible effect on glycan phenotype.We used the state-of-the-art clus-tered regularly interspaced short palindromic repeats/dead Cas9(CRISPR/dCas9)molecular tool for the downregulation of the HNF1A,HNF4A,and FOXA2 genes in HepG2 cells-a human liver cancer cell line.The results show that the downregulation of all three genes individually and in pairs affects the transcrip-tional activity of many glyco-genes,although downregulation of glyco-genes was not always followed by an unambiguous change in the corresponding glycan structures.The effect is better seen as an overall change in the total HepG2 N-glycome,primarily due to the extension of biantennary glycans.We propose an alternative way to evaluate the N-glycome composition via estimating the overall complexity of the glycome by quantifying the number of monomers in each glycan structure.We also propose a model showing feedback loops with the mutual activation of HNF1A-FOXA2 and HNF4A-FOXA2 affecting glyco-genes and protein glycosylation in HepG2 cells.展开更多
The nuclear receptor hepatocyte nuclear factor 4alpha(HNF4α)plays a critical role in the regulation of metabolic homeostasis,including glucose homeostasis.Sulfotransferases(SULTs)catalyze the transfer of a sulfate gr...The nuclear receptor hepatocyte nuclear factor 4alpha(HNF4α)plays a critical role in the regulation of metabolic homeostasis,including glucose homeostasis.Sulfotransferases(SULTs)catalyze the transfer of a sulfate group from 3-phosphoadenosine 5-phosphosulfate(PAPS)to an acceptor molecule.Sulfonation plays an essential role in regulating the chemical and functional homeostasis of endogenous and exogenous molecules.Among SULTs,the cholesterol sulfotransferase 2B1b(SULT2B1b)preferentially catalyzes the sulfoconjugation of cholesterol and oxysterols to form cholesterol sulfate and oxysterol sulfates.Hepatic gluconeogenesis represents a critical component of energy metabolism.Although there have been reviews on the regulation of glucose homeostasis by HNF4a,the interplay between HNF4a and SULT2B1b in hepatic glucose homeostasis remains scattered.In this review,we intend to provide an overview on how HNF4a functionally cross-talks with SULT2B1b to regulate hepatic glucose homeostasis and whether the HNF4a-SULT2B1b axis represents a novel therapeutic target for the management of metabolic liver disease and metabolic syndrome.展开更多
基金the European Structural and Investment Funded Grant"Cardio Metabolic"(#KK.01.2.1.02.0321)the Croatian National Centre of Research Excellence in Personalized Healthcare Grant(#KK.01.1.1.01.0010)+2 种基金the European Regional Development Fund Grant,project"CRISPR/Cas9-CasMouse"(#KK.01.1.1.04.0085)the European Structural and Investment Funded Project of Centre of Competence in Molecular Diagnostics(#KK.01.2.2.03.0006)the Croatian National Centre of Research Excellence in Personalized Healthcare Grant(#KK.01.1.1.01.0010).
文摘Hepatocyte nuclear factor 1 alpha(HNF1A),hepatocyte nuclear factor 4 alpha(HNF4A),and forkhead box protein A2(FOXA2)are key transcription factors that regulate a complex gene network in the liver,cre-ating a regulatory transcriptional loop.The Encode and ChIP-Atlas databases identify the recognition sites of these transcription factors in many glycosyltransferase genes.Our in silico analysis of HNF1A,HNF4A.and FOXA2 binding to the ten candidate glyco-genes studied in this work confirms a significant enrich-ment of these transcription factors specifically in the liver.Our previous studies identified HNF1A as a master regulator of fucosylation,glycan branching,and galactosylation of plasma glycoproteins.Here,we aimed to functionally validate the role of the three transcription factors on downstream glyco-gene transcriptional expression and the possible effect on glycan phenotype.We used the state-of-the-art clus-tered regularly interspaced short palindromic repeats/dead Cas9(CRISPR/dCas9)molecular tool for the downregulation of the HNF1A,HNF4A,and FOXA2 genes in HepG2 cells-a human liver cancer cell line.The results show that the downregulation of all three genes individually and in pairs affects the transcrip-tional activity of many glyco-genes,although downregulation of glyco-genes was not always followed by an unambiguous change in the corresponding glycan structures.The effect is better seen as an overall change in the total HepG2 N-glycome,primarily due to the extension of biantennary glycans.We propose an alternative way to evaluate the N-glycome composition via estimating the overall complexity of the glycome by quantifying the number of monomers in each glycan structure.We also propose a model showing feedback loops with the mutual activation of HNF1A-FOXA2 and HNF4A-FOXA2 affecting glyco-genes and protein glycosylation in HepG2 cells.
基金supported in part by the USA National Institutes of Health(NIH)grants DK099232,ES023438 and ES030429 to W.Xie.W.Xie was supported in part by the Joseph Koslow Endowed Professorship from the University of Pittsburgh School of Pharmacy.
文摘The nuclear receptor hepatocyte nuclear factor 4alpha(HNF4α)plays a critical role in the regulation of metabolic homeostasis,including glucose homeostasis.Sulfotransferases(SULTs)catalyze the transfer of a sulfate group from 3-phosphoadenosine 5-phosphosulfate(PAPS)to an acceptor molecule.Sulfonation plays an essential role in regulating the chemical and functional homeostasis of endogenous and exogenous molecules.Among SULTs,the cholesterol sulfotransferase 2B1b(SULT2B1b)preferentially catalyzes the sulfoconjugation of cholesterol and oxysterols to form cholesterol sulfate and oxysterol sulfates.Hepatic gluconeogenesis represents a critical component of energy metabolism.Although there have been reviews on the regulation of glucose homeostasis by HNF4a,the interplay between HNF4a and SULT2B1b in hepatic glucose homeostasis remains scattered.In this review,we intend to provide an overview on how HNF4a functionally cross-talks with SULT2B1b to regulate hepatic glucose homeostasis and whether the HNF4a-SULT2B1b axis represents a novel therapeutic target for the management of metabolic liver disease and metabolic syndrome.
