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
Objective:Hepatocyte nuclear factor 4α(HNF4 A)has been demonstrated to be an oncogene in gastric cancer(GC).However,the roles of different HNF4 A isoforms derived from the 2 different promoters(P1 and P2)and the unde...Objective:Hepatocyte nuclear factor 4α(HNF4 A)has been demonstrated to be an oncogene in gastric cancer(GC).However,the roles of different HNF4 A isoforms derived from the 2 different promoters(P1 and P2)and the underlying mechanisms remain obscure.Methods:The expression and prognostic values of P1-and P2-HNF4 A were evaluated in The Cancer Genome Atlas(TCGA)databases and GC tissues.Then,functional assays of P1-and P2-HNF4 A were conducted both in vivo and in vitro.High-throughput RNA-seq was employed to profile downstream pathways in P1-and P2-HNF4 A-overexpressing GC cells.The expression and gene regulation network of the candidate target genes identified by RNA-seq were characterized based on data mining and functional assays.Results:HNF4 A amplification was a key characteristic of GC in TCGA databases,especially for the intestinal type and early stage.Moreover,P1-HNF4 A expression was significantly higher in tumor tissues than in adjacent non-tumor tissues(P<0.05),but no significant differences were found in P2-HNF4 A expression(P>0.05).High P1-HNF4 A expression indicated poor prognoses in GC patients(P<0.01).Furthermore,P1-HNF4 A overexpression significantly promoted SGC7901 and BGC823 cell proliferation,invasion and migration in vitro(P<0.01).Murine xenograft experiments showed that P1-HNF4 A overexpression promoted tumor growth(P<0.05).Mechanistically,RNA-seq showed that the cytokine-cytokine receptor interactions pathway was mostly enriched in P1-HNF4 A-overexpressing GC cells.Finally,chemokine(C-C motif)ligand 15 was identified as a direct target of P1-HNF4 A in GC tissues.Conclusions:P1-HNF4 A was the main oncogene during GC progression.The cytokine-cytokine receptor interaction pathway played a pivotal role and may be a promising therapeutic target.展开更多
Background KCNJ11, ABCC8, PPARG, and HNF4A have been found to be associated with type 2 diabetes in populations with different genetic backgrounds. The aim of this study was to test, in a Chinese Han population from B...Background KCNJ11, ABCC8, PPARG, and HNF4A have been found to be associated with type 2 diabetes in populations with different genetic backgrounds. The aim of this study was to test, in a Chinese Han population from Beijing, whether the genetic variants in these four genes were associated with genetic predisposition to type 2 diabetes. Methods We studied the association of four representative SNPs in KCNJ11, ABCC8, PPARG, and HNF4A by genotyping them using ABI SNaPshot Multiplex System in 400 unrelated type 2 diabetic patients and 400 unrelated normoglycaemic subjects. Results rs5219（E23K） in KCNJ11 was associated with genetic susceptibility to type 2 diabetes （OR=1.400 with 95% CI 1.117 1.755, P=0.004 under an additive model, 0R=1.652 with 95% CI 1.086 2.513, P=0.019 under a recessive model, and OR=1.521 with 95% Cl 1.089 2.123, P=0.014 under a dominant model） after adjusting for sex and body mass index （BMI）. We did not find evidence of association for ABCC8 rs1799854, PPARG rs1801282 （Pro12Ala） and HNF4A rs2144908. Genotype-phenotype correlation analysis revealed that rs1799854 in ABCC8 was associated with 2-hour postprandial insulin secretion （P=0.005） after adjusting for sex, age and BMI. Although no interactions between the four variants on the risk of type 2 diabetes were detected, the multiplicative interaction between PPARG Pro12Ala and HNF4A rs2144908 was found to be associated with 2-hour postprandial insulin （P=-0.004 under an additive model for rs2144908; and P=0.001 under a dominant model for rs2144908） after adjusting for age, sex and BMI, assuming a dominant model for PPARG Pro12Ala. Conclusions Our study replicated the association of rs5219 in KCNJ11 with type 2 diabetes in Chinese Han population in Beijing. And we also observed that ABCC8 as well as the interaction between PPARG and HNF4A may contribute to post-challenge insulin secretion.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 by the National Natural Science Foundation of China(Grant No.81873554)Shaanxi Foundation for Innovation Team of Science and Technology(Grant No.2018TD-003)。
文摘Objective:Hepatocyte nuclear factor 4α(HNF4 A)has been demonstrated to be an oncogene in gastric cancer(GC).However,the roles of different HNF4 A isoforms derived from the 2 different promoters(P1 and P2)and the underlying mechanisms remain obscure.Methods:The expression and prognostic values of P1-and P2-HNF4 A were evaluated in The Cancer Genome Atlas(TCGA)databases and GC tissues.Then,functional assays of P1-and P2-HNF4 A were conducted both in vivo and in vitro.High-throughput RNA-seq was employed to profile downstream pathways in P1-and P2-HNF4 A-overexpressing GC cells.The expression and gene regulation network of the candidate target genes identified by RNA-seq were characterized based on data mining and functional assays.Results:HNF4 A amplification was a key characteristic of GC in TCGA databases,especially for the intestinal type and early stage.Moreover,P1-HNF4 A expression was significantly higher in tumor tissues than in adjacent non-tumor tissues(P<0.05),but no significant differences were found in P2-HNF4 A expression(P>0.05).High P1-HNF4 A expression indicated poor prognoses in GC patients(P<0.01).Furthermore,P1-HNF4 A overexpression significantly promoted SGC7901 and BGC823 cell proliferation,invasion and migration in vitro(P<0.01).Murine xenograft experiments showed that P1-HNF4 A overexpression promoted tumor growth(P<0.05).Mechanistically,RNA-seq showed that the cytokine-cytokine receptor interactions pathway was mostly enriched in P1-HNF4 A-overexpressing GC cells.Finally,chemokine(C-C motif)ligand 15 was identified as a direct target of P1-HNF4 A in GC tissues.Conclusions:P1-HNF4 A was the main oncogene during GC progression.The cytokine-cytokine receptor interaction pathway played a pivotal role and may be a promising therapeutic target.
文摘Background KCNJ11, ABCC8, PPARG, and HNF4A have been found to be associated with type 2 diabetes in populations with different genetic backgrounds. The aim of this study was to test, in a Chinese Han population from Beijing, whether the genetic variants in these four genes were associated with genetic predisposition to type 2 diabetes. Methods We studied the association of four representative SNPs in KCNJ11, ABCC8, PPARG, and HNF4A by genotyping them using ABI SNaPshot Multiplex System in 400 unrelated type 2 diabetic patients and 400 unrelated normoglycaemic subjects. Results rs5219（E23K） in KCNJ11 was associated with genetic susceptibility to type 2 diabetes （OR=1.400 with 95% CI 1.117 1.755, P=0.004 under an additive model, 0R=1.652 with 95% CI 1.086 2.513, P=0.019 under a recessive model, and OR=1.521 with 95% Cl 1.089 2.123, P=0.014 under a dominant model） after adjusting for sex and body mass index （BMI）. We did not find evidence of association for ABCC8 rs1799854, PPARG rs1801282 （Pro12Ala） and HNF4A rs2144908. Genotype-phenotype correlation analysis revealed that rs1799854 in ABCC8 was associated with 2-hour postprandial insulin secretion （P=0.005） after adjusting for sex, age and BMI. Although no interactions between the four variants on the risk of type 2 diabetes were detected, the multiplicative interaction between PPARG Pro12Ala and HNF4A rs2144908 was found to be associated with 2-hour postprandial insulin （P=-0.004 under an additive model for rs2144908; and P=0.001 under a dominant model for rs2144908） after adjusting for age, sex and BMI, assuming a dominant model for PPARG Pro12Ala. Conclusions Our study replicated the association of rs5219 in KCNJ11 with type 2 diabetes in Chinese Han population in Beijing. And we also observed that ABCC8 as well as the interaction between PPARG and HNF4A may contribute to post-challenge insulin secretion.
