Aim In diabetic patients, metformin appears to provide cardiovascular protection that cannot be attribu- ted only to its antihyperglycemic effects. Metformin is also known as the AMP-activated protein kinase (AMPK) ...Aim In diabetic patients, metformin appears to provide cardiovascular protection that cannot be attribu- ted only to its antihyperglycemic effects. Metformin is also known as the AMP-activated protein kinase (AMPK) ac- tivator. Our previous study suggested that metformin inhibits transforming growth factor-β1 (TGF-β1) production in a mouse heart failure model of pressure overload. TGF-β1 is a key factor in cardiac fibrosis and is usually induced by Angiotensin Ⅱ (Ang Ⅱ ) in the pressure overload mouse models. This study investigated the effect of metformin on cardiac fibrosis and TGF-β production induced by AngII and the underlying mechanisms. Methods C57/BL6 wild-type and AMPKα2 knockout mice were used. AngII (3 mg · kg-1 · d-1) was infused subcutaneously into mice for 7 days. Adult mouse cardiac fibroblasts were isolated and treated with AngII ( 1 μmol · L-1) and/or met- formin (1 mmol · L-l). Results In C57/BL6 mice, metformin inhibits AngII-induced cardiac fibrosis. In cardi-ac fibroblasts, metformin inhibits TGF-β1 expression and production induced by AngII. AMPK inhibitor, com- pound C, reversed the effects of metformin. In vivo, AMPKα2 deficiency further increases AngII-induced TGF-β1 production. In cardiac fibroblasts, metformin inhibited AngII induced hepatocyte nuclear factor4 (HNF4ot protein level increase and HNF4α binding with TGF-β1 promoter using chromatin immunoprecipitation assay. In vivo, AMPKα2 deficiency further increased AngII-induced HNF4α protein level. Using HNF4α adenovirus, overexpress- ing HNF4α led to a 1.5-fold increase in TGF-β1 mRNA expression. HNF4a siRNA blocked AngII induced TGF- β1 production. Luciferase reporter with deleted HNF4a binding sites showed decreased TGFbl transcriptional activ- ity induced by AngII. In AMPK or2-/- heart, the inhibition of metformin on HNF4a protein was attenuated. Con- clusion Metformin inhibits AngII induced cardiac fibrosis and TGF-β1 production through AMPK activation. The underlying mechanism is that AMPK activation inhibits AngII induced HNF4α and then decreases TGF-β1 expres- sion.展开更多
Hepatocyte nuclear factor 4-alpha(HNF4-α)is a nuclear receptor regulating metabolism,cell junctions,differentiation and proliferation in liver and intestinal epithelial cells.Mutations within the HNF4A gene are assoc...Hepatocyte nuclear factor 4-alpha(HNF4-α)is a nuclear receptor regulating metabolism,cell junctions,differentiation and proliferation in liver and intestinal epithelial cells.Mutations within the HNF4A gene are associated with human diseases such as maturityonset diabetes of the young.Recently,HNF4A has also been described as a susceptibility gene for ulcerative colitis in genome-wide association studies.In addition,specific HNF4A genetic variants have been identified in pediatric cohorts of Crohn’s disease.Results obtained from knockout mice supported that HNF4-αcan protect the intestinal mucosae against inflammation.However,the exact molecular links behind HNF4-αand inflammatory bowel diseases remains elusive.In this review,we will summarize the current knowledge about the role of HNF4-αand its isoforms in inflammation.Specific nature of HNF4-αP1 and P2 classes of isoforms will be summarized.HNF4-αrole as a hepatocyte mediator for cytokines relays during liver inflammation will be integrated based on documented examples of the literature.Conclusions that can be made from these earlier liver studies will serve as a basis to extrapolate correlations and divergences applicable to intestinal inflammation.Finally,potential functional roles for HNF4-αisoforms in protecting the intestinal mucosae from chronic and pathological inflammation will be presented.展开更多
Hepatocyte nuclear factor 4-alpha(HNF4α)is a highly conserved member of nuclear receptor superfamily of ligand-dependent transcription factors that is expressed in liver and gastrointestinal organs(pancreas,stomach,a...Hepatocyte nuclear factor 4-alpha(HNF4α)is a highly conserved member of nuclear receptor superfamily of ligand-dependent transcription factors that is expressed in liver and gastrointestinal organs(pancreas,stomach,and intestine).In liver,HNF4αis best known for its role as a master regulator of liver-specific gene expression and essential for adult and fetal liver function.Dysregulation of HNF4αexpression has been associated with many human diseases such as ulcerative colitis,colon cancer,maturity-onset diabetes of the young,liver cirrhosis,and hepatocellular carcinoma.However,the precise role of HNF4αin the etiology of these human pathogenesis is not well understood.Limited information is known about the role of HNF4αisoforms in liver and gastrointestinal disease progression.There is,therefore,a critical need to know how disruption of the expression of these isoforms may impact on disease progression and phenotypes.In this review,we will update our current understanding on the role of HNF4αin human liver and gastrointestinal diseases.We further provide additional information on possible use of HNF4αas a target for potential therapeutic approaches.展开更多
AIM: To investigate the effect of hepatocyte nuclear factor 4α(HNF4α) on the differentiation and transformation of hepatic stellate cells(HSCs).METHODS: By constructing the recombinant adenovirus vector expressing H...AIM: To investigate the effect of hepatocyte nuclear factor 4α(HNF4α) on the differentiation and transformation of hepatic stellate cells(HSCs).METHODS: By constructing the recombinant adenovirus vector expressing HNF4α and HNF4αshRNA vector, and manipulating HNF4α expression in HSC-T6 cells, we explored the influence of HNF4α and its induction capacity in the differentiation of rat HSCs into hepatocytes.RESULTS: With increased expression of HNF4αmediated by AdHNF4α, the relative expression of Nanog was downregulated in HSC-T6 cells(98.33 ±12.33 vs 41.33 ± 5.67, P < 0.001). Consequently, the expression of G-P-6 and PEPCK was upregulated(G-P-6:14.34 ± 3.33 vs 42.53 ± 5.87, P < 0.01; PEPCK: 10.10± 4.67 vs 56.56 ± 5.25, P < 0.001), the expression of AFP and ALB was positive, and the expression of Nanog, Type Ⅰ collagen, α-SMA, and TIMP-1 was significantly decreased. HNF4α also downregulated vimentin expression and enhanced E-cadherin expression. The ultrastructure of HNF4α-induced cells had more mitochondria and ribosomes compared with the parental cells. After silencing HNF4α expression,EPCK, E-cadherin, AFP, and ALB were downregulated and α-SMA and vimentin were upregulated.CONCLUSION: HNF4α can induce a tendency of differentiation of HSCs into hepatocyte-like cells. These findings may provide an effective way for the treatmentof liver diseases.展开更多
BACKGROUND Gastric cancer is the third deadliest cancer in the world and ranks second in incidence and mortality of cancers in China.Despite advances in prevention,diagnosis,and therapy,the absolute number of cases is...BACKGROUND Gastric cancer is the third deadliest cancer in the world and ranks second in incidence and mortality of cancers in China.Despite advances in prevention,diagnosis,and therapy,the absolute number of cases is increasing every year due to aging and the growth of high-risk populations,and gastric cancer is still a leading cause of cancer-related death.Gastric cancer is a consequence of the complex interaction of microbial agents,with environmental and host factors,resulting in the dysregulation of multiple oncogenic and tumor-suppressing signaling pathways.Global efforts have been made to investigate in detail the genomic and epigenomic heterogeneity of this disease,resulting in the identification of new specific and sensitive predictive and prognostic biomarkers.Trastuzumab,a monoclonal antibody against the HER2 receptor,is approved in the first-line treatment of patients with HER2+tumors,which accounts for 13%-23%of the gastric cancer population.Ramucirumab,a monoclonal antibody against VEGFR2,is currently recommended in patients progressing after first-line treatment.Several clinical trials have also tested novel agents for advanced gastric cancer but mostly with dis-appointing results,such as anti-EGFR and anti-MET monoclonal antibodies.Therefore,it is still of great significance to screen specific molecular targets for gastric cancer and drugs directed against the molecular targets.AIM To investigate the effect and mechanism of berberine against tumor growth in gastric cancer xenograft models and to explore the role of hepatocyte nuclear factor 4α(HNF4α)-WNT5a/β-catenin pathways played in the antitumor effects of berberine.METHODS MGC803 and SGC7901 subcutaneous xenograft models were established.The control group was intragastrically administrated with normal saline,and the berberine group was administrated intragastrically with 100 mg/kg/d berberine.The body weight of nude mice during the experiment was measured to assess whether berberine has any adverse reaction.The volume of subcutaneous tumors during this experiment was recorded to evaluate the inhibitory effect of berberine on the growth of MGC803 and SGC7901 subcutaneous transplantation tumors.Polymerase chain reaction assays were conducted to evaluate the alteration of transcriptional expression of HNF4α,WNT5a andβ-catenin in tumor tissues and liver tissues from the MGC803 and SGC7901 xenograft models.Western blotting and IHC were performed to assess the protein expression of HNF4α,WNT5a andβ-catenin in tumor tissues and liver tissues from the MGC803 and SGC7901 xenograft models.RESULTS In the both MGC803 and SGC7901 xenograft tumor models,berberine significantly reduced tumor volume and weight and thus retarded the growth rate of tumors.In the SGC7901 and MGC803 subcutaneously transplanted tumor models,berberine down-regulated the expression of HNF4α,WNT5a andβ-catenin in tumor tissues from both transcription and protein levels.Besides,berberine also suppressed the protein expression of HNF4α,WNT5a andβ-catenin in liver tissues.CONCLUSION Berberine retarded the growth of MGC803 and SGC7901 xenograft model tumors,and the mechanism behind these anti-growth effects might be the downregulation of the expression of HNF4α-WNT5a/β-catenin signaling pathways both in tumor tissues and liver tissues of the xenograft models.展开更多
AIM To uncover the role of hepatocyte nuclear factor 4 alpha(HNF4α) in regulating hepatic expression of micro RNAs.METHODS Microarray and real-time PCR were used to determine hepatic expression of micro RNAs in young...AIM To uncover the role of hepatocyte nuclear factor 4 alpha(HNF4α) in regulating hepatic expression of micro RNAs.METHODS Microarray and real-time PCR were used to determine hepatic expression of micro RNAs in young-adult mice lacking Hnf4α expression in liver(Hnf4α-Liv KO). Integrative genomics viewer software was used to analyze the public chromatin immunoprecipitation-sequencing datasets for DNA-binding of HNF4α, RNA polymerase-Ⅱ, and histone modifications to loci of micro RNAs in mouse liver and human hepatoma cells. Dual-luciferase reporter assay was conducted to determine effects of HNF4α on the promoters of mouse and human micro RNAs as well as effects of micro RNAs on the untranslated regions(3'UTR) of two genes in human hepatoma cells. RESULTS Microarray data indicated that most micro RNAs remained unaltered by Hnf4α deficiency in Hnf4α-Liv KO mice. However, certain liver-predominant micro RNAs were down-regulated similarly in young-adult male and female Hnf4α-Liv KO mice. The down-regulation of mi R-101, mi R-192, mi R-193 a, mi R-194, mi R-215, mi R-802, and mi R-122 as well as induction of mi R-34 and mi R-29 in male Hnf4α-Liv KO mice were confirmed by real-timePCR. Analysis of public chromatin immunoprecipitationsequencing data indicates that HNF4α directly binds to the promoters of mi R-101, mi R-122, mi R-194-2/mi R-192 and mi R-193, which is associated with histone marks of active transcription. Luciferase reporter assay showed that HNF4α markedly activated the promoters of mouse and human mi R-101b/mi R-101-2 and the mi R-194/mi R-192 cluster. Additionally, mi R-192 and mi R-194 significantly decreased activities of luciferase reporters for the 3'UTR of histone H3F3 and chromodomain helicase DNA binding protein 1(CHD1), respectively, suggesting that mi R-192 and mi R-194 might be important in chromosome remodeling through directly targeting H3F3 and CHD1.CONCLUSION HNF4α is essential for hepatic basal expression of a group of liver-enriched micro RNAs, including mi R-101, mi R-192, mi R-193 a, mi R-194 and mi R-802, through which HNF4α may play a major role in the post-transcriptional regulation of gene expression and maintenance of the epigenome in liver.展开更多
BACKGROUND: Hepatocyte nuclear factor 4 alpha (HNF4α) plays an important role in regulating cytokine-induced inflammatory responses. This study aimed to investigate the role of HNF4α in the development of fulminant ...BACKGROUND: Hepatocyte nuclear factor 4 alpha (HNF4α) plays an important role in regulating cytokine-induced inflammatory responses. This study aimed to investigate the role of HNF4α in the development of fulminant hepatic failure (FHF) induced by lipopolysaccharide/D-galactosamine (LPS/D-GalN). METHODS: The FHF model was induced by simultaneous intraperitoneal injection of LPS/D-GalN in mice. Three days prior to LPS/D-GalN administration, HNF4α short-hairpin interfering RNA expression plasmid or physiological saline was injected via the tail vein with a hydrodynamics-based procedure. The degree of hepatic damage and cumulative survival rate were subsequently assessed. RESULTS: The expression of HNF4α was increased in the early stage after LPS/D-GalN administration. Inhibiting the expression of HNF4α reduced serum levels of alanine aminotransferase and aspartate aminotransferase, alleviated histological injury, and improved the survival of mice with FHF. In addition, both serum and hepatic tumor necrosis factor alpha expression were suppressed when HNF4α expression was inhibited in mice with FHF. CONCLUSION: Inhibiting HNF4α expression protects mice from FHF induced by LPS/D-GalN, but the exact mechanism behind this needs further investigation.展开更多
BACKGROUND Gastric cancer(GC)is the second most common cause of cancer-related deaths worldwide.Hepatocyte nuclear factor 4 alpha(HNF4α)that belongs to the nuclear hormone receptor superfamily,is overexpressed in GC ...BACKGROUND Gastric cancer(GC)is the second most common cause of cancer-related deaths worldwide.Hepatocyte nuclear factor 4 alpha(HNF4α)that belongs to the nuclear hormone receptor superfamily,is overexpressed in GC tissues,and might be involved in the development of GC by regulating its downstream winglessrelated integration site(WNT)/β-catenin signaling.AIM To clarify the expression of HNF4α/WNT5a/β-catenin signaling proteins in clinical GC tissues.METHODS We immunohistochemically stained pathological blocks of GC and matched paracancerous tissues.The intensity of HNF4α,WNT5a andβ-catenin staining in the tumor cells was determined according to cell rates and staining intensity.The correlations between GC and HNF4α,WNT5a,andβ-catenin expression using chisquare and paired chi-square tests.Relationships between double-positive HNF4αand WNT5a expression and types of gastric tumor tissues were assessed using regression analysis.Correlations between HNF4αand WNT5a expression at the RNA level in GC tissues found in the TCGA database were analyzed using Pearson correlation coefficients.RESULTS We found more abundant HNF4αand WNT5a proteins in GC,especially in mucinous adenocarcinoma and mixed GC than in adjacent tissues(P<0.001).Low and high levels of cytoplasmicβ-catenin respectively expressed in GC and adjacent tissues(P<0.001)were not significantly associated with pathological parameters.CONCLUSION The expressions of HNF4αand WNT5a could serve as early diagnostic biomarkers for GC.展开更多
BACKGROUND Intravenous steroid pulse therapy is the treatment of choice for acute exacerbation of multiple sclerosis(MS).Although steroid administration is generally welltolerated,cases of cardiac arrhythmia have been...BACKGROUND Intravenous steroid pulse therapy is the treatment of choice for acute exacerbation of multiple sclerosis(MS).Although steroid administration is generally welltolerated,cases of cardiac arrhythmia have been reported.Herein,we describe a young woman who developed marked sinus bradycardia and T-wave abnormalities after corticosteroid administration.We also present plausible explanations for the abnormalities observed in this patient.CASE SUMMARY An 18-year-old woman experienced vertiginous dizziness and binocular diplopia 1 wk prior to admission.Neurological examination revealed left internuclear ophthalmoplegia with left peripheral-type facial palsy.The initial laboratory results were consistent with those of type 2 diabetes.Brain magnetic resonance imaging revealed multifocal,non-enhancing,symptomatic lesions and multiple enhancing lesions.She was diagnosed with MS and maturity-onset diabetes of the young.Intravenous methylprednisolone was administered.On day 5 after methylprednisolone infusion,marked bradycardia with T-wave abnormalities were observed.Genetic evaluation to elucidate the underlying conditions revealed a hepatocyte nuclear factor 4-alpha(HNF4A)gene mutation.Steroid treatment was discontinued under suspicion of corticosteroid-induced bradycardia.Her electrocardiogram changes returned to normal without complications two days after steroid discontinuation.CONCLUSION Corticosteroid-induced bradycardia may have a significant clinical impact,especially in patients with comorbidities,such as HNF4A mutations.展开更多
Limited treatment options are available for hepatocellular carcinoma(HCC),especially in the advanced stage,which is associated with a poor prognosis.Many studies have demonstrated that hepatocyte nuclear factor 4α(HN...Limited treatment options are available for hepatocellular carcinoma(HCC),especially in the advanced stage,which is associated with a poor prognosis.Many studies have demonstrated that hepatocyte nuclear factor 4α(HNF 4α)plays an important role in hepatic differentiation and the carcinogenesis of HCC.HNF 4αcritically regulates hepatic differentiation by controlling a large number of genes involved in hepatic functions including metabolism,xenobiotic detoxification,bile acid synthesis,and serum protein production.It has also been confirmed to play an important role in the inflammatory environment in HCC.Thus,HNF 4αis considered to be a promising target for the treatment of HCC.Some studies have demonstrated that regulating HNF 4αexpression in HCC had beneficial effects in in vivo and in vitro experiments.We herein review the role of HNF 4αin regulating hepatic metabolism and the inflammatory response,aiming to provide some ideas on induced hepatic differentiation therapy and regulating the inflammatory microenvironment for the treatment of advanced HCC.展开更多
AIM To determine the effects of ω-3 fatty acids(ω-3FA) on the toll-like receptor 4(TLR4)/nuclear factor κB p56(NF-κBp56) signal pathway in the lungs of rats with severe acute pancreatitis(SAP).METHODS A total of 5...AIM To determine the effects of ω-3 fatty acids(ω-3FA) on the toll-like receptor 4(TLR4)/nuclear factor κB p56(NF-κBp56) signal pathway in the lungs of rats with severe acute pancreatitis(SAP).METHODS A total of 56 Sprague-Dawley rats were randomly divided into 4 groups: control group, SAP-saline group, SAP-soybean oil group and SAP-ω-3FA group. SAP was induced by the retrograde infusion of sodium taurocholate into the pancreatic duct. The expression of TLR4 and NF-κBp56 in the lungs was evaluated by immunohistochemistry and Western blot analysis. The levels of inflammatory cytokines interleukin-6 and tumor necrosis factor-alpha in the lungs were measured by enzyme-linked immunosorbent assay. RESULTS The expression of TLR4 and NF-κBp56 in lungs and of inflammatory cytokines in serum significantly increased in the SAP group compared with the control group(P < 0.05), but was significantly decreased in the ω-3FA group compared with the soybean oil group at 12 and 24 h(P < 0.05).CONCLUSION During the initial stage of SAP, ω-3FA can efficiently lower the inflammatory response and reduce lung injury by triggering the TLR4/NF-κBp56 signal pathway.展开更多
Objective To analyze the association of variants of hepatocyte nuclear factor-1α (HNF-1α) gene with type 2 diabetes in Chinese population. Methods In 152 unrelated type 2 diabetes patients and 93 unrelated control...Objective To analyze the association of variants of hepatocyte nuclear factor-1α (HNF-1α) gene with type 2 diabetes in Chinese population. Methods In 152 unrelated type 2 diabetes patients and 93 unrelated controls, eleven single nucleotide polymorphisms (SNPs) were identified and genotyped. Statistical analyses were performed to investigate whether these SNPs were associated with diabetes status in our samples. Results In the individual SNP study, no SNP differed significantly in frequency between type 2 diabetes patients and controls. In the haplotype analysis, two haplotype blocks were identified. In haplotype block 1, no evidence was found between common HNF-1α haplotypes and type 2 diabetes. However, in haplotype block 2, a common haplotype GCGC formed by four tagging SNPs (tSNPs) was found to be associated with decreased risk of type 2 diabetes (odds ratio [OR] 0.6011, 95% confidence interval [CI] 0.4138-0.8732, P=0.0073, empirical P=0.0511, permutation test). A similar trend was also observed in the diplotype analysis, indicating that the increasing copy number of the haplotype GCGC was associated with the decreased frequency of diabetes (P=0.0193). Conclusion The results of this study provide evidence that the haplotype of HNF-1α decreases the risk of type 2 diabetes in Chinese individuals.展开更多
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
AIM: To observe the effect of berberine on insulin secretion in rat pancreatic islets and to explore its possible molecular mechanism. METHODS: Primary rat islets were isolated from male Sprague-Dawley rats by collage...AIM: To observe the effect of berberine on insulin secretion in rat pancreatic islets and to explore its possible molecular mechanism. METHODS: Primary rat islets were isolated from male Sprague-Dawley rats by collagenase digestion and treated with different concentrations (1,3,10 and 30 μmol/L) of berberine or 1 μmol/L Glibenclamide (GB) for 24 h. Glucose-stimulated insulin secretion (GSIS) assay was conducted and insulin was determined by radioimmunoassay. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to evaluate cytotoxicity. The mRNA level of hepatic nuclear factor 4 alpha (HNF4α) was determined by reverse transcription polymerase chain reaction (RT-PCR). Indirect immunofluorescence staining and Western blot analysis were employed to detect protein expression of HNF4α in the islets. Glucokinase (GK) activity was measured by spectrophotometric method. RESULTS: Berberine enhanced GSIS rather than basal insulin secretion dose-dependently in rat islets and showed no significant cytotoxicity on islet cells at the concentration of 10 μmol/L. Both mRNA and protein expressions of HNF4α were up-regulated by berberine in a dose-dependent manner,and GK activity was also increased accordingly. However,GB demonstrated no regulatory effects on HNF4α expression or GK activity. CONCLUSION: Berberine can enhance GSIS in rat islets,and probably exerts the insulinotropic effect via a pathway involving HNF4α and GK,which is distinct from sulphonylureas (SUs).展开更多
文摘Aim In diabetic patients, metformin appears to provide cardiovascular protection that cannot be attribu- ted only to its antihyperglycemic effects. Metformin is also known as the AMP-activated protein kinase (AMPK) ac- tivator. Our previous study suggested that metformin inhibits transforming growth factor-β1 (TGF-β1) production in a mouse heart failure model of pressure overload. TGF-β1 is a key factor in cardiac fibrosis and is usually induced by Angiotensin Ⅱ (Ang Ⅱ ) in the pressure overload mouse models. This study investigated the effect of metformin on cardiac fibrosis and TGF-β production induced by AngII and the underlying mechanisms. Methods C57/BL6 wild-type and AMPKα2 knockout mice were used. AngII (3 mg · kg-1 · d-1) was infused subcutaneously into mice for 7 days. Adult mouse cardiac fibroblasts were isolated and treated with AngII ( 1 μmol · L-1) and/or met- formin (1 mmol · L-l). Results In C57/BL6 mice, metformin inhibits AngII-induced cardiac fibrosis. In cardi-ac fibroblasts, metformin inhibits TGF-β1 expression and production induced by AngII. AMPK inhibitor, com- pound C, reversed the effects of metformin. In vivo, AMPKα2 deficiency further increases AngII-induced TGF-β1 production. In cardiac fibroblasts, metformin inhibited AngII induced hepatocyte nuclear factor4 (HNF4ot protein level increase and HNF4α binding with TGF-β1 promoter using chromatin immunoprecipitation assay. In vivo, AMPKα2 deficiency further increased AngII-induced HNF4α protein level. Using HNF4α adenovirus, overexpress- ing HNF4α led to a 1.5-fold increase in TGF-β1 mRNA expression. HNF4a siRNA blocked AngII induced TGF- β1 production. Luciferase reporter with deleted HNF4a binding sites showed decreased TGFbl transcriptional activ- ity induced by AngII. In AMPK or2-/- heart, the inhibition of metformin on HNF4a protein was attenuated. Con- clusion Metformin inhibits AngII induced cardiac fibrosis and TGF-β1 production through AMPK activation. The underlying mechanism is that AMPK activation inhibits AngII induced HNF4α and then decreases TGF-β1 expres- sion.
文摘Hepatocyte nuclear factor 4-alpha(HNF4-α)is a nuclear receptor regulating metabolism,cell junctions,differentiation and proliferation in liver and intestinal epithelial cells.Mutations within the HNF4A gene are associated with human diseases such as maturityonset diabetes of the young.Recently,HNF4A has also been described as a susceptibility gene for ulcerative colitis in genome-wide association studies.In addition,specific HNF4A genetic variants have been identified in pediatric cohorts of Crohn’s disease.Results obtained from knockout mice supported that HNF4-αcan protect the intestinal mucosae against inflammation.However,the exact molecular links behind HNF4-αand inflammatory bowel diseases remains elusive.In this review,we will summarize the current knowledge about the role of HNF4-αand its isoforms in inflammation.Specific nature of HNF4-αP1 and P2 classes of isoforms will be summarized.HNF4-αrole as a hepatocyte mediator for cytokines relays during liver inflammation will be integrated based on documented examples of the literature.Conclusions that can be made from these earlier liver studies will serve as a basis to extrapolate correlations and divergences applicable to intestinal inflammation.Finally,potential functional roles for HNF4-αisoforms in protecting the intestinal mucosae from chronic and pathological inflammation will be presented.
文摘Hepatocyte nuclear factor 4-alpha(HNF4α)is a highly conserved member of nuclear receptor superfamily of ligand-dependent transcription factors that is expressed in liver and gastrointestinal organs(pancreas,stomach,and intestine).In liver,HNF4αis best known for its role as a master regulator of liver-specific gene expression and essential for adult and fetal liver function.Dysregulation of HNF4αexpression has been associated with many human diseases such as ulcerative colitis,colon cancer,maturity-onset diabetes of the young,liver cirrhosis,and hepatocellular carcinoma.However,the precise role of HNF4αin the etiology of these human pathogenesis is not well understood.Limited information is known about the role of HNF4αisoforms in liver and gastrointestinal disease progression.There is,therefore,a critical need to know how disruption of the expression of these isoforms may impact on disease progression and phenotypes.In this review,we will update our current understanding on the role of HNF4αin human liver and gastrointestinal diseases.We further provide additional information on possible use of HNF4αas a target for potential therapeutic approaches.
基金Supported by National Natural Science Foundation of China,No.81070359
文摘AIM: To investigate the effect of hepatocyte nuclear factor 4α(HNF4α) on the differentiation and transformation of hepatic stellate cells(HSCs).METHODS: By constructing the recombinant adenovirus vector expressing HNF4α and HNF4αshRNA vector, and manipulating HNF4α expression in HSC-T6 cells, we explored the influence of HNF4α and its induction capacity in the differentiation of rat HSCs into hepatocytes.RESULTS: With increased expression of HNF4αmediated by AdHNF4α, the relative expression of Nanog was downregulated in HSC-T6 cells(98.33 ±12.33 vs 41.33 ± 5.67, P < 0.001). Consequently, the expression of G-P-6 and PEPCK was upregulated(G-P-6:14.34 ± 3.33 vs 42.53 ± 5.87, P < 0.01; PEPCK: 10.10± 4.67 vs 56.56 ± 5.25, P < 0.001), the expression of AFP and ALB was positive, and the expression of Nanog, Type Ⅰ collagen, α-SMA, and TIMP-1 was significantly decreased. HNF4α also downregulated vimentin expression and enhanced E-cadherin expression. The ultrastructure of HNF4α-induced cells had more mitochondria and ribosomes compared with the parental cells. After silencing HNF4α expression,EPCK, E-cadherin, AFP, and ALB were downregulated and α-SMA and vimentin were upregulated.CONCLUSION: HNF4α can induce a tendency of differentiation of HSCs into hepatocyte-like cells. These findings may provide an effective way for the treatmentof liver diseases.
基金Supported by the National Natural Science Foundation of China,No. 81673757 and No. 81573787
文摘BACKGROUND Gastric cancer is the third deadliest cancer in the world and ranks second in incidence and mortality of cancers in China.Despite advances in prevention,diagnosis,and therapy,the absolute number of cases is increasing every year due to aging and the growth of high-risk populations,and gastric cancer is still a leading cause of cancer-related death.Gastric cancer is a consequence of the complex interaction of microbial agents,with environmental and host factors,resulting in the dysregulation of multiple oncogenic and tumor-suppressing signaling pathways.Global efforts have been made to investigate in detail the genomic and epigenomic heterogeneity of this disease,resulting in the identification of new specific and sensitive predictive and prognostic biomarkers.Trastuzumab,a monoclonal antibody against the HER2 receptor,is approved in the first-line treatment of patients with HER2+tumors,which accounts for 13%-23%of the gastric cancer population.Ramucirumab,a monoclonal antibody against VEGFR2,is currently recommended in patients progressing after first-line treatment.Several clinical trials have also tested novel agents for advanced gastric cancer but mostly with dis-appointing results,such as anti-EGFR and anti-MET monoclonal antibodies.Therefore,it is still of great significance to screen specific molecular targets for gastric cancer and drugs directed against the molecular targets.AIM To investigate the effect and mechanism of berberine against tumor growth in gastric cancer xenograft models and to explore the role of hepatocyte nuclear factor 4α(HNF4α)-WNT5a/β-catenin pathways played in the antitumor effects of berberine.METHODS MGC803 and SGC7901 subcutaneous xenograft models were established.The control group was intragastrically administrated with normal saline,and the berberine group was administrated intragastrically with 100 mg/kg/d berberine.The body weight of nude mice during the experiment was measured to assess whether berberine has any adverse reaction.The volume of subcutaneous tumors during this experiment was recorded to evaluate the inhibitory effect of berberine on the growth of MGC803 and SGC7901 subcutaneous transplantation tumors.Polymerase chain reaction assays were conducted to evaluate the alteration of transcriptional expression of HNF4α,WNT5a andβ-catenin in tumor tissues and liver tissues from the MGC803 and SGC7901 xenograft models.Western blotting and IHC were performed to assess the protein expression of HNF4α,WNT5a andβ-catenin in tumor tissues and liver tissues from the MGC803 and SGC7901 xenograft models.RESULTS In the both MGC803 and SGC7901 xenograft tumor models,berberine significantly reduced tumor volume and weight and thus retarded the growth rate of tumors.In the SGC7901 and MGC803 subcutaneously transplanted tumor models,berberine down-regulated the expression of HNF4α,WNT5a andβ-catenin in tumor tissues from both transcription and protein levels.Besides,berberine also suppressed the protein expression of HNF4α,WNT5a andβ-catenin in liver tissues.CONCLUSION Berberine retarded the growth of MGC803 and SGC7901 xenograft model tumors,and the mechanism behind these anti-growth effects might be the downregulation of the expression of HNF4α-WNT5a/β-catenin signaling pathways both in tumor tissues and liver tissues of the xenograft models.
文摘AIM To uncover the role of hepatocyte nuclear factor 4 alpha(HNF4α) in regulating hepatic expression of micro RNAs.METHODS Microarray and real-time PCR were used to determine hepatic expression of micro RNAs in young-adult mice lacking Hnf4α expression in liver(Hnf4α-Liv KO). Integrative genomics viewer software was used to analyze the public chromatin immunoprecipitation-sequencing datasets for DNA-binding of HNF4α, RNA polymerase-Ⅱ, and histone modifications to loci of micro RNAs in mouse liver and human hepatoma cells. Dual-luciferase reporter assay was conducted to determine effects of HNF4α on the promoters of mouse and human micro RNAs as well as effects of micro RNAs on the untranslated regions(3'UTR) of two genes in human hepatoma cells. RESULTS Microarray data indicated that most micro RNAs remained unaltered by Hnf4α deficiency in Hnf4α-Liv KO mice. However, certain liver-predominant micro RNAs were down-regulated similarly in young-adult male and female Hnf4α-Liv KO mice. The down-regulation of mi R-101, mi R-192, mi R-193 a, mi R-194, mi R-215, mi R-802, and mi R-122 as well as induction of mi R-34 and mi R-29 in male Hnf4α-Liv KO mice were confirmed by real-timePCR. Analysis of public chromatin immunoprecipitationsequencing data indicates that HNF4α directly binds to the promoters of mi R-101, mi R-122, mi R-194-2/mi R-192 and mi R-193, which is associated with histone marks of active transcription. Luciferase reporter assay showed that HNF4α markedly activated the promoters of mouse and human mi R-101b/mi R-101-2 and the mi R-194/mi R-192 cluster. Additionally, mi R-192 and mi R-194 significantly decreased activities of luciferase reporters for the 3'UTR of histone H3F3 and chromodomain helicase DNA binding protein 1(CHD1), respectively, suggesting that mi R-192 and mi R-194 might be important in chromosome remodeling through directly targeting H3F3 and CHD1.CONCLUSION HNF4α is essential for hepatic basal expression of a group of liver-enriched micro RNAs, including mi R-101, mi R-192, mi R-193 a, mi R-194 and mi R-802, through which HNF4α may play a major role in the post-transcriptional regulation of gene expression and maintenance of the epigenome in liver.
基金supported by grants from the 973 Program of China (2007CB512902)the National Natural Science Foundation of China (30972622)the National Science and Technology Major Project of China (2008ZX10002-006)
文摘BACKGROUND: Hepatocyte nuclear factor 4 alpha (HNF4α) plays an important role in regulating cytokine-induced inflammatory responses. This study aimed to investigate the role of HNF4α in the development of fulminant hepatic failure (FHF) induced by lipopolysaccharide/D-galactosamine (LPS/D-GalN). METHODS: The FHF model was induced by simultaneous intraperitoneal injection of LPS/D-GalN in mice. Three days prior to LPS/D-GalN administration, HNF4α short-hairpin interfering RNA expression plasmid or physiological saline was injected via the tail vein with a hydrodynamics-based procedure. The degree of hepatic damage and cumulative survival rate were subsequently assessed. RESULTS: The expression of HNF4α was increased in the early stage after LPS/D-GalN administration. Inhibiting the expression of HNF4α reduced serum levels of alanine aminotransferase and aspartate aminotransferase, alleviated histological injury, and improved the survival of mice with FHF. In addition, both serum and hepatic tumor necrosis factor alpha expression were suppressed when HNF4α expression was inhibited in mice with FHF. CONCLUSION: Inhibiting HNF4α expression protects mice from FHF induced by LPS/D-GalN, but the exact mechanism behind this needs further investigation.
基金Supported by National Natural Science Foundation of China,No.81673757.
文摘BACKGROUND Gastric cancer(GC)is the second most common cause of cancer-related deaths worldwide.Hepatocyte nuclear factor 4 alpha(HNF4α)that belongs to the nuclear hormone receptor superfamily,is overexpressed in GC tissues,and might be involved in the development of GC by regulating its downstream winglessrelated integration site(WNT)/β-catenin signaling.AIM To clarify the expression of HNF4α/WNT5a/β-catenin signaling proteins in clinical GC tissues.METHODS We immunohistochemically stained pathological blocks of GC and matched paracancerous tissues.The intensity of HNF4α,WNT5a andβ-catenin staining in the tumor cells was determined according to cell rates and staining intensity.The correlations between GC and HNF4α,WNT5a,andβ-catenin expression using chisquare and paired chi-square tests.Relationships between double-positive HNF4αand WNT5a expression and types of gastric tumor tissues were assessed using regression analysis.Correlations between HNF4αand WNT5a expression at the RNA level in GC tissues found in the TCGA database were analyzed using Pearson correlation coefficients.RESULTS We found more abundant HNF4αand WNT5a proteins in GC,especially in mucinous adenocarcinoma and mixed GC than in adjacent tissues(P<0.001).Low and high levels of cytoplasmicβ-catenin respectively expressed in GC and adjacent tissues(P<0.001)were not significantly associated with pathological parameters.CONCLUSION The expressions of HNF4αand WNT5a could serve as early diagnostic biomarkers for GC.
文摘BACKGROUND Intravenous steroid pulse therapy is the treatment of choice for acute exacerbation of multiple sclerosis(MS).Although steroid administration is generally welltolerated,cases of cardiac arrhythmia have been reported.Herein,we describe a young woman who developed marked sinus bradycardia and T-wave abnormalities after corticosteroid administration.We also present plausible explanations for the abnormalities observed in this patient.CASE SUMMARY An 18-year-old woman experienced vertiginous dizziness and binocular diplopia 1 wk prior to admission.Neurological examination revealed left internuclear ophthalmoplegia with left peripheral-type facial palsy.The initial laboratory results were consistent with those of type 2 diabetes.Brain magnetic resonance imaging revealed multifocal,non-enhancing,symptomatic lesions and multiple enhancing lesions.She was diagnosed with MS and maturity-onset diabetes of the young.Intravenous methylprednisolone was administered.On day 5 after methylprednisolone infusion,marked bradycardia with T-wave abnormalities were observed.Genetic evaluation to elucidate the underlying conditions revealed a hepatocyte nuclear factor 4-alpha(HNF4A)gene mutation.Steroid treatment was discontinued under suspicion of corticosteroid-induced bradycardia.Her electrocardiogram changes returned to normal without complications two days after steroid discontinuation.CONCLUSION Corticosteroid-induced bradycardia may have a significant clinical impact,especially in patients with comorbidities,such as HNF4A mutations.
基金supported by the National Natural Science Foundation of China(No.81300345).
文摘Limited treatment options are available for hepatocellular carcinoma(HCC),especially in the advanced stage,which is associated with a poor prognosis.Many studies have demonstrated that hepatocyte nuclear factor 4α(HNF 4α)plays an important role in hepatic differentiation and the carcinogenesis of HCC.HNF 4αcritically regulates hepatic differentiation by controlling a large number of genes involved in hepatic functions including metabolism,xenobiotic detoxification,bile acid synthesis,and serum protein production.It has also been confirmed to play an important role in the inflammatory environment in HCC.Thus,HNF 4αis considered to be a promising target for the treatment of HCC.Some studies have demonstrated that regulating HNF 4αexpression in HCC had beneficial effects in in vivo and in vitro experiments.We herein review the role of HNF 4αin regulating hepatic metabolism and the inflammatory response,aiming to provide some ideas on induced hepatic differentiation therapy and regulating the inflammatory microenvironment for the treatment of advanced HCC.
基金Supported by Jinling Hospital Research Fund,No.2013064
文摘AIM To determine the effects of ω-3 fatty acids(ω-3FA) on the toll-like receptor 4(TLR4)/nuclear factor κB p56(NF-κBp56) signal pathway in the lungs of rats with severe acute pancreatitis(SAP).METHODS A total of 56 Sprague-Dawley rats were randomly divided into 4 groups: control group, SAP-saline group, SAP-soybean oil group and SAP-ω-3FA group. SAP was induced by the retrograde infusion of sodium taurocholate into the pancreatic duct. The expression of TLR4 and NF-κBp56 in the lungs was evaluated by immunohistochemistry and Western blot analysis. The levels of inflammatory cytokines interleukin-6 and tumor necrosis factor-alpha in the lungs were measured by enzyme-linked immunosorbent assay. RESULTS The expression of TLR4 and NF-κBp56 in lungs and of inflammatory cytokines in serum significantly increased in the SAP group compared with the control group(P < 0.05), but was significantly decreased in the ω-3FA group compared with the soybean oil group at 12 and 24 h(P < 0.05).CONCLUSION During the initial stage of SAP, ω-3FA can efficiently lower the inflammatory response and reduce lung injury by triggering the TLR4/NF-κBp56 signal pathway.
基金This research was supported by the National 973 Program (2006 CB503901) the Major Project of Shanghai Science and Technology Development Foundation (02DJ14052-I)+1 种基金the Science and Technology Development Foundation of Shanghai Municipal Health Bureau (034043) the Young Doctor Training Project of Shanghai Municipal Health Bureau
文摘Objective To analyze the association of variants of hepatocyte nuclear factor-1α (HNF-1α) gene with type 2 diabetes in Chinese population. Methods In 152 unrelated type 2 diabetes patients and 93 unrelated controls, eleven single nucleotide polymorphisms (SNPs) were identified and genotyped. Statistical analyses were performed to investigate whether these SNPs were associated with diabetes status in our samples. Results In the individual SNP study, no SNP differed significantly in frequency between type 2 diabetes patients and controls. In the haplotype analysis, two haplotype blocks were identified. In haplotype block 1, no evidence was found between common HNF-1α haplotypes and type 2 diabetes. However, in haplotype block 2, a common haplotype GCGC formed by four tagging SNPs (tSNPs) was found to be associated with decreased risk of type 2 diabetes (odds ratio [OR] 0.6011, 95% confidence interval [CI] 0.4138-0.8732, P=0.0073, empirical P=0.0511, permutation test). A similar trend was also observed in the diplotype analysis, indicating that the increasing copy number of the haplotype GCGC was associated with the decreased frequency of diabetes (P=0.0193). Conclusion The results of this study provide evidence that the haplotype of HNF-1α decreases the risk of type 2 diabetes in Chinese individuals.
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The National Natural Science Foundation of China,No.30500685
文摘AIM: To observe the effect of berberine on insulin secretion in rat pancreatic islets and to explore its possible molecular mechanism. METHODS: Primary rat islets were isolated from male Sprague-Dawley rats by collagenase digestion and treated with different concentrations (1,3,10 and 30 μmol/L) of berberine or 1 μmol/L Glibenclamide (GB) for 24 h. Glucose-stimulated insulin secretion (GSIS) assay was conducted and insulin was determined by radioimmunoassay. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to evaluate cytotoxicity. The mRNA level of hepatic nuclear factor 4 alpha (HNF4α) was determined by reverse transcription polymerase chain reaction (RT-PCR). Indirect immunofluorescence staining and Western blot analysis were employed to detect protein expression of HNF4α in the islets. Glucokinase (GK) activity was measured by spectrophotometric method. RESULTS: Berberine enhanced GSIS rather than basal insulin secretion dose-dependently in rat islets and showed no significant cytotoxicity on islet cells at the concentration of 10 μmol/L. Both mRNA and protein expressions of HNF4α were up-regulated by berberine in a dose-dependent manner,and GK activity was also increased accordingly. However,GB demonstrated no regulatory effects on HNF4α expression or GK activity. CONCLUSION: Berberine can enhance GSIS in rat islets,and probably exerts the insulinotropic effect via a pathway involving HNF4α and GK,which is distinct from sulphonylureas (SUs).