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 HNF4...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 maturity-onset 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-α can protect the intestinal mucosae against inflammation. However, the exact molecular links behind HNF4-α and inflammatory bowel diseases remains elusive. In this review, we will summarize the current knowledge about the role of HNF4-α and its isoforms in inflammation. Specific nature of HNF4-α P1 and P2 classes of isoforms will be summarized. HNF4-α role 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-α isoforms in protecting the intestinal mucosae from chronic and pathological inflammation will be presented.展开更多
AIMTo uncover the role of hepatocyte nuclear factor 4 alpha (HNF4α) in regulating hepatic expression of microRNAs. METHODSMicroarray and real-time PCR were used to determine hepatic expression of microRNAs in young-a...AIMTo uncover the role of hepatocyte nuclear factor 4 alpha (HNF4α) in regulating hepatic expression of microRNAs. METHODSMicroarray and real-time PCR were used to determine hepatic expression of microRNAs in young-adult mice lacking Hnf4α expression in liver (Hnf4α-LivKO). 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 microRNAs 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 microRNAs as well as effects of microRNAs on the untranslated regions (3’UTR) of two genes in human hepatoma cells. RESULTSMicroarray data indicated that most microRNAs remained unaltered by Hnf4α deficiency in Hnf4α-LivKO mice. However, certain liver-predominant microRNAs were down-regulated similarly in young-adult male and female Hnf4α-LivKO mice. The down-regulation of miR-101, miR-192, miR-193a, miR-194, miR-215, miR-802, and miR-122 as well as induction of miR-34 and miR-29 in male Hnf4α-LivKO mice were confirmed by real-time PCR. Analysis of public chromatin immunoprecipitation-sequencing data indicates that HNF4α directly binds to the promoters of miR-101, miR-122, miR-194-2/miR-192 and miR-193, which is associated with histone marks of active transcription. Luciferase reporter assay showed that HNF4α markedly activated the promoters of mouse and human miR-101b/miR-101-2 and the miR-194/miR-192 cluster. Additionally, miR-192 and miR-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 miR-192 and miR-194 might be important in chromosome remodeling through directly targeting H3F3 and CHD1. CONCLUSIONHNF4α is essential for hepatic basal expression of a group of liver-enriched microRNAs, including miR-101, miR-192, miR-193a, miR-194 and miR-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 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
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
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 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
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
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 observe the effect of berberine on insulin secretion in rat pancreatic islets and to explore its possible molecular mechanism. METHODS: Pdmary rat islets were isolated from male Sprague-Dawley rats by collag...AIM: To observe the effect of berberine on insulin secretion in rat pancreatic islets and to explore its possible molecular mechanism. METHODS: Pdmary 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 (HAIF4α) 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
Pregnancy in women with monogenic diabetes is potentially complex,with significant implications for both maternal and fetal health.Among these,maturity-onset diabetes of the young(MODY)stands out as a prevalent monoge...Pregnancy in women with monogenic diabetes is potentially complex,with significant implications for both maternal and fetal health.Among these,maturity-onset diabetes of the young(MODY)stands out as a prevalent monogenic diabetes subtype frequently encountered in clinical practice.Each subtype of MODY requires a distinct approach tailored to the pregnancy,diverging from management strategies in non-pregnant individuals.Glucokinase MODY(GCK-MODY)typically does not require treatment outside of pregnancy,but special considerations arise when a woman with GCK-MODY becomes pregnant.The glycemic targets in GCK-MODY pregnancies are not exclusively dictated by the maternal/paternal MODY genotype but are also influenced by the genotype of the developing fetus.During pregnancy,the choice between sulfonylurea or insulin for treating hepatocyte nuclear factor 1-alpha(HNF1A)-MODY and HNF4A-MODY depends on the mother’s specific circumstances and the available expertise.Management of other rarer MODY subtypes is individu-alized,with decisions made on a case-by-case basis.Therefore,a collaborative approach involving expert diabetes and obstetric teams is crucial for the compre-hensive management of MODY pregnancies.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
Non-alcoholic fatty liver disease (NAFLD) is emerging as the most common chronic liver disease worldwide. It refers to a range of liver conditions affecting people who drink little or no alcohol. NAFLD comprises non-a...Non-alcoholic fatty liver disease (NAFLD) is emerging as the most common chronic liver disease worldwide. It refers to a range of liver conditions affecting people who drink little or no alcohol. NAFLD comprises non-alcoholic fatty liver and non-alcoholic steatohepatitis (NASH), the more aggressive form of NAFLD. NASH is featured by steatosis, lobular inflammation, hepatocyte injury, and various degrees of fibrosis. Although much progress has been made over the past decades, the pathogenic mechanism of NAFLD remains to be fully elucidated. Hepatocyte nuclear factor 4α (HNF4α) is a nuclear hormone receptor that is highly expressed in hepatocytes. Hepatic HNF4α expression is markedly reduced in NAFLD patients and mouse models of NASH. HNF4α has been shown to regulate bile acid, lipid, glucose, and drug metabolism. In this review, we summarize the recent advances in the understanding of the pathogenesis of NAFLD with a focus on the regulation of HNF4α and the role of hepatic HNF4α in NAFLD. Several lines of evidence have shown that hepatic HNF4α plays a key role in the initiation and progression of NAFLD. Recent data suggest that hepatic HNF4α may be a promising target for treatment of NAFLD.展开更多
AIM: To investigate the differentiation status and key factors to facilitate hepatic differentiation of human bone-marrow-derived mesenchymal stem cells (MSCs). METHODS: Human MSCs derived from bone marrow were induce...AIM: To investigate the differentiation status and key factors to facilitate hepatic differentiation of human bone-marrow-derived mesenchymal stem cells (MSCs). METHODS: Human MSCs derived from bone marrow were induced into hepatocyte-like cells following a previously published protocol. The differentiation status of the hepatocyte-like cells was compared with various human hepatoma cell lines. Overexpression of hepatocyte nuclear factor (HNF)-4α was mediated by adenovirus infection of these hepatocyte-like cells. The expression of interesting genes was then examined by either re-verse transcription-polymerase chain reaction (RT-PCR) or real-time RT-PCR methods. RESULTS: Our results demonstrated that the differentiation status of hepatocyte-like cells induced from human MSCs was relatively similar to poorly differentiated human hepatoma cell lines. Interestingly, the HNF-4 isoform in induced MSCs and poorly differentiated human hepatoma cell lines was identified as HNF4γ instead of HNF-4α. Overexpression of HNF-4α in induced MSCs significantly enhanced the expression level of hepatic-specific genes, liver-enriched transcription factors, and cytochrome P450 (P450) genes. CONCLUSION: Overexpression of HNF-4α improves the hepatic differentiation of human MSCs from bone marrow and is a simple way of providing better cell sources for clinical applications.展开更多
Gastric intestinal metaplasia(GIM)is a precancerous lesion of gastric cancer(GC)and is considered an irreversible point of progression for GC.Helicobacter pylori infection can cause GIM,but its eradication still does ...Gastric intestinal metaplasia(GIM)is a precancerous lesion of gastric cancer(GC)and is considered an irreversible point of progression for GC.Helicobacter pylori infection can cause GIM,but its eradication still does not reverse the process.Bile reflux is also a pathogenic factor in GIM and can continuously irritate the gastric mucosa,and bile acids in refluxed fluid have been widely reported to be associated with GIM.This paper reviews in detail the relationship between bile reflux and GIM and the mechanisms by which bile acids induce GIM.展开更多
Drug-induced hyperglycemia/diabetes is a global issue. Some drugs induce hyperglycemia by activating the pregnane X receptor(PXR), but the mechanism is unclear. Here, we report that PXR activation induces hyperglycemi...Drug-induced hyperglycemia/diabetes is a global issue. Some drugs induce hyperglycemia by activating the pregnane X receptor(PXR), but the mechanism is unclear. Here, we report that PXR activation induces hyperglycemia by impairing hepatic glucose metabolism due to inhibition of the hepatocyte nuclear factor 4-alpha(HNF4 a)-glucose transporter 2(GLUT2) pathway. The PXR agonists atorvastatin and rifampicin significantly downregulated GLUT2 and HNF4 a expression, and impaired glucose uptake and utilization in HepG2 cells. Overexpression of PXR downregulated GLUT2 and HNF4 a expression, while silencing PXR upregulated HNF4 a and GLUT2 expression.Silencing HNF4 a decreased GLUT2 expression, while overexpressing HNF4 a increased GLUT2 expression and glucose uptake. Silencing PXR or overexpressing HNF4 a reversed the atorvastatininduced decrease in GLUT2 expression and glucose uptake. In human primary hepatocytes, atorvastatin downregulated GLUT2 and HNF4 a mRNA expression, which could be attenuated by silencing PXR. Silencing HNF4 a downregulated GLUT2 mRNA expression. These findings were reproduced with mouse primary hepatocytes. Hnf4 a plasmid increased Slc2 a2 promoter activity. Hnf4 a silencing or pregnenolone-16 a-carbonitrile(PCN) suppressed the Slc2 a2 promoter activity by decreasing HNF4 a recruitment to the Slc2 a2 promoter. Liver-specific Hnf4 a deletion and PCN impaired glucose tolerance and hepatic glucose uptake, and decreased the expression of hepatic HNF4 a and GLUT2. In conclusion, PXR activation impaired hepatic glucose metabolism partly by inhibiting the HNF4 aGLUT2 pathway. These results highlight the molecular mechanisms by which PXR activators induce hyperglycemia/diabetes.展开更多
Hepatitis B virus(HBV)is a primary cause of chronic liver diseases in humans.HBV infection exhibits strict host and tissue tropism.HBV core promoter(Cp)drives transcription of pregenomic RNA(pg RNA)and plays a key rol...Hepatitis B virus(HBV)is a primary cause of chronic liver diseases in humans.HBV infection exhibits strict host and tissue tropism.HBV core promoter(Cp)drives transcription of pregenomic RNA(pg RNA)and plays a key role in the viral life cycle.Hepatocyte nuclear factor 4α(HNF4α)acts as a major transcriptional factor that stimulates Cp.In this work,we reported that BEL7404 cell line displayed a high efficiency of DNA transfection and high levels of HBV antigen expression after transfection of HBV replicons without prominent viral replication.The introduction of exogenous HNF4αand human sodium taurocholate cotransporting polypeptide(h NTCP)expression into BEL7404made it permissive for HBV replication and susceptible to HBV infection.BEL7404-derived cell lines with induced HBV permissiveness and susceptibility were constructed by stable co-transfection of h NTCP and Tet-inducible HNF4αfollowed by limiting dilution cloning.HBV replication in such cells was sensitive to inhibition by nucleotide analog tenofovir,while the infection was inhibited by HBV entry inhibitors.This cell culture system provides a new and additional tool for the study of HBV replication and infection as well as the characterization of antiviral agents.展开更多
Objective To investigate the possible protective effects of sophocarpine on mucosal injury and epithelial barrier disruption on dextran sulfate sodium (DSS)-induced acute colitis. Methods Male BALB/c mice were rando...Objective To investigate the possible protective effects of sophocarpine on mucosal injury and epithelial barrier disruption on dextran sulfate sodium (DSS)-induced acute colitis. Methods Male BALB/c mice were randomly divided into three groups. The mice in normal group were given normal water, and those in model and sophocarpine- treated groups were given 2.5% DSS for 6 d to induce acute colitis. Sophocarpine (30 mg/kg) was ip administered once daily during the study period. Severity of colitis was evaluated by disease activity index (DAI), histological injury and inflammatory cytokine production including tumor necrosis factor-α (TNF-α), interleukin-lβ (IL-Iβ), and monocyte chemoattractant protein-1 (MCP-1). The colonic barrier disruption was assessed by testing the expression of junctional adhesion molecule-1 (JAM-1), E-cadherin (E-CAD), and desmocollin-2 (DSC-2) in colon mucosa. Expression of HNF4~ in colon mucosa was detected by immunohistochemistry staining and real-time RT-PCR, respectively. Results Compared with normal group, DAI, colonic shortening, and histopathological injury in model group were elevated (P 〈 0.05), but reduced in sophocarpine-treated group (P 〈 0.05). Compared with model group, the mRNA expression of inflammatory cytokines (TNF-α, IL-16, MCP-1) were obviously lower in sophocarpine-treated group (P 〈 0.05), while the cellular junction proteins (E-CAD, JAM-l, and DSC-2) were higher (P 〈 0.05). The expression of HNF4α at mRNA and protein levels was decreased significantly in model group, but increased apparently in sophocarpine-treated group. Conclusion Sophocarpine can enhance the expression of HNF4α, promote the expression of colonic intrecellular junctions, thus, maintain the integrity of the colonic barrier and inhibit the colitis process. We suggest that sophocarpine could enhance the production of cellular junction proteins to protect the intestinal barrier fuction, at least partly, in HNF4α-dependent pathway.展开更多
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 maturity-onset 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-α can protect the intestinal mucosae against inflammation. However, the exact molecular links behind HNF4-α and inflammatory bowel diseases remains elusive. In this review, we will summarize the current knowledge about the role of HNF4-α and its isoforms in inflammation. Specific nature of HNF4-α P1 and P2 classes of isoforms will be summarized. HNF4-α role 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-α isoforms in protecting the intestinal mucosae from chronic and pathological inflammation will be presented.
文摘AIMTo uncover the role of hepatocyte nuclear factor 4 alpha (HNF4α) in regulating hepatic expression of microRNAs. METHODSMicroarray and real-time PCR were used to determine hepatic expression of microRNAs in young-adult mice lacking Hnf4α expression in liver (Hnf4α-LivKO). 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 microRNAs 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 microRNAs as well as effects of microRNAs on the untranslated regions (3’UTR) of two genes in human hepatoma cells. RESULTSMicroarray data indicated that most microRNAs remained unaltered by Hnf4α deficiency in Hnf4α-LivKO mice. However, certain liver-predominant microRNAs were down-regulated similarly in young-adult male and female Hnf4α-LivKO mice. The down-regulation of miR-101, miR-192, miR-193a, miR-194, miR-215, miR-802, and miR-122 as well as induction of miR-34 and miR-29 in male Hnf4α-LivKO mice were confirmed by real-time PCR. Analysis of public chromatin immunoprecipitation-sequencing data indicates that HNF4α directly binds to the promoters of miR-101, miR-122, miR-194-2/miR-192 and miR-193, which is associated with histone marks of active transcription. Luciferase reporter assay showed that HNF4α markedly activated the promoters of mouse and human miR-101b/miR-101-2 and the miR-194/miR-192 cluster. Additionally, miR-192 and miR-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 miR-192 and miR-194 might be important in chromosome remodeling through directly targeting H3F3 and CHD1. CONCLUSIONHNF4α is essential for hepatic basal expression of a group of liver-enriched microRNAs, including miR-101, miR-192, miR-193a, miR-194 and miR-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 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.
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 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.
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 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.
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: Pdmary 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 (HAIF4α) 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).
文摘Pregnancy in women with monogenic diabetes is potentially complex,with significant implications for both maternal and fetal health.Among these,maturity-onset diabetes of the young(MODY)stands out as a prevalent monogenic diabetes subtype frequently encountered in clinical practice.Each subtype of MODY requires a distinct approach tailored to the pregnancy,diverging from management strategies in non-pregnant individuals.Glucokinase MODY(GCK-MODY)typically does not require treatment outside of pregnancy,but special considerations arise when a woman with GCK-MODY becomes pregnant.The glycemic targets in GCK-MODY pregnancies are not exclusively dictated by the maternal/paternal MODY genotype but are also influenced by the genotype of the developing fetus.During pregnancy,the choice between sulfonylurea or insulin for treating hepatocyte nuclear factor 1-alpha(HNF1A)-MODY and HNF4A-MODY depends on the mother’s specific circumstances and the available expertise.Management of other rarer MODY subtypes is individu-alized,with decisions made on a case-by-case basis.Therefore,a collaborative approach involving expert diabetes and obstetric teams is crucial for the compre-hensive management of MODY pregnancies.
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.
基金This work is supported by the grants from National Institutes of Health(R01DK102619, R01DK118941, R01DK118805, and R0DK121548)。
文摘Non-alcoholic fatty liver disease (NAFLD) is emerging as the most common chronic liver disease worldwide. It refers to a range of liver conditions affecting people who drink little or no alcohol. NAFLD comprises non-alcoholic fatty liver and non-alcoholic steatohepatitis (NASH), the more aggressive form of NAFLD. NASH is featured by steatosis, lobular inflammation, hepatocyte injury, and various degrees of fibrosis. Although much progress has been made over the past decades, the pathogenic mechanism of NAFLD remains to be fully elucidated. Hepatocyte nuclear factor 4α (HNF4α) is a nuclear hormone receptor that is highly expressed in hepatocytes. Hepatic HNF4α expression is markedly reduced in NAFLD patients and mouse models of NASH. HNF4α has been shown to regulate bile acid, lipid, glucose, and drug metabolism. In this review, we summarize the recent advances in the understanding of the pathogenesis of NAFLD with a focus on the regulation of HNF4α and the role of hepatic HNF4α in NAFLD. Several lines of evidence have shown that hepatic HNF4α plays a key role in the initiation and progression of NAFLD. Recent data suggest that hepatic HNF4α may be a promising target for treatment of NAFLD.
基金Supported by Grant MG-098-PP-08 from the National Health Research Institutes, Taiwan
文摘AIM: To investigate the differentiation status and key factors to facilitate hepatic differentiation of human bone-marrow-derived mesenchymal stem cells (MSCs). METHODS: Human MSCs derived from bone marrow were induced into hepatocyte-like cells following a previously published protocol. The differentiation status of the hepatocyte-like cells was compared with various human hepatoma cell lines. Overexpression of hepatocyte nuclear factor (HNF)-4α was mediated by adenovirus infection of these hepatocyte-like cells. The expression of interesting genes was then examined by either re-verse transcription-polymerase chain reaction (RT-PCR) or real-time RT-PCR methods. RESULTS: Our results demonstrated that the differentiation status of hepatocyte-like cells induced from human MSCs was relatively similar to poorly differentiated human hepatoma cell lines. Interestingly, the HNF-4 isoform in induced MSCs and poorly differentiated human hepatoma cell lines was identified as HNF4γ instead of HNF-4α. Overexpression of HNF-4α in induced MSCs significantly enhanced the expression level of hepatic-specific genes, liver-enriched transcription factors, and cytochrome P450 (P450) genes. CONCLUSION: Overexpression of HNF-4α improves the hepatic differentiation of human MSCs from bone marrow and is a simple way of providing better cell sources for clinical applications.
基金supported by grants from the National Natural Science Foundation of China(No.8217031045 and No.81873554 to YQS).
文摘Gastric intestinal metaplasia(GIM)is a precancerous lesion of gastric cancer(GC)and is considered an irreversible point of progression for GC.Helicobacter pylori infection can cause GIM,but its eradication still does not reverse the process.Bile reflux is also a pathogenic factor in GIM and can continuously irritate the gastric mucosa,and bile acids in refluxed fluid have been widely reported to be associated with GIM.This paper reviews in detail the relationship between bile reflux and GIM and the mechanisms by which bile acids induce GIM.
基金supported by the National Natural Science Foundation of China (Nos.81673505,81872930,and 82073922)the “Double First-Class” university project (No.CPU2018GY22,China)“333” Project of Jiangsu Province (No.BRA2020287,China)。
文摘Drug-induced hyperglycemia/diabetes is a global issue. Some drugs induce hyperglycemia by activating the pregnane X receptor(PXR), but the mechanism is unclear. Here, we report that PXR activation induces hyperglycemia by impairing hepatic glucose metabolism due to inhibition of the hepatocyte nuclear factor 4-alpha(HNF4 a)-glucose transporter 2(GLUT2) pathway. The PXR agonists atorvastatin and rifampicin significantly downregulated GLUT2 and HNF4 a expression, and impaired glucose uptake and utilization in HepG2 cells. Overexpression of PXR downregulated GLUT2 and HNF4 a expression, while silencing PXR upregulated HNF4 a and GLUT2 expression.Silencing HNF4 a decreased GLUT2 expression, while overexpressing HNF4 a increased GLUT2 expression and glucose uptake. Silencing PXR or overexpressing HNF4 a reversed the atorvastatininduced decrease in GLUT2 expression and glucose uptake. In human primary hepatocytes, atorvastatin downregulated GLUT2 and HNF4 a mRNA expression, which could be attenuated by silencing PXR. Silencing HNF4 a downregulated GLUT2 mRNA expression. These findings were reproduced with mouse primary hepatocytes. Hnf4 a plasmid increased Slc2 a2 promoter activity. Hnf4 a silencing or pregnenolone-16 a-carbonitrile(PCN) suppressed the Slc2 a2 promoter activity by decreasing HNF4 a recruitment to the Slc2 a2 promoter. Liver-specific Hnf4 a deletion and PCN impaired glucose tolerance and hepatic glucose uptake, and decreased the expression of hepatic HNF4 a and GLUT2. In conclusion, PXR activation impaired hepatic glucose metabolism partly by inhibiting the HNF4 aGLUT2 pathway. These results highlight the molecular mechanisms by which PXR activators induce hyperglycemia/diabetes.
基金the National Natural Science Foundation of China(81971921,81971931)the National base cultivation project(20DZ2210404)the Major science and technology project for the prevention and treatment of major infectious diseases(2018ZX10301208)。
文摘Hepatitis B virus(HBV)is a primary cause of chronic liver diseases in humans.HBV infection exhibits strict host and tissue tropism.HBV core promoter(Cp)drives transcription of pregenomic RNA(pg RNA)and plays a key role in the viral life cycle.Hepatocyte nuclear factor 4α(HNF4α)acts as a major transcriptional factor that stimulates Cp.In this work,we reported that BEL7404 cell line displayed a high efficiency of DNA transfection and high levels of HBV antigen expression after transfection of HBV replicons without prominent viral replication.The introduction of exogenous HNF4αand human sodium taurocholate cotransporting polypeptide(h NTCP)expression into BEL7404made it permissive for HBV replication and susceptible to HBV infection.BEL7404-derived cell lines with induced HBV permissiveness and susceptibility were constructed by stable co-transfection of h NTCP and Tet-inducible HNF4αfollowed by limiting dilution cloning.HBV replication in such cells was sensitive to inhibition by nucleotide analog tenofovir,while the infection was inhibited by HBV entry inhibitors.This cell culture system provides a new and additional tool for the study of HBV replication and infection as well as the characterization of antiviral agents.
文摘Objective To investigate the possible protective effects of sophocarpine on mucosal injury and epithelial barrier disruption on dextran sulfate sodium (DSS)-induced acute colitis. Methods Male BALB/c mice were randomly divided into three groups. The mice in normal group were given normal water, and those in model and sophocarpine- treated groups were given 2.5% DSS for 6 d to induce acute colitis. Sophocarpine (30 mg/kg) was ip administered once daily during the study period. Severity of colitis was evaluated by disease activity index (DAI), histological injury and inflammatory cytokine production including tumor necrosis factor-α (TNF-α), interleukin-lβ (IL-Iβ), and monocyte chemoattractant protein-1 (MCP-1). The colonic barrier disruption was assessed by testing the expression of junctional adhesion molecule-1 (JAM-1), E-cadherin (E-CAD), and desmocollin-2 (DSC-2) in colon mucosa. Expression of HNF4~ in colon mucosa was detected by immunohistochemistry staining and real-time RT-PCR, respectively. Results Compared with normal group, DAI, colonic shortening, and histopathological injury in model group were elevated (P 〈 0.05), but reduced in sophocarpine-treated group (P 〈 0.05). Compared with model group, the mRNA expression of inflammatory cytokines (TNF-α, IL-16, MCP-1) were obviously lower in sophocarpine-treated group (P 〈 0.05), while the cellular junction proteins (E-CAD, JAM-l, and DSC-2) were higher (P 〈 0.05). The expression of HNF4α at mRNA and protein levels was decreased significantly in model group, but increased apparently in sophocarpine-treated group. Conclusion Sophocarpine can enhance the expression of HNF4α, promote the expression of colonic intrecellular junctions, thus, maintain the integrity of the colonic barrier and inhibit the colitis process. We suggest that sophocarpine could enhance the production of cellular junction proteins to protect the intestinal barrier fuction, at least partly, in HNF4α-dependent pathway.