HNF4α Expression Research Articles

A50 PRODUCTION OF A PANCREATIC AND INTESTINAL HEPATOCYTE NUCLEAR FACTOR 4A DOUBLE KNOCKOUT MOUSE MODEL TO UNRAVEL NEW MECHANISMS CONTROLLING METABOLISM

Abstract Background Hepatocyte nuclear factor (HNF) 4A is a transcription factor mainly found within endodermal organs, including the intestine and pancreas. HNF4A controls the expression of genes associated with glucose transit, glycolytic enzymes, lipid and drug metabolism, and incretin production from intestinal enteroendocrine cells. Mutations within this are linked to various diseases, including maturity-onset diabetes of the young and increased risk of Type 2 diabetes mellitus. However, it remains unclear whether intestinal and pancreatic HNF4A is functionally involved in glucose metabolism. This could be partly due to the lack of suitable experimental model that allow recreating phenotypes associated with hnf4a lost in two key organs involved in controlling body glucose levels. Aims To generate a conditionally mutant mouse line that does not express HNF4A in the intestine or the pancreas and to investigate how glucose metabolism is affected in these mice. Methods Conditional deletion in each organ was achieved by mating VillinCre or InsCreER with Hnf4αloxP/loxP C57BL/6 mice, respectively. The mutant mouse line was then generated by crossing mice Hnf4αloxP/loxP+VillinCre and Hnf4αloxP/loxP+InsCreER. PCR was performed to confirm all genotypes. Male and female mice around 2-3 months were distributed in four groups, including controls, Hnf4α-deleted intestine only, Hnf4α-deleted pancreas only, and Hnf4α-deleted in both organs. HNF4A expression was measured by qPCR, immunoblot and immunofluorescence. Glucose metabolism tests, including oral glucose tolerance (2g/kg) and insulin tolerance (0.75 International Units/kg) were performed. The blood glucose levels were measured after overnight fasting at 15, 30, 60, and 120 min. Results The body weight of four groups of mice remained comparable over experimental time. HNF4A expression was not detected from double mutant mice’s gut epithelial or pancreatic β cells. The oral glucose challenge showed a difference among the group of experimental mice as compared to the control group. After 15 min, blood glucose values of double mutant mice remained higher than control mice, for which glucose clearance was less efficient in the mutants. Insulin tolerance tests demonstrated that double mutant mice behave differently than control mice, suggesting a defect in insulin response. Conclusions These promising preliminary results allow us to obtain and characterize a novel murine model to study glucose metabolic syndrome that could be related to hnf4a gene deletion in both the gut and pancreas. Further studies are needed to establish a mechanism by which the HNF4A transcription factor could interplay between the intestine and the pancreas during whole-body glucose metabolism. Funding Agencies CIHRBourses d’excellence de l'Université de Sherbrooke

Studies on the Effect of Piperine on Hepatocyte Nuclear Factor 1 Alpha (HNF-1α) and Sterol Regulatory Element-Binding Protein 1c (SREBP-1c) Levels in High-Fat-Diet and Sucrose-Induced Type 2 Diabetes Mellitus Rats.

Piperine, a naturally occurring compound in black pepper (Piper nigrum), is known for its potential health benefits, including its reported enhancement of insulin sensitivity. However, the precise impact of piperine on hepatocyte nuclear factor 1 alpha (HNF-1α) and sterol regulatory element-binding protein 1c (SREBP-1c), transcription factors for insulin signaling and glucose metabolism in hepatocytes, remains unclear. This study aims to investigate the effect of piperine, compared to metformin, on blood glucose and insulin levels by modifying the expression of hepatic HNF-1α and SREBP-1c in high-fat-diet (HFD) and sucrose-induced type 2 diabetes mellitus (T2DM) rats and in human Chang liver cells. Adult male albino rats were categorized into four groups: group 1 as the control, group 2 as T2DM, group 3 as T2DM rats treated with piperine (40 mg), and group 4 as T2DM rats treated with metformin (50 mg). Fasting blood glucose (FBG) and serum insulin levels were measured using enzyme-linked immunosorbent assay (ELISA), while real-time polymerase chain reaction (RT-PCR) analysis was conducted to assess the mRNA expression of HNF-1α and SREBP-1c. Further, piperine was treated with normal and high glucose-induced Chang liver cells, and gene expression was analysed.Data analysis was performed using one-way analysis of variance (ANOVA), with a significance set at p<0.05. Treatment with piperine led to a notable decrease in blood glucose levels and circulating insulin when compared with T2DM rats (group 2). Additionally, piperine administration resulted in the upregulation of HNF-1α mRNA expression and downregulation of SREBP-1c mRNA levels whose effects were found to be near that of the control and standard drug metformin's effects. In vitro study also confirmed that piperine improved the HNF-1αexpression and reduced the expression of SREBP-1c in Chang liver cells. Our findings suggest that piperine treatment effectively regulates hyperglycemic and hyperinsulinemic insulin resistance in the liver by modulating the expression of HNF-1α and SREBP-1c. Consequently, piperine emerges as a promising candidate for therapeutic intervention in managing T2DM.

Upregulation of hepatic nuclear receptors in extremely preterm ovine fetuses undergoing artificial placenta therapy

Objective Extremely preterm infants have low Nuclear Receptor (NR) expression in their developing hepatobiliary systems, as they rely on the placenta and maternal liver for compensation. NRs play a crucial role in detoxification and the elimination of both endogenous and xenobiotic substances by regulating key genes encoding specific proteins. In this study, we utilized an Artificial Placenta Therapy (APT) platform to examine the liver tissue expression of NRs of extremely preterm ovine fetuses. This fetal model, resembling a “knockout placenta,” lacks placental and maternal support, while maintaining a healthy extrauterine survival. Methods Six ovine fetuses at 95 ± 1 d gestational age (GA; term = ∼150 d)/∼600 g delivery weight were maintained on an APT platform for a period of 120 h (APT Group). Six age-matched, in utero control fetuses were delivered at 99–100 d GA (Control Group). Fetal liver tissue samples and blood samples were collected at delivery from both groups and assessed mRNA expression of NRs and target transporters involved in the hepatobiliary transport system using quantitative PCR. Data were tested for group differences with ANOVA (p < .05 deemed significant). Results mRNA expression of NRs was identified in both the placenta and the extremely preterm ovine fetal liver. The expression of HNF4α, LRH1, LXR, ESR1, PXR, CAR, and PPARα/γ were significantly elevated in the liver of the APT Group compared to the Control Group. Moreover, target transporters NTCP, OATP1B3, BSEP, and MRP4 were upregulated, whereas MRP2 and MRP3 were unchanged. Although there was no evidence of liver necrosis or apoptotic changes histologically, there was an impact in the fetal liver of the ATP group at the tissue level with a significant increase in TNFα mRNA, a cytokine involved in liver inflammation, and blood elevation of transaminases. Conclusion A number of NRs in the fetal liver were significantly upregulated after loss of placental-maternal support. However, the expression of target transporter genes appeared to be insufficient to compensate role of the placenta and maternal liver and avoid fetal liver damage, potentially due to insufficient excretion of organic anions.

Bile duct ligation elevates 5-HT levels in cerebral cortex of rats partly due to impairment of brain UGT1A6 expression and activity via ammonia accumulation

Hepatic encephalopathy (HE) is often associated with endogenous serotonin (5-HT) disorders. However, the reason for elevated brain 5-HT levels due to liver failure remains unclear. This study aimed to investigate the mechanism by which liver failure increases brain 5-HT levels and the role in behavioral abnormalities in HE. Using bile duct ligation (BDL) rats as a HE model, we verified the elevated 5-HT levels in the cortex but not in the hippocampus and striatum, and found that this cortical 5-HT overload may be caused by BDL-mediated inhibition of UDP-glucuronosyltransferase 1A6 (UGT1A6) expression and activity in the cortex. The intraventricular injection of the UGT1A6 inhibitor diclofenac into rats demonstrated that the inhibition of brain UGT1A6 activity significantly increased cerebral 5-HT levels and induced HE-like behaviors. Co-immunofluorescence experiments demonstrated that UGT1A6 is primarily expressed in astrocytes. In vitro studies confirmed that NH4Cl activates the ROS-ERK pathway to downregulate UGT1A6 activity and expression in U251 cells, which can be reversed by the oxidative stress antagonist N-acetyl-l-cysteine and the ERK inhibitor U0126. Silencing Hepatocyte Nuclear Factor 4α (HNF4α) suppressed UGT1A6 expression whilst overexpressing HNF4α increased Ugt1a6 promotor activity. Meanwhile, both NH4Cl and the ERK activator TBHQ downregulated HNF4α and UGT1A6 expression. In the cortex of hyperammonemic rats, we also found activation of the ROS-ERK pathway, decreases in HNF4α and UGT1A6 expression, and increases in brain 5-HT content. These results prove that the ammonia-mediated ROS-ERK pathway activation inhibits HNF4α expression to downregulate UGT1A6 expression and activity, thereby increasing cerebral 5-HT content and inducing manic-like HE symptoms. This is the first study to reveal the mechanism of elevated cortical 5-HT concentration in a state of liver failure and elucidate its association with manic-like behaviors in HE.

Transient Receptor Potential channels (TRP) in GtoPdb v.2023.3

Transient Receptor Potential channels (TRP) in GtoPdb v.2023.3

Mechanism and Effect of HNF4α Decrease in a Rat Model of Cirrhosis and Liver Failure

Background & AimsHNF4α, a master regulator of liver development and the mature hepatocyte phenotype, is downregulated in chronic and inflammatory liver disease. We used contemporary transcriptomics and epigenomics to study the cause and effects of this downregulation, and characterized a multicellular etiology. MethodsProgressive changes in the rat CCl4-model were studied by deep RNA sequencing and genome-wide ChIP-seq analysis of transcription factor (TF) binding and chromatin modification. Studies compared decompensated cirrhosis with liver failure after 26 weeks of treatment to earlier compensated cirrhosis, and to additional rat models of chronic fibrosis. Finally, to resolve cell-specific responses and intercellular signaling, we compared transcriptomes of liver, non-parenchymal, and inflammatory cells. ResultsHNF4α was significantly lower in 26-week cirrhosis, part of a general reduction of TF that regulate metabolism. Nevertheless, increased binding of HNF4α contributed to strong activation of major phenotypic genes, while reduced binding to other genes had a moderate phenotypic effect. Decreased Hnf4a expression was the combined effect of STAT3 and NFκB activation, which similarly reduced expression of other metabolic TF. STAT/NFκB also induced de novo expression of Osmr by hepatocytes, to complement induced expression of Osm by nonparenchymal cells. ConclusionsLiver decompensation by inflammatory STAT3 and NFκB signaling was not a direct consequence of progressive cirrhosis. Despite significant reduction of Hnf4a expression, residual levels of this abundant TF still stimulated strong new gene expression. Reduction of HNF4α was part of a broad hepatocyte transcriptional response to inflammation.

Differential spatial distribution of HNF4α isoforms during dysplastic progression of intraductal papillary mucinous neoplasms of the pancreas

Hepatocyte Nuclear Factor 4-alpha (HNF4α) comprises a nuclear receptor superfamily of ligand-dependent transcription factors that yields twelve isoforms in humans, classified into promoters P1 or P2-associated groups with specific functions. Alterations in HNF4α isoforms have been associated with tumorigenesis. However, the distribution of its isoforms during progression from dysplasia to malignancy has not been studied, nor has it yet been studied in intraductal papillary mucinous neoplasms, where both malignant and pre-malignant forms are routinely clinically identified. We examined the expression patterns of pan-promoter, P1-specific, and P2-specific isoform groups in normal pancreatic components and IPMNs. Pan-promoter, P1 and P2 nuclear expression were weakly positive in normal pancreatic components. Nuclear expression for all isoform groups was increased in low-grade IPMN, high-grade IPMN, and well-differentiated invasive adenocarcinoma. Poorly differentiated invasive components in IPMNs showed loss of all forms of HNF4α. Pan-promoter, and P1-specific HNF4α expression showed shifts in subnuclear and sub-anatomical distribution in IPMN, whereas P2 expression was consistently nuclear. Tumor cells with high-grade dysplasia at the basal interface with the stroma showed reduced expression of P1, while P2 was equally expressed in both components. Additional functional studies are warranted to further explore the mechanisms underlying the spatial and differential distribution of HNF4α isoforms in IPMNs.

Deubiquitinase OTUD5 promotes hepatitis B virus replication by removing K48-linked ubiquitination of HBV core/precore and upregulates HNF4ɑ expressions by inhibiting the ERK1/2/mitogen-activated protein kinase pathway

Hepatitis B virus (HBV) infection is a major public health problem worldwide, causing nearly one million deaths annually. OTUD5 is a deubiquitinase associated with cancer development and innate immunity response. However, the regulatory mechanisms of OTUD5 underlying HBV replication need to be deeply elucidated. In the present investigation, we found that HBV induced significant up-regulation of OTUD5 protein in HBV-infected cells. Further study showed that OTUD5 interacted with HBV core/precore, removing their K48-linked ubiquitination chains and protecting their stability. Meanwhile, overexpression of OTUD5 could inhibit the MAPK pathway and then increase the expression of HNF4ɑ, and ERK1/2 signaling was required for OTUD5-mediated activation of HNF4α, promoting HBV replication. Together, these data indicate that OTUD5 could deubiquitinate HBV core protein degradation by its deubiquitinase function and promote HBV activity by up-regulating HNF4α expression via inhibition of the ERK1/2 pathway. These results might present a novel therapeutic strategy against HBV infection.

HIF1α/miR-146α/TRAF6/NF-κB axis modulates hepatic iron overload-induced inflammation

Transfusional therapy is used to cure anemia but raises the risk of hepatic iron overload (IO), which triggers oxidative stress damage, inflammation, and failure even fibrosis. microRNAs play a vital role in developing hepatic diseases. This study presented the mechanism by which IO induce hepatic inflammation through microRNAs. In this study, microRNA expression profiling in the liver was observed after IO for 2 weeks, in which the target microRNA will be found. IO activating the miR-146α/TRAF6/NF-κB pathway was validated, and the molecular mechanism of the IO-induced decrease of miR-146α in the liver was studied in vivo and in vitro. The expression of TRAF6/NF-κB (p65)-dependent inflammatory factors increased, whereas the expression of miR-146α decreased during the IO-induced inflammatory response in the liver. The reduced expression of HNF4α caused by HIF1α and miR-34α may decrease the expression of miR-146α. Overexpression of miR-146α alleviated the hepatic inflammatory response caused by IO. Our findings indicate that miR-146α is a key factor in inducing hepatic IO inflammation, which will be another potential target to prevent IO-induced hepatic damage.

Dendrobium officinale Polysaccharides Inhibit CDCA-Induced Gastric Intestinal Metaplasia through Activating NRF2/HO-1 and Modulating HNF4α/CDX2 Signaling Pathway

Bile reflux (BR) was considered to be an independent risk factor for the development of precancerous gastric lesions and GC. Dendrobium officinale polysaccharides (DOP) show a novel potential in preventing the progress of gastric cancer. However, the specific mechanism of DOP that causes such activities remains a mystery. This study aimed to investigate the effects of DOP on chenodeoxycholic acid (CDCA)-induced gastric intestinal metaplasia and explore the underlying mechanisms. Different concentrations of DOP had no significant damage to normal GSE-1 cells and gastric intestinal metaplasia model cells by CCK-8 assay. After DOP treatment, the mRNA and protein expression of CDX2 ( p &lt; 0.01) and HNF4α ( p &lt; 0.01) were decreased, and HO-1 ( p &lt; 0.05) and TFF2 ( p &lt; 0.01) were increased. The NRF2 protein expression was slightly upregulated ( p &lt; 0.05), and H-DOP further promoted NRF2 protein expression in the nucleus ( p &lt; 0.05). Hence, our findings reveal that DOP could be used as a potential anti-inflammation supplement by activating NRF2/HO-1 and modulating the HNF4α/CDX2 signaling pathway to inhibit the progress of CDCA-induced gastric intestinal metaplasia.

Insulin Determines Transforming Growth Factor β Effects on Hepatocyte Nuclear Factor 4α Transcription in Hepatocytes

Loss of hepatocyte nuclear factor 4α (HNF4α) expression is frequently observed in end-stage liver disease and associated with loss of vital liver functions, thus increasing mortality. Loss of HNF4α expression is mediated by inflammatory cytokines, such as transforming growth factor (TGF)-β. However, details of how HNF4α is suppressed are largely unknown to date. Herein, TGF-β did not directly inhibit HNF4α but contributed to its transcriptional regulation by SMAD2/3 recruiting acetyltransferase CREB-binding protein/p300 to the HNF4α promoter. The recruitment of CREB-binding protein/p300 is indispensable for CCAAT/enhancer-binding protein α (C/EBPα) binding, another essential requirement for constitutive HNF4α expression in hepatocytes. Consistent with the invitro observation, 67 of 98 patients with hepatic HNF4α expressed both phospho-SMAD2 and C/EBPα, whereas 22 patients without HNF4α expression lacked either phospho-SMAD2 or C/EBPα. In contrast to the observed induction of HNF4α, SMAD2/3 inhibited C/EBPα transcription. Long-term TGF-β incubation resulted in C/EBPα depletion, which abrogated HNF4α expression. Intriguingly, SMAD2/3 inhibitory binding to the C/EBPα promoter was abolished by insulin. Two-thirds of patients without C/EBPα lacked membrane glucose transporter type 2 expression in hepatocytes, indicating insulin resistance. Taken together, these data indicate that hepatic insulin sensitivity is essential for hepatic HNF4α expression in the condition of inflammation.

Protective roles of adiponectin and molecular signatures of HNF4α and PPARα as downstream targets of adiponectin in pancreatic β cells

The disease progression of the metabolic syndrome is associated with prolonged hyperlipidemia and insulin resistance, eventually giving rise to impaired insulin secretion, often concomitant with hypoadiponectinemia. As an adipose tissue derived hormone, adiponectin is beneficial for insulin secretion and β cell health and differentiation. However, the down-stream pathway of adiponectin in the pancreatic islets has not been studied extensively. Here, along with the overall reduction of endocrine pancreatic function in islets from adiponectin KO mice, we examine PPARα and HNF4α as additional down-regulated transcription factors during a prolonged metabolic challenge. To elucidate the function of β cell-specific PPARα and HNF4α expression, we developed doxycycline inducible pancreatic β cell-specific PPARα (β-PPARα) and HNF4α (β-HNF4α) overexpression mice. β-PPARα mice exhibited improved protection from lipotoxicity, but elevated β-oxidative damage in the islets, and also displayed lowered phospholipid levels and impaired glucose-stimulated insulin secretion. β-HNF4α mice showed a more severe phenotype when compared to β-PPARα mice, characterized by lower body weight, small islet mass and impaired insulin secretion. RNA-sequencing of the islets of these models highlights overlapping yet unique roles of β-PPARα and β-HNF4α. Given that β-HNF4α potently induces PPARα expression, we define a novel adiponectin-HNF4α-PPARα cascade. We further analyzed downstream genes consistently regulated by this axis. Among them, the islet amyloid polypeptide (IAPP) gene is an important target and accumulates in adiponectin KO mice. We propose a new mechanism of IAPP aggregation in type 2 diabetes through reduced adiponectin action.

The Effects of Retinoic Acid on the Expression of HNF4α and Cdx-2 Genes in Caco-2 Cells as a Model of Intestinal Barrier

The Effects of Retinoic Acid on the Expression of HNF4α and Cdx-2 Genes in Caco-2 Cells as a Model of Intestinal Barrier

Sex-specific effects of acute chlordane exposure in the context of steatotic liver disease, energy metabolism and endocrine disruption.

Chlordane is an organochlorine pesticide (OCP) that is environmentally persistent. Although exposures to OCPs including chlordane have been associated with elevated liver enzymes, current knowledge on OCPs' contribution to toxicant-associated steatotic liver disease (TASLD) and underlying sex-specific metabolic/endocrine disruption are still widely limited. Therefore, the objective of this study was to investigate the sex-dependent effects of chlordane in the context of TASLD. Age-matched male and female C57BL/6 mice were exposed to chlordane (20mg/kg, one-time oral gavage) for two weeks. Female mice generally exhibited lower bodyfat content but more steatosis and hepatic lipid levels, consistent with increased hepatic mRNA levels of genes involved in lipid synthesis and uptake. Surprisingly, chlordane-exposed females demonstrated lower hepatic cholesterol levels. With regards to metabolic disruption, chlordane exposure decreased expression of genes involved in glycogen and glucose metabolism (Pklr, Gck), while chlordane-exposed females also exhibited decreased gene expression of HNF4A, an important regulator of liver identity and function. In terms of endocrine endpoints, chlordane augmented plasma testosterone levels in males. Furthermore, chlordane activated hepatic xenobiotic receptors, including the constitutive androstane receptor, in a sex-dependent manner. Overall, chlordane exposure led to altered hepatic energy metabolism, and potential chlordane-sex interactions regulated metabolic/endocrine disruption and receptor activation outcomes.

Mutations on a conserved distal enhancer in the porcine C-reactive protein gene impair its expression in liver.

C-reactive protein (CRP) is an evolutionary highly conserved protein. Like humans, CRP acts as a major acute phase protein in pigs. While CRP regulatory mechanisms have been extensively studied in humans, little is known about the molecular mechanisms that control pig CRP gene expression. The main goal of the present work was to study the regulatory mechanisms and identify functional genetic variants regulating CRP gene expression and CRP blood levels in pigs. The characterization of the porcine CRP proximal promoter region revealed a high level of conservation with both cow and human promoters, sharing binding sites for transcription factors required for CRP expression. Through genome-wide association studies and fine mapping, the most associated variants with both mRNA and protein CRP levels were localized in a genomic region 39.3 kb upstream of CRP. Further study of the region revealed a highly conserved putative enhancer that contains binding sites for several transcriptional regulators such as STAT3, NF-kB or C/EBP-β. Luciferase reporter assays showed the necessity of this enhancer-promoter interaction for the acute phase induction of CRP expression in liver, where differences in the enhancer sequences significantly modified CRP activity. The associated polymorphisms disrupted the putative binding sites for HNF4α and FOXA2 transcription factors. The high correlation between HNF4α and CRP expression levels suggest the participation of HNF4α in the regulatory mechanism of porcine CRP expression through the modification of its binding site in liver. Our findings determine, for the first time, the relevance of a distal regulatory element essential for the acute phase induction of porcine CRP in liver and identify functional polymorphisms that can be included in pig breeding programs to improve immunocompetence.

Single cell multiomic analysis reveals diabetes-associated β-cell heterogeneity driven by HNF1A

Broad heterogeneity in pancreatic β-cell function and morphology has been widely reported. However, determining which components of this cellular heterogeneity serve a diabetes-relevant function remains challenging. Here, we integrate single-cell transcriptome, single-nuclei chromatin accessibility, and cell-type specific 3D genome profiles from human islets and identify Type II Diabetes (T2D)-associated β-cell heterogeneity at both transcriptomic and epigenomic levels. We develop a computational method to explicitly dissect the intra-donor and inter-donor heterogeneity between single β-cells, which reflect distinct mechanisms of T2D pathogenesis. Integrative transcriptomic and epigenomic analysis identifies HNF1A as a principal driver of intra-donor heterogeneity between β-cells from the same donors; HNF1A expression is also reduced in β-cells from T2D donors. Interestingly, HNF1A activity in single β-cells is significantly associated with lower Na+ currents and we nominate a HNF1A target, FXYD2, as the primary mitigator. Our study demonstrates the value of investigating disease-associated single-cell heterogeneity and provides new insights into the pathogenesis of T2D.

Red and golden tomato administration improves fat diet-induced hepatic steatosis in rats by modulating HNF4α, Lepr, and GK expression.

Nonalcoholic fatty liver disease (NAFLD), characterized by lipid accumulation within hepatocytes exceeding 5% of liver weight, is strongly related to metabolic disorders, obesity, and diabetes and represents a health emergency worldwide. There is no standard therapy available for NAFLD. Lifestyle intervention, including phytonutrient intake, is key in preventing NAFLD development and progression. We used a rat model of NAFLD to evaluate the effect of dietary supplementation with red tomato (RT) and golden tomato (GT)-a patented mix of fruit with varying degrees of ripeness and particularly rich in naringenin and chlorogenic acid-after steatosis development. We assessed the effects on body weight, metabolic profile, and hepatic steatosis. We found a correlation between the amelioration of all the parameters and the liver gene expression. Our results showed that, together with the reversion of steatosis, the consumption of RT and GT can cause a significant reduction in triglycerides, low-density lipoprotein-cholesterol, fasting glucose, and homeostasis model assessment index. Meanwhile, we observed an increase in high-density lipoprotein-cholesterol according to the amelioration of the general lipidic profile. Regarding hepatic gene expression, we found the upregulation of Gk and Hnf4α involved in metabolic homeostasis, Lepr involved in adipokine signaling, and Il6 and Tnf involved in inflammatory response. Taken together, our results suggest that dietary intake of red and golden tomatoes, as a nutraceutical approach, has potential in preventing and therapeutics of NAFLD.

Ectopic expression of HNF4α in Het1A cells induces an invasive phenotype

Barrett's oesophagus (BO) is a pathological condition in which the squamous epithelium of the distal oesophagus is replaced by an intestinal-like columnar epithelium originating from the gastric cardia. Several somatic mutations contribute to the intestinal-like metaplasia. Once these have occurred in a single cell, it will be unable to expand further unless the altered cell can colonise the surrounding squamous epithelium of the oesophagus. The mechanisms by which this happens are still unknown. Here we have established an in vitro system for examining the competitive behaviour of two epithelia. We find that when an oesophageal epithelium model (Het1A cells) is confronted by an intestinal epithelium model (Caco-2 cells), the intestinal cells expand into the oesophageal domain. In this case the boundary involves overgrowth by the Caco-2 cells and the formation of isolated colonies. Two key transcription factors, normally involved in intestinal development, HNF4α and CDX2, are both expressed in BO. We examined the competitive ability of Het1A cells stably expressing HNF4α or CDX2 and placed in confrontation with unmodified Het1A cells. The key result is that stable expression of HNF4α, but not CDX2, increased the ability of the cells to migrate and push into the unmodified Het1A domain. In this situation the boundary between the cell types is a sharp one, as is normally seen in BO. The experiments were conducted using a variety of extracellular substrates, which all tended to increase the cell migration compared to uncoated plastic. These data provide evidence that HNF4α expression could have a potential role in the competitive spread of BO into the oesophagus as HNF4α increases the ability of cells to invade into the adjacent stratified squamous epithelium, thus enabling a single mutant cell eventually to generate a macroscopic patch of metaplasia.

Bergamot (Citrus bergamia) peel extract as new hypocholesterolemic agent modulating PCSK9 expression

Citrus bergamia extracts have been studied for the management of hypercholesterolemia disorders. Up to now limited information is available concerning the activity of its main phytoconstituents towards the main targets of the cholesterol homeostasis. In the present study, the effects of bergamot peel extract and isolated constituents, namely glycosidic and non-glycosidic flavonoids, one coumarin and one limonoid on the low-density lipoprotein receptor (LDLR) and proprotein convertase subtilisin/kexin type 9 (PCSK9) were evaluated by using cultured HuH7 cell line. Furthermore, for the first time the effects of bergamot peel extract were studied to describe a potential hypolipidemic action. Significant differences were observed due to glycosylation and different substitution on flavanone moiety (O-methylation). Considering the thirteen isolated compounds, both naringenin-7-O-rutinoside (NA-rut) and apigenin-6,8-C-glicoside induced the expression of the LDLR while no effect was observed on PCSK9. However, hesperetin (HE) and its derivatives, hesperetin-7-O-glucoside and hesperetin-7-O-neohesperidoside (HE-glu, HE-neo) and eriodictyol (ER) showed a statin-like effect since a significant increase of both LDLR and PCSK9 expression were detected. Furthermore, bergamot peel extract (BE) firstly demonstrated a significant reduction of PCSK9 expression, indicating a potential adjuvant action to statins. BE, HE-neo, and NA-rut reduced intracellular sterols and the expression of PCSK9 transcription factor HNF1-α. BE also significantly improved the LDL uptake u Huh7 cells. Based on the present data, bergamot peel constituents can play a role in the management of hypercholesterolemia, on one hand they may produce an adjuvant action in combination with statins, while on the other hand they may have a statin-like effect. Additionally, BE may be a good candidate as an adjuvant to statins action.

Transient Receptor Potential channels (TRP) in GtoPdb v.2023.2

Transient Receptor Potential channels (TRP) in GtoPdb v.2023.2