scholarly journals Hepatic Polarization Accelerated by Mechanical Compaction Involves HNF4α Activation

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Jinlian Yang ◽  
Jiaen Liang ◽  
Yongjian Zheng ◽  
Shiying Li ◽  
Yang Li ◽  
...  
Keyword(s):  
Cell Model ◽  
Mrna Level ◽  
Hepatocyte Nuclear Factor ◽  
Primary Hepatocytes ◽  
Mechanical Compaction ◽  
Hepatocyte Nuclear Factor 4 ◽  
Compaction Force ◽  
Mechanical Transduction ◽  
Few Data

There remain few data about the role of homeostatic compaction in hepatic polarization. A previous study has found that mechanical compaction can accelerate hepatocyte polarization; however, the cellular mechanism underlying the effect is mostly unclear. Hepatocyte nuclear factor 4 alpha (HNF4α) is crucial for hepatic polarization in liver morphogenesis. Therefore, we sought to identify any possible involvement of HNF4α in the process of hepatocyte polarization accelerated by mechanical compaction. We first verified in the nonhepatic cell model HEK-293T, and the hepatic cell model primary hepatocytes that the mechanical compaction on cell aggregates simulated by using transient centrifugation can directly activate the expression of HNF4α promoters. Moreover, data using primary hepatocytes showed that the HNF4α expression is positively associated with the levels of compaction force: 2.1-folds higher at the mRNA level and 2.1-folds higher at the protein level for 500 g vs. 0 g. Furthermore, activated HNF4α expression is associated with the enhanced biliary canalicular formation and the increased production of albumin and urea. Pretreatment with Latrunculin B, an inhibitor of F-actin, and SHE78-7, an inhibitor of E-cadherin, which both interrupt the pathway of mechanical transduction, partially but significantly reduced the HNF4α expression and production of albumin and urea. In conclusion, HNF4α can be actively involved in the hepatic polarization in the context of environmental mechanical compaction.

scholarly journals LncRNA MEG3 influences the proliferation and apoptosis of psoriasis epidermal cells by targeting miR-21/caspase-8

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Hai-Yan Jia ◽  
Kai Zhang ◽  
Wen-Jing Lu ◽  
Gui-Wen Xu ◽  
Jian-Fen Zhang ◽  
...  
Keyword(s):  
Binding Site ◽  
Cell Model ◽  
Mrna Level ◽  
Epidermal Cells ◽  
Luciferase Reporter ◽  
Psoriatic Skin ◽  
Caspase 8 ◽  
Proliferation And Apoptosis

Abstract Background It was reported that microRNA-21(miR-21) was differentially expressed in the keratinocytes of psoriasis patients, and it may influence the apoptosis and proliferation of cells. The role of lncRNA maternally expressed gene3 (MEG3), a competing endogenous RNAs of miR-21, in the progression of psoriasis remains unclear. We aimed to unfold the influence of MEG3 and miR-21 on the proliferation and apoptosis of psoriasis epidermal cells. Methods 50μg/L TNF-α was used to treat HaCaTs and NHEKs cells for 24 h, and then different experiments were conducted. qRT-PCR were applied for measuring the mRNA level of MEG3, miR-2, and caspase-8, and the protein expression of caspase-8 was measured with western blotting. Flow cytometry was used for assessing apoptosis. Cell proliferation was detected using MTT and colony formation assays. Dual luciferase reporter assay was applied for confirming the binding site between MEG3 and miR-21, miR-21 and Caspase-8. Results A cell model for in vitro studying the role of MEG3 in psoriasis pathophysiology was established using HaCaT and HHEKs. MEG3 was significantly down-regulated in HaCaT, HHEKs, and psoriatic skin samples. MEG3 inhibits proliferation and promotes apoptosis of Activated-HaCaT (Act-HaCaT) and Activated-HHEKs (Act- HHEK) by regulating miR-21, and the binding site between MEG3 and miR-21 was identified. We also found that miR-21 could inhibit the level of caspase-8 and identified the binding site between caspase-8 and miR-21. Some down-stream proteins of caspase-8, Cleaved caspase-8, cytc, and apaf-1 were regulated by miR-21 and MEG3. Conclusion MEG3/miR-21 axis may regulate the expression of caspase-8, and further influence the proliferation and apoptosis of psoriasis keratinocyte, Act-HaCaT and Act- HHEK. Therefore, our findings may provide a new thought for the study of pathogenesis and treatment of psoriasis.

scholarly journals Regulation of Cyp2a5 transcription in mouse primary hepatocytes: roles of hepatocyte nuclear factor 4 and nuclear factor I

2004 ◽  
Vol 381 (3) ◽  
pp. 887-894 ◽  
Author(s):  
Johanna ULVILA ◽  
Satu ARPIAINEN ◽  
Olavi PELKONEN ◽  
Kaoru AIDA ◽  
Tatsuya SUEYOSHI ◽  
...  
Keyword(s):  
Binding Site ◽  
Proximal Promoter ◽  
Luciferase Reporter ◽  
Nuclear Factor ◽  
Hepatocyte Nuclear Factor ◽  
Primary Hepatocytes ◽  
Double Mutation ◽  
Factor I ◽  
Nuclear Factor I ◽  
Hepatocyte Nuclear Factor 4

The cytochrome P4502a5 (Cyp2a5) gene is expressed principally in liver and olfactory mucosa. In the present study, the transcriptional mechanisms of hepatocyte-specific expression of Cyp2a5 were studied in mouse primary hepatocytes. The Cyp2a5 5′-flanking region −3033 to +10 was cloned in front of a luciferase reporter gene and transfected into hepatocytes. Deletion analysis revealed two major activating promoter regions localized at proximal 271 bp and at a more distal area from −3033 to −2014 bp. The proximal activation region was characterized further by DNase I footprinting, and a single clear footprint was detected in the studied area centred over a sequence similar to the NF-I (nuclear factor I)-binding site. The binding of NF-I was confirmed using an EMSA (electrophoretic mobility-shift assay). A putative HNF-4 (hepatocyte nuclear factor 4)-binding site was localized at the proximal promoter by computer analysis of the sequence, and HNF-4α was shown to interact with the site using an EMSA. The functional significance of HNF-4 and NF-I binding to the Cyp2a5 promoter was evaluated by site-directed mutagenesis of the binding motifs in reporter constructs. Both mutations strongly decreased transcriptional activation by the Cyp2a5 promoter in primary hepatocytes, and double mutation almost completely abolished transcriptional activity. Also, the functionality of the distal activation region was found to be dependent on the intact HNF-4 and NF-I sites at the proximal promoter. In conclusion, these results indicate that HNF-4 and NF-I play major roles in the constitutive regulation of hepatic expression of Cyp2a5.

scholarly journals Hepatocyte Nuclear Factor 4 alpha (HNF4α) Activation is Essential for Termination of Liver Regeneration

2018 ◽  
Author(s):  
Ian Huck ◽  
Sumedha Gunewardena ◽  
Regina Espanol-Suner ◽  
Holger Willenbring ◽  
Udayan Apte
Keyword(s):  
Gene Expression ◽  
Liver Regeneration ◽  
Target Gene ◽  
Nuclear Factor ◽  
Hepatocyte Nuclear Factor ◽  
Hepatic Differentiation ◽  
Target Gene Expression ◽  
Protein Levels ◽  
Hepatocyte Nuclear Factor 4

AbstractHepatocyte Nuclear Factor 4 alpha (HNF4α) is critical for hepatic differentiation. Recent studies have highlighted its role in inhibition of hepatocyte proliferation and tumor suppression. However, the role of HNF4α in liver regeneration is not known. We hypothesized that hepatocytes modulate HNF4α activity when navigating between differentiated and proliferative states during liver regeneration. Western blot analysis revealed a rapid decline in nuclear and cytoplasmic HNF4α protein levels accompanied with decreased target gene expression within 1 hour after 2/3 partial hepatectomy (post-PH) in C57BL/6J mice. HNF4α protein expression did not recover to the pre-PH levels until day 3. Hepatocyte-specific deletion of HNF4α (HNF4α-KO) in mice resulted in 100% mortality post-PH despite increased proliferative marker expression throughout regeneration. Sustained loss of HNF4α target gene expression throughout regeneration indicated HNF4α-KO mice were unable to compensate for loss of HNF4α transcriptional activity. Deletion of HNF4α resulted in sustained proliferation accompanied by c-myc and cyclin D1 over expression and a complete deficiency of hepatocyte function after PH. Interestingly, overexpression of degradation-resistant HNF4α in hepatocytes did not prevent initiation of regeneration after PH. Finally, AAV8-mediated reexpression of HNF4α in hepatocytes of HNF4α-KO mice post-PH restored HNF4α protein levels, induced target gene expression and improved survival of HNF4α-KO mice post-PH. In conclusion, these data indicate that HNF4α reexpression following initial decrease is critical for hepatocytes to exit from cell cycle and resume function during the termination phase of liver regeneration. These results reveal the role of HNF4α in liver regeneration and have implications for therapy of liver failure.

scholarly journals Hepatocyte Nuclear Factor 4 Alpha Attenuated Lipotoxicity, But Increased Bile Acid Toxicity in Non-Alcoholic Fatty Liver Disease Model.

2021 ◽  
Author(s):  
Yun Jin Noh ◽  
Jae Sun Lee ◽  
Dae Won Jun ◽  
Sung Ryol Lee ◽  
Ju Hee Oh ◽  
...  
Keyword(s):  
Bile Acid ◽  
Nuclear Factor ◽  
Hepatocyte Nuclear Factor ◽  
Alcoholic Fatty Liver ◽  
Hepatic Fat ◽  
Hepatocyte Nuclear Factor 4 ◽  
Acid Toxicity ◽  
Nafld Activity Score ◽  
Alcoholic Fatty Liver Disease

Abstract Background: It is known that hepatocyte nuclear factor 4 alpha (HNF4α) is key master nuclear receptor for hepatic fat and bile acid metabolic pathways. But the role of HNF4α in non-alcoholic fatty liver disease (NAFLD) is complex. The current study aimed to investigate role of HNF4α in NAFLD. Methods: Hepatic HNF4α expression evaluated in human NAFLD subjects. Free fatty acid induced lipotoxicity evaluated under HNF4α over- and down regulation. Chenodeoxy cholic acid (CDCA) induced bile acid toxicity evaluated under HNF4α in In Vitro NAFLD model. NAFLD activity score and fibrosis assessed after HNF4α silencing in methionine choline deficiency diet fed mice. Results: Hepatic HNF4α expression was higher in NAFLD than in control group. Overexpression of HNF4α reduced intracellular lipid contents via increasing mitochondria beta-oxidation and hepatic fat excretion. HNF4α overexpression attenuated palmitic acid (PA) induced lipotoxicity. Protective effects of HNF4α on cell death were reversed when CDCA co-treated with PA. CDCA mono-treatment did not affect cell viability, but co-treatment with PA and CDCA decreased cell viability. Bile acid toxicity of HNF4α was exaggerated under PA co-treatment with CDCA. HNF4α knock down using small interfering RNA recovered cell apoptosis and increased cell proliferation from PA and CDCA co-treatment condition. Inhibition of HNF4α using sh-HNF4α adenovirus vector did not reduce hepatic fat accumulation, but decreased intrahepatic inflammation and NAFLD activity score compared to control.Conclusions: HNF4α increased free fatty acid oxidation and attenuated lipotixicity, but increased bile acid toxicity in NAFLD animal model. Inhibition of HNF4α attenuated In vivo NAFLD model.

scholarly journals Increased expression of hepatocyte nuclear factor 4 alpha transcribed by promoter 2 indicates a poor prognosis in hepatocellular carcinoma

2017 ◽  
Vol 10 (10) ◽  
pp. 761-771 ◽  
Author(s):  
Shao-hang Cai ◽  
Shi-xun Lu ◽  
Li-li Liu ◽  
Chris Zhiyi Zhang ◽  
Jing-ping Yun
Keyword(s):  
Hepatocellular Carcinoma ◽  
Training Group ◽  
Tissue Microarrays ◽  
Favourable Outcome ◽  
Nuclear Factor ◽  
Hepatocyte Nuclear Factor ◽  
Kaplan Meier ◽  
Hepatocyte Nuclear Factor 4 ◽  
Prognostic Prediction

Background: Hepatocyte nuclear factor 4 alpha (HNF4α) plays an important role in tumourigenesis. There is growing evidence indicating that HNF4α transcribed by promoter 1 (P1-HNF4α) is expressed at relatively low levels in HCC and its presence predicts a favourable outcome for hepatocellular carcinoma (HCC) patients. However, the role of HNF4α transcribed by promoter 2 (P2-HNF4α) in HCC remains unclear. Methods: A total of 615 HCC specimens were obtained to construct tissue microarrays and perform immunohistochemistry. The relationship between P2-HNF4α and clinical features of HCC patients were analysed. Kaplan–Meier analysis was conducted to assess the prognostic value of P2-HNF4α. Results: The results showed that the expression of P2-HNF4α in HCC was noticeably increased in HCC tissues compared with the nontumourous tissues. In addition, P1-HNF4α expression was negatively correlated with P2-HNF4α expression ( p = 0.023). High P2-HNF4α expression was significantly associated with poor differentiation of HCC ( p = 0.002) and vascular invasion ( p = 0.017). Kaplan–Meier analysis showed that P2-HNF4α expression was closely correlated with overall survival in the training group ( p = 0.01), validation group ( p = 0.034), and overall group of patients with HCC ( p < 0.001). Conclusions: Our data show that the role of HNF4α in cancer development needs to be further refined. P2-HNF4α, different from P1-HNF4α, is markedly upregulated and serves as an oncogene-associated protein in HCC. Our study therefore provides a promising biomarker for prognostic prediction and a potential therapeutic target for HCC.

scholarly journals Serum transferrin as a biomarker of hepatocyte nuclear factor 4 alpha activity and hepatocyte function in liver diseases

BMC Medicine ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Nurdan Guldiken ◽  
Josepmaria Argemi ◽  
Berivan Gurbuz ◽  
Stephen R. Atkinson ◽  
Martin Oliverius ◽  
...  
Keyword(s):  
Liver Disease ◽  
Liver Failure ◽  
Regulatory Region ◽  
Serum Transferrin ◽  
Mrna Levels ◽  
Nuclear Factor ◽  
Hepatocyte Nuclear Factor ◽  
Primary Hepatocytes ◽  
Advanced Liver Disease ◽  
Hepatocyte Nuclear Factor 4

Abstract Background Serum transferrin levels represent an independent predictor of mortality in patients with liver failure. Hepatocyte nuclear factor 4 alpha (HNF4α) is a master regulator of hepatocyte functions. The aim of this study was to explore whether serum transferrin reflects HNF4α activity. Methods Factors regulating transferrin expression in alcoholic hepatitis (AH) were assessed via transcriptomic/methylomic analysis as well as chromatin immunoprecipitation coupled to DNA sequencing. The findings were corroborated in primary hepatocytes. Serum and liver samples from 40 patients with advanced liver disease of multiple etiologies were also studied. Results In patients with advanced liver disease, serum transferrin levels correlated with hepatic transferrin expression (r = 0.51, p = 0.01). Immunohistochemical and biochemical tests confirmed reduced HNF4α and transferrin protein levels in individuals with cirrhosis. In AH, hepatic gene-gene correlation analysis in liver transcriptome revealed an enrichment of HNF4α signature in transferrin-correlated transcriptome while transforming growth factor beta 1 (TGFβ1), tumor necrosis factor α (TNFα), interleukin 1 beta (IL-1β), and interleukin 6 (IL-6) negatively associated with transferrin signature. A key regulatory region in transferrin promoter was hypermethylated in patients with AH. In primary hepatocytes, treatment with TGFβ1 or the HNF4α inhibitor BI6015 suppressed transferrin production, while exposure to TNFα, IL-1β, and IL-6 had no effect. The correlation between hepatic HNF4A and transferrin mRNA levels was also seen in advanced liver disease. Conclusions Serum transferrin levels constitute a prognostic and mechanistic biomarker. Consequently, they may serve as a surrogate of impaired hepatic HNF4α signaling and liver failure.

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