1
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Mao Z, Zhao J, Cui F, Li Z, Cao J, Zhou J, Hou M, Qian Z. STUB1 increases adiponectin expression by inducing ubiquitination and degradation of NR2F2, thereby reducing hepatic stellate cell activation and alleviating non-alcoholic fatty liver disease. Tissue Cell 2024; 88:102345. [PMID: 38471267 DOI: 10.1016/j.tice.2024.102345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Revised: 02/28/2024] [Accepted: 02/29/2024] [Indexed: 03/14/2024]
Abstract
BACKGROUND Adiponectin (APN) has exhibited ameliorating effects on non-alcoholic fatty liver disease (NAFLD). This study investigates the roles of APN and its regulatory molecules in hepatic stellate cell (HSC) activation and the progression of NAFLD. METHODS Mice were subjected to a high-fat diet (HFD) to establish NAFLD models. Liver tissue was examined for lipid metabolism, fibrosis, and inflammation. Mouse 3T3-L1 adipocytes were exposed to palmitic acid (PA) to mimic a high-fat environment. The conditioned medium (CM) from adipocytes was collected for the culture of isolated mouse HSCs. Gain- or loss-of-function studies of APN, nuclear receptor subfamily 2 group F member 2 (NR2F2), and STIP1 homology and U-box containing protein 1 (STUB1) were performed to analyze their roles in NAFLD and HSC activation in vivo and in vitro. RESULTS APN expression was poorly expressed in HFD-fed mice and PA-treated 3T3-L1 adipocytes, which was attributed to the transcription inhibition mediated by NR2F2. Silencing of NR2F2 restored the APN expression, ameliorating liver steatosis, fibrosis, and inflammatory cytokine infiltration in mouse livers and reducing HSC activation. Similarly, the NR2F2 silencing condition reduced HSC activation in vitro. However, these effects were counteracted by artificial APN silencing. STUB1 facilitated the ubiquitination and protein degradation of NR2F2, and its upregulation mitigated NAFLD-like symptoms in mice and HSC activation, effects reversed by the NR2F2 overexpression. CONCLUSION This study highlights the role of STUB1 in reducing HSC activation and alleviating NAFLD by attenuating NR2F2-mediated transcriptional repression of APN.
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Affiliation(s)
- Zheng Mao
- Department of Clinical Laboratory, Wuhu Hospital Affiliated to Anhui University of Science and Technology (The First People's Hospital of Wuhu), Wuhu, Anhui 241000, PR China
| | - Jindong Zhao
- Department of Endocrinology, The First Affiliated Hospital of Anhui University of Chinese Medicine, Hefei, Anhui 230038, PR China
| | - Fan Cui
- Department of Clinical Laboratory, Wuhu Hospital Affiliated to Anhui University of Science and Technology (The First People's Hospital of Wuhu), Wuhu, Anhui 241000, PR China
| | - Zhen Li
- Department of Clinical Laboratory, Wuhu Hospital Affiliated to Anhui University of Science and Technology (The First People's Hospital of Wuhu), Wuhu, Anhui 241000, PR China
| | - Jinjin Cao
- Department of Clinical Laboratory, Wuhu Hospital Affiliated to Anhui University of Science and Technology (The First People's Hospital of Wuhu), Wuhu, Anhui 241000, PR China
| | - Jingjing Zhou
- Department of Clinical Laboratory, Wuhu Hospital Affiliated to Anhui University of Science and Technology (The First People's Hospital of Wuhu), Wuhu, Anhui 241000, PR China
| | - Mingliang Hou
- Department of Clinical Laboratory, Wuhu Hospital Affiliated to Anhui University of Science and Technology (The First People's Hospital of Wuhu), Wuhu, Anhui 241000, PR China
| | - Zengkun Qian
- Department of Clinical Laboratory, Wuhu Hospital Affiliated to Anhui University of Science and Technology (The First People's Hospital of Wuhu), Wuhu, Anhui 241000, PR China.
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2
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Bendixen SM, Jakobsgaard PR, Hansen D, Hejn KH, Terkelsen MK, Bjerre FA, Thulesen AP, Eriksen NG, Hallenborg P, Geng Y, Dam TV, Larsen FT, Wernberg CW, Vijayathurai J, Scott EAH, Marcher AB, Detlefsen S, Grøntved L, Dimke H, Berdeaux R, de Aguiar Vallim TQ, Olinga P, Lauridsen MM, Krag A, Blagoev B, Ravnskjaer K. Single cell-resolved study of advanced murine MASH reveals a homeostatic pericyte signaling module. J Hepatol 2024; 80:467-481. [PMID: 37972658 DOI: 10.1016/j.jhep.2023.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 10/06/2023] [Accepted: 11/07/2023] [Indexed: 11/19/2023]
Abstract
BACKGROUND & AIMS Metabolic dysfunction-associated steatohepatitis (MASH) is linked to insulin resistance and type 2 diabetes and marked by hepatic inflammation, microvascular dysfunction, and fibrosis, impairing liver function and aggravating metabolic derangements. The liver homeostatic interactions disrupted in MASH are still poorly understood. We aimed to elucidate the plasticity and changing interactions of non-parenchymal cells associated with advanced MASH. METHODS We characterized a diet-induced mouse model of advanced MASH at single-cell resolution and validated findings by assaying chromatin accessibility, bioimaging murine and human livers, and via functional experiments in vivo and in vitro. RESULTS The fibrogenic activation of hepatic stellate cells (HSCs) led to deterioration of a signaling module consisting of the bile acid receptor NR1H4/FXR and HSC-specific GS-protein-coupled receptors (GSPCRs) capable of preserving stellate cell quiescence. Accompanying HSC activation, we further observed the attenuation of HSC Gdf2 expression, and a MASH-associated expansion of a CD207-positive macrophage population likely derived from both incoming monocytes and Kupffer cells. CONCLUSION We conclude that HSC-expressed NR1H4 and GSPCRs of the healthy liver integrate postprandial cues, which sustain HSC quiescence and, through paracrine signals, overall sinusoidal health. Hence HSC activation in MASH not only drives fibrogenesis but may desensitize the hepatic sinusoid to liver homeostatic signals. IMPACT AND IMPLICATIONS Homeostatic interactions between hepatic cell types and their deterioration in metabolic dysfunction-associated steatohepatitis are poorly characterized. In our current single cell-resolved study of advanced murine metabolic dysfunction-associated steatohepatitis, we identified a quiescence-associated hepatic stellate cell-signaling module with potential to preserve normal sinusoid function. As expression levels of its constituents are conserved in the human liver, stimulation of the identified signaling module is a promising therapeutic strategy to restore sinusoid function in chronic liver disease.
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Affiliation(s)
- Sofie M Bendixen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Denmark; Center for Functional Genomics and Tissue Plasticity, University of Southern Denmark, Denmark
| | - Peter R Jakobsgaard
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Denmark; Center for Functional Genomics and Tissue Plasticity, University of Southern Denmark, Denmark
| | - Daniel Hansen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Denmark; Center for Functional Genomics and Tissue Plasticity, University of Southern Denmark, Denmark
| | - Kamilla H Hejn
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Denmark; Center for Functional Genomics and Tissue Plasticity, University of Southern Denmark, Denmark
| | - Mike K Terkelsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Denmark; Center for Functional Genomics and Tissue Plasticity, University of Southern Denmark, Denmark
| | - Frederik A Bjerre
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Denmark; Center for Functional Genomics and Tissue Plasticity, University of Southern Denmark, Denmark
| | - Annemette P Thulesen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Denmark; Center for Functional Genomics and Tissue Plasticity, University of Southern Denmark, Denmark
| | - Niels G Eriksen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Denmark; Center for Functional Genomics and Tissue Plasticity, University of Southern Denmark, Denmark
| | - Philip Hallenborg
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Denmark; Center for Functional Genomics and Tissue Plasticity, University of Southern Denmark, Denmark
| | - Yana Geng
- Department of Pharmaceutical Technology and Biopharmacy, University of Groningen, the Netherlands
| | - Trine V Dam
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Denmark; Center for Functional Genomics and Tissue Plasticity, University of Southern Denmark, Denmark
| | - Frederik T Larsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Denmark; Center for Functional Genomics and Tissue Plasticity, University of Southern Denmark, Denmark
| | - Charlotte W Wernberg
- Department of Gastroenterology and Hepatology, Odense University Hospital, Denmark; Department of Gastroenterology and Hepatology, University Hospital of South Denmark Esbjerg, Denmark; Center for Functional Genomics and Tissue Plasticity, University of Southern Denmark, Denmark
| | - Janusa Vijayathurai
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Denmark; Center for Functional Genomics and Tissue Plasticity, University of Southern Denmark, Denmark
| | - Emma A H Scott
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Denmark; Center for Functional Genomics and Tissue Plasticity, University of Southern Denmark, Denmark
| | - Ann-Britt Marcher
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Denmark; Center for Functional Genomics and Tissue Plasticity, University of Southern Denmark, Denmark
| | - Sönke Detlefsen
- Department of Pathology, Odense University Hospital, Denmark; Department of Clinical Research, University of Southern Denmark, Denmark
| | - Lars Grøntved
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Denmark; Center for Functional Genomics and Tissue Plasticity, University of Southern Denmark, Denmark
| | - Henrik Dimke
- Department of Molecular Medicine, University of Southern Denmark, Denmark; Department of Nephrology, Odense University Hospital, Denmark
| | - Rebecca Berdeaux
- Department of Integrative Biology and Pharmacology, McGovern Medical School, UT Health Houston, USA
| | - Thomas Q de Aguiar Vallim
- Department of Medicine, Division of Cardiology, University of California, Los Angeles, USA; Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, USA
| | - Peter Olinga
- Department of Pharmaceutical Technology and Biopharmacy, University of Groningen, the Netherlands
| | - Mette M Lauridsen
- Department of Gastroenterology and Hepatology, University Hospital of South Denmark Esbjerg, Denmark; Center for Functional Genomics and Tissue Plasticity, University of Southern Denmark, Denmark
| | - Aleksander Krag
- Department of Gastroenterology and Hepatology, Odense University Hospital, Denmark; Department of Clinical Research, University of Southern Denmark, Denmark; Center for Functional Genomics and Tissue Plasticity, University of Southern Denmark, Denmark
| | - Blagoy Blagoev
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Denmark; Center for Functional Genomics and Tissue Plasticity, University of Southern Denmark, Denmark
| | - Kim Ravnskjaer
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Denmark; Center for Functional Genomics and Tissue Plasticity, University of Southern Denmark, Denmark.
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3
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Karri K, Waxman DJ. Dysregulation of murine long noncoding single-cell transcriptome in nonalcoholic steatohepatitis and liver fibrosis. RNA (NEW YORK, N.Y.) 2023; 29:977-1006. [PMID: 37015806 PMCID: PMC10275269 DOI: 10.1261/rna.079580.123] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 03/09/2023] [Indexed: 06/18/2023]
Abstract
LncRNAs comprise a heterogeneous class of RNA-encoding genes typified by low expression, nuclear enrichment, high tissue-specificity, and functional diversity, but the vast majority remain uncharacterized. Here, we assembled the mouse liver noncoding transcriptome from >2000 bulk RNA-seq samples and discovered 48,261 liver-expressed lncRNAs, a majority novel. Using these lncRNAs as a single-cell transcriptomic reference set, we elucidated lncRNA dysregulation in mouse models of high fat diet-induced nonalcoholic steatohepatitis and carbon tetrachloride-induced liver fibrosis. Trajectory inference analysis revealed lncRNA zonation patterns across the liver lobule in each major liver cell population. Perturbations in lncRNA expression and zonation were common in several disease-associated liver cell types, including nonalcoholic steatohepatitis-associated macrophages, a hallmark of fatty liver disease progression, and collagen-producing myofibroblasts, a central feature of liver fibrosis. Single-cell-based gene regulatory network analysis using bigSCale2 linked individual lncRNAs to specific biological pathways, and network-essential regulatory lncRNAs with disease-associated functions were identified by their high network centrality metrics. For a subset of these lncRNAs, promoter sequences of the network-defined lncRNA target genes were significantly enriched for lncRNA triplex formation, providing independent mechanistic support for the lncRNA-target gene linkages predicted by the gene regulatory networks. These findings elucidate liver lncRNA cell-type specificities, spatial zonation patterns, associated regulatory networks, and temporal patterns of dysregulation during hepatic disease progression. A subset of the liver disease-associated regulatory lncRNAs identified have human orthologs and are promising candidates for biomarkers and therapeutic targets.
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Affiliation(s)
- Kritika Karri
- Department of Biology, Boston University, Boston, Massachusetts 02215, USA
- Bioinformatics Program, Boston University, Boston, Massachusetts 02215, USA
| | - David J Waxman
- Department of Biology, Boston University, Boston, Massachusetts 02215, USA
- Bioinformatics Program, Boston University, Boston, Massachusetts 02215, USA
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4
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Hardesty J, Day L, Warner J, Warner D, Gritsenko M, Asghar A, Stolz A, Morgan T, McClain C, Jacobs J, Kirpich I. Hepatic Protein and Phosphoprotein Signatures of Alcohol-Associated Cirrhosis and Hepatitis. THE AMERICAN JOURNAL OF PATHOLOGY 2022; 192:1066-1082. [PMID: 35490715 PMCID: PMC9253914 DOI: 10.1016/j.ajpath.2022.04.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/08/2022] [Accepted: 04/14/2022] [Indexed: 12/12/2022]
Abstract
Alcohol-associated liver disease is a global health care burden, with alcohol-associated cirrhosis (AC) and alcohol-associated hepatitis (AH) being two clinical manifestations with poor prognosis. The limited efficacy of standard of care for AC and AH highlights a need for therapeutic targets and strategies. The current study aimed to address this need through the identification of hepatic proteome and phosphoproteome signatures of AC and AH. Proteomic and phosphoproteomic analyses were conducted on explant liver tissue (test cohort) and liver biopsies (validation cohort) from patients with AH. Changes in protein expression across AH severity and similarities and differences in AH and AC hepatic proteome were analyzed. Significant alterations in multiple proteins involved in various biological processes were observed in both AC and AH, including elevated expression of transcription factors involved in fibrogenesis (eg, Yes1-associated transcriptional regulator). Another finding was elevated levels of hepatic albumin (ALBU) concomitant with diminished ALBU phosphorylation, which may prevent ALBU release, leading to hypoalbuminemia. Furthermore, altered expression of proteins related to neutrophil function and chemotaxis, including elevated myeloperoxidase, cathelicidin antimicrobial peptide, complement C3, and complement C5 were observed in early AH, which declined at later stages. Finally, a loss in expression of mitochondria proteins, including enzymes responsible for the synthesis of cardiolipin was observed. The current study identified hepatic protein signatures of AC and AH as well as AH severity, which may facilitate the development of therapeutic strategies.
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Affiliation(s)
- Josiah Hardesty
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville, Louisville, Kentucky; Department of Pharmacology and Toxicology, University of Louisville Alcohol Center, Louisville, Kentucky
| | - Le Day
- Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington
| | - Jeffrey Warner
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville, Louisville, Kentucky; Department of Pharmacology and Toxicology, University of Louisville Alcohol Center, Louisville, Kentucky
| | - Dennis Warner
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville, Louisville, Kentucky
| | - Marina Gritsenko
- Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington
| | - Aliya Asghar
- Gastroenterology, VA Long Beach Healthcare, VA Long Beach Healthcare System, Long Beach, California
| | - Andrew Stolz
- Division of Gastrointestinal and Liver Disease, Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Timothy Morgan
- Gastroenterology, VA Long Beach Healthcare, VA Long Beach Healthcare System, Long Beach, California
| | - Craig McClain
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville, Louisville, Kentucky; Department of Pharmacology and Toxicology, University of Louisville Alcohol Center, Louisville, Kentucky; Robley Rex Veterans Medical Center, Louisville, Kentucky; University of Louisville Alcohol Center, University of Louisville School of Medicine, Louisville, Kentucky; University of Louisville Hepatobiology and Toxicology Center, University of Louisville School of Medicine, Louisville, Kentucky
| | - Jon Jacobs
- Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington
| | - Irina Kirpich
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville, Louisville, Kentucky; Department of Pharmacology and Toxicology, University of Louisville Alcohol Center, Louisville, Kentucky; University of Louisville Alcohol Center, University of Louisville School of Medicine, Louisville, Kentucky; University of Louisville Hepatobiology and Toxicology Center, University of Louisville School of Medicine, Louisville, Kentucky.
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5
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Yang L, Yue W, Zhang H, Zhang Z, Xue R, Dong C, Liu F, Chang N, Yang L, Li L. Dual Targeting of Angipoietin-1 and von Willebrand Factor by microRNA-671-5p Attenuates Liver Angiogenesis and Fibrosis. Hepatol Commun 2022; 6:1425-1442. [PMID: 35014213 PMCID: PMC9134804 DOI: 10.1002/hep4.1888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 12/12/2021] [Accepted: 12/17/2021] [Indexed: 11/08/2022] Open
Abstract
Angipoietin-1 (Angpt1) and von Willebrand factor (VWF) are two important angiogenic molecules that can drive pathologic angiogenesis and progression of liver fibrosis in our previous study. MicroRNAs (miRs) participate in a variety of physiological and pathological processes, including angiogenesis. However, the critical miRs targeting Angpt1 or VWF and potential molecular mechanism underlying liver fibrosis-associated angiogenesis is not clear yet. Human liver tissues were obtained from patients with different chronic liver diseases. Mouse models of liver fibrosis were induced by injection of CCl4 or bile duct ligation (BDL) operation. MiR-671-5p was predicted to target Angpt1 and VWF from three databases (miRanda, RNA22v2, and miRwalk). MiR-671-5p expression was decreased in the fibrotic liver of human and mice, with a negative correlation with the levels of Angpt1, VWF, sphingosine kinase-1 (SphK1, the rate-limiting enzyme for sphingosine 1-phosphate [S1P] formation), transforming growth factor β1 (TGFβ1), hypoxia inducible factor (Hif)1α, Hif2α, and fibrosis markers. Importantly, miR-671-5p expression was down-regulated in fluorescence-activated cell sorted liver sinusoidal endothelial cells and hepatic stellate cells (HSCs) in CCl4 mice compared with control mice. In vitro miR-671-5p expression was also decreased in S1P-stimulated HSCs and TGFβ1-activated liver sinusoidal endothelial cells, negatively correlated with Angpt1 and VWF expression. MiR-671-5p directly targeted Angpt1 and VWF by luciferase reporter assays. In vivo administration of miR-671-5p agomir decreased the messenger RNA and protein levels of Anpgt1 and VWF, and attenuated CCl4 -induced or BDL-induced liver angiogenesis and fibrosis. Conclusion: We identify the negative regulation of miR-671-5p on Angpt1 and VWF and liver fibrosis-associated angiogenesis, which may provide promising targets for the prevention and treatment of liver disease.
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Affiliation(s)
- Le Yang
- Department of Cell BiologyMunicipal Laboratory for Liver Protection and Regulation of RegenerationCapital Medical UniversityBeijingChina
| | - Wenhui Yue
- Department of Cell BiologyMunicipal Laboratory for Liver Protection and Regulation of RegenerationCapital Medical UniversityBeijingChina
| | - Hang Zhang
- Department of Cell BiologyMunicipal Laboratory for Liver Protection and Regulation of RegenerationCapital Medical UniversityBeijingChina
| | - Zhi Zhang
- Department of Cell BiologyMunicipal Laboratory for Liver Protection and Regulation of RegenerationCapital Medical UniversityBeijingChina
| | - Renmin Xue
- Department of Cell BiologyMunicipal Laboratory for Liver Protection and Regulation of RegenerationCapital Medical UniversityBeijingChina
| | - Chengbin Dong
- Department of Interventional TherapyBeijing Shijitan HospitalCapital Medical UniversityBeijingChina
| | - Fuquan Liu
- Department of Interventional TherapyBeijing Shijitan HospitalCapital Medical UniversityBeijingChina
| | - Na Chang
- Department of Cell BiologyMunicipal Laboratory for Liver Protection and Regulation of RegenerationCapital Medical UniversityBeijingChina
| | - Lin Yang
- Department of Cell BiologyMunicipal Laboratory for Liver Protection and Regulation of RegenerationCapital Medical UniversityBeijingChina
| | - Liying Li
- Department of Cell BiologyMunicipal Laboratory for Liver Protection and Regulation of RegenerationCapital Medical UniversityBeijingChina
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6
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Polvani S, Pepe S, Tempesti S, Tarocchi M, Marroncini G, Bencini L, Ceni E, Mello T, Picariello L, Simeone I, Grappone C, Dragoni G, Antonuzzo L, Giommoni E, Milani S, Galli A. Isoforms of the orphan nuclear receptor COUP‑TFII differentially modulate pancreatic cancer progression. Int J Oncol 2022; 60:55. [PMID: 35348189 PMCID: PMC8997336 DOI: 10.3892/ijo.2022.5345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 02/07/2022] [Indexed: 12/24/2022] Open
Abstract
The expression of the nuclear receptor transcription factor (TF) COUP-TFII is broadly associated with cell differentiation and cancer development, including of pancreatic ductal adenocarcinoma (PDAC), a devastating disease with one of the poorest prognoses among cancers worldwide. Recent studies have started to investigate the pathological and physiological roles of a novel COUP-TFII isoform (COUP-TFII_V2) that lacks the DNA-binding domain. As the role of the canonical COUP-TFII in PDAC was previously demonstrated, the present study evaluated whether COUP-TFII_V2 may have a functional role in PDAC. It was demonstrated that COUP-TFII_V2 naturally occurs in PDAC cells and in primary samples, where its expression is consistent with shorter overall survival and peripheral invasion. Of note, COUP-TFII_V2, exhibiting nuclear and cytosolic expression, is linked to epithelial to mesenchymal transition (EMT) and cancer progression, as confirmed by nude mouse experiments. The present results demonstrated that COUP-TFII_V2 distinctively regulates the EMT of PDAC and, similarly to its sibling, it is associated with tumor aggressiveness. The two isoforms have both overlapping and exclusive functions that cooperate with cancer growth and dissemination. By studying how PDAC cells switch from one isoform to the other, novel insight into cancer biology was gained, indicating that this receptor may serve as a novel possible target for PDAC management.
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Affiliation(s)
- Simone Polvani
- Gastroenterology Research Unit, Department of Experimental and Clinical Biomedical Sciences ‘Mario Serio’, University of Florence, I-50134 Florence, Italy
| | - Sara Pepe
- Core Research Laboratory, Institute for Cancer Research and Prevention, I-50139 Florence, Italy
| | - Sara Tempesti
- Gastroenterology Research Unit, Department of Experimental and Clinical Biomedical Sciences ‘Mario Serio’, University of Florence, I-50134 Florence, Italy
| | - Mirko Tarocchi
- Gastroenterology Research Unit, Department of Experimental and Clinical Biomedical Sciences ‘Mario Serio’, University of Florence, I-50134 Florence, Italy
| | - Giada Marroncini
- Endocrinology Research Unit, Department of Experimental and Clinical Biomedical Sciences ‘Mario Serio’, University of Florence, I-50139 Florence, Italy
| | - Lapo Bencini
- Oncology General Surgery, Azienda Ospedaliero Universitaria Careggi, I-50139 Florence, Italy
| | - Elisabetta Ceni
- Gastroenterology Research Unit, Department of Experimental and Clinical Biomedical Sciences ‘Mario Serio’, University of Florence, I-50134 Florence, Italy
| | - Tommaso Mello
- Gastroenterology Research Unit, Department of Experimental and Clinical Biomedical Sciences ‘Mario Serio’, University of Florence, I-50134 Florence, Italy
| | - Lucia Picariello
- Gastroenterology Research Unit, Department of Experimental and Clinical Biomedical Sciences ‘Mario Serio’, University of Florence, I-50134 Florence, Italy
| | - Irene Simeone
- Gastroenterology Research Unit, Department of Experimental and Clinical Biomedical Sciences ‘Mario Serio’, University of Florence, I-50134 Florence, Italy
| | - Cecilia Grappone
- Gastroenterology Research Unit, Department of Experimental and Clinical Biomedical Sciences ‘Mario Serio’, University of Florence, I-50134 Florence, Italy
| | - Gabriele Dragoni
- Gastroenterology Research Unit, Department of Experimental and Clinical Biomedical Sciences ‘Mario Serio’, University of Florence, I-50134 Florence, Italy
| | - Lorenzo Antonuzzo
- Department of Experimental and Clinical Medicine, University of Florence, I-50139 Florence, Italy
| | - Elisa Giommoni
- Medical Oncology, Azienda Ospedaliero Universitaria Careggi, I-50139 Florence, Italy
| | - Stefano Milani
- Gastroenterology Research Unit, Department of Experimental and Clinical Biomedical Sciences ‘Mario Serio’, University of Florence, I-50134 Florence, Italy
| | - Andrea Galli
- Gastroenterology Research Unit, Department of Experimental and Clinical Biomedical Sciences ‘Mario Serio’, University of Florence, I-50134 Florence, Italy
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7
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Abstract
Introduction: Hepatic stellate cells (HSCs) are essential for physiological homeostasis of the liver extracellular matrix (ECM). Excessive transdifferentiation of HSC from a quiescent to an activated phenotype contributes to disrupt this balance and can lead to liver fibrosis. Accumulating evidence has suggested that nuclear receptors (NRs) are involved in the regulation of HSC activation, proliferation, and function. Therefore, these NRs may be therapeutic targets to balance ECM homeostasis and inhibit HSC activation in liver fibrosis.Areas covered: In this review, the authors summarized the recent progress in the understanding of the regulatory role of NRs in HSCs and their potential as drug targets in liver fibrosis.Expert opinion: NRs are still potential therapy targets for inhibiting HSCs activation and liver fibrosis. However, the development of NRs agonists or antagonists to inhibit HSCs requires fully consideration of systemic effects.
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Affiliation(s)
- Shiyun Pu
- Department of Pharmacy, Chengdu Fifth People's Hospital, Chengdu University of TCM, Chengdu, China
| | - Hongjing Zhou
- Department of Pharmacy, Chengdu Fifth People's Hospital, Chengdu University of TCM, Chengdu, China
| | - Yan Liu
- Department of Interventional Therapy, Chengdu Fifth People's Hospital, Chengdu University of TCM, Chengdu, China
| | - Jiao Liu
- Department of Interventional Therapy, Chengdu Fifth People's Hospital, Chengdu University of TCM, Chengdu, China
- Department of Hepatobiliary Surgery, Chengdu Fifth People's Hospital, Chengdu University of TCM, Chengdu, China
| | - Yuanxin Guo
- Department of Pharmacy, Chengdu Fifth People's Hospital, Chengdu University of TCM, Chengdu, China
| | - Houfeng Zhou
- Department of Pharmacy, Chengdu Fifth People's Hospital, Chengdu University of TCM, Chengdu, China
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8
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Li L, Galichon P, Xiao X, Figueroa-Ramirez AC, Tamayo D, Lee JJK, Kalocsay M, Gonzalez-Sanchez D, Chancay MS, McCracken KW, Lee NN, Ichimura T, Mori Y, Valerius MT, Wilflingseder J, Lemos DR, Edelman ER, Bonventre JV. Orphan nuclear receptor COUP-TFII enhances myofibroblast glycolysis leading to kidney fibrosis. EMBO Rep 2021; 22:e51169. [PMID: 34031962 DOI: 10.15252/embr.202051169] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 03/28/2021] [Accepted: 04/01/2021] [Indexed: 12/11/2022] Open
Abstract
Recent studies demonstrate that metabolic disturbance, such as augmented glycolysis, contributes to fibrosis. The molecular regulation of this metabolic perturbation in fibrosis, however, has been elusive. COUP-TFII (also known as NR2F2) is an important regulator of glucose and lipid metabolism. Its contribution to organ fibrosis is undefined. Here, we found increased COUP-TFII expression in myofibroblasts in human fibrotic kidneys, lungs, kidney organoids, and mouse kidneys after injury. Genetic ablation of COUP-TFII in mice resulted in attenuation of injury-induced kidney fibrosis. A non-biased proteomic study revealed the suppression of fatty acid oxidation and the enhancement of glycolysis pathways in COUP-TFII overexpressing fibroblasts. Overexpression of COUP-TFII in fibroblasts also induced production of alpha-smooth muscle actin (αSMA) and collagen 1. Knockout of COUP-TFII decreased glycolysis and collagen 1 levels in fibroblasts. Chip-qPCR revealed the binding of COUP-TFII on the promoter of PGC1α. Overexpression of COUP-TFII reduced the cellular level of PGC1α. Targeting COUP-TFII serves as a novel treatment approach for mitigating fibrosis in chronic kidney disease and potentially fibrosis in other organs.
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Affiliation(s)
- Li Li
- Division of Renal Medicine, Brigham and Women's Hospital, Boston, MA, USA.,Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Pierre Galichon
- Division of Renal Medicine, Brigham and Women's Hospital, Boston, MA, USA.,Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Xiaoyan Xiao
- Division of Renal Medicine, Brigham and Women's Hospital, Boston, MA, USA
| | | | - Diana Tamayo
- Division of Renal Medicine, Brigham and Women's Hospital, Boston, MA, USA
| | - Jake J-K Lee
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA
| | - Marian Kalocsay
- Laboratory of Systems Pharmacology, Harvard Medical School, Boston, MA, USA.,Department of Systems Biology, Harvard Medical School, Boston, MA, USA
| | | | - Maria S Chancay
- Division of Renal Medicine, Brigham and Women's Hospital, Boston, MA, USA
| | - Kyle W McCracken
- Division of Renal Medicine, Brigham and Women's Hospital, Boston, MA, USA.,Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Nathan N Lee
- Division of Renal Medicine, Brigham and Women's Hospital, Boston, MA, USA
| | - Takaharu Ichimura
- Division of Renal Medicine, Brigham and Women's Hospital, Boston, MA, USA.,Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Yutaro Mori
- Division of Renal Medicine, Brigham and Women's Hospital, Boston, MA, USA
| | - M Todd Valerius
- Division of Renal Medicine, Brigham and Women's Hospital, Boston, MA, USA.,Department of Medicine, Harvard Medical School, Boston, MA, USA.,Harvard Stem Cell Institute, Cambridge, MA, USA
| | | | - Dario R Lemos
- Division of Renal Medicine, Brigham and Women's Hospital, Boston, MA, USA.,Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Elazer R Edelman
- Department of Medicine, Harvard Medical School, Boston, MA, USA.,Cardiovascular Division, Brigham and Women's Hospital, Boston, MA, USA.,Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Joseph V Bonventre
- Division of Renal Medicine, Brigham and Women's Hospital, Boston, MA, USA.,Department of Medicine, Harvard Medical School, Boston, MA, USA.,Laboratory of Systems Pharmacology, Harvard Medical School, Boston, MA, USA.,Harvard Stem Cell Institute, Cambridge, MA, USA
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9
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Zhao G, Weiner AI, Neupauer KM, de Mello Costa MF, Palashikar G, Adams-Tzivelekidis S, Mangalmurti NS, Vaughan AE. Regeneration of the pulmonary vascular endothelium after viral pneumonia requires COUP-TF2. SCIENCE ADVANCES 2020; 6:6/48/eabc4493. [PMID: 33239293 PMCID: PMC7688336 DOI: 10.1126/sciadv.abc4493] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 10/09/2020] [Indexed: 05/08/2023]
Abstract
Acute respiratory distress syndrome is associated with a robust inflammatory response that damages the vascular endothelium, impairing gas exchange. While restoration of microcapillaries is critical to avoid mortality, therapeutic targeting of this process requires a greater understanding of endothelial repair mechanisms. Here, we demonstrate that lung endothelium possesses substantial regenerative capacity and lineage tracing reveals that native endothelium is the source of vascular repair after influenza injury. Ablation of chicken ovalbumin upstream promoter-transcription factor 2 (COUP-TF2) (Nr2f2), a transcription factor implicated in developmental angiogenesis, reduced endothelial proliferation, exacerbating viral lung injury in vivo. In vitro, COUP-TF2 regulates proliferation and migration through activation of cyclin D1 and neuropilin 1. Upon influenza injury, nuclear factor κB suppresses COUP-TF2, but surviving endothelial cells ultimately reestablish vascular homeostasis dependent on restoration of COUP-TF2. Therefore, stabilization of COUP-TF2 may represent a therapeutic strategy to enhance recovery from pathogens, including H1N1 influenza and SARS-CoV-2.
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Affiliation(s)
- Gan Zhao
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Lung Biology Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Aaron I Weiner
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Lung Biology Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Katherine M Neupauer
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Maria Fernanda de Mello Costa
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Lung Biology Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Gargi Palashikar
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Lung Biology Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Stephanie Adams-Tzivelekidis
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Lung Biology Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Nilam S Mangalmurti
- Pulmonary, Allergy, and Critical Care Division, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Andrew E Vaughan
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
- Lung Biology Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
- Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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10
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Polvani S, Pepe S, Milani S, Galli A. COUP-TFII in Health and Disease. Cells 2019; 9:E101. [PMID: 31906104 PMCID: PMC7016888 DOI: 10.3390/cells9010101] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 12/27/2019] [Accepted: 12/29/2019] [Indexed: 12/14/2022] Open
Abstract
The nuclear receptors (NRs) belong to a vast family of evolutionary conserved proteins acting as ligand-activated transcription factors. Functionally, NRs are essential in embryogenesis and organogenesis and in adulthood they are involved in almost every physiological and pathological process. Our knowledge of NRs action has greatly improved in recent years, demonstrating that both their expression and activity are tightly regulated by a network of signaling pathways, miRNA and reciprocal interactions. The Chicken Ovalbumin Upstream Promoter Transcription Factor II (COUP-TFII, NR2F2) is a NR classified as an orphan due to the lack of a known natural ligand. Although its expression peaks during development, and then decreases considerably, in adult tissues, COUP-TFII is an important regulator of differentiation and it is variably implicated in tissues homeostasis. As such, alterations of its expression or its transcriptional activity have been studied and linked to a spectrum of diseases in organs and tissues of different origins. Indeed, an altered COUP-TFII expression and activity may cause infertility, abnormality in the vascular system and metabolic diseases like diabetes. Moreover, COUP-TFII is actively investigated in cancer research but its role in tumor progression is yet to be fully understood. In this review, we summarize the current understanding of COUP-TFII in healthy and pathological conditions, proposing an updated and critical view of the many functions of this NR.
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Affiliation(s)
- Simone Polvani
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, Gastroenterology Unit, University of Florence, viale Pieraccini 6, 50139 Firenze, Italy; (S.P.); (S.M.)
- Department of Experimental and Clinical Medicine, University of Florence, largo Brambilla 50, 50139 Firenze, Italy
| | - Sara Pepe
- Istituto per la Ricerca, la Prevenzione e la rete Oncologica (ISPRO), viale Pieraccini 6, 50139 Firenze, Italy;
- Department of Medical Biotechnologies, University of Siena, via M. Bracci 16, 53100 Siena, Italy
| | - Stefano Milani
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, Gastroenterology Unit, University of Florence, viale Pieraccini 6, 50139 Firenze, Italy; (S.P.); (S.M.)
| | - Andrea Galli
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, Gastroenterology Unit, University of Florence, viale Pieraccini 6, 50139 Firenze, Italy; (S.P.); (S.M.)
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11
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Yu F, Dong B, Dong P, He Y, Zheng J, Xu P. Hypoxia induces the activation of hepatic stellate cells through the PVT1-miR-152-ATG14 signaling pathway. Mol Cell Biochem 2019; 465:115-123. [PMID: 31893334 DOI: 10.1007/s11010-019-03672-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Accepted: 12/01/2019] [Indexed: 02/07/2023]
Abstract
Increasing studies have indicated that hypoxia serves as a pivotal microenvironmental factor that facilitates activation of hepatic stellate cells (HSCs). However, the mechanism by which hypoxia activates HSCs is not clear. Here, we demonstrated that plasmacytoma variant translocation 1 (PVT1) and autophagy were overexpressed in liver fibrotic specimens. In primary mouse HSCs, both PVT1 and autophagy were induced by hypoxia. Further study showed that hypoxia-induced autophagy depended on expression of PVT1 and miR-152 in HSCs. Luciferase reporter assay indicated that autophagy-related gene 14 (ATG14) was a direct target of miR-152. In addition, inhibition of autophagy by 3-methyladenine and Beclin-1 siRNA impeded activation of HSCs cultured in 1% O2. Taken together, autophagy induction via the PVT1-miR-152-ATG14 signaling pathway contributes to activation of HSCs under hypoxia condition.
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Affiliation(s)
- Fujun Yu
- Department of Gastroenterology, Shanghai Songjiang District Central Hospital, Shanghai, China
- Department of Gastroenterology, Songjiang Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (Preparatory Stage), Shanghai, China
- Department of Gastroenterology, Shanghai Songjiang Clinical Medical College of Nanjing Medical University, Shanghai, China
- Department of Gastroenterology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Buyuan Dong
- Department of Gastroenterology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Peihong Dong
- Department of Infectious Diseases, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Yanghuan He
- Department of Gastroenterology, Shanghai Songjiang District Central Hospital, Shanghai, China
| | - Jianjian Zheng
- Key Laboratory of Diagnosis and Treatment of Severe Hepato-Pancreatic Diseases of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Nanbaixiang, Ouhai District, Wenzhou, Zhejiang, China.
| | - Ping Xu
- Department of Gastroenterology, Shanghai Songjiang District Central Hospital, Shanghai, China.
- Department of Gastroenterology, Songjiang Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (Preparatory Stage), Shanghai, China.
- Department of Gastroenterology, Shanghai Songjiang Clinical Medical College of Nanjing Medical University, Shanghai, China.
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12
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Byun JK, Park M, Yun JW, Lee J, Kim JS, Cho SJ, Lee YM, Lee IK, Choi YK, Park KG. Oncogenic KRAS signaling activates mTORC1 through COUP-TFII-mediated lactate production. EMBO Rep 2019; 20:embr.201847451. [PMID: 30988000 DOI: 10.15252/embr.201847451] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 03/22/2019] [Accepted: 03/27/2019] [Indexed: 12/20/2022] Open
Abstract
Oncogenic signals contribute to enhanced glycolysis and mTORC1 activity, leading to rapid cell proliferation in cancer. Regulation of glycolysis and mTORC1 by PI3K/Akt signaling is well established, but how KRAS-induced MEK signaling regulates these pathways remains poorly understood. Here, we report a role for MEK-driven lactate production in mTORC1 activation in KRAS-activated cells. KRAS/MEK-induced upregulation of the chicken ovalbumin upstream promoter transcriptional factor II (COUP-TFII) increases the expression of lactate dehydrogenase A (LDHA), resulting in lactate production and mTORC1 activation. Further, lactate inhibits the interaction of TSC2 and Rheb, leading to the cellular activation of mTORC1 irrespective of growth factor stimulation. These findings suggest that COUP-TFII is a novel oncogenic mediator, connecting KRAS signaling and glycolysis, and leading to mTORC1 activation and cellular growth.
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Affiliation(s)
- Jun-Kyu Byun
- Research Institute of Pharmaceutical Science, College of Pharmacy, Kyungpook National University, Daegu, Korea
| | - Mihyang Park
- Department of Biomedical Science, Graduate School, Kyungpook National University, Daegu, Korea.,BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University, Daegu, Korea
| | - Jae Won Yun
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.,Samsung Advanced Institute of Health Science and Technology, Sungkyunkwan University, Seoul, Korea
| | - Jaebon Lee
- Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jae Sun Kim
- Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Sung Jin Cho
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, Korea
| | - You Mie Lee
- Research Institute of Pharmaceutical Science, College of Pharmacy, Kyungpook National University, Daegu, Korea
| | - In-Kyu Lee
- Department of Internal Medicine, School of Medicine, Kyungpook National University Kyungpook National University Hospital, Daegu, Korea
| | - Yeon-Kyung Choi
- Department of Internal Medicine, School of Medicine, Kyungpook National University Kyungpook National University Hospital, Daegu, Korea
| | - Keun-Gyu Park
- Department of Internal Medicine, School of Medicine, Kyungpook National University Kyungpook National University Hospital, Daegu, Korea
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13
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Song W, Ovcharenko I. Dichotomy in redundant enhancers points to presence of initiators of gene regulation. BMC Genomics 2018; 19:947. [PMID: 30563465 PMCID: PMC6299655 DOI: 10.1186/s12864-018-5335-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 11/29/2018] [Indexed: 12/31/2022] Open
Abstract
Background The regulatory landscape of a gene locus often consists of several functionally redundant enhancers establishing phenotypic robustness and evolutionary stability of its regulatory program. However, it is unclear what mechanisms are employed by redundant enhancers to cooperatively orchestrate gene expression. Results By comparing redundant enhancers to single enhancers (enhancers present in a single copy in a gene locus), we observed that the DNA sequence encryption differs between these two classes of enhancers, suggesting a difference in their regulatory mechanisms. Initiator enhancers, which are a subset of redundant enhancers and show similar sequence encryption to single enhancers, differ from the rest of redundant enhancers in their sequence encryption, evolutionary conservation and proximity to target genes. Genes hosting initiator enhancers in their loci feature elevated levels of expression. Initiator enhancers show a high level of 3D chromatin contacts with both transcription start sites and regular enhancers, suggesting their roles as primary activators and intermediate catalysts of gene expression, through which the regulatory signals of redundant enhancers are propagated to the target genes. In addition, GWAS and eQTLs variants are significantly enriched in initiator enhancers compared to redundant enhancers, suggesting a key functional role these sequences play in gene regulation. Conclusions The specific characteristics and widespread abundance of initiator enhancers advocate for a possible universal hierarchical mechanism of tissue-specific gene regulation involving multiple redundant enhancers acting through initiator enhancers. Electronic supplementary material The online version of this article (10.1186/s12864-018-5335-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Wei Song
- Computational Biology Branch, National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, USA
| | - Ivan Ovcharenko
- Computational Biology Branch, National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, USA.
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14
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Fu JL, Hsiao KY, Lee HC, Li WN, Chang N, Wu MH, Tsai SJ. Suppression of COUP-TFII upregulates angiogenin and promotes angiogenesis in endometriosis. Hum Reprod 2018; 33:1517-1527. [DOI: 10.1093/humrep/dey220] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 05/16/2018] [Accepted: 05/26/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- Jhao-Lin Fu
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Kuei-Yang Hsiao
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Hsiu-Chi Lee
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Wan-Ning Li
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Ning Chang
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Meng-Hsing Wu
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Obstetrics & Gynecology, National Cheng Kung University Hospital, Tainan, Taiwan
| | - Shaw-Jenq Tsai
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
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15
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Hypoxic Signaling and Cholesterol Lipotoxicity in Fatty Liver Disease Progression. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:2548154. [PMID: 29955245 PMCID: PMC6000860 DOI: 10.1155/2018/2548154] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 04/30/2018] [Accepted: 05/14/2018] [Indexed: 02/06/2023]
Abstract
Cholesterol is the only lipid whose absorption in the gastrointestinal tract is limited by gate-keeping transporters and efflux mechanisms, preventing its rapid absorption and accumulation in the liver and blood vessels. In this review, I explored the current data regarding cholesterol accumulation in liver cells and key mechanisms in cholesterol-induced fatty liver disease associated with the activation of deleterious hypoxic and nitric oxide signal transduction pathways. Although nonalcoholic fatty liver disease (NAFLD) affects both obese and nonobese individuals, the mechanism of NAFLD progression in lean individuals with healthy metabolism is puzzling. Lean NAFLD individuals exhibit normal metabolic responses, implying that liver damage is not associated with impaired metabolism per se and that direct lipotoxic effects are crucial for disease progression. Several redox and oxidant signaling pathways involving cholesterol are at play in fatty liver disease development. These include impairment of the mitochondrial and lysosomal function by cholesterol loading of the inner-cell membranes; formation of cholesterol crystals and hepatocyte degradation; and crown-like structures surrounding degrading hepatocytes, activating Kupffer cells, and evoking inflammation. The current review focuses on the induction of liver inflammation, fibrosis, and steatosis by free cholesterol via the hypoxia-inducible factor 1α (HIF-1α), a main oxygen-sensing transcription factor involved in all stages of NAFLD. Cholesterol loading in hepatocytes can result in chronic HIF-1α activity because of the decreased oxygen availability and excessive production of nitric oxide and mitochondrial reactive oxygen species.
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16
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PPAR γ Antagonizes Hypoxia-Induced Activation of Hepatic Stellate Cell through Cross Mediating PI3K/AKT and cGMP/PKG Signaling. PPAR Res 2018; 2018:6970407. [PMID: 29686697 PMCID: PMC5852857 DOI: 10.1155/2018/6970407] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 12/20/2017] [Indexed: 12/12/2022] Open
Abstract
Background and Aims Accumulating evidence reveals that PPARγ plays a unique role in the regulation of hepatic fibrosis and hepatic stellate cells (HSCs) activation. This study was aimed at investigating the role of PPARγ in hypoxia-induced hepatic fibrogenesis and its possible mechanism. Methods Rats used for CCl4-induced hepatic fibrosis model were exposed to hypoxia for 8 hours each day. Rats exposed to hypoxia were treated with or without the PPARγ agonist rosiglitazone. Liver sections were stained with HE and Sirius red staining 8 weeks later. HSCs were exposed to hypoxic environment in the presence or absence of rosiglitazone, and expression of PPARγ and two fibrosis markers, α-SMA and desmin, were measured using western blot and immunofluorescence staining. Next, levels of PPARγ, α-SMA, and desmin as well as PKG and cGMP activity were detected using PI3K/AKT and a cGMP activator or inhibitor. Results Hypoxia promoted the induction and progress of hepatic fibrosis and HSCs activation. Meanwhile, rosiglitazone significantly antagonized the effects induced by hypoxia. Signaling by sGC/cGMP/PKG promoted the inhibitory effect of PPARγ on hypoxia-induced activation of HSCs. Moreover, PI3K/AKT signaling or PDE5 blocked the above response of PPARγ. Conclusion sGC/cGMP/PKG and PI3K/AKT signals act on PPARγ synergistically to attenuate hypoxia-induced HSC activation.
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