1
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Nail AN, Spear BT, Peterson ML. Highly homologous mouse Cyp2a4 and Cyp2a5 genes are differentially expressed in the liver and both express long non-coding antisense RNAs. Gene 2020; 767:145162. [PMID: 32987105 DOI: 10.1016/j.gene.2020.145162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 09/04/2020] [Accepted: 09/17/2020] [Indexed: 11/16/2022]
Abstract
The mammalian Cytochrome P450 (Cyp) gene superfamily encodes enzymes involved in numerous metabolic pathways and are frequently expressed in the liver. Despite the remarkably high sequence similarity of Cyp2a4 and Cyp2a5 genes and their surrounding genomic regions, they exhibit differences in expression in the adult mouse liver. For example, Cyp2a4 is highly female-biased whereas Cyp2a5 is only moderately female-biased and Cyp2a4, but not Cyp2a5, is activated in liver cancer. We hypothesized that the limited sequence differences may help us identify the basis for this differential expression. An antisense expressed sequence tag had been uniquely annotated to the Cyp2a4 gene which led us to investigate this transcript as a possible regulator of this gene. We characterized the full-length antisense transcript and also discovered a similar transcript in the Cyp2a5 gene. These transcripts are nuclear long noncoding RNAs that are expressed similarly to their sense mRNA counterparts. This includes the sex-biased and liver tumor differences seen between the Cyp2a4 and Cyp2a5 genes, but we also find that these two genes and their antisense transcripts are expressed within different zones of the liver structure. Interestingly, while the differences in sex-biased expression of the mRNAs are established 1-2 months after birth, the antisense transcripts exhibit these expression differences earlier, at 3-4 weeks after birth. By analyzing published genomic data, we have identified candidate transcription factor binding sites that could account for differences in Cyp2a4/Cyp2a5 expression. Taken together, these studies characterize the first antisense RNAs within the Cyp supergene family and identify potential transcriptional and post-transcriptional mechanisms governing different Cyp2a4 and Cyp2a5 expression patterns in mouse liver.
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Affiliation(s)
- Alexandra N Nail
- Department of Microbiology, Immunology and Molecular Genetics, USA
| | - Brett T Spear
- Department of Microbiology, Immunology and Molecular Genetics, USA; Markey Cancer Center, University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | - Martha L Peterson
- Department of Microbiology, Immunology and Molecular Genetics, USA; Markey Cancer Center, University of Kentucky College of Medicine, Lexington, KY 40536, USA.
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2
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Liu P, Lu D, Al-Ameri A, Wei X, Ling S, Li J, Zhu H, Xie H, Zhu L, Zheng S, Xu X. Glutamine synthetase promotes tumor invasion in hepatocellular carcinoma through mediating epithelial-mesenchymal transition. Hepatol Res 2020; 50:246-257. [PMID: 31652385 DOI: 10.1111/hepr.13433] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 08/05/2019] [Accepted: 08/09/2019] [Indexed: 12/14/2022]
Abstract
AIM Glutamine synthetase (GS) levels increase gradually with the development of hepatocellular carcinogenesis. In this study, we aimed to investigate the clinical significance of GS and the underlying mechanism of GS promoting hepatocellular carcinoma (HCC) invasion. METHODS Serum concentration of GS and α-fetoprotein (AFP) in HCC patients, liver cirrhosis patients, and healthy individuals were detected. The GS-mRNA level and its prognostic value were explored in an independent HCC cohort from The Cancer Genome Atlas database. GS expression in HCC tissue and matched para-tumor tissue was determined. The effect of GS on HCC invasion was assessed in vitro and in vivo. RESULTS The serum GS and AFP level in HCC patients was higher than that in healthy controls and liver cirrhosis patients. The area under the receiver operating characteristic curve for HCC diagnosis was 0.848 and 0.861 for GS and AFP, respectively. The area under the receiver operating characteristic curve of GS for diagnosis of AFP-negative HCC was 0.913. Combining GS with AFP achieved a diagnostic sensitivity and specificity of 82.5% and 93%, respectively. The GS level was higher in tumor tissues than that in para-tumor tissues. High GS expression was associated with poor prognosis of moderately differentiated HCC patients. In vitro, GS exerted an influence on HCC cell migration by mediating epithelial-mesenchymal transition. The lung and liver metastatic model of HCC further confirmed that GS expression affected the invasion of HCC cells in vivo. CONCLUSIONS GS is a useful biomarker for HCC diagnosis, especially for AFP-negative patients. In addition, GS affects HCC metastasis through mediating epithelial-mesenchymal transition.
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Affiliation(s)
- Peng Liu
- Department of Surgery, Division of Hepatobiliary and Pancreatic Surgery, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHFPC Key Laboratory of Combined Multi-organ Transplantation, Hangzhou, China
| | - Di Lu
- Department of Surgery, Division of Hepatobiliary and Pancreatic Surgery, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHFPC Key Laboratory of Combined Multi-organ Transplantation, Hangzhou, China
| | - Abdulahad Al-Ameri
- Department of Surgery, Division of Hepatobiliary and Pancreatic Surgery, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHFPC Key Laboratory of Combined Multi-organ Transplantation, Hangzhou, China
| | - Xuyong Wei
- Department of Surgery, Division of Hepatobiliary and Pancreatic Surgery, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHFPC Key Laboratory of Combined Multi-organ Transplantation, Hangzhou, China
| | - Sunbin Ling
- Department of Surgery, Division of Hepatobiliary and Pancreatic Surgery, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHFPC Key Laboratory of Combined Multi-organ Transplantation, Hangzhou, China
| | - Jie Li
- Department of Surgery, Division of Hepatobiliary and Pancreatic Surgery, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHFPC Key Laboratory of Combined Multi-organ Transplantation, Hangzhou, China
| | - Hai Zhu
- Department of Surgery, Division of Hepatobiliary and Pancreatic Surgery, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHFPC Key Laboratory of Combined Multi-organ Transplantation, Hangzhou, China
| | - Haiyang Xie
- Department of Surgery, Division of Hepatobiliary and Pancreatic Surgery, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHFPC Key Laboratory of Combined Multi-organ Transplantation, Hangzhou, China.,Key Laboratory of the diagnosis and treatment of organ Transplantation, Hangzhou, China.,Key Laboratory of Organ Transplantation, Zhejiang Province, Hangzhou, China.,Collaborative innovation center for Diagnosis treatment of infectious diseases, Hangzhou, China
| | - Liming Zhu
- Department of Abdominal Medical oncology, Zhejiang, Cancer Hospital, Hangzhou, China
| | - Shusen Zheng
- Department of Surgery, Division of Hepatobiliary and Pancreatic Surgery, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHFPC Key Laboratory of Combined Multi-organ Transplantation, Hangzhou, China.,Key Laboratory of the diagnosis and treatment of organ Transplantation, Hangzhou, China.,Key Laboratory of Organ Transplantation, Zhejiang Province, Hangzhou, China.,Collaborative innovation center for Diagnosis treatment of infectious diseases, Hangzhou, China
| | - Xiao Xu
- Department of Surgery, Division of Hepatobiliary and Pancreatic Surgery, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHFPC Key Laboratory of Combined Multi-organ Transplantation, Hangzhou, China.,Key Laboratory of the diagnosis and treatment of organ Transplantation, Hangzhou, China.,Key Laboratory of Organ Transplantation, Zhejiang Province, Hangzhou, China.,Collaborative innovation center for Diagnosis treatment of infectious diseases, Hangzhou, China
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3
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Clinkenbeard EL, Turpin C, Jiang J, Peterson ML, Spear BT. Liver size and lipid content differences between BALB/c and BALB/cJ mice on a high-fat diet are due, in part, to Zhx2. Mamm Genome 2019; 30:226-236. [PMID: 31321500 DOI: 10.1007/s00335-019-09811-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 07/09/2019] [Indexed: 11/26/2022]
Abstract
BALB/cJ mice exhibit considerable phenotypic differences with other BALB/c substrains. Some of these traits involve the liver, including persistent postnatal expression of genes that are normally expressed only in the fetal liver and reduced expression of major urinary proteins. These traits are due to a mutation that dramatically reduces expression of the gene encoding the transcription factor Zinc fingers and homeoboxes 2 (Zhx2). BALB/cJ mice also exhibit reduced serum lipid levels and resistance to atherosclerosis compared to other mouse strains when placed on a high-fat diet. This trait is also due, at least in part, to the Zhx2 mutation. Microarray analysis identified many genes affecting lipid homeostasis, including Lipoprotein lipase, that are dysregulated in BALB/cJ liver. This led us to investigate whether hepatic lipid levels would be different between BALB/cJ and BALB/c mice when placed on a normal chow or a high-fat chow diet. On the high-fat chow, BALB/cJ mice had increased weight gain, increased liver:body weight ratio, elevated hepatic lipid accumulation and markers of liver damage when compared to BALB/c mice. These traits in BALB/cJ mice were only partially reversed by a hepatocyte-specific Zhx2 transgene. These data indicate that Zhx2 reduces liver lipid levels and is hepatoprotective in mice on a high-fat diet, but the partial rescue by the Zhx2 transgene suggests a contribution by both parenchymal and non-parenchymal cells. A model to account for the cardiovascular and liver phenotype in mice with reduced Zhx2 levels is provided.
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Affiliation(s)
- Erica L Clinkenbeard
- Department of Microbiology, Immunology & Molecular Genetics, University of Kentucky College of Medicine, Lexington, KY, 40536, USA
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Courtney Turpin
- Department of Pharmacology & Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, 40536, USA
| | - Jieyun Jiang
- Department of Microbiology, Immunology & Molecular Genetics, University of Kentucky College of Medicine, Lexington, KY, 40536, USA
| | - Martha L Peterson
- Department of Microbiology, Immunology & Molecular Genetics, University of Kentucky College of Medicine, Lexington, KY, 40536, USA
- Markey Cancer Center, University of Kentucky College of Medicine, Lexington, KY, 40536, USA
| | - Brett T Spear
- Department of Microbiology, Immunology & Molecular Genetics, University of Kentucky College of Medicine, Lexington, KY, 40536, USA.
- Markey Cancer Center, University of Kentucky College of Medicine, Lexington, KY, 40536, USA.
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4
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Kang JY, Kim M, Kang Y, Lee W, Ha TK, Seo JH, Son YG, Ha E. Thyroidectomy stimulates glucagon-like peptide-1 secretion and attenuates hepatic steatosis in high-fat fed rats. Biochem Biophys Res Commun 2017; 493:548-555. [PMID: 28870812 DOI: 10.1016/j.bbrc.2017.08.154] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 08/31/2017] [Indexed: 02/07/2023]
Abstract
Thyroid hormones (THs) as a therapeutic intervention to treat obesity has been tried but the effect of THs on body weight and the mechanistic details of which are far from clear. This study was designed to determine and elucidate the mechanistic details of metabolic action of THs in high-fat diet (HFD) fed Sprague Dawley (SD) rats. Rats were made surgically hypothyroid (thyroidectomy, Thx). Body weights and food and water intake profoundly decreased in HFD fed thyroidectomized group (HN Thx). Results showed that delayed insulin response, increased total cholesterol, high-density lipoprotein, and low-density lipoprotein in HN Thx. Unexpectedly, however, Thx reduced serum and hepatic triglyceride concentrations. Further studies revealed that Thx dramatically increased circulating GLP-1 as well as increased expressions of GLP-1 in small intestine. Diminished hepatic expressions of lipogenic genes, were observed in HN Thx group. Beta-catenin and glutamine synthetase, a known target of β-catenin, were up-regulated in the liver of HN Thx group. The expressions of gluconeogenic genes G6P and PCK were reduced in the liver of HN Thx group. The results may suggest that surgery-induced hypothyroidism increases GLP-1, the actions of which may in part be responsible for the reduction in water intake, appetite and hepatic steatosis.
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Affiliation(s)
- Jong Yeon Kang
- Department of Biochemistry, School of Medicine, Keimyung University, Daegu, Republic of Korea
| | - Mikyung Kim
- Department of Biochemistry, School of Medicine, Keimyung University, Daegu, Republic of Korea
| | - Yuna Kang
- Department of Pathology, School of Medicine, Keimyung University, Daegu, Republic of Korea
| | - Wonmok Lee
- Department of Laboratory Medicine, School of Medicine, Keimyung University, Daegu, Republic of Korea
| | - Tae Kyung Ha
- Department of Surgery, College of Medicine, Hanyang University, Seoul, Republic of Korea
| | - Ji Hae Seo
- Department of Biochemistry, School of Medicine, Keimyung University, Daegu, Republic of Korea
| | - Young Gil Son
- Department of Surgery, School of Medicine, Keimyung University, Daegu, Republic of Korea.
| | - Eunyoung Ha
- Department of Biochemistry, School of Medicine, Keimyung University, Daegu, Republic of Korea.
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5
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Pozdeev VI, Lang E, Görg B, Bidmon HJ, Shinde PV, Kircheis G, Herebian D, Pfeffer K, Lang F, Häussinger D, Lang KS, Lang PA. TNFα induced up-regulation of Na +,K +,2Cl - cotransporter NKCC1 in hepatic ammonia clearance and cerebral ammonia toxicity. Sci Rep 2017; 7:7938. [PMID: 28801579 PMCID: PMC5554233 DOI: 10.1038/s41598-017-07640-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 06/28/2017] [Indexed: 12/21/2022] Open
Abstract
The devastating consequences of hepatic failure include hepatic encephalopathy, a severe, life threatening impairment of neuronal function. Hepatic encephalopathy is caused by impaired hepatic clearance of NH4+. Cellular NH4+ uptake is accomplished mainly by the Na+,K+,2Cl− cotransporter. Here we show that hepatic clearance of NH4+ is impaired in TNFα deficient as well as TNFR1&TNFR2 double knockout mice, which both develop hyperammonemia. Despite impaired hepatic clearance of NH4+, TNFα deficient mice and TNFR1 deficient mice were protected against acute ammonia intoxication. While 54% of the wild-type mice and 60% of TNFR2 deficient mice survived an NH4+ load, virtually all TNFα deficient mice and TNFR1 deficient mice survived the treatment. Conversely, TNFα treatment of wild type mice sensitized the animals to the toxic effects of an NH4+ load. The protection of TNFα-deficient mice against an NH4+ load was paralleled by decreased cerebral expression of NKCC1. According to the present observations, inhibition of TNFα formation and/or NKCC1 may be strategies to favorably influence the clinical course of hepatic encephalopathy.
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Affiliation(s)
- Vitaly I Pozdeev
- Department of Gastroenterology, Hepatology, and Infectious Diseases, Heinrich-Heine-University Düsseldorf, Universitätsstr. 1, 40225, Düsseldorf, Germany.,Department of Molecular Medicine II, Medical Faculty, Heinrich Heine University, Universitätsstr. 1, 40225, Düsseldorf, Germany
| | - Elisabeth Lang
- Department of Gastroenterology, Hepatology, and Infectious Diseases, Heinrich-Heine-University Düsseldorf, Universitätsstr. 1, 40225, Düsseldorf, Germany
| | - Boris Görg
- Department of Gastroenterology, Hepatology, and Infectious Diseases, Heinrich-Heine-University Düsseldorf, Universitätsstr. 1, 40225, Düsseldorf, Germany
| | - Hans J Bidmon
- C.&O. Vogt Institute for Brain Research, Heinrich-Heine-University Düsseldorf, 40225, Düsseldorf, Germany
| | - Prashant V Shinde
- Department of Molecular Medicine II, Medical Faculty, Heinrich Heine University, Universitätsstr. 1, 40225, Düsseldorf, Germany
| | - Gerald Kircheis
- Department of Gastroenterology, Hepatology, and Infectious Diseases, Heinrich-Heine-University Düsseldorf, Universitätsstr. 1, 40225, Düsseldorf, Germany
| | - Diran Herebian
- Department of General Pediatrics, Neonatology, and Pediatric Cardiology, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany
| | - Klaus Pfeffer
- Institute of Medical Microbiology and Hospital Hygiene, Heinrich-Heine- University Düsseldorf, 40225, Duesseldorf, Germany
| | - Florian Lang
- Department of Molecular Medicine II, Medical Faculty, Heinrich Heine University, Universitätsstr. 1, 40225, Düsseldorf, Germany.,Department of Internal Medicine III, Eberhard-Karls Universitaet Tuebingen, Tuebingen, Germany
| | - Dieter Häussinger
- Department of Gastroenterology, Hepatology, and Infectious Diseases, Heinrich-Heine-University Düsseldorf, Universitätsstr. 1, 40225, Düsseldorf, Germany
| | - Karl S Lang
- Institute of Immunology, Medical Faculty, University of Duisburg-Essen, Hufelandstr. 55, Essen, 45147, Germany
| | - Philipp A Lang
- Department of Molecular Medicine II, Medical Faculty, Heinrich Heine University, Universitätsstr. 1, 40225, Düsseldorf, Germany.
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6
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Kardos J, Héja L, Jemnitz K, Kovács R, Palkovits M. The nature of early astroglial protection-Fast activation and signaling. Prog Neurobiol 2017; 153:86-99. [PMID: 28342942 DOI: 10.1016/j.pneurobio.2017.03.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 09/22/2016] [Accepted: 03/05/2017] [Indexed: 12/14/2022]
Abstract
Our present review is focusing on the uniqueness of balanced astroglial signaling. The balance of excitatory and inhibitory signaling within the CNS is mainly determined by sharp synaptic transients of excitatory glutamate (Glu) and inhibitory γ-aminobutyrate (GABA) acting on the sub-second timescale. Astroglia is involved in excitatory chemical transmission by taking up i) Glu through neurotransmitter-sodium transporters, ii) K+ released due to presynaptic action potential generation, and iii) water keeping osmotic pressure. Glu uptake-coupled Na+ influx may either ignite long-range astroglial Ca2+ transients or locally counteract over-excitation via astroglial GABA release and increased tonic inhibition. Imbalance of excitatory and inhibitory drives is associated with a number of disease conditions, including prevalent traumatic and ischaemic injuries or the emergence of epilepsy. Therefore, when addressing the potential of early therapeutic intervention, astroglial signaling functions combating progress of Glu excitotoxicity is of critical importance. We suggest, that excitotoxicity is linked primarily to over-excitation induced by the impairment of astroglial Glu uptake and/or GABA release. Within this framework, we discuss the acute alterations of Glu-cycling and metabolism and conjecture the therapeutic promise of regulation. We also confer the role played by key carrier proteins and enzymes as well as their interplay at the molecular, cellular, and organ levels. Moreover, based on our former studies, we offer potential prospect on the emerging theme of astroglial succinate sensing in course of Glu excitotoxicity.
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Affiliation(s)
- Julianna Kardos
- Functional Pharmacology Research Group, Institute of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Hungary.
| | - László Héja
- Functional Pharmacology Research Group, Institute of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Hungary
| | - Katalin Jemnitz
- Functional Pharmacology Research Group, Institute of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Hungary
| | - Richárd Kovács
- Institute of Neurophysiology, Charité - Universitätsmedizin, Berlin, Germany
| | - Miklós Palkovits
- Human Brain Tissue Bank and Laboratory, Semmelweis University, Budapest, Hungary
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7
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Salleng KJ, Revetta FL, Deane NG, Washington MK. The Applicability of a Human Immunohistochemical Panel to Mouse Models of Hepatocellular Neoplasia. Comp Med 2015; 65:398-408. [PMID: 26473343 PMCID: PMC4617330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 09/04/2014] [Accepted: 06/03/2015] [Indexed: 06/05/2023]
Abstract
Various immunohistochemical panels are used as aids to distinguish between primary hepatocellular malignancies and metastatic tumors and between benign lesions and carcinomas. We compared the immunohistochemical spectrum of hepatocellular lesions in mice with that of human hepatocellular carcinoma (HCC). Specifically, we compared the staining parameters of 128 murine foci of cellular alteration (FCA) and tumors (adenoma and HCC) from archival tissue blocks of 3 transgenic mouse models (LFABP-cyclin D1, Alb1-TGFβ1, and LFABP-cyclin D1 × Alb1-TGFβ1) with those of archival human HCC (n = 5). Antibodies were chosen according to their published performance and characterization in human hepatocellular tumor diagnosis and included: arginase 1 (Arg1), β-catenin, glutamine synthetase (GS), glypican 3, hepatocyte paraffin 1 (HepPar1), and cytokeratin 19 (CK19). GS was the single best immunostain for identifying hepatocellular tumors in mice, with 100% positive staining. Data showed a trend toward loss of normal function (staining) with Arg1, with a higher percentage of positive staining in FCA than in adenomas and HCC. All FCA lacked murine β-catenin nuclear translocation, which was present in 2 of the 7 adenomas and 22 of the 96 HCC tested. HepPar1 staining was lower than anticipated, except in trabecular HCC (16 of 22 samples were positive). Glyp3 stained very lightly, and only scattered CK19-positive cells were noted (4 of 44 cases of mouse trabecular HCC). Thus, GS appears to be the most useful marker for identifying neoplasia in the transgenic mouse models we tested and should be included in immunohistochemistry assessing hepatocellular neoplasia development.
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Key Words
- arg1, arginase 1
- ck19, cytokeratin 19
- fca, foci of cellular alterations
- gs, glutamine synthetase
- glyp3, glypican 3
- heppar1, hepatocyte paraffin 1
- hcc, hepatocellular carcinoma
- hsp70, heat-shock protein 70
- lfabp, liver fatty acid binding protein
- pcea, polyclonal carcinoembryonic antigen
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Affiliation(s)
- Kenneth J Salleng
- Department of Pathology, Microbiology, and Immunology, Section on Comparative Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
| | - Frank L Revetta
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Natasha G Deane
- Department of Surgery, Division of Surgical Oncology, and Radiology, Division of Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - M Kay Washington
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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8
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Hyperammonemia in gene-targeted mice lacking functional hepatic glutamine synthetase. Proc Natl Acad Sci U S A 2015; 112:5521-6. [PMID: 25870278 DOI: 10.1073/pnas.1423968112] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Urea cycle defects and acute or chronic liver failure are linked to systemic hyperammonemia and often result in cerebral dysfunction and encephalopathy. Although an important role of the liver in ammonia metabolism is widely accepted, the role of ammonia metabolizing pathways in the liver for maintenance of whole-body ammonia homeostasis in vivo remains ill-defined. Here, we show by generation of liver-specific Gln synthetase (GS)-deficient mice that GS in the liver is critically involved in systemic ammonia homeostasis in vivo. Hepatic deletion of GS triggered systemic hyperammonemia, which was associated with cerebral oxidative stress as indicated by increased levels of oxidized RNA and enhanced protein Tyr nitration. Liver-specific GS-deficient mice showed increased locomotion, impaired fear memory, and a slightly reduced life span. In conclusion, the present observations highlight the importance of hepatic GS for maintenance of ammonia homeostasis and establish the liver-specific GS KO mouse as a model with which to study effects of chronic hyperammonemia.
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9
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Vázquez-Martínez O, De Ita-Pérez D, Valdés-Fuentes M, Flores-Vidrio A, Vera-Rivera G, Miranda MI, Méndez I, Díaz-Muñoz M. Molecular and biochemical modifications of liver glutamine synthetase elicited by daytime restricted feeding. Liver Int 2014; 34:1391-401. [PMID: 25368882 DOI: 10.1111/liv.12412] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND & AIMS The circadian clock system in the liver plays important roles in regulating metabolism and energy homeostasis. Restricted feeding schedules (RFS) become an entraining stimulus that promotes adaptations that form part of an alternative circadian clock known as the food entrained oscillator (FEO). The aim of this study was to evaluate the daily variations of glutamine synthetase (GS) in liver under a daytime RFS. METHODS Hepatic GS properties were analysed at 3-h intervals over a 24-h period in adult male Wistar rats maintained in a 12:12 h light–dark cycle. RFS group: food access for 2-h in light phase, during 3 weeks. AL group: feeding ad libitum. Fa group: acute fast (21 h). Fa–Re group: acute fast followed by refed 2 h.mRNA expression was measured by RT-qPCR, protein presence by Western-blot and immunohistochemistry, enzyme activity by a spectrophotometric assay, and glutamine by high pressure liquid chromatography. RESULTS AND CONCLUSIONS Restricted feeding schedule induced circadian rhythmicity inmRNA levels of GS and the loss of the rhythmic pattern in mitochondrial GS activity. GS activity in liver homogenates displayed a robust rhythmic pattern in AL that was not modified by RFS. The presence of GS and its zonal distribution did not show rhythmic pattern in both groups. However, acute Fa and Fa–Re diminished GS protein and activity in liver homogenates. Hepatic glutamine concentrations showed a 24-h rhythmic pattern in both groups, in an antiphasic pattern. In conclusion, daytime RFS influences the liver GS system at different levels, that could be part of rheostatic adaptations associated to the FEO, and highlight the plasticity of this system.
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Affiliation(s)
- Olivia Vázquez-Martínez
- Department of Cellular and Molecular Neurobiology; Instituto de Neurobiología; Universidad Nacional Autónoma de México (UNAM); Querétaro Mexico
| | - Dalia De Ita-Pérez
- Department of Cellular and Molecular Neurobiology; Instituto de Neurobiología; Universidad Nacional Autónoma de México (UNAM); Querétaro Mexico
| | - Marlen Valdés-Fuentes
- Department of Cellular and Molecular Neurobiology; Instituto de Neurobiología; Universidad Nacional Autónoma de México (UNAM); Querétaro Mexico
| | - Alejandra Flores-Vidrio
- Department of Cellular and Molecular Neurobiology; Instituto de Neurobiología; Universidad Nacional Autónoma de México (UNAM); Querétaro Mexico
| | - Gabriela Vera-Rivera
- Department of Behavioral and Cognitive Neurobiology; Instituto de Neurobiología; Universidad Nacional Autónoma de México (UNAM); Querétaro Mexico
| | - María I. Miranda
- Department of Behavioral and Cognitive Neurobiology; Instituto de Neurobiología; Universidad Nacional Autónoma de México (UNAM); Querétaro Mexico
| | - Isabel Méndez
- Department of Cellular and Molecular Neurobiology; Instituto de Neurobiología; Universidad Nacional Autónoma de México (UNAM); Querétaro Mexico
| | - Mauricio Díaz-Muñoz
- Department of Cellular and Molecular Neurobiology; Instituto de Neurobiología; Universidad Nacional Autónoma de México (UNAM); Querétaro Mexico
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10
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Gedaly R, Galuppo R, Daily MF, Shah M, Maynard E, Chen C, Zhang X, Esser KA, Cohen DA, Evers BM, Jiang J, Spear BT. Targeting the Wnt/β-catenin signaling pathway in liver cancer stem cells and hepatocellular carcinoma cell lines with FH535. PLoS One 2014; 9:e99272. [PMID: 24940873 PMCID: PMC4062395 DOI: 10.1371/journal.pone.0099272] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 05/12/2014] [Indexed: 12/13/2022] Open
Abstract
Activation of the Wnt/β-catenin pathway has been observed in at least 1/3 of hepatocellular carcinomas (HCC), and a significant number of these have mutations in the β-catenin gene. Therefore, effective inhibition of this pathway could provide a novel method to treat HCC. The purposed of this study was to determine whether FH535, which was previously shown to block the β-catenin pathway, could inhibit β-catenin activation of target genes and inhibit proliferation of Liver Cancer Stem Cells (LCSC) and HCC cell lines. Using β-catenin responsive reporter genes, our data indicates that FH535 can inhibit target gene activation by endogenous and exogenously expressed β-catenin, including the constitutively active form of β-catenin that contains a Serine37Alanine mutation. Our data also indicate that proliferation of LCSC and HCC lines is inhibited by FH535 in a dose-dependent manner, and that this correlates with a decrease in the percentage of cells in S phase. Finally, we also show that expression of two well-characterized targets of β-catenin, Cyclin D1 and Survivin, is reduced by FH535. Taken together, this data indicates that FH535 has potential therapeutic value in treatment of liver cancer. Importantly, these results suggest that this therapy may be effective at several levels by targeting both HCC and LCSC.
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Affiliation(s)
- Roberto Gedaly
- Department of Surgery, University of Kentucky, Lexington, Kentucky, United States of America
| | - Roberto Galuppo
- Department of Surgery, University of Kentucky, Lexington, Kentucky, United States of America
| | - Michael F. Daily
- Department of Surgery, University of Kentucky, Lexington, Kentucky, United States of America
| | - Malay Shah
- Department of Surgery, University of Kentucky, Lexington, Kentucky, United States of America
| | - Erin Maynard
- Department of Surgery, University of Kentucky, Lexington, Kentucky, United States of America
| | - Changguo Chen
- Department of Surgery, University of Kentucky, Lexington, Kentucky, United States of America
| | - Xiping Zhang
- Department of Physiology, University of Kentucky, Lexington, Kentucky United States of America
| | - Karyn A. Esser
- Department of Physiology, University of Kentucky, Lexington, Kentucky United States of America
| | - Donald A. Cohen
- Department of Microbiology, Immunology & Molecular Genetics, University of Kentucky, Lexington, Kentucky, United States of America
- Markey Cancer Center, University of Kentucky, Lexington, Kentucky, United States of America
| | - B. Mark Evers
- Markey Cancer Center, University of Kentucky, Lexington, Kentucky, United States of America
| | - Jieyun Jiang
- Department of Microbiology, Immunology & Molecular Genetics, University of Kentucky, Lexington, Kentucky, United States of America
- Markey Cancer Center, University of Kentucky, Lexington, Kentucky, United States of America
| | - Brett T. Spear
- Department of Microbiology, Immunology & Molecular Genetics, University of Kentucky, Lexington, Kentucky, United States of America
- Markey Cancer Center, University of Kentucky, Lexington, Kentucky, United States of America
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The role and clinical implications of microRNAs in hepatocellular carcinoma. SCIENCE CHINA-LIFE SCIENCES 2012; 55:906-19. [PMID: 23108868 DOI: 10.1007/s11427-012-4384-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 09/11/2012] [Indexed: 12/12/2022]
Abstract
Hepatocellular carcinoma (HCC) is common and one of the most aggressive of all human cancers. Recent studies have indicated that miRNAs, a class of small noncoding RNAs that regulate gene expression post-transcriptionally, directly contribute to HCC by targeting many critical regulatory genes. Several miRNAs are involved in hepatitis B or hepatitis C virus replication and virus-induced changes, whereas others participate in multiple intracellular signaling pathways that modulate apoptosis, cell cycle checkpoints, and growth-factor-stimulated responses. When disturbed, these pathways appear to result in malignant transformation and ultimately HCC development. Recently, miRNAs circulating in the blood have acted as possible early diagnostic markers for HCC. These miRNA also could serve as indicators with respect to drug efficacy and be prognostic in HCC patients. Such biomarkers would assist stratification of HCC patients and help direct personalized therapy. Here, we summarize recent advances regarding the role of miRNAs in HCC development and progression. Our expectation is that these and ongoing studies will contribute to the understanding of the multiple roles of these small noncoding RNAs in liver tumorigenesis.
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