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Addison ML, Ranasinghe P, Webb DJ. Novel Pharmacological Approaches in the Treatment of Hypertension: A Focus on RNA-Based Therapeutics. Hypertension 2023; 80:2243-2254. [PMID: 37706295 DOI: 10.1161/hypertensionaha.122.19430] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/15/2023]
Abstract
Hypertension remains the leading cause of cardiovascular disease and premature death globally, affecting half of US adults. A high proportion of hypertensive patients exhibit uncontrolled blood pressure (BP), associated with poor adherence, linked to pill burden and adverse effects. Novel pharmacological strategies are urgently needed to improve BP control. Dysregulation of the renin-angiotensin system increases BP through its primary effector, Ang II (angiotensin II), which results in tissue remodeling and end-organ damage. Silencing liver angiotensinogen (the sole source of Ang II) has been achieved using novel RNA therapeutics, including the antisense oligonucleotide, IONIS-AGT (angiotensinogen)-LRX, and the small-interfering RNA, zilebesiran. Conjugation to N-acetylgalactosamine enables targeted delivery to hepatocytes, where endosomal storage, slow leakage, and small-interfering RNA recycling (for zilebesiran) result in knockdown over several months. Indeed, zilebesiran has an impressive and durable effect on systolic BP, reduced by up to 20 mm Hg and sustained for 6 months after a single administration, likely due to its very effective knockdown of angiotensinogen, without causing acute kidney injury or hyperkalemia. By contrast, IONIS-AGT-LRX caused less knockdown and marginal effects on BP. Future studies should evaluate any loss of efficacy relating to antidrug antibodies, safety issues associated with long-term angiotensinogen suppression, and broader benefits, especially in the context of common comorbidities such as type 2 diabetes and chronic kidney disease.
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Affiliation(s)
- Melisande L Addison
- University/British Heart Foundation Centre for Cardiovascular Science, Queen's Medical Research Institute, College of Medicine & Veterinary Medicine, The University of Edinburgh, Scotland, United Kingdom (M.L.A., P.R., D.J.W.)
| | - Priyanga Ranasinghe
- University/British Heart Foundation Centre for Cardiovascular Science, Queen's Medical Research Institute, College of Medicine & Veterinary Medicine, The University of Edinburgh, Scotland, United Kingdom (M.L.A., P.R., D.J.W.)
- Department of Pharmacology, Faculty of Medicine, University of Colombo, Sri Lanka (P.R.)
| | - David J Webb
- University/British Heart Foundation Centre for Cardiovascular Science, Queen's Medical Research Institute, College of Medicine & Veterinary Medicine, The University of Edinburgh, Scotland, United Kingdom (M.L.A., P.R., D.J.W.)
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Addison ML, Ranasinghe P, Webb DJ. Emerging insights and future prospects for therapeutic application of siRNA targeting angiotensinogen in hypertension. Expert Rev Clin Pharmacol 2023; 16:1025-1033. [PMID: 37897397 DOI: 10.1080/17512433.2023.2277330] [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: 08/18/2023] [Accepted: 10/26/2023] [Indexed: 10/30/2023]
Abstract
INTRODUCTION Hypertension is the main global risk factor for cardiovascular disease. Despite this, less than half of treated hypertensive patients are controlled. One reason for this is nonadherence, a major unmet need in hypertension pharmacotherapy. Small interfering RNA (small interfering ribonucleic acid) therapies inhibit protein translation, and, when linked to N-acetylgalactosamine, allow liver-specific targeting, and durability over several months. Targeted knockdown of hepatic angiotensinogen, the source of all angiotensins, offers a precision medicine approach. AREAS COVERED This article describes the molecular basis for durability over months and the 24-h tonic target inhibition observed after one administration. We present an analysis of the published phase I trials using zilebesiran, a siRNA targeting hepatic angiotensinogen, which reduces blood pressure (BP) by up to 20 mmHg, lasting 24 weeks. Finally, we examine data evaluating reversibility of angiotensinogen knockdown and its relevance to the future clinical utility of zilebesiran. EXPERT OPINION Further studies should assess safety, efficacy, and outcomes in larger, more broadly representative groups. An advantage of zilebesiran is the potential for bi-annual dosing, thereby reducing nonadherence and improving control rates. It may also reduce nighttime BP due to 24-h tonic control. The provision of adherence assessment services will maximize the clinical value of zilebesiran.
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Affiliation(s)
- Melisande L Addison
- University/British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, UK
| | - Priyanga Ranasinghe
- University/British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, UK
- Department of Pharmacology, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka
| | - David J Webb
- University/British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, UK
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3
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Liang SK, Hsu CC, Song HL, Huang YC, Kuo CW, Yao X, Li CC, Yang HC, Hung YL, Chao SY, Wu SC, Tsai FR, Chen JK, Liao WN, Cheng SC, Tsou TC, Wang IC. FOXM1 is required for small cell lung cancer tumorigenesis and associated with poor clinical prognosis. Oncogene 2021; 40:4847-4858. [PMID: 34155349 DOI: 10.1038/s41388-021-01895-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 05/26/2021] [Accepted: 06/04/2021] [Indexed: 12/12/2022]
Abstract
Small cell lung cancer (SCLC) continues to cause poor clinical outcomes due to limited advances in sustained treatments for rapid cancer cell proliferation and progression. The transcriptional factor Forkhead Box M1 (FOXM1) regulates cell proliferation, tumor initiation, and progression in multiple cancer types. However, its biological function and clinical significance in SCLC remain unestablished. Analysis of the Cancer Cell Line Encyclopedia and SCLC datasets in the present study disclosed significant upregulation of FOXM1 mRNA in SCLC cell lines and tissues. Gene set enrichment analysis (GSEA) revealed that FOXM1 is positively correlated with pathways regulating cell proliferation and DNA damage repair, as evident from sensitization of FOXM1-depleted SCLC cells to chemotherapy. Furthermore, Foxm1 knockout inhibited SCLC formation in the Rb1fl/flTrp53fl/flMycLSL/LSL (RPM) mouse model associated with increased levels of neuroendocrine markers, Ascl1 and Cgrp, and decrease in Yap1. Consistently, FOXM1 depletion in NCI-H1688 SCLC cells reduced migration and enhanced apoptosis and sensitivity to cisplatin and etoposide. SCLC with high FOXM1 expression (N = 30, 57.7%) was significantly correlated with advanced clinical stage, extrathoracic metastases, and decrease in overall survival (OS), compared with the low-FOXM1 group (7.90 vs. 12.46 months). Moreover, the high-FOXM1 group showed shorter progression-free survival after standard chemotherapy, compared with the low-FOXM1 group (3.90 vs. 8.69 months). Our collective findings support the utility of FOXM1 as a prognostic biomarker and potential molecular target for SCLC.
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Affiliation(s)
- Sheng-Kai Liang
- Department of Internal Medicine, National Taiwan University Hospital Hsinchu Branch, Hsinchu, 300, Taiwan
- Institute of Biotechnology, National Tsing Hua University, Hsinchu, 300, Taiwan
| | - Chia-Chan Hsu
- Institute of Biotechnology, National Tsing Hua University, Hsinchu, 300, Taiwan
| | - Hsiang-Lin Song
- Department of Pathology, National Taiwan University Hospital Hsinchu Branch, Hsinchu, Taiwan
| | - Yu-Chi Huang
- Institute of Biotechnology, National Tsing Hua University, Hsinchu, 300, Taiwan
- Brain Research Center, National Tsing Hua University, Hsinchu, 300, Taiwan
| | - Chun-Wei Kuo
- Department of Pathology, National Taiwan University Hospital Hsinchu Branch, Hsinchu, Taiwan
| | - Xiang Yao
- Institute of Biotechnology, National Tsing Hua University, Hsinchu, 300, Taiwan
| | - Chien-Cheng Li
- Institute of Biotechnology, National Tsing Hua University, Hsinchu, 300, Taiwan
| | - Hui-Chen Yang
- Department of Internal Medicine, National Taiwan University Hospital Hsinchu Branch, Hsinchu, 300, Taiwan
| | - Yu-Ling Hung
- Institute of Biotechnology, National Tsing Hua University, Hsinchu, 300, Taiwan
- Brain Research Center, National Tsing Hua University, Hsinchu, 300, Taiwan
| | - Sheng-Yang Chao
- Institute of Biotechnology, National Tsing Hua University, Hsinchu, 300, Taiwan
| | - Shun-Chi Wu
- Department of Engineering and System Science, National Tsing Hua University, Hsinchu, 300, Taiwan
| | - Feng-Ren Tsai
- Department of Engineering and System Science, National Tsing Hua University, Hsinchu, 300, Taiwan
| | - Jen-Kun Chen
- Institute of Biomedical Engineering & Nanomedicine, National Health Research Institutes, Zhunan, Miaoli, 350, Taiwan
| | - Wei-Neng Liao
- Institute of Biomedical Engineering & Nanomedicine, National Health Research Institutes, Zhunan, Miaoli, 350, Taiwan
| | - Shih-Chin Cheng
- School of Life Sciences, Xiamen University, Xiamen, Fujian Province, 361102, China
| | - Tsui-Chun Tsou
- National Institute of Environmental Health Sciences, National Health Research Institutes, Zhunan, Miaoli, 350, Taiwan
| | - I-Ching Wang
- Institute of Biotechnology, National Tsing Hua University, Hsinchu, 300, Taiwan.
- Brain Research Center, National Tsing Hua University, Hsinchu, 300, Taiwan.
- Department of Life Sciences, National Tsing Hua University, Hsinchu, 300, Taiwan.
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Haase N, Foster DJ, Cunningham MW, Bercher J, Nguyen T, Shulga-Morskaya S, Milstein S, Shaikh S, Rollins J, Golic M, Herse F, Kräker K, Bendix I, Serdar M, Napieczynska H, Heuser A, Gellhaus A, Thiele K, Wallukat G, Müller DN, LaMarca B, Dechend R. RNA interference therapeutics targeting angiotensinogen ameliorate preeclamptic phenotype in rodent models. J Clin Invest 2021; 130:2928-2942. [PMID: 32338644 DOI: 10.1172/jci99417] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Accepted: 02/13/2020] [Indexed: 01/03/2023] Open
Affiliation(s)
- Nadine Haase
- Max-Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Berlin Germany.,Experimental and Clinical Research Center, Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), Berlin, Germany.,Berlin Institute of Health (BIH), Berlin, Germany
| | | | - Mark W Cunningham
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Julia Bercher
- Experimental and Clinical Research Center, Berlin, Germany
| | - Tuyen Nguyen
- Alnylam Pharmaceuticals, Cambridge, Massachusetts, USA
| | | | | | | | - Jeff Rollins
- Alnylam Pharmaceuticals, Cambridge, Massachusetts, USA
| | - Michaela Golic
- Max-Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Berlin Germany.,Experimental and Clinical Research Center, Berlin, Germany.,Berlin Institute of Health (BIH), Berlin, Germany
| | - Florian Herse
- Max-Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Berlin Germany.,Experimental and Clinical Research Center, Berlin, Germany.,Berlin Institute of Health (BIH), Berlin, Germany
| | - Kristin Kräker
- Max-Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Berlin Germany.,Experimental and Clinical Research Center, Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), Berlin, Germany.,Berlin Institute of Health (BIH), Berlin, Germany
| | - Ivo Bendix
- Department of Pediatrics I Neonatology and Experimental Perinatal Neurosciences and
| | - Meray Serdar
- Department of Pediatrics I Neonatology and Experimental Perinatal Neurosciences and
| | - Hanna Napieczynska
- Max-Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Arnd Heuser
- Max-Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Alexandra Gellhaus
- Department of Gynecology and Obstetrics, University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Kristin Thiele
- Department of Experimental Feto-Maternal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Gerd Wallukat
- Experimental and Clinical Research Center, Berlin, Germany
| | - Dominik N Müller
- Max-Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Berlin Germany.,Experimental and Clinical Research Center, Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), Berlin, Germany.,Berlin Institute of Health (BIH), Berlin, Germany
| | - Babbette LaMarca
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi, USA.,Department of Obstetrics and Gynecology, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Ralf Dechend
- Max-Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Berlin Germany.,Experimental and Clinical Research Center, Berlin, Germany.,Berlin Institute of Health (BIH), Berlin, Germany.,HELIOS-Klinikum, Berlin, Germany.Preeclampsia, with the hallmark features of new-onset hypertension and proteinuria after 20 weeks of gestation, is a major cause of fetal and maternal morbidity and mortality. Studies have demonstrated a role for the renin-angiotensin system (RAS) in its pathogenesis; however, small-molecule RAS blockers are contraindicated because of fetal toxicity. We evaluated whether siRNA targeting maternal hepatic angiotensinogen (Agt, ) could ameliorate symptoms of preeclampsia without adverse placental or fetal effects in 2 rodent models. The first model used a cross of females expressing human Agt, with males expressing human renin, resulting in upregulation of the circulating and uteroplacental RAS. The second model induced ischemia/reperfusion injury and subsequent local and systemic inflammation by surgically reducing placental blood flow mid-gestation (reduced uterine perfusion pressure [RUPP]). These models featured hypertension, proteinuria, and fetal growth restriction, with altered biomarkers. siRNA treatment ameliorated the preeclamptic phenotype in both models, reduced blood pressure, and improved intrauterine growth restriction, with no observed deleterious effects on the fetus. Treatment also improved the angiogenic balance and proteinuria in the transgenic model, and it reduced angiotensin receptor activating antibodies in both. Thus, an RNAi therapeutic targeting Agt, ameliorated the clinical sequelae and improved fetal outcomes in 2 rodent models of preeclampsia
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5
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Forrester SJ, Booz GW, Sigmund CD, Coffman TM, Kawai T, Rizzo V, Scalia R, Eguchi S. Angiotensin II Signal Transduction: An Update on Mechanisms of Physiology and Pathophysiology. Physiol Rev 2018; 98:1627-1738. [PMID: 29873596 DOI: 10.1152/physrev.00038.2017] [Citation(s) in RCA: 585] [Impact Index Per Article: 97.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The renin-angiotensin-aldosterone system plays crucial roles in cardiovascular physiology and pathophysiology. However, many of the signaling mechanisms have been unclear. The angiotensin II (ANG II) type 1 receptor (AT1R) is believed to mediate most functions of ANG II in the system. AT1R utilizes various signal transduction cascades causing hypertension, cardiovascular remodeling, and end organ damage. Moreover, functional cross-talk between AT1R signaling pathways and other signaling pathways have been recognized. Accumulating evidence reveals the complexity of ANG II signal transduction in pathophysiology of the vasculature, heart, kidney, and brain, as well as several pathophysiological features, including inflammation, metabolic dysfunction, and aging. In this review, we provide a comprehensive update of the ANG II receptor signaling events and their functional significances for potential translation into therapeutic strategies. AT1R remains central to the system in mediating physiological and pathophysiological functions of ANG II, and participation of specific signaling pathways becomes much clearer. There are still certain limitations and many controversies, and several noteworthy new concepts require further support. However, it is expected that rigorous translational research of the ANG II signaling pathways including those in large animals and humans will contribute to establishing effective new therapies against various diseases.
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Affiliation(s)
- Steven J Forrester
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University , Philadelphia, Pennsylvania ; Department of Pharmacology and Toxicology, School of Medicine, University of Mississippi Medical Center , Jackson, Mississippi ; Department of Pharmacology, Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City, Iowa ; and Duke-NUS, Singapore and Department of Medicine, Duke University Medical Center , Durham, North Carolina
| | - George W Booz
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University , Philadelphia, Pennsylvania ; Department of Pharmacology and Toxicology, School of Medicine, University of Mississippi Medical Center , Jackson, Mississippi ; Department of Pharmacology, Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City, Iowa ; and Duke-NUS, Singapore and Department of Medicine, Duke University Medical Center , Durham, North Carolina
| | - Curt D Sigmund
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University , Philadelphia, Pennsylvania ; Department of Pharmacology and Toxicology, School of Medicine, University of Mississippi Medical Center , Jackson, Mississippi ; Department of Pharmacology, Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City, Iowa ; and Duke-NUS, Singapore and Department of Medicine, Duke University Medical Center , Durham, North Carolina
| | - Thomas M Coffman
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University , Philadelphia, Pennsylvania ; Department of Pharmacology and Toxicology, School of Medicine, University of Mississippi Medical Center , Jackson, Mississippi ; Department of Pharmacology, Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City, Iowa ; and Duke-NUS, Singapore and Department of Medicine, Duke University Medical Center , Durham, North Carolina
| | - Tatsuo Kawai
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University , Philadelphia, Pennsylvania ; Department of Pharmacology and Toxicology, School of Medicine, University of Mississippi Medical Center , Jackson, Mississippi ; Department of Pharmacology, Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City, Iowa ; and Duke-NUS, Singapore and Department of Medicine, Duke University Medical Center , Durham, North Carolina
| | - Victor Rizzo
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University , Philadelphia, Pennsylvania ; Department of Pharmacology and Toxicology, School of Medicine, University of Mississippi Medical Center , Jackson, Mississippi ; Department of Pharmacology, Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City, Iowa ; and Duke-NUS, Singapore and Department of Medicine, Duke University Medical Center , Durham, North Carolina
| | - Rosario Scalia
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University , Philadelphia, Pennsylvania ; Department of Pharmacology and Toxicology, School of Medicine, University of Mississippi Medical Center , Jackson, Mississippi ; Department of Pharmacology, Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City, Iowa ; and Duke-NUS, Singapore and Department of Medicine, Duke University Medical Center , Durham, North Carolina
| | - Satoru Eguchi
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University , Philadelphia, Pennsylvania ; Department of Pharmacology and Toxicology, School of Medicine, University of Mississippi Medical Center , Jackson, Mississippi ; Department of Pharmacology, Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City, Iowa ; and Duke-NUS, Singapore and Department of Medicine, Duke University Medical Center , Durham, North Carolina
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6
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Padilla-Benavides T, Nasipak BT, Imbalzano AN. Brg1 Controls the Expression of Pax7 to Promote Viability and Proliferation of Mouse Primary Myoblasts. J Cell Physiol 2015; 230:2990-7. [PMID: 26036967 DOI: 10.1002/jcp.25031] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 05/04/2015] [Indexed: 12/29/2022]
Abstract
Brg1 (Brahma-related gene 1) is a catalytic component of the evolutionarily conserved mammalian SWI/SNF ATP-dependent chromatin remodeling enzymes that disrupt histone-DNA contacts on the nucleosome. While the requirement for the SWI/SNF enzymes in cell differentiation has been extensively studied, its role in precursor cell proliferation and survival is not as well defined. Muscle satellite cells constitute the stem cell pool that sustains and regenerates myofibers in adult skeletal muscle. Here, we show that deletion of Brg1 in primary mouse myoblasts derived from muscle satellite cells cultured ex vivo leads to a cell proliferation defect and apoptosis. We determined that Brg1 regulates cell proliferation and survival by controlling chromatin remodeling and activating transcription at the Pax7 promoter, which is expressed during somite development and is required for controlling viability of the satellite cell population. Reintroduction of catalytically active Brg1 or of Pax7 into Brg1-deficient satellite cells rescued the apoptotic phenotype and restored proliferation. These data demonstrate that Brg1 functions as a positive regulator for cellular proliferation and survival of primary myoblasts. Therefore, the regulation of gene expression through Brg1-mediated chromatin remodeling is critical not just for skeletal muscle differentiation but for maintaining the myoblast population as well.
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Affiliation(s)
- Teresita Padilla-Benavides
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Brian T Nasipak
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Anthony N Imbalzano
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts
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7
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Nasipak BT, Padilla-Benavides T, Green KM, Leszyk JD, Mao W, Konda S, Sif S, Shaffer SA, Ohkawa Y, Imbalzano AN. Opposing calcium-dependent signalling pathways control skeletal muscle differentiation by regulating a chromatin remodelling enzyme. Nat Commun 2015; 6:7441. [PMID: 26081415 PMCID: PMC4530624 DOI: 10.1038/ncomms8441] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 05/06/2015] [Indexed: 01/03/2023] Open
Abstract
Calcium signaling is important for differentiation-dependent gene expression, but is also involved in other cellular functions. Therefore mechanisms must exist to distinguish calcium signaling relevant to differentiation. Calcineurin is a calcium-regulated phosphatase that is required for myogenic gene expression and skeletal muscle differentiation. Here, we demonstrate that inhibition of calcineurin blocks chromatin remodeling and that the Brg1 ATPase of the SWI/SNF chromatin remodeling enzyme, which is required for the activation of myogenic gene expression, is a calcineurin substrate. Furthermore, we identify the calcium-regulated classical protein kinase C beta (PKCβ) as a repressor of myogenesis and as the enzyme that opposes calcineurin function. Replacement of endogenous Brg1 with a phosphomimetic mutant in primary myoblasts inhibits myogenesis, while replacement with a non-phosphorylatable mutant allows myogenesis despite inhibition of calcineurin signaling, demonstrating the functionality of calcineurin/PKC modified residues. Thus the Brg1 chromatin remodeling enzyme integrates two antagonistic calcium-dependent signaling pathways that control myogenic differentiation.
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Affiliation(s)
- Brian T Nasipak
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| | - Teresita Padilla-Benavides
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| | - Karin M Green
- Proteomics and Mass Spectrometry Facility, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| | - John D Leszyk
- Proteomics and Mass Spectrometry Facility, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| | - Wenjie Mao
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| | - Silvana Konda
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| | - Saïd Sif
- Department of Internal Medicine, College of Medicine, Ohio State University, Columbus, Ohio 43210, USA.,Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, PO Box 2713, Doha, Qatar
| | - Scott A Shaffer
- Proteomics and Mass Spectrometry Facility, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| | - Yasuyuki Ohkawa
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA.,Department Advanced Medical Initiatives, JST-CREST, Faculty of Medicine, Kyushu University, 3-1-1 Maidashi Fukuoka 812-8582, Japan
| | - Anthony N Imbalzano
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
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8
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Lemaigre FP. Determining the fate of hepatic cells by lineage tracing: facts and pitfalls. Hepatology 2015; 61:2100-3. [PMID: 25503476 DOI: 10.1002/hep.27659] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 12/10/2014] [Indexed: 12/19/2022]
Abstract
Slow renewal of the epithelial cells by proliferation ensures homeostasis of the liver, but extensive proliferation may occur upon injury. When proliferation is impaired, transdifferentiation of mature cells or differentiation of stem cells allows production of new hepatocytes and cholangiocytes. While lineage tracings using cyclization recombinase (Cre) recombinase-mediated cell labeling represent the gold standard for defining cell fate, there are more variables than was initially realized. This led to controversies about the capacity of liver cells to switch their fate. Here, I review how cells are traced in the liver and highlight the experimental pitfalls that may cause misinterpretations and controversies.
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9
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Sharma S, Zhu J. Immunologic applications of conditional gene modification technology in the mouse. ACTA ACUST UNITED AC 2014; 105:10.34.1-10.34.13. [PMID: 24700321 DOI: 10.1002/0471142735.im1034s105] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Since the success of homologous recombination in altering mouse genome and the discovery of Cre-loxP system, the combination of these two breakthroughs has created important applications for studying the immune system in the mouse. Here, we briefly summarize the general principles of this technology and its applications in studying immune cell development and responses; such implications include conditional gene knockout and inducible and/or tissue-specific gene over-expression, as well as lineage fate mapping. We then discuss the pros and cons of a few commonly used Cre-expressing mouse lines for studying lymphocyte development and functions. We also raise several general issues, such as efficiency of gene deletion, leaky activity of Cre, and Cre toxicity, all of which may have profound impacts on data interpretation. Finally, we selectively list some useful links to the Web sites as valuable mouse resources.
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Affiliation(s)
- Suveena Sharma
- Molecular and Cellular Immunoregulation Unit, Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Jinfang Zhu
- Molecular and Cellular Immunoregulation Unit, Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
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10
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Mohseni M, Sun J, Lau A, Curtis S, Goldsmith J, Fox VL, Wei C, Frazier M, Samson O, Wong KK, Wong KK, Kim C, Camargo FD. A genetic screen identifies an LKB1-MARK signalling axis controlling the Hippo-YAP pathway. Nat Cell Biol 2013; 16:108-17. [PMID: 24362629 DOI: 10.1038/ncb2884] [Citation(s) in RCA: 224] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 10/28/2013] [Indexed: 12/11/2022]
Abstract
The Hippo-YAP pathway is an emerging signalling cascade involved in the regulation of stem cell activity and organ size. To identify components of this pathway, we performed an RNAi-based kinome screen in human cells. Our screen identified several kinases not previously associated with Hippo signalling that control multiple cellular processes. One of the hits, LKB1, is a common tumour suppressor whose mechanism of action is only partially understood. We demonstrate that LKB1 acts through its substrates of the microtubule affinity-regulating kinase family to regulate the localization of the polarity determinant Scribble and the activity of the core Hippo kinases. Our data also indicate that YAP is functionally important for the tumour suppressive effects of LKB1. Our results identify a signalling axis that links YAP activation with LKB1 mutations, and have implications for the treatment of LKB1-mutant human malignancies. In addition, our findings provide insight into upstream signals of the Hippo-YAP signalling cascade.
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Affiliation(s)
- Morvarid Mohseni
- 1] Stem Cell Program, Boston Children's Hospital, Boston, Massachusetts 02115, USA [2] Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts 02138, USA [3] Harvard Stem Cell Institute, Cambridge, Massachusetts 02138, USA
| | - Jianlong Sun
- 1] Stem Cell Program, Boston Children's Hospital, Boston, Massachusetts 02115, USA [2] Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts 02138, USA [3] Harvard Stem Cell Institute, Cambridge, Massachusetts 02138, USA
| | - Allison Lau
- 1] Stem Cell Program, Boston Children's Hospital, Boston, Massachusetts 02115, USA [2] Harvard Stem Cell Institute, Cambridge, Massachusetts 02138, USA
| | - Stephen Curtis
- 1] Stem Cell Program, Boston Children's Hospital, Boston, Massachusetts 02115, USA [2] Harvard Stem Cell Institute, Cambridge, Massachusetts 02138, USA [3] Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Jeffrey Goldsmith
- Center for Pediatric Polyposis, Boston Children's Hospital, Boston, Massachusetts 02115, USA
| | - Victor L Fox
- Division of Gastroenterology and Nutrition, Boston Children's Hospital, Boston, Massachusetts 02115, USA
| | - Chongjuan Wei
- Department of Epidemiology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Marsha Frazier
- Department of Epidemiology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Owen Samson
- Wnt Signaling and Colorectal Cancer Group, The Beatson Institute for Cancer Research, Cancer Research UK, Glasgow G61 1BD, UK
| | | | - Kwok-Kim Wong
- 1] Genetics Division, Department of Medicine Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA [2] Ludwig Center at Dana-Farber/Harvard Cancer Center, Boston, Massachusetts 02115, USA
| | - Carla Kim
- 1] Stem Cell Program, Boston Children's Hospital, Boston, Massachusetts 02115, USA [2] Harvard Stem Cell Institute, Cambridge, Massachusetts 02138, USA [3] Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Fernando D Camargo
- 1] Stem Cell Program, Boston Children's Hospital, Boston, Massachusetts 02115, USA [2] Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts 02138, USA [3] Harvard Stem Cell Institute, Cambridge, Massachusetts 02138, USA
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11
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Baba Y, Nakano M, Yamada Y, Saito I, Kanegae Y. Practical Range of Effective Dose for Cre Recombinase-Expressing Recombinant Adenovirus without Cell Toxicity in Mammalian Cells. Microbiol Immunol 2013; 49:559-70. [PMID: 15965304 DOI: 10.1111/j.1348-0421.2005.tb03753.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The site-specific recombinase Cre is valuable for regulation of gene expression not only in vitro but also in vivo. We previously reported that replication-deficient recombinant adenovirus (rAd) expressing Cre can mediate efficient and strict regulation in 100% of cultured cells. Recently, the constitutive-expression of Cre using retrovirus or lentivirus vector reportedly inhibited cell-growth, but the effect of transient Cre expression have not yet been examined. Here we showed that an excess amount of Cre produced from Cre-expressing rAd caused a deleterious effect in cells even when Cre was transiently expressed. We used three rAds carrying promoters with different activities: the SV40 early promoter (AxSVENCre), the SR alpha promoter (AxSRCre) and the CAG promoter (AxCANCre). Cell toxicity was clearly caused by Cre itself and was distinguishable from that caused by rAd virions when the cytopathic effects of these rAds were compared with that of a control virus lacking the Cre expression unit. Cre toxicity was strongly correlated with the expression level of Cre. Importantly, AxSRCre and AxCANCre gave a 60-fold range of effective MOIs ("effective range") sufficient for gene activation without causing cell toxicity from either the rAd particles or Cre itself, while AxSVENCre failed to give such a range because the expression level of Cre was too low. When Cre was tagged with a nuclear localization signal (NLS), not only its activity but also Cre toxicity was increased fourfold, and the effective range was unchanged. Therefore, AxSRNCre might be more useful to control cell toxicity from the rAd virions than AxSRCre. Cre-induced cell toxicity can be avoided by pre-examining the "effective range" using the purpose cell lines before starting experiments utilizing the experiment of Cre-expressing rAd.
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Affiliation(s)
- Yasuko Baba
- Laboratory of Molecular Genetics, Institute of Medical Science, University of Tokyo, Japan
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12
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Vitucci M, Karpinich NO, Bash RE, Werneke AM, Schmid RS, White KK, McNeill RS, Huff B, Wang S, Van Dyke T, Miller CR. Cooperativity between MAPK and PI3K signaling activation is required for glioblastoma pathogenesis. Neuro Oncol 2013; 15:1317-29. [PMID: 23814263 DOI: 10.1093/neuonc/not084] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Glioblastoma (GBM) genomes feature recurrent genetic alterations that dysregulate core intracellular signaling pathways, including the G1/S cell cycle checkpoint and the MAPK and PI3K effector arms of receptor tyrosine kinase (RTK) signaling. Elucidation of the phenotypic consequences of activated RTK effectors is required for the design of effective therapeutic and diagnostic strategies. METHODS Genetically defined, G1/S checkpoint-defective cortical murine astrocytes with constitutively active Kras and/or Pten deletion mutations were used to systematically investigate the individual and combined roles of these 2 RTK signaling effectors in phenotypic hallmarks of glioblastoma pathogenesis, including growth, migration, and invasion in vitro. A novel syngeneic orthotopic allograft model system was used to examine in vivo tumorigenesis. RESULTS Constitutively active Kras and/or Pten deletion mutations activated both MAPK and PI3K signaling. Their combination led to maximal growth, migration, and invasion of G1/S-defective astrocytes in vitro and produced progenitor-like transcriptomal profiles that mimic human proneural GBM. Activation of both RTK effector arms was required for in vivo tumorigenesis and produced highly invasive, proneural-like GBM. CONCLUSIONS These results suggest that cortical astrocytes can be transformed into GBM and that combined dysregulation of MAPK and PI3K signaling revert G1/S-defective astrocytes to a primitive gene expression state. This genetically-defined, immunocompetent model of proneural GBM will be useful for preclinical development of MAPK/PI3K-targeted, subtype-specific therapies.
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Affiliation(s)
- Mark Vitucci
- Corresponding Author: C. Ryan Miller, MD, PhD, University of North Carolina School of Medicine, 6109B Neurosciences Research Building, Campus Box 7250, Chapel Hill, NC 27599-7250.
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13
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GFAP-Cre-mediated transgenic activation of Bmi1 results in pituitary tumors. PLoS One 2012; 7:e35943. [PMID: 22574128 PMCID: PMC3344841 DOI: 10.1371/journal.pone.0035943] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 03/28/2012] [Indexed: 01/12/2023] Open
Abstract
Bmi1 is a member of the polycomb repressive complex 1 and plays different roles during embryonic development, depending on the developmental context. Bmi1 over expression is observed in many types of cancer, including tumors of astroglial and neural origin. Although genetic depletion of Bmi1 has been described to result in tumor inhibitory effects partly through INK4A/Arf mediated senescence and apoptosis and also through INK4A/Arf independent effects, it has not been proven that Bmi1 can be causally involved in the formation of these tumors. To see whether this is the case, we developed two conditional Bmi1 transgenic models that were crossed with GFAP-Cre mice to activate transgenic expression in neural and glial lineages. We show here that these mice generate intermediate and anterior lobe pituitary tumors that are positive for ACTH and beta-endorphin. Combined transgenic expression of Bmi1 together with conditional loss of Rb resulted in pituitary tumors but was insufficient to induce medulloblastoma therefore indicating that the oncogenic function of Bmi1 depends on regulation of p16INK4A/Rb rather than on regulation of p19ARF/p53. Human pituitary adenomas show Bmi1 overexpression in over 50% of the cases, which indicates that Bmi1 could be causally involved in formation of these tumors similarly as in our mouse model.
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14
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Grobe JL, Rahmouni K, Liu X, Sigmund CD. Metabolic rate regulation by the renin-angiotensin system: brain vs. body. Pflugers Arch 2012; 465:167-75. [PMID: 22491893 DOI: 10.1007/s00424-012-1096-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Accepted: 03/02/2012] [Indexed: 01/28/2023]
Abstract
Substantial evidence supports a role for the renin-angiotensin system (RAS) in the regulation of metabolic function, but an apparent paradox exists where genetic or pharmacological inhibition of the RAS occasionally has similar physiological effects as chronic angiotensin infusion. Similarly, while RAS targeting in animal models has robust metabolic consequences, effects in humans are more subtle. Here, we review the data supporting a role for the RAS in metabolic rate regulation and propose a model where the local brain RAS works in opposition to the peripheral RAS, thus helping to explain the paradoxically similar effects of RAS supplementation and inhibition. Selectively modulating the peripheral RAS or brain RAS may thus provide a more effective treatment paradigm for obesity and obesity-related disorders.
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Affiliation(s)
- Justin L Grobe
- Department of Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 3181 MERF, 375 Newton Rd., Iowa City, IA 52242, USA
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15
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Stec DE, Drummond HA, Gousette MU, Storm MV, Abraham NG, Csongradi E. Expression of heme oxygenase-1 in thick ascending loop of henle attenuates angiotensin II-dependent hypertension. J Am Soc Nephrol 2012; 23:834-41. [PMID: 22323644 DOI: 10.1681/asn.2011050455] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Kidney-specific induction of heme oxygenase-1 (HO-1) attenuates the development of angiotensin II (Ang II) -dependent hypertension, but the relative contribution of vascular versus tubular induction of HO-1 is unknown. To determine the specific contribution of thick ascending loop of Henle (TALH) -derived HO-1, we generated a transgenic mouse in which the uromodulin promoter controlled expression of human HO-1. Quantitative RT-PCR and confocal microscopy confirmed successful localization of the HO-1 transgene to TALH tubule segments. Medullary HO activity, but not cortical HO activity, was significantly higher in transgenic mice than control mice. Enhanced TALH HO-1 attenuated the hypertension induced by Ang II delivered by an osmotic minipump for 10 days (139 ± 3 versus 153 ±2 mmHg in the transgenic and control mice, respectively; P<0.05). The lower blood pressure in transgenic mice associated with a 60% decrease in medullary NKCC2 transporter expression determined by Western blot. Transgenic mice also exhibited a 36% decrease in ouabain-sensitive sodium reabsorption and a significantly attenuated response to furosemide in isolated TALH segments. In summary, these results show that increased levels of HO-1 in the TALH can lower blood pressure by a mechanism that may include alterations in NKCC2-dependent sodium reabsorption.
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Affiliation(s)
- David E Stec
- Department of Physiology and Biophysics, Center for Excellence in Cardiovascular-Renal Research, University of Mississippi Medical Center, Jackson, 39216, USA.
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16
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Grobe JL, Rahmouni K. Editorial focus: A fat contribution to RAS activation and blood pressure control: evidence from angiotensinogen conditional null mice. Focus on: "Adipocyte-specific deficiency of angiotensinogen decreases plasma angiotensinogen concentration and systolic blood pressure in mice.". Am J Physiol Regul Integr Comp Physiol 2012; 302:R242-3. [PMID: 22071163 DOI: 10.1152/ajpregu.00608.2011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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17
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Sigmund CD. Divergent mechanism regulating fluid intake and metabolism by the brain renin-angiotensin system. Am J Physiol Regul Integr Comp Physiol 2011; 302:R313-20. [PMID: 22049229 DOI: 10.1152/ajpregu.00575.2011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The purpose of this review is two-fold. First, I will highlight recent advances in our understanding of the mechanisms regulating angiotensin II (ANG II) synthesis in the brain, focusing on evidence that renin is expressed in the brain and is expressed in two forms: a secreted form, which may catalyze extracellular ANG I generation from glial or neuronal angiotensinogen (AGT), and an intracellular form, which may generate intracellular ANG in neurons that may act as a neurotransmitter. Second, I will discuss recent studies that advance the concept that the renin-angiotensin system (RAS) in the brain not only is a potent regulator of blood pressure and fluid intake but may also regulate metabolism. The efferent pathways regulating the blood pressure/dipsogenic effects and the metabolic effects of elevated central RAS activity appear different, with the former being dependent upon the hypothalamic-pituitary-adrenal axis, and the latter being dependent upon an interaction between the brain and the systemic (or adipose) RAS.
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Affiliation(s)
- Curt D Sigmund
- Department of Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, 52242, USA.
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18
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Maund SL, Barclay WW, Hover LD, Axanova LS, Sui G, Hipp JD, Fleet JC, Thorburn A, Cramer SD. Interleukin-1α mediates the antiproliferative effects of 1,25-dihydroxyvitamin D3 in prostate progenitor/stem cells. Cancer Res 2011; 71:5276-86. [PMID: 21653679 DOI: 10.1158/0008-5472.can-10-2160] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Vitamin D(3) is a promising preventative and therapeutic agent for prostate cancer, but its implementation is hampered by a lack of understanding about its mechanism of action. Upon treatment with 1α,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3), vitamin D(3)], the metabolically active form of vitamin D(3), adult prostate progenitor/stem cells (PrP/SC) undergo cell-cycle arrest, senescence, and differentiation to an androgen receptor-positive luminal epithelial cell fate. Microarray analyses of control- and vitamin D(3)-treated PrP/SCs revealed global gene expression signatures consistent with induction of differentiation. Interestingly, one of the most highly upregulated genes by vitamin D(3) was the proinflammatory cytokine interleukin-1α (IL-1α). Systems biology analyses supported a central role for IL-1α in the vitamin D(3) response in PrP/SCs. siRNA-mediated knockdown of IL-1α abrogated vitamin D(3)-induced growth suppression, establishing a requirement for IL-1α in the antiproliferative effects of vitamin D(3) in PrP/SCs. These studies establish a system to study the molecular profile of PrP/SC differentiation, proliferation, and senescence, and they point to an important new role for IL-1α in vitamin D(3) signaling in PrP/SCs.
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Affiliation(s)
- Sophia L Maund
- Department of Cancer Biology, Wake Forest University School of Medicine, Winston-Salem, NC, USA
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19
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Adaptation to moderate hypoxia protects cortical neurons against ischemia-reperfusion injury and excitotoxicity independently of HIF-1α. Exp Neurol 2011; 230:302-10. [PMID: 21619879 DOI: 10.1016/j.expneurol.2011.05.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Revised: 04/19/2011] [Accepted: 05/10/2011] [Indexed: 11/20/2022]
Abstract
Continuous exposure of cultured cortical neurons to moderate hypoxia (1% O(2)) elevates cellular accumulation of hypoxia-inducible factor-1α (HIF-1α) and improves basal survival of cultured cortical neurons. We examined the effects of adaptation to moderate hypoxia on the vulnerability of cultured neurons to the acute injury of simulated ischemia-reperfusion. Cortical neurons cultured continuously in 1% O(2) were markedly protected against simulated ischemia-reperfusion, with protection persisting through 72h after ischemia. Neurons from 1% O(2) conditions were also highly resistant to glutamate-induced NMDA receptor-dependent excitotoxic injury, despite expression of NMDA receptors at levels not significantly changed from controls. Inhibition of prolyl hydroxylase, mimicking cellular signaling effects of hypoxia including HIF-1α stabilization, also protected neurons against simulated ischemia-reperfusion injury. Nevertheless, genetic deletion of HIF-1α expression did not diminish the protection of neurons adapted to 1% O(2) from excitotoxicity or ischemia-reperfusion injury, nor did it prevent the protective effect of prolyl hydroxylase inhibition. We conclude that chronic exposure to moderate hypoxia, through HIF-1α-independent mechanisms, produces strong protective effects against excitotoxic and ischemia-reperfusion related injury.
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20
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Wu C, Lu H, Cassis LA, Daugherty A. Molecular and Pathophysiological Features of Angiotensinogen: A Mini Review. ACTA ACUST UNITED AC 2011; 4:183-190. [PMID: 22389749 DOI: 10.7156/v4i4p183] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The renin-angiotensin system is an essential regulatory system for blood pressure and fluid homeostasis. Angiotensinogen is the only known precursor of all the peptides generated in this system. While many of the basic understandings of angiotensinogen have come from research efforts to define its role in blood pressure regulation, novel pathophysiological functions of angiotensinogen have been discovered in the last two decades including kidney developmental abnormalities, atherosclerosis, and obesity. Despite the impressive advance in the understanding of angiotensinogen gene structure and protein functions, some fundamental questions remain unanswered. In this short review, we provide contemporary insights into the molecular characteristics of angiotensinogen and its pathophysiological features. In light of the recent progress, we emphasize some newly recognized functional features of angiotensinogen other than its regulation on blood pressure.
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Affiliation(s)
- Congqing Wu
- Saha Cardiovascular Research Center, University of Kentucky, Lexington, Kentucky, USA
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21
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Bonilla SF, Melin-Aldana H, Whitington PF. Relationship of proximal renal tubular dysgenesis and fetal liver injury in neonatal hemochromatosis. Pediatr Res 2010; 67:188-93. [PMID: 19809376 DOI: 10.1203/pdr.0b013e3181c2df69] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Renal tubular dysgenesis has been reported in isolated cases of neonatal hemochromatosis (NH). We hypothesized that fetal liver injury in NH impairs proximal renal tubular development via impaired hepatic angiotensinogen (AGT) elaboration. Morphometric analyses were performed of postmortem liver and kidney sections of cases of proven NH and postconception age-matched controls for renal proximal tubule density, hepatocyte mass, and hepatic AGT expression. Proximal tubule density was markedly reduced in NH cases, although they showed a spectrum from mild to severe paucity. Hepatic AGT expression was markedly reduced in NH cases and correlated closely with reduced hepatocyte mass. A linear relationship was established between hepatic AGT expression and the degree of renal tubular dysgenesis suggesting that there is a relationship between them. Our results demonstrate that there is a spectrum of kidney pathology in patients with NH including a large proportion of cases with severe proximal tubular dysgenesis. Hepatic synthetic failure resulting in insufficient production of AGT to support renal tubular development is the likely mechanism of kidney disease in NH.
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Affiliation(s)
- Silvana F Bonilla
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60614, USA
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22
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Oas RG, Xiao K, Summers S, Wittich KB, Chiasson CM, Martin WD, Grossniklaus HE, Vincent PA, Reynolds AB, Kowalczyk AP. p120-Catenin is required for mouse vascular development. Circ Res 2010; 106:941-51. [PMID: 20110533 DOI: 10.1161/circresaha.109.207753] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
RATIONALE p120-catenin (p120) is an armadillo family protein that binds to the cytoplasmic domain of classical cadherins and prevents cadherin endocytosis. The role of p120 in vascular development is unknown. OBJECTIVE The purpose of this study is to examine the role of p120 in mammalian vascular development by generating a conditionally mutant mouse lacking endothelial p120 and determining the effects of the knockout on vasculogenesis, angiogenic remodeling, and the regulation of endothelial cadherin levels. METHODS AND RESULTS A conditional Cre/loxP gene deletion strategy was used to ablate p120 expression, using the Tie2 promoter to drive endothelial Cre recombinase expression. Mice lacking endothelial p120 died embryonically beginning at embryonic day 11.5. Major blood vessels appeared normal at embryonic day 9.5. However, both embryonic and extraembryonic vasculature of mutant animals were disorganized and displayed decreased microvascular density by embryonic day 11.5. Importantly, both vascular endothelial cadherin and N-cadherin levels were significantly reduced in vessels lacking p120. This decrease in cadherin expression was accompanied by reduced pericyte recruitment and hemorrhaging. Furthermore, p120-null cultured endothelial cells exhibited proliferation defects that could be rescued by exogenous expression of vascular endothelial cadherin. CONCLUSIONS These findings reveal a fundamental role for p120 in regulating endothelial cadherin levels during vascular development, as well as microvascular patterning, vessel integrity, and endothelial cell proliferation. Loss of endothelial p120 results in lethality attributable to decreased microvascular density and hemorrhages.
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Affiliation(s)
- Rebecca G Oas
- Department of Cell Biology, 615 Michael St, Room 465, Atlanta, GA 30322, USA
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23
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Kim I, Ding T, Fu Y, Li C, Cui L, Li A, Lian P, Liang D, Wang DW, Guo C, Ma J, Zhao P, Coffey RJ, Zhan Q, Wu G. Conditional mutation of Pkd2 causes cystogenesis and upregulates beta-catenin. J Am Soc Nephrol 2009; 20:2556-69. [PMID: 19939939 DOI: 10.1681/asn.2009030271] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Loss of polycystin-2 (PC2) in mice (Pkd2(-/-)) results in total body edema, focal hemorrhage, structural cardiac defects, abnormal left-right axis, hepatorenal and pancreatic cysts, and embryonic lethality. The molecular mechanisms by which loss of PC2 leads to these phenotypes remain unknown. We generated a model to allow targeted Pkd2 inactivation using the Cre-loxP system. Global inactivation of Pkd2 produced a phenotype identical to Pkd2(-/-) mice with undetectable PC2 protein and perinatal lethality. Using various Cre mouse lines, we found that kidney, pancreas, or time-specific deletion of Pkd2 led to cyst formation. In addition, we developed an immortalized renal collecting duct cell line with inactive Pkd2; these cells had aberrant cell-cell contact, ciliogenesis, and tubulomorphogenesis. They also significantly upregulated beta-catenin, axin2, and cMyc. Our results suggest that loss of PC2 disrupts normal behavior of renal epithelial cells through dysregulation of beta-catenin-dependent signaling, revealing a potential role for this signaling pathway in PC2-associated ADPKD.
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Affiliation(s)
- Ingyu Kim
- Division of Genetic Medicine, Department of Medicine and Cell and Developmental Biology, Vanderbilt University, 2215 Garland Avenue, Nashville, TN 37232, USA
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24
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Chopra AR, Louet JF, Saha P, An J, DeMayo F, Xu J, York B, Karpen S, Finegold M, Moore D, Chan L, Newgard CB, O'Malley BW. Absence of the SRC-2 coactivator results in a glycogenopathy resembling Von Gierke's disease. Science 2008; 322:1395-9. [PMID: 19039140 PMCID: PMC2668604 DOI: 10.1126/science.1164847] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Hepatic glucose production is critical for basal brain function and survival when dietary glucose is unavailable. Glucose-6-phosphatase (G6Pase) is an essential, rate-limiting enzyme that serves as a terminal gatekeeper for hepatic glucose release into the plasma. Mutations in G6Pase result in Von Gierke's disease (glycogen storage disease-1a), a potentially fatal genetic disorder. We have identified the transcriptional coactivator SRC-2 as a regulator of fasting hepatic glucose release, a function that SRC-2 performs by controlling the expression of hepatic G6Pase. SRC-2 modulates G6Pase expression directly by acting as a coactivator with the orphan nuclear receptor RORalpha. In addition, SRC-2 ablation, in both a whole-body and liver-specific manner, resulted in a Von Gierke's disease phenotype in mice. Our results position SRC-2 as a critical regulator of mammalian glucose production.
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Affiliation(s)
- Atul R. Chopra
- Department of Molecular and Cellular Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
| | - Jean-Francois Louet
- Department of Molecular and Cellular Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
| | - Pradip Saha
- Department of Molecular and Cellular Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
| | - Jie An
- Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27710, USA
| | - Franco DeMayo
- Department of Molecular and Cellular Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
| | - Jianming Xu
- Department of Molecular and Cellular Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
| | - Brian York
- Department of Molecular and Cellular Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
| | - Saul Karpen
- Department of Molecular and Cellular Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Milton Finegold
- Department of Pathology, Baylor College of Medicine, Houston, TX 77030, USA
| | - David Moore
- Department of Molecular and Cellular Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
| | - Lawrence Chan
- Department of Molecular and Cellular Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
| | - Christopher B. Newgard
- Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27710, USA
| | - Bert W. O'Malley
- Department of Molecular and Cellular Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
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25
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Grobe JL, Xu D, Sigmund CD. An intracellular renin-angiotensin system in neurons: fact, hypothesis, or fantasy. Physiology (Bethesda) 2008; 23:187-93. [PMID: 18697992 DOI: 10.1152/physiol.00002.2008] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The renin-angiotensin system in the brain acts to regulate a number of physiological processes. Evidence suggests that angiotensin peptides may act as neurotransmitters, although their biosynthetic pathways are poorly understood. We review evidence for neuronal production of angiotensin peptides and hypothesize that angiotensin may be synthesized intracellularly in neurons.
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Affiliation(s)
- Justin L Grobe
- Department of Internal Medicine, Center on Functional Genomics of Hypertension, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
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26
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Dickson ME, Tian X, Liu X, Davis DR, Sigmund CD. Upstream stimulatory factor is required for human angiotensinogen expression and differential regulation by the A-20C polymorphism. Circ Res 2008; 103:940-7. [PMID: 18802024 DOI: 10.1161/circresaha.108.180653] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Among naturally occurring polymorphisms in the 5' flanking region of the human angiotensinogen (AGT) gene, the -20 and -217 polymorphisms have the strongest effects on AGT regulation in AGT-expressing cells derived from liver, kidney, brain, and fat. These polymorphisms may affect allele-specific transcription factor binding, and the high-expressing alleles are both relatively common. We show herein that the -20C allele has higher transcriptional activity than -20A, and the -20A allele confers no additional transactivation potential beyond that of a mutated vector. Gel-shift assays show that upstream stimulatory factor (USF)1 and USF2 preferentially bind the -20C allele, whereas the -20A allele retains a low affinity USF binding site. Plasmid immunoprecipitation assays confirmed preferential association of USF1 with the -20C allele in transfected HepG2 cells. Chromatin immunoprecipitation confirmed that USF1 binds to the endogenous AGT -20C allele in CCF cells, the only cell line tested that carries the -20C allele, and to the human AGT promoter in liver and adipose tissue from transgenic mice. Transduction of AGT-expressing cells with short hairpin RNAs specifically targeting USF1 or USF2, resulted in cell- and allele-specific attenuation of AGT promoter activity. In vivo, knockdown of USF expression in the liver of transgenic mice expressing the -20C allele of AGT resulted in lower AGT expression, a decrease in circulating human AGT protein but no change in expression of GAPDH or hepatocyte nuclear factor-4alpha. We conclude that USF1 functionally and differentially regulates AGT expression via the -20 polymorphism and that the differential expression exhibited by -20 can be accounted for by differential association with USF1.
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Affiliation(s)
- Matthew E Dickson
- Genetics and Medical Scientist Training Programs, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
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Ho KJ, Bass CE, Kroemer AHK, Ma C, Terwilliger E, Karp SJ. Optimized adeno-associated virus 8 produces hepatocyte-specific Cre-mediated recombination without toxicity or affecting liver regeneration. Am J Physiol Gastrointest Liver Physiol 2008; 295:G412-9. [PMID: 18535290 PMCID: PMC2519860 DOI: 10.1152/ajpgi.00590.2007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
UNLABELLED Engineering viral vectors to produce liver-specific protein expression may help advance understanding of hepatic regeneration and disease states. In addition to introducing genes of interest to the liver, these vectors can be adapted for gene deletion when designed to express Cre recombinase. The ability to use this system requires high, liver-restricted expression, low toxicity, and no effect on the process of interest. We developed an adeno-associated virus 8 (AAV8) with a codon-optimized Cre recombinase under a hepatocyte-specific major urinary protein (MUP) promoter (MUP-iCre-AAV8) that fulfills these requirements. A single intravenous injection of ROSA26R reporter mice, which express lacZ after Cre-mediated recombination, demonstrated homogeneous beta-galactosidase expression limited to hepatocytes after only 7 days. Cre protein expression remained strong for at least 31 days. Serum liver function tests and histology demonstrated minimal liver toxicity. The presence of MUP-iCre-AAV8 did not affect hepatocyte proliferation after partial hepatectomy as measured by Ki67 staining. CONCLUSION AAV8 with the MUP promoter, by virtue of its lack of hepatic toxicity or effect on liver regeneration, may be an efficient alternative to complex transgenic methodologies for studies of the mouse liver.
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Affiliation(s)
- Karen J. Ho
- Departments of Surgery and Medicine, Beth Israel Deaconess Medical Center, Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts
| | - Caroline E. Bass
- Departments of Surgery and Medicine, Beth Israel Deaconess Medical Center, Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts
| | - Alexander H. K. Kroemer
- Departments of Surgery and Medicine, Beth Israel Deaconess Medical Center, Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts
| | - Chunyan Ma
- Departments of Surgery and Medicine, Beth Israel Deaconess Medical Center, Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts
| | - Ernest Terwilliger
- Departments of Surgery and Medicine, Beth Israel Deaconess Medical Center, Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts
| | - Seth J. Karp
- Departments of Surgery and Medicine, Beth Israel Deaconess Medical Center, Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts
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Phillips MI, de Oliveira EM. Brain renin angiotensin in disease. J Mol Med (Berl) 2008; 86:715-22. [PMID: 18385968 PMCID: PMC7095973 DOI: 10.1007/s00109-008-0331-5] [Citation(s) in RCA: 154] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Revised: 02/20/2008] [Accepted: 02/21/2008] [Indexed: 02/06/2023]
Abstract
A brain renin angiotensin system (RAS) and its role in cardiovascular control and fluid homeostasis was at first controversial. This was because a circulating kidney-derived renin angiotensin system was so similar and well established. But, the pursuit of brain RAS has proven to be correct. In the course of accepting brain RAS, high standards of proof attracted state of the art techniques in all the new developments of biolo1gy. Consequently, brain RAS is a robust concept that has enlightened neuroscience as well as cardiovascular physiology and is a model neuropeptide system. Molecular biology confirmed the components of brain RAS and their location in the brain. Transgenic mice and rats bearing renin and extra copies of angiotensinogen genes revealed the importance of brain RAS. Cre-lox delivery in vectors has enabled pinpoint gene deletion of brain RAS in discrete brain nuclei. The new concept of brain RAS includes ACE-2, Ang1–7, and prorenin and Mas receptors. Angiotensin II (ANG II) generated in the brain by brain renin has many neural effects. It activates behavioral effects by selective activation of ANG II receptor subtypes in different locations. It regulates sympathetic activity and baroreflexes and contributes to neurogenic hypertension. New findings implicate brain RAS in a much wider range of neural effects. We review brain RAS involvement in Alzheimer’s disease, stroke memory, and learning alcoholism stress depression. There is growing evidence to consider developing treatment strategies for a variety of neurological disease states based on brain RAS.
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Affiliation(s)
- M Ian Phillips
- Keck Graduate Institute, 535 Watson Drive, Claremont, CA 91711, USA.
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29
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Li Y, Lin AW, Zhang X, Wang Y, Wang X, Goodrich DW. Cancer cells and normal cells differ in their requirements for Thoc1. Cancer Res 2007; 67:6657-64. [PMID: 17638875 PMCID: PMC2804983 DOI: 10.1158/0008-5472.can-06-3234] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The evolutionarily conserved TREX (Transcription/Export) complex physically couples transcription, messenger ribonucleoprotein particle biogenesis, RNA processing, and RNA export for a subset of genes. HPR1 encodes an essential component of the S. cerevisiae TREX complex. HPR1 loss compromises transcriptional elongation, nuclear RNA export, and genome stability. Yet, HPR1 is not required for yeast viability. Thoc1 is the recently discovered human functional orthologue of HPR1. Thoc1 is expressed at higher levels in breast cancer than in normal epithelia, and expression levels correlate with tumor size and metastatic potential. Depletion of Thoc1 protein (pThoc1) in human cancer cell lines compromises cell proliferation. It is currently unclear whether Thoc1 is essential for all mammalian cells or whether cancer cells may differ from normal cells in their dependence on Thoc1. To address this issue, we have compared the requirements for Thoc1 in the proliferation and survival of isogenic normal and oncogene-transformed cells. Neoplastic cells rapidly lose viability via apoptotic cell death on depletion of pThoc1. Induction of apoptotic cell death is coincident with increased DNA damage as indicated by the appearance of phosphorylated histone H2AX. In contrast, the viability of normal cells is largely unaffected by pThoc1 loss. Normal cells lacking Thoc1 cannot be transformed by forced expression of E1A and Ha-ras, suggesting that Thoc1 may be important for neoplastic transformation. In sum, our data are consistent with the hypothesis that cancer cells require higher levels of pThoc1 for survival than normal cells. If true, pThoc1 may provide a novel molecular target for cancer therapy.
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Affiliation(s)
| | | | | | | | | | - David W. Goodrich
- Correspondence to David W. Goodrich, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, New York, 14263;
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30
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Sakai K, Agassandian K, Morimoto S, Sinnayah P, Cassell MD, Davisson RL, Sigmund CD. Local production of angiotensin II in the subfornical organ causes elevated drinking. J Clin Invest 2007; 117:1088-95. [PMID: 17404622 PMCID: PMC1838949 DOI: 10.1172/jci31242] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2006] [Accepted: 02/20/2007] [Indexed: 01/19/2023] Open
Abstract
The mechanism controlling cell-specific Ang II production in the brain remains unclear despite evidence supporting neuron-specific renin and glial- and neuronal-specific angiotensinogen (AGT) expression. We generated double-transgenic mice expressing human renin (hREN) from a neuron-specific promoter and human AGT (hAGT) from its own promoter (SRA mice) to emulate this expression. SRA mice exhibited an increase in water and salt intake and urinary volume, which were significantly reduced after chronic intracerebroventricular delivery of losartan. Ang II-like immunoreactivity was markedly increased in the subfornical organ (SFO). To further evaluate the physiological importance of de novo Ang II production specifically in the SFO, we utilized a transgenic mouse model expressing a floxed version of hAGT (hAGT(flox)), so that deletions could be induced with Cre recombinase. We targeted SFO-specific ablation of hAGT(flox) by microinjection of an adenovirus encoding Cre recombinase (AdCre). SRA(flox) mice exhibited a marked increase in drinking at baseline and a significant decrease in water intake after administration of AdCre/adenovirus encoding enhanced GFP (AdCre/AdEGFP), but not after administration of AdEGFP alone. This decrease only occurred when Cre recombinase correctly targeted the SFO and correlated with a loss of hAGT and angiotensin peptide immunostaining in the SFO. These data provide strong genetic evidence implicating de novo synthesis of Ang II in the SFO as an integral player in fluid homeostasis.
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Affiliation(s)
- Koji Sakai
- Department of Internal Medicine,
Department of Anatomy and Cell Biology, and
Center on Functional Genomics of Hypertension, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA.
Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.
Department of Cell and Developmental Biology, Weill Cornell Medical College, Cornell University, New York, New York, USA.
Department of Molecular Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Khristofor Agassandian
- Department of Internal Medicine,
Department of Anatomy and Cell Biology, and
Center on Functional Genomics of Hypertension, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA.
Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.
Department of Cell and Developmental Biology, Weill Cornell Medical College, Cornell University, New York, New York, USA.
Department of Molecular Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Satoshi Morimoto
- Department of Internal Medicine,
Department of Anatomy and Cell Biology, and
Center on Functional Genomics of Hypertension, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA.
Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.
Department of Cell and Developmental Biology, Weill Cornell Medical College, Cornell University, New York, New York, USA.
Department of Molecular Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Puspha Sinnayah
- Department of Internal Medicine,
Department of Anatomy and Cell Biology, and
Center on Functional Genomics of Hypertension, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA.
Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.
Department of Cell and Developmental Biology, Weill Cornell Medical College, Cornell University, New York, New York, USA.
Department of Molecular Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Martin D. Cassell
- Department of Internal Medicine,
Department of Anatomy and Cell Biology, and
Center on Functional Genomics of Hypertension, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA.
Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.
Department of Cell and Developmental Biology, Weill Cornell Medical College, Cornell University, New York, New York, USA.
Department of Molecular Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Robin L. Davisson
- Department of Internal Medicine,
Department of Anatomy and Cell Biology, and
Center on Functional Genomics of Hypertension, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA.
Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.
Department of Cell and Developmental Biology, Weill Cornell Medical College, Cornell University, New York, New York, USA.
Department of Molecular Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Curt D. Sigmund
- Department of Internal Medicine,
Department of Anatomy and Cell Biology, and
Center on Functional Genomics of Hypertension, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA.
Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.
Department of Cell and Developmental Biology, Weill Cornell Medical College, Cornell University, New York, New York, USA.
Department of Molecular Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
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31
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Zhu M, Weiss RS. Increased common fragile site expression, cell proliferation defects, and apoptosis following conditional inactivation of mouse Hus1 in primary cultured cells. Mol Biol Cell 2007; 18:1044-55. [PMID: 17215515 PMCID: PMC1805091 DOI: 10.1091/mbc.e06-10-0957] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Targeted disruption of the mouse Hus1 cell cycle checkpoint gene results in embryonic lethality and proliferative arrest in cultured cells. To investigate the essential functions of Hus1, we developed a system for the regulated inactivation of mouse Hus1 in primary fibroblasts. Inactivation of a loxP site-flanked conditional Hus1 allele by using a cre-expressing adenovirus resulted in reduced cell doubling, cell cycle alterations, and increased apoptosis. These phenotypes were associated with a significantly increased frequency of gross chromosomal abnormalities and an S-phase-specific accumulation of phosphorylated histone H2AX, an indicator of double-stranded DNA breaks. To determine whether these chromosomal abnormalities occurred randomly or at specific genomic regions, we assessed the stability of common fragile sites, chromosomal loci that are prone to breakage in cells undergoing replication stress. Hus1 was found to be essential for fragile site stability, because spontaneous chromosomal abnormalities occurred preferentially at common fragile sites upon conditional Hus1 inactivation. Although p53 levels increased after Hus1 loss, deletion of p53 failed to rescue the cell-doubling defect or increased apoptosis in conditional Hus1 knockout cells. In summary, we propose that Hus1 loss leads to chromosomal instability during DNA replication, triggering increased apoptosis and impaired proliferation through p53-independent mechanisms.
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Affiliation(s)
- Min Zhu
- Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853
| | - Robert S. Weiss
- Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853
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32
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Sinnayah P, Lazartigues E, Sakai K, Sharma RV, Sigmund CD, Davisson RL. Genetic ablation of angiotensinogen in the subfornical organ of the brain prevents the central angiotensinergic pressor response. Circ Res 2006; 99:1125-31. [PMID: 17053195 DOI: 10.1161/01.res.0000250259.66683.f5] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The subfornical organ (SFO) of the brain has long been considered a critical integrating center for the cardiovascular actions of the renin-angiotensin system (RAS). Early reports of angiotensin II (Ang II) immunoreactivity in the SFO and its neural projections to downstream cardiovascular nuclei raised the possibility that Ang II is produced locally and functions as a putative neurotransmitter in these circuits. However, evidence of functionally significant de novo synthesis of Ang II in the SFO has been lacking. Here, implementing spatiotemporally restricted gene ablation by way of the Cre recombinase/loxP system, we provide the first direct evidence that the local RAS in the SFO has a critical role in blood pressure regulation. Using a transgenic mouse harboring an angiotensinogen (AGT) gene modified for Cre-mediated deletion (hAGT(flox)), in combination with gene transfer of an adenovirus encoding Cre targeted to the SFO, we show that deletion of the Ang II substrate in this brain region nearly abolishes the pressor and bradycardic effects of renin infused in the CNS. Immunohistochemical analyses verified intense and restricted expression of Cre in the SFO, which paralleled the decrease in AGT expression selectively in this site. Further physiological studies confirmed the integrity of central angiotensinergic and nonangiotensinergic cardiovascular response systems in the Cre-treated mice. In addition to establishing that AGT expression in the SFO and its local conversion to Ang II has a profound effect on blood pressure, this study provides proof-of-principle of the utility of this approach for dissecting the brain RAS and other complex systems in CNS cardiovascular circuits.
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Affiliation(s)
- Puspha Sinnayah
- Department of Anatomy and Cell Biology, Roy J. and Lucille A. Carver College of Medicine, the University of Iowa, Iowa City, USA
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33
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Affiliation(s)
- Matthew E Dickson
- Medical Scientist Training Program and Genetics Program, Carver College of Medicine, University of Iowa, Iowa City, Ia 52242, USA
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34
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Tam BYY, Wei K, Rudge JS, Hoffman J, Holash J, Park SK, Yuan J, Hefner C, Chartier C, Lee JS, Jiang S, Nayak NR, Niyak NR, Kuypers FA, Ma L, Sundram U, Wu G, Garcia JA, Schrier SL, Maher JJ, Johnson RS, Yancopoulos GD, Mulligan RC, Kuo CJ. VEGF modulates erythropoiesis through regulation of adult hepatic erythropoietin synthesis. Nat Med 2006; 12:793-800. [PMID: 16799557 DOI: 10.1038/nm1428] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2006] [Accepted: 05/03/2006] [Indexed: 12/27/2022]
Abstract
Vascular endothelial growth factor (VEGF) exerts crucial functions during pathological angiogenesis and normal physiology. We observed increased hematocrit (60-75%) after high-grade inhibition of VEGF by diverse methods, including adenoviral expression of soluble VEGF receptor (VEGFR) ectodomains, recombinant VEGF Trap protein and the VEGFR2-selective antibody DC101. Increased production of red blood cells (erythrocytosis) occurred in both mouse and primate models, and was associated with near-complete neutralization of VEGF corneal micropocket angiogenesis. High-grade inhibition of VEGF induced hepatic synthesis of erythropoietin (Epo, encoded by Epo) >40-fold through a HIF-1alpha-independent mechanism, in parallel with suppression of renal Epo mRNA. Studies using hepatocyte-specific deletion of the Vegfa gene and hepatocyte-endothelial cell cocultures indicated that blockade of VEGF induced hepatic Epo by interfering with homeostatic VEGFR2-dependent paracrine signaling involving interactions between hepatocytes and endothelial cells. These data indicate that VEGF is a previously unsuspected negative regulator of hepatic Epo synthesis and erythropoiesis and suggest that levels of Epo and erythrocytosis could represent noninvasive surrogate markers for stringent blockade of VEGF in vivo.
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Affiliation(s)
- Betty Y Y Tam
- Division of Hematology, Stanford University School of Medicine, 269 Campus Drive, CCSR 1155, Stanford, California, 94305, USA
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35
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Leow CC, Wang XD, Gao WQ. Novel method of generating prostate-specific Cre-LoxP gene switching via intraductal delivery of adenovirus. Prostate 2005; 65:1-9. [PMID: 15791629 DOI: 10.1002/pros.20244] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND In order to facilitate elucidation of oncogene or tumor suppressor gene function on initiation and progression of prostate cancer, it would be advantageous to develop an effective method to generate spatially and temporally controlled gene modification in murine prostates. METHODS Adenovirus expressing Cre-recombinase (Adeno-Cre) was intraductally injected into the prostate of ROSA26 reporter mice. Immmunohistochemical and X-gal staining were performed on prostate tissue sections harvested from mice at various time points following viral injection to confirm expression and activity of Cre-recombinase, respectively. RESULTS Adenovirus was intraductally delivered to the anterior lobe of the mouse prostate. Using this method of intraductal injection, we were able to precisely obtain Adeno-Cre infection to a majority of epithelial cells but not in the stromal cells or other organs. We further demonstrated that Adeno-Cre infected epithelial cells not only expressed Cre-recombinase enzyme but more importantly, Cre-recombinase activity was revealed through positive X-gal staining in Rosa26 reporter mice, thus, confirming epithelial-specific Cre-loxP recombination in Adeno-Cre infected prostate tissue sections. CONCLUSIONS This novel method of direct genetic delivery into adult murine prostates could provide an alternative to the more expensive and time-consuming transgenic/knockout approaches. The latter also have other limitations such as the availability of cell-type specific or temporally-regulated promoters, and the complication of genetic background differences, which can potentially be complemented by the technology we describe here.
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Affiliation(s)
- Ching Ching Leow
- Department of Molecular Biology, Genentech, Inc., South San Francisco, California 94080, USA
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36
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Abstract
Hypertension remains one of the largest human health problems, because hypertensive patients carry increased risk for ischemic heart disease, stroke, atherosclerosis, and renal failure. The renin-angiotensin system (RAS) has been intensively investigated for more than 100 years because it is a powerful regulator of blood pressure, and the antihypertensive benefits of RAS inhibitors are very clear. Despite a wealth of clinical and basic studies, the precise mechanisms by which the RAS regulates blood pressure remains incomplete. In this chapter, we review data demonstrating the existence and function of intrinsic tissue RAS, with a primary focus on the brain.
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Affiliation(s)
- Koji Sakai
- Departments of Internal Medicine and Physiology & Biophysics, 3181B Medical Education and Biomedical Research Facility, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 52242 Iowa City, IA USA
| | - Curt D. Sigmund
- Departments of Internal Medicine and Physiology & Biophysics, 3181B Medical Education and Biomedical Research Facility, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 52242 Iowa City, IA USA
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37
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Sherrod M, Davis DR, Zhou X, Cassell MD, Sigmund CD. Glial-specific ablation of angiotensinogen lowers arterial pressure in renin and angiotensinogen transgenic mice. Am J Physiol Regul Integr Comp Physiol 2005; 289:R1763-9. [PMID: 16109805 DOI: 10.1152/ajpregu.00435.2005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Angiotensinogen (AGT) is mainly expressed in glial cells in close proximity to renin-expressing neurons in the brain. We previously reported that glial-specific overexpression of ANG II results in mild hypertension. Here, we tested the hypothesis that glial-derived AGT plays an important role in blood pressure regulation in hypertensive mice carrying human renin (hREN) and human AGT transgenes under the control of their own endogenous promoters. To perform a glial-specific deletion of AGT, we used an AGT transgene containing loxP sites (hAGT(flox)), so the gene can be permanently ablated in the presence of cre-recombinase expression, driven by the glial fibrillary acidic protein (GFAP) promoter. Triple transgenic mice (RAC) containing a: 1) systemically expressed hREN transgene, 2) systemically expressed hAGT(flox) transgene, and 3) GFAP-cre-recombinase were generated and compared with double transgenic mice (RA) lacking cre-recombinase. Liver and kidney hAGT mRNA levels were unaltered in RAC and RA mice, as was the level of hAGT in the systemic circulation, consistent with the absence of cre-recombinase expression in those tissues. Whereas hAGT mRNA was present in the brain of RA mice (lacking cre-recombinase), it was absent from the brain of RAC mice expressing cre-recombinase, confirming brain-specific elimination of AGT. Immunohistochemistry revealed a loss of AGT immunostaining glial cells throughout the brain in RAC mice. Arterial pressure measured by radiotelemetry was significantly lower in RAC than RA mice and unchanged from nontransgenic control mice. These data suggest that there is a major contribution of glial-AGT to the hypertensive state in mice carrying systemically expressed hREN and hAGT genes and confirm the importance of a glial source of ANG II substrate in the brain.
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Affiliation(s)
- Mikhiela Sherrod
- Genetics Graduate Program, Roy J. and Lucille A. Carver College of Medicine, Univ. of Iowa, Iowa City, Iowa 52242, USA
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38
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Guan Y, Hao C, Cha DR, Rao R, Lu W, Kohan DE, Magnuson MA, Redha R, Zhang Y, Breyer MD. Thiazolidinediones expand body fluid volume through PPARgamma stimulation of ENaC-mediated renal salt absorption. Nat Med 2005; 11:861-6. [PMID: 16007095 DOI: 10.1038/nm1278] [Citation(s) in RCA: 468] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2005] [Accepted: 06/24/2005] [Indexed: 12/13/2022]
Abstract
Thiazolidinediones (TZDs) are widely used to treat type 2 diabetes mellitus; however, their use is complicated by systemic fluid retention. Along the nephron, the pharmacological target of TZDs, peroxisome proliferator-activated receptor-gamma (PPARgamma, encoded by Pparg), is most abundant in the collecting duct. Here we show that mice treated with TZDs experience early weight gain from increased total body water. Weight gain was blocked by the collecting duct-specific diuretic amiloride and was also prevented by deletion of Pparg from the collecting duct, using Pparg (flox/flox) mice. Deletion of collecting duct Pparg decreased renal Na(+) avidity and increased plasma aldosterone. Treating cultured collecting ducts with TZDs increased amiloride-sensitive Na(+) absorption and Scnn1g mRNA (encoding the epithelial Na(+) channel ENaCgamma) expression through a PPARgamma-dependent pathway. These studies identify Scnn1g as a PPARgamma target gene in the collecting duct. Activation of this pathway mediates fluid retention associated with TZDs, and suggests amiloride might provide a specific therapy.
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Affiliation(s)
- YouFei Guan
- Division of Nephrology, Department of Medicine, Vanderbilt University School of Medicine, 21st Avenue South at Garland Avenue, Nashville, Tennessee 37232, USA
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Abstract
BACKGROUND The lack of appropriate prostate cancer models is a major problem for prostate cancer research. Progress has been made towards the development of better in vivo rodent genetic models for prostatic disease. However, an in vitro model is often preferred for the elucidation of cellular mechanisms involved in the disease. METHODS We microdissected the four prostatic lobes from young male mice, harvested the epithelial components, and grew epithelial cells from these tissues. We maintained the growth of these cells in long-term and three-dimensional culture. RESULTS We have reproducibly harvested and cultured for extended passages mouse prostatic epithelial cells (MPECs) from a variety of mouse genetic strains. These cells express luminal and basal epithelial markers as well as the androgen receptor. Additionally, MPECs form classic branching structures in a three-dimensional collagen matrix. CONCLUSIONS We have developed a novel culture system to harvest and grow MPECs in long-term culture. These cells will serve as a useful in vitro complement to studies using mouse genetic models for prostatic disease.
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Affiliation(s)
- Wendy W Barclay
- Department of Cancer Biology, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
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40
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Shui JW, Tan TH. Germline transmission and efficient DNA recombination in mouse embryonic stem cells mediated by adenoviral-Cre transduction. Genesis 2005; 39:217-23. [PMID: 15282749 DOI: 10.1002/gene.20044] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Following gene targeting, a loxP-neo-loxP cassette was introduced into ES cells. The presence of a selectable marker such as neo in the targeted allele may result in gene interference in flox mice or unexpected phenotypes due to genetic ambiguity in direct knockout mice. Typically, the neo cassette is selectively removed by transient expression of the Cre recombinase in targeted ES cell. However, this method involves a tedious process of selecting, expanding, and screening ES cell clones which may compromise germline competency. Here, we describe a novel method of combining adenovirus-Cre mediated gene recombination with ES gene targeting to facilitate efficient loxP-neo-loxP removal in ES cells. We demonstrate that adenovirus-Cre infected ES cells can retain their germline competency. The procedures described here facilitate a rapid genetic manipulation of ES cells to obtain neo-free knockout animals, multiple gene targeting, homozygous mutant ES cells ideal for in vitro characterization, or Rag-deficient blastocyst complementation.
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Affiliation(s)
- Jr-Wen Shui
- Department of Immunology, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
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41
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Phaneuf D, Moscioni AD, LeClair C, Raper SE, Wilson JM. Generation of a mouse expressing a conditional knockout of the hepatocyte growth factor gene: demonstration of impaired liver regeneration. DNA Cell Biol 2004; 23:592-603. [PMID: 15383179 DOI: 10.1089/dna.2004.23.592] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Hepatocyte growth/scatter factor (HGF/SF) is a pleiotropic cytokine originally identified as a potent mitogen for rat hepatocytes. Two HGF/SF knockout mouse models have been reported, both of which exhibit developmental abnormalities causing embryonic lethality. To circumvent this limitation, we created a mouse conditionally deficient in liver expression of HGF/SF to specifically investigate the role of this mitogen in the process of adult liver regeneration. Gene targeting technology was used to generate a mouse with loxP sites flanking exon 5 of the HGF/SF gene (ex5-flox). In the absence of cre recombinase activity, mice homozygous for ex5-flox were indistinguishable from wild-type littermates. To ablate HGF/SF gene expression in vitro, primary hepatocytes established from homozygous HGF(ex5-flox) mice were infected with a recombinant adenoviral vector coding for cre recombinase (AdCre1). PCR analyses of genomic DNA demonstrated greater than 90% ablation of the ex5-floxed gene sequence. In vivo, HGF(ex.5-flox) mice were administered AdCre1 vector and the ablation of the HGF gene confirmed by Southern blot analysis. To induce liver regeneration, mice were injected with the hepatotoxin carbon tetrachloride. The regenerative capacity of hepatocytes in mice administered cre recombinase was shown to be significantly reduced when compared with mice injected with an adenovirus expressing LacZ. A similar reduction in hepatocyte regeneration was observed in HGF(ex.5.flox) mice carrying the cre transgene under the control of the interferon-inducible (pI:pC) Mx1 promoter, as an alternative strategy to ablate the HGF/SF gene in liver. Our results confirm the mitogenic role of HGF/SF in liver regeneration.
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Affiliation(s)
- Daniel Phaneuf
- Gene Therapy Program, Division of Medical Genetics, Department of Medicine, University of Pennsylvania Medical Center, Philadelphia 19104-4268, USA
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42
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Lavoie JL, Bianco RA, Sakai K, Keen HL, Ryan MJ, Sigmund CD. Transgenic mice for studies of the renin-angiotensin system in hypertension. ACTA ACUST UNITED AC 2004; 181:571-7. [PMID: 15283772 DOI: 10.1111/j.1365-201x.2004.01332.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Hypertension is a polygenic and multi-factorial disorder that is extremely prevalent in western societies, and thus has received a great deal of attention by the research community. The renin-angiotensin system has a strong impact on the control of blood pressure both in the short- and long-term, making it one of the most extensively studied physiological systems. Nevertheless, despite decades of research, the specific mechanisms implicated in its action on blood pressure and electrolyte balance, as well as its integration with other cardiovascular pathways remains incomplete. The production of transgenic models either over-expressing or knocking-out specific components of the renin-angiotensin system has given us a better understanding of its role in the pathogenesis of hypertension. Moreover, our attention has recently been refocused on local tissue renin-angiotensin systems and their physiological effect on blood pressure and end-organ damage. Herein, we will review studies using genetic manipulation of animals to determine the role of the endocrine and tissue renin-angiotensin system in hypertension. We will also discuss some untraditional approaches to target the renin-angiotensin system in the kidney.
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Affiliation(s)
- J L Lavoie
- Department of Internal Medicine and Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, USA
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43
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Sundaresan G, Paulmurugan R, Berger F, Stiles B, Nagayama Y, Wu H, Gambhir SS. MicroPET imaging of Cre-loxP-mediated conditional activation of a herpes simplex virus type 1 thymidine kinase reporter gene. Gene Ther 2004; 11:609-18. [PMID: 14724687 PMCID: PMC4141556 DOI: 10.1038/sj.gt.3302194] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Site-specific recombination tools such as the Cre-loxP system are used to create animal models where conditional gene deletion/activation studies are required. In the current proof of principle study, we have demonstrated that a PET reporter gene (PRG), the herpes simplex virus type 1 thymidine kinase (HSV1-tk), can be made to remain silent and can be activated by Cre-loxP-mediated recombination in cell culture and in living mice. An adenovirus carrying a silent HSV1-tk was tail-vein injected (1 x 10(9) PFU) in six transgenic mice that express Cre recombinase in their liver (Cre+) and in four control mice (Cre-). The liver-specific expression of the PRG in Cre+ mice was detected in the microPET following injection of the reporter probe, 9-[4-fluoro-3-(hydroxymethyl)butyl]guanine ([(18)F]-FHBG). The [(18)F]-FHBG accumulation in the liver in terms of percent-injected dose per gram of tissue was 7.72+/-1.13 for the Cre+ mice and 0.10+/-0.02 for the Cre- mice (P<0.05) 48 h after adenoviral injection. These results were further validated by quantitative RT-PCR, western blotting and by in vitro assays for herpes simplex virus type 1 thymidine kinase enzyme activity. Thus by using the Cre-loxP system it is possible to modulate a PRG and noninvasively monitor the extent of Cre-loxP-mediated gene activation by imaging in a microPET scanner.
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Affiliation(s)
- G Sundaresan
- Crump Institute for Molecular Imaging, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - R Paulmurugan
- Crump Institute for Molecular Imaging, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - F Berger
- Crump Institute for Molecular Imaging, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - B Stiles
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Y Nagayama
- Department of Pharmacology, Nagasaki University School of Medicine, Nagasaki, Japan
| | - H Wu
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - SS Gambhir
- Crump Institute for Molecular Imaging, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Jonsson Comprehensive Cancer Center, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Molecular Imaging Program at Stanford, Department of Radiology and Bio-X Program, Stanford, CA, USA
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44
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Phillips MI. A Cre-loxP solution for defining the brain renin-angiotensin system. Focus on "Targeted viral delivery of Cre recombinase induces conditional gene deletion in cardiovascular circuits of the mouse brain". Physiol Genomics 2004; 18:1-3. [PMID: 15205485 DOI: 10.1152/physiolgenomics.00115.2004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
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Sinnayah P, Lindley TE, Staber PD, Davidson BL, Cassell MD, Davisson RL. Targeted viral delivery of Cre recombinase induces conditional gene deletion in cardiovascular circuits of the mouse brain. Physiol Genomics 2004; 18:25-32. [PMID: 15069166 DOI: 10.1152/physiolgenomics.00048.2004] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The Cre/loxP system has shown promise for investigating genes involved in nervous system function and pathology, although its application for studying central neural regulation of cardiovascular function and disease has not been explored. Here, we report for the first time that recombination of loxP-flanked genes can be achieved in discrete cardiovascular regulatory nuclei of adult mouse brain using targeted delivery of adenovirus (Ad) or feline immunodeficiency virus (FIV) bearing Cre recombinase (Ad-Cre, FIV-Cre). Single stereotaxic microinjections of Ad-Cre or FIV-Cre into specific nuclei along the subfornical organ-hypothalamic-hypophysial and brain stem-parabrachial axes resulted in robust and highly localized gene deletion as early as 7 days and for as long as 3 wk in a reporter mouse model in which Cre recombinase activates beta-galactosidase expression. An even greater selectivity in Cre-mediated gene deletion could be achieved in unique subpopulations of cells, such as vasopressin-synthesizing magnocellular neurons, by delivering Ad-Cre via retrograde transport. Moreover, Ad-Cre and FIV-Cre induced gene recombination in differential cell populations within these cardiovascular nuclei. FIV-Cre infection resulted in LacZ activation selectively in neurons, whereas both neuronal and glial cell types underwent gene recombination upon infection with Ad-Cre. These results establish the feasibility of using a combination of viral and Cre/loxP technologies to target specific cardiovascular nuclei in the brain for conditional gene modification and suggest the potential of this approach for determining the functional role of genes within these sites.
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Affiliation(s)
- Puspha Sinnayah
- Department of Anatomy and Cell Biology, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa 52242, USA
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Abstract
The lung is a complex organ consisting of numerous cell types that function to ensure sufficient gas exchange to oxygenate the blood. In order to accomplish this function, the lung must be exposed to the external environment and at the same time maintain a homeostatic balance between its function in gas exchange and the maintenance of inflammatory balance. During the past two decades, as molecular methodologies have evolved with the sequencing of entire genomes, the use of in vivo models to elucidate the molecular mechanisms involved in pulmonary physiology and disease have increased. The mouse has emerged as a potent model to investigate pulmonary physiology due to the explosion in molecular methods that now allow for the developmental and tissue-specific regulation of gene transcription. Initial efforts to manipulate gene expression in the mouse genome resulted in the generation of transgenic mice characterized by the constitutive expression of a specific gene and knockout mice characterized by the ablation of a specific gene. The utility of these original mouse models was limited, in many cases, by phenotypes resulting in embryonic or neonatal lethality that prevented analysis of the impact of the genetic manipulation on pulmonary biology. Second-generation transgenic mouse models employ multiple strategies that can either activate or silence gene expression thereby providing extensive temporal and spatial control of the experimental parameters of gene expression. These highly regulated mouse models are intended to serve as a foundation for further investigation of the molecular basis of human disease such as tumorigenesis. This review describes the principles, progress, and application of systems that are currently employed in the conditional regulation of gene expression in the investigation of lung cancer.
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Affiliation(s)
- I Kwak
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
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Lee JH, Yi SMP, Anderson ME, Berger KL, Welsh MJ, Klingelhutz AJ, Ozbun MA. Propagation of infectious human papillomavirus type 16 by using an adenovirus and Cre/LoxP mechanism. Proc Natl Acad Sci U S A 2004; 101:2094-9. [PMID: 14769917 PMCID: PMC357057 DOI: 10.1073/pnas.0308615100] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Human papillomavirus type 16 (HPV16) infection is a major risk factor for the development of squamous cell cancers of the cervix and of the head and neck. A major barrier to understanding the progression from initial infection to cancer has been the lack of in vitro models that allow infection, replication, and persistence of the viral genome as an episome in differentiated epithelial cells. To overcome this barrier, we designed an adenoviral delivery vector that contained a full HPV16 genome flanked by LoxP homologous recombination sites and a fluorescent reporter that was expressed only after the HPV genome was excised by Cre recombinase. This system delivered circular HPV16 genomes to cervical epithelial cells and well differentiated human airway epithelia. After delivery, the HPV16 genome replicated and persisted as an episome in cervical keratinocytes. These cells developed an immortalized phenotype and a dysplastic epithelial appearance. Moreover, induction of differentiation led to the expression of late genes and production of infectious HPV16 virions. This work provides a means of introducing biologically active HPV genomes into epithelial cells, which are normally difficult to transfect. These methods allow the study of HPV genome replication and gene expression in the earliest stages of HPV genome establishment, and they may provide a means to study nononcogenic HPV viral types.
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Affiliation(s)
- John H Lee
- Department of Otolaryngology, Head and Neck Surgery, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA.
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Kasparov S, Teschemacher AG, Hwang DY, Kim KS, Lonergan T, Paton JFR. Viral vectors as tools for studies of central cardiovascular control. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2004; 84:251-77. [PMID: 14769439 DOI: 10.1016/j.pbiomolbio.2003.11.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
During the last few years physiological genomics has been the most rapidly developing area of physiology. Given the current ease of obtaining information about nucleotide sequences found in genomes and the vast amount of readily available clones, one of the most pertinent tasks is to find out about the roles of the individual genes and their families under normal and pathological conditions. Viral gene delivery into the brain is a powerful tool, which can be used to address a wide range of questions posed by physiological genomics including central nervous mechanisms regulating the cardio-vascular system. In this paper, we will give a short overview of current data obtained in this field using viral vectors and then look critically at the technology of viral gene transfer.
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Affiliation(s)
- S Kasparov
- Department of Physiology, University of Bristol, Bristol, UK.
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Bianco RA, Keen HL, Lavoie JL, Sigmund CD. Untraditional methods for targeting the kidney in transgenic mice. Am J Physiol Renal Physiol 2003; 285:F1027-33. [PMID: 14600026 DOI: 10.1152/ajprenal.00207.2003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
With the completion of the human genome project and the sequencing of many genomes of experimental models, there is a pressing need to determine the physiological relevance of newly identified genes. Gene-targeting approaches have become an important tool in our arsenal to dissect the significance of genes expressed in many tissues. A wealth of experimental models has been made to assess the role of gene expression in renal function and development. The development of new and informative models is presently limited by the anatomic complexity of the kidney and the lack of cell-specific promoters to target the numerous diverse cell types in that organ. Because of this, new approaches may have to be developed. In this review, we will discuss several untraditional methods to target gene expression to the kidney. These approaches should provide some additional tricks and tools to help in developing additional informative models for studying renal physiology.
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Affiliation(s)
- Robert A Bianco
- Dept. of Internal Medicine, 3181B Medical Education and Biomedical Research Facility, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
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Lavoie JL, Sigmund CD. Minireview: overview of the renin-angiotensin system--an endocrine and paracrine system. Endocrinology 2003; 144:2179-83. [PMID: 12746271 DOI: 10.1210/en.2003-0150] [Citation(s) in RCA: 382] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Since the discovery of renin as a pressor substance in 1898, the renin-angiotensin (RAS) system has been extensively studied because it remains a prime candidate as a causative factor in the development and maintenance of hypertension. Indeed, some of the properties of the physiologically active component of the RAS, angiotensin II, include vasoconstriction, regulation of renal sodium and water absorption, and increasing thirst. Initially, its affect on blood pressure was thought to be mediated primarily through the classical endocrine pathway; that is, the generation of blood-borne angiotensin with actions in target tissues. More recently, however, it has become appreciated that a local autocrine or paracrine RAS may exist in a number of tissues, and that these may also play a significant role in regulating blood pressure. Some of the difficulties in studying tissue RAS stem from the limitations of pharmacology in not differentiating between RAS products made systemically from those synthesized locally. However, the development of transgenic animals with highly specific promoters to target the RAS to specific tissues provided important tools to dissect these systems. Thus, this minireview will discuss recent advances in understanding the relationship between endocrine and paracrine (tissue) RAS using transgenic models.
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Affiliation(s)
- Julie L Lavoie
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA
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