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Seeman T, Hamdani G, Mitsnefes M. Hypertensive crisis in children and adolescents. Pediatr Nephrol 2019; 34:2523-2537. [PMID: 30276533 DOI: 10.1007/s00467-018-4092-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 09/17/2018] [Accepted: 09/18/2018] [Indexed: 12/28/2022]
Abstract
Hypertensive crisis is a relatively rare condition in children. However, if not treated, it might be life-threatening and lead to irreversible damage of vital organs. Clinical presentation of patients with hypertensive crisis can vary from very mild (hypertensive urgency) to severe symptoms (hypertensive emergency) despite similarly high blood pressure (BP). Individualized assessment of patients presenting with high BP with emphasis on the evaluation of end-organ damage rather than on the specific BP number is a key in guiding physician's initial management of a hypertensive crisis. The main aim of the treatment of hypertensive crisis is the prevention or treatment of life-threatening complications of hypertension-induced organ dysfunction, including neurologic, ophthalmologic, renal, and cardiac complications. While the treatment strategy must be directed toward the immediate reduction of BP to reduce the hypertensive damage to these organs, it should not be at a too fast rate to cause hypoperfusion of vital organs by an excessively rapid reduction of BP. Thus, intravenous continuous infusions rather than intravenous boluses of antihypertensive medications should be the preferable mode of initial treatment of children with hypertensive emergency.
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Affiliation(s)
- Tomáš Seeman
- Department of Pediatrics and Biomedical Center, 2nd Faculty of Medicine and Faculty of Medicine in Pilsen, Charles University in Prague, V Uvalu 84, 15006, Prague 5, Czech Republic. .,Motol University Hospital, V Uvalu 84, 15006, Prague 5, Czech Republic.
| | - Gilad Hamdani
- Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Mark Mitsnefes
- Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
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20-Hydroxyeicosatetraenoic acid antagonist attenuates the development of malignant hypertension and reverses it once established: a study in Cyp1a1-Ren-2 transgenic rats. Biosci Rep 2018; 38:BSR20171496. [PMID: 30054426 PMCID: PMC6131326 DOI: 10.1042/bsr20171496] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 07/09/2018] [Accepted: 07/19/2018] [Indexed: 01/13/2023] Open
Abstract
We hypothesized that vascular actions of 20-hydroxyeicosatetraenoic acid (20-HETE), the product of cytochrome P450 (CYP450)-dependent ω-hydroxylase, potentiate prohypertensive actions of angiotensin II (ANG II) in Cyp1a1-Ren-2 transgenic rats, a model of ANG II-dependent malignant hypertension. Therefore, we evaluated the antihypertensive effectiveness of 20-HETE receptor antagonist (AAA) in this model. Malignant hypertension was induced in Cyp1a1-Ren-2 transgenic rats by activation of the renin gene using indole-3-carbinol (I3C), a natural xenobiotic. Treatment with AAA was started either simultaneously with induction of hypertension or 10 days later, during established hypertension. Systolic blood pressure (SBP) was monitored by radiotelemetry, indices of renal and cardiac injury, and kidney ANG II levels were determined. In I3C-induced hypertensive rats, early AAA treatment reduced SBP elevation (to 161 ± 3 compared with 199 ± 3 mmHg in untreated I3C-induced rats), reduced albuminuria, glomerulosclerosis index, and cardiac hypertrophy (P<0.05 in all cases). Untreated I3C-induced rats showed augmented kidney ANG II (405 ± 14 compared with 52 ± 3 fmol/g in non-induced rats, P<0.05) which was markedly lowered by AAA treatment (72 ± 6 fmol/g). Remarkably, in TGR with established hypertension, AAA also decreased SBP (from 187 ± 4 to 158 ± 4 mmHg, P<0.05) and exhibited organoprotective effects in addition to marked suppression of kidney ANG II levels. In conclusion, 20-HETE antagonist attenuated the development and largely reversed the established ANG II-dependent malignant hypertension, likely via suppression of intrarenal ANG II levels. This suggests that intrarenal ANG II activation by 20-HETE is important in the pathophysiology of this hypertension form.
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Jíchová Š, Doleželová Š, Kopkan L, Kompanowska-Jezierska E, Sadowski J, Červenka L. Fenofibrate Attenuates Malignant Hypertension by Suppression of the Renin-angiotensin System: A Study in Cyp1a1-Ren-2 Transgenic Rats. Am J Med Sci 2016; 352:618-630. [DOI: 10.1016/j.amjms.2016.09.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 08/17/2016] [Accepted: 09/21/2016] [Indexed: 11/29/2022]
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4
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Huang H, Luo Y, Liang Y, Long X, Peng Y, Liu Z, Wen X, Jia M, Tian R, Bai C, Li C, He F, Lin Q, Wang X, Dong X. CD4(+)CD25(+) T Cells in primary malignant hypertension related kidney injury. Sci Rep 2016; 6:27659. [PMID: 27278520 PMCID: PMC4899787 DOI: 10.1038/srep27659] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 05/18/2016] [Indexed: 01/10/2023] Open
Abstract
CD4+CD25+ T cells are critical for maintenance of immunologic self-tolerance. We measured the number of CD4+CD25+ cells in the patients with primary malignant hypertension related kidney injury, to explore the molecular pathogenesis of this disease. We selected 30 patients with primary malignant hypertension related kidney injury and 30 healthy volunteers. Information on clinical characteristics and laboratory tests was obtained from each subject. The number of CD4+CD25+ cells and glomerular injury were assessed by flow cytometry and histopathology, respectively. Both serum IL-2, IL-4, and IL-6 and endothelial cell markers were analyzed by ELISA. ADAMTS13 antibody was detected by Western blotting. CD4+CD25+ cells were significantly reduced in patients with primary malignant hypertension related kidney injury compared to controls (P < 0.05). The number of CD4+CD25+ cells was negatively related to blood urea nitrogen, serum uric acid, proteinuria, and supernatant IL-4; whereas positively associated with estimated glomerular filtration rate in patients. Gradually decreasing CD4+CD25+ cells were also found as increasing renal injury. Additionally, patients exhibited increasing supernatant IL-4, serum IL-2 and IL-6, endothelial cell markers, and anti-ADAMTS13 antibody compared with controls (all P < 0.05). CD4+CD25+ cells may play a key role in the pathogenesis of primary malignant hypertension related kidney injury.
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Affiliation(s)
- Hongdong Huang
- Division of Nephrology, Beijing Shijitan Hospital, Capital Medical University, The 9th Affiliated Hospital of Peking University, Beijing, P.R. China.,Division of Nephrology, Hunan Normal University, Hunan Provincial People's Hospital of China, Changsha, Hunan Province, P.R. China
| | - Yang Luo
- Division of Nephrology, Beijing Shijitan Hospital, Capital Medical University, The 9th Affiliated Hospital of Peking University, Beijing, P.R. China
| | - Yumei Liang
- Division of Nephrology, Hunan Normal University, Hunan Provincial People's Hospital of China, Changsha, Hunan Province, P.R. China
| | - Xidai Long
- Department of Liver Surgery, the Affiliated Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, P.R. China
| | - Youming Peng
- Hunan Key Laboratory of Nephrology and Hemoperfusion, Division of Nephrology, Second Xiangya Hospital of Central South University, Changsha, Hunan Province, P.R. China
| | - Zhihua Liu
- Division of Nephrology, Beijing Shijitan Hospital, Capital Medical University, The 9th Affiliated Hospital of Peking University, Beijing, P.R. China
| | - Xiaojun Wen
- Division of Nephrology, Beijing Shijitan Hospital, Capital Medical University, The 9th Affiliated Hospital of Peking University, Beijing, P.R. China
| | - Meng Jia
- Division of Nephrology, Beijing Shijitan Hospital, Capital Medical University, The 9th Affiliated Hospital of Peking University, Beijing, P.R. China
| | - Ru Tian
- Division of Nephrology, Beijing Shijitan Hospital, Capital Medical University, The 9th Affiliated Hospital of Peking University, Beijing, P.R. China
| | - Chengli Bai
- Division of Nephrology, Beijing Shijitan Hospital, Capital Medical University, The 9th Affiliated Hospital of Peking University, Beijing, P.R. China
| | - Cui Li
- Division of Nephrology, Beijing Shijitan Hospital, Capital Medical University, The 9th Affiliated Hospital of Peking University, Beijing, P.R. China
| | - Fuliang He
- Department of Interventional Therapy, Beijing Shijitan Hospital, Capital Medical University, The 9th Affiliated Hospital of Peking University, Beijing, P.R. China.,Section of Hematology/Oncology, Section of Gastroenterology, Stephenson Cancer Center, Department of Internal Medicine, College of Medicine, The University of Oklahoma Health Sciences Center, USA
| | - Qiushi Lin
- Section of Hematology/Oncology, Section of Gastroenterology, Stephenson Cancer Center, Department of Internal Medicine, College of Medicine, The University of Oklahoma Health Sciences Center, USA
| | - Xueyan Wang
- Center of Allergy, Beijing Shijitan Hospital, Capital Medical University, Beijing, P.R. China
| | - Xiaoqun Dong
- Department of Interventional Therapy, Beijing Shijitan Hospital, Capital Medical University, The 9th Affiliated Hospital of Peking University, Beijing, P.R. China.,Section of Hematology/Oncology, Section of Gastroenterology, Stephenson Cancer Center, Department of Internal Medicine, College of Medicine, The University of Oklahoma Health Sciences Center, USA
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5
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Husková Z, Kopkan L, Červenková L, Doleželová Š, Vaňourková Z, Škaroupková P, Nishiyama A, Kompanowska-Jezierska E, Sadowski J, Kramer HJ, Červenka L. Intrarenal alterations of the angiotensin-converting enzyme type 2/angiotensin 1-7 complex of the renin-angiotensin system do not alter the course of malignant hypertension in Cyp1a1-Ren-2 transgenic rats. Clin Exp Pharmacol Physiol 2016; 43:438-49. [DOI: 10.1111/1440-1681.12553] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 01/15/2016] [Accepted: 01/26/2016] [Indexed: 01/13/2023]
Affiliation(s)
- Zuzana Husková
- Centre for Experimental Medicine; Institute for Clinical and Experimental Medicine; Prague Czech Republic
| | - Libor Kopkan
- Centre for Experimental Medicine; Institute for Clinical and Experimental Medicine; Prague Czech Republic
| | - Lenka Červenková
- Centre for Experimental Medicine; Institute for Clinical and Experimental Medicine; Prague Czech Republic
| | - Šárka Doleželová
- Centre for Experimental Medicine; Institute for Clinical and Experimental Medicine; Prague Czech Republic
| | - Zdeňka Vaňourková
- Centre for Experimental Medicine; Institute for Clinical and Experimental Medicine; Prague Czech Republic
| | - Petra Škaroupková
- Centre for Experimental Medicine; Institute for Clinical and Experimental Medicine; Prague Czech Republic
| | | | - Elzbieta Kompanowska-Jezierska
- Department of Renal and Body Fluid Physiology; Mossakowski Medical Research Centre; Polish Academy of Science; Warsaw Poland
| | - Janusz Sadowski
- Department of Renal and Body Fluid Physiology; Mossakowski Medical Research Centre; Polish Academy of Science; Warsaw Poland
| | - Herbert J. Kramer
- Section of Nephrology; Department of Medicine; University of Bonn; Bonn Germany
| | - Luděk Červenka
- Centre for Experimental Medicine; Institute for Clinical and Experimental Medicine; Prague Czech Republic
- Department of Pathophysiology; 2nd Faculty of Medicine; Charles University; Prague Czech Republic
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Krafft PR, Bailey EL, Lekic T, Rolland WB, Altay O, Tang J, Wardlaw JM, Zhang JH, Sudlow CLM. Etiology of stroke and choice of models. Int J Stroke 2012; 7:398-406. [PMID: 22712741 DOI: 10.1111/j.1747-4949.2012.00838.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Animal models of stroke contribute to the development of better stroke prevention and treatment through studies investigating the pathophysiology of different stroke subtypes and by testing promising treatments before trials in humans. There are two broad types of animal models: those in which stroke is induced through artificial means, modeling the consequences of a vascular insult but not the vascular pathology itself; and those in which strokes occur spontaneously. Most animal models of stroke are in rodents due to cost, ethical considerations, availability of standardized neurobehavioral assessments, and ease of physiological monitoring. While there are similarities in cerebrovascular anatomy and pathophysiology between rodents and humans, there are also important differences, including brain size, length and structure of perforating arteries, and gray to white matter ratio, which is substantially lower in humans. The wide range of rodent models of stroke includes models of global and focal ischemia, and of intracerebral and sub-arachnoid hemorrhage. The most widely studied model of spontaneous stroke is the spontaneously hypertensive stroke-prone rat, in which the predominant lesions are small subcortical infarcts resulting from a vascular pathology similar to human cerebral small vessel disease. Important limitations of animal models of stroke - they generally model only certain aspects of the disease and do not reflect the heterogeneity in severity, pathology and comorbidities of human stroke - and key methodological issues (especially the need for adequate sample size, randomization, and blinding in treatment trials) must be carefully considered for the successful translation of pathophysiological concepts and therapeutics from bench to bedside.
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Affiliation(s)
- Paul R Krafft
- Department of Physiology, School of Medicine, Loma Linda University, Loma Linda, CA, USA
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7
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Abstract
Stroke is a devastating neurological disease with limited functional recovery. Stroke affects all cellular elements of the brain and impacts areas traditionally classified as both gray matter and white matter. In fact, stroke in subcortical white matter regions of the brain accounts for approximately 30% of all stroke subtypes, and white matter injury is a component of most classes of stroke damage. However, most basic scientific information in stroke cell death and neural repair relates principally to neuronal cell death and repair. Despite an emerging biological understanding of white matter development, adult function, and reorganization in inflammatory diseases, such as multiple sclerosis, little is known of the specific molecular and cellular events in white matter ischemia. This limitation stems in part from the difficulty in generating animal models of white matter stroke. This review will discuss recent progress in studies of animal models of white matter stroke, and the emerging principles of cell death and repair in oligodendrocytes, axons, and astrocytes in white matter ischemic injury.
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Affiliation(s)
- Elif G. Sozmen
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095 USA
| | - Jason D. Hinman
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095 USA
| | - S. Thomas Carmichael
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095 USA
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Liu X, Bellamy COC, Bailey MA, Mullins LJ, Dunbar DR, Kenyon CJ, Brooker G, Kantachuvesiri S, Maratou K, Ashek A, Clark AF, Fleming S, Mullins JJ. Angiotensin-converting enzyme is a modifier of hypertensive end organ damage. J Biol Chem 2009; 284:15564-72. [PMID: 19307186 PMCID: PMC2708853 DOI: 10.1074/jbc.m806584200] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2008] [Revised: 03/06/2009] [Indexed: 11/06/2022] Open
Abstract
Severe forms of hypertension are characterized by high blood pressure combined with end organ damage. Through the development and refinement of a transgenic rat model of malignant hypertension incorporating the mouse renin gene, we previously identified a quantitative trait locus on chromosome 10, which affects malignant hypertension severity and morbidity. We next generated an inducible malignant hypertensive model where the timing, severity, and duration of hypertension was placed under the control of the researcher, allowing development of and recovery from end organ damage to be investigated. We have now generated novel consomic Lewis and Fischer rat strains with inducible hypertension and additional strains that are reciprocally congenic for the refined chromosome 10 quantitative trait locus. We have captured a modifier of end organ damage within the congenic region and, using a range of bioinformatic, biochemical and molecular biological techniques, have identified angiotensin-converting enzyme as the modifier of hypertension-induced tissue microvascular injury. Reciprocal differences between angiotensin-converting enzyme and the anti-inflammatory tetrapeptide, N-acetyl-Ser-Asp-Lys-Pro in the kidney, a tissue susceptible to end organ damage, suggest a mechanism for the amelioration of hypertension-dependent damage.
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Affiliation(s)
- Xiaojun Liu
- From the Molecular Physiology Laboratory, Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | | | - Matthew A. Bailey
- From the Molecular Physiology Laboratory, Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Linda J. Mullins
- From the Molecular Physiology Laboratory, Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Donald R. Dunbar
- From the Molecular Physiology Laboratory, Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Christopher J. Kenyon
- From the Molecular Physiology Laboratory, Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Gillian Brooker
- From the Molecular Physiology Laboratory, Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | | | - Klio Maratou
- the Medical Research Council Clinical Sciences Centre, Hammersmith Hospital, London W12 ONN, United Kingdom, and
| | - Ali Ashek
- From the Molecular Physiology Laboratory, Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Allan F. Clark
- From the Molecular Physiology Laboratory, Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | | | - John J. Mullins
- From the Molecular Physiology Laboratory, Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
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9
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Endothelin receptor blockade does not affect blood pressure or angiotensin II levels in CYP1A1-Ren-2 transgenic rats with acutely induced hypertension. Vascul Pharmacol 2009; 50:194-9. [DOI: 10.1016/j.vph.2009.01.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2008] [Revised: 12/08/2008] [Accepted: 01/21/2009] [Indexed: 11/22/2022]
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10
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Do in vivo experimental models reflect human cerebral small vessel disease? A systematic review. J Cereb Blood Flow Metab 2008; 28:1877-91. [PMID: 18698331 DOI: 10.1038/jcbfm.2008.91] [Citation(s) in RCA: 185] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cerebral small vessel disease (SVD) is a major cause of stroke and dementia. Pathologically, three lesions are seen: small vessel arteriopathy, lacunar infarction, and diffuse white matter injury (leukoaraiosis). Appropriate experimental models would aid in understanding these pathologic states and also in preclinical testing of therapies. The objective was to perform a systematic review of animal models of SVD and determine whether these resemble four key clinicopathologic features: (1) small, discrete infarcts; (2) small vessel arteriopathy; (3) diffuse white matter damage; (4) cognitive impairment. Fifteen different models were included, under four categories: (1) embolic injuries (injected blood clot, photochemical, detergent-evoked); (2) hypoperfusion/ischaemic injury (bilateral common carotid occlusion/stenosis, striatal endothelin-1 injection, striatal mitotoxin 3-NPA); (3) hypertension-based injuries (surgical narrowing of the aorta, or genetic mutations, usually in the renin-angiotensin system); (4) blood vessel damage (injected proteases, endothelium-targeting viral infection, or genetic mutations affecting vessel walls). Chronic hypertensive models resembled most key features of SVD, and shared the major risk factors of hypertension and age with human SVD. The most-used model was the stroke-prone spontaneously hypertensive rat (SHR-SP). No model described all features of the human disease. The optimal choice of model depends on the aspect of pathophysiology being studied.
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Dann CT. New technology for an old favorite: lentiviral transgenesis and RNAi in rats. Transgenic Res 2007; 16:571-80. [PMID: 17682833 DOI: 10.1007/s11248-007-9121-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2007] [Accepted: 06/29/2007] [Indexed: 01/15/2023]
Abstract
The ability to produce targeted deletions in the mouse genome via homologous recombination has been a hallmark of mouse genetics, and has lead to the production of thousands of gene knockouts. New technologies are making it possible to disrupt gene function in many other species. This article reviews some of these methods, highlighting the powerful combination of lentiviral vectors with RNA interference (RNAi), which allows one to produce transgenic animals expressing short hairpin RNA (shRNA) to "knock down" specific gene expression. Lentiviral transduction of embryos has been shown to be a highly efficient means of transgenesis, and is particularly promising for animals that are considered difficult to genetically modify by DNA pronuclear injection. This technique has been popular for introducing transgenes for shRNA expression into rodents and its utility for creating new genetic models has already been demonstrated. One of the purported advantages of in vivo RNAi is that shRNA expressing transgenes would be expected to act in a dominant nature, resulting in a phenotype in founder animals. However, one possible concern with lentiviral-mediated transgenesis is the potential for mosaicism in founders, and the data for this phenomenon and the potential causes and solutions are discussed. Emphasis is placed on the application of in vivo RNAi, and other reverse genetic methods, for creating new genetic models in the rat.
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Affiliation(s)
- Christina Tenenhaus Dann
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9051, USA.
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12
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Efrati S, Berman S, Goldfinger N, Erez N, Averbukh Z, Golik A, Rotter V, Weissgarten J. Enhanced angiotensin II production by renal mesangium is responsible for apoptosis/proliferation of endothelial and epithelial cells in a model of malignant hypertension. J Hypertens 2007; 25:1041-52. [PMID: 17414669 DOI: 10.1097/hjh.0b013e32807fb09c] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The systemic renin-angiotensin system (RAS) plays a crucial role in the pathogenesis of malignant hypertension. However, the intrarenal RAS might be at least equally important. We investigated the relationship between intrarenal RAS and mesangial, epithelial and endothelial cell proliferation/apoptosis in a model of malignant hypertension. METHODS Cultured murine mesangial cells were subjected to 160 mmHg hydrostatic pressure for 1 h. Angiotensin II was assessed by radio-immunoassay (RIA); pro-metalloproteinase-1 (pro-MMP-1) by enzyme-linked immunosorbent assay (ELISA); hydrogen peroxide (H2O2) by photocolorimetric assay, apoptosis by terminal dUTP (2-deoxyuridine 5'-triphosphate) nick-end labelling (TUNEL), p53 by western blot and proliferation by [H]thymidine incorporation, with or without angiotensin II and/or angiotensin II type 1/angiotensin II type 2 (AT-1/AT-2) receptor blockers. Endothelial and epithelial cells were similarly treated, and the same parameters evaluated. Further, untreated cells of both lines were cultured in conditioned medium of mesangial cells exposed to pressure. Their proliferation, apoptosis and angiotensin II production were also assessed. RESULTS High hydrostatic pressure increased angiotensin II production by mesangial cells, coinciding with augmented apoptosis and proliferation. Co-stimulation with exogenous angiotensin II amplified both effects. Pressure per se evoked no response in endothelial/epithelial cells, while exogenous angiotensin II stimulated proliferation and apoptosis. No augmentation of p53 expression was evident. These effects were abolished by anti-angiotensin-II peptide, saralasine and losartan, but not by PD123319. Incubation of untreated cells in medium of mesangium subjected to pressure, augmented proliferation and apoptosis. No significant changes were noticed in pro-MMP or H2O2. CONCLUSIONS Mesangium plays a deleterious role in the pathogenesis of malignant hypertension. High hydrostatic pressure stimulates angiotensin II synthesis by mesangial cells. The latter is responsible for hypercellularity and apoptotic death of mesangial, endothelial and epithelial cells. In this model, exaggerated apoptosis and proliferation are mediated via the angiotensin II pathway independently of p53 gene activation.
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Affiliation(s)
- Shai Efrati
- Division of Nephrology, Assaf Harofeh Medical Center, Zerifin, Israel.
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13
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Filipiak WE, Saunders TL. Advances in transgenic rat production. Transgenic Res 2006; 15:673-86. [PMID: 17009096 DOI: 10.1007/s11248-006-9002-x] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2005] [Accepted: 04/11/2006] [Indexed: 11/29/2022]
Abstract
Predictable and reproducible production of transgenic rats from a standardized input of egg donors and egg recipients is essential for routine rat model production. In the course of establishing a transgenic rat service, transgenic founders were produced from three transgenes in outbred Sprague-Dawley (SD) rats and four transgenes in inbred Fischer 344 (F344) rats. Key parameters that affect transgenesis efficiency were assessed, including superovulation treatments, methods to prepare pseudopregnant recipients, and microinjection technique. Five superovulation regimens were compared and treatment with 20 IU PMSG and 30 IU HCG was selected for routine use. Four methods to prepare pseudopregnant egg recipients were compared and estrus synchronization with LHRHa and mating to vasectomized males was selected as most effective. More than 80% of eggs survived microinjection when modified pronuclear microinjection needles and DNA buffers were used. The efficiencies of transgenic production in rats and C57BL/6J (B6J) mice were compared to provide a context for assessing the difficulty of transgenic rat production. Compared to B6J mice, SD rat transgenesis required fewer egg donors per founder, fewer pseudopregnant egg recipients per founder, and produced more founders per eggs microinjected. Similar numbers of injection days were required to produce founders. These results suggest that SD rat transgenesis can be more efficient than B6J mouse transgenesis with the appropriate technical refinements. Advances in transgenic rat production have the potential to increase access to rat models.
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Affiliation(s)
- Wanda E Filipiak
- Transgenic Animal Model Core, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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14
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Abstract
PURPOSE OF REVIEW This review summarizes recent insights into to the pathophysiology of hypertensive crisis with the emphasis on newly discovered molecular mechanisms underlying hypertension and also updates current therapeutic options for treating hypertensive crisis in children. RECENT FINDINGS There is growing evidence that the renin-angiotensin system plays a key role in the pathogenesis of hypertensive crises. Recent studies have shown that oxidative stress and factors affecting endothelial function are also important. Treatment of hypertensive crisis still focuses on lowering of blood pressure in an expeditious but safe manner. There is growing experience with IV nicardipine, which is becoming a viable alternative to sodium nitroprusside in children. SUMMARY Current knowledge of hypertensive crisis emphasizes the need for additional animal and translational studies with the goal of identifying the underlying molecular pathogenesis and developing new therapies to optimize future treatment of hypertensive emergencies.
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Affiliation(s)
- Hiren P Patel
- Department of Pediatrics, Children's Hospital, The Ohio State University School of Medicine and Public Health, Columbus, Ohio, USA
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