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Papaioannou I, Dritsoula A, Kang P, Baliga RS, Trinder SL, Cook E, Shiwen X, Hobbs AJ, Denton CP, Abraham DJ, Ponticos M. NKX2-5 regulates vessel remodeling in scleroderma-associated pulmonary arterial hypertension. JCI Insight 2024; 9:e164191. [PMID: 38652537 DOI: 10.1172/jci.insight.164191] [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: 08/08/2022] [Accepted: 04/17/2024] [Indexed: 04/25/2024] Open
Abstract
NKX2-5 is a member of the homeobox-containing transcription factors critical in regulating tissue differentiation in development. Here, we report a role for NKX2-5 in vascular smooth muscle cell phenotypic modulation in vitro and in vascular remodeling in vivo. NKX2-5 is upregulated in scleroderma patients with pulmonary arterial hypertension. Suppression of NKX2-5 expression in smooth muscle cells halted vascular smooth muscle proliferation and migration, enhanced contractility, and blocked the expression of extracellular matrix genes. Conversely, overexpression of NKX2-5 suppressed the expression of contractile genes (ACTA2, TAGLN, CNN1) and enhanced the expression of matrix genes (COL1) in vascular smooth muscle cells. In vivo, conditional deletion of NKX2-5 attenuated blood vessel remodeling and halted the progression to hypertension in a mouse chronic hypoxia model. This study revealed that signals related to injury such as serum and low confluence, which induce NKX2-5 expression in cultured cells, is potentiated by TGF-β and further enhanced by hypoxia. The effect of TGF-β was sensitive to ERK5 and PI3K inhibition. Our data suggest a pivotal role for NKX2-5 in the phenotypic modulation of smooth muscle cells during pathological vascular remodeling and provide proof of concept for therapeutic targeting of NKX2-5 in vasculopathies.
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MESH Headings
- Animals
- Mice
- Homeobox Protein Nkx-2.5/genetics
- Homeobox Protein Nkx-2.5/metabolism
- Humans
- Vascular Remodeling/genetics
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Male
- Scleroderma, Systemic/pathology
- Scleroderma, Systemic/complications
- Scleroderma, Systemic/metabolism
- Scleroderma, Systemic/genetics
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/pathology
- Pulmonary Arterial Hypertension/metabolism
- Pulmonary Arterial Hypertension/genetics
- Pulmonary Arterial Hypertension/pathology
- Pulmonary Arterial Hypertension/etiology
- Female
- Transforming Growth Factor beta/metabolism
- Disease Models, Animal
- Cell Proliferation/genetics
- Middle Aged
- Hypertension, Pulmonary/metabolism
- Hypertension, Pulmonary/genetics
- Hypertension, Pulmonary/etiology
- Hypertension, Pulmonary/pathology
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Affiliation(s)
- Ioannis Papaioannou
- Division of Medicine, Department of Inflammation, University College London, Royal Free Campus, London, United Kingdom
| | - Athina Dritsoula
- Division of Medicine, Department of Inflammation, University College London, Royal Free Campus, London, United Kingdom
| | - Ping Kang
- Division of Medicine, Department of Inflammation, University College London, Royal Free Campus, London, United Kingdom
| | - Reshma S Baliga
- William Harvey Research Institute, Barts and The London School of Medicine & Dentistry, Queen Mary University of London, Charterhouse Square, London, United Kingdom
| | - Sarah L Trinder
- Division of Medicine, Department of Inflammation, University College London, Royal Free Campus, London, United Kingdom
| | - Emma Cook
- Division of Medicine, Department of Inflammation, University College London, Royal Free Campus, London, United Kingdom
| | - Xu Shiwen
- Division of Medicine, Department of Inflammation, University College London, Royal Free Campus, London, United Kingdom
| | - Adrian J Hobbs
- William Harvey Research Institute, Barts and The London School of Medicine & Dentistry, Queen Mary University of London, Charterhouse Square, London, United Kingdom
| | - Christopher P Denton
- Division of Medicine, Department of Inflammation, University College London, Royal Free Campus, London, United Kingdom
| | - David J Abraham
- Division of Medicine, Department of Inflammation, University College London, Royal Free Campus, London, United Kingdom
| | - Markella Ponticos
- Division of Medicine, Department of Inflammation, University College London, Royal Free Campus, London, United Kingdom
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2
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Halpage J, DaSilva Pantoja P, Mancarella S. Prolonged tamoxifen-enriched diet is associated with cardiomyopathy and nutritional frailty in mice. Exp Physiol 2024; 109:513-523. [PMID: 38291801 PMCID: PMC10984784 DOI: 10.1113/ep091668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 01/01/2024] [Indexed: 02/01/2024]
Abstract
Tamoxifen (TAM) is required for gene recombination in the inducible Cre/lox system. The TAM-enriched diet is considered safe, with negligible impact on animal wellbeing. However, studies reporting the long-term effects of the TAM diet and its potential impact on experimental outcomes are scarce. We conducted a longitudinal study on mice exposed to a 4-week dietary TAM citrate supplementation. Several parameters were recorded, such as body weight, body composition, mortality, and cardiac function. The collagen1a2 (Col1a2) transgenic mouse was used to assess TAM-induced recombination in vivo in cardiac fibroblasts followed by myocardial infarction (MI). The impact of TAM on the MI outcome was also evaluated. The recombination efficiency and cytotoxic effect of the TAM active metabolite, 4-hydroxy-tamoxifen (4-OHT), were assessed in vitro. Mice exposed to a TAM diet showed body weight loss and a 10% increase in mortality (P = 0.045). The TAM diet decreased cardiac function and induced cardiac remodeling, indicated by decreased fractional shortening from 32.23% to 19.23% (P = 0.001) and left ventricular (LV) wall thinning. All measured parameters were reversed to normal when mice were returned to a normal diet. Infarcted Col1a2-CreER mice on the TAM regimen showed gene recombination in fibroblasts, but it was associated with a substantial increase in mortality post-surgery (2.5-fold) compared to the controls. In vitro, 4-OHT induced gene editing in fibroblasts; however, cell growth arrest and cytotoxicity were observed at high concentrations. In conclusion, prolonged exposure to the TAM diet can be detrimental and necessitates careful model selection and interpretation of the results.
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Affiliation(s)
- Janith Halpage
- Department of PhysiologyUniversity of Tennessee Health Sciences CenterMemphisTennesseeUSA
| | | | - Salvatore Mancarella
- Department of PhysiologyUniversity of Tennessee Health Sciences CenterMemphisTennesseeUSA
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Dalla C, Jaric I, Pavlidi P, Hodes GE, Kokras N, Bespalov A, Kas MJ, Steckler T, Kabbaj M, Würbel H, Marrocco J, Tollkuhn J, Shansky R, Bangasser D, Becker JB, McCarthy M, Ferland-Beckham C. Practical solutions for including sex as a biological variable (SABV) in preclinical neuropsychopharmacological research. J Neurosci Methods 2024; 401:110003. [PMID: 37918446 PMCID: PMC10842858 DOI: 10.1016/j.jneumeth.2023.110003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/13/2023] [Accepted: 10/27/2023] [Indexed: 11/04/2023]
Abstract
Recently, many funding agencies have released guidelines on the importance of considering sex as a biological variable (SABV) as an experimental factor, aiming to address sex differences and avoid possible sex biases to enhance the reproducibility and translational relevance of preclinical research. In neuroscience and pharmacology, the female sex is often omitted from experimental designs, with researchers generalizing male-driven outcomes to both sexes, risking a biased or limited understanding of disease mechanisms and thus potentially ineffective therapeutics. Herein, we describe key methodological aspects that should be considered when sex is factored into in vitro and in vivo experiments and provide practical knowledge for researchers to incorporate SABV into preclinical research. Both age and sex significantly influence biological and behavioral processes due to critical changes at different timepoints of development for males and females and due to hormonal fluctuations across the rodent lifespan. We show that including both sexes does not require larger sample sizes, and even if sex is included as an independent variable in the study design, a moderate increase in sample size is sufficient. Moreover, the importance of tracking hormone levels in both sexes and the differentiation between sex differences and sex-related strategy in behaviors are explained. Finally, the lack of robust data on how biological sex influences the pharmacokinetic (PK), pharmacodynamic (PD), or toxicological effects of various preclinically administered drugs to animals due to the exclusion of female animals is discussed, and methodological strategies to enhance the rigor and translational relevance of preclinical research are proposed.
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Affiliation(s)
- Christina Dalla
- Department of Pharmacology, Medical School, National and Kapodistrian University of Athens, Greece.
| | - Ivana Jaric
- Animal Welfare Division, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Pavlina Pavlidi
- Department of Pharmacology, Medical School, National and Kapodistrian University of Athens, Greece
| | - Georgia E Hodes
- School of Neuroscience, Virginia Tech, Blacksburg, VA 24060, USA
| | - Nikolaos Kokras
- Department of Pharmacology, Medical School, National and Kapodistrian University of Athens, Greece; First Department of Psychiatry, Eginition Hospital, Medical School, National and Kapodistrian University of Athens, Greece
| | - Anton Bespalov
- Partnership for Assessment and Accreditation of Scientific Practice (PAASP GmbH), Heidelberg, Germany
| | - Martien J Kas
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, the Netherlands
| | | | - Mohamed Kabbaj
- Department of Biomedical Sciences & Neurosciences, College of Medicine, Florida State University, USA
| | - Hanno Würbel
- Animal Welfare Division, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Jordan Marrocco
- Department of Biology, Touro University, New York, NY 10027, USA
| | | | - Rebecca Shansky
- Department of Psychology, Northeastern University, Boston, MA 02128, USA
| | - Debra Bangasser
- Neuroscience Institute, Georgia State University, Atlanta, GA 30303, USA; Center for Behavioral Neuroscience, Georgia State University, Atlanta, GA 30303, USA
| | - Jill B Becker
- Department of Psychology and Michigan Neuroscience Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Margaret McCarthy
- University of Maryland School of Medicine, Department of Pharmacology, Baltimore MD, USA
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4
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Akiyama T, Sadahiro T, Yamada Y, Fujita R, Abe Y, Nakano K, Honda S, Ema M, Kubota Y, Sakai S, Hizawa N, Ieda M. Flk1 Deficiency and Hypoxia Synergistically Promote Endothelial Dysfunction, Vascular Remodeling, and Pulmonary Hypertension. Arterioscler Thromb Vasc Biol 2023; 43:1668-1683. [PMID: 37534464 DOI: 10.1161/atvbaha.123.319266] [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: 03/08/2023] [Accepted: 07/11/2023] [Indexed: 08/04/2023]
Abstract
BACKGROUND The mechanisms underlying pulmonary hypertension (PH) remain largely unknown; further, why advanced vascular remodeling preferentially occurs in arterioles is yet to be answered. VEGF (vascular endothelial growth factor) regulates angiogenesis through Flk1 (fetal liver kinase 1) and Flt1 (fms-like tyrosine kinase 1) on endothelial cells (ECs), which may be related to PH pathogenesis. However, spatiotemporal expression patterns of Flk1 and Flt1 in the pulmonary vascular system and the role of endothelial Flk1 in PH development remain poorly understood. METHODS We analyzed multiple reporter mice, including Flk1-GFP (green fluorescent protein) bacterial artificial chromosome transgenic (Tg), Flt1-DsRed bacterial artificial chromosome Tg, and Flk1-GFP/Flt1-DsRed double Tg mice, to determine the spatiotemporal expression of Flk1 and Flt1 in hypoxia-induced PH. We also used Cdh5CreERT2/Flk1f/f/Tomato (Flk1-KO [knockout]) mice to induce EC-specific Flk1 deletion and lineage tracing in chronic hypoxia. RESULTS Flk1 was specifically expressed in the ECs of small pulmonary vessels, including arterioles. Conversely, Flt1 was more broadly expressed in the ECs of large- to small-sized vessels in adult mouse lungs. Intriguingly, Flk1+ ECs were transiently increased in hypoxia with proliferation, whereas Flt1 expression was unchanged. Flk1-KO mice did not exhibit pulmonary vascular remodeling nor PH in normoxia; however, the arteriolar ECs changed to a cuboidal shape with protrusion. In hypoxia, Flk1 deletion exacerbated EC dysfunction and reduced their number via apoptosis. Additionally, Flk1 deletion promoted medial thickening and neointimal formation in arterioles and worsened PH. Mechanistically, lineage tracing revealed that neointimal cells were derived from Flk1-KO ECs. Moreover, RNA sequencing in pulmonary ECs demonstrated that Flk1 deletion and hypoxia synergistically activated multiple pathways, including cell cycle, senescence/apoptosis, and cytokine/growth factor, concomitant with suppression of cell adhesion and angiogenesis, to promote vascular remodeling. CONCLUSIONS Flk1 and Flt1 were differentially expressed in pulmonary ECs. Flk1 deficiency and hypoxia jointly dysregulated arteriolar ECs to promote vascular remodeling. Thus, dysfunction of Flk1+ ECs may contribute to the pathogenesis of advanced vascular remodeling in pulmonary arterioles.
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Affiliation(s)
- Tatsuya Akiyama
- Department of Cardiology (T.A., T.S., Y.Y., R.F., Y.A., K.N., S.H., S.S., M.I.), Institute of Medicine, University of Tsukuba, Ibaraki, Japan
- Department of Respiratory Medicine (T.A., N.H.), Institute of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Taketaro Sadahiro
- Department of Cardiology (T.A., T.S., Y.Y., R.F., Y.A., K.N., S.H., S.S., M.I.), Institute of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Yu Yamada
- Department of Cardiology (T.A., T.S., Y.Y., R.F., Y.A., K.N., S.H., S.S., M.I.), Institute of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Ryo Fujita
- Department of Cardiology (T.A., T.S., Y.Y., R.F., Y.A., K.N., S.H., S.S., M.I.), Institute of Medicine, University of Tsukuba, Ibaraki, Japan
- Division of Regenerative Medicine, Transborder Medical Research Center (R.F.), Institute of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Yuto Abe
- Department of Cardiology (T.A., T.S., Y.Y., R.F., Y.A., K.N., S.H., S.S., M.I.), Institute of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Koji Nakano
- Department of Cardiology (T.A., T.S., Y.Y., R.F., Y.A., K.N., S.H., S.S., M.I.), Institute of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Seiichiro Honda
- Department of Cardiology (T.A., T.S., Y.Y., R.F., Y.A., K.N., S.H., S.S., M.I.), Institute of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Masatsugu Ema
- Division of Regenerative Medicine, Transborder Medical Research Center (R.F.), Institute of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Yoshiaki Kubota
- Departments of Anatomy (Y.K.), Keio University School of Medicine, Tokyo, Japan
| | - Satoshi Sakai
- Department of Cardiology (T.A., T.S., Y.Y., R.F., Y.A., K.N., S.H., S.S., M.I.), Institute of Medicine, University of Tsukuba, Ibaraki, Japan
- Faculty of Health Science, Tsukuba University of Technology, Japan (S.S.)
| | - Nobuyuki Hizawa
- Department of Respiratory Medicine (T.A., N.H.), Institute of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Masaki Ieda
- Department of Cardiology (T.A., T.S., Y.Y., R.F., Y.A., K.N., S.H., S.S., M.I.), Institute of Medicine, University of Tsukuba, Ibaraki, Japan
- Cardiology (M.I.), Keio University School of Medicine, Tokyo, Japan
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5
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Leduc-Gaudet JP, Miguez K, Cefis M, Faitg J, Moamer A, Chaffer TJ, Reynaud O, Broering FE, Shams A, Mayaki D, Huck L, Sandri M, Gouspillou G, Hussain SN. Autophagy ablation in skeletal muscles worsens sepsis-induced muscle wasting, impairs whole-body metabolism, and decreases survival. iScience 2023; 26:107475. [PMID: 37588163 PMCID: PMC10425945 DOI: 10.1016/j.isci.2023.107475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 05/18/2023] [Accepted: 07/21/2023] [Indexed: 08/18/2023] Open
Abstract
Septic patients frequently develop skeletal muscle wasting and weakness, resulting in severe clinical consequences and adverse outcomes. Sepsis triggers sustained induction of autophagy, a key cellular degradative pathway, in skeletal muscles. However, the impact of enhanced autophagy on sepsis-induced muscle dysfunction remains unclear. Using an inducible and muscle-specific Atg7 knockout mouse model (Atg7iSkM-KO), we investigated the functional importance of skeletal muscle autophagy in sepsis using the cecal ligation and puncture model. Atg7iSkM-KO mice exhibited a more severe phenotype in response to sepsis, marked by severe muscle wasting, hypoglycemia, higher ketone levels, and a decreased in survival as compared to mice with intact Atg7. Sepsis and Atg7 deletion resulted in the accumulation of mitochondrial dysfunction, although sepsis did not further worsen mitochondrial dysfunction in Atg7iSkM-KO mice. Overall, our study demonstrates that autophagy inactivation in skeletal muscles triggers significant worsening of sepsis-induced muscle and metabolic dysfunctions and negatively impacts survival.
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Affiliation(s)
- Jean-Philippe Leduc-Gaudet
- Research Group in Cellular Signaling, Department of Medical Biology, Université du Québec À Trois-Rivières, Trois-Rivières, QC G9A 5H7, Canada
- Department of Critical Care and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre (MUHC), Montréal, QC H3H 2R9, Canada
- Meakins-Christie Laboratories, Department of Medicine, Faculty of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
- Département des sciences de l’activité physique, Faculté des sciences, Université du Québec à Montréal (UQAM), Montréal, QC H2X 1Y4, Canada
| | - Kayla Miguez
- Department of Critical Care and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre (MUHC), Montréal, QC H3H 2R9, Canada
- Meakins-Christie Laboratories, Department of Medicine, Faculty of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
| | - Marina Cefis
- Meakins-Christie Laboratories, Department of Medicine, Faculty of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
- Département des sciences de l’activité physique, Faculté des sciences, Université du Québec à Montréal (UQAM), Montréal, QC H2X 1Y4, Canada
| | - Julie Faitg
- Département des sciences de l’activité physique, Faculté des sciences, Université du Québec à Montréal (UQAM), Montréal, QC H2X 1Y4, Canada
- Amazentis SA, EPFL Innovation Park, 1015 Lausanne, Switzerland
| | - Alaa Moamer
- Meakins-Christie Laboratories, Department of Medicine, Faculty of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
| | - Tomer Jordi Chaffer
- Department of Critical Care and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre (MUHC), Montréal, QC H3H 2R9, Canada
- Meakins-Christie Laboratories, Department of Medicine, Faculty of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
| | - Olivier Reynaud
- Département des sciences de l’activité physique, Faculté des sciences, Université du Québec à Montréal (UQAM), Montréal, QC H2X 1Y4, Canada
| | - Felipe E. Broering
- Department of Critical Care and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre (MUHC), Montréal, QC H3H 2R9, Canada
- Meakins-Christie Laboratories, Department of Medicine, Faculty of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
| | - Anwar Shams
- Department of Pharmacology, Faculty of Medicine, Taif University, P.O.BOX 11099, Taif 21944, Saudi Arabia
| | - Dominique Mayaki
- Department of Critical Care and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre (MUHC), Montréal, QC H3H 2R9, Canada
- Meakins-Christie Laboratories, Department of Medicine, Faculty of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
| | - Laurent Huck
- Department of Critical Care and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre (MUHC), Montréal, QC H3H 2R9, Canada
- Meakins-Christie Laboratories, Department of Medicine, Faculty of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
| | - Marco Sandri
- Meakins-Christie Laboratories, Department of Medicine, Faculty of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
- Veneto Institute of Molecular Medicine (VIMM) and Department of Biomedical Science, Università di Padova, 35129 Padova, Italy
| | - Gilles Gouspillou
- Meakins-Christie Laboratories, Department of Medicine, Faculty of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
- Département des sciences de l’activité physique, Faculté des sciences, Université du Québec à Montréal (UQAM), Montréal, QC H2X 1Y4, Canada
| | - Sabah N.A. Hussain
- Department of Critical Care and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre (MUHC), Montréal, QC H3H 2R9, Canada
- Meakins-Christie Laboratories, Department of Medicine, Faculty of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
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Díaz Del Moral S, Benaouicha M, Villa Del Campo C, Torres M, Wagner N, Wagner KD, Muñoz-Chápuli R, Carmona R. Cardiomyocyte-Specific Wt1 Is Involved in Cardiac Metabolism and Response to Damage. J Cardiovasc Dev Dis 2023; 10:jcdd10050211. [PMID: 37233178 DOI: 10.3390/jcdd10050211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 04/23/2023] [Accepted: 05/09/2023] [Indexed: 05/27/2023] Open
Abstract
The Wilms tumor suppressor gene (Wt1) encodes a C2H2-type zinc-finger transcription factor that participates in transcriptional regulation, RNA metabolism, and protein-protein interactions. WT1 is involved in the development of several organs, including the kidneys and gonads, heart, spleen, adrenal glands, liver, diaphragm, and neuronal system. We previously provided evidence of transient WT1 expression in about 25% of cardiomyocytes of mouse embryos. Conditional deletion of Wt1 in the cardiac troponin T lineage caused abnormal cardiac development. A low expression of WT1 has also been reported in adult cardiomyocytes. Therefore, we aimed to explore its function in cardiac homeostasis and in the response to pharmacologically induced damage. Silencing of Wt1 in cultured neonatal murine cardiomyocytes provoked alterations in mitochondrial membrane potential and changes in the expression of genes related to calcium homeostasis. Ablation of WT1 in adult cardiomyocytes by crossing αMHCMerCreMer mice with homozygous WT1-floxed mice induced hypertrophy, interstitial fibrosis, altered metabolism, and mitochondrial dysfunction. In addition, conditional deletion of WT1 in adult cardiomyocytes increased doxorubicin-induced damage. These findings suggest a novel role of WT1 in myocardial physiology and protection against damage.
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Affiliation(s)
- Sandra Díaz Del Moral
- Department of Animal Biology, Faculty of Science, University of Málaga, 29071 Málaga, Spain
| | - Maha Benaouicha
- Department of Cell Biology, Genetics and Physiology, Faculty of Science, University of Málaga, 29071 Málaga, Spain
| | - Cristina Villa Del Campo
- Cardiovascular Development Program, Centro Nacional de Investigaciones Cardiovasculares, CNIC, 28029 Madrid, Spain
| | - Miguel Torres
- Cardiovascular Development Program, Centro Nacional de Investigaciones Cardiovasculares, CNIC, 28029 Madrid, Spain
| | - Nicole Wagner
- Université Côte d'Azur, CNRS, INSERM, iBV, 06108 Nice, France
| | | | - Ramón Muñoz-Chápuli
- Department of Animal Biology, Faculty of Science, University of Málaga, 29071 Málaga, Spain
| | - Rita Carmona
- Department of Human Anatomy, Legal Medicine and History of Science, Faculty of Medicine, University of Málaga, 29071 Málaga, Spain
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7
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Goodwin AT, John AE, Joseph C, Habgood A, Tatler AL, Susztak K, Palmer M, Offermanns S, Henderson NC, Jenkins RG. Stretch regulates alveologenesis and homeostasis via mesenchymal Gαq/11-mediated TGFβ2 activation. Development 2023; 150:dev201046. [PMID: 37102682 PMCID: PMC10259661 DOI: 10.1242/dev.201046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 04/05/2023] [Indexed: 04/28/2023]
Abstract
Alveolar development and repair require tight spatiotemporal regulation of numerous signalling pathways that are influenced by chemical and mechanical stimuli. Mesenchymal cells play key roles in numerous developmental processes. Transforming growth factor-β (TGFβ) is essential for alveologenesis and lung repair, and the G protein α subunits Gαq and Gα11 (Gαq/11) transmit mechanical and chemical signals to activate TGFβ in epithelial cells. To understand the role of mesenchymal Gαq/11 in lung development, we generated constitutive (Pdgfrb-Cre+/-;Gnaqfl/fl;Gna11-/-) and inducible (Pdgfrb-Cre/ERT2+/-;Gnaqfl/fl;Gna11-/-) mesenchymal Gαq/11 deleted mice. Mice with constitutive Gαq/11 gene deletion exhibited abnormal alveolar development, with suppressed myofibroblast differentiation, altered mesenchymal cell synthetic function, and reduced lung TGFβ2 deposition, as well as kidney abnormalities. Tamoxifen-induced mesenchymal Gαq/11 gene deletion in adult mice resulted in emphysema associated with reduced TGFβ2 and elastin deposition. Cyclical mechanical stretch-induced TGFβ activation required Gαq/11 signalling and serine protease activity, but was independent of integrins, suggesting an isoform-specific role for TGFβ2 in this model. These data highlight a previously undescribed mechanism of cyclical stretch-induced Gαq/11-dependent TGFβ2 signalling in mesenchymal cells, which is imperative for normal alveologenesis and maintenance of lung homeostasis.
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Affiliation(s)
- Amanda T. Goodwin
- Centre for Respiratory Research, Translational Medical Sciences, School of Medicine, University of Nottingham, Nottingham, NG7 2RD, UK
- Respiratory Medicine, Nottingham NIHR Biomedical Research Centre, Nottingham, NG7 2RD, UK
- Respiratory Medicine, Biodiscovery Institute, University Park, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Alison E. John
- Margaret Turner Warwick Centre for Fibrosing Lung Disease, National Heart and Lung Institute, Imperial College London, London, SW3 6LY, UK
| | - Chitra Joseph
- Centre for Respiratory Research, Translational Medical Sciences, School of Medicine, University of Nottingham, Nottingham, NG7 2RD, UK
- Respiratory Medicine, Nottingham NIHR Biomedical Research Centre, Nottingham, NG7 2RD, UK
- Respiratory Medicine, Biodiscovery Institute, University Park, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Anthony Habgood
- Centre for Respiratory Research, Translational Medical Sciences, School of Medicine, University of Nottingham, Nottingham, NG7 2RD, UK
- Respiratory Medicine, Nottingham NIHR Biomedical Research Centre, Nottingham, NG7 2RD, UK
- Respiratory Medicine, Biodiscovery Institute, University Park, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Amanda L. Tatler
- Centre for Respiratory Research, Translational Medical Sciences, School of Medicine, University of Nottingham, Nottingham, NG7 2RD, UK
- Respiratory Medicine, Nottingham NIHR Biomedical Research Centre, Nottingham, NG7 2RD, UK
- Respiratory Medicine, Biodiscovery Institute, University Park, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Katalin Susztak
- Department of Medicine, Division of Nephrology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Matthew Palmer
- Department of Pathology, Division of Nephrology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104-4238, USA
| | - Stefan Offermanns
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Neil C. Henderson
- Centre for Inflammation Research, University of Edinburgh, EH16 4TJ, UK
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, EH4 2XU, UK
| | - R. Gisli Jenkins
- Margaret Turner Warwick Centre for Fibrosing Lung Disease, National Heart and Lung Institute, Imperial College London, London, SW3 6LY, UK
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8
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Xie Y, Zhou J, Wang LL, Zhang CL, Chen B. New AAV tools fail to detect Neurod1-mediated neuronal conversion of Müller glia and astrocytes in vivo. EBioMedicine 2023; 90:104531. [PMID: 36947961 PMCID: PMC10033723 DOI: 10.1016/j.ebiom.2023.104531] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 03/03/2023] [Accepted: 03/03/2023] [Indexed: 03/24/2023] Open
Abstract
BACKGROUND Reprogramming resident glial cells to convert them into neurons in vivo represents a potential therapeutic strategy that could replenish lost neurons, repair damaged neural circuits, and restore function. AAV (adeno-associated virus)-based expression systems are powerful tools for in vivo gene delivery in glia-to-neuron reprogramming, however, recent studies show that AAV-based gene delivery of Neurod1 into the mouse brain can cause severe leaky expression into endogenous neurons leading to misinterpretation of glia-to-neuron conversion. METHODS AAV-based delivery systems were modified for improved in vivo delivery of Neurod1, Math5, Ascl1, and Neurog2 in the adult mouse retina and brain. To examine whether bona fide glia-to-neuron conversion occurs, stringent fate mapping experiments were performed to trace the lineage of glial cells. FINDINGS The neuronal leakage is prevalent after AAV-GFAP-mediated delivery of Neurod1, Math5, Ascl1, and Neurog2. The transgene-dependent leakage cannot be corrected after lowering the AAV doses, using alterative AAV serotypes or injection routes. Importantly, we report the development of two new AAV-based tools that can significantly reduce neuronal leakage. Using the new AAV-based tools, we provide evidence that Neurod1 gene transfer fails to convert lineage traced glial cells into neurons. INTERPRETATION Stringent fate mapping techniques independently of an AAV-based expression system are the golden standard for tracing the fate of glia cells during neuronal reprogramming. The newly developed AAV-based systems are invaluable tools for glia-to-neuron reprogramming in vivo. FUNDING The work in Chen lab was supported by National Institutes of Health (NIH) grants R01 EY024986 and R01 EY028921, an unrestricted challenge grant from Research to Prevent Blindness, the New York Eye and Ear Infirmary Foundation, and The Harold W. McGraw, Jr. Family Foundation for Vision Research. The work in Zhang lab was supported by NIH (R01 NS127375 and R01 NS117065) and The Decherd Foundation.
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Affiliation(s)
- Ye Xie
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Jing Zhou
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Lei-Lei Wang
- Department of Molecular Biology and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Chun-Li Zhang
- Department of Molecular Biology and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Bo Chen
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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9
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Wang L, Moonen JR, Cao A, Isobe S, Li CG, Tojais NF, Taylor S, Marciano DP, Chen PI, Gu M, Li D, Harper RL, El-Bizri N, Kim Y, Stankunas K, Rabinovitch M. Dysregulated Smooth Muscle Cell BMPR2-ARRB2 Axis Causes Pulmonary Hypertension. Circ Res 2023; 132:545-564. [PMID: 36744494 PMCID: PMC10008520 DOI: 10.1161/circresaha.121.320541] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 01/26/2023] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Mutations in BMPR2 (bone morphogenetic protein receptor 2) are associated with familial and sporadic pulmonary arterial hypertension (PAH). The functional and molecular link between loss of BMPR2 in pulmonary artery smooth muscle cells (PASMC) and PAH pathogenesis warrants further investigation, as most investigations focus on BMPR2 in pulmonary artery endothelial cells. Our goal was to determine whether and how decreased BMPR2 is related to the abnormal phenotype of PASMC in PAH. METHODS SMC-specific Bmpr2-/- mice (BKOSMC) were created and compared to controls in room air, after 3 weeks of hypoxia as a second hit, and following 4 weeks of normoxic recovery. Echocardiography, right ventricular systolic pressure, and right ventricular hypertrophy were assessed as indices of pulmonary hypertension. Proliferation, contractility, gene and protein expression of PASMC from BKOSMC mice, human PASMC with BMPR2 reduced by small interference RNA, and PASMC from PAH patients with a BMPR2 mutation were compared to controls, to investigate the phenotype and underlying mechanism. RESULTS BKOSMC mice showed reduced hypoxia-induced vasoconstriction and persistent pulmonary hypertension following recovery from hypoxia, associated with sustained muscularization of distal pulmonary arteries. PASMC from mutant compared to control mice displayed reduced contractility at baseline and in response to angiotensin II, increased proliferation and apoptosis resistance. Human PASMC with reduced BMPR2 by small interference RNA, and PASMC from PAH patients with a BMPR2 mutation showed a similar phenotype related to upregulation of pERK1/2 (phosphorylated extracellular signal related kinase 1/2)-pP38-pSMAD2/3 mediating elevation in ARRB2 (β-arrestin2), pAKT (phosphorylated protein kinase B) inactivation of GSK3-beta, CTNNB1 (β-catenin) nuclear translocation and reduction in RHOA (Ras homolog family member A) and RAC1 (Ras-related C3 botulinum toxin substrate 1). Decreasing ARRB2 in PASMC with reduced BMPR2 restored normal signaling, reversed impaired contractility and attenuated heightened proliferation and in mice with inducible loss of BMPR2 in SMC, decreasing ARRB2 prevented persistent pulmonary hypertension. CONCLUSIONS Agents that neutralize the elevated ARRB2 resulting from loss of BMPR2 in PASMC could prevent or reverse the aberrant hypocontractile and hyperproliferative phenotype of these cells in PAH.
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Affiliation(s)
- Lingli Wang
- BASE Initiative, Betty Irene Moore Children’s Heart Center, Lucile Packard Children’s Hospital
- Vera Moulton Wall Center for Pulmonary Vascular Diseases, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
- Department of Pediatrics (Cardiology), Stanford University School of Medicine, Stanford, CA, USA
| | - Jan Renier Moonen
- BASE Initiative, Betty Irene Moore Children’s Heart Center, Lucile Packard Children’s Hospital
- Vera Moulton Wall Center for Pulmonary Vascular Diseases, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
- Department of Pediatrics (Cardiology), Stanford University School of Medicine, Stanford, CA, USA
| | - Aiqin Cao
- BASE Initiative, Betty Irene Moore Children’s Heart Center, Lucile Packard Children’s Hospital
- Vera Moulton Wall Center for Pulmonary Vascular Diseases, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
- Department of Pediatrics (Cardiology), Stanford University School of Medicine, Stanford, CA, USA
| | - Sarasa Isobe
- BASE Initiative, Betty Irene Moore Children’s Heart Center, Lucile Packard Children’s Hospital
- Vera Moulton Wall Center for Pulmonary Vascular Diseases, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
- Department of Pediatrics (Cardiology), Stanford University School of Medicine, Stanford, CA, USA
| | - Caiyun G Li
- Vera Moulton Wall Center for Pulmonary Vascular Diseases, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
- Department of Pediatrics (Cardiology), Stanford University School of Medicine, Stanford, CA, USA
| | - Nancy F Tojais
- Vera Moulton Wall Center for Pulmonary Vascular Diseases, Stanford University School of Medicine, Stanford, CA, USA
- Department of Pediatrics (Cardiology), Stanford University School of Medicine, Stanford, CA, USA
| | - Shalina Taylor
- Vera Moulton Wall Center for Pulmonary Vascular Diseases, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
- Department of Pediatrics (Cardiology), Stanford University School of Medicine, Stanford, CA, USA
| | - David P Marciano
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Pin-I Chen
- Vera Moulton Wall Center for Pulmonary Vascular Diseases, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
- Department of Pediatrics (Cardiology), Stanford University School of Medicine, Stanford, CA, USA
| | - Mingxia Gu
- Vera Moulton Wall Center for Pulmonary Vascular Diseases, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
- Department of Pediatrics (Cardiology), Stanford University School of Medicine, Stanford, CA, USA
| | - Dan Li
- Vera Moulton Wall Center for Pulmonary Vascular Diseases, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
- Department of Pediatrics (Cardiology), Stanford University School of Medicine, Stanford, CA, USA
| | - Rebecca L Harper
- Vera Moulton Wall Center for Pulmonary Vascular Diseases, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
- Department of Pediatrics (Cardiology), Stanford University School of Medicine, Stanford, CA, USA
| | - Nesrine El-Bizri
- Vera Moulton Wall Center for Pulmonary Vascular Diseases, Stanford University School of Medicine, Stanford, CA, USA
- Department of Pediatrics (Cardiology), Stanford University School of Medicine, Stanford, CA, USA
| | - YuMee Kim
- Vera Moulton Wall Center for Pulmonary Vascular Diseases, Stanford University School of Medicine, Stanford, CA, USA
- Department of Pediatrics (Cardiology), Stanford University School of Medicine, Stanford, CA, USA
| | - Kryn Stankunas
- Departments of Pathology and of Developmental Biology, and Howard Hughes Medical Institute; Stanford University School of Medicine, Stanford, CA, USA
| | - Marlene Rabinovitch
- BASE Initiative, Betty Irene Moore Children’s Heart Center, Lucile Packard Children’s Hospital
- Vera Moulton Wall Center for Pulmonary Vascular Diseases, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
- Department of Pediatrics (Cardiology), Stanford University School of Medicine, Stanford, CA, USA
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10
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Tanaka T, Okuda H, Isonishi A, Terada Y, Kitabatake M, Shinjo T, Nishimura K, Takemura S, Furue H, Ito T, Tatsumi K, Wanaka A. Dermal macrophages set pain sensitivity by modulating the amount of tissue NGF through an SNX25-Nrf2 pathway. Nat Immunol 2023; 24:439-451. [PMID: 36703006 PMCID: PMC9977679 DOI: 10.1038/s41590-022-01418-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 12/16/2022] [Indexed: 01/27/2023]
Abstract
Cross-talk between peripheral neurons and immune cells is important in pain sensation. We identified Snx25 as a pain-modulating gene in a transgenic mouse line with reduced pain sensitivity. Conditional deletion of Snx25 in monocytes and macrophages, but not in peripheral sensory neurons, in mice (Snx25cKO mice) reduced pain responses in both normal and neuropathic conditions. Bone marrow transplantation using Snx25cKO and wild-type mice indicated that macrophages modulated pain sensitivity. Expression of sorting nexin (SNX)25 in dermal macrophages enhanced expression of the neurotrophic factor NGF through the inhibition of ubiquitin-mediated degradation of Nrf2, a transcription factor that activates transcription of Ngf. As such, dermal macrophages set the threshold for pain sensitivity through the production and secretion of NGF into the dermis, and they may cooperate with dorsal root ganglion macrophages in pain perception.
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Affiliation(s)
- Tatsuhide Tanaka
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Japan.
| | - Hiroaki Okuda
- Department of Functional Anatomy, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan
| | - Ayami Isonishi
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Japan
| | - Yuki Terada
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Japan
| | - Masahiro Kitabatake
- Department of Immunology, Faculty of Medicine, Nara Medical University, Kashihara, Japan
| | - Takeaki Shinjo
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Japan
| | - Kazuya Nishimura
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Japan
| | - Shoko Takemura
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Japan
| | - Hidemasa Furue
- Department of Neurophysiology, Hyogo College of Medicine, Nishinomiya, Japan
| | - Toshihiro Ito
- Department of Immunology, Faculty of Medicine, Nara Medical University, Kashihara, Japan
| | - Kouko Tatsumi
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Japan
| | - Akio Wanaka
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Japan.
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11
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Fu X, Huang YP, Lindeman S, Mago A, Fukunaga I. Dense and Sparse Labelling of Mitral Cells by Oral and Intraperitoneal Routes of Tamoxifen Administration. Methods Mol Biol 2023; 2710:185-193. [PMID: 37688733 DOI: 10.1007/978-1-0716-3425-7_14] [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] [Indexed: 09/11/2023]
Abstract
Cell type-specific labelling and manipulation using Cre-driver lines have become integral to analyses of neuronal circuits in the brain. To study how mitral cells of the olfactory bulb process olfactory information and how they contribute to behavior, an inducible Cre-driver line, Lbhd2-CreERT2, can be used. In this chapter, we describe two methods for administering tamoxifen. The first method achieves a dense recombination pattern using tamoxifen-containing food, while the second method involving an intraperitoneal injection is suited for sparse labelling.
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Affiliation(s)
- Xiaochen Fu
- Sensory and Behavioural Neuroscience Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Yu-Pei Huang
- Sensory and Behavioural Neuroscience Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Sander Lindeman
- Sensory and Behavioural Neuroscience Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Adam Mago
- Sensory and Behavioural Neuroscience Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Izumi Fukunaga
- Sensory and Behavioural Neuroscience Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan.
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12
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Kumar R, Mao Y, Patial S, Saini Y. Induction of whole-body gene deletion via R26-regulated tamoxifen-inducible Cre recombinase activity. Front Pharmacol 2022; 13:1018798. [PMID: 36569322 PMCID: PMC9772612 DOI: 10.3389/fphar.2022.1018798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 11/08/2022] [Indexed: 12/14/2022] Open
Abstract
Germline deletion of certain genes causes embryonic lethality, therefore, understanding the effect of deletion of such genes on mammalian pathophysiology remains challenging. Tamoxifen (TAM)-inducible Cre recombinase is widely used for tissue-specific and temporal induction of gene deletion in mice. However, the tamoxifen treatment regimen for the generation of whole-body deletion of a gene is not yet fully standardized for the majority of organs/tissues. Accordingly, we employed GtROSA26 (R26) promoter-regulated Cre and a reporter gene expression strategy. GtROSA26 (R26) is an ubiquitous promoter and mice carrying the R26Cre-ERT2 transgene express Cre-ERT2 in all the cells. Similarly, mice carrying the R26mTOM-mEGFP transgene express mTOM (membrane-targeted tdTomato), in the absence of Cre or mEGFP (membrane-targeted enhanced green fluorescent protein), in the presence of Cre, in all the cells. The progeny carrying one allele of both transgenes were subjected to different TAM regimens, i.e., IP injections (4 injections; 1.35 mg/injection), diet (400 mg TAM-citrate/kg food), or diet (400 mg TAM-citrate/kg food) combined with either TAM-oral gavage (4 gavages; 1.35 mg/gavage) or TAM IP injections (4 injections; 1.35 mg/injection) for 2-weeks beginning at postnatal day (PND) 21 and the extent of Cre recombination in different tissues was determined at PND35. Tamoxifen administration resulted in a transient loss of body weight in all the treatment regimens with a relatively slower rate of weight gain in the TAM-diet plus TAM-oral gavage group compared to other groups. While the efficiency of Cre recombination, as determined by the expression of mEGFP protein, was variable among tissues, major tissues such as the liver, heart, lungs, spleen, and thymus-showed almost complete recombination. No recombination was evident in any of the tissues examined from the control mice. In general, the efficiency of Cre recombination was better with a combined regimen of TAM-diet with either TAM-injections or TAM-oral gavage compared to TAM-diet alone or TAM-injections alone. Our results demonstrate that a combination of TAM-diet with either TAM-injections or TAM-oral gavage can be employed for the efficient deletion of a gene in the whole body. Our findings will provide technical expertise to the researchers employing TAM-inducible Cre for the deletion of floxed genes in varied tissues.
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13
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Modulation of Rxrα Expression in Mononuclear Phagocytes Impacts on Cardiac Remodeling after Ischemia-Reperfusion Injury. Biomedicines 2022; 10:biomedicines10061274. [PMID: 35740296 PMCID: PMC9219801 DOI: 10.3390/biomedicines10061274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 05/21/2022] [Accepted: 05/26/2022] [Indexed: 11/17/2022] Open
Abstract
Retinoid X receptors (RXRs), as members of the steroid/thyroid hormone superfamily of nuclear receptors, are crucial regulators of immune response during health and disease. RXR subtype expression is dependent on tissue and cell type, RXRα being the relevant isoform in monocytes and macrophages. Previous studies have assessed different functions of RXRs and positive implications of RXR agonists on outcomes after ischemic injuries have been described. However, the impact of a reduced Rxrα expression in mononuclear phagocytes on cardiac remodeling after myocardial infarction (MI) has not been investigated to date. Here, we use a temporally controlled deletion of Rxrα in monocytes and macrophages to determine its role in ischemia-reperfusion injury. We show that reduced expression of Rxrα in mononuclear phagocytes leads to a decreased phagocytic activity and an accumulation of apoptotic cells in the myocardium, reduces angiogenesis and cardiac macrophage proliferation in the infarct border zone/infarct area, and has an impact on monocyte/macrophage subset composition. These changes are associated with a greater myocardial defect 30 days after ischemia/reperfusion injury. Overall, the reduction of Rxrα levels in monocytes and macrophages negatively impacts cardiac remodeling after myocardial infarction. Thus, RXRα might represent a therapeutic target to regulate the immune response after MI in order to improve cardiac remodeling.
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14
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Functional IKK/NF-κB signaling in pancreatic stellate cells is essential to prevent autoimmune pancreatitis. Commun Biol 2022; 5:509. [PMID: 35624133 PMCID: PMC9142538 DOI: 10.1038/s42003-022-03371-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 04/14/2022] [Indexed: 01/07/2023] Open
Abstract
Pancreatic stellate cells (PSCs) are resident cells in the exocrine pancreas which contribute to pancreatic fibrogenesis and inflammation. Studies on NF-κB in pancreatitis so far focused mainly on the parenchymal and myeloid compartments. Here we show a protective immunomodulatory function of NF-κB in PSCs. Conditional deletion of NEMO (IKKγ) in PSCs leads to spontaneous pancreatitis with elevated circulating IgM, IgG and antinuclear autoantibodies (ANA) within 18 weeks. When further challenged with caerulein, NEMOΔCol1a2 mice show an exacerbated autoimmune phenotype characterized by increased infiltration of eosinophils, B and T lymphocytes with reduced latency period. Transcriptomic profiling shows that NEMOΔCol1a2 mice display molecular signatures resembling autoimmune pancreatitis patients. Mechanistically, we show that PSCΔNEMO cells produce high levels of CCL24 ex vivo which contributes to eosinophil recruitment, as neutralization with a CCL24 antibody abolishes the transwell migration of eosinophils. Our findings uncover an unexpected immunomodulatory role specifically of NF-κB in PSCs during pancreatitis. A model of autoimmune pancreatitis is developed by blocking the activation of NF-κB in pancreatic stellate cells, via conditional deletion of NEMO (IKKγ), which presents strong pancreatic inflammation with eosinophilia after the induction of chronic pancreatitis by repeated caerulein challenges.
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15
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Oral and Injected Tamoxifen Alter Adult Hippocampal Neurogenesis in Female and Male Mice. eNeuro 2022; 9:ENEURO.0422-21.2022. [PMID: 35387845 PMCID: PMC9034758 DOI: 10.1523/eneuro.0422-21.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 02/10/2022] [Accepted: 03/30/2022] [Indexed: 11/21/2022] Open
Abstract
Inducible Cre recombinase facilitates temporal control of genetic recombination in numerous transgenic model systems, a feature which has made it a popular tool for adult neurogenesis studies. One of the most common forms of inducible Cre, CreERT2, requires activation by the selective estrogen receptor modulator tamoxifen (TAM) to initiate recombination of LoxP-flanked sequences. To date, most studies deliver TAM via intraperitoneal injection. But the introduction of TAM-infused commercial chows has recently expanded the possible modes of TAM delivery. Despite the widespread use of TAM-inducible genetic models in adult neurogenesis research, the comparative efficiency and off-target effects of TAM administration protocols is surprisingly infrequently studied. Here, we compare a standard, 5 d TAM injection regimen with voluntary consumption of TAM-infused chow. First, we used adult NestinCreERT2;Rosa-LoxP-STOP-LoxP-EYFP reporter mice to show that two weeks of TAM chow and 5 d of injections led to LoxP recombination in a similar phenotypic population of neural stem and progenitor cells (NSPCs) in the adult dentate gyrus. However, TAM chow resulted in substantially less overall recombination than injections. TAM administration also altered adult neurogenesis, but in different ways depending on administration route: TAM injection disrupted neural progenitor cell proliferation three weeks after TAM, whereas TAM chow increased neuronal differentiation of cells generated during the diet period. These findings provide guidance for selection of TAM administration route and appropriate controls in adult neurogenesis studies using TAM-inducible Cre mice. They also highlight the need for better understanding of off-target effects of TAM in other neurologic processes and organ systems.
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16
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Blaszkiewicz M, Gunsch G, Willows JW, Gardner ML, Sepeda JA, Sas AR, Townsend KL. Adipose Tissue Myeloid-Lineage Neuroimmune Cells Express Genes Important for Neural Plasticity and Regulate Adipose Innervation. Front Endocrinol (Lausanne) 2022; 13:864925. [PMID: 35795142 PMCID: PMC9251313 DOI: 10.3389/fendo.2022.864925] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 05/05/2022] [Indexed: 12/19/2022] Open
Abstract
Peripheral nerves allow a bidirectional communication between brain and adipose tissues, and many studies have clearly demonstrated that a loss of the adipose nerve supply results in tissue dysfunction and metabolic dysregulation. Neuroimmune cells closely associate with nerves in many tissues, including subcutaneous white adipose tissue (scWAT). However, in scWAT, their functions beyond degrading norepinephrine in an obese state remain largely unexplored. We previously reported that a myeloid-lineage knockout (KO) of brain-derived neurotrophic factor (BDNF) resulted in decreased innervation of scWAT, accompanied by an inability to brown scWAT after cold stimulation, and increased adiposity after a high-fat diet. These data underscored that adipose tissue neuroimmune cells support the peripheral nerve supply to adipose and impact the tissue's metabolic functions. We also reported that a subset of myeloid-lineage monocyte/macrophages (Ly6c+CCR2+Cx3cr1+) is recruited to scWAT in response to cold, a process known to increase neurite density in adipose and promote metabolically healthy processes. These cold-induced neuroimmune cells (CINCs) also expressed BDNF. Here we performed RNAseq on CINCs from cold-exposed and room temperature-housed mice, which revealed a striking and coordinated differential expression of numerous genes involved in neuronal function, including neurotrophin signaling and axonal guidance, further supporting that CINCs fulfill a nerve-supporting role in adipose. The increased expression of leukocyte transendothelial migration genes in cold-stimulated CINCs also confirms prior evidence that they are recruited to scWAT and are not tissue resident. We now provide whole-depot imaging of scWAT from LysM-BDNF KO mice, revealing a striking reduction of innervation across the depot fitting with their reduced energy expenditure phenotype. By contrast, Cx3cr1-BDNF KO mice (a macrophage subset of LysM+ cells) exhibited increased thermogenesis and energy expenditure, with compensatory increased food intake and no change in adiposity or body weight. While these KO mice also exhibit a significantly reduced innervation of scWAT, especially around the subiliac lymph node, they displayed an increase in small fiber sympathetic neurite branching, which may underlie their increased thermogenesis. We propose a homeostatic role of scWAT myeloid-lineage neuroimmune cells together in nerve maintenance and neuro-adipose regulation of energy expenditure.
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Affiliation(s)
- Magdalena Blaszkiewicz
- Neurobiology and Energy Balance Laboratory, Department of Neurological Surgery, The Ohio State University, Wexner Medical Center, Columbus, OH, United States
| | - Gilian Gunsch
- Neurobiology and Energy Balance Laboratory, Department of Neurological Surgery, The Ohio State University, Wexner Medical Center, Columbus, OH, United States
| | - Jake W. Willows
- Neurobiology and Energy Balance Laboratory, Department of Neurological Surgery, The Ohio State University, Wexner Medical Center, Columbus, OH, United States
| | - Miranda L. Gardner
- Department of Cancer Biology and Genetics, Comprehensive Cancer Center, The Ohio State University, Wexner Medical Center, Columbus, OH, United States
- Campus Chemical Instrument Center, Mass Spectrometry and Proteomics Facility, The Ohio State University, Columbus, OH, United States
| | - Jesse A. Sepeda
- Department of Neurology, The Ohio State University, Wexner Medical Center, Columbus, OH, United States
| | - Andrew R. Sas
- Department of Neurology, The Ohio State University, Wexner Medical Center, Columbus, OH, United States
| | - Kristy L. Townsend
- Neurobiology and Energy Balance Laboratory, Department of Neurological Surgery, The Ohio State University, Wexner Medical Center, Columbus, OH, United States
- *Correspondence: Kristy L. Townsend,
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17
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Terzic B, Davatolhagh MF, Ho Y, Tang S, Liu YT, Xia Z, Cui Y, Fuccillo MV, Zhou Z. Temporal manipulation of Cdkl5 reveals essential postdevelopmental functions and reversible CDKL5 deficiency disorder-related deficits. J Clin Invest 2021; 131:143655. [PMID: 34651584 DOI: 10.1172/jci143655] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 08/05/2021] [Indexed: 12/23/2022] Open
Abstract
CDKL5 deficiency disorder (CDD) is an early onset, neurodevelopmental syndrome associated with pathogenic variants in the X-linked gene encoding cyclin-dependent kinase-like 5 (CDKL5). CDKL5 has been implicated in neuronal synapse maturation, yet its postdevelopmental necessity and the reversibility of CDD-associated impairments remain unknown. We temporally manipulated endogenous Cdkl5 expression in male mice and found that postdevelopmental loss of CDKL5 disrupts numerous behavioral domains, hippocampal circuit communication, and dendritic spine morphology, demonstrating an indispensable role for CDKL5 in the adult brain. Accordingly, restoration of Cdkl5 after the early stages of brain development using a conditional rescue mouse model ameliorated CDD-related behavioral impairments and aberrant NMDA receptor signaling. These findings highlight the requirement of CDKL5 beyond early development, underscore the potential for disease reversal in CDD, and suggest that a broad therapeutic time window exists for potential treatment of CDD-related deficits.
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Affiliation(s)
| | - M Felicia Davatolhagh
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | | | | | | | | | - Marc V Fuccillo
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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18
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Heinen A, Gödecke S, Flögel U, Miklos D, Bottermann K, Spychala A, Gödecke A. 4-hydroxytamoxifen does not deteriorate cardiac function in cardiomyocyte-specific MerCreMer transgenic mice. Basic Res Cardiol 2021; 116:8. [PMID: 33544211 PMCID: PMC7864833 DOI: 10.1007/s00395-020-00841-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 12/28/2020] [Indexed: 01/28/2023]
Abstract
Conditional, cell-type-specific transgenic mouse lines are of high value in cardiovascular research. A standard tool for cardiomyocyte-restricted DNA editing is the αMHC-MerCreMer/loxP system. However, there is an ongoing debate on the occurrence of cardiac side effects caused by unspecific Cre activity or related to tamoxifen/oil overload. Here, we investigated potential adverse effects of DNA editing by the αMHC-MerCreMer/loxP system in combination with a low-dose treatment protocol with the tamoxifen metabolite 4-hydroxytamoxifen (OH-Txf). αMHC-MerCreMer mice received intraperitoneally OH-Txf (20 mg/kg) for 5 or 10 days. These treatment protocols were highly efficient to induce DNA editing in adult mouse hearts. Multi-parametric magnetic resonance imaging revealed neither transient nor permanent effects on cardiac function during or up to 19 days after 5 day OH-Txf treatment. Furthermore, OH-Txf did not affect cardiac phosphocreatine/ATP ratios assessed by in vivo 31P MR spectroscopy, indicating no Cre-mediated side effects on cardiac energy status. No MRI-based indication for the development of cardiac fibrosis was found as mean T1 relaxation time was unchanged. Histological analysis of myocardial collagen III content after OH-Txf confirmed this result. Last, mean T2 relaxation time was not altered after Txf treatment suggesting no pronounced cardiac lipid accumulation or tissue oedema. In additional experiments, cardiac function was assessed for up to 42 days to investigate potential delayed side effects of OH-Txf treatment. Neither 5- nor 10-day treatment resulted in a depression of cardiac function. Efficient cardiomyocyte-restricted DNA editing that is free of unwanted side effects on cardiac function, energetics or fibrosis can be achieved in adult mice when the αMHC-MerCreMer/loxP system is activated by the tamoxifen metabolite OH-Txf.
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Affiliation(s)
- Andre Heinen
- Institut für Herz- und Kreislaufphysiologie, Medizinische Fakultät und Universitätsklinikum Düsseldorf, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Stefanie Gödecke
- Institut für Herz- und Kreislaufphysiologie, Medizinische Fakultät und Universitätsklinikum Düsseldorf, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Ulrich Flögel
- Institut für Molekulare Kardiologie, Medizinische Fakultät und Universitätsklinikum Düsseldorf, Heinrich-Heine-Universität Düsseldorf, 40225, Düsseldorf, Germany
| | - Dominika Miklos
- Institut für Herz- und Kreislaufphysiologie, Medizinische Fakultät und Universitätsklinikum Düsseldorf, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Katharina Bottermann
- Institut für Herz- und Kreislaufphysiologie, Medizinische Fakultät und Universitätsklinikum Düsseldorf, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - André Spychala
- Institut für Herz- und Kreislaufphysiologie, Medizinische Fakultät und Universitätsklinikum Düsseldorf, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Axel Gödecke
- Institut für Herz- und Kreislaufphysiologie, Medizinische Fakultät und Universitätsklinikum Düsseldorf, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany.
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19
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Abstract
The Cre-LoxP technology permits gene ablation in specific cell lineages, at chosen differentiation stages of this lineage and in an inducible manner. It has allowed tremendous advances in our understanding of skeleton biology and related pathophysiological mechanisms, through the generation of loss/gain of function or cell tracing experiments based on the creation of an expanding toolbox of transgenic mice expressing the Cre recombinase in skeletal stem cells, chondrocytes, osteoblasts, or osteoclasts. In this chapter, we provide an overview of the different Cre-LoxP systems and Cre mouse lines used in the bone field, we discuss their advantages, limitations, and we outline best practices to interpret results obtained from the use of Cre mice.
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Affiliation(s)
- Florent Elefteriou
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
- Department of Orthopedic Surgery, Baylor College of Medicine, Houston, TX, USA.
| | - Greig Couasnay
- Department of Orthopedic Surgery, Baylor College of Medicine, Houston, TX, USA
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20
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Yoo S, Cha D, Kim S, Jiang L, Cooke P, Adebesin M, Wolfe A, Riddle R, Aja S, Blackshaw S. Tanycyte ablation in the arcuate nucleus and median eminence increases obesity susceptibility by increasing body fat content in male mice. Glia 2020; 68:1987-2000. [PMID: 32173924 PMCID: PMC7423758 DOI: 10.1002/glia.23817] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 02/28/2020] [Accepted: 02/28/2020] [Indexed: 12/11/2022]
Abstract
Tanycytes are radial glial cells located in the mediobasal hypothalamus. Recent studies have proposed that tanycytes play an important role in hypothalamic control of energy homeostasis, although this has not been directly tested. Here, we report the phenotype of mice in which tanycytes of the arcuate nucleus and median eminence were conditionally ablated in adult mice. Although the cerebrospinal fluid-hypothalamic barrier was rendered more permeable following tanycyte ablation, neither the blood-hypothalamic barrier nor leptin-induced pSTAT3 activation in hypothalamic parenchyma were affected. We observed a significant increase in visceral fat distribution accompanying insulin insensitivity in male mice, without significant effect on either body weight or food intake. A high-fat diet tended to accelerate overall body weight gain in tanycyte-ablated mice, but the development of visceral adiposity and insulin insensitivity was comparable to wildtype. Thermoneutral housing exacerbated fat accumulation and produced a shift away from fat oxidation in tanycyte-ablated mice. These results clarify the extent to which tanycytes regulate energy balance, and demonstrate a role for tanycytes in regulating fat metabolism.
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Affiliation(s)
- Sooyeon Yoo
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - David Cha
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Soohyun Kim
- Department of Orthopedic Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Lizhi Jiang
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Patrick Cooke
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Mobolanie Adebesin
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Andrew Wolfe
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Ryan Riddle
- Department of Orthopedic Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
- Baltimore Veterans Administration Medical Center, Baltimore, Maryland
| | - Susan Aja
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Seth Blackshaw
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland
- Center for Human Systems Biology, Johns Hopkins University School of Medicine, Baltimore, Maryland
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland
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21
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Altamura S, Vegi NM, Hoppe PS, Schroeder T, Aichler M, Walch A, Okreglicka K, Hültner L, Schneider M, Ladinig C, Kuklik-Roos C, Mysliwietz J, Janik D, Neff F, Rathkolb B, de Angelis MTH, Buske C, Silva ARD, Muedder K, Conrad M, Ganz T, Kopf M, Muckenthaler MU, Bornkamm GW. Glutathione peroxidase 4 and vitamin E control reticulocyte maturation, stress erythropoiesis and iron homeostasis. Haematologica 2019; 105:937-950. [PMID: 31248967 PMCID: PMC7109755 DOI: 10.3324/haematol.2018.212977] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Accepted: 06/20/2019] [Indexed: 12/27/2022] Open
Abstract
Glutathione peroxidase 4 (GPX4) is unique as it is the only enzyme that can prevent detrimental lipid peroxidation in vivo by reducing lipid peroxides to the respective alcohols thereby stabilizing oxidation products of unsaturated fatty acids. During reticulocyte maturation, lipid peroxidation mediated by 15-lipoxygenase in humans and rabbits and by 12/15-lipoxygenase (ALOX15) in mice was considered the initiating event for the elimination of mitochondria but is now known to occur through mitophagy. Yet, genetic ablation of the Alox15 gene in mice failed to provide evidence for this hypothesis. We designed a different genetic approach to tackle this open conundrum. Since either other lipoxygenases or non-enzymatic autooxidative mechanisms may compensate for the loss of Alox15, we asked whether ablation of Gpx4 in the hematopoietic system would result in the perturbation of reticulocyte maturation. Quantitative assessment of erythropoiesis indices in the blood, bone marrow (BM) and spleen of chimeric mice with Gpx4 ablated in hematopoietic cells revealed anemia with an increase in the fraction of erythroid precursor cells and reticulocytes. Additional dietary vitamin E depletion strongly aggravated the anemic phenotype. Despite strong extramedullary erythropoiesis reticulocytes failed to mature and accumulated large autophagosomes with engulfed mitochondria. Gpx4-deficiency in hematopoietic cells led to systemic hepatic iron overload and simultaneous severe iron demand in the erythroid system. Despite extremely high erythropoietin and erythroferrone levels in the plasma, hepcidin expression remained unchanged. Conclusively, perturbed reticulocyte maturation in response to Gpx4 loss in hematopoietic cells thus causes ineffective erythropoiesis, a phenotype partially masked by dietary vitamin E supplementation.
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Affiliation(s)
- Sandro Altamura
- Department of Pediatric Hematology, Oncology and Immunology - University of Heidelberg, Heidelberg, Germany.,Molecular Medicine Partnership Unit, Heidelberg, Germany
| | - Naidu M Vegi
- Institute of Experimental Cancer Research, Universitätsklinikum Ulm, Ulm, Germany
| | - Philipp S Hoppe
- Department of Biosystems Bioscience and Engineering, ETH Zürich, Basel, Switzerland
| | - Timm Schroeder
- Department of Biosystems Bioscience and Engineering, ETH Zürich, Basel, Switzerland
| | - Michaela Aichler
- Research Unit Analytical Pathology, Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Neuherberg, Germany
| | - Axel Walch
- Research Unit Analytical Pathology, Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Neuherberg, Germany
| | | | - Lothar Hültner
- Institute of Clinical Molecular Biology and Tumor Genetics, Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), München, Germany
| | - Manuela Schneider
- Institute for Stroke and Dementia Research (ISD), Klinikum der Universität München, München, Germany
| | - Camilla Ladinig
- Institute of Clinical Molecular Biology and Tumor Genetics, Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), München, Germany
| | - Cornelia Kuklik-Roos
- Institute of Clinical Molecular Biology and Tumor Genetics, Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), München, Germany
| | - Josef Mysliwietz
- Institute of Molecular Immunology, Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), München, Germany
| | - Dirk Janik
- Research Unit Analytical Pathology, Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Neuherberg, Germany
| | - Frauke Neff
- Research Unit Analytical Pathology, Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Neuherberg, Germany
| | - Birgit Rathkolb
- Institute of Molecular Animal Breeding and Biotechnology, Ludwig-Maximilians-Universität München, Genzentum, München, Germany.,Institute of Experimental Genetics, Geman Mouse Clinic (GMC), Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Neuherberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Mar Tin Hrabé de Angelis
- Institute of Experimental Genetics, Geman Mouse Clinic (GMC), Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Neuherberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany.,Chair of Experimental Genetics, School of Life Science Weihenstephan, Technische Universität München, Freising, Germany
| | - Christian Buske
- Institute of Experimental Cancer Research, Universitätsklinikum Ulm, Ulm, Germany
| | - Ana Rita da Silva
- Department of Pediatric Hematology, Oncology and Immunology - University of Heidelberg, Heidelberg, Germany.,Molecular Medicine Partnership Unit, Heidelberg, Germany
| | - Katja Muedder
- Department of Pediatric Hematology, Oncology and Immunology - University of Heidelberg, Heidelberg, Germany.,Molecular Medicine Partnership Unit, Heidelberg, Germany
| | - Marcus Conrad
- Institute of Developmental Genetics, Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Neuherberg, Germany
| | - Tomas Ganz
- Departments of Medicine and Pathology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Manfred Kopf
- Institute of Molecular Health Sciences, ETH Zurich, Zürich, Switzerland
| | - Martina U Muckenthaler
- Department of Pediatric Hematology, Oncology and Immunology - University of Heidelberg, Heidelberg, Germany.,Molecular Medicine Partnership Unit, Heidelberg, Germany
| | - Georg W Bornkamm
- Institute of Clinical Molecular Biology and Tumor Genetics, Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), München, Germany
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22
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Ceasrine AM, Ruiz-Otero N, Lin EE, Lumelsky DN, Boehm ED, Kuruvilla R. Tamoxifen Improves Glucose Tolerance in a Delivery-, Sex-, and Strain-Dependent Manner in Mice. Endocrinology 2019; 160:782-790. [PMID: 30759201 PMCID: PMC6424092 DOI: 10.1210/en.2018-00985] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 02/07/2019] [Indexed: 12/19/2022]
Abstract
Tamoxifen, a selective estrogen-receptor modulator, is widely used in mouse models to temporally control gene expression but is also known to affect body composition. We report that tamoxifen has significant and sustained effects on glucose tolerance, independent of effects on insulin sensitivity, in mice. IP, but not oral, tamoxifen delivery improved glucose tolerance in three inbred mouse strains. The extent and persistence of tamoxifen-induced effects were sex and strain dependent. These findings highlight the need to revise commonly used tamoxifen-based protocols for gene manipulation in mice by including longer chase periods after injection, oral delivery, and the use of tamoxifen-treated littermate controls.
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Affiliation(s)
- Alexis M Ceasrine
- Department of Biology, Johns Hopkins University, Baltimore, Maryland
- Correspondence: Alexis M. Ceasrine, PhD, Johns Hopkins University, 3400 N. Charles Street, Mudd Hall 200, Baltimore, Maryland 21218. E-mail:
| | | | - Eugene E Lin
- Department of Biology, Johns Hopkins University, Baltimore, Maryland
| | - David N Lumelsky
- Department of Biology, Johns Hopkins University, Baltimore, Maryland
| | - Erica D Boehm
- Department of Biology, Johns Hopkins University, Baltimore, Maryland
| | - Rejji Kuruvilla
- Department of Biology, Johns Hopkins University, Baltimore, Maryland
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23
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Maani N, Sabha N, Rezai K, Ramani A, Groom L, Eltayeb N, Mavandadnejad F, Pang A, Russo G, Brudno M, Haucke V, Dirksen RT, Dowling JJ. Tamoxifen therapy in a murine model of myotubular myopathy. Nat Commun 2018; 9:4849. [PMID: 30451841 PMCID: PMC6242823 DOI: 10.1038/s41467-018-07057-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 10/12/2018] [Indexed: 02/07/2023] Open
Abstract
Myotubular myopathy (MTM) is a severe X-linked disease without existing therapies. Here, we show that tamoxifen ameliorates MTM-related histopathological and functional abnormalities in mice, and nearly doubles survival. The beneficial effects of tamoxifen are mediated primarily via estrogen receptor signaling, as demonstrated through in vitro studies and in vivo phenotypic rescue with estradiol. RNA sequencing and protein expression analyses revealed that rescue is mediated in part through post-transcriptional reduction of dynamin-2, a known MTM modifier. These findings demonstrate an unexpected ability of tamoxifen to improve the murine MTM phenotype, providing preclinical evidence to support clinical translation.
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MESH Headings
- Animals
- Disease Models, Animal
- Drug Evaluation, Preclinical
- Dynamin II/genetics
- Dynamin II/metabolism
- Estradiol/metabolism
- Estradiol/pharmacology
- Excitation Contraction Coupling/drug effects
- Female
- Gene Expression/drug effects
- High-Throughput Nucleotide Sequencing
- Humans
- Longevity/drug effects
- Male
- Mice
- Mice, Knockout
- Motor Activity/drug effects
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/pathology
- Myofibrils/drug effects
- Myofibrils/metabolism
- Myofibrils/ultrastructure
- Myopathies, Structural, Congenital/drug therapy
- Myopathies, Structural, Congenital/genetics
- Myopathies, Structural, Congenital/metabolism
- Myopathies, Structural, Congenital/pathology
- Protective Agents/pharmacology
- Protein Tyrosine Phosphatases, Non-Receptor/deficiency
- Protein Tyrosine Phosphatases, Non-Receptor/genetics
- Receptors, Estrogen/genetics
- Receptors, Estrogen/metabolism
- Tamoxifen/pharmacology
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Affiliation(s)
- Nika Maani
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON, CAN M5G 0A4, Canada
- Department of Molecular Genetics, University of Toronto, Medical Science Building, Room 4386, 1 King's College Cir, Toronto, ON, CAN M5S 1A8, Canada
| | - Nesrin Sabha
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON, CAN M5G 0A4, Canada
- Department of Molecular Genetics, University of Toronto, Medical Science Building, Room 4386, 1 King's College Cir, Toronto, ON, CAN M5S 1A8, Canada
- Department of Paediatrics, University of Toronto, Room 1436D, 555 University Avenue, Toronto, ON, CAN M5G 1X8, Canada
| | - Kamran Rezai
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON, CAN M5G 0A4, Canada
- Department of Molecular Genetics, University of Toronto, Medical Science Building, Room 4386, 1 King's College Cir, Toronto, ON, CAN M5S 1A8, Canada
| | - Arun Ramani
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON, CAN M5G 0A4, Canada
- Department of Computer Science, University of Toronto, Pratt Building Room 286C, 6 King's College Rd, Toronto, ON, CAN M5S 3G4, Canada
- Centre for Computational Medicine, The Hospital for Sick Children, 686 Bay Street, Toronto, ON, CAN M5G 0A4, Canada
| | - Linda Groom
- Department of Pharmacology and Physiology, University of Rochester Medical Center School of Medicine and Dentistry, 601 Elmwood Ave, Box 711, Rochester, NY, 14642, USA
| | - Nadine Eltayeb
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON, CAN M5G 0A4, Canada
| | - Faranak Mavandadnejad
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON, CAN M5G 0A4, Canada
| | - Andrea Pang
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON, CAN M5G 0A4, Canada
| | - Giulia Russo
- Department of Molecular Pharmacology and Cell Biology, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany
| | - Michael Brudno
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON, CAN M5G 0A4, Canada
- Department of Computer Science, University of Toronto, Pratt Building Room 286C, 6 King's College Rd, Toronto, ON, CAN M5S 3G4, Canada
- Centre for Computational Medicine, The Hospital for Sick Children, 686 Bay Street, Toronto, ON, CAN M5G 0A4, Canada
| | - Volker Haucke
- Department of Molecular Pharmacology and Cell Biology, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany
| | - Robert T Dirksen
- Department of Pharmacology and Physiology, University of Rochester Medical Center School of Medicine and Dentistry, 601 Elmwood Ave, Box 711, Rochester, NY, 14642, USA
| | - James J Dowling
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON, CAN M5G 0A4, Canada.
- Department of Molecular Genetics, University of Toronto, Medical Science Building, Room 4386, 1 King's College Cir, Toronto, ON, CAN M5S 1A8, Canada.
- Department of Paediatrics, University of Toronto, Room 1436D, 555 University Avenue, Toronto, ON, CAN M5G 1X8, Canada.
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24
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Tatsumi K, Isonishi A, Yamasaki M, Kawabe Y, Morita-Takemura S, Nakahara K, Terada Y, Shinjo T, Okuda H, Tanaka T, Wanaka A. Olig2-Lineage Astrocytes: A Distinct Subtype of Astrocytes That Differs from GFAP Astrocytes. Front Neuroanat 2018; 12:8. [PMID: 29497365 PMCID: PMC5819569 DOI: 10.3389/fnana.2018.00008] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 01/19/2018] [Indexed: 12/22/2022] Open
Abstract
Astrocytes are the most abundant glia cell type in the central nervous system (CNS), and are known to constitute heterogeneous populations that differ in their morphology, gene expression and function. Although glial fibrillary acidic protein (GFAP) is the cardinal cytological marker of CNS astrocytes, GFAP-negative astrocytes can easily be found in the adult CNS. Astrocytes are also allocated to spatially distinct regional domains during development. This regional heterogeneity suggests that they help to coordinate post-natal neural circuit formation and thereby to regulate eventual neuronal activity. Here, during lineage-tracing studies of cells expressing Olig2 using Olig2CreER; Rosa-CAG-LSL-eNpHR3.0-EYFP transgenic mice, we found Olig2-lineage mature astrocytes in the adult forebrain. Long-term administration of tamoxifen resulted in sufficient recombinant induction, and Olig2-lineage cells were found to be preferentially clustered in some adult brain nuclei. We then made distribution map of Olig2-lineage astrocytes in the adult mouse brain, and further compared the map with the distribution of GFAP-positive astrocytes visualized in GFAPCre; Rosa-CAG-LSL-eNpHR3.0-EYFP mice. Brain regions rich in Olig2-lineage astrocytes (e.g., basal forebrain, thalamic nuclei, and deep cerebellar nuclei) tended to lack GFAP-positive astrocytes, and vice versa. Even within a single brain nucleus, Olig2-lineage astrocytes and GFAP astrocytes frequently occupied mutually exclusive territories. These findings strongly suggest that there is a subpopulation of astrocytes (Olig2-lineage astrocytes) in the adult brain, and that it differs from GFAP-positive astrocytes in its distribution pattern and perhaps also in its function. Interestingly, the brain nuclei rich in Olig2-lineage astrocytes strongly expressed GABA-transporter 3 in astrocytes and vesicular GABA transporter in neurons, suggesting that Olig2-lineage astrocytes are involved in inhibitory neuronal transmission.
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Affiliation(s)
- Kouko Tatsumi
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Japan
| | - Ayami Isonishi
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Japan
| | - Miwako Yamasaki
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Yoshie Kawabe
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Japan
| | - Shoko Morita-Takemura
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Japan
| | - Kazuki Nakahara
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Japan
| | - Yuki Terada
- Department of Anesthesiology, Faculty of Medicine, Nara Medical University, Kashihara, Japan
| | - Takeaki Shinjo
- Department of Anesthesiology, Faculty of Medicine, Nara Medical University, Kashihara, Japan
| | - Hiroaki Okuda
- Department of Functional Anatomy, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan
| | - Tatsuhide Tanaka
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Japan
| | - Akio Wanaka
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Japan
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25
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Saenz JB, Burclaff J, Mills JC. Modeling Murine Gastric Metaplasia Through Tamoxifen-Induced Acute Parietal Cell Loss. Methods Mol Biol 2017; 1422:329-39. [PMID: 27246044 DOI: 10.1007/978-1-4939-3603-8_28] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Parietal cell loss represents the initial step in the sequential progression toward gastric adenocarcinoma. In the setting of chronic inflammation, the expansion of the mucosal response to parietal cell loss characterizes a crucial transition en route to gastric dysplasia. Here, we detail methods for using the selective estrogen receptor modulator tamoxifen as a novel tool to rapidly and reversibly induce parietal cell loss in mice in order to study the mechanisms that underlie these pre-neoplastic events.
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Affiliation(s)
- Jose B Saenz
- Division of Gastroenterology, Departments of Medicine, Washington University School of Medicine, Box 8124, 660 So. Euclid Ave., St. Louis, MO, 63110, USA
| | - Joseph Burclaff
- Division of Gastroenterology, Departments of Medicine, Washington University School of Medicine, Box 8124, 660 So. Euclid Ave., St. Louis, MO, 63110, USA.,Division of Gastroenterology, Departments of Developmental Biology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Jason C Mills
- Division of Gastroenterology, Departments of Medicine, Washington University School of Medicine, Box 8124, 660 So. Euclid Ave., St. Louis, MO, 63110, USA. .,Division of Gastroenterology, Departments of Developmental Biology, Washington University School of Medicine, St. Louis, MO, 63110, USA. .,Division of Gastroenterology, Departments of Pathology & Immunology, Washington University School of Medicine, St. Louis, MO, 63110, USA.
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26
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Varol D, Mildner A, Blank T, Shemer A, Barashi N, Yona S, David E, Boura-Halfon S, Segal-Hayoun Y, Chappell-Maor L, Keren-Shaul H, Leshkowitz D, Hornstein E, Fuhrmann M, Amit I, Maggio N, Prinz M, Jung S. Dicer Deficiency Differentially Impacts Microglia of the Developing and Adult Brain. Immunity 2017. [DOI: 10.1016/j.immuni.2017.05.003] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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27
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Kiermayer C, Northrup E, Schrewe A, Walch A, de Angelis MH, Schoensiegel F, Zischka H, Prehn C, Adamski J, Bekeredjian R, Ivandic B, Kupatt C, Brielmeier M. Heart-Specific Knockout of the Mitochondrial Thioredoxin Reductase (Txnrd2) Induces Metabolic and Contractile Dysfunction in the Aging Myocardium. J Am Heart Assoc 2015; 4:e002153. [PMID: 26199228 PMCID: PMC4608093 DOI: 10.1161/jaha.115.002153] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 05/19/2015] [Indexed: 01/19/2023]
Abstract
BACKGROUND Ubiquitous deletion of thioredoxin reductase 2 (Txnrd2) in mice is embryonically lethal and associated with abnormal heart development, while constitutive, heart-specific Txnrd2 inactivation leads to dilated cardiomyopathy and perinatal death. The significance of Txnrd2 in aging cardiomyocytes, however, has not yet been examined. METHODS AND RESULTS The tamoxifen-inducible heart-specific αMHC-MerCreMer transgene was used to inactivate loxP-flanked Txnrd2 alleles in adult mice. Hearts and isolated mitochondria from aged knockout mice were morphologically and functionally analyzed. Echocardiography revealed a significant increase in left ventricular end-systolic diameters in knockouts. Fractional shortening and ejection fraction were decreased compared with controls. Ultrastructural analysis of cardiomyocytes of aged mice showed mitochondrial degeneration and accumulation of autophagic bodies. A dysregulated autophagic activity was supported by higher levels of lysosome-associated membrane protein 1 (LAMP1), microtubule-associated protein 1A/1B-light chain 3-I (LC3-I), and p62 in knockout hearts. Isolated Txnrd2-deficient mitochondria used less oxygen and tended to produce more reactive oxygen species. Chronic hypoxia inducible factor 1, α subunit stabilization and altered transcriptional and metabolic signatures indicated that energy metabolism is deregulated. CONCLUSIONS These results imply a novel role of Txnrd2 in sustaining heart function during aging and suggest that Txnrd2 may be a modifier of heart failure.
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MESH Headings
- Age Factors
- Animals
- Autophagy
- Blood Pressure
- Disease Models, Animal
- Energy Metabolism
- Gene Expression Profiling/methods
- Gene Expression Regulation
- Genetic Predisposition to Disease
- Heart Failure/enzymology
- Heart Failure/genetics
- Heart Failure/pathology
- Heart Failure/physiopathology
- Hypoxia-Inducible Factor 1, alpha Subunit/genetics
- Hypoxia-Inducible Factor 1, alpha Subunit/metabolism
- Lysosomal Membrane Proteins/genetics
- Lysosomal Membrane Proteins/metabolism
- Metabolomics/methods
- Mice, Knockout
- Microtubule-Associated Proteins/genetics
- Microtubule-Associated Proteins/metabolism
- Mitochondria, Heart/enzymology
- Mitochondria, Heart/ultrastructure
- Myocardial Contraction
- Myocytes, Cardiac/enzymology
- Myocytes, Cardiac/ultrastructure
- Oxidative Stress
- Phenotype
- RNA, Messenger/metabolism
- Reactive Oxygen Species/metabolism
- Stroke Volume
- Thioredoxin Reductase 2/deficiency
- Thioredoxin Reductase 2/genetics
- Time Factors
- Ventricular Dysfunction, Left/enzymology
- Ventricular Dysfunction, Left/genetics
- Ventricular Dysfunction, Left/physiopathology
- Ventricular Function, Left
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Affiliation(s)
- Claudia Kiermayer
- Research Unit Comparative Medicine, Helmholtz Zentrum München, German Research Center for Environmental HealthNeuherberg, Germany
| | - Emily Northrup
- Research Unit Comparative Medicine, Helmholtz Zentrum München, German Research Center for Environmental HealthNeuherberg, Germany
| | - Anja Schrewe
- Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental HealthNeuherberg, Germany
| | - Axel Walch
- Reserach Unit Analytical Pathology, Helmholtz Zentrum München, German Research Center for Environmental HealthNeuherberg, Germany
| | - Martin Hrabe de Angelis
- Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental HealthNeuherberg, Germany
- Chair of Experimental Genetics, Technische Universität MünchenMunich, Germany
| | - Frank Schoensiegel
- Department of Internal Medicine III, University of HeidelbergHeidelberg, Germany
| | - Hans Zischka
- Institute of molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental HealthNeuherberg, Germany
| | - Cornelia Prehn
- Institute of Experimental Genetics, Genome Analysis Center, Helmholtz Zentrum München, German Research Center for Environmental HealthNeuherberg, Germany
| | - Jerzy Adamski
- Institute of Experimental Genetics, Genome Analysis Center, Helmholtz Zentrum München, German Research Center for Environmental HealthNeuherberg, Germany
- Chair of Experimental Genetics, Technische Universität MünchenMunich, Germany
| | - Raffi Bekeredjian
- Department of Internal Medicine III, University of HeidelbergHeidelberg, Germany
| | - Boris Ivandic
- Department of Internal Medicine III, University of HeidelbergHeidelberg, Germany
| | - Christian Kupatt
- I. Medizinische Klinik und Poliklinik, Klinikum Rechts der Isar, TU MunichMunich, Germany
- German Center for Cardiovascular Research (DZHK) partner site Munich Heart AllianceMunich, Germany
| | - Markus Brielmeier
- Research Unit Comparative Medicine, Helmholtz Zentrum München, German Research Center for Environmental HealthNeuherberg, Germany
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28
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Abstract
The strategy of fusing a protein of interest to a hormone-binding domain (HBD) of a steroid hormone receptor allows fine control of the activity of the fused protein. Such fusion proteins are inactive in the absence of ligand, because they are complexed with a variety of intracellular polypeptides. Upon ligand binding, the receptor is released from its inhibitory complex and the fusion protein becomes functional. In the murine estrogen receptor (ER) fusion system, proteins are fused to the HBD of the ER. The system relies on the use of a mutant ER known as ER(TAM). Compared to the wild-type HBD, ER(TAM) has 1000-fold lower affinity for estrogen, yet remains responsive to activation by the synthetic steroid 4-hydroxytamoxifen (4-OHT). Because 4-OHT is expensive, animals can be treated with the cheaper precursor tamoxifen, which is converted into 4-OHT by a liver enzyme. Here we present an overview of the methods used to deliver tamoxifen to mice. The most used method is intraperitoneal injection, because the amount of administered compound can be better controlled, but delivery by oral gavage is also possible. For short-term and immediate-effect studies or when conversion of tamoxifen by the liver is to be avoided, 4-OHT can be used directly.
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Affiliation(s)
- Jonathan Whitfield
- Vall d'Hebron Institute of Oncology (VHIO), Barcelona 08035, Spain; Universitat Autònoma de Barcelona, 08193 Bellaterra (Cerdanyola del Vallès), Spain
| | - Trevor Littlewood
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, United Kingdom
| | - Laura Soucek
- Vall d'Hebron Institute of Oncology (VHIO), Barcelona 08035, Spain; Universitat Autònoma de Barcelona, 08193 Bellaterra (Cerdanyola del Vallès), Spain
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29
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Taniguchi CM, Miao YR, Diep AN, Wu C, Rankin EB, Atwood TF, Xing L, Giaccia AJ. PHD inhibition mitigates and protects against radiation-induced gastrointestinal toxicity via HIF2. Sci Transl Med 2014; 6:236ra64. [PMID: 24828078 DOI: 10.1126/scitranslmed.3008523] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Radiation-induced gastrointestinal (GI) toxicity can be a major source of morbidity and mortality after radiation exposure. There is an unmet need for effective preventative or mitigative treatments against the potentially fatal diarrhea and water loss induced by radiation damage to the GI tract. We report that prolyl hydroxylase inhibition by genetic knockout or pharmacologic inhibition of all PHD (prolyl hydroxylase domain) isoforms by the small-molecule dimethyloxallyl glycine (DMOG) increases hypoxia-inducible factor (HIF) expression, improves epithelial integrity, reduces apoptosis, and increases intestinal angiogenesis, all of which are essential for radioprotection. HIF2, but not HIF1, is both necessary and sufficient to prevent radiation-induced GI toxicity and death. Increased vascular endothelial growth factor (VEGF) expression contributes to the protective effects of HIF2, because inhibition of VEGF function reversed the radioprotection and radiomitigation afforded by DMOG. Additionally, mortality from abdominal or total body irradiation was reduced even when DMOG was given 24 hours after exposure. Thus, prolyl hydroxylase inhibition represents a treatment strategy to protect against and mitigate GI toxicity from both therapeutic radiation and potentially lethal radiation exposures.
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Affiliation(s)
- Cullen M Taniguchi
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA
| | - Yu Rebecca Miao
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA
| | - Anh N Diep
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA
| | - Colleen Wu
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA
| | - Erinn B Rankin
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA
| | - Todd F Atwood
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA
| | - Lei Xing
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA
| | - Amato J Giaccia
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA.
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30
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Inactivation of the ferroptosis regulator Gpx4 triggers acute renal failure in mice. Nat Cell Biol 2014; 16:1180-91. [PMID: 25402683 DOI: 10.1038/ncb3064] [Citation(s) in RCA: 2081] [Impact Index Per Article: 208.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 10/14/2014] [Indexed: 02/06/2023]
Abstract
Ferroptosis is a non-apoptotic form of cell death induced by small molecules in specific tumour types, and in engineered cells overexpressing oncogenic RAS. Yet, its relevance in non-transformed cells and tissues is unexplored and remains enigmatic. Here, we provide direct genetic evidence that the knockout of glutathione peroxidase 4 (Gpx4) causes cell death in a pathologically relevant form of ferroptosis. Using inducible Gpx4(-/-) mice, we elucidate an essential role for the glutathione/Gpx4 axis in preventing lipid-oxidation-induced acute renal failure and associated death. We furthermore systematically evaluated a library of small molecules for possible ferroptosis inhibitors, leading to the discovery of a potent spiroquinoxalinamine derivative called Liproxstatin-1, which is able to suppress ferroptosis in cells, in Gpx4(-/-) mice, and in a pre-clinical model of ischaemia/reperfusion-induced hepatic damage. In sum, we demonstrate that ferroptosis is a pervasive and dynamic form of cell death, which, when impeded, promises substantial cytoprotection.
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31
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Miura H, Scott JK, Harada S, Barlow LA. Sonic hedgehog-expressing basal cells are general post-mitotic precursors of functional taste receptor cells. Dev Dyn 2014; 243:1286-97. [PMID: 24590958 DOI: 10.1002/dvdy.24121] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 02/13/2014] [Accepted: 02/13/2014] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Taste buds contain ∼60 elongate cells and several basal cells. Elongate cells comprise three functional taste cell types: I, glial cells; II, bitter/sweet/umami receptor cells; and III, sour detectors. Although taste cells are continuously renewed, lineage relationships among cell types are ill-defined. Basal cells have been proposed as taste bud stem cells, a subset of which express Sonic hedgehog (Shh). However, Shh+ basal cells turn over rapidly suggesting that Shh+ cells are post-mitotic precursors of some or all taste cell types. RESULTS To fate map Shh-expressing cells, mice carrying ShhCreER(T2) and a high (CAG-CAT-EGFP) or low (R26RLacZ) efficiency reporter allele were given tamoxifen to activate Cre in Shh+ cells. Using R26RLacZ, lineage-labeled cells occur singly within buds, supporting a post-mitotic state for Shh+ cells. Using either reporter, we show that Shh+ cells differentiate into all three taste cell types, in proportions reflecting cell type ratios in taste buds (I > II > III). CONCLUSIONS Shh+ cells are not stem cells, but are post-mitotic, immediate precursors of taste cells. Shh+ cells differentiate into each of the three taste cell types, and the choice of a specific taste cell fate is regulated to maintain the proper ratio within buds.
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Affiliation(s)
- Hirohito Miura
- Department of Oral Physiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Kagoshima, Japan
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32
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McClain J, Grubišić V, Fried D, Gomez-Suarez RA, Leinninger GM, Sévigny J, Parpura V, Gulbransen BD. Ca2+ responses in enteric glia are mediated by connexin-43 hemichannels and modulate colonic transit in mice. Gastroenterology 2014; 146:497-507.e1. [PMID: 24211490 PMCID: PMC3935238 DOI: 10.1053/j.gastro.2013.10.061] [Citation(s) in RCA: 148] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 10/18/2013] [Accepted: 10/30/2013] [Indexed: 12/17/2022]
Abstract
BACKGROUND & AIMS In the enteric nervous system, neurotransmitters initiate changes in calcium (Ca(2+) responses) in glia, but it is not clear how this process affects intestinal function. We investigated whether Ca(2+)-mediated responses in enteric glia are required to maintain gastrointestinal function. METHODS We used in situ Ca(2+) imaging to monitor glial Ca(2+) responses, which were manipulated with pharmacologic agents or via glia-specific disruption of the gene encoding connexin-43 (Cx43) (hGFAP::CreER(T2+/-)/Cx43(f/f) mice). Gastrointestinal function was assessed based on pellet output, total gut transit, colonic bead expulsion, and muscle tension recordings. Proteins were localized and quantified by immunohistochemistry, immunoblot, and reverse transcription polymerase chain reaction analyses. RESULTS Ca(2+) responses in enteric glia of mice were mediated by Cx43 hemichannels. Cx43 immunoreactivity was confined to enteric glia within the myenteric plexus of the mouse colon; the Cx43 inhibitors carbenoxolone and 43Gap26 inhibited the ability of enteric glia to propagate Ca(2+) responses. In vivo attenuation of Ca(2+) responses in the enteric glial network slowed gut transit overall and delayed colonic transit--these changes are also observed during normal aging. Altered motility with increasing age was associated with reduced glial Ca(2+)-mediated responses and changes in glial expression of Cx43 messenger RNA and protein. CONCLUSIONS Ca(2+)-mediated responses in enteric glia regulate gastrointestinal function in mice. Altered intercellular signaling between enteric glia and neurons might contribute to motility disorders.
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Affiliation(s)
- Jonathon McClain
- Neuroscience Program and Department of Physiology, Michigan State University, 567 Wilson Road, East Lansing, MI, 48824 USA
| | - Vladimir Grubišić
- Department of Neurobiology, Center for Glial Biology in Medicine, Atomic Force Microscopy and Nanotechnology Laboratories, Civitan International Research Center, Evelyn F. McKnight Brain Institute, University of Alabama, Birmingham, AL 35294, USA
| | - David Fried
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824
| | - Roberto A Gomez-Suarez
- Department of Neurobiology, Center for Glial Biology in Medicine, Atomic Force Microscopy and Nanotechnology Laboratories, Civitan International Research Center, Evelyn F. McKnight Brain Institute, University of Alabama, Birmingham, AL 35294, USA.,Department of Pediatrics Division of Pediatric Gastroenterology Hepatology And Nutrition at Nemours Chlidren's Hospital. Orlando, FL 32827, USA
| | - Gina M Leinninger
- Neuroscience Program and Department of Physiology, Michigan State University, 567 Wilson Road, East Lansing, MI, 48824 USA
| | - Jean Sévigny
- Département de microbiologie-infectiologie et d'immunologie, Faculté de Médecine, Université Laval, Québec, QC, Canada.,Centre de recherche du CHU de Québec, Québec, QC, G1V 4G2 Canada
| | - Vladimir Parpura
- Department of Neurobiology, Center for Glial Biology in Medicine, Atomic Force Microscopy and Nanotechnology Laboratories, Civitan International Research Center, Evelyn F. McKnight Brain Institute, University of Alabama, Birmingham, AL 35294, USA.,Department of Biotechnology, University of Rijeka, 51000 Rijeka, Croatia
| | - Brian D Gulbransen
- Neuroscience Program and Department of Physiology, Michigan State University, 567 Wilson Road, East Lansing, MI, 48824 USA
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33
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Heinze C, Seniuk A, Sokolov MV, Huebner AK, Klementowicz AE, Szijártó IA, Schleifenbaum J, Vitzthum H, Gollasch M, Ehmke H, Schroeder BC, Hübner CA. Disruption of vascular Ca2+-activated chloride currents lowers blood pressure. J Clin Invest 2014; 124:675-86. [PMID: 24401273 DOI: 10.1172/jci70025] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 10/24/2013] [Indexed: 01/23/2023] Open
Abstract
High blood pressure is the leading risk factor for death worldwide. One of the hallmarks is a rise of peripheral vascular resistance, which largely depends on arteriole tone. Ca2+-activated chloride currents (CaCCs) in vascular smooth muscle cells (VSMCs) are candidates for increasing vascular contractility. We analyzed the vascular tree and identified substantial CaCCs in VSMCs of the aorta and carotid arteries. CaCCs were small or absent in VSMCs of medium-sized vessels such as mesenteric arteries and larger retinal arterioles. In small vessels of the retina, brain, and skeletal muscle, where contractile intermediate cells or pericytes gradually replace VSMCs, CaCCs were particularly large. Targeted disruption of the calcium-activated chloride channel TMEM16A, also known as ANO1, in VSMCs, intermediate cells, and pericytes eliminated CaCCs in all vessels studied. Mice lacking vascular TMEM16A had lower systemic blood pressure and a decreased hypertensive response following vasoconstrictor treatment. There was no difference in contractility of medium-sized mesenteric arteries; however, responsiveness of the aorta and small retinal arterioles to the vasoconstriction-inducing drug U46619 was reduced. TMEM16A also was required for peripheral blood vessel contractility, as the response to U46619 was attenuated in isolated perfused hind limbs from mutant mice. Out data suggest that TMEM16A plays a general role in arteriolar and capillary blood flow and is a promising target for the treatment of hypertension.
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34
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Sledzińska A, Fairbairn L, Buch T. Manipulation of T cell function and conditional gene targeting in T cells. Methods Mol Biol 2014; 1193:153-169. [PMID: 25151005 DOI: 10.1007/978-1-4939-1212-4_15] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Cre-Lox recombination is known as a site-specific recombinase technology, and is widely used to carry out modification at specific sites in the DNA of cells. The system consists of an enzyme, Cre recombinase, that recombines a pair of short target sequences, the lox sites. The Cre-Lox system can be used to activate or repress a gene depending on the placement of the lox sites. Placing the Cre recombinase under the control of a cell-specific promoter allows expression only in specific cells or cellular subsets, thus providing a powerful tool for analysis of gene function at specific developmental or physiological niches. Nowadays almost every aspect of T cell biology can be approached by a specific Cre model. This powerful tool allows scientists to overcome the limitations of gene-deficient animals and target a gene of interest specifically in T cell or T cell subsets by appropriate placement of the lox sites. Here we describe the main Cre lines that enable gene targeting in T helper cells or CD4 T cell subsets, and the most common methods of assessing the recombination efficiency.
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Affiliation(s)
- Anna Sledzińska
- Institute of Experimental Immunology, University of Zürich, Zürich, Switzerland
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35
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Regulation of diet-induced adipose tissue and systemic inflammation by salicylates and pioglitazone. PLoS One 2013; 8:e82847. [PMID: 24376593 PMCID: PMC3871540 DOI: 10.1371/journal.pone.0082847] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 10/29/2013] [Indexed: 11/19/2022] Open
Abstract
It is increasingly accepted that chronic inflammation participates in obesity-induced insulin resistance and type 2 diabetes (T2D). Salicylates and thiazolidinediones (TZDs) both have anti-inflammatory and anti-hyperglycemic properties. The present study compared the effects of these drugs on obesity-induced inflammation in adipose tissue (AT) and AT macrophages (ATMs), as well as the metabolic and immunological phenotypes of the animal models. Both drugs improved high fat diet (HFD)-induced insulin resistance. However, salicylates did not affect AT and ATM inflammation, whereas Pioglitazone improved these parameters. Interestingly, HFD and the drug treatments all modulated systemic inflammation as assessed by changes in circulating immune cell numbers and activation states. HFD increased the numbers of circulating white blood cells, neutrophils, and a pro-inflammatory monocyte subpopulation (Ly6Chi), whereas salicylates and Pioglitazone normalized these cell numbers. The drug treatments also decreased circulating lymphocyte numbers. These data suggest that obesity induces systemic inflammation by regulating circulating immune cell phenotypes and that anti-diabetic interventions suppress systemic inflammation by normalizing circulating immune phenotypes.
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36
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Owen C, Lees EK, Grant L, Zimmer DJ, Mody N, Bence KK, Delibegović M. Inducible liver-specific knockdown of protein tyrosine phosphatase 1B improves glucose and lipid homeostasis in adult mice. Diabetologia 2013; 56:2286-96. [PMID: 23832083 DOI: 10.1007/s00125-013-2992-z] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Accepted: 06/14/2013] [Indexed: 12/19/2022]
Abstract
AIMS/HYPOTHESIS Protein tyrosine phosphatase 1B (PTP1B) is a key negative regulator of insulin signalling. Hepatic PTP1B deficiency, using the Alb-Cre promoter to drive Ptp1b deletion from birth in mice, improves glucose homeostasis, insulin sensitivity and lipid metabolism. The aim of this study was to investigate the therapeutic potential of decreasing liver PTP1B levels in obese and insulin-resistant adult mice. METHODS Inducible Ptp1b liver-specific knockout mice were generated using SA-Cre-ER(T2) mice crossed with Ptp1b floxed (Ptp1b(fl/fl)) mice. Mice were fed a high-fat diet (HFD) for 12 weeks to induce obesity and insulin resistance. Tamoxifen was administered in the HFD to induce liver-specific deletion of Ptp1b (SA-Ptp1b(-/-) mice). Body weight, glucose homeostasis, lipid homeostasis, serum adipokines, insulin signalling and endoplasmic reticulum (ER) stress were examined. RESULTS Despite no significant change in body weight relative to HFD-fed Ptp1b(fl/fl) control mice, HFD-fed SA-Ptp1b(-/-) mice exhibited a reversal of glucose intolerance as determined by improved glucose and pyruvate tolerance tests, decreased fed and fasting blood glucose and insulin levels, lower HOMA of insulin resistance, circulating leptin, serum and liver triacylglycerols, serum NEFA and decreased HFD-induced ER stress. This was associated with decreased glycogen synthase, eukaryotic translation initiation factor-2α kinase 3, eukaryotic initiation factor 2α and c-Jun NH2-terminal kinase 2 phosphorylation, and decreased expression of Pepck. CONCLUSIONS/INTERPRETATION Inducible liver-specific PTP1B knockdown reverses glucose intolerance and improves lipid homeostasis in HFD-fed obese and insulin-resistant adult mice. This suggests that knockdown of liver PTP1B in individuals who are already obese/insulin resistant may have relatively rapid, beneficial therapeutic effects.
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Affiliation(s)
- C Owen
- Institute of Medical Sciences, School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
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37
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Lexow J, Poggioli T, Sarathchandra P, Santini MP, Rosenthal N. Cardiac fibrosis in mice expressing an inducible myocardial-specific Cre driver. Dis Model Mech 2013; 6:1470-6. [PMID: 23929940 PMCID: PMC3820269 DOI: 10.1242/dmm.010470] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Tamoxifen-inducible Cre-mediated manipulation of animal genomes has achieved wide acceptance over the last decade, with numerous important studies heavily relying on this technique. Recently, a number of groups have reported transient complications of using this protocol in the heart. In the present study we observed a previously unreported focal fibrosis and depressed left-ventricular function in tamoxifen-treated αMHC-MerCreMer-positive animals in a Tβ4shRNAflox × αMHC-MerCreMer cross at 6-7 weeks following standard tamoxifen treatment, regardless of the presence of the floxed transgene. The phenotype was reproduced by treating mice from the original αMHC-MerCreMer strain with tamoxifen. In the acute phase after tamoxifen treatment, cell infiltration into the myocardium was accompanied by increased expression of pro-inflammatory cytokines (IL-1β, IL-6, TNFα, IFNγ, Ccl2) and markers of hypertrophy (ANF, BNP, Col3a1). These observations highlight the requirement for including tamoxifen-treated MerCreMer littermate controls to avert misinterpretation of conditional mutant phenotypes. A survey of the field as well as the protocols presented here suggests that controlling the parameters of tamoxifen delivery is important in avoiding the chronic MerCreMer-mediated cardiac phenotype reported here.
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Affiliation(s)
- Jonas Lexow
- National Heart and Lung Institute, Heart Science Centre and Hammersmith Hospital Campus, Imperial College London, London, W12 0NN, UK
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38
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Davis J, Maillet M, Miano JM, Molkentin JD. Lost in transgenesis: a user's guide for genetically manipulating the mouse in cardiac research. Circ Res 2012; 111:761-77. [PMID: 22935533 DOI: 10.1161/circresaha.111.262717] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The advent of modern mouse genetics has benefited many fields of diseased-based research over the past 20 years, none perhaps more profoundly than cardiac biology. Indeed, the heart is now arguably one of the easiest tissues to genetically manipulate, given the availability of an ever-growing tool chest of molecular reagents/promoters and "facilitator" mouse lines. It is now possible to modify the expression of essentially any gene or partial gene product in the mouse heart at any time, either gain or loss of function. This review is designed as a handbook for the nonmouse geneticist and/or junior investigator to permit the successful manipulation of any gene or RNA product in the heart, while avoiding artifacts. In the present review, guidelines, pitfalls, and limitations are presented so that rigorous and appropriate examination of cardiac genotype-phenotype relationships can be performed. This review uses examples from the field to illustrate the vast spectrum of experimental and design details that must be considered when using genetically modified mouse models to study cardiac biology.
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Affiliation(s)
- Jennifer Davis
- Department of Pediatrics, University of Cincinnati, Howard Hughes Medical Institute, Cincinnati Children's Hospital Medical Center, 240 Albert Sabin Way, S4.409, Cincinnati, OH 45229, USA
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39
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Chen HZ, Ouseph MM, Li J, Pécot T, Chokshi V, Kent L, Bae S, Byrne M, Duran C, Comstock G, Trikha P, Mair M, Senapati S, Martin CK, Gandhi S, Wilson N, Liu B, Huang YW, Thompson JC, Raman S, Singh S, Leone M, Machiraju R, Huang K, Mo X, Fernandez S, Kalaszczynska I, Wolgemuth DJ, Sicinski P, Huang T, Jin V, Leone G. Canonical and atypical E2Fs regulate the mammalian endocycle. Nat Cell Biol 2012; 14:1192-202. [PMID: 23064266 PMCID: PMC3616487 DOI: 10.1038/ncb2595] [Citation(s) in RCA: 114] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Accepted: 09/03/2012] [Indexed: 02/06/2023]
Abstract
The endocycle is a variant cell cycle consisting of successive DNA synthesis and Gap phases that yield highly polyploid cells. Although essential for metazoan development, relatively little is known about its control or physiologic role in mammals. Using novel lineage-specific cre mice we identified two opposing arms of the E2F program, one driven by canonical transcription activation (E2F1, E2F2 and E2F3) and the other by atypical repression (E2F7 and E2F8), that converge on the regulation of endocycles in vivo. Ablation of canonical activators in the two endocycling tissues of mammals, trophoblast giant cells in the placenta and hepatocytes in the liver, augmented genome ploidy, whereas ablation of atypical repressors diminished ploidy. These two antagonistic arms coordinate the expression of a unique G2/M transcriptional program that is critical for mitosis, karyokinesis and cytokinesis. These results provide in vivo evidence for a direct role of E2F family members in regulating non-traditional cell cycles in mammals.
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Affiliation(s)
- Hui-Zi Chen
- Solid Tumor Biology Program, Department of Molecular Virology, Immunology and Medical Genetics, Department of Molecular Genetics, Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA
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Chiu-Ugalde J, Wirth EK, Klein MO, Sapin R, Fradejas-Villar N, Renko K, Schomburg L, Köhrle J, Schweizer U. Thyroid function is maintained despite increased oxidative stress in mice lacking selenoprotein biosynthesis in thyroid epithelial cells. Antioxid Redox Signal 2012; 17:902-13. [PMID: 22369680 DOI: 10.1089/ars.2011.4055] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
AIMS We have tested the hypothesis that selenium (Se)-containing antioxidative enzymes protect thyroid epithelial cells from oxidative damage associated with enzymatic production of hydrogen peroxide required for thyroid hormone biosynthesis. Thyroid epithelial cells therefore express antioxidative enzymes, including catalase, peroxiredoxins, thioredoxin reductases, and glutathione peroxidases (GPxs). The latter two enzyme families contain highly active peroxide-degrading enzymes that carry selenocysteine (Sec) in their active centers. Since low Se status has been associated with thyroid disorders, selenoproteins are considered essential for thyroid integrity and function. We have conditionally inactivated selenoprotein biosynthesis in thyrocytes by targeting Sec tRNA. RESULTS Constitutive and inducible Cre/loxP-mediated recombination of tRNA([Ser]Sec) drastically reduced activities of selenoenzymes GPx and type I-deiodinase in thyroid extracts. Immunohistochemical staining revealed increased 4-hydroxynonenal and 3-nitro-tyrosine levels consistent with increased oxidative stress. However, gross thyroid morphology remained intact for at least 6 months after recombination. Circulating thyroid hormone levels remained normal in mutant mice, while thyrotropin (TSH) levels were moderately elevated. Challenging mutant mice with low iodine diet increased TSH, but did not lead to destruction of selenoprotein-deficient thyroids. INNOVATION This is the first report probing the assumed physiological roles of selenoproteins in the thyroid using a genetic loss-of-function approach. CONCLUSION We conclude that selenoproteins protect thyrocytes from oxidative damage and modulate thyroid hormone biosynthesis, but are not essential for thyrocyte survival.
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Affiliation(s)
- Jazmin Chiu-Ugalde
- Institut für Experimentelle Endokrinologie, Charité-Universitätsmedizin Berlin, Germany
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Cano CE, Sandí MJ, Hamidi T, Calvo EL, Turrini O, Bartholin L, Loncle C, Secq V, Garcia S, Lomberk G, Kroemer G, Urrutia R, Iovanna JL. Homotypic cell cannibalism, a cell-death process regulated by the nuclear protein 1, opposes to metastasis in pancreatic cancer. EMBO Mol Med 2012; 4:964-79. [PMID: 22821859 PMCID: PMC3491828 DOI: 10.1002/emmm.201201255] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Revised: 06/15/2012] [Accepted: 06/20/2012] [Indexed: 01/06/2023] Open
Abstract
Pancreatic adenocarcinoma (PDAC) is an extremely deadly disease for which all treatments available have failed to improve life expectancy significantly. This may be explained by the high metastatic potential of PDAC cells, which results from their dedifferentiation towards a mesenchymal phenotype. Some PDAC present cell-in-cell structures whose origin and significance are currently unknown. We show here that cell-in-cells form after homotypic cell cannibalism (HoCC). We found PDAC patients whose tumours display HoCC develop less metastasis than those without. In vitro, HoCC was promoted by inactivation of the nuclear protein 1 (Nupr1), and was enhanced by treatment with transforming growth factor β. HoCC ends with death of PDAC cells, consistent with a metastasis suppressor role for this phenomenon. Hence, our data indicates a protective role for HoCC in PDAC and identifies Nupr1 as a molecular regulator of this process.
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Weber T, Renzland I, Baur M, Mönks S, Herrmann E, Huppert V, Nürnberg F, Schönig K, Bartsch D. Tetracycline inducible gene manipulation in serotonergic neurons. PLoS One 2012; 7:e38193. [PMID: 22693598 PMCID: PMC3364967 DOI: 10.1371/journal.pone.0038193] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 05/01/2012] [Indexed: 01/01/2023] Open
Abstract
The serotonergic (5-HT) neuronal system has important and diverse physiological functions throughout development and adulthood. Its dysregulation during development or later in adulthood has been implicated in many neuropsychiatric disorders. Transgenic animal models designed to study the contribution of serotonergic susceptibility genes to a pathological phenotype should ideally allow to study candidate gene overexpression or gene knockout selectively in serotonergic neurons at any desired time during life. For this purpose, conditional expression systems such as the tet-system are preferable. Here, we generated a transactivator (tTA) mouse line (TPH2-tTA) that allows temporal and spatial control of tetracycline (Ptet) controlled transgene expression as well as gene deletion in 5-HT neurons. The tTA cDNA was inserted into a 196 kb PAC containing a genomic mouse Tph2 fragment (177 kb) by homologous recombination in E. coli. For functional analysis of Ptet-controlled transgene expression, TPH2-tTA mice were crossed to a Ptet-regulated lacZ reporter line (Ptet-nLacZ). In adult double-transgenic TPH2-tTA/Ptet-nLacZ mice, TPH2-tTA founder line L62-20 showed strong serotonergic β-galactosidase expression which could be completely suppressed with doxycycline (Dox). Furthermore, Ptet-regulated gene expression could be reversibly activated or inactivated when Dox was either withdrawn or added to the system. For functional analysis of Ptet-controlled, Cre-mediated gene deletion, TPH2-tTA mice (L62-20) were crossed to double transgenic Ptet-Cre/R26R reporter mice to generate TPH2-tTA/Ptet-Cre/R26R mice. Without Dox, 5-HT specific recombination started at E12.5. With permanent Dox administration, Ptet-controlled Cre-mediated recombination was absent. Dox withdrawal either postnatally or during adulthood induced efficient recombination in serotonergic neurons of all raphe nuclei, respectively. In the enteric nervous system, recombination could not be detected. We generated a transgenic mouse tTA line (TPH2-tTA) which allows both inducible and reversible transgene expression and inducible Cre-mediated gene deletion selectively in 5-HT neurons throughout life. This will allow precise delineation of serotonergic gene functions during development and adulthood.
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Affiliation(s)
- Tillmann Weber
- Department of Molecular Biology, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Mannheim, Germany
- Department of Addictive Behavior and Addiction Medicine, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Mannheim, Germany
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Mannheim, Germany
| | - Insa Renzland
- Department of Molecular Biology, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Mannheim, Germany
| | - Max Baur
- Department of Molecular Biology, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Mannheim, Germany
| | - Simon Mönks
- Department of Molecular Biology, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Mannheim, Germany
| | - Elke Herrmann
- Department of Molecular Biology, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Mannheim, Germany
| | - Verena Huppert
- Department of Molecular Biology, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Mannheim, Germany
| | - Frank Nürnberg
- Institute for Applied Mathematics, Faculty for Informatics, Mannheim University of Applied Sciences, Mannheim, Germany
| | - Kai Schönig
- Department of Molecular Biology, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Mannheim, Germany
| | - Dusan Bartsch
- Department of Molecular Biology, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Mannheim, Germany
- * E-mail:
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Pfrieger FW, Slezak M. Genetic approaches to study glial cells in the rodent brain. Glia 2011; 60:681-701. [PMID: 22162024 DOI: 10.1002/glia.22283] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Accepted: 11/18/2011] [Indexed: 01/02/2023]
Abstract
The development, function, and pathology of the brain depend on interactions of neurons and different types of glial cells, namely astrocytes, oligodendrocytes, microglia, and ependymal cells. Understanding neuron-glia interactions in vivo requires dedicated experimental approaches to manipulate each cell type independently. In this review, we first summarize techniques that allow for cell-specific gene modification including targeted mutagenesis and viral transduction. In the second part, we describe the genetic models that allow to target the main glial cell types in the central nervous system. The existing arsenal of approaches to study glial cells in vivo and its expansion in the future are key to understand neuron-glia interactions under normal and pathologic conditions.
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Affiliation(s)
- Frank W Pfrieger
- CNRS UPR 3212, University of Strasbourg, Institute of Cellular and Integrative Neurosciences (INCI), 67084 Strasbourg, France.
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Horstkotte J, Perisic T, Schneider M, Lange P, Schroeder M, Kiermayer C, Hinkel R, Ziegler T, Mandal PK, David R, Schulz S, Schmitt S, Widder J, Sinowatz F, Becker BF, Bauersachs J, Naebauer M, Franz WM, Jeremias I, Brielmeier M, Zischka H, Conrad M, Kupatt C. Mitochondrial thioredoxin reductase is essential for early postischemic myocardial protection. Circulation 2011; 124:2892-902. [PMID: 22144571 DOI: 10.1161/circulationaha.111.059253] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Excessive formation of reactive oxygen species contributes to tissue injury and functional deterioration after myocardial ischemia/reperfusion. Especially, mitochondrial reactive oxygen species are capable of opening the mitochondrial permeability transition pore, a harmful event in cardiac ischemia/reperfusion. Thioredoxins are key players in the cardiac defense against oxidative stress. Mutations in the mitochondrial thioredoxin reductase (thioredoxin reductase-2, Txnrd2) gene have been recently identified to cause dilated cardiomyopathy in patients. Here, we investigated whether mitochondrial thioredoxin reductase is protective against myocardial ischemia/reperfusion injury. METHODS AND RESULTS In mice, α-MHC-restricted Cre-mediated Txnrd2 deficiency, induced by tamoxifen (Txnrd2-/-ic), aggravated systolic dysfunction and cardiomyocyte cell death after ischemia (90 minutes) and reperfusion (24 hours). Txnrd2-/-ic was accompanied by a loss of mitochondrial integrity and function, which was resolved on pretreatment with the reactive oxygen species scavenger N-acetylcysteine and the mitochondrial permeability transition pore blocker cyclosporin A. Likewise, Txnrd2 deletion in embryonic endothelial precursor cells and embryonic stem cell-derived cardiomyocytes, as well as introduction of Txnrd2-shRNA into adult HL-1 cardiomyocytes, increased cell death on hypoxia and reoxygenation, unless N-acetylcysteine was coadministered. CONCLUSIONS We report that Txnrd2 exerts a crucial function during postischemic reperfusion via thiol regeneration. The efficacy of cyclosporin A in cardiac Txnrd2 deficiency may indicate a role for Txnrd2 in reducing mitochondrial reactive oxygen species, thereby preventing opening of the mitochondrial permeability transition pore.
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Affiliation(s)
- Jan Horstkotte
- Medizinische Klinik und Poliklinik I, Munich Heart Alliance, Klinikum Grosshadern of the Ludwig Maximilians-University, Munich, Germany
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Miró-Murillo M, Elorza A, Soro-Arnáiz I, Albacete-Albacete L, Ordoñez A, Balsa E, Vara-Vega A, Vázquez S, Fuertes E, Fernández-Criado C, Landázuri MO, Aragonés J. Acute Vhl gene inactivation induces cardiac HIF-dependent erythropoietin gene expression. PLoS One 2011; 6:e22589. [PMID: 21811636 PMCID: PMC3141062 DOI: 10.1371/journal.pone.0022589] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Accepted: 06/29/2011] [Indexed: 01/01/2023] Open
Abstract
Von Hippel Lindau (Vhl) gene inactivation results in embryonic lethality. The consequences of its inactivation in adult mice, and of the ensuing activation of the hypoxia-inducible factors (HIFs), have been explored mainly in a tissue-specific manner. This mid-gestation lethality can be also circumvented by using a floxed Vhl allele in combination with an ubiquous tamoxifen-inducible recombinase Cre-ERT2. Here, we characterize a widespread reduction in Vhl gene expression in Vhlfloxed-UBC-Cre-ERT2 adult mice after dietary tamoxifen administration, a convenient route of administration that has yet to be fully characterized for global gene inactivation. Vhl gene inactivation rapidly resulted in a marked splenomegaly and skin erythema, accompanied by renal and hepatic induction of the erythropoietin (Epo) gene, indicative of the in vivo activation of the oxygen sensing HIF pathway. We show that acute Vhl gene inactivation also induced Epo gene expression in the heart, revealing cardiac tissue to be an extra-renal source of EPO. Indeed, primary cardiomyocytes and HL-1 cardiac cells both induce Epo gene expression when exposed to low O2 tension in a HIF-dependent manner. Thus, as well as demonstrating the potential of dietary tamoxifen administration for gene inactivation studies in UBC-Cre-ERT2 mouse lines, this data provides evidence of a cardiac oxygen-sensing VHL/HIF/EPO pathway in adult mice.
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Affiliation(s)
| | - Ainara Elorza
- Department of Immunology, Hospital of La Princesa, Sanitary Research Institute Princesa (IP), Autonomous University of Madrid, Madrid, Spain
| | - Inés Soro-Arnáiz
- Department of Immunology, Hospital of La Princesa, Sanitary Research Institute Princesa (IP), Autonomous University of Madrid, Madrid, Spain
| | - Lucas Albacete-Albacete
- Department of Immunology, Hospital of La Princesa, Sanitary Research Institute Princesa (IP), Autonomous University of Madrid, Madrid, Spain
| | - Angel Ordoñez
- Department of Immunology, Hospital of La Princesa, Sanitary Research Institute Princesa (IP), Autonomous University of Madrid, Madrid, Spain
| | - Eduardo Balsa
- Department of Immunology, Hospital of La Princesa, Sanitary Research Institute Princesa (IP), Autonomous University of Madrid, Madrid, Spain
| | - Alicia Vara-Vega
- Department of Immunology, Hospital of La Princesa, Sanitary Research Institute Princesa (IP), Autonomous University of Madrid, Madrid, Spain
| | - Silvia Vázquez
- Department of Immunology, Hospital of La Princesa, Sanitary Research Institute Princesa (IP), Autonomous University of Madrid, Madrid, Spain
| | - Esther Fuertes
- Department of Immunology, Hospital of La Princesa, Sanitary Research Institute Princesa (IP), Autonomous University of Madrid, Madrid, Spain
| | | | - Manuel O. Landázuri
- Department of Immunology, Hospital of La Princesa, Sanitary Research Institute Princesa (IP), Autonomous University of Madrid, Madrid, Spain
| | - Julián Aragonés
- Department of Immunology, Hospital of La Princesa, Sanitary Research Institute Princesa (IP), Autonomous University of Madrid, Madrid, Spain
- * E-mail:
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Endothelial and macrophage-specific deficiency of P38α MAPK does not affect the pathogenesis of atherosclerosis in ApoE-/- mice. PLoS One 2011; 6:e21055. [PMID: 21695272 PMCID: PMC3111465 DOI: 10.1371/journal.pone.0021055] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2010] [Accepted: 05/19/2011] [Indexed: 11/19/2022] Open
Abstract
Background The p38α Mitogen-Activated Protein Kinase (MAPK) regulates stress- and inflammation-induced cellular responses. Factors implicated in the development of atherosclerosis including modified low-density lipoprotein (LDL), cytokines and even shear stress induce p38 activation in endothelial cells and macrophages, which may be important for plaque formation. This study investigates the effects of endothelial- and macrophage-specific deficiency of p38α in atherosclerosis development, in Apolipoprotein E deficient (ApoE−/−) mice. Methodology/Principal Findings ApoE−/− mice with macrophage or endothelial cell-specific p38α deficiency were fed a high cholesterol diet (HCD) for 10 weeks and atherosclerosis development was assessed by histological and molecular methods. Surprisingly, although p38α-deficiency strongly attenuated oxidized LDL-induced expression of molecules responsible for monocyte recruitment in endothelial cell cultures in vitro, endothelial-specific p38α ablation in vivo did not affect atherosclerosis development. Similarly, macrophage specific deletion of p38α did not affect atherosclerotic plaque development in ApoE−/− mice. Conclusions Although previous studies implicated p38α signaling in atherosclerosis, our in vivo experiments suggest that p38α function in endothelial cells and macrophages does not play an important role in atherosclerotic plaque formation in ApoE deficient mice.
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Abstract
Inducible transgenic mouse models allow for the activation of genes in specific cells and tissues at specific times. Expression levels are dependent on the dose of the agent administered. Effective experimental models are characterized by low background levels of the regulated gene and induction to high levels with sub-physiological levels of inducing agents. The most commonly used methods to control gene expression in mouse models are based on the tet-operon/repressor bi-transgenic system and the estrogen receptor (ER) ligand-binding domain. Less commonly used systems to control gene expression in transgenic mice take advantage of the ligand-binding domain of the progesterone receptor, and the lac and GAL4 inducible systems. The tetracycline-regulated transgenic models are typically designed to activate the expression of the gene of interest in a specific cell type at a specific point in time. The ER is most commonly fused with Cre recombinase, although it can be used with transcription factors, kinases, etc., that are active in the nucleus. Cre-ER transgenes allow for the induction of recombinase activity in specific cells at defined time points. Cre recombinase is most often found in combination with conditional alleles to inactivate gene expression. When used for gene activation, Cre removes stop cassettes from transgenes and thus allows the expression of reporter or other molecules. Thus, the tetracycline-regulated and Cre-ER systems are complementary in mouse models, with utility in the cell-specific activation and inactivation of gene expression.
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Affiliation(s)
- Thomas L Saunders
- Transgenic Animal Model Core, University of Michigan, Ann Arbor, MI, USA.
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Abstract
Gene targeting in ES cells is extensively used to generate designed mouse mutants and to study gene function in vivo. Knockout mice that harbor a null allele in their germline provide appropriate genetic models of inherited diseases and often exhibit embryonic or early postnatal lethality. To study gene function in adult mice and in selected cell types, a refined strategy for conditional gene inactivation has been developed that relies on the DNA recombinase Cre and its recognition (loxP) sites. For conditional mutagenesis, a target gene is modified by the insertion of two loxP sites that enable to excise the flanked (floxed) gene segment through Cre-mediated recombination. Conditional mutant mice are obtained by crossing the floxed strain with a Cre transgenic line such that the target gene becomes inactivated in vivo within the expression domain of Cre. A large collection of Cre transgenic lines has been generated over time and can be used in a combinatorial manner to achieve gene inactivation in many different cell types. A growing number of CreER(T2) transgenic mice further allows for inducible inactivation of floxed alleles in adult mice upon administration of tamoxifen. This chapter covers the design and construction of loxP flanked alleles and refers to the vectors, ES cells, and mice generated by the European conditional mouse mutagenesis (EUCOMM) project. We further describe the design and use of Cre and CreER(T2) transgenic mice and a convenient breeding strategy to raise conditional mutants and controls for phenotype analysis.
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Hougen K, Aronsen JM, Stokke MK, Enger U, Nygard S, Andersson KB, Christensen G, Sejersted OM, Sjaastad I. Cre-loxP DNA recombination is possible with only minimal unspecific transcriptional changes and without cardiomyopathy in Tg(alphaMHC-MerCreMer) mice. Am J Physiol Heart Circ Physiol 2010; 299:H1671-8. [PMID: 20802136 DOI: 10.1152/ajpheart.01155.2009] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cre-loxP technology for conditional gene inactivation is a powerful tool in cardiovascular research. Induction of gene inactivation can be carried out by per oral or intraperitoneal tamoxifen administration. Unintended transient cardiomyopathy following tamoxifen administration for gene inactivation has recently been reported. We aimed to develop a protocol for tamoxifen-induced gene inactivation with minimal effects on gene transcription and in vivo cardiac function, allowing studies of acute loss of the targeted gene. In mRNA microarrays, 35% of the 34,760 examined genes were significantly regulated in MCM(+/0) compared with wild type. In MCM(+/0), we found a correlation between tamoxifen dose and degree of gene regulation. Comparing one and four intraperitoneal injections of 40 mg·kg(-1)·day(-1) tamoxifen, regulated genes were reduced to 1/5 in the single injection group. Pronounced alteration in protein abundance and acute cardiomyopathy were observed after the four-injection protocols but not the one-injection protocol. For verification of gene inactivation following one injection of tamoxifen, this protocol was applied to MCM(+/0)/Serca2(fl/fl). Serca2 mRNA levels and protein abundance followed the same pattern of decline with one and four tamoxifen injections. The presence of the MCM transgene induced major alterations of gene expression while administration of tamoxifen induced additional but less gene regulation. Thus nonfloxed MCM(+/0) should be considered as controls for mice that carry both a floxed gene of interest and the MCM transgene. One single tamoxifen injection administered to MCM(+/0)/Serca2(fl/fl) was sufficient for target gene inactivation, without acute cardiomyopathy, allowing acute studies subsequent to gene inactivation.
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Affiliation(s)
- Karina Hougen
- Institute for Experimental Medical Research, Oslo Univ. Hospital Ullevål, Kirkevn 166, 0407 Oslo, Norway.
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Deletion of TDP-43 down-regulates Tbc1d1, a gene linked to obesity, and alters body fat metabolism. Proc Natl Acad Sci U S A 2010; 107:16320-4. [PMID: 20660762 DOI: 10.1073/pnas.1002176107] [Citation(s) in RCA: 225] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Tat activating regulatory DNA-binding protein (Tardbp or TDP-43), a highly conserved metazoan DNA/RNA binding protein thought to be involved in RNA transcription and splicing, has been linked to the pathophysiology of amyotrophic lateral sclerosis and frontotemporal lobar degeneration and is essential for early embryonic development. However, neither the physiological role of TDP-43 in the adult nor its downstream targets are well defined. To address these questions, we developed conditional Tardbp-KO mice and embryonic stem (ES) cell models. Here, we show that postnatal deletion of Tardbp in mice caused dramatic loss of body fat followed by rapid death. Moreover, conditional Tardbp-KO ES cells failed to proliferate. Importantly, high-throughput DNA sequencing analysis on the transcriptome of ES cells lacking Tardbp revealed a set of downstream targets of TDP-43. We show that Tbc1d1, a gene known to mediate leanness and linked to obesity, is down-regulated in the absence of TDP-43. Collectively, our results establish that TDP-43 is critical for fat metabolism and ES cell survival.
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