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A Potential Role of the CD47/SIRPalpha Axis in COVID-19 Pathogenesis. Curr Issues Mol Biol 2021; 43:1212-1225. [PMID: 34698067 PMCID: PMC8929144 DOI: 10.3390/cimb43030086] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 09/16/2021] [Accepted: 09/17/2021] [Indexed: 12/15/2022] Open
Abstract
The coronavirus SARS-CoV-2 is the cause of the ongoing COVID-19 pandemic. Most SARS-CoV-2 infections are mild or even asymptomatic. However, a small fraction of infected individuals develops severe, life-threatening disease, which is caused by an uncontrolled immune response resulting in hyperinflammation. However, the factors predisposing individuals to severe disease remain poorly understood. Here, we show that levels of CD47, which is known to mediate immune escape in cancer and virus-infected cells, are elevated in SARS-CoV-2-infected Caco-2 cells, Calu-3 cells, and air-liquid interface cultures of primary human bronchial epithelial cells. Moreover, SARS-CoV-2 infection increases SIRPalpha levels, the binding partner of CD47, on primary human monocytes. Systematic literature searches further indicated that known risk factors such as older age and diabetes are associated with increased CD47 levels. High CD47 levels contribute to vascular disease, vasoconstriction, and hypertension, conditions that may predispose SARS-CoV-2-infected individuals to COVID-19-related complications such as pulmonary hypertension, lung fibrosis, myocardial injury, stroke, and acute kidney injury. Hence, age-related and virus-induced CD47 expression is a candidate mechanism potentially contributing to severe COVID-19, as well as a therapeutic target, which may be addressed by antibodies and small molecules. Further research will be needed to investigate the potential involvement of CD47 and SIRPalpha in COVID-19 pathology. Our data should encourage other research groups to consider the potential relevance of the CD47/ SIRPalpha axis in their COVID-19 research.
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Gao L, Yang TT, Zhang JS, Liu HX, Cai DC, Wang LT, Wang J, Li XW, Gao K, Zhang SY, Cao YJ, Ji XX, Yang MM, Han B, Wang S, He L, Nie XY, Liu DM, Meng G, He CY. THBS1/CD47 Modulates the Interaction of γ-Catenin With E-Cadherin and Participates in Epithelial-Mesenchymal Transformation in Lipid Nephrotoxicity. Front Cell Dev Biol 2021; 8:601521. [PMID: 33681182 PMCID: PMC7930485 DOI: 10.3389/fcell.2020.601521] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 12/31/2020] [Indexed: 12/28/2022] Open
Abstract
Hyperlipidemia, an important risk factor for cardiovascular and end-stage renal diseases, often aggravates renal injury and compromises kidney function. Here, histological analysis of human kidney samples revealed that high lipid levels induced the development of renal fibrosis. To elucidate the mechanism underlying lipid nephrotoxicity, we used two types of mouse models (Apoe−/− and C57BL/6 mice fed a 45 and 60% high-fat diet, respectively). Histological analysis of kidney tissues revealed high-lipid-induced renal fibrosis and inflammation; this was confirmed by examining fibrotic and inflammatory marker expression using Western blotting and real-time polymerase chain reaction. Oxidized low-density lipoprotein (OX-LDL) significantly induced the fibrotic response in HK-2 tubular epithelial cells. RNA-sequencing and Gene Ontology analysis of differentially expressed mRNAs in OX-LDL-treated HK-2 tubular epithelial cells and real-time PCR validation in Apoe−/− mice showed that the expression of thrombospondin-1 (THBS1) in the high-fat group was significantly higher than that of the other top known genes, along with significant overexpression of its receptor CD47. THBS1 knockdown cells verified its relation to OX-LDL-induced fibrosis and inflammation. Liquid chromatography tandem mass spectrometry and STRING functional protein association network analyses predicted that THBS1/CD47 modulated the interaction between γ-catenin and E-cadherin and was involved in epithelial–mesenchymal transition, which was supported by immunoprecipitation and immunohistochemistry. CD47 downregulation following transfection with small-hairpin RNA in OX-LDL-treated tubular epithelial cells and treatment with anti-CD47 antibody restored the expression of E-cadherin and attenuated renal injury, fibrosis, and inflammatory response in OX-LDL-treated cells and in type 2 diabetes mellitus. These findings indicate that CD47 may serve as a potential therapeutic target in long-term lipid-induced kidney injury.
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Affiliation(s)
- Li Gao
- State Key Laboratory of Natural Medicines, Department of Pharmacology, China Pharmaceutical University, Nanjing, China
| | - Ting-Ting Yang
- State Key Laboratory of Natural Medicines, Department of Pharmacology, China Pharmaceutical University, Nanjing, China
| | - Jun-Sheng Zhang
- Pathophysiology Department, The Fourth Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Hong-Xia Liu
- State Key Laboratory of Natural Medicines, Department of Pharmacology, China Pharmaceutical University, Nanjing, China
| | - Dong-Cheng Cai
- State Key Laboratory of Natural Medicines, Department of Pharmacology, China Pharmaceutical University, Nanjing, China
| | - Lin-Tao Wang
- State Key Laboratory of Natural Medicines, Department of Pharmacology, China Pharmaceutical University, Nanjing, China
| | - Jing Wang
- State Key Laboratory of Natural Medicines, Department of Pharmacology, China Pharmaceutical University, Nanjing, China
| | - Xin-Wei Li
- State Key Laboratory of Natural Medicines, Department of Pharmacology, China Pharmaceutical University, Nanjing, China
| | - Kun Gao
- State Key Laboratory of Natural Medicines, Department of Pharmacology, China Pharmaceutical University, Nanjing, China
| | - Su-Ya Zhang
- State Key Laboratory of Natural Medicines, Department of Pharmacology, China Pharmaceutical University, Nanjing, China
| | - Yu-Jia Cao
- State Key Laboratory of Natural Medicines, Department of Pharmacology, China Pharmaceutical University, Nanjing, China
| | - Xiao-Xia Ji
- State Key Laboratory of Natural Medicines, Department of Pharmacology, China Pharmaceutical University, Nanjing, China
| | - Miao-Miao Yang
- Pathophysiology Department, The Fourth Affiliated Hospital of Anhui Medical University, Hefei, China.,Anhui Yizhiben Center for Judicial Expertise, Hefei, China
| | - Biao Han
- Pathophysiology Department, The Fourth Affiliated Hospital of Anhui Medical University, Hefei, China.,Anhui Yizhiben Center for Judicial Expertise, Hefei, China
| | - Sheng Wang
- Center for Scientific Research of Anhui Medical University, Hefei, China
| | - Lu He
- State Key Laboratory of Natural Medicines, Department of Pharmacology, China Pharmaceutical University, Nanjing, China
| | - Xiao-Yan Nie
- State Key Laboratory of Natural Medicines, Department of Pharmacology, China Pharmaceutical University, Nanjing, China
| | - Dan-Mei Liu
- State Key Laboratory of Natural Medicines, Department of Pharmacology, China Pharmaceutical University, Nanjing, China
| | - Gang Meng
- Pathophysiology Department, The Fourth Affiliated Hospital of Anhui Medical University, Hefei, China.,Anhui Yizhiben Center for Judicial Expertise, Hefei, China
| | - Chao-Yong He
- State Key Laboratory of Natural Medicines, Department of Pharmacology, China Pharmaceutical University, Nanjing, China
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Yue H, Febbraio M, Klenotic PA, Kennedy DJ, Wu Y, Chen S, Gohara AF, Li O, Belcher A, Kuang B, McIntyre TM, Silverstein RL, Li W. CD36 Enhances Vascular Smooth Muscle Cell Proliferation and Development of Neointimal Hyperplasia. Arterioscler Thromb Vasc Biol 2019; 39:263-275. [PMID: 30567481 DOI: 10.1161/atvbaha.118.312186] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Objective- Dysregulated proliferation of vascular smooth muscle cells (VSMC) plays an essential role in neointimal hyperplasia. CD36 functions critically in atherogenesis and thrombosis. We hypothesize that CD36 regulates VSMC proliferation and contributes to the development of obstructive vascular diseases. Approach and Results- We found by immunofluorescent staining that CD36 was highly expressed in human vessels with obstructive diseases. Using guidewire-induced carotid artery injury and shear stress-induced intima thickening models, we compared neointimal hyperplasia in Apoe-/-, Cd36-/- /Apoe-/-, and CD36 specifically deleted in VSMC (VSMC cd36-/-) mice. CD36 deficiency, either global or VSMC-specific, dramatically reduced injury-induced neointimal thickening. Correspondingly, carotid artery blood flow was significantly increased in Cd36-/- /Apoe-/- compared with Apoe-/- mice. In cultured VSMCs from thoracic aorta of wild-type and Cd36-/- mice, we found that loss of CD36 significantly decreased serum-stimulated proliferation and increased cell populations in S phase, suggesting that CD36 is necessary for VSMC S/G2-M-phase transition. Treatment of VSMCs with a TSR (thrombospondin type 1 repeat) peptide significantly increased wild-type, but not Cd36-/- VSMC proliferation. TSR or serum treatment significantly increased cyclin A expression in wild-type, but not in Cd36-/- VSMCs. STAT3 (signal transducer and activator of transcription), which reportedly enhances both VSMC differentiation and maturation, was higher in Cd36-/- VSMCs. CD36 deficiency significantly decreased expression of Col1A1 (type 1 collagen A1 chain) and TGF-β1 (transforming growth factor beta 1), and increased expression of contractile proteins, including calponin 1 and smooth muscle α actin, and dramatically increased cell contraction. Conclusions- CD36 promotes VSMC proliferation via upregulation of cyclin A expression that contributes to the development of neointimal hyperplasia, collagen deposition, and obstructive vascular diseases.
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Affiliation(s)
- Hong Yue
- From the Department of Biomedical Sciences, Marshall University Joan C. Edwards School of Medicine, Huntington, WV (H.Y., A.B., W.L.)
| | - Maria Febbraio
- Department of Dentistry, University of Alberta, Edmonton, Canada (M.F.)
| | - Philip A Klenotic
- Case Cardiovascular Research Institute, Case Western Reserve University School of Medicine, Harrington Heart and Vascular Institute, University Hospitals Case Medical Center, Cleveland, OH (P.A.K.)
| | | | - Yueheng Wu
- Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of South China Structural Heart Disease, Guangdong General Hospital, Guangdong Academy of Medical Sciences, China (Y.W., S.C.)
| | - Shaoxian Chen
- Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of South China Structural Heart Disease, Guangdong General Hospital, Guangdong Academy of Medical Sciences, China (Y.W., S.C.)
| | - Amira F Gohara
- Department of Pathology (A.F.G.), University of Toledo, OH
| | - Oliver Li
- Marshall University Marshall Institute for Interdisciplinary Research, Huntington, WV (O.L., W.L.)
| | - Adam Belcher
- From the Department of Biomedical Sciences, Marshall University Joan C. Edwards School of Medicine, Huntington, WV (H.Y., A.B., W.L.)
| | - Bin Kuang
- Department of Plastic and Peripheral Vascular Surgery, Guangdong General Hospital, China (B.K.)
| | - Thomas M McIntyre
- Departments of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, OH (T.M.M.).,Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, OH (T.M.M.)
| | - Roy L Silverstein
- Department of Medicine, Medical College of Wisconsin, Milwaukee (R.L.S.)
| | - Wei Li
- From the Department of Biomedical Sciences, Marshall University Joan C. Edwards School of Medicine, Huntington, WV (H.Y., A.B., W.L.)
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Maile LA, Busby WH, Gollahon KA, Flowers W, Garbacik N, Garbacik S, Stewart K, Nichols T, Bellinger D, Patel A, Dunbar P, Medlin M, Clemmons D. Blocking ligand occupancy of the αVβ3 integrin inhibits the development of nephropathy in diabetic pigs. Endocrinology 2014; 155:4665-75. [PMID: 25171599 PMCID: PMC4239428 DOI: 10.1210/en.2014-1318] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Hyperglycemia stimulates secretion of αVβ3 ligands from vascular cells, including endothelial cells, resulting in activation of the αVβ3 integrin. This study determined whether blocking ligand occupancy of αVβ3 would inhibit the development of diabetic nephropathy. Ten diabetic pigs received an F(ab)2 fragment of an antibody directed against the extracellular domain of the β3-subunit, and 10 received a control IgG F(ab)2 for 18 weeks. Nondiabetic pigs excreted 115 ± 50 μg of protein/mg creatinine compared with control F(ab)2-treated diabetic animals (218 ± 57 μg/mg), whereas diabetic animals treated with the anti-β3 F(ab)2 excreted 119 ± 55 μg/mg (P < .05). Mesangial volume/glomerular volume increased to 21 ± 2.4% in control-treated diabetic animals compared with 14 ± 2.8% (P < .01) in animals treated with active antibody. Diabetic animals treated with control F(ab)2 had significantly less glomerular podocin staining compared with nondiabetic animals, and this decrease was attenuated by treatment with anti-β3 F(ab)2. Glomerular basement membrane thickness was increased in the control, F(ab)2-treated diabetic animals (212 ± 14 nm) compared with nondiabetic animals (170 ± 8.8 nm), but it was unchanged (159.9 ± 16.4 nm) in animals receiving anti-β3 F(ab)2. Podocyte foot process width was greater in control, F(ab)2-treated, animals (502 ± 34 nm) compared with animals treated with the anti-β3 F(ab)2 (357 ± 47 nm, P < .05). Renal β3 tyrosine phosphorylation decreased from 13 934 ± 6437 to 6730 ± 1524 (P < .01) scanning units in the anti-β3-treated group. We conclude that administration of an antibody that inhibits activation of the β3-subunit of αVβ3 that is induced by hyperglycemia attenuates proteinuria and early histologic changes of diabetic nephropathy, suggesting that it may have utility in preventing the progression of this disease complication.
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Affiliation(s)
- Laura A Maile
- Department of Medicine (L.A.M., W.H.B., K.A.G., T.N., D.B., A.P., P.D., M.M., D.C.), University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599; and Department of Animal Science (W.F., N.G., S.G., K.S.), North Carolina State University, Raleigh, North Carolina 27695
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Soto-Pantoja DR, Stein EV, Rogers NM, Sharifi-Sanjani M, Isenberg JS, Roberts DD. Therapeutic opportunities for targeting the ubiquitous cell surface receptor CD47. Expert Opin Ther Targets 2013; 17:89-103. [PMID: 23101472 PMCID: PMC3564224 DOI: 10.1517/14728222.2013.733699] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION CD47 is a ubiquitously expressed cell surface receptor that serves as a counter-receptor for SIRPα in recognition of self by the innate immune system. Independently, CD47 also functions as an important signaling receptor for regulating cell responses to stress. AREAS COVERED We review the expression, molecular interactions, and pathophysiological functions of CD47 in the cardiovascular and immune systems. CD47 was first identified as a potential tumor marker, and we examine recent evidence that its dysregulation contributes to cancer progression and evasion of anti-tumor immunity. We further discuss therapeutic strategies for enhancing or inhibiting CD47 signaling and applications of such agents in preclinical models of ischemia and ischemia/reperfusion injuries, organ transplantation, pulmonary hypertension, radioprotection, and cancer. EXPERT OPINION Ongoing studies are revealing a central role of CD47 for conveying signals from the extracellular microenvironment that limit cell and tissue survival upon exposure to various types of stress. Based on this key function, therapeutics targeting CD47 or its ligands thrombospondin-1 and SIRPα could have broad applications spanning reconstructive surgery, engineering of tissues and biocompatible surfaces, vascular diseases, diabetes, organ transplantation, radiation injuries, inflammatory diseases, and cancer.
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Affiliation(s)
- David R. Soto-Pantoja
- Cancer Research Training Award Fellow, Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-1500
| | - Erica V. Stein
- Predoctoral Cancer Research Training Award Fellow, Laboratoryof Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-1500 and Microbiology and Immunology Program of the Institute for Biomedical Sciences, Departments of Microbiology, Immunology and Tropical Medicine, George Washington University, 2300 Eye St., N.W., Ross Hall, Washington, D.C. 20037
| | - Natasha M. Rogers
- Visiting Research Fellow, Division of Pulmonary Allergy and Critical Care Medicine, Vascular Medicine Institute, University of Pittsburgh School of Medicine, E1240 Biomedical Science Tower, Room E1200, 200 Lothrop Street, Pittsburgh, PA 15261
| | - Maryam Sharifi-Sanjani
- Post-doctoral Fellow, Division of Pulmonary Allergy and Critical Care Medicine, Vascular Medicine Institute, University of Pittsburgh School of Medicine, E1240 Biomedical Science Tower, Room E1200, 200 Lothrop Street, Pittsburgh, PA 15261
| | - Jeffrey S. Isenberg
- Associate Professor of Medicine, Division of Pulmonary Allergy and Critical Care Medicine, Vascular Medicine Institute, University of Pittsburgh School of Medicine, E1240 Biomedical Science Tower, Room E1258, 200 Lothrop Street, Pittsburgh, PA 15261
| | - David D. Roberts
- Chief, Biochemical Pathology Section, Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Building 10 Room 2A33, Bethesda, MD 20892-1500
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Navarro-Alvarez N, Yang YG. CD47: a new player in phagocytosis and xenograft rejection. Cell Mol Immunol 2011; 8:285-8. [PMID: 21258362 DOI: 10.1038/cmi.2010.83] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Organ transplantation is limited by the availability of human donor organs. The transplantation of organs and tissues from other species (xenotransplantation) would supply an unlimited number of organs and offer many other advantages for which the pig has been identified as the most suitable source. However, the robust immune responses to xenografts remain a major obstacle to clinical application of xenotransplantation. The more vigorous xenograft rejection relative to allograft rejection is largely accounted for by the extensive genetic disparities between the donor and recipient. Xenografts activate host immunity not only by expressing immunogenic xenoantigens that provide the targets for immune recognition and rejection, but also by lacking ligands for the host immune inhibitory receptors. This review is focused on recent findings regarding the role of CD47, a ligand of an immune inhibitory receptor, signal regulatory protein alpha (SIRPα), in phagocytosis and xenograft rejection.
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Affiliation(s)
- Nalu Navarro-Alvarez
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, USA
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Liao PL, Cheng YW, Li CH, Wang YT, Kang JJ. 7-Ketocholesterol and cholesterol-5α,6α-epoxide induce smooth muscle cell migration and proliferation through the epidermal growth factor receptor/phosphoinositide 3-kinase/Akt signaling pathways. Toxicol Lett 2010; 197:88-96. [DOI: 10.1016/j.toxlet.2010.05.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2010] [Revised: 04/10/2010] [Accepted: 05/04/2010] [Indexed: 12/28/2022]
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Levitan I, Volkov S, Subbaiah PV. Oxidized LDL: diversity, patterns of recognition, and pathophysiology. Antioxid Redox Signal 2010; 13:39-75. [PMID: 19888833 PMCID: PMC2877120 DOI: 10.1089/ars.2009.2733] [Citation(s) in RCA: 311] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2009] [Revised: 10/09/2009] [Accepted: 11/02/2009] [Indexed: 02/06/2023]
Abstract
Oxidative modification of LDL is known to elicit an array of pro-atherogenic responses, but it is generally underappreciated that oxidized LDL (OxLDL) exists in multiple forms, characterized by different degrees of oxidation and different mixtures of bioactive components. The variable effects of OxLDL reported in the literature can be attributed in large part to the heterogeneous nature of the preparations employed. In this review, we first describe the various subclasses and molecular composition of OxLDL, including the variety of minimally modified LDL preparations. We then describe multiple receptors that recognize various species of OxLDL and discuss the mechanisms responsible for the recognition by specific receptors. Furthermore, we discuss the contentious issues such as the nature of OxLDL in vivo and the physiological oxidizing agents, whether oxidation of LDL is a prerequisite for atherogenesis, whether OxLDL is the major source of lipids in foam cells, whether in some cases it actually induces cholesterol depletion, and finally the Janus-like nature of OxLDL in having both pro- and anti-inflammatory effects. Lastly, we extend our review to discuss the role of LDL oxidation in diseases other than atherosclerosis, including diabetes mellitus, and several autoimmune diseases, such as lupus erythematosus, anti-phospholipid syndrome, and rheumatoid arthritis.
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Affiliation(s)
- Irena Levitan
- Section of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
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Becker C, Riedmaier I, Reiter M, Tichopad A, Pfaffl MW, Meyer HH. Effect of trenbolone acetate plus estradiol on transcriptional regulation of metabolism pathways in bovine liver. Horm Mol Biol Clin Investig 2010; 2:257-65. [DOI: 10.1515/hmbci.2010.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Accepted: 04/26/2010] [Indexed: 11/15/2022]
Abstract
AbstractThe use of anabolic steroids is forbidden for food producing animals in the EU. Owing to the advantages of anabolics for production profitability, illegal application is appealing. Anabolics are known to influence gene expression of several tissues. We focused on the liver because of its important role in nutrient and hormone metabolism. The aim of the present study was to find differentially regulated metabolic pathways, which might be used as treatment biomarkers.A total of 18 Nguni heifers were allocated equally to a control group and a treatment group and were implanted with Revalor H. Expression of 34 target genes was measured using reverse transcriptase quantitative polymerase chain reaction (RT-qPCR).Upregulation of androgen receptor and insulin-like growth factor 1 (IGF-1) and downregulation of IGF-2, insulin-like growth factor binding protein 2, steroid hormone binding globulin, insulin receptor α, insulin receptor β, tyrosine aminotransferase, 17β-hydroxy steroid dehydrogenase 2,3-hydroxy-methylglutaryl-coenzym-A-synthase, cathepsin B, hepatocyte growth factor, steroidogenic acute regulatory protein, apolipoprotein 2 and tumor necrosis factor α was demonstrated.Several biochemical pathways showed different regulations on mRNA level under the influence of trenbolone acetate plus estradiol. The inhibition of nutrient metabolism and protein breakdown seems to support growth processes. IGF-1 plays an important role in growth and development and thus the upregulation of IGF-1 could be responsible for the stimulation of growth in treated animals. The upregulation of IGF-1 could also be revealed as a possible risk factor for the generation of artherosclerotic plaques, which are known as long-term side effects following the use of anabolic steroids. Principal components analysis of RT-qPCR results showed that both groups arrange together and can be clearly separated. Therefore, these might be used as possible biomarkers in bovine liver.
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Lawrence DW, King SB, Frazier WA, Koenig JM. Decreased CD47 expression during spontaneous apoptosis targets neutrophils for phagocytosis by monocyte-derived macrophages. Early Hum Dev 2009; 85:659-63. [PMID: 19815354 PMCID: PMC2800099 DOI: 10.1016/j.earlhumdev.2009.09.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Revised: 08/27/2009] [Accepted: 09/08/2009] [Indexed: 12/22/2022]
Abstract
BACKGROUND Neutrophils (PMN) are the primary leukocyte responders during acute inflammation. After migrating into the tissues, PMN undergo programmed cell death (apoptosis) and are subsequently removed via phagocytosis by resident macrophages during the resolution phase. Efficient phagocytosis of apoptotic neutrophils is necessary for successful resolution. CD47 plays a critical role in mediating the phagocytic response, although its role in the phagocytosis of apoptotic PMN is incompletely understood. AIMS In the present study we tested the hypotheses that CD47 modulates the targeting of apoptotic PMN for phagocytosis, and that this process is altered in neonatal PMN. STUDY DESIGN Adult and neonatal PMN were examined for their expression of CD47. To investigate CD47-mediated functions, apoptotic adult and neonatal PMN were co-cultured with monocyte-derived macrophages (MDM) and the phagocytic index was determined using a flow cytometry-based assay. RESULTS We observed lower basal surface CD47 levels on neonatal vs. adult PMN. In both groups, spontaneous apoptosis led to decreased surface and total cellular CD47 expression. Adult and neonatal MDM ingested apoptotic neonatal target PMN more avidly than apoptotic adult target PMN. Masking of surface CD47 on PMN with a monoclonal antibody enhanced MDM phagocytic activity. CONCLUSIONS Our results suggest that age-dependent expression of CD47 on PMN may account for differences in their ingestion by macrophages and in the resolution of inflammation.
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Affiliation(s)
- Donald W. Lawrence
- Department of Pediatrics, Division of Neonatology, Saint Louis University School of Medicine, Saint Louis, MO 63104
| | | | - William A. Frazier
- Department of Biochemistry and Molecular Biophysics, Washington University, Saint Louis, MO 63110
| | - Joyce M. Koenig
- Department of Pediatrics, Division of Neonatology, Saint Louis University School of Medicine, Saint Louis, MO 63104, Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, MO 63104,CORRESPONDENCE: Joyce M. Koenig, MD, Department of Pediatrics, Edward A. Doisy Research Center, Saint Louis University School of Medicine, 1100 South Grand Blvd., St. Louis, MO 63104 Phone: (314) 977-9291 Fax: (314) 977-9105
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