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Reeves H, Grandjean Lapierre S, Razafindrina K, Andriamiadanarivo A, Rakotosamimanana N, Razafindranaivo T, Seimon T, Blalock B, Bello-Bravo J, Pittendrigh B, McKinney J, Small PM, Knoblauch AM, Fair E. Evaluating the use of educational videos to support the tuberculosis care cascade in remote Madagascar. Int J Tuberc Lung Dis 2021; 24:28-35. [PMID: 32005304 DOI: 10.5588/ijtld.19.0161] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
SETTING: Access to information about tuberculosis (TB) is vital to ensure timely diagnosis, treatment, and control among vulnerable communities. Improved approaches for distributing health education materials to remote populations are needed.OBJECTIVE: To evaluate the impact of two comprehensive video training curricula in improving patient, community member, and community health worker knowledge of TB in a remote area of Madagascar.DESIGN: A pre-test/post-test design was used to measure knowledge acquisition. Educational videos were short, culturally appropriate films presented at critical moments in the TB cascade of care.RESULTS: Of the total 146 participants, 86 (58.9%) improved their score on the post-test, 50 (34.2%) obtained the same score, and 10 (6.8%) received a worse score. A statistically significant difference was observed between the pre- and post-test scores, wherein scores increased by a median of 10.0% (interquartile range 0.0-20.0) after viewing the videos (P < 0.001). There was a significant difference between the number of correct answers on the pre-test and the number of correct answers on the post-test (P < 0.001).CONCLUSION: Educational videos were found to significantly improve TB knowledge among a low-literacy, remote population in Madagascar. Our findings suggest educational videos could be a powerful, low-cost, and sustainable tool to improve access to TB education materials globally.
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Affiliation(s)
- H Reeves
- Institute for Global Health Sciences, University of California, San Francisco, San Francisco, CA
| | - S Grandjean Lapierre
- Global Health Institute, Stony Brook University, New York, NY, USA, Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, QC, Canada
| | - K Razafindrina
- Global Health Institute, Stony Brook University, New York, NY, USA, Centre ValBio, Ifanadiana
| | - A Andriamiadanarivo
- Global Health Institute, Stony Brook University, New York, NY, USA, Centre ValBio, Ifanadiana
| | | | - T Razafindranaivo
- Madagascar National Tuberculosis Control Program, Antananarivo, Madagascar
| | - T Seimon
- In Tune for Life, London, UK and Geneva, Switzerland
| | - B Blalock
- Michigan State University, East Lansing, MI, USA
| | | | | | - J McKinney
- Global Health Institute, Stony Brook University, New York, NY, USA, Centre ValBio, Ifanadiana
| | - P M Small
- Global Health Institute, Stony Brook University, New York, NY, USA
| | - A M Knoblauch
- Global Health Institute, Stony Brook University, New York, NY, USA, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - E Fair
- Institute for Global Health Sciences, University of California, San Francisco, San Francisco, CA, Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
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2
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Gilbert M, Sulikhan N, Uphyrkina O, Goncharuk M, Kerley L, Castro EH, Reeve R, Seimon T, McAloose D, Seryodkin IV, Naidenko SV, Davis CA, Wilkie GS, Vattipally SB, Adamson WE, Hinds C, Thomson EC, Willett BJ, Hosie MJ, Logan N, McDonald M, Ossiboff RJ, Shevtsova EI, Belyakin S, Yurlova AA, Osofsky SA, Miquelle DG, Matthews L, Cleaveland S. Distemper, extinction, and vaccination of the Amur tiger. Proc Natl Acad Sci U S A 2020; 117:31954-31962. [PMID: 33229566 PMCID: PMC7749280 DOI: 10.1073/pnas.2000153117] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Canine distemper virus (CDV) has recently emerged as an extinction threat for the endangered Amur tiger (Panthera tigris altaica). CDV is vaccine-preventable, and control strategies could require vaccination of domestic dogs and/or wildlife populations. However, vaccination of endangered wildlife remains controversial, which has led to a focus on interventions in domestic dogs, often assumed to be the source of infection. Effective decision making requires an understanding of the true reservoir dynamics, which poses substantial challenges in remote areas with diverse host communities. We carried out serological, demographic, and phylogenetic studies of dog and wildlife populations in the Russian Far East to show that a number of wildlife species are more important than dogs, both in maintaining CDV and as sources of infection for tigers. Critically, therefore, because CDV circulates among multiple wildlife sources, dog vaccination alone would not be effective at protecting tigers. We show, however, that low-coverage vaccination of tigers themselves is feasible and would produce substantive reductions in extinction risks. Vaccination of endangered wildlife provides a valuable component of conservation strategies for endangered species.
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Affiliation(s)
- Martin Gilbert
- Cornell Wildlife Health Center, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853;
- Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, United Kingdom
- Wildlife Conservation Society, Bronx, NY 10460
| | - Nadezhda Sulikhan
- Federal Scientific Center of the East Asia Terrestrial Biodiversity, Far Eastern Branch of Russian Academy of Sciences, Vladivostok 690022, Russia
- Land of the Leopard National Park, Vladivostok 690068, Russia
| | - Olga Uphyrkina
- Federal Scientific Center of the East Asia Terrestrial Biodiversity, Far Eastern Branch of Russian Academy of Sciences, Vladivostok 690022, Russia
| | - Mikhail Goncharuk
- Zoological Society of London, London NW1 4RY, United Kingdom
- Primorskaya State Agricultural Academy, Ussuriisk 692510, Russia
| | - Linda Kerley
- Zoological Society of London, London NW1 4RY, United Kingdom
- United Administration of Lazovsky Zapovednik and Zov Tigra National Park, Lazo 692890, Russia
- Autonomous Noncommercial Organization "Amur," Lazo 692890, Russia
| | - Enrique Hernandez Castro
- Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Richard Reeve
- Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | | | | | - Ivan V Seryodkin
- Pacific Geographical Institute, Far Eastern Branch of the Russian Academy of Sciences, Vladivostok 690041, Russia
- Far Eastern Federal University, Vladivostok 690091 Russia
| | - Sergey V Naidenko
- A. N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow 119071, Russia
| | - Christopher A Davis
- Medical Research Council-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, United Kingdom
| | - Gavin S Wilkie
- Medical Research Council-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, United Kingdom
| | - Sreenu B Vattipally
- Medical Research Council-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, United Kingdom
| | - Walt E Adamson
- Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, United Kingdom
- Medical Research Council-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, United Kingdom
| | - Chris Hinds
- Medical Research Council-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, United Kingdom
| | - Emma C Thomson
- Medical Research Council-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, United Kingdom
| | - Brian J Willett
- Medical Research Council-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, United Kingdom
| | - Margaret J Hosie
- Medical Research Council-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, United Kingdom
| | - Nicola Logan
- Medical Research Council-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, United Kingdom
| | - Michael McDonald
- Medical Research Council-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, United Kingdom
| | - Robert J Ossiboff
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610
| | | | - Stepan Belyakin
- Institute of Molecular and Cellular Biology, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Anna A Yurlova
- Institute of Molecular and Cellular Biology, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Steven A Osofsky
- Cornell Wildlife Health Center, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853
| | | | - Louise Matthews
- Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Sarah Cleaveland
- Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, United Kingdom
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McAloose D, Rago MV, Di Martino M, Chirife A, Olson SH, Beltramino L, Pozzi LM, Musmeci L, La Sala L, Mohamed N, Sala JE, Bandieri L, Andrejuk J, Tomaszewicz A, Seimon T, Sironi M, Samartino LE, Rowntree V, Uhart MM. Post-mortem findings in southern right whales Eubalaena australis at Península Valdés, Argentina, 2003-2012. Dis Aquat Organ 2016; 119:17-36. [PMID: 27068500 DOI: 10.3354/dao02986] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Between 2003 and 2012, 605 southern right whales (SRW; Eubalaena australis) were found dead along the shores of Península Valdés (PV), Argentina. These deaths included alarmingly high annual losses between 2007 and 2012, a peak number of deaths (116) in 2012, and a significant number of deaths across years in calves-of-the-year (544 of 605 [89.9%]; average = 60.4 yr(-1)). Post-mortem examination and pathogen testing were performed on 212 whales; 208 (98.1%) were calves-of-the-year and 48.0% of these were newborns or neonates. A known or probable cause of death was established in only a small number (6.6%) of cases. These included ship strike in a juvenile and blunt trauma or lacerations (n = 5), pneumonia (n = 4), myocarditis (n = 2), meningitis (n = 1), or myocarditis and meningitis (n = 1) in calves. Ante-mortem gull parasitism was the most common gross finding. It was associated with systemic disease in a single 1-2 mo old calf. Immunohistochemical labeling for canine distemper virus, Toxoplasma gondii and Brucella spp., and PCR for cetacean morbillivirus (CeMV), influenza A, and apicomplexan protozoa were negative on formalin-fixed, paraffin-embedded lung and brain samples from a subset of whales; PCR for Brucella spp. was positive in a newborn/neonate with pneumonia. Skin samples from whales with gull parasitism were PCR negative for CeMV, poxvirus, and papillomavirus. This is the first long-term study to investigate and summarize notable post-mortem findings in the PV SRW population. Consistent, significant findings within or between years to explain the majority of deaths and those in high-mortality years remain to be identified.
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Affiliation(s)
- Denise McAloose
- Wildlife Conservation Society Zoological Health Program, Bronx, New York 10464, USA
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4
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Anthony SJ, St. Leger JA, Navarrete-Macias I, Nilson E, Sanchez-Leon M, Liang E, Seimon T, Jain K, Karesh W, Daszak P, Briese T, Lipkin WI. Identification of a novel cetacean polyomavirus from a common dolphin (Delphinus delphis) with Tracheobronchitis. PLoS One 2013; 8:e68239. [PMID: 23874559 PMCID: PMC3707911 DOI: 10.1371/journal.pone.0068239] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 05/27/2013] [Indexed: 01/20/2023] Open
Abstract
A female short-beaked common dolphin calf was found stranded in San Diego, California in October 2010, presenting with multifocal ulcerative lesions in the trachea and bronchi. Viral particles suggestive of polyomavirus were detected by EM, and subsequently confirmed by PCR and sequencing. Full genome sequencing (Ion Torrent) revealed a circular dsDNA genome of 5,159 bp that was shown to form a distinct lineage within the genus Polyomavirus based on phylogenetic analysis of the early and late transcriptomes. Viral infection and distribution in laryngeal mucosa was characterised using in-situ hybridisation, and apoptosis observed in the virus-infected region. These results demonstrate that polyomaviruses can be associated with respiratory disease in cetaceans, and expand our knowledge of their diversity and clinical significance in marine mammals.
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Affiliation(s)
- Simon J. Anthony
- Center for Infection and Immunity, Mailman School of Public Health, Columbia University, New York, New York, United States of America
- EcoHealth Alliance, New York, New York, United States of America
- * E-mail: (SJA); (JASL)
| | - Judy A. St. Leger
- Department of Pathology and Research, SeaWorld Parks, San Diego, California, United States of America
- * E-mail: (SJA); (JASL)
| | - Isamara Navarrete-Macias
- Center for Infection and Immunity, Mailman School of Public Health, Columbia University, New York, New York, United States of America
| | - Erica Nilson
- Department of Pathology and Research, SeaWorld Parks, San Diego, California, United States of America
| | - Maria Sanchez-Leon
- Center for Infection and Immunity, Mailman School of Public Health, Columbia University, New York, New York, United States of America
| | - Eliza Liang
- Center for Infection and Immunity, Mailman School of Public Health, Columbia University, New York, New York, United States of America
- EcoHealth Alliance, New York, New York, United States of America
| | - Tracie Seimon
- Center for Infection and Immunity, Mailman School of Public Health, Columbia University, New York, New York, United States of America
- Wildlife Conservation Society, Bronx Zoo, New York, New York, United States of America
| | - Komal Jain
- Center for Infection and Immunity, Mailman School of Public Health, Columbia University, New York, New York, United States of America
| | - William Karesh
- EcoHealth Alliance, New York, New York, United States of America
| | - Peter Daszak
- EcoHealth Alliance, New York, New York, United States of America
| | - Thomas Briese
- Center for Infection and Immunity, Mailman School of Public Health, Columbia University, New York, New York, United States of America
| | - W. Ian Lipkin
- Center for Infection and Immunity, Mailman School of Public Health, Columbia University, New York, New York, United States of America
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5
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Smith KM, Anthony SJ, Switzer WM, Epstein JH, Seimon T, Jia H, Sanchez MD, Huynh TT, Galland GG, Shapiro SE, Sleeman JM, McAloose D, Stuchin M, Amato G, Kolokotronis SO, Lipkin WI, Karesh WB, Daszak P, Marano N. Zoonotic viruses associated with illegally imported wildlife products. PLoS One 2012; 7:e29505. [PMID: 22253731 PMCID: PMC3254615 DOI: 10.1371/journal.pone.0029505] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Accepted: 11/29/2011] [Indexed: 12/14/2022] Open
Abstract
The global trade in wildlife has historically contributed to the emergence and spread of infectious diseases. The United States is the world's largest importer of wildlife and wildlife products, yet minimal pathogen surveillance has precluded assessment of the health risks posed by this practice. This report details the findings of a pilot project to establish surveillance methodology for zoonotic agents in confiscated wildlife products. Initial findings from samples collected at several international airports identified parts originating from nonhuman primate (NHP) and rodent species, including baboon, chimpanzee, mangabey, guenon, green monkey, cane rat and rat. Pathogen screening identified retroviruses (simian foamy virus) and/or herpesviruses (cytomegalovirus and lymphocryptovirus) in the NHP samples. These results are the first demonstration that illegal bushmeat importation into the United States could act as a conduit for pathogen spread, and suggest that implementation of disease surveillance of the wildlife trade will help facilitate prevention of disease emergence.
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Affiliation(s)
- Kristine M Smith
- Wildlife Conservation Society, Bronx, New York, United States of America.
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6
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Shechtman CF, Henneberry A, Seimon T, Tabas I, Sturley SL. The Role of Arv1 in Sterol Metabolism and its Contribution to the Unfolded Protein Response. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.845.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Tracie Seimon
- Departments of Medicine, Cell Biology & Physiology and Cellular Biophysics
| | - Ira Tabas
- Departments of Medicine, Cell Biology & Physiology and Cellular Biophysics
| | - Stephen L Sturley
- Institute of Human Nutrition
- Department of PediatricsColumbia UniversityNew YorkNY
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7
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Abstract
Plaque necrosis in advanced atheromata, which triggers acute atherothrombotic vascular events, is caused by the apoptosis of lesional macrophages coupled with defective phagocytic clearance of the dead cells. The central enabling event in macrophage apoptosis relevant to advanced atherosclerosis is the unfolded protein response (UPR), an endoplasmic reticulum (ER) stress pathway. The UPR effector CHOP (GADD153) amplifies release of ER Ca(2+) stores, which activates a central integrator of apoptosis signaling, calcium/calmodulin-dependent protein kinase II (CaMKII). CaMKII, in turn, leads to activation of pro-apoptotic STAT1, induction of the death receptor Fas, and stimulation of the mitochondria-cytochrome c pathway of apoptosis. While these pathways are necessary for apoptosis, apoptosis occurs only when the cells are also exposed to one or more additional "hits." These hits amplify pro-apoptotic pathways and/or suppress compensatory cell-survival pathways. A second hit relevant to atherosclerosis is activation of pattern recognition receptors (PRRs), such as scavenger and toll-like receptors. In vivo relevance is suggested by the fact that advanced human lesions express markers of UPR activation that correlate closely with the degree of plaque vulnerability and macrophage apoptosis. Moreover, studies with genetically altered mice have shown that ER stress and PRR activation are causative for advanced lesional macrophage apoptosis and plaque necrosis. In summary, a key cellular event in the conversion of benign to vulnerable atherosclerotic plaques is ER stress-induced macrophage apoptosis. Further understanding of the mechanisms and consequences of this event may lead to novel therapies directed at preventing the clinical progression of atheromata.
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Affiliation(s)
- Ira Tabas
- Department of Medicine, Columbia University Medical Center, New York, New York, USA.
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8
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Sun Y, Ishibashi M, Seimon T, Lee M, Sharma SM, Fitzgerald KA, Samokhin AO, Wang Y, Sayers S, Aikawa M, Jerome WG, Ostrowski MC, Bromme D, Libby P, Tabas IA, Welch CL, Tall AR. Free cholesterol accumulation in macrophage membranes activates Toll-like receptors and p38 mitogen-activated protein kinase and induces cathepsin K. Circ Res 2009; 104:455-65. [PMID: 19122179 DOI: 10.1161/circresaha.108.182568] [Citation(s) in RCA: 126] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The molecular events linking lipid accumulation in atherosclerotic plaques to complications such as aneurysm formation and plaque disruption are poorly understood. BALB/c-Apoe(-/-) mice bearing a null mutation in the Npc1 gene display prominent medial erosion and atherothrombosis, whereas their macrophages accumulate free cholesterol in late endosomes and show increased cathepsin K (Ctsk) expression. We now show increased cathepsin K immunostaining and increased cysteinyl proteinase activity using near infrared fluorescence imaging over proximal aortas of Apoe(-/-), Npc1(-/-) mice. In mechanistic studies, cholesterol loading of macrophage plasma membranes (cyclodextrin-cholesterol) or endosomal system (AcLDL+U18666A or Npc1 null mutation) activated Toll-like receptor (TLR) signaling, leading to sustained phosphorylation of p38 mitogen-activated protein kinase and induction of p38 targets, including Ctsk, S100a8, Mmp8, and Mmp14. Studies in macrophages from knockout mice showed major roles for TLR4, following plasma membrane cholesterol loading, and for TLR3, after late endosomal loading. TLR signaling via p38 led to phosphorylation and activation of the transcription factor Microphthalmia transcription factor, acting at E-box elements in the Ctsk promoter. These studies suggest that free cholesterol enrichment of either plasma or endosomal membranes in macrophages leads to activation of signaling via various TLRs, prolonged p38 mitogen-activated protein kinase activation, and induction of Mmps, Ctsk, and S100a8, potentially contributing to plaque complications.
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Affiliation(s)
- Yu Sun
- Department of Medicine, Columbia University, New York, NY 10032, USA.
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9
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Abstract
Macrophage apoptosis is an important feature of atherosclerotic plaque development. Research directed at understanding the functional consequences of macrophage death in atherosclerosis has revealed opposing roles for apoptosis in atherosclerotic plaque progression. In early lesions, macrophage apoptosis limits lesion cellularity and suppresses plaque progression. In advanced lesions, macrophages apoptosis promotes the development of the necrotic core, a key factor in rendering plaques vulnerable to disruption and in acute lumenal thrombosis. The first section of this review will examine the role of phagocytic clearance of apoptotic macrophages, a process known as efferocytosis, in the dichotomous roles of macrophage apoptosis in early vs. advanced lesions. The second section will focus on the molecular and cellular mechanisms that are thought to govern macrophage death during atherosclerosis. Of particular interest is the complex and coordinated role that the endoplasmic reticulum (ER) stress pathway and pattern recognition receptors (PRRs) may play in triggering macrophage apoptosis.
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Affiliation(s)
- Tracie Seimon
- Department of Medicine, Columbia University, New York, NY 10032, USA
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Iqbal J, Dai K, Seimon T, Jungreis R, Oyadomari M, Kuriakose G, Ron D, Tabas I, Hussain MM. IRE1beta inhibits chylomicron production by selectively degrading MTP mRNA. Cell Metab 2008; 7:445-55. [PMID: 18460335 PMCID: PMC2435513 DOI: 10.1016/j.cmet.2008.03.005] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2007] [Revised: 12/30/2007] [Accepted: 03/10/2008] [Indexed: 01/22/2023]
Abstract
Microsomal triglyceride transfer protein (MTP) is needed to assemble chylomicrons in the endoplasmic reticulum (ER) of enterocytes. We explored the role of an ER stress protein, inositol-requiring enzyme 1beta (IRE1beta), in regulating this process. High-cholesterol and high-fat diets decreased intestinal IRE1beta mRNA in wild-type mice. Ire1b(-/-) mice fed high-cholesterol and high-fat diets developed more pronounced hyperlipidemia because these mice secreted more chylomicrons and expressed more intestinal MTP, though not hepatic MTP, than wild-type mice did. Chylomicron secretion and MTP expression also were increased in primary enterocytes isolated from cholesterol-fed Ire1b(-/-) mice. There was no correlation between ER stress and MTP expression. Instead, cell culture studies revealed that IRE1beta, but not its ubiquitous homolog IRE1alpha, decreased MTP mRNA through increased posttranscriptional degradation. Conversely, knockdown of IRE1beta enhanced MTP expression. These studies show that IRE1beta plays a role in regulating MTP and in chylomicron production.
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Affiliation(s)
- Jahangir Iqbal
- Department of Anatomy and Cell Biology and Department of Pediatrics, The State University of New York Downstate Medical Center, Brooklyn, NY 11203, USA
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11
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Affiliation(s)
- T Seimon
- Sri Lanka UNICEF Child Mental Health Programme.
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