Monocyte-directed RNAi targeting CCR2 improves infarct healing in atherosclerosis-prone mice
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Author
Majmudar, Maulik D.
Keliher, Edmund J.
Heidt, Timo
Leuschner, Florian
Truelove, Jessica
Sena, Brena F.
Gorbatov, Rostic
Iwamoto, Yoshiko
Dutta, Partha
Wojtkiewicz, Gregory
Courties, Gabriel
Sebas, Matt
Borodovsky, Anna
Fitzgerald, Kevin
Nolte, Marc W.
Dickneite, Gerhard
Chen, John W.
Anderson, Daniel G.
Swirski, Filip K.
Weissleder, Ralph
Nahrendorf, Matthias
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https://doi.org/10.1161/CIRCULATIONAHA.112.000116Metadata
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Majmudar, Maulik D., Edmund J. Keliher, Timo Heidt, Florian Leuschner, Jessica Truelove, Brena F. Sena, Rostic Gorbatov, et al. 2013. “Monocyte-Directed RNAi Targeting CCR2 Improves Infarct Healing in Atherosclerosis-Prone Mice.” Circulation 127 (20): 2038–46. https://doi.org/10.1161/circulationaha.112.000116.Abstract
Background-Exaggerated and prolonged inflammation after myocardial infarction (MI) accelerates left ventricular remodeling. Inflammatory pathways may present a therapeutic target to prevent post-MI heart failure. However, the appropriate magnitude and timing of interventions are largely unknown, in part because noninvasive monitoring tools are lacking. Here, we used nanoparticle-facilitated silencing of CCR2, the chemokine receptor that governs inflammatory Ly-6C(high) monocyte subset traffic, to reduce infarct inflammation in apolipoprotein E-deficient (apoE(-/-)) mice after MI. We used dual-target positron emission tomography/magnetic resonance imaging of transglutaminase factor XIII (FXIII) and myeloperoxidase (MPO) activity to monitor how monocyte subset-targeted RNAi altered infarct inflammation and healing. Methods: and Results-Flow cytometry, gene expression analysis, and histology revealed reduced monocyte numbers and enhanced resolution of inflammation in infarcted hearts of apoE(-/-) mice that were treated with nanoparticle-encapsulated siRNA. To follow extracellular matrix cross-linking noninvasively, we developed a fluorine-18-labeled positron emission tomography agent (F-18-FXIII). Recruitment of MPO-rich inflammatory leukocytes was imaged with a molecular magnetic resonance imaging sensor of MPO activity (MPO-Gd). Positron emission tomography/magnetic resonance imaging detected anti-inflammatory effects of intravenous nanoparticle-facilitated siRNA therapy (75% decrease of MPO-Gd signal; P<0.05), whereas F-18-FXIII positron emission tomography reflected unimpeded matrix cross-linking in the infarct. Silencing of CCR2 during the first week after MI improved ejection fraction on day 21 after MI from 29% to 35% (P<0.05). Conclusion- CCR2-targeted RNAi reduced recruitment of Ly-6C(high) monocytes, attenuated infarct inflammation, and curbed post-MI left ventricular remodeling.Terms of Use
This article is made available under the terms and conditions applicable to Other Posted Material, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#LAACitable link to this page
http://nrs.harvard.edu/urn-3:HUL.InstRepos:41384203
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