2089 Detecting inflammation in atherosclerosis using protein cage nanoparticles as cellular imaging...
3
BioMed Central Page 1 of 3 (page number not for citation purposes) Journal of Cardiovascular Magnetic Resonance Open Access Meeting abstract 2089 Detecting inflammation in atherosclerosis using protein cage nanoparticles as cellular imaging agents Masahiro Terashima* 1 , Masaki Uchida 2 , Hisanori Kosuge 1 , Shay Keren 1 , Philip S Tsao 1 , Mark J Young 2 , Trevor Douglas 2 and Michael V McConnell 1 Address: 1 Stanford University, Stanford, CA, USA and 2 Montana State University, Bozeman, MT, USA * Corresponding author Introduction Macrophages are important imaging targets for identify- ing and monitoring high-risk atherosclerotic plaque. Human heavy chain ferritin (HFn) is a promising nanos- cale protein cage platform for cellular and molecular imaging, demonstrating substantial in vitro uptake by macrophages. Purpose To evaluate the in vivo uptake and distribution of MRI and fluorescent HFn nanoparticles in mouse atherosclero- sis. Methods A macrophage-rich carotid lesion in FVB mice (n = 12) was induced as follows: high fat diet for 4 weeks then dia- betes induction by 5 daily intraperitoneal injections of streptozotocin. Two weeks later, we performed carotid ligation of the left common carotid artery. In the first group of mice (n = 5), an MRI form of HFn containing iron oxide (HFn-3000Fe) was injected via tail vein (25 mgFe/kg) 2 weeks after carotid ligation. Mice were sacri- ficed 48 hours after injection and HFn-Fe uptake was assessed histologically by Perl's iron staining. In the sec- ond group of mice (4 diseased and 3 sham), HFn was labeled with the near-infrared (NIR) fluorophore Cy5.5 (HFn-Cy5.5: 4.6 Cy5.5 dye/cage) and injected via tail vein (8 nmol of Cy5.5) 2 weeks after carotid ligation. Mice were imaged serially by in vivo NIR imaging up to 48 hours. At 48 hours, both carotid arteries were exposed for in situ NIR imaging, and then removed for ex vivo NIR imaging. All mice were imaged under 2% isoflurane anesthesia using the MaestroTM in-vivo imaging system (CRI, Woburn, MA). After the NIR imaging, both carotid arteries were removed and cut into 2 mm sections for con- focal fluorescence microscopy to detect HFn-Cy5.5 colo- calized with macrophages. Results HFn iron oxide nanoparticles (HFn-Fe) were taken up by macrophages in the ligated left carotid artery at 48 hours, as demonstrated by histology (Fig 1A). No HFn-Fe uptake was seen in the control right carotid arteries. In vivo fluo- rescence imaging detected HFn-Cy5.5 at 10 min after intravenous injection, with the predominant signal in the liver, bladder, and neck lymph nodes. In situ (Fig 2A), the average fluorescence signal was significantly higher in the ligated left carotid arteries at 48 hours (Left: 0.27 ± 0.05, Right: 0.13 ± 0.04, p = 0.04). No significant signal was seen in sham-operated mice (Left: 0.16 ± 0.06, Right: 0.12 ± 0.01, p = 0.3). The enhanced signal in the ligated left carotid arteries was further confirmed by ex vivo fluores- cence imaging (Left: 429 ± 23, Right: 10 ± 10, p = 0.0001), with minimum signal detected in the sham-operated mice (Left: 12 ± 12, Right: 0 ± 0, p = 0.4) (Fig 2B). On confocal fluorescence microscopy, HFn-Cy5.5 nanoparticles colo- calized with macrophages in the neointima of the ligated carotid artery (Figure 1B). from 11 th Annual SCMR Scientific Sessions Los Angeles, CA, USA. 1–3 February 2008 Published: 22 October 2008 Journal of Cardiovascular Magnetic Resonance 2008, 10(Suppl 1):A358 doi:10.1186/1532-429X-10-S1-A358 <supplement> <title> <p>Abstracts of the 11<sup>th </sup>Annual SCMR Scientific Sessions - 2008</p> </title> <note>Meeting abstracts – A single PDF containing all abstracts in this Supplement is available <a href="http://www.biomedcentral.com/content/files/pdf/1532-429X-10-s1-full.pdf">here</a>.</note> <url>http://www.biomedcentral.com/content/pdf/1532-429X-10-S1-info.pdf</url> </supplement> This abstract is available from: http://jcmr-online.com/content/10/S1/A358 © 2008 Terashima et al; licensee BioMed Central Ltd.
-
Upload
masahiro-terashima -
Category
Documents
-
view
212 -
download
0
Transcript of 2089 Detecting inflammation in atherosclerosis using protein cage nanoparticles as cellular imaging...
BioMed Central
Journal of Cardiovascular Magnetic Resonance
ss
Open AcceMeeting abstract2089 Detecting inflammation in atherosclerosis using protein cage nanoparticles as cellular imaging agentsMasahiro Terashima*1, Masaki Uchida2, Hisanori Kosuge1, Shay Keren1, Philip S Tsao1, Mark J Young2, Trevor Douglas2 and Michael V McConnell1Address: 1Stanford University, Stanford, CA, USA and 2Montana State University, Bozeman, MT, USA
* Corresponding author
IntroductionMacrophages are important imaging targets for identify-ing and monitoring high-risk atherosclerotic plaque.Human heavy chain ferritin (HFn) is a promising nanos-cale protein cage platform for cellular and molecularimaging, demonstrating substantial in vitro uptake bymacrophages.
PurposeTo evaluate the in vivo uptake and distribution of MRIand fluorescent HFn nanoparticles in mouse atherosclero-sis.
MethodsA macrophage-rich carotid lesion in FVB mice (n = 12)was induced as follows: high fat diet for 4 weeks then dia-betes induction by 5 daily intraperitoneal injections ofstreptozotocin. Two weeks later, we performed carotidligation of the left common carotid artery. In the firstgroup of mice (n = 5), an MRI form of HFn containingiron oxide (HFn-3000Fe) was injected via tail vein (25mgFe/kg) 2 weeks after carotid ligation. Mice were sacri-ficed 48 hours after injection and HFn-Fe uptake wasassessed histologically by Perl's iron staining. In the sec-ond group of mice (4 diseased and 3 sham), HFn waslabeled with the near-infrared (NIR) fluorophore Cy5.5(HFn-Cy5.5: 4.6 Cy5.5 dye/cage) and injected via tail vein(8 nmol of Cy5.5) 2 weeks after carotid ligation. Micewere imaged serially by in vivo NIR imaging up to 48hours. At 48 hours, both carotid arteries were exposed for
in situ NIR imaging, and then removed for ex vivo NIRimaging. All mice were imaged under 2% isofluraneanesthesia using the MaestroTM in-vivo imaging system(CRI, Woburn, MA). After the NIR imaging, both carotidarteries were removed and cut into 2 mm sections for con-focal fluorescence microscopy to detect HFn-Cy5.5 colo-calized with macrophages.
ResultsHFn iron oxide nanoparticles (HFn-Fe) were taken up bymacrophages in the ligated left carotid artery at 48 hours,as demonstrated by histology (Fig 1A). No HFn-Fe uptakewas seen in the control right carotid arteries. In vivo fluo-rescence imaging detected HFn-Cy5.5 at 10 min afterintravenous injection, with the predominant signal in theliver, bladder, and neck lymph nodes. In situ (Fig 2A), theaverage fluorescence signal was significantly higher in theligated left carotid arteries at 48 hours (Left: 0.27 ± 0.05,Right: 0.13 ± 0.04, p = 0.04). No significant signal wasseen in sham-operated mice (Left: 0.16 ± 0.06, Right: 0.12± 0.01, p = 0.3). The enhanced signal in the ligated leftcarotid arteries was further confirmed by ex vivo fluores-cence imaging (Left: 429 ± 23, Right: 10 ± 10, p = 0.0001),with minimum signal detected in the sham-operated mice(Left: 12 ± 12, Right: 0 ± 0, p = 0.4) (Fig 2B). On confocalfluorescence microscopy, HFn-Cy5.5 nanoparticles colo-calized with macrophages in the neointima of the ligatedcarotid artery (Figure 1B).
from 11th Annual SCMR Scientific SessionsLos Angeles, CA, USA. 1–3 February 2008
Published: 22 October 2008
Journal of Cardiovascular Magnetic Resonance 2008, 10(Suppl 1):A358 doi:10.1186/1532-429X-10-S1-A358
<supplement> <title> <p>Abstracts of the 11<sup>th </sup>Annual SCMR Scientific Sessions - 2008</p> </title> <note>Meeting abstracts – A single PDF containing all abstracts in this Supplement is available <a href="http://www.biomedcentral.com/content/files/pdf/1532-429X-10-s1-full.pdf">here</a>.</note> <url>http://www.biomedcentral.com/content/pdf/1532-429X-10-S1-info.pdf</url> </supplement>
This abstract is available from: http://jcmr-online.com/content/10/S1/A358
© 2008 Terashima et al; licensee BioMed Central Ltd.
Page 1 of 3(page number not for citation purposes)
Journal of Cardiovascular Magnetic Resonance 2008, 10(Suppl 1):A358 http://jcmr-online.com/content/10/S1/A358
ConclusionHuman ferritin protein cages labeled with iron oxide orfluorophore localize to macrophages in the atheroscle-rotic lesions in vivo. These initial results encourage furtherinvestigation into the use of protein cage architectures asa novel platform for MR or NIR contrast agents for detect-ing macrophage infiltration within atheroscleroticplaques.
Figure 1
Page 2 of 3(page number not for citation purposes)
Publish with BioMed Central and every scientist can read your work free of charge
"BioMed Central will be the most significant development for disseminating the results of biomedical research in our lifetime."
Sir Paul Nurse, Cancer Research UK
Your research papers will be:
available free of charge to the entire biomedical community
peer reviewed and published immediately upon acceptance
cited in PubMed and archived on PubMed Central
yours — you keep the copyright
Submit your manuscript here:http://www.biomedcentral.com/info/publishing_adv.asp
BioMedcentral
Journal of Cardiovascular Magnetic Resonance 2008, 10(Suppl 1):A358 http://jcmr-online.com/content/10/S1/A358
Page 3 of 3(page number not for citation purposes)
Figure 2
