Research ArticleCardiovascular Disease

Targeted nanoparticles containing the proresolving peptide Ac2-26 protect against advanced atherosclerosis in hypercholesterolemic mice

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Science Translational Medicine  18 Feb 2015:
Vol. 7, Issue 275, pp. 275ra20
DOI: 10.1126/scitranslmed.aaa1065
  • Fig. 1. Col IV Ac2-26 NPs home to atherosclerotic lesions.

    Ldlr−/− mice were fed a Western diet for 12 weeks and then injected intravenously with Alexa 647–labeled Ac2-26 NPs or Col IV–Ac2-26 NPs. The diet was continued, and aortic root sections were analyzed by fluorescence microscopy 5 days later. (A) Images of 4′,6-diamidino-2-phenylindole (DAPI)–stained aortic root sections showing NPs (red) and nuclei (blue). The lesions in each image are outlined. To the right of each main image is a zoomed-in image of the subendothelial region depicted by the white box. Scale bar, 100 μm. (B) Sections of aortic root, spleen, and liver (six sections per mouse) were quantified for mean Alexa 647 fluorescence intensity (MFI) using image processing. Data are means ± SEM (n = 3 separate mice). *P < 0.05 versus Ac2-26, Student’s t test.

  • Fig. 2. Col IV–Ac2-26 NPs increase subendothelial collagen in Ldlr−/− mice with established atherosclerosis.

    Ldlr−/− mice were fed the Western diet for 12 weeks and then injected intravenously with vehicle, free Ac2-26, or Col IV NPs containing scrambled peptide (Scrm) or Ac2-26 once per week for 5 weeks, with the mice remaining on the diet. (A) Aortic root sections from the indicated groups of mice were stained with picrosirius red. The pair of images from the 17-week Col IV–Scrm NP and Col IV–Ac2-26 NP cohorts (left) shows examples of measuring lines used to measure cap thickness. The microscopic images were quantified by image processing for fibrous cap thickness/lesion area ratio, expressed as arbitrary ratio units (AU) (right). Data are individual mice, with means shown as horizontal lines (n = 8 to 10 separate mice, two sections per mouse). Scale bar, 100 μm. (B) Collagenase activity quantified in aortic root sections using fluorescence microscopy and image processing. Data are individual mice, with means shown as horizontal lines (n = 8 to 10 separate mice, two sections per mouse). (C) RNA from the aortic root lesions of five mice per treatment group was obtained by laser capture microdissection (LCM), pooled, and quantified by reverse transcription quantitative polymerase chain reaction (RT-qPCR) for Col3a1 mRNA, with normalization to lesional Actb mRNA. Data are means ± SEM. ***P < 0.001 versus all other groups, one-way analysis of variance (ANOVA) with post hoc Tukey analysis.

  • Fig. 3. Col IV–Ac2-26 NPs suppress lesional superoxide and increase lesional Il10 mRNA in Ldlr−/− mice with established atherosclerosis.

    (A to C) Ldlr−/− mice were fed the Western diet for 12 weeks and then injected intravenously with vehicle, free Ac2-26, or Col IV NPs containing scrambled peptide (Scrm) or Ac2-26 once per week for 5 weeks, with the mice remaining on the diet. (A) Superoxide (DHE), macrophages (Mac3), and DAPI nuclear staining were assessed by fluorescence microscopy, and the percent of DHE+Mac3+ double-labeled intimal cells per total DAPI+ intimal cells was quantified using image processing. Nuclear (B) and nonnuclear (C) 8-OHdG staining in Mac3+ cells as a percentage of total lesional Mac3+ cell was quantified by fluorescence microscopy and image processing. Data are individual mice, with means shown as horizontal lines (n = 8 to 10, two sections per mouse). (D) Lesional Il10 mRNA was quantified by RT-qPCR, with normalization to lesional Actb mRNA. Data are means ± SEM (n = 8 to 10 separate mice, two sections per mouse). **P < 0.01, ***P < 0.001 versus all other groups, one-way ANOVA with post hoc Tukey analysis.

  • Fig. 4. Col IV–Ac2-26 NPs exert atheroprotective actions in myeloid-derived cells in an FPR2/ALX-dependent manner.

    Ldlr−/− mice were transplanted with bone marrow from WT or Fpr2−/− bone marrow. (A) Aortic root sections were stained with hematoxylin and eosin (H&E) (left), and cap thickness was quantified (right). Scale bar, 100 μm. (B) Collagenase activity was quantified in aortic root sections using fluorescence microscopy and image processing. (C) Superoxide (DHE) was assessed by fluorescence microscopy. Data are for individual mice, with means shown as horizontal lines (n = 5 separate mice, two sections per mouse). **P < 0.01 versus all other groups, one-way ANOVA with post hoc Tukey analysis.

  • Fig. 5. Col IV–Ac2-26 NPs decrease lesion area, necrotic area, and oxidative stress in brachiocephalic arterial plaques.

    Ldlr−/− mice were fed the Western diet for 12 weeks and then injected intravenously with Col IV NPs containing scrambled peptide (Scrm) or Ac2-26 once per week for 5 weeks, with the mice remaining on the diet. (A and B) Representative whole-mount (A) or cross-sectioned specimens (B) of BCA lesions were visualized en bloc or in cross section. Scale bar, 100 μm. (C to F) Cross sections were quantified for lesion area (C), necrotic area (D), ICAM immunostaining (E), and superoxide (DHE fluorescence) (F). Data are for individual mice, with means shown as horizontal lines (n = 8 to 10 separate mice, two sections per mouse). *P < 0.05, **P < 0.01, ***P < 0.001, Student’s t test.

Supplementary Materials

  • www.sciencetranslationalmedicine.org/cgi/content/full/7/275/275ra20/DC1

    Fig. S1. Engineered NPs with Col IV targeting peptide.

    Fig. S2. Metabolic parameters of the mice were unaffected by treatment with Col IV–Ac2-26 NPs or controls.

    Fig. S3. Col IV–Ac2-26 NP treatment does not affect collagen content, superoxide, or mRNA of Il10 or Acta2 in the liver or spleen.

    Fig. S4. Col IV–Ac2-26 NP treatment does not affect aortic root lesion area or the numbers of lesional macrophages and SMCs.

    Fig. S5. Ac2-26 decreases 7KC-induced ROS in an FPR2/ALX- and Nox2-dependent manner.

    Fig. S6. Lesion FPR2/ALX decreases as atherosclerosis progresses.

    Fig. S7. Metabolic parameters of the bone marrow transplant mice described in Fig. 4.

  • Supplementary Material for:

    Targeted nanoparticles containing the proresolving peptide Ac2-26 protect against advanced atherosclerosis in hypercholesterolemic mice

    Gabrielle Fredman, Nazila Kamaly, Stefano Spolitu, Jaclyn Milton, Devram Ghorpade, Raymond Chiasson, George Kuriakose, Mauro Perretti, Omid Farokhzad,* Ira Tabas*

    *Corresponding author. E-mail: iatl{at}columbia.edu(I.T.); ofarokhzad{at}zeus.bwh.harvard.edu (O.F.)

    Published 18 February 2015, Sci. Transl. Med. 7, 275ra20 (2015)
    DOI: 10.1126/scitranslmed.aaa1065

    This PDF file includes:

    • Fig. S1. Engineered NPs with Col IV targeting peptide.
    • Fig. S2. Metabolic parameters of the mice were unaffected by treatment with Col IV–Ac2-26 NPs or controls.
    • Fig. S3. Col IV–Ac2-26 NP treatment does not affect collagen content, superoxide, or mRNA of Il10 or Acta2 in the liver or spleen.
    • Fig. S4. Col IV–Ac2-26 NP treatment does not affect aortic root lesion area or the numbers of lesional macrophages and SMCs.
    • Fig. S5. Ac2-26 decreases 7KC-induced ROS in an FPR2/ALX- and Nox2-dependent manner.
    • Fig. S6. Lesion FPR2/ALX decreases as atherosclerosis progresses.
    • Fig. S7. Metabolic parameters of the bone marrow transplant mice described in Fig. 4.

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