Interleukin 18 binding protein (IL18-BP) inhibits neointimal hyperplasia after balloon injury in an atherosclerotic rabbit model.
OBJECTIVE
Interleukin 18 (IL18) is an interferon (IFN)-gamma-inducing factor and a proinflammatory and proatherogenic cytokine. IL18 binding protein (IL18-BP) functions as an IL18 inhibitor. This study was designed to investigate whether systemic administration of IL18-BP could inhibit neointimal hyperplasia and arterial lipid deposition.


METHODS
New Zealand white, male rabbits were fed with a 21% fat, 0.15% cholesterol diet. The left superficial femoral artery (SFA) was de-endotheliazed with a 2F arterial embolectomy catheter. IL18-BP (5 microg, 10 microg, or 25 microg), or 0.9% saline (control) was administered by i.v. bolus during surgery. Rabbits were followed-up at 2 and 4 weeks. Intima-media (I/M) and lumen-whole artery (L/A) area ratios, and luminal areas were measured. Serum lipid levels, liver enzymes, and kidney function were evaluated. Inflammatory cells were quantified and further verified with immunohistofluorescence staining. The extent of lipid deposition in the artery wall was quantified with Oil Red O (ORO) staining employing Zeiss AxioVision 4.6.3. Image analysis software. Lipid laden cells including macrophages were evaluated by transmission electron microscopy (TEM).


RESULTS
Intravenous IL18-BP 5 microg, 10 microg, and 25 microg significantly reduced I/M ratios compared with the control group at both 2 and 4 weeks. There was no significant difference between the 5 microg and 10 microg dose groups. However, at 10 microg, IL18-BP significantly increased L/A ratio more than either the 5 microg IL18-BP or control groups. The high fat diet caused significant elevation of serum lipids at 4 and 6 weeks. IL18-BP had no effect on blood lipid levels. Lipid deposit in the thoracic aorta of the control group at 6 weeks was more than at 4 weeks (P = .025). Administration of IL18-BP inhibited the lipid deposition at 4 weeks (not significant) and 6 weeks (P = .012 to .008) compared with its control group. Lipid laden macrophages (foam cells), as well as endothelial cells and smooth muscle cells were seen in the descending thoracic aorta after 6 weeks of a high fat diet by ORO, immunohistofluorescence staining, and TEM. The lipid laden cells were not seen in either of IL18-BP groups. IL18-BP 10 microg significantly inhibited mono/macro adherence and infiltration in the SFA after balloon-injury at 2 weeks after surgery.


CONCLUSIONS
A single intravenous dose of IL18-BP significantly decreased arterial neointimal hyperplasia, improved lumen to artery ratio after balloon-injury and also prevented arteriosclerosis progression.


CONCLUSIONS
A single intravenous dose of IL18BP decreased neointimal hyperplasia and improved arterial L/A ratios in an atherosclerotic balloon-injury animal model. These preliminary results suggest that IL18BP may be a promising molecular approach to inhibit neointimal hyperplasia and arteriosclerosis progression following coronary and peripheral angioplasty.
Li
Jian-Ming
JM
Department of Surgery, Division of Vascular Surgery, University of Massachusetts Medical School, Worcester, MA 01655, USA. jianming.li@umassmed.edu
Eslami
Mohammad H
MH
Rohrer
Michael J
MJ
Dargon
Phong
P
Joris
Isabella
I
Hendricks
Gregory
G
Baker
Stephen
S
Cutler
Bruce S
BS
D000800:Angioplasty, Balloon / Q000009:adverse effects*; D000818:Animals; D050197:Atherosclerosis / Q000188:drug therapy / Q000209:etiology / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D004041:Dietary Fats / Q000009:adverse effects; D004195:Disease Models, Animal; D018450:Disease Progression; D004305:Dose-Response Relationship, Drug; D005263:Femoral Artery / Q000187:drug effects* / Q000293:injuries / Q000378:metabolism / Q000473:pathology; D006965:Hyperplasia; D007249:Inflammation / Q000209:etiology / Q000517:prevention & control; D007275:Injections, Intravenous; D036341:Intercellular Signaling Peptides and Proteins / Q000008:administration & dosage*; D007677:Kidney Function Tests; D050356:Lipid Metabolism / Q000187:drug effects; D008055:Lipids / Q000097:blood; D008111:Liver Function Tests; D008297:Male; D051379:Mice; D011817:Rabbits; D011994:Recombinant Proteins / Q000008:administration & dosage; D013997:Time Factors; D017539:Tunica Intima / Q000187:drug effects; D017540:Tunica Media / Q000187:drug effects
D004041:Dietary Fats; D036341:Intercellular Signaling Peptides and Proteins; D008055:Lipids; D011994:Recombinant Proteins; C118370:interleukin-18 binding protein