title: 7-Ketocholesterol induces inflammation and angiogenesis in vivo: a novel rat model.
abstract: Accumulation of 7-Ketocholesterol (7KCh) in lipid deposits has been implicated in a variety of chronic diseases including atherosclerosis, Alzheimer's disease and age-related macular degeneration. 7KCh is known to be pro-inflammatory and cytotoxic to various types of cultured cells but little is known about its effects in vivo. In this study we have investigated the effects of 7KCh in vivo by implanting biodegradable wafers into the anterior chamber of the rat eye. The wafers were prepared using a mixture of two biodegradable polymers with different amounts of 7KCh. The 7KCh-containing implants induced massive angiogenesis and inflammation. By contrast, no angiogenesis and very little inflammation were observed with cholesterol-containing implants. The neovessel growth was monitored by fluorescein angiography. Neovessels were observed 4 days post implantation and peaked between 7 to 10 days. The angiography and isolectin IB(4) labeling demonstrated that the neovessels originated from the limbus and grew through the cornea. Immunolabeling with anti-CD68 suggested that the 7KCh-containing implants had extensive macrophage infiltration as well as other cell types. A significant increase in VEGF was also observed in 7KCh-containing implants by fluorescent immunolabeling and by immunoblot of the aqueous humor (AH). Direct measurement of VEGF, IL-1β and GRO/KC demonstrated a marked elevation of these factors in the AH of the 7KCh-implants. In summary this study demonstrates two important things: 1) 7KCh is pro-angiogenic and pro-inflammatory in vivo and 2) implants containing 7KCh may be used to create a novel angiogenesis model in rats.
authors: Mechanism of Retinal Diseases Section, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America.
authors: Juan
authors: J
authors: Amaral
authors: Jung Wha
authors: JW
authors: Lee
authors: Joshua
authors: J
authors: Chou
authors: Maria M
authors: MM
authors: Campos
authors: Ignacio R
authors: IR
authors: Rodríguez
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism; D001082:Aqueous Humor / Q000187:drug effects / Q000378:metabolism; D016510:Corneal Neovascularization / Q000139:chemically induced* / Q000378:metabolism / Q000473:pathology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D007150:Immunohistochemistry; D007249:Inflammation / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology; D007653:Ketocholesterols / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D008297:Male; D019736:Prostheses and Implants; D021381:Protein Transport / Q000187:drug effects; D051381:Rats; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D000097382:CD68 Molecule
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D007653:Ketocholesterols; D042461:Vascular Endothelial Growth Factor A; C067980:CD68 antigen, human; D000097382:CD68 Molecule; C003001:7-ketocholesterol