Intelectin-1, also known as Omentin, HL-1, and Lactoferrin Receptor, is a multifunctional protein that plays a protective role in the response to cardiovascular injury (1). Mature human Intelectin-1 contains one fibrinogen C-terminal domain (2-4) and shares 82% and 80% aa sequence identity with mouse and rat Intelectin-1, respectively. Intelectin-1 is expressed by vascular smooth muscle and endothelial cells (3, 5, 6), particularly in the heart, small intestine, colon, thymus, ovary, testis, and omental fat (2, 3, 6) as well as by intestinal Paneth cells and airway and intestinal goblet cells (7-9). It is presented as a 35-40 kDa GPI-anchored glycoprotein that forms disulfide-linked homotrimers (2, 4) and can be released into the circulation and bronchiolar lavage fluid (6, 8). It binds to microbial galactofuranosyl carbohydrates (2, 11) and additionally functions as a receptor for the iron-transporting protein Lactoferrin (4). Following cardiovascular injury, Intelectin-1 limits fibrosis, cardiac hypertrophy, and carotid artery intimal hyperplasia (12, 13) foam cell generation [5], smooth muscle cell proliferation, migration, and calcification (5, 12, 14), and it also promotes revascularization (15). In addition, Intelectin-1 inhibits osteoblast bone matrix mineralization (14), enhances
insulin-stimulated uptake by adipocytes (6), supports neural stem cell viability (16), and inhibits the invasion and metastasis of neuroblastoma cells (17).
