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Keratocan and lumican play an essential role in corneal transparency of the eye


SLRP Class II organizationCorneal transparency of the eye is associated with keratan sulfate-containing proteoglycans (KSPGs) such as lumicankeratocan, and mimecan/osteoglycin. Lumican and keratocan are the most abundant keratan sulfate carrying proteins found within the collagen matrix of the corneal stroma and are necessary for its proper structure. Mouse models of the cornea help further our understanding of ocular disease and reveal critical insights into the function of these proteins.

Normal keratocan expression in adult tissues is limited to the corneal stroma and is considered a phenotypic marker for keratocytes. In keratocan knockout mice (Kera-/-) the corneal stroma is thinner, the cornea-iris angles are narrower and the collagen fibers of the corneal stroma are disorganized when compared to wild-type animals. In humans, mutations of the keratocan gene (KERA) are associated with the human disease called Cornea plana (CNA2). This disease is characterized by a flattening of the forward convex curvature of the cornea and has been associated with glaucoma. Ultimately, this leads to a decrease in light refraction. Present research is focused on using adult stem cells to regenerate tissue and corneal transparency within knockout mice. Additionally, the understanding of keratocan in the corneal inflammatory response is a topic of interest.

Lumican (LUM) is the major keratan sulfate proteoglycan of the cornea and it binds collagen fibrils. In noncorneal tissues, lumican is present as a low or nonsulfated glycoprotein and has been found in the aorta, cartilage, liver, skeletal muscle, kidney, pancreas, brain, placenta and lung. Complications of the cornea have been confirmed using lumican-null mice. These mice exhibit corneal opacity, skin fragility, and impaired collagen fibrillogenesis. More recent studies show lumican has an integral role in cell migration, adhesion and proliferation. The expression of lumican has also been examined in breast, pancreatic and colorectal cancer. The affect of lumican depends on the type of cancer as it has been shown to have both a positive and negative affect on tumor growth.

MD Bioproducts offers two monoclonal antibodies for detecting the localization and expression of lumican and keratocan in various research applications.

Product:Qty/size:Catalog #
Keratocan Antibody100ug1042008
Lumican Antibody100ug1042007

Suggested Review Articles:

Lumican, a small leucine-rich proteoglycan. Nikitovic D, et al. (2008) IUBMB 60(12):818-23.

Roles of lumican and keratocan on corneal transparency. Kao WW, Liu Cy. (2002) Glycoconj J. 19(4-5):275-85.

Biological functions of the small leucine-rich proteoglycans: from genetics to signal transduction. Schaefer L, Iozzo RV. (2008) J Biol Chem. 283(31):21305-9.