Decorin

Decorin is a is_associated_with::protein that in humans is encoded by the DCN is_associated_with::gene.

Decorin is a is_associated_with::proteoglycan that is on average 90 - 140 kilodaltons (kD) in molecular weight. It belongs to the small leucine-rich proteoglycan (SLRP) family and consists of a protein core containing leucine repeats with a is_associated_with::glycosaminoglycan (GAG) chain consisting of either is_associated_with::chondroitin sulfate (CS) or is_associated_with::dermatan sulfate (DS).

Decorin is a small cellular or pericellular matrix proteoglycan and is closely related in structure to is_associated_with::biglycan protein. Decorin and biglycan are thought to be the result of a is_associated_with::gene duplication. This protein is a component of is_associated_with::connective tissue, binds to is_associated_with::type I collagen is_associated_with::fibrils, and plays a role in matrix assembly.

Naming
Decorin's name is a derivative of both the fact that it "decorates" is_associated_with::collagen type I, and that it interacts with the "d" and "e" bands of fibrils of this collagen.

Function
Decorin appears to influence is_associated_with::fibrillogenesis, and also interacts with is_associated_with::fibronectin, is_associated_with::thrombospondin, the complement component C1q, is_associated_with::epidermal growth factor receptor (EGFR) and transforming growth factor-beta (is_associated_with::TGF-beta).

Decorin has been shown to either enhance or inhibit the activity of is_associated_with::TGF-beta 1. The primary function of decorin involves regulation during the is_associated_with::cell cycle.

It has involved in the regulation of is_associated_with::autophagy, of is_associated_with::endothelial cell and inhibits is_associated_with::angiogenesis. This process is mediated by a high-affinity interaction with is_associated_with::VEGFR2 ( vascular endothelial growth factor receptor) which leads to increased levels of tumor suppressor gene called PEG3. Other angiogenic growth factors that decorin inhibits are is_associated_with::angiopoietin, hepatocyte growth factor (is_associated_with::HGF) and platelet-derived growth factor (is_associated_with::PDGF).

Decorin has recently been established as a is_associated_with::myokine. In this role, it promotes muscle is_associated_with::hypertrophy by binding with is_associated_with::myostatin.

Clinical signifiance
is_associated_with::Keloid scars have decreased decorin expression compared to healthy is_associated_with::skin.

Animal studies
Infusion of decorin into experimental rodent spinal cord injuries has been shown to suppress scar formation and promote axon growth.

Decorin has been shown to have anti-tumorigenic properties in an experimental murine tumor model and is capable of suppressing the growth of various tumor cell lines. There are multiple alternatively spliced transcript variants known for the decorin gene. Mutations in the decorin gene are associated with is_associated_with::congenital stromal corneal dystrophy.

Interactions
Decorin has been shown to interact with:
 * is_associated_with::Collagen type I
 * is_associated_with::Epidermal growth factor receptor  and
 * is_associated_with::TGF beta 1,
 * is_associated_with::TLR2, and
 * is_associated_with::TLR4.